SU599812A1 - External cardiostimulator - Google Patents

Description

The pulse generator 1 generates a sequence of pulses, which is fed to the input of the key 2. During a pause, the jA IJ III key 2 is closed, the capacitor 4 is discharged to zero voltage, and rezstor 3, the diode 14 n load 21 is de-energized. When this transistor 11 is closed, the tunnel diode 12 is de-energized, the transistor 10 is closed and the diode 13 is de-energized.

During the duration of the pulse arriving at the input of the key 2, the latter opens n through the capacitor 4 into the load 21 (i.e., into the heart) a stimulating impulse arrives. At the same time, the base of the transistor 11 receives pulses of the enabling polarity from the diode 14 through the resistor 16 and from the clamp 7 through the resistor 17.

If the voltage of the power source (battery) is of a detour and in the electrode circuit of the short circuit loop, then the incoming pulses of the base of the transistor And the pulses saturate it, current flows through the resistor 18, the tunnel diode 12 switches to the high voltage state, the transistor 10 is saturated, through the current-limiting the resistor 20 and the LED 13 are flowing, causing the LED 13 to glow, the right side of the capacitor 15 is under the potential of the common ground 9 and a current is flowing through the resistor 19 to the base of the transistor 11, supporting it in staying saturated. As the capacitor 15 charges, the base current of the transistor 11 decreases, transistor 11 goes out of saturation, which leads to switching the tunnel diode 12 to the low voltage state, closing the transistor 10 and then the transistor I. The duration of the LED 13 is determined by the value of the time constant the capacitor 15 and the resistor 19 and is

20 ... 50 ms, which is necessary for confident observation of the LED strip 13 LEDs.

Thus, at the nominal value of the voltage of the power source and the normal state of the electrode circuit, the rhythm of the pacemaker is monitored by flashing of the LED 13 pa each entering the load

21 stimulating impulse.

If the voltage of the power source becomes less than a predetermined level (battery discharge), although transistor 11 is saturated, however, tunnel diode 12 does not switch to the high voltage state and therefore transient 10 does not open, and LED 13 does not flash. The voltage level of the power supply at which the switching of the tunnel diode 12 (battery voltage) occurs is determined by the values of the peak current of the tunnel diode 12 and the resistance of the resistor 18.

If the resistance of the electrode circuit becomes abnormally small (short circuit in the electrode circuit), then the amplitude of the voltage pulse coming from terminal 7 through the resistor 17 on the base of the transistor I turns out to be insufficient

To open the latter and no ioiiy m}, the diode 12 ne does not switch, the trapsietor 10 does not open, and the LED 13 does not flash. The resistance of the electrode circuit is composed of the resistance of the electrodes of 50 ... 150 ohms and the resistance of the fabric between the iroximal ends of the electrodes, which is considered to be equal in size to 500 O.VI. If the resistance of the electrode circuit

it turns out to be less than 50 ... 100 ohms, this means that the electrode system is out-of-equiporate (short circuit mode). With typical values of emulation current 2 ... 10 mA, the voltage pulse amplitude on terminal 7, corresponding to the short circuit mode in the electrode circuit, is 0.1 ... 1.0 volts. The threshold for unlocking the transistor I corresponding to the indicated boundary is established by means of a diode 14 and a resistor 16.

Since the signal is removed from the output terminals 6 and 7, it simultaneously controls the operation of all the pacemaker assemblies up to and including the output terminals. In this case, since the threshold for opening the transistor 11

is set using a diode 14 and a resistor 16, the value of the resistance of the resistor 17 can be chosen sufficiently large, for example, more than 100 com. Therefore, even in the case of a sudden failure of the transistor 11, the direct current through the load 21 (i.e., through the heart) will be limited at a safe level, and the number is 10 μA. As a result, the patient is guaranteed safety from electropooric direct current in case of a sudden failure of any component of the circuit.

Claims (1)

Invention Formula A paired pacemaker containing a pulse generator, a key on a Pr-p transistor of conductivity type, assembled according to a common emitter circuit and a power source, characterized in that, in order to ensure the possibility of monitoring the health of both the whole pacemaker and its individual nodes, and also detecting the short circuit of the electrode circuit, introduced two transistors pnp and ppp conduction types, a tunnel diode, a led and a diode, a capacitor and five resistors, through one of which the base of the transistor ppn type of conduct The connections to the output of the switch, where the connection point of the collector resistor and the cathode of the DND, the anode of which is connected to the power source, is connected via another resistor to the base of this transistor and then connected to the collector of the second transistor -nnp conduction, which is connected through a circuit of successively connected resistors and directly connected LEDs to the plus of the input terminal, in addition, the emitter of the second traizistor directly The base of the first transistor is connected to the anode of the tunnel diode through a resistor, and its emitter is connected to the positive power source. Informanine medical notes taken into account during the examination 1. US Patent No. 3433228, cl. 128-422. op glare. 1969.