JPH07246243A - Precutaneous charging device for apparatus to be inplanted into living body - Google Patents

Abstract

PURPOSE:To provide a percutaneous charging device for an apparatus to be inplanted into a living body capable of exactly fetching the information on monitor and control of charging out of a battery embedded into the body without being disturbed by an AC electromagnetic field at the time of charging to the battery. CONSTITUTION:Percutaneous charging means 10, 20 intermittently generate AC electromagnetic fields for charging the battery 53. The information on the monitor of the charging is transmitted and received between charging condition monitoring means 54, 56 and charging control means 34, 35 in the time band where this AC electromagnetic field is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a percutaneous charging device for externally charging an internal battery for a living body implanting device such as a cardiac pacemaker.

A primary battery having a large amount of energy per volume is used as a device for supplying electric power to a control circuit of a living body implanting device such as a cardiac pacemaker.
However, since the primary battery cannot be charged, when the battery reaches the end of its life, it is necessary to re-implant a device filled with a new battery, which imposes a heavy mental and physical burden on the patient. Therefore, introduction of a rechargeable secondary battery is desired.

However, in order to percutaneously charge a living body implanting device having a secondary battery from the outside of the body, it is necessary to determine whether or not to continue the charging operation based on the charging status of the secondary battery. It is necessary to send the information of outside of the body.

[0004]

2. Description of the Related Art Conventionally, in order to perform such charge control, an inverter circuit continuously generates an alternating electromagnetic field from the outside of the body to transmit power to the inside of the body, and from the inside of the body, charge a secondary battery. The monitoring information and the like are constantly transmitted to the external device by telemetry.

Then, an AC electromagnetic field for charging is generated from the outside of the body to transmit power to the inside of the body based on the monitoring information by telemetry such as the voltage of the secondary battery, and the charging operation is executed.

[0006]

In the conventional device as described above, the transmission of the alternating electromagnetic field from the outside of the body for charging and the transmission of the telemetry monitoring information from the inside of the body are simultaneously performed.

However, since the strength of the electromagnetic field for charging is extremely high during the power transmission operation, the telemetry electromagnetic field at the time of transferring the monitoring information of the secondary battery and the like to the outside of the body by telemetry is Received strong interference from the world.

As a result, there is an error in the transcutaneous transfer information by telemetry, it is impossible to control the charging of the secondary battery correctly, and the battery itself and other electronic circuit parts are destroyed due to overcharge of the secondary battery. There was a risk of tightening.

Therefore, the present invention provides a transcutaneous charge for a living body implanting device which can accurately take out charge monitoring control information from a battery embedded in the body without being disturbed by an AC electromagnetic field when charging the battery. The purpose is to provide a device.

[0010]

In order to achieve the above-mentioned object, a transdermal charging apparatus for a living body implanting device of the present invention is provided in a living body for supplying electric energy to the device implanted in the living body. A battery 53 to be embedded and a transdermal charging means 1 for transcutaneously transmitting power to the battery 53 by externally generating an AC electromagnetic field for charging the battery 53 in the living body.
0 and 20, charging status monitoring means 54 and 56 for monitoring the charging status of the battery 53 in the living body and transmitting the charging monitoring information transcutaneously outside the body, and the charging status monitoring means 54 and Transcutaneous body implanting device having charging control means 34 and 35 for receiving charging monitoring information sent from 56 outside the body and controlling the operation of the transdermal charging means 10 and 20 according to the contents of the signal. In the charging device, the transcutaneous charging means 10, 20 intermittently generate an AC electromagnetic field for charging the battery 53, and the charging status monitoring means 54, 54 during a time period when the AC electromagnetic field is not generated. 56
And charging control information is transmitted and received between the charging control means 34 and 35.

The charging control means 34, 35 provide the transcutaneous charging means 10, 20 when the electromotive voltage of the battery 53 does not reach a predetermined voltage as a result of monitoring by the charging status monitoring means 54, 56. AC electromagnetic field is generated intermittently,
When the electromotive voltage of the battery 53 reaches a predetermined voltage, the transcutaneous charging means 10 and 20 may stop the generation of the AC electromagnetic field.

Further, if the electromotive voltage of the battery 53 does not reach the predetermined voltage as a result of the monitoring by the charge status monitoring means 54, 56, the charge control means 34, 35 determine the charging current value and the predetermined value. The strength of the AC electromagnetic field may be controlled so that the charging current value becomes the above-mentioned predetermined value according to the magnitude of the difference.

Further, the charging status monitoring means 5 is further provided.
Alarming means may be provided for issuing an alarm when the charging current for the battery 53 does not reach a predetermined value as a result of monitoring by 4, 56.

[0014]

[Function] The transcutaneous charging means intermittently generates an AC electromagnetic field for charging the battery inside the body outside the body, and the charging status monitoring means and the charging control are performed during the time when the AC electromagnetic field for charging is not generated. The charging monitoring information is transmitted to and received from the means. Therefore, the transmission / reception of the charging monitoring information is not interfered with by the charging AC electromagnetic field.

[0015]

Embodiments will be described with reference to the drawings. Figure 1
1 is an overall configuration diagram of a percutaneous charging device for a living body implanting device.

Reference numeral 1 is a primary battery as a power source for a charger placed outside the body for percutaneously charging a living body implanting device (for example, a cardiac pacemaker). In order to make the strength of the alternating-current electromagnetic field for transcutaneous charging according to the voltage of the secondary battery 53 used in the living body implantation device, etc.
It is a transformer circuit for transforming (boosting) the voltage of the primary battery 1 outside the body, and includes an inductance 11, a switching transistor 12, a diode 13, a smoothing capacitor 14, and the like.

In order to obtain a desired DC voltage by stepping up or stepping down in the transformer circuit 10, the pulse width of the control pulse applied to the gate for making the switching transistor 12 conductive may be adjusted.

Reference numeral 20 is an inverter circuit for generating an AC electromagnetic field for percutaneous charging, which is basically constructed by combining four switching transistors 21 to 24 in series and parallel in a bridge shape.

In the inverter circuit 20, the DC voltage supplied from the transformer circuit 10 is supplied to the switching transistors 21 to 24 in pairs (21 and 24 and 22 and 2).
3) By combining and controlling so as to conduct at different times, an AC voltage is generated between A and B shown in the figure.

In order to change the amplitude of the AC voltage or to stop the generation, two sets of switching transistors 21 and 2 are used.
This can be implemented by changing the time width of the control pulse applied to the gates 4 and 22 and 23 or by stopping the applied control pulse. Reference numeral 25 is a smoothing capacitor.

Reference numeral 31 is a power transmission coil for transmitting power to a device implanted in the living body based on the AC voltage generated by the inverter circuit 20, and the coil specifies the radiation directivity of the electromagnetic field. It is braided on a ferrite core or the like in order to increase the strength and strength.

Reference numeral 100 denotes a living tissue such as muscle or fat interposed between the skin surface of the living body and a device implanted in the living body (hereinafter referred to as "living body skin 100").

Reference numeral 51 denotes a case of a living body implanting device (for example, a cardiac pacemaker), which is made of a metal such as titanium or a metal alloy, the surface of which is covered with a polymer resin or the like so as not to cause inflammation in the living body. To be done.

Reference numeral 52 denotes a power receiving coil mounted in the implanting device case 51, and an AC electromagnetic field for charging is transmitted from the power transmitting coil 31 outside the body via the skin 100 of the living body and the implanting device case 51. Receive power.

Reference numeral 60 denotes a power receiving rectifier circuit, which is composed of four diodes 61 to 64 combined in a bridge shape and a smoothing capacitor 65, and full-wave rectifies the AC voltage received by the power receiving coil 52 to ripple. To remove.

Reference numeral 53 is a rechargeable secondary battery that supplies electric energy for operating and controlling the implanting device, and is charged by the DC output of the power receiving rectifier circuit 60.
As a charging method, either constant voltage charging or constant current charging may be adopted.

The reference numeral 54 indicates when the secondary battery 53 is charged.
A current monitoring resistor having a known resistance value for monitoring the charging current. Since the internal impedance of the secondary battery 53 generally changes depending on the charging rate, in order to perform constant current charging on the secondary battery 53, it is necessary to constantly and appropriately change the strength of the AC electromagnetic field for charging. . The charging current value at this time can be converted from the potential difference generated across the current monitoring resistor 54.

Reference numeral 55 denotes a load including a control circuit of the implanting device, and the power for operating this load is supplied from the secondary battery 53. 56 measures the voltage difference of the secondary battery 53 and the potential difference generated across the current monitoring resistor 54 having a known resistance value as the charging current at the time of charging, and the voltage of the secondary battery 53 is determined based on these values. The charge monitoring control circuit is for determining whether or not a predetermined value has been reached and generating a control signal or the like for further continuing or stopping the charging operation.

Reference numeral 57 is a telemetry transmission circuit that modulates and transmits a carrier signal in order to transmit the output information from the charge monitoring control circuit 56 to the charger outside the body by telemetry. Reference numeral 58 denotes a transmitting antenna coil for transmitting the charging monitoring control information for telemetry from the implanted device to the receiving antenna coil 32 outside the body.

The transmission signal from the charge monitoring control circuit 56 is
The signal is transmitted from the transmitting antenna coil 58 to the outside of the body through the implanting device case 51 and the skin 100 of the living body, and is received by the telemetry signal receiving antenna coil outside the body. 33
Is a telemetry receiving circuit for demodulating the received telemetry signal and converting it into charging monitoring control information.

Reference numeral 34 denotes an inverter control circuit for controlling the operation of the inverter circuit 20. When receiving, for example, a telemetry signal indicating that charging is completed and charging should be stopped, the inverter control circuit 34 controls the operation of the inverter circuit 20. In order to stop the operation of the 20 switching transistors 21 to 24, the control pulse applied to the gate is output so as to be in a non-conducting state.

Reference numeral 35 denotes a charge control circuit which, as a charge monitoring control information, receives a gate for increasing the conduction period of the switching transistor 12 of the transformer circuit 10 when receiving a telemetry signal indicating that the charge current should be further increased. Control the pulse applied to the.

Reference numeral 36 is a display / alarm / operation circuit for monitoring the charge monitoring information of the secondary battery 53 of the implantable device with the external chargers 10 and 20, and for performing various necessary operations.

The transcutaneous charging device for a living body implanting device of the present invention is constructed as described above, and an AC electromagnetic field for charging is generated by the inverter circuit 20. This AC electromagnetic field is generated by the inverter circuit 20. Thus, the generation is controlled intermittently in a so-called burst manner with a fixed period as a unit.

FIG. 2 shows an example of the AC voltage generated in the inverter circuit 20. During the period of T ₀ (for example, 1 second), an AC voltage of, for example, 20 KHz is continuously generated in a burst and the next T ₁ is generated. The generation of the AC voltage is stopped for a period of (for example, 0.3 seconds), and T ₀ and T ₁ thereof are alternately repeated.

Such an AC voltage is applied to the power transmission coil 31 outside the body, and is received by the power receiving coil 52 inside the body via the skin 100 of the living body and the implanting device case 51, and is generated by the AC electromagnetic field received. The AC voltage is converted into DC by the power receiving rectifier circuit 60 built into the implanting device, and the secondary battery 53 is charged during the period of T ₀ .

As for the charging current value for the secondary battery 53, the potential difference between both ends of the current monitoring resistor 54 is measured during the period T ₀ , and the result is temporarily held in a register or the like not shown. Further, the voltage of the secondary battery 53 can be easily measured by measuring the terminal voltage of the secondary battery 53.

The charge monitoring control circuit 56 monitors the state of charge of the secondary battery 53. The transmission of these monitoring information to the extracorporeal device is performed during the period of T ₁ when the generation of the strong AC electromagnetic field is stopped for charging.

Further, the charging monitoring control circuit 56 is provided with a control signal for stopping the charging operation from the device outside the body when the secondary battery 53 is fully charged and the charging is completed. It includes a circuit to generate.

In this device, the strong AC electromagnetic field for charging is generated only for the period of T ₀ , and the charging monitoring control information is sent during the period of T ₁ when the generation of the AC electromagnetic field is stopped. It controls to send telemetry from the implanted device side to the outside of the body.

Therefore, the strong AC electromagnetic field for charging interferes with the telemetry signal having a small signal level to cause an error in the telemetry signal, or adversely affect the operation of the transmission / reception circuit of the telemetry signal and the charge control signal generation circuit. It is prevented, and a safe charging operation is performed as a result.

In FIG. 3, in the inverter circuit 20, T
An example of the charging AC voltage generation control circuit provided in the inverter control circuit 34 in order to continuously generate the AC voltage for the period of ₀ and then stop the generation of the AC voltage for the period of T ₁ is shown.

Here, the charging finger whose charging control information is "1"
When the indication is designated, the first differentiation circuit 71 causes T₀of
Output becomes "1" only for a period T₀Start the timer 72
It T ₀The timer 72 has been₀Period of
It outputs "1" and then becomes "0".

The output of the T ₀ timer 72 includes a first inverted logic gate 73 via a second differentiating circuit 74, the output only during the period of T ₁ is inputted to the T ₁ timer 75 becomes "1".
As a result, the T ₁ timer 75 is activated when the output of the T ₀ timer 72 changes from “1” to “0”, and outputs “1” during the period of T ₁ , and then becomes “0”.

The output of the T ₁ timer 75 is fed back to the first differentiating circuit 71 which activates the T ₀ timer 72 through the second inverting logic gate 76 and the AND gate 77 of the charge control information. As a result, when the charging instruction is designated, the T ₀ timer 72 outputs an output which repeats “1” during the period of T ₀ and “0” during the period of the subsequent T ₁ .

The output of the T ₀ timer 72 has two sets of AC voltage generation control signals different in phase from each other by approximately 1/2 cycle because the inverter circuit 20 generates an AC voltage, and AND gates 78 and 79 respectively perform AND logic processing. Then, the gate control signals of the two pairs of switching transistors 21, 24 and 22, 23 formed by combining them in a bridge shape are generated and transmitted to the inverter circuit 20.

As a result, in the inverter circuit 20, the alternating electromagnetic field is continuously generated for the period of T ₀ , and the subsequent T ₁
The generation of the AC electromagnetic field is stopped during the period of, and this state is repeated.

The generation of the period T ₀ for continuously generating the AC electromagnetic field does not necessarily have to be performed by a timer such as a monostable multivibrator, and the generation cycle of the AC voltage is based on the cycle of the AC voltage. It may be implemented by means of calculating and controlling by a counter.

FIG. 4 shows a charging monitoring control circuit 56 for transmitting the charging monitoring control information of the secondary battery 53 from the inside of the body to the outside of the body during the period in which the AC electromagnetic field generated for charging from the outside of the body is stopped. 2 shows an example of a charge monitoring control information transmission signal generation circuit provided in the.

The charging AC electromagnetic field from the outside of the body is received by the power receiving coil 52 inside the body shown in FIG.
An alternating voltage is induced there. Then, the AC voltage is rectified by the power receiving rectifier circuit 60, and the secondary battery 53 is charged through the smoothing filter including the smoothing capacitor 65 and the current monitoring resistor 54.

However, the DC voltage rectified by the power receiving rectifier circuit 60 has four rectifying diodes 61.
Due to the characteristics of .about.64 and a slight imbalance in circuit mounting, minute rectification noise corresponding to the positive polarity and the negative polarity of the AC voltage is superimposed as a ripple.

Therefore, the circuit shown in FIG. 4 receives the rectified voltage as an input, amplifies, for example, only the positive component of the ripple superimposed on the rectified voltage, and integrates it over time to obtain a ripple accompanying the reception of the charging AC electromagnetic field. During the period (T ₀ ) during which the output is “1”, the charging AC voltage generation period detection circuit 80 and the charging monitoring control information are displayed within the period T ₁ after the continuous generation of the charging AC electromagnetic field is stopped. The transmission timing determining circuit 90 determines the transmission timing for performing telemetry transmission to the outside of the body.

In the charging AC voltage generation period detection circuit 80, the rectified voltage input terminal has a capacitance 8 connected in series.
1 is connected to the base of the first-stage transistor 82.

As a result, the DC component of the rectified voltage is removed, and the ripple component superimposed on the rectified voltage is removed by the transistor 8
It is input to the base of 2. A direct current bias voltage obtained by dividing the difference between the power supply voltage of the circuit and the ground potential by two resistors is applied to the base of the transistor 82.

The collector output of the transistor 82 in the first stage is inverted and amplified by the ripple applied to the base and becomes 2
It is input to the base of the transistor 83 of the stage. Two
To the base of the transistor 83 of the first stage, a DC bias potential is applied by dividing the power supply voltage with a resistor having a resistance higher than the resistance value of the collector load resistance of the transistor 82 of the first stage, and the output of the transistor 82 of the first stage is applied to it. Are superimposed and input.

At the collector output of the second stage transistor 83, the inverted and amplified amplified ripple output applied to the base is further inverted and amplified. Ie 2
The collector output of the transistor 83 in the second stage has a voltage amplitude in which the ripple applied to the base of the transistor 82 in the first stage is amplified by a factor corresponding to the product of the amplification factors of the transistors 82 and 83.

The polarity of the output is the same as the polarity of the input ripple, but since the emitter potential of the transistor 83 in the second stage is the ground, no negative potential is generated. That is, under an appropriate DC bias supplied to the base, an output in which only the ripple component corresponding to the positive polarity is amplified can be obtained as the collector output.

This output has a positive polarity output according to the generation period of the AC electromagnetic field while the AC electromagnetic field is intermittently generated, and no ripple is generated while the AC electromagnetic field is not generated. Therefore, the output according to the ripple does not occur.

A resistor 84 and an electrostatic capacitance 85 are connected in series to the collector of the transistor 83 of the second stage, and a circuit for detecting the potential due to the charges accumulated in the electrostatic capacitance 85, that is, an integrating circuit is provided. It is configured.

The resistor 84 and the capacitance 85 of the integrating circuit are
The integration constant, which is determined by the product of the resistance value and the electrostatic capacitance value, is set to have a value sufficiently larger than the cycle of the alternating electromagnetic field generated intermittently.

Therefore, the output from the integrating circuit is "1" during the period (T ₀ ) in which the alternating electromagnetic field is generated intermittently, and is output while the alternating electromagnetic field is not generated. Since it becomes "0", the AC voltage generation period can be detected.

The output of the AC voltage generation period T ₀ detected by the AC voltage generation period detection circuit 80 is input to the transmission timing determination circuit 90, and the inverting logic gate 91 and the differentiating circuit 92 are provided.
It is input to the T ₁ timer 93 and the delay pulse generating circuit 94 via.

Here, due to the functions of the inverting logic gate 91 and the differentiating circuit 92, there is an appropriate time for carrying out a process of reading information from a register or the like not shown, with the end point of the AC voltage generation period as a starting point. , Is set based on the output of the delay pulse generation circuit 94.

Since this period must be during the period (T ₁ ) in which a predetermined AC electromagnetic field is not generated, the AND gate is set so that the output of the T ₁ timer 93 is output during the period of "1". The logical processing by 95 is performed.

In this way, the generation period (T ₀ ) of the charging AC electromagnetic field from the outside of the body is synchronously determined by the charging AC voltage generation period detection circuit 80, and the charging AC electromagnetic field is generated. After being stopped, the charge monitoring control information accumulated in the register or the like is read at an appropriate time determined by the transmission time determination circuit 90 during the period T ₁ , and a signal to be transmitted by the telemeter is generated.

FIG. 5 is a diagram conceptually showing the relationship between the electromotive voltage of the secondary battery 53 and the charging current of the secondary battery 53. The state of the secondary battery 53 in the initial state is a fully charged state, but when the load is operated for a long period of time, the electric charge stored in the secondary battery 53 is gradually discharged, and the secondary battery 53 is discharged.
The electromotive voltage of is reduced. Therefore, for example, the electromotive voltage of the secondary battery 53 is measured every time a certain period of time elapses, and charging is carried out when the discharge is progressing above a predetermined value.

FIG. 5 shows the relationship between the electromotive voltage of the secondary battery 53 and the charging current when the secondary battery 53 is charged at a constant voltage. At the beginning of charging, the secondary battery 53 is in the state of being discharged, and the electromotive voltage of the secondary battery 53 is lowered. Therefore, the power supply voltage for charging the secondary battery 53 and the electromotive voltage of the secondary battery 53 are The difference is large and the charging current is large. However, since the electromotive voltage of the secondary battery 53 gradually increases as the degree of charging progresses, the difference between the power supply voltage and the electromotive voltage of the secondary battery 53 gradually decreases, and the charging current decreases.

Further, in the figure, the relationship between the electromotive voltage of the secondary battery 53 and the charging current when the secondary battery 53 is charged with a constant current is shown. Since the charging current is constant, the electromotive voltage of the secondary battery 53 increases as the degree of charging progresses.

Point P in FIG. 5 is the point where charging is completed, and if charging continues beyond this point, overcharging will occur, and there is a danger of characteristic distortion of the secondary battery 53 itself and damage to other parts.
This is a state in which the charging operation is completed. The charging completion point can be determined by the electromotive voltage of the secondary battery 53 or the like.

FIG. 6 shows the relationship between the progress of the degree of charge and the charge control information regarding the charge control of the secondary battery 53. The charging AC electromagnetic field from the outside of the body is transmitted in bursts every period of T ₀ , and the secondary battery 53 is transmitted every period of this period.
Is charged. When the power transmission period ends, the generation of the AC electromagnetic field is stopped and the power transmission is stopped during the period T ₁ .

During this period of T ₁ , the charge monitoring control circuit 56
Measures the electromotive voltage of the secondary battery 53, performs a comparison calculation with a preset charging completion voltage, and outputs it to the telemetry transmission circuit 57 for telemetry transmission as charging control information.

When the electromotive voltage of the secondary battery 53 is equal to or lower than the charge completion voltage, the charge control information becomes "1", and the charge instruction for continuously executing the generation of the charging AC electromagnetic field for the next period. Is transmitted.

When the burst-like power transmission for charging is repeatedly performed to some extent and the electromotive voltage of the secondary battery 53 reaches the charge completion voltage, the charge control information becomes "0", and after the next period. A signal indicating a charging stop instruction for stopping the generation of the charging AC electromagnetic field.

The generation of the charging control information does not necessarily have to be performed by the charging monitoring control circuit 56 of the living body implanting device, and the charging monitoring information such as the electromotive voltage of the secondary battery 53 is received outside the body by telemetry and the inverter is used. Control circuit 3
Alternatively, the charging control information may be generated in step 4 or the like.

FIG. 7 shows the relationship between the applied pulse output from the inverter control circuit 34 to the gates of the switching transistors 21 to 24 of the inverter circuit 20 corresponding to the charge control information and the output voltage of the inverter circuit 20. ing.

When the inverter control circuit 34 receives the charging instruction information having the charging control information of "1", the inverter circuit 2
Inverter control circuit so that the pulses applied to the gates of two pairs of switching transistors 21, 24 and 22, 23, which are combined in a bridge shape of 0, have a duty of approximately 0.5 and the pair of transistors are conductive in a complementary manner. Three
It is output from 4. As a result, the inverter circuit 20 intermittently outputs the AC voltage for charging in a burst manner.

When the inverter control circuit 34 receives the charge stop information of which the charge control information is "0", the inverter circuit 2
The inverter control circuit 34 controls so as to stop the pulse application to the gates of the transistors 21 to 24 so that both of the two switching transistor pairs 21, 24 and 22, 23 of 0 are non-conductive. Then, the inverter circuit 20 stops the generation of the AC voltage for charging.

FIG. 8 shows a comparison result of the charging current monitoring information of the secondary battery 53, in which the potential difference between both ends of the current monitoring resistor 54 having a known resistance value is compared with the potential corresponding to the predetermined charging current value. It is shown as digital information.

During the continuous burst-like charging period T ₀ , the potential difference generated across the current monitoring resistor 54 can be measured by, for example, a differential type operational amplifier (not shown), and the result is predetermined. The charge current value is compared with the potential corresponding to.

FIG. 8 shows the comparison result as 3-bit digital information, and is an example in which MSB (Most Significant Bit) is used as a code bit.

Here, if the charging current value is larger than the predetermined charging current value, it is set to "1", and conversely, if it is smaller, it is set to "0", and the other two bits are set to the difference from the predetermined charging current value. It is displayed according to. These charging current monitoring information are
Telemetry is transmitted to the outside of the body during the period T _{1 when} charging is stopped.

In order to charge the secondary battery 53 with a predetermined current value, the charging control circuit 35 uses the transformer circuit to increase or decrease the intensity of the burst-like AC electromagnetic field in the next period based on this monitoring information. By controlling the conduction period of the switching transistors 12 of 10, the transformer circuit 1
This is performed by changing the output voltage of 0.

In the example shown in FIG. 8, the case where the difference between the predetermined current value and the predetermined current value is used as the monitoring information of the charging current is shown as 3-bit digital information. The output voltage of the transformer circuit 10 is increased more than necessary so as to obtain a predetermined charging current value when the charging current is significantly smaller than the expected current value in a certain range due to the positional relationship with the implantation device being displaced. This may adversely affect the living body, damage electronic circuits, or cause malfunctions.

Therefore, when the charging current monitoring information is less than the charging current lower limit value, the alarm instruction control information is generated and the extracorporeal device is provided with means for displaying the information.
It is appropriate to stop the charging operation once, adjust the positional relationship between the power transmission coil 31 and the implanting device, and then perform the charging operation again.

FIG. 9 shows the relationship between the charging current lower limit value and the alarm control instruction information. The charging monitoring control circuit 56 compares the charging current value with the charging current lower limit value, and when it judges that the charging current value is less than the charging current lower limit value, generates the alarm control instruction information as “1”. The information is transmitted to the telemetry transmission circuit 57.
Is transmitted from the outside to the outside of the body, and the outside-body display / alarm / operation circuit 36 performs the alarm display based on the received alarm control instruction information.

The alarm control instruction information in which the charging current value and the charging current lower limit value are compared does not necessarily have to be generated by the charging monitoring control circuit 56 of the implanting device, but may be generated outside the body.

[0087]

According to the present invention, in carrying out transcutaneous charging of a battery implanted in a living body, an AC electromagnetic field is intermittently generated from the outside of the body to generate an AC current for charging. Charging control from the battery embedded in the body is performed by transmitting the charging monitoring control information of the internal battery to the outside of the body while the generation of the electromagnetic field is stopped and performing the charging control based on this information. The monitoring control information can be accurately extracted without being disturbed by the AC electromagnetic field when charging the battery. As a result, the charging monitoring information and the charging control information can be obtained without error when charging the battery implanted in the living body implanting device, so that there is an excellent effect that the charging operation can be performed safely.

If constant voltage charging is performed with the electromotive voltage of the battery as a reference, it can be determined whether the charging should be continued or terminated only by the electromotive voltage of the battery, so that the charging control can be easily performed and the charging current value can be increased. If constant-current charging is performed to keep constant, the charging current value does not become excessive, and there is no risk of deterioration of battery quality.

Further, by issuing an alarm when the charging current value does not reach the predetermined value, it is possible to know the positional deviation between the extracorporeal charging device and the implanting device and prevent the occurrence of adverse effects on the living body. it can.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment.

FIG. 2 is a diagram illustrating a charging AC electromagnetic field (voltage) of an example.

FIG. 3 is a circuit diagram of a charging AC voltage generation control circuit according to an embodiment.

FIG. 4 is a circuit diagram of a charge monitoring control information transmission signal generation circuit of the embodiment.

FIG. 5 is a diagram showing a relationship between an electromotive voltage and a charging current of the secondary battery of the example.

FIG. 6 is a diagram showing the relationship between the degree of charge of the secondary battery and the charge control information according to the embodiment.

FIG. 7 is a diagram showing the relationship between the output of the inverter control circuit (gate application pulse) and the output voltage of the inverter circuit with respect to the charging control information of the embodiment.

FIG. 8 is a diagram showing charging current monitoring information of the secondary battery of the example.

FIG. 9 is a diagram showing a relationship between a charging current lower limit value and alarm instruction control information according to the embodiment.

[Explanation of symbols]

 10 Transformer circuit 20 Inverter circuit 33 Telemetry receiving circuit 34 Inverter control circuit 35 Charging control circuit 53 Secondary battery 54 Current monitoring resistor 56 Charging monitoring control circuit 57 Telemetry transmission circuit 60 Rectification circuit for power reception

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mari Okazaki 1500 Inoguchi, Nakai-cho, Ashigarashie-gun, Kanagawa Prefecture Cardio Pacing Research Laboratory Co., Ltd. (72) Masafumi Mashima Inoguchi, Nakai-cho, Ashigagami-gun, Kanagawa 1500 Car Corporation Geopacing Research Laboratory (72) Inventor Katsuya Hirachi 1500 Inoguchi, Nakai-cho, Ashigaragami-gun, Kanagawa Prefecture Car Geopacing Research Laboratory (72) Inventor Koji Kuwana 1500 Inoguchi, Nakai-cho, Ashigagami-gun, Kanagawa Car Geopacing Research Laboratory

Claims (4)

[Claims] 1. A battery embedded in a living body for supplying electric energy to a device implanted in the living body,
A transcutaneous charging unit for transcutaneously transmitting the AC electromagnetic field for charging the battery in the living body outside the body, and monitoring the charging status of the battery in the living body, A charging status monitoring means for transcutaneously transmitting charging monitoring information to the outside of the body, and the charging monitoring information sent from the charging status monitoring means outside the body, and the transcutaneous charging according to the content of the signal. In a percutaneous charging device for a living body implanting device having a charging control means for controlling the operation of the means, the percutaneous charging means intermittently generates an AC electromagnetic field for charging the battery, and the AC electromagnetic field is A percutaneous charging device for a living body implanting device, characterized in that charging monitoring information is transmitted and received between the charging status monitoring means and the charging control means during a time when the charging is not occurring. 2. The charging control means intermittently generates an AC electromagnetic field in the transcutaneous charging means when the electromotive voltage of the battery does not reach a predetermined voltage as a result of monitoring by the charging status monitoring means, 3. The transcutaneous charging means stops the generation of an alternating electromagnetic field when the electromotive voltage of the battery reaches a predetermined voltage.
A percutaneous charging device for a living body implantation device as described above. 3. The charge control means, if the electromotive voltage of the battery does not reach a predetermined voltage as a result of monitoring by the charge status monitoring means, depending on the magnitude of the difference between the charge current value and the predetermined value. The transcutaneous charging device for a living body implanting device according to claim 1, wherein the intensity of the alternating electromagnetic field is controlled so that the charging current value becomes the predetermined value. 4. The alarm generation means for issuing an alarm when the charging current for the battery does not reach a predetermined value as a result of the monitoring by the charging status monitoring means.
A percutaneous charging device for a living body implanting device as described above.