Deep brain stimulation device having wireless power feeding by magnetic induction

Provided is a deep brain stimulation (DBS) device having power wirelessly fed by magnetic induction. A rotating magnetic field is formed using a rotating magnetic field disk installed inside a hat of a patient. The rotating magnetic field generates induced power using an induction coil plate fixed underneath a scalp of the patient to drive electrodes implanted into a brain of the patient so as to correct abnormal motor and sensory functions of the patient using power wirelessly fed from an external device into the electrodes. The DBS device includes: a hat module installed inside a hat of the patient to generate a rotating magnetic field; and an implantation module implanted through a skull under a scalp to contact a nervous system of the patient and combined with the rotating magnetic field of the hat module to stimulate the cerebral nerve using induced power generated by the magnetic induction.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a national phase application based upon priority International PCT Patent Application No. PCT/KR2008/002664 filed 14 May 2008, International Publication No. WO/2008/140243 A3 published 20 Nov. 2008, which is based upon priority Korean Patent Application No. 10-2007-0046408 filed 14 May 2007.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a deep brain stimulation (DBS) device having power wirelessly fed by a magnetic induction, and more particularly, to a DBS device which forms a rotating magnetic field by a rotating magnetic field disk installed inside a hat put on a patient and generates induced power by an induction coil plate fixed underneath a scalp of the patient so that the induced power is combined with the rotating magnetic field to drive electrodes implanted into a brain of the patient so as to correct abnormal motor and sensory functions of the patient using power wirelessly fed from an outside into a body of the patient.

2. Background Art

People are exposed to accidents or diseases that may result in them losing the ability to function or move. There are limits to curing such patients in medical science. Medical and biological engineering in which an engineering field is grafted into a medical field has been developed in order to overcome the above-described limits. Thus, many areas of a health management system have been changed.

For example, cardiac pacemakers and defibrillators have saved lives of hundreds of people and cured heart diseases. Also, surgeons implant deep brain stimulation (DBS) devices into brains of patients to control abnormal brain functions of the patients using techniques of cardiac pacemakers.

Abnormal physical actions or mental disorders derive from abnormal functions of brains such as a Parkinson's disease or an obsessive-compulsive disorder (OCD). The Parkinson's disease is a chronic degenerative disease whose main symptoms are shivering of hands and feet, slow actions, and hardening of muscles. In other words, the Parkinson's disease is a mental disease by which a person with an OCD avoids going out due to a fear of contaminations from things that the person contacts.

Neurosurgeons use DBS devices to cure health problems such as the Parkinson's disease, an OCD, and hypochondria. A curing method using a DBS device is an only surgical method for curing an OCD and is effective in curing the Parkinson's disease. This curing method requires a process of implanting an electrode, which inhibits or stimulates a predetermined part of a cerebral nerve, into a deep part of a brain in order to normalize a function of the brain of a patient.

Operations using DBS devices have been performed since Alim-Louis Benabid in the Grenoble University Hospital of France reported on 80 or more Parkinson's disease patients in 1993. Thus, about thirty thousand similar operations have been very successfully performed throughout the world. Such a DBS device applies current pulses to a cerebral nerve through electrodes, which are implanted into an accurate position of the cerebral nerve, in order to stop shivering, which is a main symptom of a disease, and relax stooped muscles.

DBS devices contribute to controls of extant diseases. However, when a DBS device uses an electric wire in a human body to supply power, transmit data, and make a program, a plurality of problems occur.

FIG. 1illustrates a conventional DBS device which is implanted into a human body. Referring toFIG. 1, the conventional DBS device includes an electrode needle146and a power supply unit160. The electrode needle146is implanted into a cerebral nerve to provide an electric stimulation to the cerebral nerve so as to restore an abnormal function of a brain. The power supply unit160is connected to the electrode needle146through an electric wire150to feed power to the electrode needle146.

The conventional DBS device having the above-described structure sews the power supply unit160having a power source such as a battery into abdomen or thorax to be turned on or off by remote control using a skin. Thus, the DBS device is clinically simply used. However, the DBS device provides hard inconvenience to a patient. Also, if the electric wire550installed underneath the skin of the patient short-circuits or power of the battery installed in the abdomen or thorax is consumed, a surgical operation is repeatedly performed to replace or repair a corresponding part.

BRIEF SUMMARY OF THE INVENTION

Disclosure of Invention Technical Problem

The present invention provides a deep brain stimulation (DBS) device which electrically stimulates a cerebral nerve of a patient using power, which is wirelessly fed from an outside into a body of the patient.

Advantageous Effects

A deep brain stimulation (DBS) device having power wirelessly fed by a magnetic induction according to the present invention normalizes an abnormal cerebral nervous system of a patient and strengthens weakened functions of the cerebral nervous system. Also, the DBS device does not include an additional power feeding device which is implanted into a body of the patient and thus does not require an additional operation for replacing a power source and an electric wire. The DBS device permanently operates due to an only one-time performance of an operation for implanting the DBS device. Thus, maintenance cost of the DBS device is considerably saved, pains of a patient causes by repeated operations are relieved.

A more detailed explanation of the invention is provided in the following detailed description and appended claims taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

The following is a detailed description and explanation of the preferred embodiments of the invention and best mode for practicing the invention.

Best Mode for Carrying out the Invention

According to an aspect of the present invention, there is provided a deep brain stimulation (DBS) device including: a hat module which is installed inside a hat put on a head of the patient to generate a rotating magnetic field; and an implantation module which is implanted through a skull under a scalp to contact a nervous system of the patient and combined with the rotating magnetic field of the hat module to stimulate the cerebral nerve using induced power generated by the magnetic induction.

Mode for the Invention

FIG. 2illustrates a DBS device having power wirelessly fed by a magnetic induction according to an embodiment of the present invention. Referring toFIG. 2, a DBS device10of the present embodiment includes an implantation module4and a hat module3. The implantation module4is implanted into a head of a patient. The hat module3is installed inside a hat2put on the head of the patient to generate a rotating magnetic field so as to wirelessly feed power which is to be used by the implantation module4.

The implantation module4includes a stimulation pin46and an induction coil plate41. The stimulation pin46is implanted through a skull under a scalp to contact a deep cerebral nerve so as to provide an electric stimulation to the deep cerebral nerve of the patient. The induction coil plate41generates induced power for driving the stimulation pin46.

Here, the induction coil plate41is combined into the skull under the scalp using screws, and the stimulation pin46is connected to a center of a lower surface of the induction coil plate41to be fixed into a position in which a nervous stimulation is to be provided.

The hat module3includes a rotating magnetic field disk33, a small-sized electric motor32, and a controller31. The rotating magnetic field disk33generates a rotating magnetic field toward the induction coil plate41of the implantation module4in order to generate power which is to be used to drive the implantation module4. The small sized electric motor32rotates the rotating magnetic field disk33, and the controller31controls the small-sized electric motor32.

The rotating magnetic field disk33of the hat module3and the induction coil plate41of the implantation module4constitute a wireless power feeding module to wirelessly feed power through a magnetic induction generated between the rotating magnetic field disk33and the induction coil plate41. Thus, the DBS device10self-feeds power for driving the stimulation pin46without installing an additional power source into the body of the patient.

FIG. 3is a perspective view of parts of the wireless power feeding module using an induction coil, shown inFIG. 2. Wireless power feeding between the implantation module4and the hat module3is shown inFIG. 3.

The wireless power feeding uses induced power. In other words, the wireless power feeding is a method of generating induced power by a relative motion between the rotating magnetic field disk33of the hat module3and the induction coil plate41of the implantation module4.

As shown inFIG. 3, a plurality of small-sized magnets34are attached on a surface of the rotating magnetic field disk33to be disposed at equal intervals along a circumference of the rotating magnetic field disk33. A minute induction coil42is formed of a metal line in a predetermined pattern on the induction coil plate41having a thin film shape so as to be disposed around a power modulator43which is positioned in the center of the induction coil plate41. If the rotating magnetic field disk33of the hat module3rotates based on an axis, magnetic force lines generated from the smallsized magnets34rotate. Thus, induced power is generated from the induction coil plate41which is fixed underneath the scalp. The induced power is transmitted to the power modulator43connected to the minute induction coil42to be used to drive the stimulation pin46which is to stimulate neurons in the brain.

Power necessary for stimulating a deep brain may be pulse waves which have a minimum frequency of 200 Hz, a pulse width between 60 μsec and 500 μsec, and a magnitude between 0V and ±10V.

Therefore, the power modulator43modulates direct current (DC) power, which is generated by the magnetic induction generated by the minute induction coil42, into pulse waves which have a magnitude between 0V and ±10V, a frequency of 200 Hz, and a pulse width between 60 μsec and 500 μsec. Next, the power modulator43feeds the pulse waves to the stimulation pin46.

The stimulation pin46is an only part which is buried into the brain to stimulate the deep brain. Also, the induction coil plate41, which is formed of a minute thin film and positioned between the scalp and the skull, is combined with a magnetic field which rotates to generate power required for performing functions of the stimulation pin46. Therefore, the induction coil plate41transforms kinetic energy into electric energy which is to be used by the implantation module4and feeds the electric energy to the implantation module so as to wirelessly feed power from the hat module3positioned outside the body of the patient to the implantation module4implanted into the body of the patient. Here, the kinetic energy is generated by the small-sized electric motor32of the hat module3using the rotating magnetic field disk33and the induction coil plate41which are opposite to each other so that an air gap is formed between the rotating magnetic field disk33and the induction coil plate41.

The stimulation pin46is implanted into a minute path of an activity cerebral cortex so that a lower end of the stimulation pin46contacts a deep cerebral nerve. A body of the stimulation pin46may be formed of a material which does not react to and reject fluid in a human body. In particular, the body of the stimulation pin46may be formed of a polymer or ceramic material which is physiologically well adapted to the human body.

A plurality of stimulation electrodes47are installed at the lower end of the stimulation pin46to transmit a voltage for stimulating the cerebral nerve. An insulating material is coated from upper surfaces of the stimulation electrodes47up to a tip area in order to prevent an electric leakage to the human body. Here, the plurality of stimulation electrodes47installed in the stimulation pin46are formed of insulation coated gold lines.

FIG. 4is a block diagram of the DBS device10ofFIG. 2.

A whole structure and operation of the DBS device10will now be described in detail with reference toFIG. 4.

As previously described, the DBS device100includes the hat module3which is installed inside the hat2put on the patient and the implantation module4which is implanted into the brain of the patient.

The hat module3includes the small-sized electric motor32, the rotating magnetic field disk33, a transmitter35, and the controller31. The controller31rotates the small-sized electric motor32at a constant speed and transmits a nerve stimulation command signal7to the implantation module4through the transmitter35.

A central portion of the rotating magnetic field disk33is connected to a shaft of the small-sized electric motor32so that the rotating magnetic field disk33rotates with driving of the small-sized electric motor32. Thus, the plurality of small-sized magnets34, which are attached on an upper surface of the rotating magnetic field disk33to form a concentric circle based on the axis, rotate so as to rotate a magnetic field6formed toward the implantation module4.

A power feeding unit (not shown) is installed to be connected to the controller31and the small-sized electric motor32so as to feed power to the whole circuit and the smallsized electric motor32of the hat module3.

The implantation module4implanted into the brain includes the stimulation pin46, the induction coil plate41, a receiver45, and the power modulator43. The simulation pin46includes the stimulation electrodes47, and the induction coil plate41wirelessly receives energy and transforms the energy into power. The receiver45receives a command signal from the transmitter35of the hat module3. The power modulator43modulates the power generated by the induction coil plate41into power which is to be used by the whole circuit and the stimulation pin46.

Here, the stimulation electrodes47transmit a stimulation signal8to the cerebral nerve to inhibit an abnormal motor or sensory function of the patient.

Accordingly, the rotations of the small-sized magnets34of the hat module3generate induced electricity in the minute conduction coil42of the induction coil plate41implanted underneath the scalp. Next, the power modulator43modulates the induced electricity into DC current having a predetermined voltage necessary for driving a system and feeds the DC current to the whole circuit and the stimulation electrodes47. In other words, power is not directly transmitted by wire but is generated by the minute induction coil42which is combined with the magnetic field which continuously varies, passing through a thickness of the skin. The generated induced power is modulated into the DC power to drive the implantation module4including the stimulation pin46. Here, as described above, the power fed to the stimulation pin46has a pulse waveform required for stimulating a deep brain stimulation.

Here, the hat module3includes a switch (not shown) which is connected to the controller31and turns on and/or off a cerebral nerve stimulation function of the implantation module4. Thus, the controller31drives the small-sized electric motor32and transmits a cerebral nerve stimulation command signal to the receiver45of the implantation module4through the transmitter35according to an operation of the switch. Next, the controller31operates the power modulator43according to the cerebra nerve stimulation command signal to feed pulse power to the stimulation electrodes47so as to simulate the cerebral nerve.

If the induced power is generated by an interaction between the rotating magnetic field disk33and the induction coil42generated by the driving of the small-sized electric motor32without installing the transmitter35and the receiver45, the power modulator43may immediately operate to feed the pulse power to the stimulation electrodes47.

A patient who is implanted with the DBS device10having the above-described structure is able to freely move with the hat2adjacent to the minute induction coil42implanted into a brain of the patient. If an abnormal symptom, such as hand shivering of a Parkinson's disease patient, occurs in a cerebral nerve of the patient, the patient or another person may operate the switch of the hat2to combine rotating magnetic force lines generated from the rotating magnetic field disk33of the hat module3with the induction coil42implanted underneath the scalp in order to generate induced power. Next, the stimulation pin46may be operated by the induced power so as to solve an abnormal function of a brain of the patient.

As described above, a DBS device having power wirelessly fed by a magnetic in duction according to the present invention wirelessly transmits power compared to a conventional DBS device which is sewed into abdomen or thorax to be turned on and/or off by remote controls through a skin. Thus, the DBS device does not require a surgical operation which is performed to replace a battery and other elements implanted into a body of a patient.

Industrial Applicability

A DBS device having power wirelessly fed by a magnetic induction according to the present invention normalizes functions of a patient having an abnormal cerebral nervous system and strengthens weakened functions of the cerebral nervous system. Also, the DBS device permanently operates through only a one-time operation.

Although embodiments of the invention have been shown and described, it is to be understood that various modifications, substitutions, and rearrangements of parts, components, and/or process (method) steps, as well as other uses of the DBS device, can be made by those skilled in the art without departing from the novel spirit and scope of this invention.