Local anesthetic and delivery injection unit with automated rate control

Description of the invention

The present invention relates to an injection device, particularly adapted for the performance of dental and medical procedures, wherein the rate of administration of the anesthetic is controlled and automatically maintained until reset or changed by an operator.

The administered local anesthetic eliminates the excruciating pain that is felt during medical procedures, dental extractions, drilling and the like, but the doctor or dentist's patient still experiences pain resulting from subcutaneous injections of anesthetics into the body tissues.

It has been found that over 50% of adult patients are usually worried about having injections, and even more of them are worried about injections into the mouth during dental procedures.

Therefore, it is desirable to provide a system for administering medical and dental anesthetic injections that substantially eliminates the pain that a patient suffers from while administering anesthetic injections into the oral cavity or into other body tissues.

In US Patent No. 6,022,337, a local anesthetic system is generally described which eliminates the pain sensation from the nerve clusters receiving signals from the teeth and surrounding dental structures in the injection area and during the puncture before the pain is felt by the patient. The system includes a drive unit for selectively delivering the anesthetic through a controlled handpiece unit that supports the needle as it penetrates the tissue. The operation of the drive unit is selectively controlled so that different amounts of anesthetic are delivered through the needle depending on whether the physician is also penetrating the tissue, or otherwise attaining a tissue location where nerve shutdown is required.

The system uses a linear actuator to deliver a controlled amount of anesthetic from a reservoir that is built into the drive unit. The drive unit can be controlled by a foot pedal that is selectively released to deliver anesthetic through the handpiece unit.

The system is designed to use a local anesthetic reservoir and a variety of needle sizes. The drive unit of the system includes a motor and an on-board microprocessor to control the flow of anesthetic. The drive unit using the technology described in US Patent Nos. 4,747,824 and 5,180,371, enables the delivery of an anesthetic solution at a constant pressure and volume depending on the variability of tissue resistance. During insertion of the needle tip, the system delivers a small amount of anesthetic that precedes the needle when injected into dental tissue, thereby creating an anesthetic pathway. The combination of an anesthetic pathway and controlled pressure and volume (flow rate) allows for an effective and painless injection. The system further comprises a foot pedal operatively connected to a compressed air hose which in turn is connected to a pressure sensor. While the system is running, the pressure change signal from the foot pedal is detected by the pressure sensor. The pressure sensor then generates the appropriate control signal to control the flow of the anesthetic. In a preferred embodiment, when the foot pedal is lightly or partially depressed, the system is operated at a slow speed. When the foot pedal is significantly or fully depressed, the system runs at a higher speed.

The system can be programmed to operate at different flow rates, not limited to two speeds.

When the system works satisfactorily, some physicians or dentists may not be completely satisfied with the fact that it requires holding the pedal in a certain position for an extended period of time.

In addition, US Patent No. 5,690,618 describes an electronic syringe used for the administration of an anesthetic and similar injections or for the aspiration of a fluid. The electronic syringe is especially useful in dental applications where a precise level of manual control is required. The housing of the syringe is a compact pen-type arrangement that can be clamped between the middle and forefinger of the practitioner's hand, allowing the thumb to be operated freely. A motorized operation is envisaged, preferably wireless control, with speed control and data acquisition, so that injection can be carried out into the patient's body in a consistent, painless manner, without causing anxiety to the patient. When connected to a processing device, the collection feature

The data entry is useful for updating the patient database with the injection of anesthetic and similar injections in order to keep the record.

An injection device comprising a treatment fluid supply unit with one of two first or second operating speeds, a microprocessor for generating control signals for the treatment fluid supply unit and an operator operated control element for selecting one of said first or second operating speeds, according to the invention is characterized by with this, that a control element connected to the microprocessor is controlled by the microprocessor to maintain the selected speed of the treatment fluid supply unit after the control is released by the operator, the control element having at least two speed selection positions of the treatment fluid supply unit and a neutral position, the control element being it is returned to the neutral position when released by the operator.

It is preferred that the device is additionally provided with an operator-actuated auto-control removal switch, wherein the treatment fluid supply unit is disabled by the processor upon actuation of the auto-control removal switch.

It is preferred that the microprocessor is connected to an operating mode selector switch, wherein the selected speed is maintained in the first mode of operation, as well as in the second mode of operation, wherein the treatment fluid supply unit is actuated by the microprocessor to maintain a speed associated with the position of the control element.

In another embodiment, an injection device, in particular for injecting a medicated fluid into a patient under the control of a clinician, which includes a handle to be held by the clinician when administering the fluid, a pump for selectively delivering fluid to the handle, a motor for driving the pump at a selected operating speed according to a control signal. a control member operated by the clinician for selecting the speed of operation of the device according to the invention is characterized by that the control element has a first position associated with a selected rate of operation and a second position and is connected to a microprocessor whose output of the generated control signal is active when the control element is released and actuated by the clinician, the rate of treatment fluid selected by the microprocessor being associated with each position of the control element , also for automatic control mode, where the selected speed is held after the control is returned to the neutral position.

It is preferred that an automatic control removal switch actuated by the clinician is connected to the microprocessor, and a new control signal is generated at the output of the microprocessor for the treatment fluid delivery device in the active state of the automatic control removal switch.

The invention provides a local anesthetic injection device that can be used for all known medical and dental injection procedures and has an improved automatic mode of operation. This device reduces the effort of the dentist or other physician in the event of an extended injection session. The injection device has an automatic mode of operation which allows the physician, dentist or other medical operator to pay attention to other details and only allows attention to the system when it is required to change its operating mode. The developed dental system for the injection of anesthetics increases the precision and accuracy of the anesthetic delivery.

Briefly, the injection device of the invention comprises an electrically operated pump, a handle terminating in a needle through which a medicament is injected, and a foot switch or other similar control device (i.e., a manual control device) used to actuate the pump regulator. The control device may have several control positions. In one embodiment, the control device has three positions: OFF - OFF, SPEED 1, and SPEED 2. The pump is turned OFF at RATE 1, drug is delivered at the first flow rate, and at RATE 2, the pain reliever is delivered at the second, higher flow rate. Alternatively, the control device is arranged to have a plurality of discrete positions or to have a stepless adjustment of the setpoint between the RATE 1 and RATE 2 positions, the feed rate being smoothly variable between the upper and lower limit of the feed rate. Preferably, the control device is a spring device or is otherwise driven, therefore, when in the SPEED 1 or SPEED 2 position, it is released and changes automatically to the OFF position. Importantly, the pump control device according to the invention has several operating modes.

PL 199 147 B1

In one operating mode, which is defined by the manual mode, the pump control device monitors the position of the control device continuously and controls the pump in a manner corresponding to the position of the control device, so that when the control device is in the SPEED 1 position, the pump runs with speed (SPEED 1), in the SPEED 2 position, the pump runs at the second speed (SPEED 2) and the fluid is being delivered at the corresponding speed. If, on the other hand, the control device is in the OFF position, the pump motor is turned off or is in automatic priming mode. The second operating mode is the so-called automatic mode. In this operating mode, the pump controller works in a manner similar to that of a car's automatic cruise control. In particular, in automatic mode, when the control device is released, the pump controller maintains the current operating parameters of the pump until a separate control device, such as a manual safety switch resetting the device by the automatic controller, is activated to change the operating mode of the pump. The separate control device includes a separate button on the handle, on the control device or on the pedal switch. Such an effect can be achieved through a program. There is a "time slot" in which removing the foot from the foot control activates automatic mode. The "time slot" can be defined using the software and can be activated by removing the foot control.

The present invention is also applicable to other medical and dental devices such as an ultrasonic hammer, polishers, and other rotating and electronic instruments operated by a clinician at a controlled flow rate or work rate.

In a variant of the invention, the injection device is adapted to inject a medicated fluid into a patient under the control of a clinician. The device comprises a handle adapted to be held by a clinician delivering the fluid, a pump adapted to selectively deliver fluid to the handle, a motor adapted to drive the pump at a selected speed according to a control signal, a control operable by the clinician to select a speed of operation. The control element has a first position corresponding to the selected operating speed and a second position. Connected to the control is a microprocessor adapted to generate a control signal subsequent to actuation of the control and release by a clinician to generate the control signal.

The subject of the invention is illustrated in an exemplary embodiment in the drawing, in which fig. 1 shows schematically the injection device, fig. 2 - block diagram of the device of fig. 1, in manual operation of the injection device, fig. 3 - flowchart showing the operation of the device Figs. 1 and 2 in manual mode; Fig. 4 is a flowchart showing the operation of the injection device of Figs. 1 and 2 in automatic mode, and Fig. 5 shows the injection device of Figures 1 and 2 in an alternating mode of operation.

Generally shown in Figures 1 and 2, the injection device is used for injecting or otherwise introducing (or alternatively aspirating) fluid into a patient's body. The device comprises a housing 102 with a plurality of indicators 104 and the control buttons of the switches 106 or other user-selectable input means allowing the input of user-selectable data and commands. One type of control buttons on the switches 106 is a rotatable knob 106A with a plurality of possible positions for selecting a mode of operation.

The fluid reservoir containing drugs, anesthetics, or other fluid is housed within or otherwise connected to housing 102. The fluid may be used by a physician or other healthcare provider to perform medical or dental procedures on a patient.

The injection device further includes an elongated tube 108 with one end attached to the housing 102 and the other end attached to the handle 110. The handle 110 includes a syringe with a needle 112.

The injection device also includes a foot pedal 114 connected to housing 102 by an air line 116. The foot pedal 114 includes a primary control 118 that has three or more positions, and preferably comprises a switch with at least three positions. A second control 120 is also located on the foot pedal 114.

Fig. 2 is a block diagram of the electrical components of the injection device. The device includes a microprocessor 150 that is connected to programmable memory 152 and control switches 106 for providing control signals. Pneumatic conduit 116 is connected to a pressure sensor 154 which produces an electrical signal corresponding to the position

The switch 118 of the foot pedal 114. The microprocessor 150 provides visual indications and communicates information to the operator via the indicators 104, and further signals the information by voice and gives verbal instructions through the loudspeaker 156.

The primary function of microprocessor 150 is to control motor 158 receiving control commands from microprocessor 150. In response to a control command, motor 158 actuates pump 160 which is connected to a fluid source or reservoir 162 and can supply fluid from the reservoir to a conduit constituting the elongated tube 108 or in a line. in reverse mode, aspirate fluid from the elongation tube 108 into the fluid reservoir 162. Pump 160 and fluid reservoir 162 are embodied in many different forms. For example, pump 160 and fluid reservoir 162 are preferably formed as a syringe with a reciprocating plunger driven by a rod connected to motor 158.

The components shown in Fig. 2 are preferably housed in housing 102. Alternatively, at least some components such as motor 158, fluid reservoir 162, and pump 160 are preferably housed in handle 110. In this case, the elongated tube 108 is replaced by an electrical connector.

The injection device can operate in several operating modes. The mode of operation is determined by the position of the knob of the manually operated switch 106B, which resets the device by an automatic controller. In one position of the knob of this switch 106B, the injection device operates in the same way as a known injection device. This mode of operation of the injection device according to the invention is defined as manual or semi-automatic. The device then operates according to the control signals from the clinician. This mode of operation will be described on the basis of the flowchart of Fig. 3. In step 200, initialization of the device takes place. This step includes entering a plurality of various operating parameters into programmable memory 152, filling reservoir 162 with appropriate fluid, and rinsing the elongated tubing 108 and the syringe with needle 112. When the clinician is ready to administer the injection, he presses a button or sets the knob of switch 106B to indicate the start of operation (step 202). Once operation has commenced, the microprocessor 150 checks the position of the foot pedal 104 actuating the switch 118 (step 204). If the switch is active, as determined in step 206, then in step 208, the microprocessor 150 obtains the current position of the foot pedal power control 118.

For example, the switch is in the OFF position, position 1 or position 2.

In step 210 a check is made to determine if the switch is in position 1. If so, in step 212 the microprocessor 150 sets motor 158 to run at first speed. The microprocessor 150 then returns to step 208 and reads the new position of the foot switch control 118.

If in step 210 it is determined that the switch 118 is not in position 1, then in step 216 it is checked to see if that control 118 is in position 2. If so, in step 216, the microprocessor sets the motor 158 to work. for second speed operation. In an alternate embodiment, the speed of the motor 158 in these steps may be set to be between the upper and lower limits. In this embodiment, the switch 118 must be able to be variable between positions 1 and 2.

If control switch 118 is not in position 2, then in step 218, microprocessor 150 checks to see if control switch 118 is in the off position. If so, in step 220, motor 158 is stopped. In an alternate embodiment, under certain conditions, in step 220 for a short period of time to induce a suction effect, the motor 158 may be operated in a reversible mode. Moreover, it is possible to provide a separate switch (not shown) that could cause the motor to reverse. In either case, in the mode shown in FIG. 3, the microprocessor 150 checks the position of the control switch 118 and adjusts the operation of the motor 158 accordingly.

As shown, in some cases this mode of operation may not be satisfactory. Therefore, engine 158 may also be operated in full cruise control mode. The mode is selected by changing the position of the mode selector switch 106A. In this mode, the injection device operates similarly to the mode of operation shown in Fig. 3, with some exceptions. Preferably, in step 202A (Fig. 4) when the device starts to operate, the clinician is informed about the selected mode of operation, i.e. in this case the automatic mode of operation (the so-called cruise control mode). This step is performed by generating a voice message

PL 199 147 B1 transmitted by loudspeaker 156, conveying a visual message presented on one of the displays, a combination of verbal / visual messages, or by other similar means of communication.

In addition, upon starting the engine in one of the desired modes of operation, the microprocessor 150 checks to see if the override switch 106B is actuated (step 222).

The switch is preferably located on the housing 102, or on the pedal 114 of the foot switch, and constitutes the second control 120, or on the hand switch and the like. If in step 224 it is determined that the switch has not been turned on, then in step 226 the previous speed of motor 158 is maintained.

The microprocessor 150 continues to check the position of the override switch (106B) at regular intervals and at these intervals, the motor speed 158 is held at the previously selected value. Since the position of the pedal of the switch constituting the first control element 118 is not checked during steps 222, 224, 226, the clinician may release the switch pedal after step 212, which allows the switch to return to the neutral or off position.

After the manual override switch 106B is turned on, which is preferably a momentary switch, the clinician may use the first control pedal switch 118 to generate a new control signal for the motor (i.e., speed 1, speed 2, shutdown).

Alternatively, as shown in FIG. 5, the function of the manual override switch 106B may be performed by memory software 152. In this embodiment, once the motor speed is determined (step 212 or 216), the speed is confirmed in step 222A. This is a signal (either visual, audible, or both) given to the clinician to indicate what the current speed of the engine is. This signal causes the clinician to release the switch pedal and allow the clinician to return to the neutral or off position. Then, in step 223, the position of the switch pedal is checked. In step 224, a check is made to see if the switch pedal has been activated or has been moved from the off position. If the switch pedal is still in the off position, in step 226 the engine speed is kept unchanged. If the switch pedal has been reactivated, microprocessor 150 returns to step 204.

In the illustrated embodiment, a particular type of injection device is described which is controlled by a clinician via a multi-position foot pedal of the controller. Of course, many other types of devices or controls could be used to achieve a similar solution. For example, switches or other controls for controlling fluid dispensing may be located on the housing or the handpiece.