JPH0445192B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a defibrillation device that can measure discharge energy delivered from a capacitor to a patient through a damping coil. [Prior art] This type of device is USPat.No. 3860009, the energy delivered to the patient by the discharge of a capacitor is determined by calculations based on the values detected by a current monitor inserted in series with the discharge circuit and a voltage monitor in parallel with the load resistor. Desired. Furthermore, in the March 1978 issue of Medical and Biological Engineering and Computing (Med. & Biol. Eng. & Comp.), pages 169 to 178, the peak value of the discharge current of a capacitor is detected, A method for determining the load resistance and the delivered energy from the peak value is also described. [Problems to be Solved by the Invention] However, in the former case, it is not only necessary to separately connect a current monitor to the discharge circuit in order to measure the transmitted energy, but also when an electric particle transformer is used as the current monitor, There is also a problem in measurement accuracy due to the influence of leakage magnetic flux from a damping coil for shaping the discharge waveform that is normally inserted in the discharge circuit. On the other hand, if a small resistance is used for the current monitor in order to avoid this problem, power loss increases accordingly. Furthermore, with the latter method of detecting the peak value, it is difficult to improve the measurement accuracy of load resistance and energy. Therefore, it is an object of the present invention to provide a defibrillation device that picks up the leakage magnetic flux of a damping coil without using a current monitor and always measures the delivered energy with high accuracy regardless of the load resistance value. purpose. [Means for Solving the Problem] In order to achieve this object, the present invention is attached to a damping coil so as to interlink a part of the magnetic flux generated by the coil, and the voltage is increased by a change in the interlinking magnetic flux. A pick-up coil that generates a signal, a unipolar integrating means that integrates only the differential output signal of one polarity of the pick-up coil, and a charging voltage of the capacitor and an integrated output signal of the unipolar integrating means after the capacitor is discharged. Load resistance detection means detects the load resistance by taking in the charging voltage and integral output signal by having a table stored in advance in memory that specifies the load resistance of the patient, and a damping coil based on the charging voltage and the detected load resistance. The device includes a delivered energy calculation means for calculating the energy actually delivered to the patient by correcting the loss due to the internal resistance of the patient, and an output means for displaying or recording the energy. [Operation] During discharge of the capacitor, the unipolar integrating means integrates only one polarity component of the output signal from the pickup coil, thereby generating an integrated output signal corresponding to the total amount of interlinkage magnetic flux in one direction. The load resistance detection means detects the load resistance exhibited by the patient based on the integrated output signal and the charging voltage signal corresponding to the charging voltage of the capacitor, and detects the known internal resistance of the damping coil based on the load resistance and the charging voltage signal. The amount of energy delivered to the patient is calculated by correcting the loss, and the delivered energy is confirmed by the output means. Embodiment of the Invention FIG. 1 shows a defibrillation device according to an embodiment of the invention. In the figure, when a switch 2 is turned on, the high voltage charged in a capacitor 1 by a high voltage source 10 is discharged through a damping coil 3 and through paddles 4, 4a set on a patient. The basic circuit of such a defibrillator is
According to the present invention, in order to calculate the energy sent from the capacitor 1 to the patient, a part of the magnetic flux generated by the damping coil 3 that is attached to the damping coil 3 is interlinked, and the interlinked magnetic flux φ(t) (Fig. 2 a) A pickup coil 5 that generates an output signal differentiated with respect to time, and a unipolar integral that integrates only the differential output signal e=dφ/dt (FIG. 2b) of one of the polarities of this pickup coil, e.g., +. Integral output signal Ф _{+ =} ∫(dФ/
dt) It has a table stored in advance in memory that specifies the load resistance R _L exhibited by the patient from the ratio of dt, and detects the load resistance R _L by taking in the charging voltage (V _C ) signal and the integral output signal Ф ₊ . load resistance detection means 7;
A delivery energy calculating means 8 that calculates the delivery energy E _D actually delivered to the patient by correcting the loss due to the internal resistance R of the damping coil 3 from the V _C signal and the detected load resistance R _L ; An output means 9 for displaying or recording is attached. The load resistance detection means 7 calculates the calculated value of Ф ₊ /V _C as described above on the assumption that the inductance L of the damping coil 3, its internal resistance R, and the capacitance C of the capacitor 1 are known from the following relationship. It can be seen that the load resistance R _L can be specified by comparing it in the table. In the following equation, Ф ₊ is the integral value of the period during which the interlinking magnetic flux of the pickup coil 5 increases, and V _C is also the actual charging voltage itself. Let D=(R+R _L /L) ² -4/LC. (1) In case of overbraking, D>O (dotted line in Figure 3) shall be. (2) In the case of insufficient braking, D<O (solid line in Figure 3), a=α+jβ b=α−jβ, then α=R+R _L /2L

〔Effect of the invention〕

As described above, according to the present invention, the transmitted energy corresponding to the load resistance can be detected using the leakage magnetic flux without inserting a current monitor in series with the damping coil in the discharge circuit, and there is no influence of the leakage magnetic flux. Also, since it relies on the flux linkage integration method, highly accurate detection is always possible regardless of the discharge characteristics associated with changes in load resistance. Furthermore, compared to the conventional method of detecting the peak value of the discharge current of the capacitor and determining the load resistance and the delivered energy from that value, the present invention can be applied within a predetermined resistance value range (R _L

Claims (1)

[Scope of Claims] 1. A defibrillation device that discharges high voltage charged in a capacitor to a patient through a damping coil, which is attached to the damping coil so that a part of the magnetic flux generated by the coil interlinks with the damping coil. , a pick-up coil that generates a voltage as this interlinkage magnetic flux changes; unipolar integrating means that integrates only the differential output signal of one polarity of the pick-up coil; and a voltage at which the capacitor is charged and after the capacitor is discharged The load resistance is detected by taking in the charging voltage and the integral output signal by having a table stored in a memory in advance that specifies the load resistance of the patient based on the integral output signal of the unipolar integrating means. load resistance detection means; delivery energy calculation means for calculating the energy actually delivered to the patient by correcting loss due to internal resistance of the damping coil from the charging voltage and the detected load resistance; an output means for displaying or recording;
A defibrillation device comprising: