CN2734251Y - Impulse generating device of implantation type brain artificial pacemaker for treating Parkinson's disease - Google Patents

Abstract

An implantable brain pacemaker pulse generator for the treatment of Parkinson's disease. The electrical pulse sent is transmitted to the stimulation electrode implanted in the brain through a wire, and the Parkinson's disease is treated with continuous pulse electrical stimulation. The pulse generator is composed of highly integrated low-power single-chip microcomputer, battery, voltage regulator, radio frequency communication, reed switch, pulse generator and driver, etc. It simplifies the circuit design as much as possible, and uses software to realize various functions of the brain pacemaker. Improved system reliability. The pulse generator is controlled by an external magnet and a programmer for non-contact start/stop and adjustment of pulse parameters. The pulse generator achieves electrical stimulation with adjustable parameters such as stimulation intensity, frequency, and pulse width to the target area, which is conducive to finding the best stimulation contact point, so that it has the advantages of better curative effect and longer duration.

Description

A pulse generator for implantable brain pacemaker for treating Parkinson's disease

technical field

The utility model relates to an implantable brain pacemaker pulse generator for treating Parkinson's disease through chronic electrical stimulation of brain target tissue, which is a deep brain stimulation treatment instrument.

Background technique

Parkinson's disease is a degenerative disease of the central nervous system that occurs in middle age and above, and the main lesions are in the substantia nigra and striatum of the brain. Drug therapy is the most basic treatment method for Parkinson's disease, and traditional surgical treatment mainly uses the method of destroying the lesion. Brain pacemaker therapy achieves the therapeutic effect through chronic electrical stimulation, the effect is completely comparable to that of lesion surgery, and it is a reversible neuromodulation therapy that does not destroy brain tissue, plays a role in treating the cause, and delays Parkinson's disease itself Progression of the disease is currently the most ideal surgical treatment. An implanted brain pacemaker consists of electrodes in the brain, extension leads, and a pulse generator. The pulse generator is implanted subcutaneously near the clavicle in the chest through surgery, and the stimulating electrodes are inserted into specific nuclei in the brain through stereotaxic technology and microelectrode recording technology. The electrical pulse sent by the pulse generator is transmitted to the stimulating electrode through a wire implanted under the skin, through the head, neck, and shoulders, and acts on specific nuclei in the brain, and uses continuous pulse electrical stimulation to suppress the discharge of abnormal brain nuclei to achieve The effect of treating Parkinson's disease.

Chinese invention patent "multi-channel implantable neurostimulator" (application number 86103049), uses an external transmitter to send digitally encoded signals and energy through the skin to the implanted receiver/stimulator, and the stimulator decodes the bit stream, A charge or current waveform is sent to electrodes implanted in the auditory nerve or cochlea. The stimulator must be controlled by an external transmitter to work at the same time. The circuit structure and algorithm determine that the stimulator can only be used in the auditory nerve repair system, and it is not suitable for the brain pacemaker treatment of Parkinson's disease. The published Chinese invention patent (Application No. 01810456.8) "Implantable and Programmable Electrical Stimulator for Stimulating Organs and Tissues of Organisms" spreads biosensors all over the surface of the shell, and the respiratory and cardiovascular changes caused by diseases are detected The sensor records, according to a certain algorithm, the formation of current pulses on the wire electrodes. Based on the physiological signals of breathing and cardiovascular, the stimulator changes the functional activities of tissues and organs through electrical stimulation, and its system scheme, circuit structure and algorithm cannot be used for the brain pacemaker treatment of Parkinson's disease.

Contents of the invention

The purpose of the utility model is to provide a pulse generator for an implantable brain pacemaker for treating Parkinson's disease, which can provide electric pulse stimulation to the target area according to the pulse parameters set by an external programmer.

The utility model is characterized in that it contains:

1. Single-chip microcomputer, using chip MSP430F155;

2. The power converter adopts the chip AS1117, its input terminal is connected to the battery, and its output terminal is connected to the power terminal of the above-mentioned single-chip microcomputer;

3. Pulse generation and drive circuit, including:

The voltage source adopts the micro-power switch-type voltage conversion chip MAX630. The low-potential detection terminal LB1 of the power supply is connected to the power supply through a voltage dividing resistor, while the output terminal Vs is connected to the positive terminal of the stimulating electrode, and the feedback terminal Vfb is connected to a set of parallel sampling resistors. It is connected to the corresponding IO port of the above-mentioned single-chip microcomputer, and is connected to Vs through a fixed resistor at the same time.

current source, containing:

The positive input terminal of the operational amplifier is connected to an output terminal of the above-mentioned single-chip microcomputer through a resistor, and the negative input terminal is respectively connected to the corresponding IO ports of the above-mentioned single-chip microcomputer through a group of parallel resistors.

The first NPN triode, its base is connected with the output terminal of the above-mentioned operational amplifier, and its emitter is grounded after a resistor connected in series and a normally closed end of a following reed switch (i.e. magnetically controlled double-throw switch); The collector is connected to the base of a PNP transistor through a resistor, and the collector of the PNP transistor is connected to an IO port of the above-mentioned single-chip microcomputer.

The base of the second NPN transistor is connected to the collector of the first NPN transistor through a forward diode, and at the same time connected to the output terminal Vs of the above-mentioned MAX630 chip through a capacitor; The positive terminal of the stimulating electrode is connected to the back of the voltage tube; the emitter is connected to the negative terminal of the stimulating electrode through a capacitor through a voltage regulator tube whose positive electrode is grounded.

4. Signal receiving/resetting circuit, including:

The third NPN triode, its collector is connected to a serial input port of the above-mentioned single-chip microcomputer after being acted on by a pull-up resistor; its base is connected to the end point of the resistance voltage dividing branch after the voltage regulator tube connected to the ground is reversed, and then After passing through a capacitor and a coil inductance for sensing control signals, it is grounded.

The reed switch is a magnetically controlled double-throw switch. Its normally closed end is grounded through the fixed end, and the normally open end is connected to the RST end of the above-mentioned single-chip microcomputer through the current limiting resistor after the action of the pull-up resistor, that is, the reset end.

The single-chip microcomputer has a communication interface for a radio frequency communication circuit wirelessly connected with an external programmer.

In the MAX630 chip, its Cx terminal and Lx terminal are respectively connected to a capacitor and an inductance for adjusting the internal switching frequency.

The single-chip microcomputer is externally connected with two crystal oscillators of 32.768KHz and 8MHz for adjusting the working frequency.

The utility model work process is as follows:

Just touch the chest position with a magnet, the pulse generator starts, the single-chip microcomputer reads the pulse parameters (including frequency, pulse width, amplitude, etc.) On the electrodes, thereby discharging in the targeted area, relieving the patient's symptoms. Once the magnet touches again, the pulse generator stops outputting pulses. The utility model is easy to use, and realizes electric stimulation with adjustable parameters such as stimulation intensity, frequency, and pulse width on the target area, so that the best stimulation contact point can be found, and the utility model has the advantages of better curative effect and longer duration.

Description of drawings

Fig. 1 is a block diagram of the principle structure of the utility model.

Fig. 2 is the schematic circuit diagram of the utility model.

Detailed ways

The technical solution of the utility model is as follows:

The pulse generator provided by the utility model is composed of single-chip microcomputer, battery, power conversion, radio frequency communication, reed switch, pulse generation and driving circuits. The pulse generator uses a highly integrated low-power single-chip microcomputer, with 5 power-saving modes, integrated program FLASH, data RAM, data FLASH, timer, analog-to-digital converter AD, digital-to-analog converter DA, comparator, serial Communication ports, etc., use software to implement various functions of the pacemaker as much as possible, so as to simplify circuit design and improve system reliability. The reed switch and the radio frequency communication circuit are the interfaces for the pulse generator to accept external control. The patient or doctor can start or stop the pulse generator with an external magnet, and can adjust the parameters of the stimulation pulse with the programmer. The pulse generation and driving circuit of the single-chip microcomputer outputs electric pulses through the synergistic effect of the voltage source and the current source, and acts on the target brain tissue through electrode discharge.

Describe an embodiment of the present utility model below in conjunction with accompanying drawing.

Accompanying drawing 1 is the circuit structure diagram of the present utility model. With high integration and low power consumption single-chip microcomputer 1 as the core, powered by lithium battery 2, the voltage required by the system is obtained through power conversion 3, and the crystal oscillator circuit 4 provides the clock, which constitutes a single-chip microcomputer system. The reed switch 6 is a magnetic control switch, which cooperates with the reset circuit 5, and the pulse generator can be switched between the working state and the stopping state by an external magnet. The single chip microcomputer 1 receives the pulse parameter data sent by the external programmer through the radio frequency communication circuit 8 . According to the set parameters, the single-chip microcomputer controls the pulse generation and the drive circuit 7 to output electric pulses to the electrodes, so as to electrically stimulate the target area of the brain tissue. (the design of external magnet and programmer does not belong to the involved scope of the present utility model)

Accompanying drawing 2 is the circuit principle diagram of the present utility model. The pulse generator includes a power conversion unit, a control unit, a voltage source, a current source and a signal receiving/resetting circuit. The voltage source and the current source work together under the control of the single-chip microcomputer to realize the generation and driving functions of electric pulses.

The power conversion unit is composed of a high-performance lithium battery and a voltage regulator chip AS1117, and the output voltage of the battery is regulated by the AS1117 to supply power to each chip.

The control unit takes MSP430F155 as the core, controls the output of the voltage source and current source through the IO port, and adjusts the parameters of the stimulation pulse applied to the electrodes. The MCU is externally connected with two crystal oscillators of 32.768kHz and 8MHz to adjust the working frequency in different working states and save power consumption.

The voltage source consists of a micro-power switch type voltage conversion chip MAX630, and discrete components such as inductors, resistors, and capacitors. The MAX630 is directly powered by the battery, and its internal switching frequency is determined by the inductor L3 and the capacitor C22. The output terminal of the MAX630 is connected to the feedback terminal after passing through a voltage dividing resistor network. The sampling resistors R33, R34, R35, and R36 are connected to the IO port of the microcontroller. By changing the number of grounded sampling resistors, the output voltage of the MAX630 and the limit voltage amplitude of the discharge between implanted electrodes can be adjusted. When the pulse generator is working, the single-chip microcomputer periodically changes the output voltage of MAX630 under program control, which can stimulate the pulse width and frequency adjustment of the electric pulse.

The current source is composed of operational amplifier AR2, transistor Q8, resistors and voltage regulator tubes. The implanted negative electrode is connected to the collector of the transistor Q8 through the capacitor C21, the base of the transistor Q8 is connected to the output terminal of the operational amplifier, and the emitter is grounded. The positive terminal of the operational amplifier AR2 is connected to an output terminal of the single-chip microcomputer through a resistor, and the negative terminal is connected to the six output terminals of the single-chip microcomputer in parallel through six resistors R46, R48, R49, R50, R51, R52, and R53. Set the level of the IO port through the single-chip microcomputer, that is, change the number of grounding resistors at the negative end of the op amp, and then the magnitude of the current passing through the triode and the voltage divided by the resistor R60 can be changed, thereby adjusting the discharge voltage between the two implanted electrodes .

The signal receiving/resetting circuit is composed of coil inductance L4, reed switch (magnetically controlled double-throw switch) S2, triode Q7 and so on. The coil inductance L4 is connected to the base of the triode Q7 through the coupling capacitor C29. When the coil inductance L4 senses the signal from the external programmer, the collector of the triode will generate a corresponding voltage signal. Line input port, so as to realize functions such as triggering interrupt and receiving data. The normally open end of the magnetically controlled double throw switch S2 is connected to the low level reset end of the microcontroller. When there is a magnet effect, the normally open end is grounded, and the single-chip microcomputer is reset. The single-chip microcomputer records the number of resets in the data FLASH, the odd-numbered reset single-chip microcomputer works normally, and outputs electric pulses; after the even-numbered resets, the single-chip microcomputer enters a stop state and does not output electric pulses, that is, the non-contact start/stop control of the magnet to the pulse generator is realized.

Claims (4)

1. treat the pulse generator that Parkinsonian implanted brain pacemaker is used for one kind, it is characterized in that it contains:

(1) single-chip microcomputer adopts chip MSP430F155;

(2) supply convertor adopts chip AS1117, its input termination battery, and outfan connects the power end of above-mentioned single-chip microcomputer;

(3) pulse generation and drive circuit, contain:

Voltage source, adopt little power consumption switching mode voltage transformation chip MAX630, its power supply electronegative potential test side LB1 connects power supply through divider resistance, and outfan Vs connects the stimulating electrode anode, feedback end Vfb then links to each other with the corresponding I port of above-mentioned single-chip microcomputer behind the sample resistance of one group of parallel connection, links to each other with Vs through a fixed resistance simultaneously;

Current source, contain:

Operational amplifier, its positive input terminal links to each other with an outfan of above-mentioned single-chip microcomputer through resistance, and negative input end links to each other with the corresponding I port of above-mentioned single-chip microcomputer respectively after one group of parallel resistor;

First NPN audion, its base stage links to each other with the outfan of above-mentioned operational amplifier, and its emitter-base bandgap grading is ground connection behind the normal-closed end of a mutual placed in-line resistance and a following reed switch (being the magnetic control commutator); Its colelctor electrode links to each other with a PNP transistor base through resistance, and IO port of this PNP transistor collector and above-mentioned single-chip microcomputer links to each other;

Second NPN audion, its base stage through a forward diode with when above-mentioned first NPN transistor collector links to each other, link to each other with the outfan Vs of above-mentioned MAX630 chip through an electric capacity again; Its colelctor electrode connects the anode of stimulating electrode behind the stabilivolt of plus earth; Its emitter-base bandgap grading links to each other with the negative terminal of stimulating electrode through an electric capacity behind the stabilivolt of plus earth again.

(4) signal reception/reset circuit, contain:

The 3rd NPN audion, its colelctor electrode link to each other with a serial input port of above-mentioned single-chip microcomputer after the pull-up resistor effect; Its base stage at the stabilivolt of reversal connection over the ground with after the terminal point of electric resistance partial pressure branch road links to each other, ground connection after the coil inductance that an electric capacity, induction control signal are used again;

Reed switch is the magnetic control commutator, and its normal-closed end is through stiff end ground connection, and Chang Kaiduan connects the RST end of above-mentioned single-chip microcomputer, i.e. reset terminal again through current-limiting resistance after the pull-up resistor effect.

2. a kind of pulse generator that Parkinsonian implanted brain pacemaker is used for the treatment of according to claim 1, it is characterized in that: described single-chip microcomputer has a communication interface of using with the radio-frequency communication circuit of external programmer wireless connections.

3. a kind of pulse generator that Parkinsonian implanted brain pacemaker is used for the treatment of according to claim 1, it is characterized in that: described MAX630 chip, its Cx end, Lx end are connecting an electric capacity and an inductance that is used to adjust the internal switch frequency over the ground respectively.

4. a kind of pulse generator that Parkinsonian implanted brain pacemaker is used for the treatment of according to claim 1 is characterized in that: described single-chip microcomputer is external adjusts 32.768KHz that operating frequency uses and two crystal oscillators of 8MHz.

Images