WO2002004066A1

WO2002004066A1 - Body-buried electrode

Info

Publication number: WO2002004066A1
Application number: PCT/JP2001/005507
Authority: WO
Inventors: Tsuyoshi Shoji; Yoshitaka Oku
Original assignee: Wada, Hiromi; Ohnaka, Kenji
Priority date: 2000-07-12
Filing date: 2001-06-27
Publication date: 2002-01-17
Also published as: JP2002017872A; JP4169460B2; AU2001266336A1

Abstract

An electrode, comprising a conductor (2) and a rubber insulator (3) covering the conductor, the insulator further comprising a holding part (4) having a through-hole capable of generally holding nerve and an opening formed on one side of the through-hole in radial cross section, an extension part (5) extending from the other side of the holding part, an upper jaw (6) extending forward from the upper edge of the opening, having a thicker tip, and forming a small hole at the tip thereof, and a lower jaw (7) extending forward from the lower edge of the opening, wherein the conductor passes through the inside of the extension part, the lower end of the conductor is exposed to the outside from the end of the extension part, and the upper end is exposed to the inside of the through-hole, whereby the electrode buried in a body at a low stress, particularly, a diaphragm pacing electrode buried at a low stress under a thoracoscope can be formed.

Description

Description implantable electrode

INDUSTRIAL APPLICABILITY The present invention belongs to an implantable electrode in the body, and is particularly suitably used as a thoracoscopic implantable, diaphragm-based pacing electrode by electrical stimulation. Background art

Diaphragmatic pacing, which provides functional electrical stimulation of the phrenic nerve, is primarily central alveolar hypoventilation syndrome (a syndrome of hypercapnia despite normal pulmonary function; when sleeping) Hypoventilation worsens, meaning that it cannot take in oxygen and produce carbon dioxide) and high myelinjury (

C6; {Sixth or more from the top of the myelinated spinal cord has been damaged by accident or tumor).

All of these procedures stimulate the phrenic nerve or diaphragm to ventilate the patient, who needs assistance from the ventilator, to make the breathing artificial, and thereby withdraw from the ventilator. I have. The ventilator interferes with the functions of the mouth, such as vocalization and eating, and is not portable and has a limited range of action.

Conventionally, as a diaphragm basing electrode, a type sewn to the phrenic nerve (SURGICAL CLINICS OF NORTH AMERICA, VOL.60, NO.5, OCTOBER 1980, P1055) and a type sewn directly to the diaphragm (IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL .44, NO.10, OCTOBER 1997, P921).

However, it is not as widespread as the heart pacemaker. One of the reasons is that the electrode implantation procedure involves thoracotomy. It can be considered invasive (stress on the human body).

Therefore, one object of the present invention is to solve this problem and to provide an electrode which can be implanted in the body in a minimally invasive manner, in particular, a diaphragm pacing electrode which can be implanted in a minimally invasive manner under thoracoscopy. Disclosure of the invention

In order to solve the problem, an implantable electrode according to the present invention provides an electrode including a conductor and a rubber insulator covering the conductor, wherein the insulator is

A gripper having a through-hole capable of gripping a nerve, and having an opening formed on one side of a radial cross section of the through-hole;

An extension that extends longer than the other side of the grip,

An upper beak that extends forward from the upper edge of the opening, has a thicker tip, and has a small hole formed at the tip,

With a lower beak extending forward from the lower edge of the opening,

The conductor passes through the extension, and the lower end is exposed outside the end of the extension, and the upper end is exposed in the through hole.

When using the implanted electrode in the body, a thin wire such as a thread is passed through a small hole, and the thread is pulled inside the body to open the upper and lower beaks. Next, the beak is used as a guide to move the opening of the grasping part to the nerve, the nerve is inserted into the through hole from the opening, and the upper and lower beaks are fixed to each other by fixing means such as clips. And can grasp nerves. Since the insulator is made of rubber, the opening and closing of the upper and lower bills and the expansion and contraction of the opening are performed by elastic deformation of the insulator. Since the upper end of the conductor is exposed inside the through hole, the nerve can be stimulated by applying a current to the lower end of the conductor that extends outside from the end of the extension. At present, thoracoscopic surgery is widely used as a surgical technique for various thoracic diseases. According to the electrode of the present invention, the nerve can be grasped only by fixing the upper and lower beaks to each other by a fixing means such as a clip, so that neither sewing nor touching the electrode is required. Therefore, it is minimally invasive. Since it is an easy procedure for a thoracic surgeon who is experienced in thoracoscopic surgery to perform electrode implantation, it is suitable for various treatments such as diaphragm pacing if clinical application is possible. If a sheet with a large number of irregularities in the surface direction is attached to one or both of the lower surface of the lower beak, the sheet serves as a non-slip for the above-mentioned clip or other fixing means, and the fixing means is It is preferable because it does not come off from the beak.

In addition, if a reinforcing material is attached to one or both of the lower surface of the upper beak and the upper surface of the lower beak, the beaks maintain a predetermined shape even during the work of inserting the nerve, so that the nerve penetrates the nerve. It is preferable because it is easy to fit into the hole or fix the upper and lower beaks to each other by the fixing means.

Further, the shape of the conductor is such that the conductor is exposed from the base of the beak upward through the thick portion of the grip portion to the inside of the through hole from the extension portion, and is folded back to the bottom of the beak along the wall surface of the through hole. Preferably it is extended. This allows the nerve to be in contact with the nerve at any position on the wall of the through-hole, and electrical connection is ensured. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing the implanted electrode of the embodiment, FIG. 2 is a longitudinal sectional view of the electrode, FIG. 3 is a rear view of the electrode, FIG. 4 is a front view of the electrode, and FIG. Fig. 6 shows the electrode of the embodiment. And diaphragm base is Dara off showing the time course one single longitudinal carbon dioxide partial pressure (paC0 _2). BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an implantable electrode according to the embodiment, FIG. 2 is a longitudinal sectional view, FIG. 3 is a rear view, and FIG. 4 is a front view.

The electrode 1 is composed of two conductors 2 and 2 and a silicon rubber insulator 3 covering the conductors 2 and 2. The conductor 2 is formed by soldering a three-piece platinum wire having a diameter of 0.03 mm and a stainless steel wire.

The insulator 3 is composed of a gripper 4, an extension 5, an upper beak 6, and a lower beak 7. The grip portion 4 has a through hole 41 having a thickness of 2 mm, a width of 7 mm, and an inner diameter similar to that of a nerve such as the phrenic nerve, for example, a diameter of about 3 mm. An opening 42 is formed on one side of the radial cross section. The extension portion 5 has an outer diameter of 2 mm and extends to a length of 300 mm from a position different from the opening 42 of the grip portion 4. The upper beak 6 extends 5 mm forward with a thickness of 1 mm from the upper edge of the opening 42, has a tip approximately 2 mm thick, and has a small hole 61 having a diameter of 0.5 mm formed at the tip. ing. A sheet 62 made of reticulated silicon is embedded in the lower surface of the upper beak 6. The lower beak 7 extends forward with a substantially uniform thickness of 0.5 mm from the lower edge of the opening 42, and a lower sheet is embedded with a sheet 71 of the same quality as the sheet 62. .

The conductor 2 passes through the extension 5 in the length direction, and its lower end is exposed to the outside from the end of the extension 5 and is connected to the connector 8. On the other hand, the upper end of the conductor 2 passes through the thick part of the gripper 4 so as to bypass the through-hole 41, reaches the base of the beak 6, and then goes out into the through-hole 41 to be folded. Then, along the inner periphery of the through hole 41, it reaches near the base of the lower beak 7. Of the conductive wire 2, the platinum wire portion is located on the upper side, and the stainless steel wire portion is located on the lower side, and both are joined near a boundary between the grip portion 4 and the extension portion 5. The stainless steel wire portion is formed into a thread-like shape and Teflon-coated, and has a diameter of 0.25 mm. The conductors 2 and 2 are separated from each other so as not to short-circuit each other, and the interval between the platinum wire portions exposed in the through holes 41 is

It is set to 3 mm.

The thread color edge 3 may be formed by integrally molding the grip portion 4, the extension portion 5, and the upper and lower beaks 6 and 7 by a normal rubber molding technique, or may fuse the respective components after separate molding. In the case of integral molding, fix the conductors 2 and 2 in a mold and pour the rubber. In the case of separate molding, the gripping portion 4 is processed into a circular cross section with a silicon rubber sheet and a small hole for passing the conductor 2 is formed. Then, the conductive wire 2 is passed through a silicon tube, and the tube is heat-softened to form an extended portion 5, which is thermally fused to the grip portion 4.

When using the electrode 1 to be implanted in the body, a thread is passed through the small hole 61 and the thread is pulled inside the body to open the upper and lower bills 6 and 7. Next, using the beaks 6 and 7 as guides, the opening of the grasping part up to the nerves not shown

The nerve can be gripped by moving 42 and inserting the nerve into the through-hole 41 from the opening 42, and then fixing the upper and lower beaks 6 and 7 to each other with a clip. All of these operations are performed under thoracoscopy. The grasped nerve contacts the platinum wire portion of the conducting wire 2 in the through hole 4 1.

Since the insulator 3 is made of silicon rubber, the opening and closing of the upper and lower bills 6 and 7 and the expansion and contraction of the opening 42 are performed by the elastic deformation of the insulator 3. However, since the sheet 61 is provided on the lower surface of the upper beak 6, it is not excessively deformed. Since the upper end of the wire 2 exposed inside the through hole is in contact with the nerve, connect the connector to a nerve stimulator outside the body. Can stimulate nerves.

An example of the above-mentioned clip is a rig clip ERCA, which is released by Johnson & Johnson Corporation. The top end of the upper beak 6 is formed to be thick, and the lower end of the lower beak 7 is provided with a sheet 71. It stops. Therefore, there is no need to worry about the clip coming off during nerve stimulation. Micro connector A-2P (manufactured by Unique Medical Inc.) is exemplified as connector-18.

The shape of the conductor is not limited to the above-described conductor 2, and the upper end of the conductor 2 may protrude directly from the extension 5 into the through hole 41 as shown in the cross-sectional view of FIG. 5, or may be replaced with a wire. A foil may be used and this may be lined with the wall surface of the through hole 41. In order to confirm the effect of the present invention, a living test was conducted using five mongrel dogs (15-25 kg). Olympus video monitors and Olympus video thorascopes (a metal tube about 5 mm in diameter and about 30 cm in length, with a CCD camera and light source at the tip) ), 5 mm port, 7 mni port, and thoracoscopic forceps. The procedure is as follows.

[Experimental procedure]

1. Premedication for intramuscular injection of ketamine hydrochloride as a general anesthetic (trade name for intramuscular injection of keiyaral, manufactured by Sankyo) Intramuscular injection of 10 mg / kg, transfer to the operating table, and blood sampling from right femoral artery Then measure spontaneous breathing and blood gas partial pressure in room air. Shaving the forelimbs (forelimbs) (shaving), securing intravenous lines (starting infusion), intravenous pentobarbital salt (trade name Nembutal, manufactured by Dainippon Pharma Co., Ltd.) 10 mg / kg intravenously Injected and introduced. Anesthesia was maintained by inhalation of an inhaled anesthetic, Yaguchi Tan (Flosen, trade name, manufactured by Takeda Pharmaceutical). 2. Orally intubate the endotracheal tube and start artificial respiration. In the supine position (back up), the stomach was shaved to expose the right femoral artery, an arterial line was inserted, and blood pressure, heart rate, and blood gas were monitored. Blood gas from bilateral lung ventilation was collected from the arterial line and measured.

3. Shaving the neck (neck), exposing the trachea of the neck and making a tracheostomy. Remove the endotracheal tube once orally intubated, re-pipe the tube through the tracheal incision, and observe the tube with a bronchoscope to remove the tube from the left main bronchus (left side where the trachea branches right and left) Left one lung Intubate. This allows only the left lung to ventilate.

4. Position the patient in left-side-down position (position lying on the left side), shaving the right chest, opening a wound about 2 cm in the right chest, and connecting 5πιιιι and 2 ports of 7iM between the right ribs. (Total of 4 places), observe the inside of the thoracic cavity with a video thoracoscopy, exclude (push out) the right lung to the caudal side (lower side), check the superior vena cava, Check the right phrenic nerve running on top).

5. Peel off the superior vena cava using thoracoscopic forceps, taking care not to damage the right phrenic nerve. A 4-0 nylon thread is passed through the small hole 61 of the electrode 1 of the above embodiment.

6. Insert the electrode 1 into the thoracic cavity at the point where it is sufficiently detached, pull the thread passing through the small hole 61 to open the upper and lower beaks 6 and 7, and grasp the phrenic nerve. When gripped, fix the beaks 6 and 7 using the rig clip ER220. Check the fixation and remove the nylon thread.

7. Take the connector 1 of electrode 1 out of the body through a subcutaneous tunnel (a tunnel created under the skin), connect one of the conductors 2 to ground, and connect the other one to the electric stimulator SEN- manufactured by Nihon Kohden. 330 Connect to the cathode of 1 and deliver electrical stimulation, and thoracoscopically check for contraction of the phrenic nerve. In other words, check the movement of the muscle (diaphragm) with the video mon itor. The anode of the stimulator is connected to the skin as an indifferent electrode. 8. Pull out the intubation tube several centimeters, return the end of the tube to the trachea, stop ventilation of only the left lung, remove 5mni, 7mm port for both lung ventilation, and insert a 20ir trocar from one port entry. Connected to the Heimlich valve (removing the right lung, which is now deflated, by letting the air that has entered the chest cavity escape the body). The remaining port entry was sutured closed and blood gas was measured in both lung ventilation. Remove the ventilator and base the phrenic nerve while monitoring the ventilation flow rate and volume without adding room air, or oxygen. The pacing condition is [main interval: 3sec (RR20 / min)

, Interval: 20 ms, dur at ion (1 time): 150 sec, train (continuous): 65 times, stimulation was twice the threshold (about 2 V). During this period, the anesthesia of the experimental dog was maintained by intravenous injection of nembutal (Ventvalpital, manufactured by Dainippon Pharma Co., Ltd.), and spontaneous respiration was completely eliminated.

9. Measure the carbon dioxide partial pressure (paC ()) of the blood gas at 5, 15, 30, 45, and 60 minutes (minutes) after the start of basing. The measurement results are shown in FIG.

[Evaluation]

In the blood gas data, there was a gradual increase in pC (increase in carbon dioxide in the blood) after 60 minutes of pacing (see Figure 6), which included neuromuscular fatigue (diaphragm nerve and diaphragm electrodes). Stimulation causes fatigue and slows down the movement of the diaphragm), but bilateral pacing also needs to be considered. After implanting the electrodes, start basing 12 to 14 days later, and gradually increase the paching time from 2-3 minutes per hour to several minutes every day while monitoring neuromuscular fatigue. Non-fat igue ing fibers, fatigue-registant muscle fibers that do not cause fatigue in the diaphragm during this schedule. fibers) Go. It is considered that the increase of p C 0 ₂ is inevitable as one-sided singing in this experiment. However, if evaluations based on strict schedules, such as those currently performed in clinical cases, are performed to prevent neuromuscular fatigue, the potential for clinical application can be expected. Industrial applicability

According to the present invention, an electrode can be implanted under thoracoscopy. As an expected effect, the indication of diaphragm paging has spread to cases that cannot withstand general surgical invasion, and has been used in many patients with ventilatory insufficiency who had been tied to a ventilator and had become bedridden. This may include withdrawing from ventilators, closing tracheal incisions, and opening the way for return to social activity. Electrode stimulation is expected to be applied not only to the phrenic nerve but also to multiple organs in the future.

Claims

The scope of the claims

1. An electrode comprising a conductor and a rubber insulator covering the conductor, wherein the insulator is

An extension that extends longer than the other side of the grip,

With a lower beak extending forward from the lower edge of the opening,

The implantable electrode according to claim 1, wherein the conductor passes through the extension, a lower end of the conductor is exposed outside the end of the extension, and an upper end is exposed in the through hole.

2. The electrode according to claim 1, wherein a sheet having a large number of irregularities is attached to one or both of an upper surface of the upper beak and a lower surface of the lower beak.

3. The electrode according to claim 1, wherein a reinforcing material is attached to one or both of a lower surface of the upper beak and an upper surface of the lower beak.

4. The conductor is exposed in the through-hole from the base of the upper beak through the thick part of the grip from the extension, and is folded back down to the base of the beak along the wall of the through-hole. 2. The electrode according to claim 1, wherein the electrode extends.

5. The electrode according to claim 1, wherein the insulator is made of silicon rubber.

6. The electrode according to any one of claims 1 to 5, wherein the grip has a through-hole having an inner diameter substantially equal to that of the phrenic nerve.

7. The method according to claim 1, wherein the exposed portion of the upper end of the conductor is made of platinum. An electrode according to any of the above.

8. The conductor according to any one of claims 1 to 6, wherein the conductor comprises an upper portion made of a platinum wire and a lower portion made of a stainless steel wire, and these are joined near a boundary between the grip portion and the extension portion. electrode.

9. The electrode according to any one of claims 1 to 6, wherein the conductor is made of a foil, and an exposed portion at an upper end thereof is lined with a wall surface of a through hole of the grip portion.