WO2007145473A1

WO2007145473A1 - Implantable diaphragm stimulator and breath pacemaking device comprising the same

Info

Publication number: WO2007145473A1
Application number: PCT/KR2007/002874
Authority: WO
Inventors: Y. Jay Chang; Dong Hyuk Lee; Hee Chan Kim; Hyun Jib Kim; Choong Hyo Kim
Original assignee: Material Solutions Technology Co., Ltd.
Priority date: 2006-06-14
Filing date: 2007-06-14
Publication date: 2007-12-21
Also published as: KR20070119163A; KR100845464B1

Abstract

There is provided an implantable diaphragm stimulator comprising a signal receiving unit which wirelessly receives an electrical stimulation signal from outside of a body and demodulates the received stimulation signal, and a stimulation signal transferring unit which directly transfers the stimulation signal demodulated by the signal receiving unit to the motor point of the diaphragm. The diaphragm stimulator according to the present invention receives an electrical stimulation signal from an extracorporeal stimulation generating unit and transfers the stimulation signal directly to the motor point of the diaphragm. The diaphragm stimulator of the present invention ensures safe operation and effectively solves the problem of insanitariness and risk of disconnection of devices.

Description

IMPLANTABLE DIAPHRAGM STIMULATOR AND BREATH PACEMAKING DEVICE COMPRISING THE SAME

Technical Field

[1] The present invention relates to a breath pacemaking device, more particularly to an implantable breath pacemaking device that helps the normal breathing of patients with respiratory disorders by electrically stimulating the diaphragm. Background Art

[2] Artificial respirators are used to help patients who suffer from breathing insufficiencies due to spinal cord injury (SCI) or central alveolar hyperventilation (CAH). Particularly, in diaphragmatic disorder, electrical stimulation is used to assist the motion of the diaphragm.

[3] The diaphragm is a respiratory organ located inside the ribs. As the diaphragm moves up and down, the pressure inside the chest cavity changes. Particularly, it provides cavities for accommodate lungs and heart. The diaphragm is comprised of tendons and muscles. The contraction of diaphragmatic muscles decreases air pressure inside the lungs, resulting in inhalation. Conversely, the relaxation of the diaphragmatic muscles results in exhalation. If the contraction and the relaxation of the muscles become abnormal due to diaphragmatic disorder, breathing insufficiencies occur.

[4] To help the breathing of the patients with diaphragmatic respiratory disorder, a device that periodically contracts the diaphragm by giving electrical stimulation to the phrenic nerve has been proposed.

[5] Referring to Fig. 1, in the conventional diaphragm stimulator, an electrical signal is transmitted from a signal receiver (20) implanted in a body through a wire (22) to electrodes (24). Then, electrical stimulation signal is transmitted to a phrenic nerve (16) of the patient to aid the motion of the diaphragm. In order to transmit the stimulation signal to the phrenic nerve (16) through the electrodes (24), chest cavity is cut open to find the phrenic nerve (16) from a nerve fascicle (14) that connects some parts of a spinal cord (12) to the diaphragmatic muscles. Such conventional diaphragm stimulators and operations require surgical opening of the chest cavity around the neck by about 5-7 cm to find the nerve fibers connected to the diaphragm. In this procedure, other nerves may be damaged and an unsightly scar remains around the neck.

[6] Further, the conventional diaphragm stimulator or artificial respirator have many problems including insanitariness, risk of disconnection of devices, olfactory sense damage and the like and thus are restricted to be used by the patients with respiratory disorder.

Disclosure of Invention

Technical Problem

[7] An object of the present invention is to provide a breath pacemaking device that can be implanted more stably and can be used for an extended period of time.

[8] Another object of the present invention is to provide a new diaphragm stimulator which can be implanted in the body more easily and is effective in aiding the diaphragmatic contraction and relaxation.

[9] Still another object of the present invention is to provide a new breath pacemaking device which is simple in construction, easy to manufacture and economically available to the patients. Technical Solution

[10] According to an aspect of the present invention, there is provided an implantable diaphragm stimulator comprising: an intracorporeal signal receiving unit which wirelessly receives an electrical stimulation signal from outside of a body and demodulates the received stimulation signal; and a stimulation signal transferring unit which directly transfers the stimulation signal demodulated by the intracorporeal signal receiving unit to a motor point of a diaphragm.

[11] In the implantable diaphragm stimulator, the intracorporeal signal receiving unit may preferably comprise a coil for receiving an electrical stimulation signal from outside of a body, a circuitry for demodulating the received stimulation signal and a magnet for a non-contact fixation with an external device.

[12] The stimulation signal transferring unit comprises at least one contact point that directly contacts a motor point of the diaphragm and electrically transfers the stimulation signal. Preferably, the stimulation signal transferring unit comprises two contact points for an active electrode and a reference electrode. Preferably, the stimulation signal transferring unit comprises a fixation wing for fixing the contact points onto which the contact points are exposed on a surface of the fixation wing and directly transfer the electrical stimulation signal to the motor point of the diaphragm.

[13] Preferably, the intracorporeal signal receiving unit and the stimulation signal transferring unit are connected each through a wire coated with a biocompatible material. The biocompatible coating material may be a silicone based biocompatible polymer but is not limited thereto. Preferably, the intracorporeal signal receiving unit is protected by a biocompatible case. In that case, a biocompatible material may be filled inside the case.

[14] In another aspect of the present invention, there is provides a breath pacemaking device comprising: an implanted part which comprises an intracorporeal signal receiving unit that wirelessly receives an electrical stimulation signal from outside of a body and demodulates the received stimulation signal and a stimulation signal transferring unit that directly transfers the stimulation signal demodulated by the intra- corporeal signal receiving unit to a motor point of the diaphragm; and an external part which comprises a circuitry that generates an electrical stimulation signal to be transferred to the implanted part, a controller that controls the strength, duration and interval of the electrical stimulation and a display that visually displays the electrical stimulation.

[15] In the breath pacemaking device according to the present invention, the stimulation signal transferring unit comprises at least one contact point that directly contacts a motor point of the diaphragm and electrically transfers the stimulation signal. The external part may comprise a stimulation signal transmitting unit which transmits the electrical stimulation signal to the implanted part. In this case, the stimulation signal transmitting unit preferably comprises a coil for transmitting the electrical stimulation signal and a magnet for a non-contact fixation with the intracorporeal signal receiving unit.

[16] In addition, the breath pacemaking device according to the present invention may further comprise a power supply such as removable built-in battery, external charging apparatus, etc.

[17] When implanted in the human body, the implantable diaphragm stimulator according to the present invention helps the patient with respiratory disorder to breathe normally by transferring the electrical stimulation directly to the muscle, more particularly to the motor point of the diaphragm, rather than to the phrenic nerve. Since it can be implanted easily and simply, it minimizes the nerve damage that may occur during the operation and significantly improves the operation safety.

Advantageous Effects

[18] In accordance with the present invention, an electrical stimulation signal generated from the outside of a body is transferred into the human body by non-contact method and the transferred signal is finally transferred to the motor point of the diaphragm to stimulate diaphragmatic contraction. The diaphragm stimulator according to the present invention and the breath pacemaking device comprising the same avoid the trouble of finding the phrenic nerve from the nerve fascicle when implanting the stimulator in the neck or chest. Further, they can fundamentally prevent the risk of damaging other nerves during operation. Accordingly, the operation becomes safer and easier. In addition, the diaphragm stimulator and the breath pacemaking device comprising the same can be constructed simply, so that the patients with respiratory disorder can better benefit from the breath pacemaking devices. Brief Description of the Drawings

[19] Fig. 1 is a schematic view illustrating the conventional diaphragm stimulator implanted in the human body.

[20] Fig. 2 is a perspective view of the implantable diaphragm stimulator in accordance with the present invention.

[21] Fig. 3 is a side view of the diaphragm stimulator shown in Fig. 2.

[22] Fig. 4 is a plan view of the inside of the intracorporeal signal receiving unit of the diaphragm stimulator shown in Fig. 2.

[23] Fig. 5 is a perspective view of the external part of the breath pacemaking device of the present invention.

[24] Fig. 6 is a perspective view of the external charging apparatus comprised in the breath pacemaking device of the present invention.

[25] Fig. 7 is a schematic diagram illustrating the signal transfer in the breath pacemaking device of the present invention.

[26] Fig. 8 is a schematic view of the motor point of the diaphragm.

[27] Fig. 9 is a schematic view illustrating the operation procedure for implanting the diaphragm stimulator according to the present invention.

[28] Fig. 10 is a schematic view illustrating the diaphragm stimulator according to the present invention implanted in the human body. Mode for the Invention

[29] Hereinafter, preferred embodiments of the present invention are more fully illustrated referring to the accompanied drawings.

[30] Fig. 2 is a perspective view of an implantable diaphragm stimulator (100) according to the present invention. As illustrated in Fig. 2, the implantable diaphragm stimulator (100) is comprised an intracorporeal signal receiving unit (120) and a stimulation signal transferring unit, which are electrically connected. This system is implanted by operation in order to provide electrical stimulation to the motor point of the diaphragm. Description about the motor point of the diaphragm and the operation procedure will be given later.

[31] At one end of the diaphragm stimulator (100), the intracorporeal signal receiving unit (120) is positioned for wirelessly receiving an electrical signal from outside of a body. At the other end is the stimulation signal transferring unit which receives the electrical signal from the intracorporeal signal receiving unit (120) and finally transfers the electrical stimulation signal to the motor point of the diaphragm. The stimulation signal transferring unit comprises a wire (140) which provides an electrical path and contact point (162) located at the end of the wire (140) and has a direct contact to the motor point of the diaphragm. The contact point (162) is exposed on the surface of a fixation wing (160) which is made of a biocompatible material and functions as a case providing physical support.

[32] Fig. 3 is a side view of the diaphragm stimulator (100). The intracorporeal signal receiving unit (120) may be formed in a thin disk-shaped structure. It comprises a circuitry for demodulating the electrical stimulation signal transferred from outside and is connected to one end of the wire (140) for transferring the stimulation signal. At the other end of the wire (140), the fixation wing (160) is connected, which may also be formed in a thin disk-shaped structure. The contact point (162) protrudes on the surface of the fixation wing. Internally, the contact point (162) is electrically connected to the wire (140) and, externally, they are exposed in part for easier direct contact with the motor point of the diaphragm. Particularly, the fixation wing (160) helps the contact point (162) to be fixed at the motor point of the diaphragm.

[33] Fig. 4 illustrates the inside of the intracorporeal signal receiving unit (120). Inside a disk-shaped case (121), a coil (123) is positioned for receiving signal and a magnet (124) is at the center of the case. At one side of the coil is a circuitry (122) for demodulating the stimulation signal received from outside of a body. The shapes or positions of the case (121), circuitry (122), coil (123) and magnet (124) are exemplary.

[34] The coil (123) performs the function of antenna. For example, it may be a wound metal wire or a coil pattern formed on a PCB (printed circuitry board). The magnet (124) generates a magnetic attraction so that the intracorporeal signal receiving unit

(120) is fixed with the external device in a non-contact form. The shape of the case

(121) needs not be limited to a disk. A structure that ensures the sealing of the inside is sufficient. It is made of a biocompatible material, preferably one having elasticity so that it does not physically stimulate the inside of the body. In an embodiment of the present invention, polyether ether ketone is used for the case, which is a non-limiting example of such material. Further, a biocompatible material, for example, a silicone based polymer material, may be filled inside the case to protect the components inside the case and prevent the exposure thereof.

[35] The wire (140) that electrically connects the intracorporeal signal receiving unit

(120) with the stimulation signal transferring unit may have any length, as long as it can provide sufficient contact to the motor point of the diaphragm. But, it is preferable that the wire (140) is as thin as possible in order to minimize physical stimulation in the body. Also, preferably, the outer surface of the wire (140) is coated with a biocompatible material, such as silicone based polymer material, etc.

[36] Preferably, the fixation wing (160) of the stimulation signal transferring unit has a shape that can protect the joint of the end of the wire (140) with the contact point (162) and can ensure the fixation of the contact point (162). It can have a thin disk or elliptical structure. Also, preferably, the fixation wing (160) is made of a bio- compatible material. The number of the contact point (162) is at least one, preferably two one for an active electrode and the other for a reference electrode. The surface of the contact point (162) has a shape that can minimize physical stimulation in the body, preferably spherical or elliptical shape. Preferably, the contact point (162) is made of a metal or an alloy thereof that can directly transfer the electrical stimulation in the body without rejections. According to a specific embodiment of the present invention, platinum is used.

[37] The implantable diaphragm stimulator according to the present invention constitute a breath pacemaking device system along with the external part which generates an electrical stimulation signal from outside of a body and transfers the stimulation signal by non-contact method.

[38] As illustrated in Fig. 5, the external part (200) comprises a stimulation generating unit (220) which is equipped with a circuitry for generating the electrical stimulation to be transferred to a stimulation signal transmitting unit (260) which finally transmits the stimulation signal to the intracorporeal signal receiving unit. The stimulation generating unit (220) and the stimulation signal transmitting unit (260) may be connected by a wire (240).

[39] The stimulation generating unit (220) may comprise a controller for controlling the strength, duration and interval of the electrical stimulation, an electrical signal modulator, a voltage controller, etc., inside it. The external part may further comprise a display (222) for visually displaying the electrical stimulation and a stimulation signal control button (224). Further, the stimulation generating unit (220) may comprise a power supply such as removable built-in battery, external charging apparatus, etc. for supplying the power needed to generate the electrical stimulation signal. In Fig. 6, an external charging device for supplying the power to the chargeable battery built inside the stimulation generating unit (220) is illustrated as an example.

[40] Similarly to the intracorporeal signal receiving unit (120) illustrated in Fig. 4, the stimulation signal transmitting unit (260) may comprise a coil for transmitting signal. Further, it may comprise a magnet so that it can be fixed with the intracorporeal signal receiving unit by non-contact method, with the human skin between them.

[41] The implantable diaphragm stimulator (100) as an implanted part and the external part (200), which are wirelessly coupled with each other, constitute the breath pacemaking device according to the present invention. The two may be coupled by non-contact method. Alternatively, they may be spaced with a certain distance, provided that wireless electrical signal transfer is attained.

[42] Fig. 7 is a schematic diagram illustrating the signal transfer between the implantable diaphragm stimulator (or an implanted part) (100) and the external part (200).

[43] In spite of the absence of the physical direct contact of the implanted part and the external part, the two may be fixed with one another, with the human skin between them, due to the magnetic attraction of magnets (124, 264). Such magnetic non-contact fixation improves the reliability of signal transfer between the external part and the implanted part and ensures easier wearing of the external part by the patient. However, the distance or spacing between the implanted part and the external part will be no problem if the transmission and reception of the electrical signal is performed well. The signal transfer between the external part and the intracorporeal apparatus (I in Fig. 7) is performed by non-contact method, or wireless communication. In contrast, the electrical stimulation signal transfer from the intracorporeal apparatus to the motor point of the diaphragm (II) is carried out by direct transfer.

[44] Through a power supply such as built-in battery, the external part supplies a voltage required by the built-in circuitry. Depending on the respiration rate and strength set by the user, the controller generates a stimulation signal and the result is displayed on a monitor such as LCD. The generated signal is modulated and transmitted to the stimulation signal receiver of the implanted part through a coil-type antenna built in the signal transferrer. The signal received through the coil of the signal receiver implanted in the body is demodulated into an electrical signal and is transferred to the motor point of the diaphragm through the aforementioned contact point. The electrical stimulation which transferred to the diaphragm induces diaphragmatic contraction and helps the patient's respiration.

[45] The diaphragm stimulator and the breath pacemaking device comprising the same can be constructed more simply, the patients with respiratory disorder can overcome the difficulty of accessing the treatment using expensive devices.

[46] Fig. 8 is a schematic view of the motor point of the diaphragm. The diaphragm comprises a tendon (420) and a muscle (410). The motor points of the diaphragm (440) are located at the left side and right side of the tendon (420). Several phrenic nerves (430) project from the motor points.

[47] The inventors of the present invention confirmed that the motor points, which are

1-2 cm in size, actually exist at the left side and right side of the middle of the diaphragmatic tendon through an animal test. Further, they confirmed that the diaphragm contracts when an electrical stimulation is applied to the motor point after fixing the positions of the ground electrode and the active electrode of the implantable diaphragm stimulator according to the present invention.

[48] The operation of inducing diaphragmatic contraction by applying electrical stimulation to the motor point in accordance with the present invention is a breakthrough that can ensure operation safety and reduction in operation cost.

[49] As described earlier, the conventional operation method, in which the chest cavity is cut open to find the phrenic nerve from the nerve fascicle to which the electrodes are connected has the problems including insanitariness, risk of disconnection of devices, and so forth.

[50] However, as schematically illustrated in Fig. 9, the implantable diaphragm stimulator according to the present invention can be simply implanted by cutting open the abdomen (500) and using a laparoscope or other tools (510, 520). Also, the operation is very safe because the phrenic nerve is intact and the opening area can be minimized.

[51] Fig. 10 is a schematic view illustrating the diaphragm stimulator according to the present invention implanted in the human body. The fixation wing (160) of the stimulation signal transferring unit is located at the motor point (440) of the diaphragm (410) and the intracorporeal signal receiving unit (120) connected by the wire (140) is fixed with the stimulation signal transmitting unit (260) of the external part, with the skin between them. The stimulation generating unit (220) of the external device generates the optimum stimulation signal depending on the patient's status and safely transfers the signal to the motor point of the diaphragm in order to effectively overcome the respiratory trouble.

[52] As described, it should be evident that the present invention can be implemented through a variety of configurations in the aforementioned technical field without affecting, influencing or changing the spirit and scope of the present invention. Therefore, it is to be understood that the examples and applications illustrated herein are intended to be in the nature of description rather than of limitation. Furthermore, the meaning, scope and higher conceptual understandings of the present invention as well as modifications and variations that arise therefrom should be understood to be extensions to this invention.

Claims

[1] An implantable diaphragm stimulator comprising: a signal receiving unit which wirelessly receives an electrical stimulation signal from outside of a body and demodulates the received stimulation signal; and a stimulation signal transferring unit which directly transfers the stimulation signal demodulated by the signal receiving unit to a motor point of a diaphragm.

[2] The implantable diaphragm stimulator as set forth in claim 1, wherein the signal receiving unit comprises a coil for receiving the electrical stimulation signal from outside of a body, a circuitry for demodulating the received stimulation signal and a magnet for a non-contact fixation with an external device.

[3] The implantable diaphragm stimulator as set forth in claim 1, wherein the stimulation signal transferring unit comprises at least one contact point that directly contacts the motor point of the diaphragm and directly transfers the electrical stimulation signal to the motor point of the diaphragm.

[4] The implantable diaphragm stimulator as set forth in claim 3, wherein the stimulation signal transferring unit comprises two contact points, one for an active electrode and the other for a reference electrode.

[5] The implantable diaphragm stimulator as set forth in claim 4, wherein the stimulation signal transferring unit comprises a fixation wing for fixing the contact point in which the contact point are protruded on a surface of the fixation wing.

[6] The implantable diaphragm stimulator as set forth in claim 1, wherein the signal receiving unit and the stimulation signal transferring unit are connected by a wire coated with a biocompatible material.

[7] The implantable diaphragm stimulator as set forth in claim 1, wherein the signal receiving unit is protected by a biocompatible case and silicone is filled inside the case.

[8] A breath pacemaking device comprising: an implanted part which comprises an intracorporeal signal receiving unit that wirelessly receives an electrical stimulation signal from outside of a body and demodulates the received stimulation signal and a stimulation signal transferring unit that directly transfers the stimulation signal demodulated by the intracorporeal signal receiving unit to a motor point of a diaphragm; and an external part which comprises a circuitry that generates the electrical stimulation signal to be transferred to the implanted part, a controller that controls strength, duration and interval of the electrical stimulation signal and a display that visually displays the strength, the duration and the interval of the electrical stimulation signal. [9] The breath pacemaking device as set forth in claim 8, wherein the stimulation signal transferring unit comprises at least one contact point that directly contacts the motor point of the diaphragm and directly transfers the electrical stimulation signal to the motor point of the diaphragm. [10] The breath pacemaking device as set forth in claim 8, wherein the external part comprises a stimulation signal transmitting unit which transmits the electrical stimulation to the implanted part. [11] The breath pacemaking device as set forth in claim 10, wherein the stimulation signal transmitting unit comprises a coil for transmitting the electrical stimulation signal and a magnet for a non-contact fixation with the intracorporeal signal receiving unit.