Method and device for subcutaneous injection with electrical stimulation of nerve

PRIORITY CLAIM

[001] This application is a partial continuation of application for US patent No. 15/062,685, filed March 7, 2016, and application for US patent No. 15 / 141,231, filed April 28, 2016. This application also claims priority for provisional application for US patent No. 62 / 242,745, filed October 16, 2015. The disclosures of each of the above patent applications are hereby incorporated by reference in their entirety.

FIELD OF TECHNOLOGY

[002] The present invention relates generally to improvements in drug delivery and, in particular, to systems for subcutaneous injection / aspiration into a patient's body. More specifically, the present invention provides a method and apparatus for performing an injection that provides the physician with feedback during the subcutaneous placement of the needle.

BACKGROUND

[003] In various medical procedures, it is desirable 4 to position the needle in a specific area to administer a drug solution, such as an anesthetic or analgesic. Two such examples are regional anesthesia by blocking the epidural tissue space and blocking the peripheral nerve (PNB). With respect to epidural anesthesia, in order to achieve effective regional anesthesia and blockade of nerve transmission into the central nervous system, an appropriate volume of local anesthesia solution should be injected in close proximity to the spinal cord at a certain level of the spinal column within the anatomical region known as the epidural "space". For peripheral nerve blockade, the target nerve is identified, and the needle is placed in close proximity to deliver an anesthetic to the nerve. Each of these procedures has complexities related to the relevant anatomy.

[004] Epidural space refers to the part of the spinal canal that is not occupied by the dura mater and its contents. It lies between the dura mater and the periosteum, covering the spinal canal from the inside. The epidural space extends from the large occipital foramen to the sacral fissure. The anterior and posterior roots of the nerves, coated, pass through the epidural space and are combined between the vertebral bodies and intervertebral discs. The epidural space on the lateral side is limited by the periosteum of the legs of the vertebral arches and intervertebral openings. The epidural space at the back is limited by structures such as the periosteum of the anterior surface of the laminae, the articular processes and their connective ligaments, the periosteum of the base of the spinous processes, and the spaces between the laminae filled with a yellow ligament. The specified space contains venous plexuses and adipose tissue, continuously connected with adipose tissue in the paravertebral space.

[005] The fluid-filled epidural space posterior epidural space) is a limited anatomical region of irregular shape with an area of ​​several square millimeters relative to the cross section of the vertebrae and spine. Said fluid-filled space is extremely narrow and is located in close proximity to the shell of the spinal column, with the yellow ligament located in close proximity to it. Thus, during insertion of the epidural needle, it is desirable to know when the tip of the epidural needle enters the fluid-filled space after piercing the yellow ligament. If the needle continues to advance after its tip enters the indicated fluid-filled space, the needle may pierce the dura mater.

[006] The attending physician palpates the spinal column at an appropriate level between the vertebrae. Local anesthesia is performed through superficial tissues, which leads to their local anesthesia. Then, the dermis is punctured using a Tuoha needle and the needle is advanced, while the doctor simultaneously presses on the plunger of the syringe. The pressure exerted on the piston inadvertently leads to a continuous exit of the fluid volume from the needle into the tissues.

[007] Unfortunately, if the epidural procedure is not performed correctly, or if the doctor’s attention is distracted during this procedure, the needle may be advanced beyond the intended target space and may damage the spinal cord. It is known that from 2% to 3% of all injections are performed beyond the intended target space and penetrate through the dura mater until the needle comes into direct contact with the space in which the cerebrospinal fluid is located, and in some cases, to direct contact with the spinal cord, which can lead to a life-threatening situation. Thus, accurate and thorough visual attention of a physician should be maintained throughout the procedure to monitor the exact location of the needle when it is inserted into the epidural space.

[008] In addition, when moving the Tuohi needle after determining the exact location of the epidural space, the needle can be accidentally pulled out of the epidural tissue space when the syringe is removed or due to an accidental movement of the patient or doctor’s arm or, in the worst case, is advanced into the hard shell of the spinal cord, resulting which causes the so-called “wet touch”, which can have dangerous long-term effects on the patient’s health. Even if initially the exact location of the epidural space was properly determined, with further advancement of the needle during the injection of the anesthetic solution into the spinal cord, a large dose of the anesthetic solution can be injected, which leads to temporary or irreversible damage to the nerves.

[009] In addition to the disadvantages described above, pressure monitoring can be complicated by moving the needles forward into the tissue during penetration. When advancing the needle in the tissues, in accordance with Newton’s third law, pressure is generated that counteracts pressure. The pressure of the fluid discharged from the tip of the needle is counteracted by the counter force created when the needle moves through the tissue. This counteracting counter force introduces an error in the measurement of outlet pressure, in particular, if pressure monitoring is carried out on a continuous basis in real time during the advancement and injection of the drug into the tissue. Inhomogeneous movement when moving the needle into the tissue array causes pressure surges, and errors in the pressure measurement results can lead to false positive confirmation of the maximum outlet pressure.

[0010] Below with reference to FIG. 12 describes the histology of the peripheral nervous system. The basic element of the central and peripheral nervous systems is a single cell unit, commonly known as an axon. The brain and central nervous system are made up of millions of axons. Branches from the central nervous system of the brain stem and spinal cord are a combination of highly organized axons, through which a network of sensory and motor pathways is formed. Together, this network of pathways is known as the peripheral nervous system.

[0011] In the peripheral nervous system, each individual axon is surrounded by supporting connective tissue called endoneuria. The endoneuria contains small blood vessels (capillaries and venules) that deliver nutrients to the indicated axons. Axons collectively form highly organized tightly packed fibers that are surrounded by a thin but dense multilayer shell of connective tissue that surrounds these fibers and forms a membrane structure called perineurium. Perineurium provides a dense protective layer, which is a physical and chemical barrier that provides a sufficient degree of protection for axons and endoneuria. This barrier is akin to the blood-brain barrier.

[0012] This separate formation of endoneuria and perineuria is called peripheral nerve fiber. When the nerve fibers join together, they form fascicular bundles coated with epineuria, which is the connective tissue, sometimes called internal epineuria. Many groups of nerve bundles are located in a heterogeneous matrix of connective tissue (adipose tissue), in which there are medium-sized vessels that are freely located together with the outer dense connective tissue. The bundle fascicular structures surrounded by this additional, densely and highly organized layer of fibrous tissue called the external epineuria are peripheral nerves.

[0013] The outer epineurium, as the outer layer, is in contact with neighboring structures. Loose connective tissue fills the space between the nerve and surrounding tissue in conjunction with external epineuria. Thus, there is an additional multilayer border outside the external epineurium, which runs along the entire length of the nerve and consists of extraneural neural tissue known as paraneuria. Laranevrii is a distinguishable multilayer functional structure that allows the nerve to slip relative to other anatomical structures during musculoskeletal movements.

[0014] In 1912, electrical stimulation was proposed to facilitate the location of a nerve branch. Electrical nerve stimulation was introduced based on the understanding that nerve transmission is an electrochemical excitation reaction transmitted along a nerve (axon). The use of electric stimulation of the body made it possible to detect indirect excitation of both sensitive fibers and motor nerve fibers. It turned out that when applying electrical stimulation, a visible muscle contraction occurs. When modulating the frequency and intensity of the discharge, contractions and relaxation of muscle groups innervated by the nerve branch were observed. Such an application of an indirect electric discharge to cause the reaction of a specific nerve is not widespread, since the attending physicians did not have the ability to accurately control various parameters of the applied current. Disadvantages, known since the time of the first stimulation of the nerve, exist today and include:

- The inability to accurately modulate the electrical discharge at given distances applied to the surface in the projection of the nerve branch limits the benefits of nerve stimulation in identifying a particular nerve branch when nerve stimulation is used as the primary means of determining the location of the nerve branch. For specific distances, when approaching a nerve branch blindly, various discharge intensities in the range from 2.0 mA to 0.2 mA are recommended. However, there is no correlation between distance and intensity, determined by a visible reaction in the form of muscle contraction. Thus, more intense stimulation, causing a visible reaction, does not necessarily mean that the needle is at a greater distance from the intended branch of the nerve. And a visible reaction to a less intense electric discharge does not mean that the needle is in a position closer to the surface extraneural and / or is located within the nerve, i.e. reached the intra-neural position. Indeed, apparently, there is no unanimous opinion regarding the location of the needle (intraneural or extra-neural), determined on the basis of the reaction to an electric discharge, regardless of its intensity, frequency and duration, applied to the nerve at a given distance.

- Another disadvantage of the method of stimulation of the nerve is the impossibility of setting the appropriate discharge for a certain distance from the outer surface of the nerve bundle, i.e. with extrafascial position. The situation is even more aggravated if an intense discharge of more than 1.0 mA is used in the intrafasicular position, since it can cause a severe reaction in the patient or, even worse, the result will be irreversible damage due to excessive electric discharge applied directly to the axon. Thus, it is impossible to determine which appropriate discharge should be applied for a specific distance from the nerve bundle.

- Another drawback is that the distorting factors do not allow nerve stimulation to be considered the exact way. These factors relate to the anatomical variations in a given patient, as well as the anatomical variations between different patients. The body consists of tissues of various types, which include connective tissue from mineralized and non-mineralized tissues. These tissues are composed of water and collagen, adipose tissue (fat), muscle tissue, fluids (blood), bones, cartilage, etc. The fabrics of each of these types have different electrical resistance and / or charging capacity when the discharge is applied to the intended target at a given distance. Fabric variation cannot be underestimated and impossible to predict. Therefore, known devices have the disadvantage of being unable to quantify the intensity of a particular discharge for a particular location. This leads to an inability to elicit a predicted response to a given electrical discharge when it is used as the primary means for determining the location or proximity to a particular nerve.

[0015] Summarizing the above, variables such as discharge intensity, frequency, and tissue electrical resistance do not allow standardizing the method to enable location of a particular nerve branch.

SUMMARY OF THE INVENTION

[0016] In light of the disadvantages of the prior art, the present invention provides an injection system that improves the reliability and safety of injections, in particular injections, which are performed to identify fluid-filled cavities in the body in narrow layers of fascia or connective tissue. Based on information, in particular, the results of continuous monitoring of pressure projected onto the surface of the patient’s body at the needle insertion site, the operator can carefully and continuously monitor the movement of the needle while receiving critical injection parameters, such as outlet pressure, flow rate, warnings, threshold changes output pressure values, as well as any important information that is usually displayed elsewhere. This approach allows the operator to always concentrate visual attention on the injection site.

[0017] In addition, according to another aspect of the present invention, there is provided a device and method providing a mechanism for an operator to continuously guide the needle, while receiving visual information projected onto the surface of the patient’s body at the injection site, and thus allowing the operator to continuously hold needle field of view and injection site to continuously maintain accurate hand-eye coordination. This information can be provided in various forms from color changes, images, numbers, words and visual changes to forms such as intensity, blinking, coordinated lighting patterns, etc.

[0018] According to another aspect of the present invention, there is provided a medication administration device that continuously monitors the pressure of a fluid introduced into a subject's body. Then, the measured pressure resistance can be continuously converted into a visual signal. Then, the measurement results are presented to a specialist physician so that he can determine or confirm whether the drug being delivered is delivered to a given tissue. In addition, measurements are also recorded for later viewing and documentation of the clinical case. Upper pressure thresholds, as well as control of the drug injection rate, can be predefined to exclude the possibility of using excess pressure and / or drug injection rate during this process.

[0019] According to yet another aspect of the present invention, there is provided a method and apparatus for using back pressure to calculate outlet pressure. Counter pressure depends on the needle insertion speed. Thus, the system comprises a mechanism for controlling the rate of insertion of the needle. In particular, the system may include marks on the needle, as well as auditory or visual cues to suggest an appropriate needle insertion rate.

[0020] According to another aspect of the present invention, there is provided a hand unit to which a marked needle is connected, configured to receive a small display device, such as a light emitting diode or a display screen, that reproduces a blinking or visual instruction, and / or a speaker a beep or a sound that may be intermittent, to ensure coordination of the specified movement of the needle forward with the specified visual or sound signals in relation to the movement of the needle based on these marks on the surface of the needle when it penetrates through the skin or other part of the body. Sound and visual modulations determine the speed of advancement of the needle so that the speed of advancement of the needle can be coordinated with moving forward to increase the accuracy of determining the occurring counter pressure used in calculations during monitoring of outlet pressure in real time.

[0021] According to one aspect of the present invention, a mechanism is provided for distinguishing between the intrafascicular and extrafascicular arrangement of the needle.

[0022] According to another aspect of the present invention, a current discharge is transmitted through an ionic solution through a disposable syringe and a tube to the tip of a needle to stimulate a nerve.

[0023] According to another aspect of the present invention, there is provided a system that provides a constant flow of fluid from the tip of a needle while moving the needle through tissues while performing a peripheral nerve block, to prevent the tip of the needle from being inserted into the nerve bundle. The constant flow of fluid from the tip of the needle acts as a means to displace or repel dense structures from the tip of the needle as it moves.

[0024] According to another aspect of the present invention, there is provided a system that provides a specific speed or pace of movement of the needle forward in the tissue to prevent biasing force of counter pressure applied to the needle when it advances the specified needle into and through the tissue, with simultaneous and continuous measurement pressure at the tip of the needle.

[0025] According to another aspect of the present invention, when the needle does not advance, the counter pressure is not subtracted from the pressure head when calculating the outlet pressure. It should be understood that the button or control on the hand unit can also be activated to correspond to forward movements at which the counter pressure is subtracted from the pressure in calculating the pressure, and thus, means are provided to distinguish between the state when the needle is moving and the state when the needle remains stationary within the tissue.

[0026] The present invention also provides a hand unit to which a marked needle is connected, and which is designed to accommodate a small light emitting diode or display screen and / or loudspeaker, the blinking and / or sound signal of which are coordinated with the indicated advancement speed of the specified needle . According to one embodiment, the manual unit comprises input devices for controlling the rate of drug administration, electric current stimulation and communication with the central processor of the execution unit. In addition, according to one embodiment, the hand unit comprises a vibration chip or element to provide vibration to the hand unit to transmit a command or signal from the central processor to the operator. This sensation of vibration may be discrete and may present a command warning or signal to the operator requiring his response. According to yet another embodiment, the hand unit also comprises an output display device for further displaying information.

[0027] According to the present invention, there is also provided an injection device for blocking a peripheral nerve that uses a maximum back pressure range of 75 mmHg. (10.0 kPa) up to 500 mmHg (66.6 kPa) to trigger electrical stimulation. Instantaneous discrete current supply can be provided when a specific pressure value is detected within the pressure range. This signal is designed to control instantaneous discrete current supply at a specific pressure value within a specified pressure range.

[0028] According to another aspect of the present invention, the system uses a bias pressure value set in the central processor, which is determined by the speed (pace) and correlates with the speed (pace) of forward movement of the marked needle in the tissue. The bias pressure value is calculated and taken into account when calculating the pressure value to exclude pressure bias caused by counter pressure on the needle resulting from moving the needle forward while using continuous flow and pressure monitoring.

[0029] According to another aspect of the present invention, an injection device is provided that provides a current of 0.15 mA to 2.0 mA. Current is provided in response to a determined outlet pressure value. In addition, the electric discharge must operate for a discrete period of 1.0 sec to 10.0 sec. At the same time, when an electric discharge is operating, a control signal is transmitted to the central processor that requires a response. An example of a response to a control signal:

i) confirmation of muscle contraction;

ii) changing the rate of administration of the drug to a higher one for dosing the drug.

[0030] According to another aspect of the present invention, there must be a first state (a specific outlet pressure value at a constant flow rate) and a second state (electric current stimulation) requiring an operator response to set a third state (presence / absence of observation) to obtain a result on output (instructions and warning signal).

[0031] According to another aspect of the present invention, there is provided a device that provides a means for advancing a needle in tissues with a speed of advancement in the range of 2 mm / s to 20 mm / s with a constant flow of fluid at a particular drug injection rate.

[0032] According to yet another aspect of the present invention, there is provided a method and apparatus for using back pressure to calculate outlet pressure. Counter pressure depends on the needle insertion speed. Thus, the system comprises a mechanism for controlling the rate of insertion of the needle. In particular, the system may include marks on the needle, as well as auditory or visual cues to suggest an appropriate needle insertion rate.

[0033] According to another aspect of the present invention, there is provided a hand-held unit to which a marked needle is connected, and which is configured to accommodate a small display device, such as a light emitting diode or display screen, that provides a blinking or visual instruction, and / or speaker giving a sound signal or sound tone that may be intermittent, to enable coordination of a specific forward movement with the specified visual or audio signal to advance the needle based on markers on the surface of the needle when it penetrates through the skin or other part of the body. Sound and visual modulation determine the speed of advancement of the needle in such a way that the speed of advancement of the needle can be coordinated with moving forward to increase the accuracy of determining the occurring counter pressure used in calculating the output pressure, monitored in real time.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The foregoing disclosure and the following detailed description of preferred embodiments of the present invention will be best understood by reading with reference to the accompanying drawings, in which:

FIG. 1 shows a perspective view of a drug delivery system;

FIG. 2 shows a perspective view of the drug delivery system shown in FIG. 1, without injection unit;

FIG. 3 shows a side view of the injection unit for the drug delivery system shown in FIG. 1;

FIG. 4 shows a local side view of an alternative injection unit for the drug delivery system shown in FIG. 1;

FIG. 5 shows a functional diagram of a drug delivery system shown in FIG. 1;

FIG. 6 shows a functional diagram of a system for drug delivery according to another embodiment;

FIG. 7 shows a screen shot of a display monitor for the drug delivery system shown in FIG. 1;

FIG. 8 shows an enlarged fragmentary sectional view of a portion of a patient's spinal column with yet another embodiment of a drug delivery system;

FIG. 9 shows a schematic view of the drug delivery system shown in FIG. 8, when used by a patient;

FIG. 10 shows a side view of a needle assembly according to another embodiment configured to connect to the drug delivery system shown in FIG. 1;

FIG. 11 shows a graph of fluid pressure versus time when a needle is inserted in an epidural drug procedure;

FIG. 12 shows a sectional view of a nerve bundle with nerve fibers;

FIG. 13 is a side view of an injection device for a drug delivery system shown in FIG. 2; and

FIG. 14 shows a flowchart of a fluid injection method .

DETAILED DESCRIPTION OF THE INVENTION

[0049] In the drawings in general and in FIG. 1-3, in particular, a system for drug infusion is shown, generally indicated by reference numeral 5. System 5 comprises a disposable injection unit 10 and a computer-controlled drug delivery tool 50, called an execution unit. The injection unit 10 comprises an insertion needle 24 adapted to be inserted into the body of a mammalian subject. The injection unit 10 is connected to an execution unit 50, which during use controls the flow of fluid to the injection unit. System 5 also includes one or more output devices that provide data to a specialist physician during the procedure to assist in the proper insertion of a needle into the subject's body.

[0050] The system 5 is configured to determine the exact location of a fluid-filled tissue, such as an epidural space, intra-articular space, an eyeball, cysts, blood vessels, and other fluid-filled body cavities. The system is also configured to deliver the drug to such a fluid-filled tissue. The drug may contain, inter alia, local anesthetics, such as corticosteroids, hydroxyapatite, complementary drugs, sclerosing agents, and other drugs that are usually injected into the tissue-filled tissue space for therapeutic purposes.

[0051] The injected fluid is absorbed into the tissues at different rates. As a result, the fluid pressure changes. Thus, this fluid pressure (or internal pressure related to tissue resistance pressure) indicates several types of tissue and can be used to identify different types of tissue.

[0052] System 5 provides the attending physician with the ability to accurately identify a fluid-filled tissue space while limiting the placement of drugs in non-target tissues. This applies to both diagnostic and therapeutic procedures. System 5 uses the pressure of the fluid flowing from the needle or catheter after placing the needle / catheter in the tissue to identify placement accuracy and monitor placement during injection or aspiration.

[0053] In particular, system 5 comprises one or more output devices for providing visual feedback regarding the detected fluid pressure in the insertion needle. The operator uses visual feedback as a control during placement of the opening needle. As shown in FIG. 1 and 2, the first output device may be a video display screen, such as an LCD for displaying data to assist an operator. In addition, a second output device may also be provided. For example, the second output device may be a light emitting element configured to provide an output signal that is in the field of view of the operator during the procedure. For example, the second output device may be a light emitting element configured to project a light beam onto the patient’s body near the area where the needle is inserted into the patient’s body.

INJECTION NODE

[0054] As shown in FIG. 3-4, the system 5 comprises a disposable injection unit 10 which comprises a syringe 18 and an elongated length of flexible tube 22 having a first end connected to the syringe and an insertion needle 24 connected to the second end. Thus, fluid from the syringe can be expelled through the tube 22 into the needle 24. The injection unit 10 also includes a pressure sensor for detecting the pressure of the fluid in the injection unit. The pressure sensor may be located in one of several locations for measuring pressure, which correlates with the pressure of the fluid at the tip of the needle 24. In this case, the pressure sensor 20 is an integrated fluid pressure sensor attached to the syringe 18 between the syringe and the tube 22. Thus The pressure sensor 20 measures the pressure of the fluid when the fluid exits the syringe and enters the tube 22 to which the insertion needle 24 is connected.

[0055] A computer-controlled drug delivery system 50 in the system shown in FIG. 1-2 provides many benefits to patients through accurate injection. An output cable 21 connects the pressure sensor 20 to the drug delivery system 50, so that the drug delivery system can change the fluid flow from the syringe in response to data from the pressure sensor 20. Thus, the drug delivery system 50 provides accurate and safe administration of drugs for various applications, such as epidural anesthesia, intraarticular and other subcutaneous injections. The connection 12 is connected to the second cable 23 and the connector 30, which is inserted into the tool 50. The pressure sensor 20 is connected in series between the front end 19 of the cylinder of the syringe 18 and the first end 25 of the tube 22. One exemplary connection is a Luer connection for connecting a pressure sensor 20 to the tip of a syringe. Said connection may be fixed by a threaded connection and / or a non-reversible threaded connection, such as a Luer lock type connection. According to another embodiment, in this case, the pressure sensor 20 is permanently attached to the syringe by welding in a plastic state or by a chemical bonding component such as an adhesive. Thus, the instantaneous actual fluid pressure in the drug delivery line 22 is recognized and used by the instrument, which provides an accurate approximation to the actual instantaneous fluid pressure at the point of the needle 24 or at the tip of the needle 24 and, thus, at a location in the patient’s body where the tip of the needle is located. The electronic pressure sensor 20 transmits pressure data via electronic data cables 21, 23, which are connected directly to the central unit 50 for collecting pressure measurement results.

[0056] The disposable injection unit 10 is in the form of a disposable consumable kit in which all components are connected, and in this case, the connection is permanent. For example, the components of the injection unit can be bonded together by welding or glue, epoxy or other adhesive, i.e. the syringe 18 is constantly connected to the electronic pressure sensor or transducer 20 permanently connected between them installed in the tube 22. This disposable unit 10 is used and disposed of as a separate unit. It is also connected to the execution unit 50 by means of a second connector 16, which can be inserted into the connector 14 in a key manner to ensure that only authorized disposable nodes 10 are used and that these nodes are used only once.

[0057] The electronic pressure sensor 20 may be any of various pressure sensors. One example of a sensor type is a piezoelectric pressure sensor, such as sensors commercially available from Merit Medical Systems, Inc, such as a Meritrans® brand pressure sensor model MER212.

[0058] According to a preferred embodiment, permanent needle attachment may be optional so that the attending physician may select the preferred needle for a specific purpose. The components are assembled individually or according to a preferred embodiment, are glued (i.e. connected) together and provided in the form of a single disposable kit for which appropriate disposable components have been selected.

[0059] A preferred embodiment is a connected disposable kit. It is contemplated that various configurations may be used in conjunction with tool 50. They consist of components of various sizes, i.e. needle, syringe, set of tubes and pressure sensors. The system may include an identifying connector that uniquely identifies the details of each injection unit (e.g., needle size, tube length, etc.). The inclusion of an identifying connector in the kit allows you to confirm and identify the intended one-time use. This approach provides verification of the system, which facilitates the use of appropriate components and / or drugs. It is contemplated that the pre-filled syringe 18 may be provided with an injection unit 10, or the syringe may be empty so that it can be filled in place with the necessary medication, saline or other fluid. For prefilled syringes 18, the identifying connector 12 contains (in the microchip) information related to the drug contained in the syringe.

[0060] In FIG. 4 shows parts of a disposable injection unit according to another embodiment. This embodiment includes an axially elongated rigid plastic sterile handle 27 attached to the second end of the tube 22 and having a connector, such as a Luer lock plug, which must be separable in connection with a needle 24 selected for a particular type of injection into the selected anatomical site. The elongated handle 27 according to this embodiment facilitates manual control and the accuracy of the placement of the needle, in particular due to the rotary control. This is, in particular, useful for intra-articular (IA) injections (i.e., lower alveolar injections), and may also facilitate the execution of other types of epidural injections. The elongated handle 27 preferably has a length of about 15 cm (about 6 inches), or its length is in the preferred range of about 10-20 cm, with a tube 22 having a length of about 122 cm (about 48 inches).

AUTOMATED FLUID DELIVERY SYSTEM

[0061] As described above, system 5 includes a fluid delivery system 50 for providing a controlled flow of drug to the injection unit 10. Preferably, the fluid delivery system is an automated system and in this case is a computer-controlled fluid delivery system called an execution unit 50 .

[0062] As shown in FIG. 1-4, the specified executing unit is designed to work in conjunction with a disposable injection unit 10. The executing unit has a semi-cylindrical syringe slot 52 located on the upper surface of the executing unit 50, as shown in FIG. 2. The specified socket is configured to receive a syringe 18 of the injection unit 10. A pair of spring clips interacts with the syringe to hold the syringe in the socket 52. The transverse groove in the nest is configured to interact with a finger rest 88 at the end of the syringe barrel. Thus, the palm rest of the syringe barrel interacts with the groove 55 and prevents the axial displacement of the syringe barrel relative to the seat 52. The seat 52 further comprises a portion adapted to receive the piston 70 of the syringe 18. As shown in FIG. 1, said seat has a length that allows the syringe barrel and piston to be received into the seat when the piston is extended to the rear end of the piston cylinder. In particular, the length of the seat is greater than the maximum length of the syringe in its extended state, so that the syringe can be placed in the seat without interacting with the piston when the piston is extended out of the cylinder to the maximum length.

[0063] The executing unit 50 comprises a movable platform 58 having three spring-loaded latches or hooks 60 for abutment under the thumb, which are pivotally mounted on the platform 58. The executing unit 50 controls the displacement of the movable platform for controlling the release of fluid from a syringe. In particular, the platform 58 is movable along the axis of the seat 52 for pushing the piston 70 into the barrel of the syringe. Initially, platform 58 is moved forward to interact with the piston. In particular, the platform moves forward (to the right relative to the perspective view shown in FIG. 1) until the chamfered surfaces of the three hooks begin to interact with the emphasis 72 under the thumb of the piston 70. Continuous displacement of the platform 58 forces the emphasis on the thumb to wedge the hooks 60 radially outward until the hooks extend radially outward beyond the outside diameter of the thumb rest. As the platform 58 continues to advance, the beveled surfaces of the hooks 60 pass past the thumb rest 72, and at this point the hooks snap closer to each other behind the thumb rest 72, so that the platform reliably interacts with the thumb rest, and the platform moves leads to displacement of the piston.

[0064] After the platform 58 has grasped the palm rest, the sensor in the execution unit 50 recognizes the resistance to further movement of the platform 58, and the platform stops. At this stage, the piston 70 is actually axially attached to the platform 58 due to the interaction of the latches 60 with the emphasis 72 under the thumb. Thus, further movement from left to right of the platform 58 also causes the piston 70 to move to the right with the displacement of the fluid from the syringe body. Similarly, any retraction of the platform (i.e., moving to the left relative to FIG. 1) causes the fluid to be sucked back into the syringe body.

[0065] The pressure sensor 20 of the assembly 10 is inserted into the proprietary connector 12, and the connector 12 is connected to the block 50 via the connector 30. The microprocessor or central processor 82, the electronic circuit board 92, the power supply 94 and the electronic motor or motors are located in the execution block 50 96 (since two syringes can be used, as shown in FIG. 5-6). Each electronic motor 96 rotates a worm shaft 98, which moves the syringe fittings 90 in the front or rear direction. The syringe fitting 90 comprises a load cell for detecting force. The armature 90 is connected to the platform 58 with the possibility of moving the platform in any direction. As indicated above, the disposable injection unit 10 comprises an identification and connection component 12, a syringe 18, an in-line pressure sensor 20, a set of 22 tubes and a needle 24.

[0066] The execution unit 50 is configured to provide a constant or variable fluid flow. In this case, the execution unit may provide an intermittent fluid flow in response to signals received from the electronic pressure sensor 20, which continuously senses the pressure of the fluid during the injection / injection procedure. Based on a predetermined pressure, the execution unit 50 may stop the fluid flow when the determined pressure exceeds a predetermined threshold value. The predetermined threshold value can be set by the attending physician and stored in the storage device 80 of the microprocessor or computer 82 located in the electronic part in the execution unit 50. Similarly, based on a predetermined pressure, the fluid flow resumes when the fluid pressure drops below the predetermined pressure. The same target pressure can be used to control the termination and resumption of fluid flow. In this case, the pressure will increase until the fluid initially enters the tissue to a predetermined level, and then the flow will stop until the pressure drops below this predetermined level. After the fluid pressure drops below a predetermined level, the fluid flow will resume. Thus, the fluid flow can begin and stop during the procedure, turning into an intermittent fluid flow.

[0067] The system may include predefined pressure thresholds used to control the flow of drug from the syringe 18 during the procedure. This allows the attending physician to selectively administer drugs to specific locations and targeted tissues for diagnostic and therapeutic procedures. The pre-selected maximum allowable pressure limits and / or flow rates are stored in the memory 80 and determine the maximum recommended pressures to which patients are typically exposed or other criteria. When the pressure approaches this threshold value, optical and / or sound alarms are generated for the attending physician, i.e. on the screen 62 and through the loudspeaker 84, which are activated by data from the microprocessor 82. In addition, data describing the entire injection process is stored in memory 80 for subsequent analysis.

[0068] The system 5 can directly measure the pressure of the fluid in the injection unit 10, or the system can measure a characteristic indicating the pressure of the fluid in the injection unit. For example, pressure can be measured by determining the pressure resistance measured during infusion. The measured pressure resistance is continuously converted into a visual signal during the injection procedure. However, drug consumption during the procedure can be based on fluid pressure detected in real time during the procedure. Thus, the consumption of the drug varies and depends on the pressure in the system. Thus, fluid pressure may be the primary control variable of the system.

[0069] Thus, the drug injection rate becomes a secondary variable that is modulated within a predetermined range to support the required fluid flow. In one particular embodiment, the fluid flow stops when the pressure exceeds a predetermined threshold value (maximum pressure). The rate of administration of the drug as a secondary variable may be limited so that fluid injections are not performed too quickly at low pressure. It is contemplated that the relationship between pressure and fluid flow may be binary or continuous. Binary communication exists when an injection device is configured to deliver a fluid at a single predetermined flow rate for any pressure that is less than a predetermined maximum value. Thus, the fluid flow is resumed or stopped based on whether the pressure exceeds the specified threshold value. According to another embodiment, the flow rate can also be modulated as a function of pressure. In this case, the flow rate will decrease as the pressure approaches the maximum allowable value and increase when the pressure drops. According to another embodiment, the flow rate may be limited by the first predetermined maximum pressure and may resume at a second predetermined pressure different from the first.

[0070] As indicated above, system 5 may include a mechanism for displaying relevant injection data, including, for example, instantaneous flow rates, pressures, and volume of injection on the screen 62 of execution unit 50. Similarly, the system may include a mechanism for recording such information for later analysis after the procedure. For example, the system may comprise a non-volatile electronic storage device, such as a hard disk drive, flash drive, optical drive, or other medium for storing electronic data.

[0071] All measurements and information can be presented to the attending physician "in real time" so that the attending physician can determine whether the injection is delivered to the intended location and / or correctly defined tissues, and modify the injection process accordingly. In addition, measurements can be recorded for later viewing and documentation of a clinical case.

[0072] It is also contemplated that a plurality of syringes that are actuated by individual pistons can be used to enable the administration of a plurality of drugs, as well as a second syringe drive that does not require a predetermined pressure to be achieved for any of the above purposes. The second drive can be programmed to a specific drug delivery rate to allow the infusion of a drug, such as a local anesthetic and other therapeutic drugs, into various tissues.

[0073] According to yet another embodiment, the device may comprise two distinguishable syringe actuators, both of which are modulated based on fluid pressure, as described above in this application.

VISUAL PRESSURE INDICATOR

[0074] As shown in FIG. 1, the system comprises a visual signal generator 100 for generating visual signals corresponding to fluid pressures detected by the system. The visual signal generator 100 provides feedback for the operator to guide the operator during insertion of the needle 24 into the body of the subject. In particular, visual signals from the visual signal generator 100 provide continuous signals related to the proximity of the needle tip to the intended location, such as a space filled with fluid.

[0075] The visual signal generator 100 may be any of various light indicators. For example, as shown in FIG. 1, the visual signal generator may include a light head 105 mounted on the end of the flexible cable 102. The flexible cable 102 can have sufficient rigidity so that the cable can be bent to the desired position to achieve the desired orientation and hold this position without external support. Thus, the operator can position the lighting element so that the light head 105 is directed to the surface that is in the field of view of the operator, while the attention of the operator is focused on the injection site on the patient's body. For example, light from a lighting element may be projected onto a surface adjacent to the body of the subject, such as a wall or other flat surface. According to yet another embodiment, preferably, the light head 105 may be positioned so that it projects a light beam onto a patient. For example, light from a lighting element may be directed directly to the skin or clothing of a subject. More specifically, light can be projected onto the patient’s body near the injection site so that the light signals from the visual signal generator 100 are within the operator’s field of view, while the operator visually tracks the injection site. Thus, visual signals from the visual signal generator 100 provide the operator with useful information regarding the injection, without forcing him to look away from the injection site.

[0076] The light head 105 may comprise any of various lighting elements. For example, the light head 105 may comprise a light emitting diode, an incandescent lamp, a laser diode, or any other light emitting element. In addition, the lighting element 105 may comprise a plurality of such light emitting elements. As well as the lighting element 105 may contain many lighting elements that change the light intensity, color and / or coherence. Despite the fact that the light head 105 may contain one or more scattered light elements, preferably the light head 105 provides a light beam that is coherent enough to project onto a patient and is easily distinguishable to the operator during the procedure. Therefore, the light head 105 may include a lens 107 for focusing the light of the lighting element (s), as shown in FIG. 2.

[0077] The light generated by the visual signal generator 100 is controlled by the execution unit 50. In particular, the visual signal generator 100 is controlled in response to electrical signals from the microprocessor 80 of the execution unit 50. The execution unit may comprise a separate control circuit that controls the visual signal generator 100 in response to control signals received from the microprocessor 80 of the execution unit. In particular, the electronic control device for the lighting circuit may be configured to separately control each of the plurality of lighting elements in the light head 105. The light control circuit may control each lighting element by turning it on or off. The light control circuit can control the intensity of each lighting element. In addition, the light control circuit may control combinations of lighting elements to change the light generated by the visual signal generator. For example, a light control circuit may employ combinations of lighting elements to change the color of the light flux emitted by the light head 105. For example, a light head may comprise a plurality of red, green, and blue lighting elements, and an electronic light control device may selectively control the illumination of multi-colored lighting elements to create a beam of light having red, yellow, or green, or any of various colors.

[0078] According to yet another embodiment, the light control circuit may control the lighting elements to create varying patterns of light projected by the visual signal generator. For example, a visual signal generator may project a beam of light having a specific pattern. According to one embodiment, the visual signal generator 100 projects a first colored signal when the pressure sensor 20 determines the pressure within the first range; and a visual signal generator may project a second colored signal when the pressure sensor detects pressure within the second range. Furthermore, when the pressure sensor detects a signal approaching a threshold value between the first range and the second pressure range, the visual signal generator can project a beam in which one distinguishable part of the beam has a first color and the other distinguishable part of the beam has a second color.

[0079] In addition to controlling light intensity, color, and pattern, the light control circuit can control the light blinking frequency. In particular, the light may be intermittent, so that a ray of light flashes and goes out. The on / off cycle frequency can be controlled in response to the pressure determined by the system. The light control circuit may control a visual signal generator based on the absolute value of the detected pressure. According to another embodiment, the light control circuit may control the indicator based on the relative value of the detected pressure, indicating the current value relative to the most recently detected pressure. Thus, the light control circuit can change the light depending on whether the pressure increases or decreases. Similarly, the light control circuit can control the light based on both the absolute and relative values ​​of the detected pressure. For example, a light control circuit may control lighting elements to generate a light beam having a specific color based on a detected pressure within a specific pressure range. In addition, based on the relative pressure indicating that the pressure is rising, the light control circuit may cause the visual signal generator to flash in a selected color. In addition, the light can be controlled so that the flashing frequency increases with increasing pressure to the upper end of the pressure range. As soon as the pressure increases beyond the pressure range, so that the pressure is already at the lower end of the second pressure range, the light control circuit can control the visual signal generator so that it generates light of different colors, flashing at a low frequency when the pressure is in lower end of the second pressure range.

[0080] From the foregoing, it is understood that the visual signal generator 100 can provide an enormous number of colors and patterns that can provide continuous feedback signals to the operator with a view to using them for guidance during the needle insertion procedure. Some examples of the specific method are described below, according to which the visual signal generator 100 can provide continuous feedback light signals.

[0081] As described above, the visual signal generator can project the light beam onto any of various surfaces, which allows the operator to see the light signal while maintaining concentration on the injection site. The following describes how light is projected onto the patient’s body. It should be understood that this description is given only as an example of the surface onto which the light is projected.

[0082] The execution unit 50 may be programmed so that the visual signal generator projects yellow light when the detected pressure is in the range of 0-20 mmHg. (0-2.7 KPa), green light when the detected pressure is in the range of 20-40 mm Hg. (2.7-5.3 KPa), and red light when the detected pressure is in the range of 40-200 mmHg. (5.3-26.7 KPa). Light may flash when pressure increases. Thus, the visual signal generator projects a flashing yellow beam onto the patient when the needle is inserted into the patient’s body and the pressure rises to a threshold pressure of 20 mmHg. (2.7 kPa). As soon as the pressure rises to 20 mmHg (2.7 kPa), the indicator light changes so that a green light beam is projected onto the patient. And the light blinks as pressure rises. If the pressure remains constant, the light also remains constant (i.e., without blinking). In addition, when advancing the needle and increasing the pressure to 40 mmHg (5.3 kPa) the flashing frequency increases until the pressure reaches 40 mmHg. (5.3 kPa). At this point, the flashing frequency decreases significantly, and the color of the light beam changes to red.

[0083] In the above description, the visual signal generator provides a continuous feedback signal corresponding to the detected pressure, so that the operator can easily recognize various data on the detected pressure, including, in addition to pressure, the rate of change of pressure and the direction of pressure change (increase, decrease) or slight change . It should also be understood that the visual signal generator can provide color signals that indicate a warning, alarm, system error or failure, or any other various system failures that require attention of the operator. For example, in the above example, red is used to indicate that the fluid pressure is within a specific range. In yet another embodiment, a red color (or any other color) may be intended to indicate a warning, error, or other alarm. Thus, when the visual signal generator 100 projects a red beam or flashes a red beam, the operator is easily notified of a problem that needs attention.

[0084] Furthermore, in the above description, the visual signal generator 100 provides a beam that corresponds to a specific condition or output pressure characteristic for the injection unit. It should also be understood that the absence of light from the visual signal generator can also be used to provide information to the operator. For example, the visual signal generator may be turned off so that light is not projected when pressure drops within a certain range. For example, if the pressure is below 10 mmHg. (1.3 kPa), the visual signal generator can be turned off.

[0085] In addition to various colors and patterns, the visual signal generator 100 may provide graphical and / or human readable information, including but not limited to numbers, letters, and symbols. For example, the visual signal generator 100 may project a numerical value of the pressure detected by the pressure sensor 20. Thus, the operator can easily see the pressure change in real time, without distracting his attention from the injection site and the needle that he is manipulating. In addition, graphical information can be combined with color changes or a template to provide the operator with additional information. For example, a visual signal generator may project a numerical value of a pressure detected in real time. In addition, the color of the projected numbers may change when the pressure changes from one pressure range to the next, as described above. Similarly, a quantity can be projected with a constant color, such as a dark color, and quantities can be embedded in a background having a color that relates to a specific pressure range or other characteristic, as described above.

[0086] Of course, the graphic information projected by the visual signal generator is not limited to alphanumeric characters. The visual signal generator can provide graphic data of any various types. For example, a visual signal generator can project a graph of detected pressure values ​​for a long time so that the operator can see a graphical illustration representing the pressure change on the graph, including the magnitude of the change, the rate of change, and various inflection points. Similarly, the displayed data should not be limited to real-time pressure values ​​detected by the pressure sensor 20 or otherwise obtained. The data projected by the visual signal generator may contain information such as the rate of injection of the drug or fluid through the injection unit 10, the volume of fluid in the syringe, the elapsed time since the start of the injection of the needle, and patient data. Accordingly, it should be understood that the visual signal generator can be performed and controlled in such a way as to project any visual data that can be presented on the screen of the display device, such as an LED screen, an LCD screen or a CRT screen. The visual signal generator will project such visual data in a way according to which the operator can easily see this data without performing special actions to obtain it and without distracting his attention from the manipulation of the needle.

[0087] In the above description, the visual signal generator 100 is a lighting element that projects visual feedback for the operator to use in the direction of introducing the needle into the body of the subject. In the above embodiments, the visual signal generator 100 is mounted on a semi-rigid shoulder or cable connected to the execution unit so that the lighting element can be located at a desired location and oriented so that light can be projected onto the desired target area. In FIG. 4 shows a visual signal generator 200 according to another embodiment. According to this embodiment, a visual signal generator is mounted on an element of a disposable injection unit 10 and / or connected directly to said element. In particular, the injection unit 10 comprises an elongated sleeve 27 connected to a fluid pipe 22. The sleeve 27 comprises a mounting member for connecting the needle 24 to the sleeve. For example, sleeve 27 may comprise a Luer connector.

[0088] As shown in FIG. 4, the visual signal generator 200 may be mounted on an elongated sleeve or otherwise connected to the elongated sleeve. Thus, the sleeve 27 is an elongated rigid element for supporting the visual signal generator 200. The visual signal generator projects the visual signal in the forward direction, for example, on the patient’s body or near the injection site. Thus, the visual signal generator can project a beam whose axis is parallel or substantially parallel to the axis of the needle 24. The visual signal generator comprises an elongated cable 206 so that the visual signal generator can extend far from the execution unit 50. In particular, cable 206 comprises a connector for connecting a visual signal generator to an execution unit in order to receive control signals from the execution unit, as described above with reference to the above embodiment.

[0089] A visual signal generator 200 mounted on the sleeve 27 is arranged to project a light beam onto the injection site. In particular, the visual signal generator is installed so that at least a portion of the light beam 202 emitted by the visual signal generator is parallel to the axis of the input needle 24. In particular, the visual signal generator can be connected to the needle so that a substantial part of the light beam 202 parallel to the axis of the needle.

[0090] According to another embodiment, the visual indicator is a lighting element, such as one or more fiber optic elements, that provide a visual light signal around an elongated tube 22 or through an elongated tube 22 of the injection unit 10. Thus, light can be projected into the fluid in the tube so that the light signal is next to the needle due to the fact that the needle is connected to the tube and the light is projected onto the needle or patient due to the fiber optic elements passing along the tube 22. Accordingly, it should be understood that the visual signal generator can be of any design that provides a visual signal projected onto a surface that is easily visible to the operator, without distracting the attention of the operator from the injection site.

[0091] Thus, the advantages of the present device compared with the prior art include:

(i) a mechanism for projecting an image representing the pressure at the exit to the surface of the patient’s body so that it is possible to determine the moment of identification of the fluid-filled tissue space, such as epidural space, intraarticular space, eyeball, cysts and blood vessels or other vessels of the body with fluid in addition to the above structures;

(ii) a mechanism for enabling the operator to continuously maintain a visual field at the needle insertion site on the patient’s body while simultaneously projecting information onto the needle injection site and eliminating the need for a remote visual screen or from having to look at the screen to obtain said visual information;

(iii) a mechanism configured to track the outlet pressure in a sequence of predetermined ranges in which the light emitting source enables the operator to objectively distinguish threshold values ​​between different ranges by means of a distinguishable visible change, such as a color change; and

(iv) a mechanism configured to monitor outlet pressure by means of a projected visual image configured to use flashing patterns and / or flashing patterns to report an upward or downward trend in outlet pressure. This also includes the ability to report a slight change in pressure by providing a visual indication.

CALCULATION OF THE PRESSURE OF THE FLUID AT THE NEEDLE EXIT

[0092] As described above, fluid pressure is used to control the operation of system 5. For example, the visual feedback provided by the visual signal generator 100 is based on a specific fluid pressure. There are various methods for calculating the pressure of the fluid at the exit of the needle.

[0093] The pressure sensor may detect fluid pressure in the injection unit 10. For example, as described above, the pressure sensor may be an in-line pressure sensor, such as a pressure sensor commercially available from Merit Medical part # 0001. According to another embodiment a pressure sensor integrated in the execution unit 50 can detect the pressure of the fluid between the syringe 18 and the set of 22 tubes. According to yet another embodiment, a strain gauge located in the thrust of the thumb syringe is used to determine the force acting on the piston to calculate the pressure in the syringe. The command signal from the pressure sensor transmits pressure data to the central processor for calculation in order to determine the outlet pressure. The outlet pressure is calculated in accordance with the mathematical formula according to which the pressure in each component proximal to the point of pressure measurement is subtracted. In addition, the calculated value is provided relative to the counter pressure (acting against pressure), which correlates with the specific rate (i.e. speed) of the needle moving forward through physiological tissues. Thus, the pressure value is an input parameter, and the calculated pressure value is calculated taking into account all the expected resistances of the system to calculate the final objective pressure value at the outlet. The central unit of the execution unit uses input values ​​and setpoints specified in the software for calculation. The final calculated pressure value at the outlet is used to control the central processor and control the motor, which controls the flow of fluid from the syringe 18.

[0094] As indicated above, the counter pressure can be subtracted from the measured pressure to determine the final fluid pressure value. The counter pressure changes in response to the injection rate, and the counter pressure is subtracted from the measured fluid pressure when calculating the outlet pressure of the fluid. For example, the following values ​​represent counter pressure values ​​for various needle insertion speeds.

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[0095] Since the needle insertion speed significantly affects the counter pressure, it is desirable to control the needle insertion speed. Accordingly, the system may include a manual unit 300, designed to assist the user with the insertion of the needle at a controlled and known speed. In this case, a reusable manual block is used. However, it should be understood that the means of the hand unit can be used with a disposable needle assembly.

[0096] As shown in FIG. 10, the hand unit 300 includes a hollow body 310 and an elongated hollow needle 340 extending forward from the body. A connector 332 is provided for connecting the hand unit to the fluid line 22 of the injection unit 10. In particular, the connector 332 provides a watertight seal to connect the hand unit 300 at the rear end of the housing to facilitate the connection of the hand unit to the fluid in the syringe. Fluid flows into the hand unit and flows through the needle 340.

[0097] The needle 340 comprises a plurality of marks 344 located along the needle body. In particular, the marks contain many lines drawn across the axis of the needle. Marks 344 are located at a certain known distance from each other. In particular, each mark 344 is located at the same distance from the adjacent mark. The marks are preferably located at least along a substantial portion of the length of the needle. In this case, the marks extend from the tip 342 of the needle 340 to the connection between the body 310 and the needle. The marks indicating the increment can be applied to the surface of the needle by laser etching with alternating colors or engraving on the surfaces of the needle at a certain distance, such as, for example, increments of 1.0 cm.

[0098] The hand unit 300 may also include a light indicator 215 configured to provide the operator with regular prompts. The indicator light 315 may be a light emitting diode or other lighting element that glows at a predetermined frequency depending on the intended rate of administration. In particular, before starting the procedure, the operator enters various data regarding the procedure, and based on these data entered by the operator, the needle insertion rate for the procedure is determined. Based on the needle insertion speed, the flashing frequency of indicator 315 is determined. As described in detail below, the light indicator works like a metronome, which is a constant rhythm-setting element for tracking the speed of needle insertion in order to improve the accuracy and stability of the needle insertion speed.

[0099] The hand unit further comprises an audio indicator 320, such as a piezoelectric audio indicator, for delivering an audio signal, such as a buzz, tone or ringing. The sound indicator 320 works like a light indicator 315, emitting a regular tone, which can be used to set the rhythm for the speed of introduction of the needle 24.

[00100] In addition, a control button 325 may be present in the hand unit. The control button 325 may act as an on / off button. However, the control button can also be configured to enter various control commands. For example, the control button 325 may be configured to cancel one or more operations of the execution unit 50, as described in detail below.

[00101] Finally, the hand unit 300 may also include an output device, such as a screen of a display device for displaying various information, such as the frequency of the light indicator 315 and / or the sound indicator 320. In addition, the display device can display additional information, such as real-time pressure values ​​or “Continue”, “Change position”, “Enter” alerts, Input speed 1, Input speed 2, Low speed, High speed, “Aspiration” .

[00102] As described above, the hand unit contains visual and audible indicators 315, 320. Of course, the hand unit does not have to contain both audible and visual indicators; It can contain only one indicator. In addition, although the visual and sound indicators are described above, various other alternative indicators, such as a vibration element, which provides regular vibration indicator signals, can be used instead.

[00103] A certain sound / visual modulation indicates to the operator the need to advance the needle forward in a specific increment based on marks 344 on the needle. Moving forward by the value of a specific increment is counted after the surface of the needle penetrates into the surface of the skin, dermis or body part into which the needle penetrates. Speed ​​from 0.5 cm / s to 2.0 cm / s is presented as the range of movement of the needle. The exact speed of movement is achieved by coordinating sound or visual modulation with the movement of a marked needle that penetrates the surface, and this movement is noticeable by visual marks on the surface of the needle, indicating specific distances. The marked needle then advances one increment (one mark) through the surface of the tissue in accordance with one “beep” and / or “blink”.

[00104] The speed of the audio and / or visual prompts is set in the central processor and is activated by the fluid stream. A range of 0.5 cm / s to 2.0 cm / s is provided, however, it is understood that any speed of coordinated incremental movement of marks representing the movement of the needle can be used. This forward speed, selected from the set values, enters the corresponding counter pressure value, which will be subtracted from the calculation result when determining the objective tissue pressure value.

[00105] As an example of the operating speed, the operator advances the needle 1.0 cm with each beep and visual “blinking” of the light emitting diode to ensure coordination of the exact speed of the needle. This approach provides the ability to maintain accurate needle advancement speed. In addition, during the advancement of the needle, a continuous flow of fluid from the needle is provided, and continuous pressure monitoring in real time is provided.

[00106] As indicated above, the hand unit 300 may include a control button. The control button can be used when the needle does not advance. In this case, pressing the button causes the control signal to be sent to the execution unit 50 so that the counter pressure value is not subtracted from the output pressure calculation result (since the needle does not advance, there is zero or essentially zero counter pressure). It is understood that a button or control on the hand-held unit 300 can also be activated to correspond to forward movements at which the counter pressure is subtracted from the result of the calculation of the pressure head, and thus, means are provided for distinguishing when the needle is moving and when it remains stationary in the fabric. Thus, the activation of the 325 button during periods with the needle insertion speed from minimum to zero contributes to the accuracy of the pressure at the exit of the needle into the tissue during the procedure. In addition to the switch or control button described above, the hand unit may contain a second button or control element, the use of which during reverse movements would add an additional pressure value as compensation for reverse movement, which causes a decrease in the pressure values ​​at the exit when the needle moves back through tissue.

[00107] In the above description, the hand unit contains a visual or audible indicator 215, 220 for setting the rhythm of the needle insertion speed. Despite the indicator (s) that can be mounted on the hand unit, the visual signal generator 100 described above can be used to supply visual signals to set the rhythm of the needle insertion speed. In particular, the visual signal generator 100 can project a visual signal at a constant and predetermined speed or frequency, like the flashes of the indicator light 315. Since the visual signal generator 100 projects light near the injection site or in the field of view of the injection site, the operator can see the signal light for the rhythm of the introduction of the needle. Thus, as indicated above, the needle can be used separately from other devices of the hand unit. In particular, a needle with tags for controlling the rate of administration can be used with a conventional injection unit, such as the injection unit 10 described above. According to this embodiment, the visual signal generator provides visual cues for controlling the needle insertion rate.

[00108] Since the skin color of different people may vary from patient to patient, it is desirable to use an element that provides a unified indication of the signals when they are projected onto the patient's body. For example, it may be desirable to attach a background element onto which a visual signal can be projected. An exemplary background element may be a flexible patch that can be applied directly to the patient’s skin near the intended administration site. The patch may be made of any various flexible materials, such as fabric, paper or plastic.

[00109] The patch has a working side on which visual signals are to be projected, and a reverse side adapted to be attached to the patient. Preferably, the reverse side comprises an adhesive substrate, so that the patch can be easily attached directly to the skin of the patient. For the adhesive backing, any of various known adhesives can be used to remove the connection to the patient’s body. The working side of the patch can be made in accordance with any of various patterns, but preferably the working side is solid. In addition, preferably, the color of the patch is selected to enhance the contrast between the projected visual signal and the patch. For example, if the projected visual signals are generally dark in color, the patch may have a slightly tinted hue, such as white or almost white. Conversely, if the projected signals are generally light in color, the patch may have a dark shade, such as black.

[00110] Performed as described above, the adhesive backing of the patch can be pressed against the patient's body to adhere the patch to the patient. Preferably, the patch is applied next to the intended injection site, for example, on the patient’s back next to the spine. The visual signal generator is directed onto the patch, and then the visual signal generator projects visual signals as described above.

METHOD FOR INTRODUCING INJECTION INTO A FILLED-FILLED SPACE IN THE PATIENT'S BODY

[00111] An exemplary method for administering an epidural injection to a patient using the system described above is described below. Of course, the proposed system is not limited to using only epidural injections for administration. Accordingly, it should be understood that the principles and methods described below can be easily adapted for injection into tissues and anatomical areas in addition to the epidural space.

[00112] The connective tissues of the body can create pressures above 200 mmHg. (26.7 KPa) with the introduction of a fluid at a speed of 0.07 ml / s. Each tissue has its own characteristics of pressure density, presented as measurable pressures that can be detected in tissues of this type. Tissue density or resistance is measured using fluid pressure introduced from a computer-controlled drug delivery system configured to determine pressure resistance during infusion. It has also been found that fluid-filled cavities, such as epidural tissues, intraarticular space, or body vessels, have pressures measured during injection that are well below 200 mmHg. (26.7 kPa). In fact, it turned out that the fluid-filled cavities have significantly reduced pressure resistance to the fluid flow and usually have pressure resistances close to zero when tissue portions are introduced into these fluid-filled media.

[00113] The first predetermined upper pressure limit is determined by the attending physician. Typically, the first predetermined upper pressure limit is not more than 200 mm Hg. (26.7 kPa). Using these settings, the injection system 50 injects a small amount of the drug into the patient’s connective tissue and then selects a second preset pressure below 50 mmHg. (6.7 kPa), at which the fluid flow resumes. Therefore, the needle is properly positioned within the fluid-filled epidural tissue space, since the pressure in the epidural tissue space is presumably from about +15 mmHg. (+2 KPa) up to -15 mmHg (-2 KPa), while the pressure inherent in the yellow ligament (Ligamentum Flavum) is above 200 mmHg. (26.7 kPa).

[00114] The measured pressures outside the ligamentous tissue are typically about 100-200 mm Hg. (13.3-26.6 KPa). Using an injection device 50 having a second predetermined pressure at which fluid flow resumes, i.e. 50 mmHg (6.7 kPa) or lower, there is no significant fluid flow when the needle enters the subcutaneous tissue, since the pressure rises rapidly and persists while the needle is in the subcutaneous tissue (extra-ligamentous tissue). The attending physician encounters a yellow ligament when the Tuohi needle is inserted. In this case, the fluid flow does not occur, because, as indicated above, the yellow ligament exerts a pressure of more than 100 mm Hg (13.3 kPa). After penetrating through the entire thickness of the yellow ligament (i.e., when the needle enters the epidural space filled with fluid), the pressure drops sharply to below 50 mmHg. (6.7 kPa), as a result of which an additional visual imaging device is launched and / or an audible tone occurs and / or a voice message sounds, such as “Epidural space detected”. At this point, the drug-containing fluid will begin to flow into the intended target area. Thus, an intermittent fluid flow is used to identify target tissues. It is possible that the first and second values ​​of the set pressure are set the same to allow the resumption of the fluid flow only after the pressure drops below the set value.

[00115] The pressure sensor 20 or a plurality of sensors of the injection device 50 provide an automatic safety function in the event that the injection needle leaves the epidural tissue space (for example, due to an error of the attending physician or movement of the patient), or when the open vessel of the patient is threatened. If the needle 24 leaves the epidural tissue space when it is removed through the yellow ligament or in contact with the dura mater, the pressure immediately rises to the first selected value of P1, which leads to a slowdown and possible stop of the fluid flow at a fluid pressure of more than 200 mm Hg . (26.7 kPa). It was found that this process takes about 2 seconds (see Ghelber-Regional Anesthesia and Pain Medicine, Volume 33, No. 4, 2008, p. 349, FIG. 2). If necessary, this pressure change from &lt;50 mm Hg (&lt;6.7 kPa) to&gt; 200 mmHg (&gt; 26.7 kPa) again starts the supply of an optical and / or sound signal to alert the attending physician about the incorrect placement of the needle. The flow again automatically resumes after the needle returns to the epidural tissue space and the instantaneous pressure at the tip of the needle decreases below the value of P1, or according to another embodiment of the present invention, after reducing the pressure to a second selected pressure value of P2, which is equal to or lower than 50 mm Hg. (6.7 kPa). This automatic protective function of the injection device helps prevent the injection of anesthetic solution into the spinal cord.

[00116] In FIG. 8 shows a portion of a vertebral column of a subject for epidural injection. Starting from the outer injection site for the tip of the needle 24 on the left in FIG. 8, tissues in this region include various layers of skin, adipose and connective tissue 110, behind which is located the epidural space 112, which is the anatomical space of interest according to one embodiment of the present invention. Behind the epidural space 112 is the hard shell 114 of the spinal cord 116. The tip of the needle 24 directed to the right passes through the tissue, but stops before reaching the spinal cord. In this section, the bones of the spinal column are also shown in a section.

[00117] In this case, the microprocessor 82 and the storage device 80 are programmed to use a first pressure P1 of, for example, approximately 200 mmHg. (26.7 KPa), which is equal to or greater than the instantaneous pressure of the fluid at the tip of the needle when it penetrates and moves through the fabric 110. At a pressure of P1 or higher, the engine 96 is stopped and the flow of fluid to the tip of the needle is stopped. When the tip of the needle penetrates the epidural space 112, the instantaneous fluid pressure drops below the value P1, and the microprocessor starts the engine again to resume the flow of fluid now into the epidural space 112 according to one embodiment. According to a second embodiment, in order to resume the fluid flow, it is necessary that the second selected pressure value P2, which is stored in the memory 80, is reached. According to a third embodiment, upon reaching the third selected pressure value P3 stored in the memory 80, which is greater than P2 but less than P1, the fluid flow is again stopped. The achievement of this third pressure P3 indicates that the tip of the needle rested on the hard shell 114 of the brain or otherwise left the target anatomical space. The cavities or layers through which the tip of the needle moves correlate with the pressure settings P1, P2 and P3, as shown in FIG. eight.

[00118] The first selected pressure P1 at which the fluid flow is stopped is preferably about 200 mmHg. (26.7 kPa) for epidural injection, but may range from about 25 mmHg. (3.3 KPa) to about 300 mmHg (40.0 KPa) depending on the tissue that the needle tip pierces in the first place. The pressure P2 at which the fluid flow is resumed is preferably about 50 mmHg. (6.7 kPa) for epidural injection, but may range from about 20 mmHg. (2.7 kPa) to about 150 mmHg (20.0 KPa) depending on the anatomical space of interest. The third selected pressure P3, at which the fluid flow is again stopped, is preferably about 125 mmHg. (16.7 kPa) for epidural injection, but may range from about 80 mmHg. (10.7 kPa) to about 180 mmHg (24.0 KPa) depending on the anatomical space of interest. The use of three preset pressure values ​​improves flow on / off control when the tip of the needle moves through tissues of various kinds for any fluid-filled anatomical space capable of receiving fluid at low pressure, unlike the tissues surrounding this anatomical space.

[00119] It is believed that a medium not containing a pharmaceutical preparation is used to identify the epidural tissue space during the phase of the needle placement in the epidural injection procedure. Suitable pharmaceutical-free fluids include, for example, sterile saline, artificial cerebrospinal fluid, Ringer's solutions, 5% dextrose solution, or filtered air. After identifying the epidural tissue space using a differential pressure, the injection fluid is replaced with a pharmaceutical containing fluid. The use of a pharmaceutical-free fluid during the needle placement phase minimizes or prevents the introduction of pharmaceuticals into non-target tissues.

[00120] Another feature of the proposed device and method is the objective nature of the pressure measured by a computer-controlled drug delivery device that monitors pressure during all phases of the injection process. Thus, the attending physician no longer relies on subjective “sensations”, but receives objective information about the absolute values ​​during each phase of this risky operation. Each phase of the method is improved due to the ability to continuously monitor pressure while using an intermittent fluid flow with the drug, which makes it possible to make adjustments that increase the safety and efficiency of the injection.

[00121] According to yet another embodiment, the attending physician may relieve a predetermined maximum allowable pressure after the needle has entered the fluid-filled space and the injection has begun. As indicated above, before the needle penetrates into the epidural space, the fluid pressure is more than 200 mm Hg. (26.7 kPa), with the result that only a small amount of fluid is delivered, or the fluid is not delivered at all. After the needle penetrates the fluid-filled space, the pressure decreases to values ​​below zero and gradually rises to values ​​of about 1-10 mm Hg. (133.3-1333 Pa). This decrease in pressure initiates the flow of fluid from the injection device. At this stage, the maximum pressure setpoint can be changed to a new, reduced maximum. For example, a predetermined maximum pressure at which the fluid flow stops can be reduced to 25 mmHg. (3.3 KPa), which provides an additional level of patient safety in case of contact of the injection needle with the dura mater or removal of the needle from the epidural space. A new predetermined reduced maximum pressure leads to an earlier termination of the fluid flow and with a reduced ectopic volume of injection compared to the initial predetermined value. Changing the set maximum pressure that stops the flow of fluid can be performed manually by the attending physician or automatically by means of a control element in the injection device.

[00122] It should be understood that a value of 200 mmHg (26.7 kPa) as a predetermined maximum set pressure for stopping the fluid flow is only an example, and a lower or higher set pressure can be selected at the discretion of the attending physician. In addition, the value of the second predetermined pressure of 50 mm Hg (6.7 kPa), at which the fluid flow resumes, is given only as an example and is merely illustrative, so that a lower or higher target pressure can be selected at the discretion of the attending physician. The proposed principles and methods can be modified for injection into almost any anatomical region. Of particular importance in this embodiment of the method and device according to the present invention is the ability to determine and select preset pressure values ​​for generating an intermittent drug flow for diagnostic and therapeutic drug administrations.

[00123] The methods described herein are equally suitable for injection into human and animal tissues.

[00124] In FIG. 5-6 are a schematic diagram of the arrangement of tools and electronic components. As shown in FIG. 5, the visual signal generator 100 may be coupled to the central processor 80 of the execution unit 50. In particular, as described above, the central processor 80 may include a separate light control circuit that is configured to control the lighting elements of the visual signal generator 100. In particular, the light control circuit may receive signals from the central processor or other elements of the executing unit and may control the lighting elements in response to the received signal.

FIG. 6 shows an alternative block diagram of the system shown in FIG. 5. As shown in FIG. 6, the visual signal generator 100 is connected to the display screen 62 of the execution unit 50. In particular, the visual signal generator 100 can be connected to a USB hub located on the display device. According to this embodiment, the visual signal generator 100 comprises a light control circuit configured to receive signals from the display device and control the light to provide the necessary visual feedback, as described above. For example, the visual signal generator 100 may be configured to operate as a remote projection screen onto which any image shown on the display device screen 62 can be projected.

FIG. 9 shows an execution unit with an attached light source 100 projecting a light image onto a target surface of a patient’s body and a portion in which a needle is inserted into a patient’s body. The light reports that the needle found a cavity filled with fluid, a change in its color projected onto the surface of the patient’s body.

[00127] The use of the emitted light projected onto the surface of a patient's body provides many advantages that cannot be realized by other mechanisms. In particular, a light emitting element configured to emit light with various colors and / or patterns provides:

(i) a mechanism configured to objectively represent one or more specific pressure thresholds that cannot be transmitted in a continuous acoustic tone;

(ii) a mechanism designed to effectively notify the operator when pressure rises or falls, without subjective interpretation by changing colors and / or patterns of light that are objectively recognized visually as distinguishable indicators;

(iii) a mechanism that allows the operator to focus their field of view on the treatment site, and, in particular, a mechanism in which viewing the remote screen of the display device does not require confirmation by a sound tone or other signal;

(iv) an inexpensive mechanism for transmitting information without the need for a remote display device or accessory screen;

(v) a mechanism that removes the limitations of acoustic feedback in the operating room, in which there are many competing sounds and tracking devices that can distract the operator and lead to medical errors; and

(vi) a mechanism that does not emit sounds that the patient may interpret as a cause for concern during the procedure.

METHOD OF EPIDURAL ADMINISTRATION

[00128] A top view of the instrument shows a recessed cavity 52 and a recess 56, collectively referred to as a syringe slot, which allows the execution unit 50 to receive a standard syringe 18 with a capacity of 20 cc. In the recess 56 for the piston is arranged to move the armature 90 and the platform 58, which interact with the emphasis for the thumb or the flange 72 of the syringe 18 disposable. The mechanism that interacts with the stop of the thumb syringe has several spring-loaded hooks 60 shown in FIG. 1, which automatically locks the stop of the thumb syringe.

[00129] As shown in FIG. 1, to engage the stop of the thumb syringe, the spring-loaded hooks 60 move outwardly over the stop of the syringe 72 and then interact with the stop of the syringe in a hook-like manner. As a result of this action, the stop of the syringe is fixed as shown in FIG. 1, allowing the piston 70 of the syringe to be mechanically moved by platform 58 of the syringe in any direction to aspirate. In addition, a strain gauge is integrated in the design of the valve fitting 90 for the syringe. Valve 90 uses optical and mechanical means to identify the position of the syringe and provides the ability to calculate the volume of fluid in the syringe.

[00130] Step 1: The power of the execution unit 50 is turned on by a corresponding button on a separate side panel 64, as shown in FIG. 5, which contains the On / Off, Start / Stop, Cleaning, and Aspiration On / Off buttons, as well as the battery indicators. The “On / Off” button turns on the power of the execution unit and the touch screen interface of the LCD 62. When the power is turned on, the valve mechanism 90 for the syringe automatically moves to its original position, as shown in FIG. 1.

[00131] FIG. 1, an armature 90 with a movable platform 58 with a receiving receptacle 52, 56 for stopping the syringe for automatic interaction during aspiration is connected to a movable arm for the syringe located on the upper part of the execution unit.

[00132] The upper part of the executing unit has a syringe slot that includes stoppers or clamps 54 located on its surface. These stops 54 interact with the cylinder surface of the syringe 18 when the syringe is placed in the receptacle to create a mutual connection between the syringe and the receptacle.

[00133] Step 2: The execution unit 50 uses the disposable injection unit 10 shown in FIG. 3, which contains the following system components.

[00134] Syringe 18: according to a preferred embodiment, a standard 20 cc syringe is used from Becton Dickinson, Inc. The design is not limited to the specific size or volume of the syringe. The operator loads the syringe with fluid from an appropriate sterile container, such as a multi-dose drug vial or a single-use glass ampoule. The operator can load the syringe completely or load the syringe partially, since the means for auto-detection determines the volume of fluid in the syringe.

[00135] According to a preferred embodiment, an in-line pressure sensor 20 is used, such as a Meritrans® in-line pressure sensor from Merit Medical, South Jordan, Utah. It is contemplated that the strain gauge in the syringe armature can provide information corresponding to fluid pressure and eliminates the need for a secondary pressure sensor.

[00136] The hypodermic needle 24 may be a Tuohy needle, such as a 20Gx3.5 "Tuohy needle from Becton Dickinson, Franklin Leike, NJ. A sterile tube set is a 22-48" type blood pressure tube, such as a sterile tube from ICU Medical, Inc., San Clemente, California.

[00137] As an identifying connector 12, any means for transmitting and communicating to the central processor of the execution unit may be used, including but not limited to infrared radiation, Wi-Fi, Blue Tooth, or other wireless means. Verification of the disposable assembly can also be implemented using automated marking or marking, such as applying a barcode to the injection unit 10, and using a barcode reader to scan a barcode. The barcode may contain an element that acts as a key, so when the system receives a barcode scan of the corresponding injection unit, it opens the execution unit 50 for use. The identifying connector 12 communicates with the execution unit central processor 80 to provide information related to the disposable injection unit 10.

[00138] It is contemplated that additional information may be encoded in the identifying connector 12, such as, but not limited to: drug information, such as drug name and formulation, drug manufacturer, batch number; information related to the disposal of consumables; information related to the expiration of the drug; information related to the sterility of the disposable kit; as well as the date and time of use of the identifying connector.

[00139] In a preferred embodiment, a 20 cc syringe 18 is connected to a Meritans model pressure sensor 20 with an identifying connector 12 attached and a set of 22 48-inch blood pressure tubes. At the distal end of the tube set, a Tuohi needle 24 (hollow) is attached as shown in FIG. 1, 2 and 7.

[00140] Step 3: After inserting the syringe 18 into the syringe receptacle, the operator views the initial screen 62 with the message “Load the syringe and press the Continue button”. The touch screen interface 62 allows the operator to click on the “Continue” button, as a result of which the suction receiver automatically engages with the focus of the syringe for the thumb.

[00141] Step 4: An operator inserts a needle into the patient’s body at the target site. When the operator advances the needle, the system determines the feedback pressure in the needle, and the visual signal generator projects a signal based on the determined pressure. The visual signal changes as the detected pressure changes. The operator continues to advance the needle using visual signals from a visual signal generator to guide the introduction of the needle.

[00142] In the above example, feedback from the visual signal generator is based on the detected pressure. However, as indicated above, the pressure depends on the flow rate of the fluid flowing from the syringe. Accordingly, it should be understood that the signal from the visual signal generator can be at least partially based on the flow of fluid flowing from the syringe into the patient's body.

[00143] The automatic syringe detection function uses the holding hooks of the automatically aspirated suction receptacle to confirm that the appropriate size syringe has been selected. Confirmation is established based on the size of the thumb stop and the diameter between the hooks of the suction receptacle with automatic engagement. If the size of the syringe and the size of the receptacle do not match, the hooks are not engaged. A loaded syringe is initially detected by a load sensor contained in the syringe armature of the execution unit. The forward movement of the syringe automatically stops when resistance is detected on the thrust of the syringe for the thumb. Then the syringe armature reverses the direction of travel after the spring-loaded hooks mesh with the thrust of the syringe thumb. If a reduced diameter stop is used for a syringe whose size is different from the size of a 20 cc syringe. see, the hooking hooks are not engaged, so that the syringe is not detected. In response to an undetectable syringe, the system displays a warning message or sends an appropriate signal, and further use of the execution unit is terminated. For example, the light unit 100 may emit a quick flash of a red warning light prompting the operator to correct the problem with the injection unit.

[00144] The automatic syringe detection function uses an optical and / or mechanical sensor to detect signs of a syringe to thereby determine the volume of fluid in the syringe. The detected volume is shown on the display. After completion and confirmation of the detection of the syringe, the system can automatically flush the set of tubes with an appropriate volume of fluid to fully charge the disposable injection unit 10.

[00145] In the light of the foregoing and as shown in FIG. 11, an example use method is described below that includes using the functions of a visual signal generator 100 and marking a needle 344 along with counter pressure to calculate an outlet pressure. The description below refers to an epidural procedure, but it should be understood that this method can also be applied to other processes, such as a peripheral nerve blockade procedure, in which the pressure of the fluid in the needle is monitored.

[00146] Pre-operator prepares the tool, enters various parameters based on patient information and details of the procedure. In the present example, a hand unit 300 containing an epidural needle is used. The needle has marks located at certain distances from each other, such as sections 1 cm long, the color of which alternates between silver and black. The operator attaches the disposable tube 22 and the pressure sensor 20 to the syringe 18. Then, the visual signal generator 100 is directed to the patient so that the visual signal generator projects a light beam onto the patient near the target injection site. The data that the operator enters into the system sets the required needle insertion speed, which also determines the counter back pressure, which will become part of the calculation when the system determines the outlet pressure.

[00147] The drug delivery tool 50 starts to operate, and light is emitted from the visual signal generator 100. According to this embodiment, a blinking light is emitted to provide a visual indication of how quickly the operator should advance the needle from one mark 344 on the needle to the next. For example, a visual signal generator 100 projects green light onto a patient’s body surface for 2 seconds, and during this 2 second period, the operator must slowly advance the needle to the next mark on the needle near the patient’s skin surface. The light emitting source then switches to black for a very short period of time (0.1 sec). When the light switches back to “green” within the next two seconds, the operator must advance the needle to the next distance defined by marks 344 on the needle.

[00148] The operator continues to advance the needle into the tissue of the patient's body at a certain pace controlled by the blinking pattern. This pattern of 2-second green emitted light, followed by a short period of no light, continues until the pressure rises from point "A" to point "B" in the graph shown in FIG. eleven.

[00149] When the pressure increases between points "A" and "B", the counter pressure value is included in the algorithm for adjusting the output pressure value shown on the screen. During this period, pressure rises with a blinking green light.

[00150] A visual indication of blinking green light at a certain frequency notifies the user of two aspects of the system: 1) The needle must be inserted at a particular rate of insertion of the needle by coordinating the rate of penetration into the skin (which in turn provides the tool with a constant known counter pressure value ); 2) It notifies the operator that the pressure rises from 0 mm Hg. (0 KPa) up to 100 mmHg (13.3 KPa) according to this embodiment. During this period, the execution unit may discharge fluid from the syringe through the needle.

[00151] The operator continues to advance the needle into the patient’s body toward the target layer, which according to this embodiment is the yellow ligament, when performing an epidural injection.

[00152] When the pressure reaches point "B", as shown in FIG. 11, the engine of the execution unit 50 is stopped because the fluid pressure has reached a predetermined pressure limit that has been previously determined. When the engine stops, the execution unit no longer displaces the drug from the syringe. When the pressure reaches this preset value, the tool stops giving an indication of the needle insertion rate by blinking the emitted light.

[00153] This value, if necessary, can be changed by the operator (in this case, it is 100 mmHg (13.3 KPa)).

[00154] Upon reaching point "B" a special emitted visual alert is provided. Various colors can be used for it; according to this embodiment, white light is emitted in this case. This light may be constant or flashing to indicate that maximum pressure has been reached.

[00155] Despite the fact that between the point "B" and "C" the pressure for some time retains the value of 100 mm RT.article. (13.3 kPa), there is no additional visual information related to the movement of the needle. If necessary, the operator can observe on the screen that the pressure value is 100 mmHg. (13.3 kPa).

[00156] The operator continues to advance the needle so that the tip of the needle at point "C" enters the epidural space. A decrease in pressure occurs because the needle is inserted into the epidural space, and the engine of the execution unit 50 begins to displace the piston, thereby displacing the drug from the syringe. However, the pressure decreases in the period between points “C” and “D”. The light emitting source emits a flashing red light indicating that the pressure is falling.

[00157] At point "D", the pressure reaches the inflection point and begins to increase again. Starting from point "D", the emitted light changes between points "D" and "E" and is now represented by a blinking green light that flashes at a given 1-second pace, different from the rate of introduction of the needle in the area between points "A" and "B "

[00158] At the inflection point “E”, the pressure begins to decrease again, and at this point the generator again changes the visual signal to a flashing red light until a predetermined discrete pressure value is determined at the “F” point.

[00159] After reaching the point "F" and the pressure drop below 40 mm RT.article (5.3 KPa) a constant red color is emitted between the points "F" and "G", indicating that the output pressure value is between 40 mmHg. (5.3 KPa) up to 20 mmHg (2.7 kPa).

[00160] After passing the point "G", the pressure drops to a value of 20 mm RT.article. (2.7 KPa), and solid blue light is emitted, indicating that the pressure has reached a minimum value, and the outlet pressure is in the range of 20 mmHg. (2.7 KPa) up to 0 mmHg (0,0 KPa).

[00161] At this point, the identification of the epidural space is confirmed by the operator, and the use of the instrument is completed.

ELECTRIC STIMULATION INFUSION SYSTEM

[00162] As shown in FIG. 10 and 13, a system for drug infusion that contains electrostimulation elements is designated as 405. System 405 is configured to be used in various procedures, such as peripheral nerve block. The system 405 comprises a plurality of elements, which are the same elements as the elements described above in connection with the system indicated by reference numeral 5, or similar elements. Accordingly, elements in system 405, which are substantially similar to elements in system 5, have the same reference numbers.

[00163] The system 405 includes an injection unit 410 and a computer-controlled drug delivery tool 450, similar to the injection unit 10, and the execution unit 50 described above. The injection unit 410 includes an input needle 340 and is connected to the execution unit 450, which controls during use fluid flow to the injection unit. System 405 also includes one or more output devices that provide data to the specialist during the procedure, facilitating proper placement of the needle in the body of the subject.

[00164] The system 405 is configured to determine a location for the intrafascicular location of the needle. The system is also configured to deliver the therapeutic drug to the intrafascicular location of the needle. The drug may contain, inter alia, local anesthetic solutions, such as corticosteroids, hydroxyapatite, combined restorative drugs, sclerosing agents, and other drugs, which are usually injected into a fluid-filled tissue space for therapeutic purposes.

[00165] The intrafascicular position of the needle is a position in which the tip of the needle penetrates through the perineurium so that the tip of the needle is located inside the nerve bundle. The extrafascicular position of the needle is the position in which the needle is located anywhere outside the perineurium of the individual nerve bundle, which may contain external epineuria or even paraneuria, thus defined as completely extraneural.

[00166] Irreversible damage to the nerve can occur if the tip of the needle penetrates the nerve bundle and then fluid under hydrostatic pressure causes changes in the neural and vascular tissues in the nerve bundle. This is due to the fact that the outer layer of the nerve bundle is a protective layer of a relatively intractable rigid protective structure. It protects the main components of the nerve, i.e. axons that are tightly packed in a bundle. In other words, a bundle of nerves is a tightly packed formation with a thickened protective membrane. A bundle of nerves is not easily deformed when stretched or compressed. Thus, the tendency of the tissue to absorb fluid is extremely low and / or negligible. Penetration of the needle into the bundle of nerves does not necessarily cause permanent damage to the axon, but the combined effect of penetration of the needle and increased pressure inside the nerve bundle caused by fluid infusion into the bundle can lead to damage to the capillary bed. Furthermore, fluid pressure-induced strangulation of axon microcirculation prevents the immediate supply of nutrients after such physical trauma, leading to initial necrosis. The cumulative effect of necrosis leads to an inflammatory reaction in attempts to initiate wound healing from an initial pressure-induced injury that continues to expand or accumulate to potentially irreversible damage.

[00167] However, in some cases, intentional intrafasicular placement of the needle is desirable and necessary. Such cases include fatal phantom pain after amputation of the limb. In addition, hyperactive neural stimulation of a particular limb can sometimes lead to a removable pain and is another circumstance in which intentional intrafasicular needle placement and drug delivery are required. Accordingly, the system 405 and its use provides a method and apparatus for efficiently distinguishing between extrafascial and intrafascicular needle positions.

[00168] The injected fluid is absorbed through the tissue at various speeds. As a result, the pressure of the fluid changes. Thus, fluid pressure (or internal pressure related to tissue resistance pressure) is an indication and can be used to identify various types of tissue.

[00169] System 405 enables the attending physician to accurately identify fluid-filled tissue space while limiting the administration of drugs to non-target tissues. This applies to both diagnostic and therapeutic procedures. System 405 uses the pressure of the fluid flowing from the needle or catheter after placing the needle / catheter in the tissue to identify placement accuracy and monitor placement during injection or aspiration.

[00170] In particular, the system 405 includes one or more output devices for providing audible and / or visual feedback regarding the detected fluid pressure in the insertion needle. The operator uses visual feedback to guide during placement of the opening needle. As shown in FIG. 13, the first output device may be a screen of a display device, such as an LCD based display device, for displaying data assisting the operator. In addition, a second output device may also be provided. For example, the second output device may be a speaker for outputting an audio output signal.

[00171] The system 405 comprises an injection unit 410 that includes a syringe 18 and a sufficiently long length of flexible tubing 22 having a first end connected to the syringe and an insertion needle 340 connected to the second end. Thus, fluid from the syringe can be expelled through the tube 22 into the needle 24. The injection unit 410 also includes a pressure sensor for detecting the pressure of the fluid in the injection unit. The pressure sensor may be located in one of various places for measuring pressure, which correlates with the pressure of the fluid at the tip of the needle 340. In this case, the pressure sensor 20 is an integrated fluid pressure sensor attached to the syringe 18 between the syringe and the tube 22. Thus The pressure sensor 20 senses the pressure of the fluid when the fluid exits the syringe and enters the tube 22 to which the inlet needle 340 is connected.

[00172] The injection unit 410 may also comprise a reusable hand held unit 300 to which a needle is attached. As shown in FIG. 10, the insertion needle 340 is connected to the front end of the hand unit, and the tube 22 is connected to the rear end of the hand unit. The manual unit 300 may include means that assist the operator during the insertion process, as described in detail below. In addition, the manual unit 300 may be configured to provide electrical stimulation, as described in detail below.

[00173] The injection unit can be manually controlled to introduce fluid. However, in this case, the computer-controlled drug delivery system 450 controls the flow of fluid from the injection unit, as described in detail below. An output cable 21 connects the pressure sensor 20 to the drug delivery system 450, so that the drug delivery system can monitor and, if necessary, change the fluid flow from the syringe in response to data from the pressure sensor 20. The pressure sensor 20 can be connected by serial integration between the front end of the cylinder of the syringe 18 and the first end of the tube 22. One exemplary connection is the Luer connection of the pressure sensor 20 to the tip of the syringe. The connection may be a threaded connection and / or an irreversible threaded connection, such as a LuerLok type connection. According to another embodiment, the pressure transducer 20 may be permanently attached to the syringe by plastic welding or by chemical bonding, such as by means of adhesive. Thus, the instantaneous effective fluid pressure in the drug delivery line 22 is recognized and used in accordance with the instrument, thereby providing a close approximation to the actual instantaneous fluid pressure at the point or tip of the needle 340 and, thus, at a location in the patient’s body where the needle tip is located. An electronic pressure sensor 20 provides pressure data via electronic data cables that are connected directly to the central unit 50 to collect pressure measurement results.

[00174] As described above, the system 405 may include a fluid delivery system 50 for providing a controlled flow of drug to the injection unit 10. Preferably, the fluid delivery system is an automated system and in this case is a computer-controlled fluid delivery system, which is called executable block 450, which acts like the execution block 50 described above, unless otherwise specified in the description below.

ELECTRIC STIMULATION

[00175] The system 405 may also include an electrical stimulation element 334 that provides electrical nerve stimuli for the target tissue in the patient’s body. The electrical stimulation element is a conductive element connected to the hand-held unit 300. The electrical stimulation element is configured to provide an electric discharge of low intensity (ie, from about 0.15 mA to about 2.0 mA) and short duration (ie, pulses of duration approximately 0.1 ms to 1 ms). Electronic stimulating elements provide stimuli for a short time (i.e. for approximately 1-10 seconds).

[00176] The electrical stimulator may be an external element or an internal element. For example, in FIG. 10 and 13 show one embodiment that includes external electrical stimulants. A conductive element 334, such as a conductive cable connecting the hand unit 300 to the stimulus generator 335, so that electrical stimuli can be transmitted from the stimulus generator to the hand block. In turn, the manual unit is connected to an element configured to deliver an electric discharge to the tissue. For example, the needle 340 may be made of conductive material, and the hand unit may comprise a connection to the needle, providing a path for electric current from the conductive element and the needle. According to yet another embodiment, a conductive element, such as a wire, may extend along the needle, and the needle may be electrically isolated from the wire. For example, the needle may be made of an electrically insulating material. An example of an external electrical stimulating element is an insulated needle sold under the brand name "Stimuplex®", or also a needle catheter sold under the brand name "Contiplex®C" by B. Braun Medical Inc., Bethlehem, PA.

[00177] According to yet another embodiment, the system may use internal electrical stimuli. For example, the fluid introduced from the syringe may be an ionic solution that conducts electrical stimuli. The conductive element may be in contact with the fluid in an insulated needle. The needle may be made of various non-conductive materials. For example, the conductive element may extend along a fluid path at some point between the syringe 18 and the needle 340. For example, the conductive element may transfer electrical stimuli to the fluid at the rear end of the hand unit 300. If electrical stimuli are transmitted to tissue through the fluid, the needle 340 may be electrically isolated to minimize any leakage or loss of electrical charge through the side walls of the needle.

[00178] The electrical stimulation element is connected to an electric stimulus generator 335, which is an electrical source configured to transmit an electric discharge or pulse to a stimulating element. The stimulus generator may be located in the execution unit 450, as shown in FIG. 13. With this arrangement, the stimulus generator 335 is connected to the central processor of the execution unit so that the central processor provides electrical signals for controlling the operation of the stimulus generator. According to another embodiment, the stimulus generator may be a separate element having a separate energy source and a separate control.

[00179] The system 405 may also include a user-driven input device 470 that enables an operator to provide an input signal for controlling the system. The input device may be any of various devices, such as a manual or foot control device, which provides means for the operator to start and stop drug administration and change the drug input rate from one drug input rate to a second or third different predetermined input rate medicinal product. According to another embodiment, the input device may be a button, touch screen, mouse, keyboard, or microphone to issue audio input commands. In addition, the system may comprise a plurality of input devices to enable the operator to enter a plurality of input data for various steps of the procedure. For example, the system may comprise a first input device, such as a foot pedal, that controls the flow of fluid through the device. The activation of the foot pedal controller (i.e., pressing the switch) transmits a signal to the central processor of the execution unit, which in turn transmits a signal to the motor to actuate it so that fluid flows from the syringe to the needle 340 when the pedal is activated. According to yet another embodiment, depressing the foot pedal at the first time may control the start signal to start the flow of fluid, and the fluid may continue to flow until the operator depresses the foot pedal again. Thus, the second press acts as a stop signal to stop the flow of fluid. In addition, the system may include a second input device, such as a touch screen, so that when applying electrical stimulation to the patient, the operator can enter an indication as to whether a muscle convulsion has been detected or the patient has noticed a corresponding sensation. In addition, the primary or secondary input device may be controlled by a button, such as a button 325 on a hand unit. Activation of the control button 325 may transmit a signal to the central processor to provide feedback during the procedure.

[00180] As described above, a fluid pressure is used to control the operation of the system 5. Similarly, a fluid pressure is used to control the operation of the peripheral nerve block system 405. For example, system 405 may provide a signal to the operator if the fluid pressure exceeds a threshold value, thereby indicating that the needle may be positioned intrafasculally. As described above, there are various methods for calculating the pressure of the fluid at the outlet of the needle.

METHOD FOR WORKING THE SYSTEM CONTAINING ELECTRIC STIMULATION

[00181] An exemplary method for administering an epidural injection to a patient using the system described above is described below. It should be understood that the present system is not limited to use only in the procedures of peripheral nerve blockade. Accordingly, it should be understood that the principles and methods described below can be easily implemented for injection into tissues and anatomical areas in various applications and procedures.

[00182] The system can be used to determine if a needle is located in a bundle of nerves (ie, whether it is located intrafasculally). The system performs the determination based on the union of several variables. First, if the needle pierced the endoneuria, the fluid pressure will be very high, since the axons are tightly packed in the endoneuria. In addition, if the needle pierces the endoneuria, the operator is likely to observe a noticeable reaction to electrical stimulation applied to the patient in or near the tip of the needle. Thus, if the operator receives a notification of high fluid pressure and then applies electrical stimulation and notices a reaction, it is likely that the needle is intrafasicular and thus should be repositioned. So, the system can work as follows.

[00183] As shown in FIG. 14, in step 500, the operator selects procedure parameters, such as an upper threshold value and / or fluid flow rate, and / or needle advancement speed. For example, an operator may set an upper threshold pressure, such as 300 mmHg. (40.0 kPa). According to yet another embodiment, an upper threshold value may be set in the system when the operator selects the type of procedure for which the system should be used. Similarly, the operator can select the flow rate of the fluid through the needle, or the flow rate can be set automatically when the operator selects the type of procedure. In addition, the operator can choose the duration of electrical stimulation of the nerve during its use. After selecting the procedure parameters, the operator provides an indication that the procedure should be started. For example, the operator may press the "Start" button on the execution unit.

[00184] At step 510, the operator advances the needle into the patient's body. As described above, the needle can be advanced at any of various injection rates, such as 3-10 mm / sec. Preferably, the needle is driven at a substantially constant speed. Accordingly, at step 510, the operator can insert the needle at a constant speed, guided by indicator 315, as described above.

[00185] In step 515, while the operator advances the needle, the system continuously determines the feedback pressure in the needle and provides feedback in visual or audio form relative to the specific pressure. The visual signal changes when the detected pressure changes.

[00186] At step 520, the operator continues to advance the needle until the system provides a signal indicating that the fluid pressure has exceeded the upper threshold value.

[00187] At step 525, it is determined that the fluid pressure exceeds the upper threshold value, so that the system provides a warning signal in the form of an audible, visual, and / or tactile signal. In response to a signal indicating that the fluid pressure has exceeded the upper threshold value, the operator stops the advancement of the needle. In addition, the execution unit can stop the engine to stop the flow of fluid to the needle.

[00188] At step 530, an electrical nerve stimulation signal is applied to or near the tip of the needle 340. For example, as described above, electrical nerve stimulation can be transmitted to a conductive element located adjacent to the tip of the needle. Electrical nerve stimulation can be provided automatically by the system in response to fluid pressure exceeding the upper threshold value. For example, when the fluid pressure exceeds an upper threshold value, the system provides an appropriate signal to the operator. In addition, at that moment or after a short delay, such as 1-3 seconds, the system can perform electrical stimulation of the nerve. In yet another embodiment, an operator can apply electrical stimuli by providing an introductory prompt, such as a button press or an oral command. In response to a prompt from the operator, electrical nerve stimulation is applied to the patient. In other words, when the pressure of the fluid exceeds the upper threshold value, the system prompts the operator to apply an electric discharge, and the operator applies an electric discharge in response to this signal.

[00189] At step 540, the operator monitors the patient for the determination of any clinically observed reaction, such as muscle convulsion. The operator then provides input into the system indicating whether the observed reaction has been detected. For example, the operator may press the first button if he has noticed a convulsion, or the operator may press the second button if he has not observed a convulsion. If the operator has confirmed the observed reaction, the method proceeds to step 545. If the operator does not confirm the observed reaction, the method proceeds to step 560.

[00190] At block 560, the system provides an alert to the operator. The notification may be visual, audible and / or tactile. The alert alerts the operator that the needle may be positioned intrafasculally. For example, the system can provide an audible warning sound alert, such as the word “Warning,” while providing a flash of light on the hand-held unit.

[00191] At step 550, the operator retrieves the needle and repeats its introduction in an attempt to place the needle in the target area without piercing the perineurium. Thus, the method restarts at step 510.

[00192] If there is no observed reaction at step 540, the method proceeds to step 560. At step 560, the system provides a signal to the operator indicating that the needle is properly positioned for injection (ie, the tip of the needle is extrafascicular). For example, the execution unit 50 may provide an audio signal, such as an audio reproduction of the word "Continue", or to provide a visual signal, such as the word "Continue", on the screen of the display device of the execution unit or the hand unit.

[00193] In step 565, the fluid velocity increases to a second velocity that is higher than the first velocity. The operator can enter a preliminary value that can be observed so that the operator can detect that the needle is properly positioned. After confirmation of placement, the operator can administer a bolus (single dose) of fluid to anesthetize the patient. In yet another embodiment, the operator can enter a fluid bolus without entering a first value to verify needle placement. In any case, the fluid is introduced at step 565 at a higher speed than the previous low speed. According to another embodiment, in response to an indication that the upper pressure limit has been exceeded and an indication that a reaction is not observed in response to electrical stimulation of the nerve, the execution unit can automatically increase flow, for example, by increasing engine speed.

[00194] Another advantage of the proposed device and method is the objective nature of the pressure measured by a computer-controlled drug delivery device that is monitored during all phases of the injection process. Thus, the attending physician no longer relies on the subjective nature of “sensation”, but rather is provided with objective information about the absolute values ​​during each phase of this risky method. Each phase of the method is improved due to the possibility of objective monitoring of pressure on a continuous basis.

[00195] It should be understood that a value of 300 mmHg (40.0 kPa) as the maximum target pressure to stop the flow of fluid is only an example, and that at the discretion of the attending physician, a lower or higher target pressure can be selected. The methods described herein are equally applicable to human and animal tissues.

[00196] Those skilled in the art will understand that the above described embodiments may be implemented with changes or modifications without departing from the broad inventive concepts of the present invention. For example, in the above description, a system is described in the context of providing fluid infusion. However, it should be understood that the system can be used to place the needle when aspirating tissue-filled fluid. In particular, an injection device can be used to aspirate a fluid-filled tissue space after determining the identification of said fluid-filled space. Aspiration can be used to extract a sample of tissue or extracellular fluid (i.e. cerebrospinal fluid, intra-articular fluid, blood, etc.) or can be used to determine the proper placement of an injection needle. During the suction procedure, the “inlet pressure” is measured in the same manner as the pressure in the tissue-filled fluid space, which is characterized by a pressure drop. Similarly, a false pressure drop is also identified using an aspiration procedure, since the content of the internal tissue structure (i.e., cysts) drains quickly and the inlet pressure rises above the threshold inlet pressure.

[00197] Thus, it should be understood that the present invention is not limited to the specific embodiments described in this application, but includes all changes and modifications that are within the scope of protection and the principle of the present invention defined by the appended claims.