FR2478996A1 - Body movement generator for heart pacemaker activation - uses breathing motion to operate electromagnetic or piezoelectric electric generator to replace batteries - Google Patents

Abstract

The electric generator is intended to replace batteries in electrically operated implanted surgical prostheses, such as heart 'pacemakers'. The generator uses regular muscular movement, e.g. breathing, to provide mechanical energy which is converted to electrical energy by electromagnetic or piezo-electric action. An operating arm is attached to the body at one end and, after passing through a flexible sealing cover, couples to an iron plate through a ball joint and a linkage. The iron plate closes a magnetic circuit comprising two permanent magnets and a ferromagnetic core surrounded by a coil. As the lever moves it varies the air gaps in the magnetic circuit, so producing the flux variation required to generate an e.m.f. in the coil. The e.m.f. is rectified and regulated by an electronic circuit responding to the breathing rate.

Description

The present invention relates to an electric current generator for implanted prosthesis, intended to replace the electric batteries commonly used in this field (pacemakers for example) and also making it possible to take into account certain natural rhythms for the optimal functioning of said prostheses.

Despite the progress made \ in the field of batteries, it is necessary to
v re to renew them from time to time9 which leads to surgical procedures that the invention proposes to eliminate by supplying electrical current for life.

In addition, in the case of pacemakers, the rhythm provided by the existing devices is constant and does not adapt to the case where the subject is called upon to make an effort.

 The generator proposed by the invention uses as a source of energy the natural movements of the body, for example the respiratory movements.

Mechanical energy is transformed into electrical energy by any horned principle: electromagnetic induction, piezoelectricity etc ...

Since movements such as the respiratory movements have a certain rhythm, this rhythm can be used to control others, such as that of the heartbeat; this automatically accelerates the heart if the subject begins to breathe more quickly during an effort.

This regulation is done by means of an electronic logic using part of the device.

The generator can, depending on the case, be contained in a case separate from use, or in the same case. All movements are ensured without friction, d? Nc without wear or seizing, by deformation of flexible parts.

 -t Figure 1 shows in section an electromagnetic induction generator, in a separate case.

Figure 2, a piezoelectric generator, in a separate case.

Figure 3, the electrical diagram of the generator.

 Figure 4, a possible diagram of the regulation logic.

 According to a first variant, and as shown in FIG. 1, the device operates by electromagnetic induction in a coil 1, mounted in a ferro-magnetic yoke 2 provided with a permanent magnet 3, and closed by a frame 4. C ' is the opening of the air gap 5 between yoke 2 and armature 4 which, by variation of reluctance, causes a variation of magnetic flux producing the current in the coil 1.

The air gap opening is produced as follows:
The body of the apparatus 6 and a lever 7 movable relative to one çgrAce to a ball joint 8 and a flexible wall 9 are joined respectively to two parts of the body in movement relative to each other, such that rib and vertebra, or remove and diaphragm, etc.

 The lever 7 can oscillate in any sebs around the ball joint 8. Its end is equipped with grooves and threads allowing the attachment of different tips adapted to each particular case.

a plate 10, itself connected to four wires 11, the end of which is attached to the central point of the frame 4.

This is guided by a flexible blade hinge 12.

If no force is exerted on the lever 7, the armature # is in contact with the magnet 3, the air gap 5 is zero, the wires 11 are returned, the lever? is in the extension of the axis of the body
It's your average or resting position.

Whatever the displacement given to the lever 7 around this position, at least one of the wires It pulls on the armature 4 and causes the opening of the air gap 5. The attraction of the magnet 3 recognizes it jue ceases the ac tior. on the e
According to a second variant, shown in FIG. 2, the generator operates by piezoelectricity.

The general shape is the same as in the first variant, but the armature, the coil and the magnet are replaced by a lever 13 pressing with a spring 14 on a piezoelectric crystal 15. Raising or lowering the lever 13 on crystal 15 there causes the appearance of electric charges.

 Whatever the principle chosen, since the movements are always alternating, the generator also produces alternating electric currents. The electrical diagram of FIG. 3 shows that a diode rectifier 16 is used to produce a rectified current always charging in the same direction a high capacity 7 at the terminals of which e -; - collected electrical energy, possibly regulated by a Zener diode or a more elaborate regulator 18.

If the rhythm of the mechanical energy source is to be used, a diode 19 supplies pulses at this rhythm. Optionally, a second one can be used to obtain reverse pulses.
FIG. 4 represents a possible logic diagram for slaving, for example, the heart rate to the respiratory rate.

 A clock 21 drives a pulse multiplier22 with two outputs.

 The fastest output attacks a shift register 23, one-way direction, at a speed such that the travel time of all the outputs corresponds to the maximum time that can exist between two pulses to the heart.

The first outputs 24 are traversed in a time corresponding to the minimum time between two cardiac pulses.

The penultimate outputs 25 and the last 26 are traversed in a time equal to the difference between the minimum and maximum times.

The outputs 25 are connected to a door input "and" 29.

 The current pulses supplied to each respiratory cycle by the diode 19 cause a positive voltage to progress from right to left on the outputs 28 of the shift register 27.

The pulses supplied by the slowest output of the reduction gear 22 cause a negative voltage to progress from left to right on these same outputs.

If the breathing is slower than the rate of the reduction gear 22, all the exits 28 will be negative, and will block the doors 29, the exits of which attack a door "or" 30.

 The shift register 23 will be traversed in full before the impu's- ~ r reaches the output 26, sending a pulse towards the heart in the maximum time.

 If the breathing is faster than the rhythm provided by the reduction gear 22, a positive tension appears on the outputs 28, and an equ which is established between the positive and negative outputs of the register 271 provo ~ uar ~ the opening of doors 29, all the more to the left as the respiratory rate is faster.

 Fewer outputs 25 are traversed before the first open door 29 appears, and less time has passed between two isions sent to the heart.

 Each pulse to the heart applied to the input 31 of the shift register 23 resets it to zero.

 Exploration speeds are not necessarily linear, but can follow any other law, for example logarithmic, to take into account physiological needs.

The logic described above can be independent of the source of electricity, and can possibly be used with a conventional stimulator to r ~ the, by taking control signals in electrical form at the level of a nerve or a muscle. respiratory.

Claims (7)

BEVENDICATIONS  1. Generator intended to provide lifelong electrical energy to implanted prostheses6, characterized in that it uses the mechanical energy provided by the natural movements of the body, and possibly takes into account the rhythm of these movements to regulate the functioning of prostheses.  2. Generator according to claim 1, characterized in that it comprises a body 6 and a lever 7 respectively connected to two parts of the body in relative movement with respect to each other. 3. Generator according to claim 2, characterized in that the movements of the lever 7 around the ball joint 8 are transmitted inside the body 6 through a flexible wall 9, and always causes traction on the movable element ( 4 or 13), regardless of the movement of the lever around its rest position. 4. Generator according to claim 3, characterized in that all the movements are made by elastic deformation, without wear or possibility of seizing. 5. Generator according to claim 4, characterized in that it transforms mechanical energy into electrical energy by electromagnetic induction, piezoelectricity.  6. Generator according to claim 5, characterized in that the alternating current produced is rectified by diodes 16 and charges a high capacity capacitor 17 connected to the use, possibly through a regulator 18.  7. Generator according to claim 6, characterized in that the rhythm of the mechanical power source can be used, by means of logic (19 to 31), to regulate the operation of the user device. Logic characterized by the fact that it can be used with electrical, electromagnetic, piezoelectric or battery sources of energy, for regulating prostheses, by taking control signals in electrical form from a nerve or a muscular.