JP2016174738A - Active clip for medical use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active clip for medical use capable of reducing a back flow from inferior vena cava to pulmonary artery through an artificial blood vessel according to a respiratory signal with a simple configuration.SOLUTION: An active clip 10 for medical use capable of reducing a back flow of blood in an artificial blood vessel includes a contraction part 12 as contraction means disposed so as to surround the outer periphery of the artificial blood vessel 41, for reducing a cross-sectional area of the artificial blood vessel 41. The contraction part 12 repeats the contraction by drive means for driving according to a respiratory signal. The contraction part 12 includes a cylindrical part 11 to surround the outer periphery of the artificial blood vessel 41, and an operating element for contracting the cylindrical part 11 in a radial direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a medical active clip.

In the treatment of heart disease, a method of surgically connecting between blood vessels using an artificial blood vessel and reconstructing a blood flow path is performed.
For example, in the treatment of congenital heart disease, the blood flow channel on the right ventricle side that cannot function sufficiently is connected by suturing the inferior vena cava and the pulmonary artery blood vessel with an artificial blood vessel, and blood perfusion from the whole body Surgery is used to bypass the lung directly to the pulmonary circulation without going through the heart.
The method of creating a blood flow path from the vena cava to the pulmonary circulation without passing through the heart can secure physiological blood flow to the systemic circulation and maintain long-term blood flow. It is widely used as one of the final forms of revascularization.

International Publication No. 98/08466 JP-T-2004-509699

Manoj Kuduvalli, Kenneth E. McLaughlin, Dipesh B.Trivedi, and Marco Pozzi, “Norwood-Type Operation With Adjustable Systemic-Pulmonary Shunt Using Hemostatic Clip”, The Annals of thoracic surgery, 2001 Aug, Vol. 72, No. 2, pp.634-5 Osamu Namura, “Experimental Study on Stepwise Increasing Method of Short-Circuit Flow in Modified Blalock-Taussing Surgery”, Niigata Medical Society Journal, 1997, Vol. 111, No. 8, p. 496-508

  However, if the inferior vena cava and the pulmonary artery are connected via an artificial blood vessel without going through the right ventricle of the heart, the right ventricular inflow / outflow valve that originally exists anatomically does not exist in the flow path. The blood flows back to the inferior vena cava via an artificial blood vessel. In this case, it has been suggested that in the long term, there is a possibility that the inferior vena cava pressure increases due to the regurgitation and the veins of organs such as the liver joining the inferior vena cava may be damaged. Specifically, the blood flow flowing into the lungs from the inferior vena cava via an artificial blood vessel connected by surgery and the blood flow flowing back from the lungs are affected by respiration. Specifically, as the intrathoracic pressure increases, the backflow of blood from the pulmonary artery to the inferior vena cava via the artificial blood vessel increases.

  Non-Patent Document 1 is a document related to Norwood surgery for left ventricular hypoplastic syndrome, which is a type of congenital heart disease, and describes a method for adjusting the size of a shunt that connects the systemic circulation and the pulmonary circulation. The method described in Non-Patent Document 1 is a method of adjusting the size by partially fastening a polytetrafluoroethylene tube with a clip, and this method is used for a patient with excessive pulmonary circulation. That is, Non-Patent Document 1 describes a clip that adjusts blood flow by tightening an artificial blood vessel from the outside.

  Non-Patent Document 2 is a document on an experiment related to a modified black-tausing operation for cardiac malformation. Non-Patent Document 2 describes a clip for restricting blood flow by sandwiching an artificial blood vessel.

  However, when the clip described in Non-Patent Document 1 or Non-Patent Document 2 described above is simply attached to an artificial blood vessel provided between the pulmonary artery and the inferior vena cava, the blood is not affected regardless of changes in intrathoracic pressure due to respiration. There is a problem that the flow rate is limited.

Patent Document 1 describes a device that regulates blood flow. This device includes an artificial blood vessel and a balloon inside a sheath, and it is described that the artificial blood vessel is narrowed by inflation of the balloon.
Patent Document 2 describes a device that reduces blood flow by tightening a body tube such as a blood vessel.
However, even if the stenosis of an artificial blood vessel due to balloon inflation according to Patent Document 1 or the method described in Patent Document 2 is simply applied to an artificial blood vessel provided between the pulmonary artery and the inferior vena cava, the intrathoracic pressure due to respiration Regardless of the change in the blood flow, there is a problem that the blood flow is limited.

  This invention makes it an example of a subject to cope with such a problem. That is, it is possible to provide a medical active clip that can reduce the backflow of blood in an artificial blood vessel according to a respiratory signal with a simple configuration, and to provide a medical active clip used for a cylindrical artificial organ or the like. The purpose is.

In order to achieve such an object, the medical active clip of the present invention has at least the following configuration.
A medical active clip for reducing blood backflow in an artificial blood vessel joining the inferior vena cava and the pulmonary artery,
The medical active clip is disposed so as to surround the outer periphery of the artificial blood vessel, and includes contraction means for reducing a cross-sectional area in the artificial blood vessel, and the contraction means repeats contraction by a driving means that is driven according to a respiratory signal. It is characterized by that.

ADVANTAGE OF THE INVENTION According to this invention, the medical active clip which reduces the backflow of the blood in an artificial blood vessel with a simple structure according to a respiration signal can be provided.
Moreover, the medical active clip used for a cylindrical artificial organ etc. can be provided.

The conceptual diagram which shows an example of the state which mounted | wore the artificial blood vessel with the medical active clip which concerns on embodiment of this invention. The conceptual diagram which shows an example of operation | movement of a medical active clip, (a) is a figure which shows an example of the active clip of an inhalation period, (b) is a figure which shows an example of the active clip of an expiration period. The block diagram which shows an example of the medical active clip which concerns on embodiment of this invention, and a respiration detection apparatus. The figure which shows an example of the expansion | deployment state of the cylindrical part of the medical active clip which concerns on embodiment of this invention, (a) is the front view, (b) is the left view, (c) is the right view, (D) is the top view, (e) is the bottom view, (f) is the back view. The figure which shows an example of the cylinder state and open state of the cylindrical part of a medical active clip, (a) is the front view, (b) is the left view, (c) is the right view, (d) is the right view. The top view, (e) is the bottom view, (f) is the back view, (g) is a perspective view, (h) is an end view of the cross section along the line AA ′ in (a). The figure which shows an example of the deformation | transformation state (closed state) of the cylindrical part of a medical active clip, (a) is a figure which shows an example of the shape of the upper side edge part, (b) is an example of the shape of a lower side edge part (C) is a perspective view from above, (d) is a perspective view from below. The figure which shows an example of operation | movement of a medical active clip, (a) is a perspective view which shows an example of an open state, (b) is a perspective view which shows an example of a deformation | transformation state (semi-closed state), (c) is a deformation | transformation state ( The perspective view which shows an example of a (closed state). The conceptual diagram which shows an example of the medical active clip which provided the cover member. The conceptual diagram which shows an example of a medical active clip of a normal / reverse phase series type. The figure which shows an example of a medical active clip, (a) is a figure which shows an example of an open state, The figure which shows an example of the closed state of (b). The figure which shows an example of a medical active clip. The conceptual diagram which shows an example of the characteristic measuring apparatus of a medical active clip. The figure which shows an example of the pressure in the artificial blood vessel in each form of a medical active clip. The conceptual diagram which shows an example of the acute animal experiment using a medical active clip. The figure which shows an example of the experimental result with respect to a medical active clip, (a) is a figure which shows an example of the pressure of the downstream of the artificial blood vessel in the obstruction | occlusion state of a medical active clip, (b) is an open state of a medical active clip The figure which shows an example of the pressure of the downstream of the artificial blood vessel of FIG. 1, (c) is a figure which shows an example of the flow volume (volume flow rate) in the artificial blood vessel in the obstruction | occlusion state of a medical active clip, (d) is a medical active clip. The figure which shows an example of the flow volume (volume flow volume) in the artificial blood vessel in the open state. The conceptual diagram explaining an example of the respiration detection by a respiration detection apparatus, (a) is a figure which shows an example of the respiration detection apparatus arrange | positioned in the chest, (b) is the acceleration detected by the respiration detection apparatus shown to (a). The figure which shows an example of the respiration signal according to a time change, (c) is a figure which shows an example of the respiration detection apparatus arrange | positioned in the abdomen, (d) is the time of the acceleration detected by the respiration detection apparatus shown to (c). The figure which shows an example of the respiration signal according to a change.

  The medical active clip according to the embodiment of the present invention is mounted so as to surround the outer periphery of the artificial blood vessel in blood flow reconstruction using the artificial blood vessel by surgery, and suppresses the backflow of blood to the vein side. Specifically, the medical active clip reduces blood regurgitation in an artificial blood vessel joining the inferior vena cava and the pulmonary artery in response to a respiratory signal. The active clip for medical use is disposed so as to surround the outer periphery of the artificial blood vessel, and includes contraction means for reducing the cross-sectional area in the artificial blood vessel, and the contraction means is repeatedly contracted by a driving means that is driven according to a respiratory signal. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The embodiment of the present invention includes the contents shown in the drawings, but is not limited to this. In the following description of each drawing, parts that are common to the parts that have already been described are assigned the same reference numerals, and duplicate descriptions are partially omitted.

FIG. 1 is a conceptual diagram showing an example of a state in which a medical active clip 10 according to an embodiment of the present invention is attached to an artificial blood vessel 41.
In heart disease treatment, a method of surgically connecting blood vessels using artificial blood vessels and reconstructing a blood flow path is performed. For example, in the treatment of congenital heart disease, the inferior vena cava 31 and the blood vessel of the pulmonary artery 32 located in the vicinity of the aorta 33 are sutured with an artificial blood vessel 41 in the blood flow channel on the right ventricle side that cannot perform a sufficient function. Thus, a surgical method is adopted in which blood perfusion from the whole body is bypassed directly to the pulmonary circulation without passing through the heart 30.
The method of creating a blood flow path from the vena cava to the pulmonary circulation without passing through the heart can secure physiological blood flow to the systemic circulation and maintain long-term blood flow. It is widely used as one of the final forms of revascularization.
In this embodiment, the medical active clip 10 is mounted so as to surround the outer periphery of the artificial blood vessel 41 that joins the inferior vena cava 31 and the pulmonary artery 32. The medical active clip 10 may be formed in a cylindrical shape, or may be formed in a predetermined shape such as a substantially C shape. The respiration detection device 20 is disposed, for example, in the vicinity of a lung or abdomen, and generates a respiration signal s corresponding to respiration.
The medical active clip 10 receives the respiration signal s from the respiration detection device 20 via a wireless or wired communication path, and drives the contraction unit by the driving unit according to the respiration signal s, and the contraction unit By reducing the cross-sectional area in the artificial blood vessel 41 and increasing the duct resistance (flow path resistance), the backflow from the pulmonary artery 32 to the inferior vena cava 31 via the artificial blood vessel 41 is reduced.

  FIG. 2 is a conceptual diagram showing an example of the operation of the medical active clip 10. Specifically, FIG. 2A is a diagram illustrating an example of the active clip 10 in the inspiration period, and FIG. 2B is a diagram illustrating an example of the active clip 10 in the expiration period.

The artificial blood vessel 41 is formed in a cylindrical shape from a flexible material, for example, a predetermined material such as a fluororesin such as PTFE (polytetrafluoroethylene) or ePTFE (expanded porous PTFE), or polyester. The artificial blood vessel 41 holds a fluid such as blood 4 so as to flow freely.
The pulmonary artery (PA) is located on one side of the artificial blood vessel 41, and the liver vein (HE) and the inferior vena cava are located on the other side. The cylindrical portion 11 of the active clip 10 is disposed so as to surround the outer periphery of the artificial blood vessel 41.
Examples of the material of the cylindrical part 11 include a flexible material such as PTFE (polytetrafluoroethylene) and ePTFE (expanded porous PTFE), a flexible material such as polyester, and a predetermined material such as metal. Can do.

  As shown in FIG. 2A, the contraction part 12 provided in the cylindrical part 11 of the medical active clip 10 during the inspiratory period is not contracted, and the cross-sectional area k in the artificial blood vessel 41 is It is a specified value and a small channel resistance.

  As shown in FIG. 2 (b), during the expiration period, the contracted portion 12 of the cylindrical portion 11 of the medical active clip 10 is contracted, and the cross-sectional area k in the artificial blood vessel 41 becomes smaller than the specified value. , Resulting in a large flow resistance. In this way, in the exhalation period, even if the intrapulmonary pressure is negative compared to the atmospheric pressure, the backflow from the pulmonary artery (PA) side to the liver vein (HE) or the inferior vena cava side is prevented. Can be reduced.

  When the expiration period is changed to the inspiration period, the contraction portion 12 provided in the cylindrical portion 11 of the medical active clip 10 is not contracted, and the cross-sectional area k in the artificial blood vessel 41 becomes a specified value. , The flow resistance becomes small. As described above, in the expiration period, the active medical clip 10 is configured not to obstruct the flow of blood in the artificial blood vessel 41.

  FIG. 3 is a block diagram showing an example of the medical active clip 10 and the respiratory detection device 20 according to the embodiment of the present invention.

  In the present embodiment, the respiration detection device 20 is arranged on the body surface such as the chest and abdomen, detects body movement according to respiration, and generates a respiration signal based on the detection result. The respiration detection device 20 includes an acceleration detection unit 21 such as an acceleration sensor, a communication unit 22, a CPU 23 as a control circuit, and the like. The CPU 23 is electrically connected to the acceleration detection unit 21 and the communication unit 22.

  The acceleration detection unit 21 is arranged in the lung, the abdomen, or the like or in the vicinity thereof, detects the acceleration of body movement, and outputs a signal indicating the acceleration to the CPU 23. The CPU 23 generates a respiration signal based on the signal indicating the acceleration from the acceleration detection unit 21, and the respiration signal is transmitted to the active clip 10 via the wireless or wired communication path by the communication unit 22 as a transmission unit. Output.

  In the above embodiment, the respiration detection device 20 detects body movements in the lungs and abdomen due to respiration or in the vicinity thereof using an acceleration sensor, and generates a respiration signal in response to the detection. is not. The respiration detection device 20 may be in any form as long as it can generate a respiration signal corresponding to respiration.

  The medical active clip 10 includes a control unit 101, a communication unit 102, a drive circuit 103 as a drive unit, a contraction unit 12 as a contraction unit, and the like. The control unit 101, the communication unit 102, and the drive circuit 103 are electrically connected by a communication line 105 or the like.

The communication unit 102 receives a respiration signal from the respiration detection device 20 and outputs it to the control unit 101.
The control unit 101 drives the drive circuit 103 based on the respiratory signal received by the communication unit 102 and controls the contracting unit 12 to repeat contraction according to the respiratory signal.

The drive circuit 103 contracts the contraction unit 12 under the control of the control unit 101.
The contraction unit 12 reduces the cross-sectional area in the artificial blood vessel in accordance with driving by the driving circuit 103. Specifically, the contraction unit 12 includes a cylindrical part that surrounds the outer periphery of the artificial blood vessel, an actuator (actuator) that contracts the cylindrical part in the radial direction, and the like. Examples of the actuator include a shape memory alloy. Specifically, when a wire made of a shape memory alloy is used as the actuator, the wire contracts in an energized state and relaxes and expands in a non-energized state.

  In addition, as a mode of the power supply to the medical active clip 10 disposed in the body, a battery disposed in the body may be used, or the medical active clip may be wirelessly or wired from the battery disposed outside the body. It is also possible to supply power to the power source. Examples of the wireless power supply to the clip include non-contact power supply by electromagnetic induction using a coil.

  FIG. 4 is a view showing an example of a developed state of the cylindrical portion 11 of the medical active clip 10 according to the embodiment of the present invention. Specifically, FIG. 4 (a) is a front view of the cylindrical portion 11, FIG. 4 (b) is a left side view thereof, FIG. 4 (c) is a right side view thereof, and FIG. 4 (d) is a plan view thereof. FIG. 4 (e) is a bottom view thereof, and FIG. 4 (f) is a rear view thereof.

  FIG. 5 is a view showing an example of a cylindrical state and an open state of the cylindrical portion 11 of the medical active clip 10. Specifically, FIG. 5 (a) is a front view of the cylindrical portion 11, FIG. 5 (b) is a left side view thereof, FIG. 5 (c) is a right side view thereof, and FIG. 5 (d) is a plan view thereof. 5 (e) is a bottom view thereof, FIG. 5 (f) is a rear view thereof, FIG. 5 (g) is a perspective view thereof, and FIG. 5 (h) is a cross section taken along line AA ′ of FIG. 5 (a). FIG.

  The cylindrical part 11 is formed in a polygonal cylindrical shape, and in this embodiment, is formed in a triangular cylindrical shape. As shown in FIGS. 4A to 4F, the cylindrical portion 11 in the unfolded state has a substantially thin plate shape. The medical active clip 10 is attached to an artificial blood vessel or the like in a deployed state. In the unfolded cylindrical portion 11, a mountain fold line LM and a valley fold line LV are provided at specified positions. In detail, the cylindrical part 11 has three parts 11A, 11B, and 11C corresponding to the side wall when in the cylindrical state. The cylindrical part 11 in the unfolded state has a structure in which the part 11A and the part 11B are connected and the part 11B and the part 11C are connected.

As shown in FIG. 4 (a), a valley fold line LV is set at the connecting portion between the portions 11A and 11B, and a valley fold line LV is set at the connecting portion between the portions 11B and 11C. By bending along the fold line LM, as shown in FIG. 5A to FIG. The left and right end portions 11s and 11t of the tubular portion 11 in the unfolded state are joined when in the tubular state.
As a mode of joining the end portions 11s and 11t, the end portions 11s and 11t may be stitched with a thread or the like, or a magnet is provided at each of the left and right end portions 11s and 11t and joined by magnetic force. Alternatively, an engaging portion and an engaged portion may be provided in each of the left and right end portions 11s and 11t, and the engaging portion and the engaged portion may be engaged.

Further, as shown in FIG. 4A, a mountain fold line LM is diagonally set from the upper side to the lower side in each of the part 11A, the part 11B, and the part 11C. In the case of the cylindrical state, as shown in FIGS. 5 (a), 5 (b), 5 (c), 5 (f), and 5 (g), the side wall of the cylindrical portion 11 in the cylindrical state The valley fold line LV is set in each of the part 11A, the part 11B, and the part 11C corresponding to the part. Specifically, the valley fold line LV is defined by the position of one corner on the upper side of the side wall part and the lower side. It is set obliquely between a position shifted by a predetermined distance from the center along the lower side of one corner. When the valley fold line LV is bent, each side wall portion is bent and deformed.
The valley fold line LV may be set obliquely between the position of one corner on the upper side of the side wall and the center on the lower side. The position of the valley fold line LV is set so that the inner cross-sectional area at the time of deformation of the cylindrical portion 11 is an optimum value.

  In this embodiment, a wire made of a shape memory alloy is provided as an actuator so as to contract between one diagonal of each rectangular side wall portion in the cylindrical portion so as to intersect the valley fold line LV. .

FIG. 6 is a diagram illustrating an example of a deformed state (closed state) of the cylindrical portion of the medical active clip. Specifically, FIG. 6A is a diagram showing an example of the shape of the upper end portion of the deformed cylindrical portion, FIG. 6B is a diagram showing an example of the shape of the lower end portion, and FIG. FIG. 6C is a perspective view from above, and FIG. 6D is a perspective view from below.
6 (a) and 6 (c), in the deformed tubular portion, the area surrounded by one opening end (upper side end) is the same as before deformation, and FIG. b) As shown in FIG. 6D, the area surrounded by the other opening end (lower end) is small or zero.

  FIG. 7 is a diagram showing an example of the operation of the medical active clip. Specifically, FIG. 7A is a perspective view showing an example of an open state of the medical active clip, FIG. 7B is a perspective view showing an example of a deformed state (semi-closed state), and FIG. It is a perspective view which shows an example of a deformation | transformation state (closed state).

The wire made of shape memory alloy as the actuator 121 provided on the side wall portion of the tubular portion is relaxed and stretched in a non-energized state, and as shown in FIG. The area is the specified size.
The actuator 121 provided on the side wall portion of the cylindrical portion contracts in the energized state and deforms while the side wall portion is bent at the valley fold line LV as shown in FIGS. To do. Specifically, as shown in FIGS. 7A to 7C, the cylindrical portion 11 is deformed while being twisted, and the distance between the upper end portion and the lower end portion is slightly shortened. In this case, the side wall portion is deformed while the upper end portion side opening portion rotates in a predetermined direction with respect to the lower end portion side while maintaining the shape of the upper end portion side opening portion.

Next, when the shape memory alloy wire as the actuator 121 is in a non-energized state, the wire relaxes and extends. By forming the cylindrical part 11 with a material having reversibility with respect to deformation, the cylindrical part 11 becomes an original cylindrical state as shown in FIG.
In addition, when the cylindrical part of the medical active clip is attached to the artificial blood vessel, the blood pressure in the artificial blood vessel acts as a restoring force so as to open the cylindrical part. By doing so, the cylindrical part 11 will be in an original cylinder state, as shown to Fig.7 (a).

  When the shape memory alloy wire is changed from the energized state to the non-energized state, the tubular portion is shown in FIG. 7A by providing an extending means that extends between the upper end and the lower end of the tubular portion. It may be forced to return to the original cylinder state.

FIG. 8 is a conceptual diagram showing an example of the medical active clip 10 provided with the cover member 150.
The cylindrical portion 11 of the medical active clip 10 is attached so as to cover the outer periphery of the artificial blood vessel 410 (41). Each side wall portion of the cylindrical portion 11 is provided with a wire made of a shape memory alloy as the actuator 121 of the contraction portion 12.
Further, as shown in FIG. 8, a cover member 150 may be provided so as to cover the medical active clip 10. In the present embodiment, the cover member 150 is formed in a bottomed cylindrical shape and has a hollow accommodating portion that accommodates the active clip 10 therein. The cover member 150 has openings 151 and 152 that penetrate an artificial blood vessel or the like. Further, the cover member 150 has an engaging portion 155, and is configured to be openable and closable by the engaging portion 155. When the medical active clip 10 is attached to the artificial blood vessel 410 (41), the cover member 150 is attached. It can be easily installed.

  This cover member 150 partitions between the medical active clip 10 accommodated therein and the body tissue around the cover member 150, and transmits fluctuations due to the operation of the medical active clip 10 to the surrounding body tissue. Can be prevented.

FIG. 9 is a conceptual diagram showing an example of a medical active clip 10 of the forward / reverse phase series type.
Further, as shown in FIG. 9, the cylindrical portion of the medical active clip 10 has a structure in which two cylindrical portions 11G (11) and 11F (11) that are deformed in opposite phases are connected. You may do it. On each side wall portion of the cylindrical portion 11G (11), a wire made of a shape memory alloy is provided on each side wall portion of the cylindrical portion 11G (11) as an actuator 121G (121) of the contraction portion. It is provided to have a different inclination with respect to LV. In addition, a wire made of a shape memory alloy is provided on each side wall portion of the cylindrical portion 11F (11) on each side wall portion of the cylindrical portion 11F (11) as the actuator 121F (121) of the contraction portion. They are provided to have different inclinations with respect to the valley fold line LV.
During the clip operation, in the cylindrical portion shown in FIG. 9, the cylindrical portion 11G (11) and the cylindrical portion 11F (11) are in a reverse phase so that the central portion is twisted with respect to both ends of the cylindrical portion. Deform. That is, the active medical clip shown in FIG. 9 is configured so that one end of the cylindrical portion does not rotate with respect to the other end while maintaining the opening shape of both ends during operation. Yes. For this reason, it is possible to prevent the fluctuation during the clip operation from being transmitted to the surrounding body tissue near both ends with a simple structure.
Further, as shown in FIG. 9, a cover member 150 may be provided so as to cover the positive / reverse phase series medical active clip. By carrying out like this, it can further reduce transmitting the fluctuation | variation by operation | movement of the medical active clip 10 to a surrounding body tissue.

FIG. 10 is a diagram illustrating an example of a cylindrical portion of a medical active clip. Specifically, FIG. 10A is a diagram illustrating an example of an open state of the cylindrical portion, and FIG. 10B is a diagram illustrating an example of a closed state of the cylindrical portion of FIG.
The inventor of the present application actually manufactured a medical active clip and confirmed the operation of the medical active clip. In the present embodiment, the cylindrical portion of the clip is formed of a fluororesin material such as ePTFE (expanded porous PTFE).
The active medical clip in the open state has a cylindrical shape as shown in FIG. 10 (a), and the active medical clip in the closed state has a side wall portion of the cylindrical portion as shown in FIG. 10 (b). Deformed and closed.

The inventor of the present application actually produced a medical active clip and measured the characteristics of the medical active clip.
FIG. 11 shows an example of a medical active clip. As shown in FIG. 11, a medical active clip is provided on a cylindrical member as the artificial blood vessel 41. In addition, in FIG. 11, the mirror (not shown) is arrange | positioned so that the side surface and opening side of the cylindrical part 11 of an active clip can be visually recognized at once.

FIG. 12 is a conceptual diagram showing an example of a characteristic measuring device for a medical active clip.
The characteristic measuring device 50 includes a tank 51 for storing a liquid imitating blood, a pump 52, a pressure gauge 55 (Manometer), and a cylindrical member as the artificial blood vessel 41. The tank 51, the pump 52, and the artificial blood vessel are connected by a pipe 53. The active clip 10 is arranged so as to surround the outer periphery of the artificial blood vessel 41.
The pressure gauge 55 has two pipes 551 and 552. One end portion 551b of the tube 551 is connected to the upstream side of the artificial blood vessel 41, and the other end portion 551a is disposed above it. One end portion 552b of the tube 552 is connected to the downstream side of the artificial blood vessel 41, and the other end portion 552a is disposed above it.
The pressure gauge 55 can measure the pressure difference between the upstream side and the downstream side of the artificial blood vessel 41 based on the height difference h between the water surface 551t in the tube 551 and the water surface 552t in the tube 552.

FIG. 13 is a diagram showing an example of pressure in the artificial blood vessel in each form of the medical active clip. The vertical axis of FIG. 13 shows the pressure difference between the upstream side and the downstream side of the artificial blood vessel, and the horizontal axis shows each form of the medical active clip.
In the case of the above-described active medical clip having a triangular cylindrical portion, the pressure difference is about 0.22 mmHg in the open state (Open), and the pressure difference is about 0.35 mmHg in the half-closed state (Half). In the closed state (Complete), the pressure difference was 0.58 mmHg. In the present embodiment, a slight gap is formed even in the closed state (Complete), and the liquid flows slightly.
As described above, it has been confirmed that the medical active clip can act on the artificial blood vessel in the open state, the semi-closed state, and the closed state to control the flow resistance in the artificial blood vessel.

  Note that the medical active clip is not limited to a triangular cylinder shape, and may be formed in a substantially C shape, for example, as shown in FIG. This substantially C-shaped medical active clip is configured such that a gap is formed between both ends, and the interval can be adjusted. In the state where an artificial blood vessel is disposed between both ends of the substantially C-shaped medical active clip and the interval between the clip ends is reduced, the artificial blood vessel is occluded as shown in FIG. In this state, the same pressure measurement was performed. As a result, the pressure difference between the upstream side and the downstream side was about 0.42 mmHg. As described above, the substantially C-shaped medical active clip as one embodiment of the present invention can act on the artificial blood vessel to control the flow resistance in the artificial blood vessel.

The inventor of the present application conducted an acute animal experiment using a medical active clip. FIG. 14 is a conceptual diagram showing an example of an acute animal experiment using a medical active clip.
As shown in FIG. 14, an artificial pump 501 was connected to an animal heart 500 with a tube 502 and a tube 503. An aorta Ao, a pulmonary artery PA, and an inferior vena cava IVC are disposed in the vicinity of the heart 500 including the left ventricle LVe and the right ventricle RVe.
A bypass operation for providing an artificial blood vessel 41 between the pulmonary artery PA and the inferior vena cava IVC was performed, and the medical active clip 10 was provided so as to surround the outer periphery of the artificial blood vessel 41.

FIG. 15 is a diagram showing an example of an experimental result for a medical active clip. Specifically, FIG. 15A is a view showing an example of the pressure downstream of the artificial blood vessel in the closed state of the medical active clip, and FIG. 15B is a view of the artificial blood vessel in the opened state of the medical active clip. FIG. 15C is a view showing an example of the downstream pressure, FIG. 15C is a view showing an example of the flow rate (volume flow rate) in the artificial blood vessel when the medical active clip is closed, and FIG. 15D is a medical active clip. It is a figure which shows an example of the flow volume (volume flow volume) in the artificial blood vessel in the open state. Specifically, a pressure gauge and a flow meter were provided downstream of the artificial blood vessel 41.
15A and 15B, the vertical axis indicates the pressure Pout (mmHg), and in FIGS. 15C and 15D, the vertical axis indicates the flow rate Flow (L / min). . In each figure of Drawing 15 (a)-Drawing 15 (d), time (s) was shown on the horizontal axis.
The pressure and flow rate change with time, so the pressure and flow rate are extracted from the measured data when the active clip repeats the closed and open states (Occlusion) and when it is in the open state (pass through). The maximum value, minimum value, and average value of each are arranged in time series.

When a medical active clip repeats a closed state and an open state, the pulsation of blood pumped by the living body changes in response to the state change, and the maximum and minimum values of pressure and flow rate are compared with the open state. The fluctuation is increasing. When the medical active clip is in a closed state, the flow resistance of the medical active clip increases, the blood flow from the vein connected to the inflow side of the medical active clip decreases, and the inflow of the medical active clip The volume in the side venous vessels increases. Due to the large compliance of the venous blood vessels, there is almost no increase in the pressure of the vein on the inflow side of the medical active clip when the medical active clip is closed, but the medical active clip is closed at this time. When changing from open to open, blood accumulated in the vein flows into the pulmonary artery downstream of the medical active clip with an increase in flow rate. Therefore, as shown in FIG. 15 (c), when the medical active clip repeats the closed state and the open state, the flow rate of the flow passing through the medical active clip increases with time, and is stored in the vein and stored in the pulmonary artery. It can be seen that fluctuations in the inflowing blood flow are larger than the flow rate when the medical active clip shown in FIG. 15D is in the open state.
In the acute animal experiment according to the present embodiment, in a state where the chest is opened, the breathing operation for forced ventilation of the lung is performed by applying external pressure such as pressurized air and oxygen from the outside, Since pressure and flow are measured, pressure fluctuations associated with breathing in the downstream pulmonary circulation of the active medical clip are positive for both exhalation and inspiration compared to the case of measuring with spontaneous breathing with the chest cavity closed. It changes in the pressure state, and the characteristics of pressure fluctuation and flow fluctuation are different from the characteristics of spontaneous breathing in the closed state.

  FIG. 16 is a conceptual diagram illustrating an example of respiration detection by the respiration detection device. Specifically, FIG. 16 (a) is a diagram showing an example of a respiration detection device arranged on the chest of an animal, and FIG. 16 (b) shows a change with time of acceleration detected by the respiration detection device shown in FIG. 16 (a). FIG. 16C is a diagram showing an example of the corresponding respiratory signal, FIG. 16C is a diagram showing an example of the respiratory detection device placed in the abdomen, and FIG. 16D is detected by the respiratory detection device shown in FIG. It is a figure which shows an example of the respiration signal according to the time change of an acceleration. In FIG. 16B and FIG. 16D, the vertical axis represents acceleration and the horizontal axis represents time. The arrow indicates the timing of the small body movement from the expiration period to the inspiration period.

As a result of the measurement, it was confirmed that body motion due to respiration can be detected by an acceleration sensor type respiration detection device. It was also found that body movement due to respiration can be detected with high accuracy when the respiration detection device is arranged in the abdomen rather than the chest. This is because the fluctuations of the ribs and the like are relatively large according to the breathing motion, and the body movement due to breathing can be detected with high accuracy by detecting the large fluctuations.
The respiration detection device generates a respiration signal based on the change in acceleration of body motion according to the respiration described above, and transmits the respiration signal to the medical active clip.

As described above, the medical active clip 10 according to the embodiment of the present invention reduces the backflow of blood in the artificial blood vessel 41 that joins the inferior vena cava and the pulmonary artery. This medical active clip 10 is disposed so as to surround the outer periphery of the artificial blood vessel 41 and includes a contracting portion 12 as a contracting means for reducing the cross-sectional area in the artificial blood vessel 41. The contraction unit 12 as the contraction unit repeats contraction by a drive circuit 103 (control unit 101 as a control unit) as a drive unit that is driven according to a breathing signal. For example, the respiration signal is generated by the respiration detection device 20 disposed on the body surface of the human body.
For this reason, with a simple configuration, the cross-sectional area in the artificial blood vessel can be reduced by the contracting means during the expiration period according to the respiratory signal, the flow resistance can be increased, and the backflow of blood in the artificial blood vessel can be reduced. be able to. In addition, since contraction by the contraction means is not performed in the inspiration period according to the respiratory signal, the flow resistance in the artificial blood vessel is lowered, and the blood flow from upstream to downstream in the artificial blood vessel is not hindered.
In addition, as a contraction means, you may have a cylindrical part and you may have a substantially C-shaped member.

Further, in the medical active clip 10 according to the embodiment of the present invention, the contraction portion 12 as the contraction means includes a cylindrical portion 11 surrounding the outer periphery of the artificial blood vessel, and an actuator for contracting the cylindrical portion 11 in the radial direction. (Actuator). The actuator contracts the cylindrical portion 11 in the radial direction by driving the driving means such as the driving circuit 103 and the control unit 101. Specifically, the actuator contracts in the radial direction with respect to the cylindrical portion 11 in accordance with the respiratory signal. For example, a wire made of a shape memory alloy is used as the actuator.
For this reason, the cylindrical portion 11 is contracted in the radial direction by the actuator with a simple configuration, thereby reducing the cross-sectional area in the artificial blood vessel in the expiration period according to the respiratory signal and increasing the flow path resistance. Can do.

In the medical active clip 10 according to the embodiment of the present invention, the cylindrical portion 11 is formed in a polygonal cylindrical shape, and the actuator contracts between one diagonal of the rectangular peripheral wall portion in the cylindrical portion 11. It is configured as follows.
For this reason, it deform | transforms so that the cylindrical part 11 of the medical active clip 10 may be twisted, and it shrinks slightly in an axial direction, and can reduce the cross-sectional area of the cylindrical part 11 easily.
Further, by adopting a triangular cylindrical shape as the cylindrical portion 11, the cylindrical portion 11 can be easily modified as described above with a simple structure. In addition, by adopting the tubular portion 11 having a triangular tubular shape, the deployed clip is wound around the outer circumference of the artificial blood vessel at the time of surgery, and the end portion is sewn with a thread so as to be in a tubular state. Thus, it can be easily attached to an artificial blood vessel.

  Further, the actuator of the medical active clip 10 according to the embodiment of the present invention is formed of a shape memory alloy. For example, a wire-shaped shape memory alloy contracts when energized and relaxes and expands when de-energized. For this reason, the medical active clip 10 which can perform the said operation | movement with a simple structure can be comprised.

  In the above-described embodiment, the medical active clip has a mode in which the cross-sectional area of the cylindrical member as an artificial organ such as an artificial blood vessel is reduced according to a respiratory signal, but is not limited to this mode. For example, the medical active clip may be configured to reduce the cross-sectional area of a cylindrical member as an artificial organ in synchronization with a heartbeat signal or a blood pressure signal.

Moreover, in the said embodiment, although the medical active clip was provided in the artificial blood vessel which joins between the inferior vena cava and the pulmonary artery, it is not restricted to this form. The medical active clip may be provided in, for example, a cylindrical artificial organ such as an artificial esophagus, an artificial trachea, and an artificial anus, or an actual human organ. Moreover, in the said embodiment, although it was the aspect contracted according to a respiration signal, the aspect which contracts according to the signal other than that may be sufficient.
In other words, in this case, the medical active clip used for the cylindrical artificial organ is attached to the cylindrical artificial organ (artificial blood vessel, artificial esophagus, artificial airway, artificial anus, etc.) and arranged so as to surround the outer periphery thereof. And a contraction means for reducing a cross-sectional area in the cylindrical artificial organ, the contraction means including a polygonal cylindrical cylindrical portion surrounding an outer periphery of the cylindrical artificial organ, and a radial direction of the cylindrical part. And an actuator for contracting. The actuator is configured to contract between one diagonal of the rectangular peripheral wall portion in the cylindrical portion.

  The medical active clip may be formed integrally with a cylindrical member such as an artificial blood vessel.

  Hereinafter, the configuration and effects of the medical active clip according to the embodiment of the present invention will be described together.

-Suppression of reverse flow The active clip for medical use according to an embodiment of the present invention attaches a back flow from an artificial blood vessel connected to a pulmonary artery to the inferior vena cava from the outside to reduce the cross-sectional area of the artificial blood vessel lumen. Thereby increasing the line resistance. The lumen cross-sectional area can be reduced by contracting and twisting the inside of the clip attached to the outside of the artificial blood vessel.

・ Opening after backflow suppression With the medical active clip according to the embodiment of the present invention, backflow suppression by increasing vascular resistance can be realized, and when structural contraction is actively relaxed, the cross-sectional area of the blood vessel is increased and The forward resistance from the vena cava to the pulmonary artery can be reduced.

-Reduction of damage and damage to the tissue around the artificial blood vessel The medical active clip according to the embodiment of the present invention can be implanted into the thoracic cavity even for a patient with a small physique, and pressure on the organ around the artificial blood vessel is reduced. It is a small small volume clip.

-Miniaturization by using micro actuators The active clip for medical use according to the embodiment of the present invention has a structure using shape memory alloy fibers, which makes it easy to implant in the body and can be used even by small children. is there.

-Suppression of vascular regurgitation synchronized with respiration The medical active clip according to an embodiment of the present invention can actively reduce the diameter of the blood vessel when the intrathoracic pressure increases by synchronizing the phase of respiration non-invasively from outside the body.

-System using a respiration detection device The respiration detection device installed at a predetermined position outside the body, such as on the thorax or on the abdominal wall, has a relatively small volume of medical active clip for implantation in the body.

Respiratory timing control The active clip for medical use according to the embodiment of the present invention has no direct contact with circulating blood, so there is no problem of thrombus formation and blood compatibility with respect to the structural design, and these design problems are important. Unlike some blood pumps, control can be performed at the necessary timing when necessary.

  Conventionally, it is impossible to attach a large device outside the artificial blood vessel in heart surgery for children with small physique, and in lower vena cava-pulmonary artery bypass surgery for congenital heart disease treatment, Venous regurgitation is considered an inevitable phenomenon that occurs with this operation. The medical active clip according to the embodiment of the present invention can solve these blood flow changes by actively changing the artificial blood vessel resistance.

  Moreover, at the time of an operation, it is only necessary to add the operation | work which mounts the medical active clip which concerns on embodiment of this invention on an artificial blood vessel to the surgical technique using an artificial blood vessel.

  In addition, by using the medical active clip according to the embodiment of the present invention, the change in the blood flow direction from the vein to the pulmonary artery, which fluctuates with respiration, is in a state in line with the physiological blood flow expected by the operation. Can be maintained. In the hemodynamics of a living body, the blood flow from the pulmonary artery to the vena cava is not physiological, and the unidirectional flow from the vein to the pulmonary artery is a physiological blood flow.

  Further, by using the medical active clip according to the embodiment of the present invention, it is possible to reduce the backflow from the pulmonary circulation to the vena cava, which cannot be controlled only by the conventional surgical technique, and non-physiological from the lung. It is possible to reduce the venous pressure by reducing the constant increase of the vena cava volume caused by the reverse flow.

  In addition, the increase in venous pressure downstream of peripheral organs suggests that, for example, when increased venous pressure in the liver occurs, cirrhosis with decreased liver function may occur in the late stage after surgery. In addition, by using the medical active clip according to the embodiment of the present invention, it is possible to reduce the backflow from the pulmonary artery to the vein due to respiratory fluctuation, and to prevent the deterioration of the peripheral organ function.

  Further, by using the medical active clip according to the embodiment of the present invention, veins from the pulmonary artery that fluctuate not only during steady breathing movement but also during pulmonary expansion and contraction movement caused by vocalization or the like in daily life. The backflow can be adjusted.

  In addition, by using the medical active clip according to the embodiment of the present invention, the activity of the medical active clip promotes blood flow accompanying the ventilation of the lung from the vena cava to the pulmonary artery, which is expected as a physiological function. It is possible to reduce the backflow from the pulmonary artery to the aorta without obstructing.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and there are design changes and the like without departing from the gist of the present invention. Is included in the present invention.
Further, the embodiments described in the above drawings can be combined with each other as long as there is no particular contradiction or problem in the purpose and configuration.
Moreover, the description content of each figure can become independent embodiment, respectively, and embodiment of this invention is not limited to one embodiment which combined each figure.

4 ... Blood 10 ... Active medical clip (clip)
DESCRIPTION OF SYMBOLS 11 ... Cylindrical part 12 ... Contraction part 20 ... Respiration detection apparatus 21 ... Acceleration detection part 22 ... Communication part 23 ... CPU (control circuit)
30 ... Heart 41 ... Artificial blood vessel (tubular member)
101 ... Control unit (CPU)
DESCRIPTION OF SYMBOLS 102 ... Communication part 103 ... Drive circuit 121 ... Actuator (shape memory alloy wire etc.)
150 ... Cover member LM ... Mountain fold line LV ... Valley fold line

Claims (6)

A medical active clip for reducing blood backflow in an artificial blood vessel joining the inferior vena cava and the pulmonary artery,
The medical active clip is disposed so as to surround the outer periphery of the artificial blood vessel, and includes contraction means for reducing a cross-sectional area in the artificial blood vessel, and the contraction means repeats contraction by a driving means that is driven according to a respiratory signal. An active clip for medical use. The contraction means includes a cylindrical portion surrounding an outer periphery of the artificial blood vessel,
The medical active clip according to claim 1, further comprising an actuator for contracting the cylindrical portion in a radial direction. The cylindrical portion is formed in a polygonal cylindrical shape,
The medical active clip according to claim 2, wherein the operating element is configured to contract between one diagonal of the rectangular side wall portion in the cylindrical portion.   The medical active clip according to claim 3, wherein the cylindrical part is formed in a triangular cylindrical shape.   The medical active clip according to any one of claims 2 to 4, wherein the actuator is made of a shape memory alloy. A medical active clip used for a cylindrical artificial organ,
The medical active clip is attached to a cylindrical artificial organ, is disposed so as to surround the outer periphery thereof, and includes contraction means for reducing a cross-sectional area in the cylindrical artificial organ,
The contraction means is a polygonal cylindrical part surrounding the outer circumference of the cylindrical artificial organ;
An actuator for contracting the cylindrical portion in a radial direction,
The active clip for medical use, wherein the actuator is configured to contract between one diagonal of the rectangular peripheral wall portion of the cylindrical portion.