Method for anchoring medical device between tissues

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

Roughly speaking, the present invention relates to a remote communication type medical device. More specifically, the present invention relates to a novel telecommunications-type medical device useful in various medical applications including measurement of parameters in a patient's body, particularly in an organ. Applications of the present invention include, for example, implantable intracardiac pressure devices, associated novel components and novel uses thereof.

【0002】

[Conventional technology]

Medical sensors that can be implanted in a patient's body are generally known. An example of a portable sensor is disclosed in US Pat. No. 4,815,469 (Cohen et al.), Which is part of this application by reference. Disclosed in this US patent is a implantable sensor that determines the oxygen content of blood. The sensor has a small composite circuit, which has a light emitting diode means, a phototransistor means, and a substrate in which the light emitting diode means and the phototransistor means are connected so as to form a desired circuit form. .. This composite circuit is hermetically sealed inside a cylindrical body made of a glass-like material that is almost transparent to light. Feedthrough terminals provide a means for electrical connection to composite circuits. The light emitting diode means is driven by a stepped current pulse. The purpose of this sensor is to detect the reflective properties of body fluids such as blood for spectroscopic analysis. In one embodiment, the sensor is embedded in a double-cavity pacemaker lead, placed near the electrode on the distal end of the lead, and when the lead is inserted inside the heart, the sensor It is designed to be placed inside the heart. This allows the detected oxygen content in the blood inside the heart to be a physiological parameter that can be used to control the pacemaker's beating interval in response to the content.

【0003】

U.S. Pat. No. 5,353,800 (Pahndorf et al.) Discloses implantable pressure sensor leads. This lead has a hollow needle suitable for being screwed into the patient's heart. Power is supplied to this pressure sensor via the conductor of the sensor.

【0004】

Permanent placement of such sensors may be required. An example is disclosed in US Pat. No. 5,404,877 (Nolan et al.), Which is part of this application by reference. Reedless implantable cardiac arrhythmia alarms have been disclosed. This alarm constantly evaluates the patient's cardiac function, distinguishes between normal and abnormal heart activity, and generates a patient alarm signal when an abnormal condition is detected. This alarm can detect the impedance of the heart, respiratory movements and movements of the patient, and when these measurements indicate the occurrence of cardiac arrhythmia, these measurements generate alarm signals. It is important to note that the sensor has an antenna system. This antenna system has a coil dielectric that creates an electromagnetic field within the tissue to detect changes in impedance associated with biological phenomena. For example, the dimensions of the dielectric are preselected to match the dimensions of the tissue or structure being measured.

【0005】

Further, a portable device that transmits / receives data to / from an external device using remote communication is known. An example of such a device is the device disclosed in US Pat. No. 6,021,352 (Christopherson et al.). The device utilizes a pressure sensor as a transducer to detect the patient's respiratory effort. Respiratory waveform information is received from the transducer into a implantable pulse generator (IPG) / simulator, which performs a simulation synchronized with exhalation.

【0006】

Other telecommunications portable devices are disclosed in US Pat. No. 5,999,857 (Weijand et al.). This document discloses a remote communication system, which is used with portable devices such as cardiac pacemakers to provide two-way remote communication between an implanted device and an external programmer. To enable. The system uses oscillators and coding circuits for synchronous transmission of data codes, making the data codes carriers of distant communications. The system includes a circuit for high-density data coding of sinusoidal codes and uses a combination of BPSK, FSK and ASK coding for high-density data coding. Transmitter embodiments as well as modulation and demodulation circuits for both implanted devices and external programmers are also disclosed. It is important to note that the implanted device is equipped with its own power source in the form of a battery to power all of its internal circuits and components.

【0007】

[Problems to be Solved by the Invention]

Also, it is important to note that, at present, telecommunications that achieves high efficiency due to the components and their ease of use while providing highly accurate information about the measured parameters in the patient's body. There is no medical system.

【0008】

The present invention is a novel telecommunications medical system used for various medical applications such as monitoring medical conditions or measuring parameters in a patient's body for various types of organs in terms of tissue and its function. I will provide a.

【0009】

[Means for solving problems]

The present invention is a telecommunications-type medical system that is implanted in the body of a patient and includes a telecommunications-type medical sensor for measuring parameters in the body. The sensor comprises a housing and a thin film located at one end of the housing, the thin film being deformable according to the parameters. Inside the housing is a microprocessor in the form of a microchip, which operatively communicates with the thin film to transmit signals indicating the parameters.

【0010】

A signal reading and charging device can be placed outside the patient's body, which communicates with the sensor. The signal reading and charging device has a casing and a circuit inside the casing. This circuit has a logical control unit and a processing unit operatively connected to the logical control unit. The logic control unit receives the signal transmitted from the sensor via the deep detector. In addition, the logic control unit transmits a power supply signal to the sensor via a sine wave driver in order to power the sensor remotely. The feeding signal is a sinusoidal signal of about 4 MHz to 6 MHz. The processing unit has an algorithm that converts the transmitted signal received from the sensor into measurement parameters. Further, the signal reading / charging device has a power supply unit operatively connected to the circuit and a power switch for turning the device on and off.

【0011】

The signal reading / charging device further includes an antenna coil for transmitting a power feeding signal to the sensor and receiving a digital signal to be transmitted from the sensor. This antenna coil causes inductive coupling with the sensor. Further, the signal reading / charging device has a display device for displaying the measured parameters, and this display device is an LCD screen.

【0012】

A microprocessor in the form of a microchip comprises an array of photoelectric cells, the photoelectric cells being arranged in a staggered row. The array also has reference photoelectric cells located at one end of the array. A light emitting diode (LED) sends light to the photoelectric cell and the reference photoelectric cell.

【0013】

The sensor further comprises a shutter that is coupled to the thin film and can move between the photoelectric cell and the LED as the thin film deforms. The sensor is configured so that the reference photoelectric cell receives the light emitted from the LED without being obscured by the shutter.

【0014】

Further, the microchip includes a plurality of comparators operatively connected to the photoelectric cell and a buffer for storing and sending a digital signal operatively connected to the comparator. In addition, the sensor comprises a coiled antenna operatively connected to the microchip, which antenna is located outside the housing. Alternatively, the antenna is located inside the housing. Preferably, the antenna coil is formed of wires containing silver and platinum iridium. In addition, the antenna has 20 to 25 twists.

【0015】

The sensor according to the present invention further comprises a plurality of anchoring legs elastically attached to the housing to anchor the sensor to the tissue. Further, optionally, the housing has a notch on its outer surface for ease of deployment. Further, optionally, the housing has a circumferential groove in the notch for ease of deployment.

【0016】

In another embodiment of the sensor, the housing further has a tapered end and a penetration end provided at the tapered end. The tapered end also has a spiral streak for screwing the sensor housing directly into the tissue. Another embodiment has a plurality of tissue penetrating claws at the tapered ends for the sensor housing to be anchored directly within the tissue.

【0017】

The present invention also has a method for remotely measuring parameters in a patient's body. This method comprises the step of providing a remote communication type medical sensor. This telecommunications-type medical sensor has a housing, a thin film that is placed at one end of the housing and can be deformed according to parameters, and a thin film that is placed inside the housing and is operatively connected to the thin film to transmit signals indicating parameters. It is equipped with a microchip for housing. The sensor is implanted somewhere inside the patient's body and the parameters are measured remotely from outside the patient's body by a signal reading and charging device. The method also includes remote feeding from outside the patient's body by means of a signal reading and charging device. Then, the measured parameters are displayed on the display device of the signal reading / charging device.

【0018】

In addition, the method according to the present invention includes a method for remotely measuring parameters in the heart of a patient. This method has a step of visualizing the heart by using transesophageal ultrasound imaging and a step of recognizing the implantation site in the heart. An opening is formed at the tissue implantation site and a sensor is provided. The sensor consists of a housing, a thin film that is placed at one end of the housing and can be deformed according to parameters, and a micro that is placed inside the housing and is operatively connected to the thin film to transmit a signal indicating the parameters. Equipped with a chip. The sensor is placed in the opening and the parameters are measured remotely from outside the patient's body based on the signal transmitted by the sensor.

【0019】

The method also comprises remotely feeding the sensor from outside the patient's body with a signal reading and charging device and displaying the measured parameters. Parameter measurement is performed multiple times per second by the signal reading and charging device.

【0020】

According to the present invention, the sensor is placed in the space of the heart using a partition wall such as a foramen ovale as an implantation site. Alternatively, the sensor may be placed at other anatomical sites in the heart and other organs and tissues.

【0021】

One parameter measured by the systems and methods according to the invention is the hemodynamic pressure in the space of the heart. Therefore, the method according to the present invention further includes performing parameter measurement 10 to 20 times per second.

【0022】

In addition, this method involves forming an opening in the tissue with a needle. In one embodiment of the invention, the sensor has multiple anchoring legs to anchor the sensor to the tissue. In addition, the sensor is coated with a non-thrombus agent to prevent the formation of blood clots inside the heart in response to the implantation of the sensor.

【0023】

Another embodiment of the method according to the invention has a method of remotely measuring parameters in the patient's heart. This method has a step of visualizing the heart using transesophageal ultrasound imaging and a step of recognizing the implantation site in the heart. A housing is provided, a thin film located at one end of the housing that can be deformed according to parameters, and a sensor having a tapered tip and a penetrating end located at the other end of the housing. In addition, the sensor is located inside the housing, operably communicated to the thin film, and comprises a microchip for transmitting a signal indicating a parameter. The sensor is embedded in place by the penetrating end and tapered tip of the sensor. The parameters are measured remotely from outside the patient's body based on the signal transmitted by the sensor. In addition, the sensor is powered remotely from outside the patient's body. A signal reading and charging device is used outside the patient's body for parameter measurement, feeding the sensor and displaying the measured parameters. Therefore, the parameter measurement is performed a plurality of times per second by the signal reading / charging device.

【0024】

The sensor is placed in the space of the heart using a partition wall such as the foramen ovale as an implantation site. According to the systems and methods according to the invention, one parameter measured is the hemodynamic pressure in the space of the heart. According to the present invention, for monitoring blood pressure, for example, 10 to 20 parameter measurements are performed per second.

【0025】

Alternatively, the sensor has a spiral streak at its tapered tip, and the sensor is anchored to the tissue by screwing the tapered tip directly into the tissue at the implantation site. Alternatively, the sensor has a plurality of tissue penetrating claws at the tapered tip and is anchored to the tissue by the tissue penetrating claws.

【0026】

The invention also includes implantable medical devices such as remote controlled sensors with housings having proximal and distal ends. The housing has a longitudinal axis. Also, the implantable medical device has a first set of fixing members operably connected to said proximal end of the housing. A second set of fixing members is operably connected to the distal end of the housing. The first set of fixing members and the second set of fixing members are movable between the closed position and the deployed position. The closed position is a position where the first set of fixing members and the second set of fixing members are arranged substantially parallel to the axis in the longitudinal direction of the housing. The unfolding position is a position where the first set of fixing members and the second set of fixing members are arranged substantially at right angles to the axis in the longitudinal direction of the housing. Each of the first set of fixing members and the second set of fixing members has a ring member. Each of the ring members has a tissue engaging surface.

【0027】

The first set of fixing members and the second set of fixing members have a plurality of fixing members. Preferably, the first set of fixing members and the second set of fixing members are arranged in pairs at both the proximal and distal ends of the housing.

【0028】

The ring member has a nickel titanium alloy, for example, a shape memory alloy such as nitinol (NiTi). An elastic member such as a bias spring is connected to the housing and the ring member in order to elastically deflect the ring member to the housing. As another example, both the housing and the ring member are made from a shape memory alloy such as nitinol, which allows the ring member to be moved between the closed and unfolded positions without the need for a bias spring. ..

【0029】

The closed and unfolded positions span the desired effective range, but the closed positions of the first and second sets of fixing members are in the range of 0 ° to 30 ° from the longitudinal axis of the housing. is there. The deployment position of the first set of fixing members and the second set is in the range of approximately 40 ° to 90 ° from the longitudinal axis of the housing.

【0030】

In some embodiments according to the invention, the ring member is a complete loop. In another embodiment of the invention, the ring member is an incomplete loop. In one embodiment of the invention, the first set of fixing members and the second set of fixing member ring members have a concave contour.

【0031】

The invention further comprises a method of implanting a medical device between tissues, comprising the step of providing a catheter having a body and a distal end. The catheter has a implantable medical device having a housing with proximal and distal ends and a longitudinal axis. Further implantable medical devices include a first set of fixing members operably connected to the proximal end of the housing and a second set operably connected to the distal end of the housing. It has a fixing member. The first set of fixing members and the second set of fixing members are movable between the closed position and the deployed position. The closed position is a position where the first set of fixing members and the second set of fixing members are arranged substantially parallel to the axis in the longitudinal direction of the housing. The unfolding position is a position where the first set of fixing members and the second set of fixing members are arranged substantially at right angles to the axis in the longitudinal direction of the housing. Each of the first set of fixing members and the second set of fixing members has a ring member, and each of the ring members has a tissue engaging surface.

【0032】

The method includes inserting the distal end of the catheter into tissue and moving at least a portion of the medical device from the distal end of the catheter. At this point, the first set of fixing members is moved from the closed position to the deployed position. The method further comprises an engagement step between one side of the tissue and the tissue engaging surface of each ring member of the first set of fixing members. In addition, the medical device is completely moved from the distal end of the catheter and the second set of fixation members is moved from the closed position to the deployed position. At this point, the other side of the tissue (opposite side of the tissue) engages the tissue engaging surface of each ring member of the second set of fixing members.

【0033】

In carrying out the methods of the invention, implantable medical devices are moved from the distal end of the catheter through the use of a deployment mechanism associated with the catheter. In addition, medical devices can be deployed among various tissues, such as tissues in the heart. For example, when deployed within heart tissue, the method according to the invention can be used in the septum of the heart between the left and right atrium. The invention will be more fully understood from the detailed description and drawings of preferred embodiments of the invention below.

【0034】

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention relates to a novel telecommunications medical system 30 as schematically shown in FIG. The present invention also relates to novel parts thereof and methods of use useful in various medical applications, as described and demonstrated below.

【0035】

One feature of the system 30 of the present invention is a completely wireless new implantable telecommunications medical sensor 50 and a new signal reading and charging device 140 that operatively communicates with the sensor 50 in the patient's body or The purpose is to remotely detect or measure a characteristic or parameter (or a number of different parameters, including the amplitude of a parameter) within an organ or tissue within the patient's body.

【0036】

Remote communication type sensor As schematically shown in FIG. 1, the telecommunications medical sensor 50 comprises a housing 52 made of a biocompatible material such as polysilicon or titanium. The housing 52 preferably has a cylindrical shape, but any shape of housing 52 can be used. The housing 52 has a length of about 4 mm to 5 mm and a diameter of about 2.5 mm to 3 mm. Further, the housing 52 may be smaller, for example, having a length of 3 mm and an outer diameter of 1 mm to 2 mm. Housing 52 has a cylindrical wall with a thickness of approximately 250 μm. A flexible thin film 56 made of a deformable material is fixed to one end of the housing 52. The outer surface of the housing 52 is provided with a notch 58 and a peripheral groove 60 to facilitate delivery and implantation of the sensor 50.

【0037】

The thin film 56 is made of a flexible or deformable material such as polysilicon rubber or polyurethane. The thin film 56 has a thickness of about 20 μm and a diameter of about 1.5 mm to 2 mm. Normally, the thin film 56 is displaced outward from the housing 52 by the internal pressure of the housing 52. Each time the external pressure of the housing 52 exceeds the internal pressure of the housing 52, the thin film 56 is forcibly deformed toward the inside of the housing 52.

【0038】

The deformable and usually displaced outside of the housing 52 allows the thin film 56 to respond directly to the environment of the tissue or organ being monitored and / or measured for a particular property or parameter. Even the slightest change in these characteristics, that is, the parameters, causes the thin film 56 to deform toward the inside of the housing 52. Therefore, there is a direct relationship (correspondence relationship) between the measured characteristic, that is, the change in the parameter, and the deformation action, that is, the amount (degree) of movement of the thin film 56.

【0039】

It is important to note that the thin film 56 has a relatively large dimensional area compared to solid state thin film devices such as piezoelectric sensors or assembly memory chips that utilize thin films. Therefore, the electronic engineering requirements of the sensor 50 are small. In addition, the thin film 56 causes much greater deformation than solid-state thin films.

【0040】

Further, the sensor 50 has an antenna coil 68, and the antenna coil 68 is connected to an internal component of the sensor 50 by an antenna lead wire 70. The antenna coil 68 is an inductance coil having a spiral coil shape. The material used for the antenna wire is a coated metal of about 90% silver and about 10% platinum iridium. The antenna coil 68 is preferably formed by twisting 20 to 25 wires having a thickness of 30 μm. The outer diameter of the antenna is 1.5 cm to 2 cm (Fig. 2).

【0041】

Therefore, due to these characteristics, the antenna coil 68 has a very low parasitic capacitance. Further, the antenna coil 68 has a very high conductivity due to its silver / platinum component wire, and is extremely flexible.

【0042】

Although the antenna coil 68 has been described as being outside the housing 52, the extension of the invention may include any type of suitable antenna, such as an antenna housed inside the housing 52.

【0043】

The sensor 50 further has a plurality of fixing legs 64. The fixing leg 64 is elastically displaced toward the outside of the housing 52. The number of anchoring legs 64 may vary depending on the desired degree of anchoring and the shape of the anatomical structure in which the sensor 50 should be located. The fixing leg 64 is formed from a wire using a shape memory alloy such as a nickel-titanium alloy (NiTinol). The anchoring leg 64 has a concave shape with a curvature that bends and enters the inside of the tissue or organ to which the sensor 50 should be anchored. Other suitable shapes for the anchoring leg 64 are also considered here.

【0044】

If desired, the sensor 50 is coated with a non-thrombogenic agent such as Heparin or anticoagulant agent prior to implantation to prevent thrombi, blood clots and the like.

【0045】

FIG. 3 is a diagram showing an alternative embodiment of the sensor 50. The sensor 50 has a tapered end 54 on the housing 52. The tapered end 54 is located on the tissue penetration end 55 and the outer surface of the tapered end 54 to facilitate anchoring by screwing the tapered end 54 of the housing 52 directly into the tissue. It has a spiral streak 57.

【0046】

FIG. 4 is a diagram showing another alternative form of the sensor 50. The sensor 50 has a plurality of tissue penetrating claws 59 fixed to the tapered end 54 of the housing 52. These claws 59 have a tissue penetration end that bends outward and is separated from the tissue penetration end 55. Therefore, along with the tissue penetration end 55, the tissue penetration claw 59 firmly holds the tissue and firmly anchors the housing 52 to the tissue.

【0047】

As shown in FIG. 5, a microprocessor 90 in the form of a microchip is provided in the internal space of the housing 52, and the microprocessor 90 is fixed to one of the inner walls of the housing 52. The lead wire 70 of the antenna coil 68 is operatively connected to the microprocessor 90. The microprocessor 90 has an array 92 composed of a plurality of photoelectric cells 95. The photoelectric cells 95 are arranged in a patterned form, eg, in eight staggered rows with eight photoelectric cells 95 in each row. A reference photoelectric cell 97 is arranged at one end of an array 92 having a total of 64 photoelectric cells 95 as shown in FIG. The photoelectric cell array 92 has a resolution in the range of 64. The pitch distance of the photoelectric cell 95 is about 1/4 of the dimension of the photoelectric cell 95. Further, the reference photoelectric cell 97 has approximately a pitch dimension of the photoelectric cell 95, for example, a dimension of about 1/4 of the dimension of the photoelectric cell 95. Therefore, the reference photoelectric cell 97 has a resolution equal to a movement of 1/4 of the dimension of the photoelectric cell 95.

【0048】

A light emitting diode (LED) 100 is operatively connected to the microprocessor 90, and the LED 100 is arranged above the photoelectric cell array 92 in parallel with a distance from the array 92. A shutter 62 is connected to the inner surface of the thin film 56, and the shutter 62 extends from the thin film 56 to the inside of the housing 52 along the longitudinal direction. The shutter 62 has a substantially D-shaped shape and extends longitudinally between the LED 100 and the array 92. The shutter 62 is made of an aluminum alloy and is arranged such that the flat surface of the shutter 62 faces the array 92 directly. The shutter 62 is connected to the thin film 56 so as to interlock with the thin film 56. Thus, when the thin film 56 is displaced inward of the housing 52 due to monitored or measured tissue or organ parameters, the shutter 62 is directly related to the inward movement of the thin film 56 as it deforms. Extends longitudinally across the plurality of photoelectric cells 95 of the array 92. Similarly, when the thin film 56 deforms outward from the housing 52, the shutter 62 moves longitudinally outward from the end of the housing 52 along with the thin film 56. In this way, the shutter 62 covers (blocks) the plurality of photoelectric cells 95 according to the degree of movement of the thin film 56. Therefore, when the shutter 62 is located over a certain number of photoelectric cells 95, the light from the LED 100 is prevented from reaching these photoelectric cells 95 and affects the transmission of signals from these photoelectric cells 95. This arrangement constitutes a power efficient analog-to-digital (A / D) conversion. This is because the number of photoelectric cells 95 turned on or off can be easily counted according to the amount of shutter movement. Therefore, it is an analog / digital conversion. In this way, the microprocessor 90 is operatively connected to the thin film 56.

【0049】

Since the reference photoelectric cell 97 is located at the end of the array 92 farther from the thin film 56, it is not obscured by the shutter 62. Even if the shutter 62 and the thin film 56 are most displaced inside the housing 52, the shutter 62 and the thin film can be used as the reference signal for the sensor 50 by permanently exposing the reference photoelectric cell 97 to the LED 100. 56 is adjusted. Moreover, the power consumption of this photoelectric cell is very low.

【0050】

As best shown in FIG. 6, the microprocessor 90 is a circuit in which the antenna coil 68 and the resonant capacitor 102 operate as the resonant oscillator of the sensor 50. The antenna coil 68 receives the transmitted RF (radio frequency) signal transmitted from the signal reading and charging device 140 shown in FIGS. 9 and 10. The RF signal received by the antenna coil 68 is a charging signal that supplies power to the microprocessor 90. Upon receiving this RF charging signal, the antenna coil 68 and the resonant capacitor 102 resonate to charge the charging capacitor 114 via the diode 116. When a predetermined voltage threshold of about 1.2V is reached, the charging capacitor 114 feeds the LED 100 and the logic circuit 91 via the control unit 104. When the LED 100 is powered by the charging capacitor 114, the LED 100 emits light toward the photoelectric array 92, which is maintained at a negative voltage.

【0051】

As shown in FIG. 7, each photoelectric cell array 92 has a P.₁, P₂, ... P₆₄, P_refIndicated by. Each photoelectric cell 95 (P₁To P₆₄) Is C₁, C₂, ... C₆₄It is connected in parallel to a plurality of comparators 120 indicated by. The reference photoelectric cell 97 is each comparator 120 (C.₁To C₆₄), And supplies each comparator 120 with a reference signal to be compared with the signal received from each corresponding photoelectric cell 95. The logic circuit 91 is fed and controlled by the control unit 104 and the clock 106. The control unit 104 is connected to each comparator 120.

【0052】

These comparators 120 have multiple buffer cells 129 (Comparator C).₁To C₆₄A buffer 126 having a total of 64 buffer cells) corresponding to the above is operatively connected. Each buffer cell 129 is a flip-flop or storage cell and the corresponding comparator C.₁To C₆₄Receive the signal from. As a result, these signals are 64-digit long binary numbers (a sequence of 0s and 1s). During one clock cycle, all buffer cells 129 are filled, and each buffer cell 129 stores a number of 0 or 1 within it. After all 64 buffer cells 129 are filled with their respective binary values, a digital signal indicating all 64 bits is transmitted by the control unit 104 to the signal reading and charging device 140. After transmitting this digital signal, the control unit 104 is reset by the clock 106 and waits for further signals from the signal reading and charging device 140. The binary number is encrypted by the signal reading and charging device 140, which will be described in detail later.

【0053】

When the 64 buffer cells 129 are filled, a digital signal is transmitted from the buffer 126 to turn on the switch 112. As a result, a digital signal is transmitted from the antenna coil 68 to the antenna coil 162 of the signal reading / charging device 140.

【0054】

A major feature of the telecommunications medical system 30 of the present invention is that, despite the fact that the sensor 50 is a wireless responder and its passive nature, it is used in the sensor 50, such as the photoelectric cell array 92. It is a low-power device with high-speed update speed capability due to its unique analog-to-digital (A / D) conversion mechanism. The array 92 directly converts the deformation of the thin film 56 into a digital signal, eliminating the power consumption required by conventional A / D converters.

【0055】

Signal reading and charging device As shown in FIG. 9, the signal reading and charging device 140 according to the present invention is used by being arranged on the outside of the patient's body or on the outer surface of the patient's body. The signal reading and charging device 140 has a casing 145 that is a housing. Casing 145 has a liquid crystal display (LCD) display screen 172 attached to the opening of casing 145. The signal reading / charging device 140 is also generally referred to as a reading / charging device, a reader / charger or a reader / charger device, and is activated by a power switch (toggle) 146 extending from the casing 145. Ru. The antenna coil 162 operatively communicates with the antenna coil 68 of the sensor 50 by inductance coupling.

【0056】

As shown in FIG. 10, when the logic circuit 91 transmits a digital signal from the sensor 50 via the antenna coil 68 of the sensor, the coupling coefficient of the antenna coil 162 of the reader / charger changes, and the reader / charger The coupling coefficient is detected by a deep detector 168 operatively connected to the antenna coil 162 of the. The deep detector 168 has the sensitivity to detect a change in signal amplitude even when the change in amplitude is as low as about 0.01%.

【0057】

A read / charge control unit 154 is operatively connected to the deep detector 168 to determine a threshold for the deep detector 168. Further, the logic control unit 154 has a power supply unit 151 that supplies power to the components of the signal reading / charging device 140.

【0058】

The circuit 150 of the signal reading and charging device further includes a processing unit 170, which is operatively connected to the logic control unit 154. The processing unit 170 has an algorithm that converts the digital signal received from the sensor 50 (FIG. 9) into medical parameters, physical condition or characteristic measurement parameters detected by the embedded sensor 50. Further, the processing unit 170 uses an encryption algorithm such as the exclusive OR (XOR) method or the RSA method (RSA Security, Inc.) to encrypt a digital signal (64-bit signal). Has.

【0059】

For example, if the measured parameter is the hemodynamic blood pressure in an organ such as the space of the heart, when the processing unit 170 receives a digital signal, the processing unit 170 will use that algorithm to create a digital signal (binary). ) Is converted to a pressure value. This conversion uses a lookup comparison table or the following analytical formula (1) that expresses the relationship between the displacement of the shutter 62 of the sensor 50 and the external pressure applied to the thin film 56. P = (KD³/ A²) X² (1) Here, P is the pressure value, D is the thickness of the thin film, A is the radius of the thin film, X is the displacement from the equilibrium state, and K is a constant.

【0060】

The liquid crystal display screen 172 is operatively connected to the processing unit 170 to display the measured parameters (hemodynamic blood pressure in the above example) converted from the digital signal in real time.

【0061】

By using the signal reading and charging device 140 outside the patient's body, a series of both mean and effective values (individual values) of the sampled parameters for determining the characteristics of the parameters such as amplitude. Parameter reading can be obtained.

【0062】

When measuring the properties of body fluids such as blood, the signal reading and charging device 140 has an effective reading amount in the range of 5 cm to 25 cm around the sensor 50, preferably in the range of about 10 cm to 15 cm. Maintain effective reading. Further, the remote communication type medical system 30 via the sensor 50 and the signal reading / charging device 140 enables a plurality of samplings per second. Preferably, according to the present invention, it is possible to read about 10 to 20 times per second.

【0063】

Other features according to the invention when used for pressure monitoring inside the heart space are pressure monitoring in the range of ± 30 mmHg, accuracy of ± 1 mmHg (with an integral of 5 msec), repeatability of ± 1 mmHg (5 msec). (Integral of). Importantly, the pressure limit can be easily changed by changing the size and dimensions, such as the width of the thin film, which does not require changes in the electronics. This is important in that it is possible to allow the present invention to be adapted to a variety of applications while using the same design.

【0064】

The control unit 154 is operatively connected to a sine wave driver 158 that produces a sinusoidal signal of approximately 4 MHz to 6 MHz. The sine wave signal is generated by the sine wave driver 158 and supplied to the antenna coil 162 of the signal reading and charging device via the capacitor 160 to feed or charge the sensor 50 as described above. Sent to 68.

【0065】

Medical procedure As mentioned above, the telecommunications medical system 30 according to the invention is almost any medical diagnostic procedure in which it is desirable to implant the sensor 50 in a location within the body, particularly in a tissue or organ of interest. Useful in type. The telecommunications medical system 30 according to the invention is capable of rapidly sampling various parameters or variables of any physical condition in a patient's body where interest is of interest, thus providing remote tissue or organ status. Expected to monitor and diagnose. Due to the wireless nature of the telecommunications medical system 30, these types of procedures are performed in a completely non-invasive manner with minimal injury to the patient.

【0066】

Specific examples of the telecommunications medical system 30 according to the invention, its components and how to use them are in the field of heart failure (CHF). CHF is defined as the condition in which the heart 400 (Fig. 11) is unable to pump enough blood to other organs in the body. This is caused by narrowing of the arteries that supply blood to the myocardium with coronary artery disease, past heart attacks, or myocardial infarction. Myocardial infarction is a disease of the heart valve (semilunar valve, tricuspid valve 417 or mitral valve 418) associated with scar tissue, hypertension, past rheumatic fever, or other that interferes with the normal functioning of the myocardium. Due to the cause. Other causes include a natural disorder of the myocardium itself called hypertrophic cardiomyopathy, a natural heart disorder such as a congenital heart disease, an infection of the valvular heart and / or the myocardium itself (endocarditis, myocarditis). There is a flame).

【0067】

The diseased heart 400 maintains its function, but not as efficiently as it should. People with CHF are short of breath and easily tired, so they can't do their best. When the blood that flows out of the heart 400 slows down, the blood that returns to the heart 400 through the veins stagnates, causing congestion in the tissues. This often results in swelling (edema). Such edema most commonly occurs in the legs and ankles, but can also occur in other parts of the body. Frequently, fluid collects inside the lungs, which interferes with breathing, especially when a person is lying down. Defects in the heart also adversely affect the kidney's ability to process salt and water. Accumulated water increases edema.

【0068】

CHF is the most common heart disease in the United States, and it is estimated that more than 5 million patients suffer from it. One of the more useful hemodynamic parameters measured and diagnosed in patients with CHF is the blood pressure of the left atrium 410, or left atrium (LA) pressure. To date, this parameter has been measured by inserting a catheter into the invasive right heart using a specialized balloon catheter, such as the Swan-Gantz catheter.

【0069】

Therefore, in mitigating the effects of CHF, a specific space of the heart 400 (either right atrium 415, right ventricle 419, left atrium 410 or left ventricle 420) using the telecommunications medical system 30 according to the present invention. It is desirable to measure the blood pressure inside the heart.

【0070】

Therefore, in performing the preferred method according to the invention, the blood pressure in the left atrium 410 of the heart 400 can be directly monitored. Therefore, it is desirable to implant the sensor 50 in the foramen ovale 407 in the septum 405.

【0071】

Regarding the detailed structure of the septum 405, in about 15% of the standard population, the foramen ovale 407 has pre-existing holes or openings. This hole remains open or is usually covered with a small tissue valve. In 85% of the standard population, the foramen ovale 407 is completely closed and the septum 405 is unperforated.

【0072】

(1) Method using a catheter According to the method according to the present invention, it has been found that the method using a catheter is particularly useful for a group of patients who already have a pre-existing hole in the foramen ovale 407. Therefore, in performing this method according to the present invention, first, a transesophageal ultrasonic probe (not shown) is inserted into the patient's mouth and placed in the esophagus. In most cases, the transesophageal ultrasound probe is located approximately 30 cm to 35 cm from the mouth, just above the patient's stomach.

【0073】

A wire (not shown) is inserted into the right atrium 415 through a suitable blood vessel, such as the inferior vena cava 408, guided by transesophageal ultrasound. In the right atrium 415, the wire is passed through the foramen ovale 407 by gently lifting a piece of tissue through the opening of the foramen ovale 407. Once the wire is inserted into the foramen ovale 407, guide the wire to one of the pulmonary veins 416 for proper placement and anchoring in the opening of the pulmonary vein 416, i.e. for the placement of the tip of the wire. To do. Therefore, the pulmonary vein 416 is a very reliable and stable anchorage for the wire.

【0074】

Once the wire is properly placed in the fossa ovalis 407 and anchored in the pulmonary vein 416, the sheath of the catheter (over-the-wire type, not shown) is fitted by the wire to the right atrium 415 and Guide to fossa ovalis 407 and place it very close to the opening of the left atrium 410, eg, the pulmonary vein 416.

【0075】

Once the catheter sheath is properly placed, the wire is removed from the patient's heart 400 and the sensor 50 is delivered by the catheter sheath using one of many standard catheter delivery devices (not shown). Therefore, the sensor 50 can be delivered with one of the usual catheter-based delivery devices commonly used for delivery of implantable pacemakers, electrodes, atrial septal defect (ASD) occlusion devices, and the like. Therefore, the telecommunications medical sensor 50 can be delivered by a typical delivery device such as the Amplatzer® delivery system manufactured by AGA Medical Corporation located in Golden Valley, Minnesota.

【0076】

After placing the catheter sheath, the sensor 50 is deployed from the catheter sheath to the foramen ovale 407, as best shown in FIG. Once this deployment is complete, the sensor 50 uses the anchoring leg 64 to anchor the sensor 50 to the septum 405 and close the opening of the foramen ovale 407.

【0077】

(2) How to move forward For patients who do not have a pre-existing opening in the foramen ovale 407, the sensor 50 is placed in the foramen ovale 407 by means of an anterograde approach. Again, a transesophageal ultrasonic probe is placed in the patient's esophagus as described above. Under the guidance of transesophageal ultrasound imaging, an opening is formed in the septum 405 of the foramen ovale 407 to accommodate the sensor 50. For example, this opening is located in St. Paul, Minnesota. It is formed with a standard needle catheter (not shown) such as the BRK series Transseptal Needle manufactured by Jude Medical, Inc. Therefore, under the guidance of transesophageal ultrasound, the needle catheter is first placed in the right atrium 415 and then in the foramen ovale 407. At this location, the tip of the needle of the needle catheter penetrates the foramen ovale 407 and is inserted into the left atrium 410 through the opening newly formed in the foramen ovale 407 by the needle catheter. Once the opening of the foramen ovale 407 has been formed, the sensor 50 is inserted and placed in the opening of the foramen ovale as shown in FIG. 12 by a delivery device such as the delivery device described above. After the anchoring leg 64 has been deployed, the opening of the foramen ovale 407 is closed by the sensor housing 52 and sensor 50 firmly secured to the septum 405.

【0078】

Importantly, according to the steps of each method of the invention, transesophageal ultrasound imaging is utilized in both the catheter-based and advancing methods as described above. Since any of the methods according to the present invention is used with transesophageal ultrasound guidance, other visualization methods such as X-ray perspective can be excluded. The method itself according to the present invention can be performed as a clinical procedure in an outpatient clinic or a doctor's office. By eliminating the need for X-ray fluoroscopy, the methods according to the invention also eliminate the need to perform the procedure in a catheter laboratory, which only increases the time and cost of the procedure and gives the patient time and inconvenience. To do.

【0079】

After implanting the sensor 50 in the patient's septum 405, the patient is given standard procedures to prevent extra blood clots and endothelium formation. For example, it is common practice to prescribe at least one of an anticoagulant such as heparin and aspirin over a period of time, such as 6 months.

【0080】

To monitor the pressure of the left atrium 410 in real time, the sensor 50 is secured to the septum 405 by any of the methods described above. Since the sensor 50 is a radio responder and a low power receiver with a battery, the sensor 50 does not interfere with the natural functioning of the heart 400 and is truly minimally invasive.

【0081】

By using the signal reading and charging device 140 outside the patient's body, a continuous pressure reading of both the mean pressure and the vibration value of the left atrium 410 provided by the sensor 50 can be obtained.

【0082】

According to the telecommunications medical system 30, the signal reading and charging device 140 has an effective reading around the sensor 50 in the range of 5 cm to 25 cm, preferably in the range of about 10 cm to 15 cm. maintain. In addition, the sensor 50 and the signal reading and charging device 140 allow multiple samplings per second. Preferably, according to the present invention, it is possible to read about 10 to 20 times per second.

【0083】

Other features according to the invention when used for pressure monitoring inside the heart space are pressure monitoring in the range of ± 30 mmHg, accuracy of ± 1 mmHg (with an integral of 5 msec), repeatability of ± 1 mmHg (5 msec). (Integral of).

【0084】

Another embodiment of the sensor 50 according to the invention includes a ring member 65 movably attached to the housing 52, as best shown in FIGS. 13 and 14. The ring member 65 is located at the proximal and distal ends of the housing 52. Each ring member 65 forms a complete loop and has a tissue engaging surface 66 for contacting and engaging the tissue 402 (FIGS. 19-25).

【0085】

The ring members 65 are arranged in pairs around the longitudinal axis L of the housing 52 at both the proximal and distal ends of the housing 52. Each ring member 65 is shown as a pair of fixing members at the proximal and distal ends of the housing 52, and the desired number of ring members 65 in the present invention is conceivable.

【0086】

The ring member 65 is made of a molded metal material such as nickel titanium alloy (NiTi). In addition, other suitable molded storage materials such as molded storage plastics or flexible polymers are also considered by the present invention. The ring member 65 functions as a fixing member for fixing the sensor housing 52 between the tissues 402.

【0087】

As shown in FIGS. 13 and 14, the ring member 65 is movably attached to the housing 52 and around both the distal and proximal ends of the housing 52, centered on the longitudinal axis L of the housing 52. Is located in. The ring member 65 is movable in the R direction from the closed position (FIG. 14) to the deployed position (FIG. 13). The range of movement of the ring member 65 between the closed position and the unfolded position can be moved to the closed position so that the ring member 65 is substantially parallel to the longitudinal axis L of the housing 52 as shown in FIG. , A desired range of movement is included as long as it is movable in a deployment position such that it is approximately perpendicular to the axis L of the housing 52 as shown in FIG.

【0088】

Preferably, when the ring member 65 is in the closed position, the orientation of the ring member 65 is in the range of approximately 0 ° to 30 ° with respect to the longitudinal axis L of the housing 52. Also, preferably, when the ring member 65 moves to the unfolded position, the unfolded position is in the range of approximately 40 ° to 90 ° with respect to the longitudinal axis of the housing 52.

【0089】

15 and 16 show another embodiment of the implantable medical device 50, which is elastically biased to the housing 52 through a direct connection to an elastic member 67 such as a eccentric spring. Has a ring member 65. The movement and deployment of the ring member 65 between the closed position and the deployed position is the same embodiment as the method described above as the embodiment of FIGS. 13 and 14. Each spring 67 is connected to the ring member 65 and the housing 52 at the proximal and distal ends of the housing 52.

【0090】

FIG. 17 is a diagram showing another embodiment of the implantable device (sensor) 50 having the ring member 69. The ring member 69 forms an incomplete loop and is connected to the spring 67 at the proximal and distal ends of the housing 52 to elastically move the ring member 69. The ring member 69 includes a tissue engaging surface 69a to contact and engage the tissue during deployment of the device 50. As described above, the ring member 69 can move in the R direction toward the longitudinal axis L when moving to the closed position, and moves away from the longitudinal axis L of the housing 52 when moving to the deployed position. ..

【0091】

FIG. 18 shows another embodiment of the medical device 50 according to the invention having a ring member 71 having a concave contour in the form of an incomplete loop. The ring member 71 has a tissue engaging surface 73, which is concave to contact and engage the tissue when the ring member 71 moves to the unfolded position as shown in FIG. It is a face. Each ring member 71 is elastically biased to the housing 52 by connecting to the housing 52 through a spring 67. Similar to the above-described movement for the above-described embodiment, the ring member 71 is movable between the closed position and the expanded position with respect to the longitudinal axis L of the housing 52.

【0092】

According to the present invention, the ring members 65, 69 and 71 are preferably made of a shape memory material such as nitinol. Also, in some embodiments, the housing 52 is preferably made of shape memory material as well. Further, in the case of the embodiment using the spring 67, the ring members 65, 69 and 71 can also be made of shape memory material such as other metal alloys, plastics or polymers.

【0093】

The method according to the invention allows implantable medical devices 50 to be deployed within or between various tissues 402, eg, septum 405 (FIGS. 11 and 12). When deploying the medical device (sensor 50) according to the present invention, the sensor 50 is housed and housed within the body of a catheter 77 having a distal end 79, as best shown in FIGS. 19-25. When the sensor 50 is housed in the catheter 77, the ring member 65 is housed in a collapsed closed shape approximately parallel to the longitudinal axis of the housing 52.

【0094】

The first step of the method according to the invention requires that the distal end 79 of the catheter 77 be placed within the tissue 402. Catheter 77 is placed within tissue 402 so that it is placed between the two sides of tissue 402. At this point, the distal end 79 of the catheter is placed on the first side of tissue 402 as shown in FIG. The deployment mechanism 81 associated with the catheter 77 is used to move the sensor 50 from the distal end 79 of the catheter 77 as shown in FIG. The sensor 50 is at least partially at the distal end of the catheter 77 so that the ring member 65 at the distal end of the housing 52 is moved to a deployment position, eg, a deployment position approximately perpendicular to the longitudinal axis L of the housing 52. Moved from 79. The deployment mechanism 81 has various forms such as a push rod capable of advancing or moving the sensor 50 from the distal end 79 of the catheter 77, a movably actuated distal jaw or other member.

【0095】

As best shown in FIGS. 21 and 22, the housing 52 is operated so that the distal end 79 of the catheter is manipulated so that the tissue engaging surface 66 of each ring member 65 contacts and engages with the first side of the tissue 402. A ring member 65 at the distal end of the is arranged. At this point, the tissue engaging surface 66 of the ring member 65 secures the distal end of the housing 52 to the first side of the tissue 402.

【0096】

The next step in the method according to the invention is that the housing 52 is advanced by the deployment mechanism 81 over the distal end 79 of the catheter 77 and the ring member 65 is approximately perpendicular to the deployment position, eg, the longitudinal axis L of the housing 52. Includes advancing and moving the sensor 50 from the distal end 79 of the catheter 77 to move to a position. At this point, the tissue engaging surface 66 of the ring member 65 at the proximal end of the housing 52 contacts and engages with the opposite side (second side) of the tissue 402.

【0097】

When the sensor 50 is completely moved from the distal end 79 of the catheter, the catheter 77 is pulled from the tissue 402 as shown in FIG. As shown in FIGS. 23, 24 and 25, the tissue engaging surface 66 of the ring member 65 at the proximal end of the housing 52 contacts, engages, is secured and has a tissue on the second side of the tissue 402. Complete positioning and fixing of sensor 50 and housing 52 between 402. Therefore, the devices and methods of the present invention are used in situations where medical devices need to be implanted on or between two sides or layers of tissue 402. To perform diagnostic and / or therapeutic procedures, as described above, for medical procedures that monitor the parameters of the ventricles of the heart in relation to the heart. The product of the present invention is deployed between partition walls 405 (FIGS. 11 and 12).

【0098】

Having described preferred embodiments of medical systems, devices, components and methods of use thereof, it will be appreciated that the principles of the present invention can also be used for other types of objects. Preferred embodiments have been described for illustration purposes only, and the extension of the present invention is limited only by the claims.

【0099】

Specific embodiments of the present invention are as follows. (1) The method according to claim 1, wherein the first set of fixing members is elastically moved from the closed position to the deployed position. (2) The method according to embodiment (1), wherein the second set of fixing members is elastically moved from the closed position to the deployed position. (3) It has a step of maintaining the first set of fixing members and the second set of fixing members in a closed position within a range of approximately 0 ° to 30 ° with respect to the longitudinal axis of the catheter. The method according to embodiment (2). (4) It has a step of deploying the first set of fixing members and the second set of fixing members in a deployment position in a range of approximately 40 ° to 90 ° with respect to the longitudinal axis of the catheter. The method according to embodiment (3). (5) The method according to embodiment (4), which comprises the step of moving the medical device from the distal end of the catheter by a deploying mechanism.

【0100】

(6) The method according to embodiment (4), which comprises the step of deploying the medical device in heart tissue. (7) The method according to embodiment (6), which comprises a step of deploying the medical device in a partition wall.

【0101】

[Effect of the invention]

According to the method of the present invention, the transplanted member can be fixed in the tissue by a simple procedure.

[Simple explanation of drawings]

[Figure 1]

It is a schematic diagram which shows the remote communication type medical sensor which concerns on this invention.

[Figure 2]

It is a top view of the sensor of FIG.

[Fig. 3]

FIG. 5 is a schematic diagram illustrating an alternative embodiment of the sensor of FIG. 1 having a spiral streak and a tapered tip with a tissue penetration end for anchoring to the tissue.

[Fig. 4]

FIG. 5 is a schematic diagram illustrating another alternative embodiment of the sensor of FIG. 1 having a tissue penetration end and a tapered tip with a plurality of tissue penetration claws.

[Fig. 5]

It is a partial perspective view of the sensor of FIG. 1 with some parts removed in order to expose the parts inside the sensor.

[Fig. 6]

It is the schematic which shows the microprocessor circuit for the sensor which concerns on this invention.

[Fig. 7]

It is the schematic which shows the logic circuit of the microprocessor circuit of FIG.

[Fig. 8]

It is the schematic which shows the array of photoelectric cells for the sensor which concerns on this invention.

[Fig. 9]

It is a schematic diagram which shows the remote communication system which concerns on this invention which has the sensor of FIG. 1 and a signal reading and charging device which is arranged away from this sensor and communicates with a sensor.

[Fig. 10]

It is the schematic which shows the reading / charging circuit of the signal reading and charging apparatus of FIG.

[Fig. 11]

It is a schematic diagram of a patient's heart.

[Fig. 12]

FIG. 6 is a schematic showing a sensor fully deployed within an opening of a tissue according to the present invention.

[Fig. 13]

FIG. 5 is a drawing of a implantable medical sensor having a first set of fixing members and a ring member with a second set of fixing members at a position unfolded with respect to the longitudinal axis of the housing of the device.

[Fig. 14]

It is a figure which shows the device of FIG. 13 which has the ring member which provided with the 1st set of fixing members and the 2nd set of fixing members at the position closed with respect to the longitudinal axis of the housing of this device.

[Fig. 15]

Other medical devices having a first set of fixing members attached to a deviating spring and a ring member as a second set of fixing members in a position unfolded with respect to the longitudinal axis of the housing of the device according to the invention. It is a schematic diagram of an embodiment.

[Fig. 16]

FIG. 5 is a perspective view of the device of FIG. 15 having a first set of fixing members and a second set of ring members of the fixing members at a closed position with respect to the longitudinal axis of the housing of the device according to the present invention.

[Fig. 17]

FIG. 6 illustrates another embodiment of a implantable medical device according to the invention comprising a ring member as an incomplete loop elastically biased into a housing by a spring.

[Fig. 18]

FIG. 6 is a schematic diagram showing another embodiment of a implantable medical device according to the invention provided with a ring member formed in an incomplete loop and having a concave contour according to the invention.

[Fig. 19]

FIG. 6 is a schematic diagram showing a method according to the invention in which a catheter having a implantable medical device according to the invention is placed in a tissue.

[Fig. 20]

FIG. 5 illustrates a method according to the invention in which a portion of a medical device is moved from the distal end of a catheter to move a first set of fixation members to a deployment position.

[Fig. 21]

FIG. 5 is a schematic diagram showing a method according to the invention in which the first set of fixing members is pulled to one side of the tissue.

[Fig. 22]

It is the schematic which shows the method by this invention that the engaging surface of the 1st set of fixing members is engaged with the structure of one side.

[Fig. 23]

FIG. 5 illustrates a method according to the invention in which the medical device is moved from the distal end of the catheter such that the second set of fixation members is moved to the unfolded position.

[Fig. 24]

The method according to the invention, in which the catheter is removed from the tissue after the medical device is fully deployed from the distal end of the catheter and the tissue engaging surface of the second set of fixation members engages the tissue opposite the tissue. It is a figure which shows.

[Fig. 25]

FIG. 5 illustrates a method according to the invention in which a medical device is fully deployed and implanted between tissues.

[Explanation of symbols]

30 Remote communication type medical system 50 Remote communication type medical sensor 52 housing 54 Tapered end 55 Tissue penetration 56 thin film 57 Spiral streaks 58 notch 59 Tissue penetration claws 60 circumference groove 62 Shutter 64 Fixing legs 65 Ring member 66 Tissue engaging surface 68 Antenna coil 70 Antenna lead wire 77 Catheter 79 Distal end 90 microprocessor 91 Logic circuit 92 array 95 photoelectric cell Photoelectric cell for 97 standards 100 LED 102 Resonant capacitor 104 Control unit 106 clock 112 switch 114 Charging Capacitor 116 diode 120 comparator 126 buffer 129 buffer cell 140 Signal reading and charging device 145 Casing 146 power switch 150 circuits 151 Power supply 154 Reading / charging control unit 158 sine wave driver 160 capacitors 162 Antenna coil 168 Deep detector 170 processing unit 172 LCD display screen 400 heart 402 Organization 405 bulkhead 407 Foramen ovale 408 Inferior vena cava 410 Left atrium 410 Left atrium 415 Right atrium 416 Pulmonary vein 417 Tricuspid valve 418 Mitral valve 419 right ventricle 420 Left ventricle