Defibrillator

Abstract

To provide a defibrillator capable of using a component having a lower withstand voltage than a conventional one while satisfactorily maintaining an original operation as the defibrillator.SOLUTION: The defibrillator of the present disclosure is a defibrillator including an H-bridge type biphasic pulse forming circuit connected to a rear stage side of a high-voltage capacitor, the biphasic pulse forming circuit including a first switching unit, a second switching unit connected in parallel to the first switching unit, a third switching unit connected in series to a rear stage side of the first switching unit, and a fourth switching unit connected in series to a rear stage side of the second switching unit, A biphasic pulse is output from a first output line connected to a connection midpoint between the first switching unit and the third switching unit and a second output line connected to a connection midpoint between the second switching unit and the fourth switching unit. In at least one of the first to fourth switching units, a plurality of thyristors are connected in series, and a resistor is connected in parallel to each of the plurality of thyristors.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to defibrillators. [Background technology]

[0002] A defibrillator is a medical device that delivers an electric shock to a patient whose heart has gone into ventricular fibrillation and is no longer able to pump blood around the body, thereby eliminating the fibrillation and restoring the heart's function to normal.

[0003] A defibrillator generates a high voltage internally, charges a capacitor with the voltage, and then discharges it to electrode pads or paddles attached to the patient, thereby delivering an electric shock to the patient.

[0004] The configuration of a discharge unit in a defibrillator is described, for example, in Patent Documents 1 and 2. Because a defibrillator discharges a high voltage, high-voltage components are used in the switching unit that controls the discharge. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2020-503916 [Patent Document 2] Special Publication No. 2008-514330 Summary of the Invention [Problem to be solved by the invention]

[0006] Defibrillation voltages can reach a maximum of approximately 2000 V. Therefore, the discharge unit that discharges the defibrillation voltage is constructed with high-voltage components. Furthermore, when outputting biphasic pulses from the discharge unit, the discharge unit is configured to have multiple high-voltage switching units. This results in a more complex configuration and increased product costs.

[0007] In particular, it is desirable to manufacture as many defibrillators as possible, such as AEDs (Automated External Defibrillators), and to spread them widely throughout society, so there is a demand for reducing the cost of the products.

[0008] The present disclosure has been made in consideration of the above points, and provides a defibrillator that can use components with lower voltage resistance than conventional defibrillators while maintaining the original operation of the defibrillator well. [Means for solving the problem]

[0009] One aspect of the defibrillator of the present disclosure comprises: A defibrillator having an H-bridge type biphasic pulse forming circuit connected to the rear side of a high-voltage capacitor, The biphasic pulse forming circuit comprises: a first switching unit; a second switching unit connected in parallel to the first switching unit; a third switching unit connected in series to a downstream side of the first switching unit; a fourth switching unit connected in series to a downstream side of the second switching unit; and outputs a biphasic pulse from a first output line connected to a connection midpoint between the first switching unit and the third switching unit, and a second output line connected to a connection midpoint between the second switching unit and the fourth switching unit, At least one of the first to fourth switching units A plurality of thyristors are connected in series, and a resistor is connected in parallel to each of the plurality of thyristors.

[0010] One aspect of the defibrillator of the present disclosure comprises: A defibrillator having an H-bridge type biphasic pulse forming circuit connected to the rear side of a high-voltage capacitor, The biphasic pulse forming circuit comprises: a first switching unit; a second switching unit connected in parallel to the first switching unit; a third switching unit connected in series to a downstream side of the first switching unit; a fourth switching unit connected in series to a downstream side of the second switching unit; and outputs a biphasic pulse from a first output line connected to a connection midpoint between the first switching unit and the third switching unit, and a second output line connected to a connection midpoint between the second switching unit and the fourth switching unit, At least one of the first to fourth switching units It has a configuration in which multiple IGBTs (Insulated Gate Bipolar Transistors) are connected in series, a plurality of branch signal lines branching from a common signal line from a control unit are connected to the gates of the plurality of IGBTs; The signal delay amount of the branch signal line connected to the IGBT in the front stage among the plurality of IGBTs is larger than the signal delay amount of the branch signal line connected to the IGBT in the rear stage among the plurality of IGBTs. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to realize a defibrillator that can use components with lower voltage resistance than conventional ones while maintaining the original operation of the defibrillator well. [Brief explanation of the drawings]

[0012] [Figure 1] A circuit diagram showing a schematic configuration of a defibrillator according to an embodiment. [Figure 2] A circuit diagram showing an example of the configuration of a defibrillator according to a comparative example. [Figure 3] This diagram explains the ON / OFF operation of the switching section of the biphasic pulse forming circuit of a defibrillator. [Figure 4] As a reference example, a diagram showing a simple configuration in which two thyristors are connected in series [Figure 5]This diagram shows the potential and voltage values ​​when the thyristor is turned on and off in the case where the configuration of Figure 4 is adopted. [Figure 6] FIG. 1 is a diagram showing a first example of the configuration of a portion related to a thyristor according to the present embodiment. [Figure 7] This is a diagram showing the potential and voltage values ​​when the thyristor is turned on and off in the case where the configuration of Figure 6 is adopted. [Figure 8] FIG. 2 is a diagram showing a second example of the configuration of a portion related to a thyristor according to an embodiment; [Figure 9] Circuit diagram when thyristor SCR1 is considered as variable resistor r1 in configuration example 2 [Figure 10] A rewritten version of the structure in Figure 9 [Figure 11] FIG. 10 is a diagram showing a state of voltage rise immediately after a shift in ON timing in the configuration of the embodiment. [Figure 12] Diagram showing an LCR series circuit [Figure 13] Figure showing the time response of voltage distribution of each element based on the solution of the differential equation [Figure 14] Figure showing the time response of voltage distribution of each element based on the solution of the differential equation [Figure 15] FIG. 1 is a diagram showing a configuration example of a portion related to an IGBT according to an embodiment; [Figure 16] FIG. 1 is a diagram showing a configuration example of a portion related to an IGBT according to an embodiment; [Figure 17] Circuit diagram showing the configuration of another embodiment [Figure 18] Circuit diagram showing the configuration of another embodiment DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0014] <1> Outline configuration 1 is a circuit diagram showing a schematic configuration of a defibrillator 100 according to an embodiment of the present disclosure. In particular, FIG. 1 is a circuit diagram showing a circuit portion related to charging and discharging energy of the defibrillator 100.

[0015] The defibrillator 100 has a primary circuit 100a and a secondary circuit 100b. The primary circuit 100a includes a battery 11, a power MOSFET 12, a resistor 13, and the like. The primary circuit 100a and the secondary circuit 100b are connected by a transformer 14, which outputs a high voltage (for example, approximately 2000 [V] to 2300 [V] in the case of a biphasic pulse) to the secondary circuit 100b. Specifically, while the power MOSFET 12 is ON, power is stored in the transformer 14, which has a winding N1 and a secondary winding N2. When the power MOSFET 12 is switched OFF, the back electromotive force of the transformer 14 is used to output the stored power to the secondary circuit 100b in one go.

[0016] The power output from the transformer 12 is charged into a large-capacity high-voltage capacitor 16 via a rectifier circuit 15. The high-voltage capacitor 16 is capable of storing a charge of a high voltage (e.g., 2000 V) compared to the voltage of the battery 11 (e.g., 24 V).

[0017] A biphasic pulse forming circuit 110 is connected downstream of the high-voltage capacitor 16. The biphasic pulse forming circuit 110 is configured to output a pulse of a first phase and then a second pulse of the opposite phase. This allows defibrillation to be performed with lower energy and without inducing new ventricular fibrillation, compared to defibrillators that output monophasic pulses.

[0018] The biphasic pulse forming circuit 110 of this embodiment is configured with an H-bridge type circuit. As described in Patent Documents 1 and 2, H-bridge circuits are often used as biphasic pulse forming circuits in defibrillators.

[0019] The biphasic pulse forming circuit 110 has a first switching unit 111, a second switching unit 112 connected in parallel to the first switching unit 111, a third switching unit 113 connected in series to the rear stage side of the first switching unit 111, and a fourth switching unit 114 connected in series to the rear stage side of the second switching unit 114. The first to fourth switching units 111 to 114 are ON / OFF controlled by control signals from the control unit 120.

[0020] Furthermore, in the biphasic pulse forming circuit 110, an inductor 115 is connected between the high-voltage capacitor 16 and the biphasic pulse forming circuit 110.

[0021] The biphasic pulse forming circuit 110 outputs biphasic pulses from a first output line L1 connected to the connection midpoint between the first switching unit 111 and the third switching unit 113, and a second output line L2 connected to the connection midpoint between the second switching unit 112 and the fourth switching unit 114.

[0022] An energization control relay 130 is connected to the first and second output lines L1, L2 of the biphasic pulse forming circuit 110. An electrode pad / paddle 140 is connected to the downstream side of the energization control relay 130. More specifically, the connection midpoint between the first switching unit 111 and the third switching unit 113 is connected to one side of the electrode pad / paddle 140 via the energization control relay 130. The connection midpoint between the second switching unit 112 and the fourth switching unit 114 is connected to the other side of the electrode pad / paddle 140 via the energization control relay 130.

[0023] The control unit 120 also controls the ON / OFF of the current control relay 130 and the power MOSFET 12 .

[0024] FIG. 2, in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, shows an example of the configuration of a defibrillator 100' that is a comparative example to the defibrillator 100 of this embodiment. Configurations similar to the defibrillator 100' are described in, for example, Patent Documents 1 and 2. The defibrillator 100' uses high-voltage IGBTs (Insulated Gate Bipolar Transistors) as the switching units 111a to 114a. In the defibrillator 100', each of the four switching units 111a to 114a of the biphasic pulse forming circuit 110a is configured with a single high-voltage IGBT.

[0025] 2, the biphasic pulse forming circuit 110 of this embodiment shown in Fig. 1 has a first switching unit 111 configured by connecting two thyristors SCR1 and SCR2 in series, a second switching unit 112 configured by connecting two thyristors SCR3 and SCR3 in series, a third switching unit 113 configured by connecting two IGBTs IGBT3 and IGBT4 in series, and a fourth switching unit 114 configured by connecting two IGBTs IGBT1 and IGBT2 in series.

[0026] In this way, by configuring each of the first to fourth switching units 111 to 114 that make up the biphasic pulse forming circuit 110 by connecting two or more thyristors or IGBTs in series, it becomes possible to configure the first to fourth switching units 111 to 114 with inexpensive circuits that have low voltage resistance performance, compared to when each of the first to fourth switching units 111 to 114 is configured with one IGBT as shown in FIG.

[0027] That is, in a conventional circuit such as that shown in Fig. 2, each IGBT requires a high-voltage element capable of withstanding a voltage of about 2000 V, whereas in the configuration of Fig. 1, elements capable of withstanding about half that voltage can be used for each thyristor and IGBT. Therefore, in the configuration of Fig. 1, the biphasic pulse forming circuit 110 can be configured using low-voltage components compared to the configuration of Fig. 2, and the product cost can be reduced compared to the conventional configuration.

[0028] Incidentally, when comparing the number of components constituting the first to fourth switching units of the biphasic pulse shaping circuits, the biphasic pulse shaping circuit 110 of the present embodiment shown in FIG. 1 requires a total of eight components, including four thyristors and four IGBTs, whereas the conventional biphasic pulse shaping circuit 110a shown in FIG. 2 requires only four IGBTs. Therefore, the biphasic pulse shaping circuit 110 of the present embodiment requires approximately twice the number of components as the conventional biphasic pulse shaping circuit 110a. However, components with a withstand voltage specification of, for example, about 1000V are readily available and therefore can be obtained at a cost far lower than half the cost of components with a withstand voltage specification of 2000V or higher, thereby reducing total product costs. Therefore, although the configuration of the present embodiment requires more components than the conventional configuration, product costs are lower.

[0029] FIG. 3 is a diagram illustrating an example of the ON / OFF operation of the switching units 111 to 114 of the biphasic pulse forming circuit 110 of the defibrillator 100. As shown in FIG.

[0030] When defibrillation is stopped (i.e., when the power supply of the defibrillator 100 is turned off) and during charging (i.e., when defibrillation energy is being charged into the high-voltage capacitor 16), IGBT1 and IGBT2, which constitute the fourth switching unit 114, are turned on, and SCR1 and SCR2, which constitute the first switching unit 111, SCR3 and SCR4, which constitute the second switching unit 112, and IGBT3 and IGBT4, which constitute the third switching unit 113, are turned off. As a result, no current flows through the biphasic pulse forming circuit 110 when defibrillation is stopped or during charging.

[0031] Defibrillator 110 transitions to an energized state when charging is complete. The energized state includes a state in which a first phase is output (energized 1 in the figure) and a state in which a second phase opposite to the first phase is output (energized 2 in the figure). In the energized state, energization control relay 130 is controlled to be ON.

[0032] During energization 1, SCR1 and SCR2, which are the first switching unit 111, are controlled to change from OFF to ON. As a result, the charge stored in the high-voltage capacitor 16 flows in the following order: first switching unit 111 (SCR1, SCR2) → energization control relay 130a → first electrode 140a of electrode pad / paddle 140 → second electrode 140b of electrode pad / paddle 140 → energization control relay 130b → fourth switching unit 114 (IGBT1, IGBT2) → ground.

[0033] During energization 2, SCR1 and SCR2, which are the first switching unit 111, are controlled to change from ON to OFF, SCR3 and SCR4, which are the second switching unit 112, are controlled to change from OFF to ON, IGBT1 and IGBT2, which are the fourth switching unit 114, are controlled to change from ON to OFF, and IGBT3 and IGBT4, which are the third switching unit 113, are controlled to change from OFF to ON. As a result, the charge stored in the high-voltage capacitor 16 flows in the following order: second switching unit 112 (SCR3, SCR4) → energization control relay 130b → second electrode 140b of electrode pad / paddle 140 → first electrode 140a of electrode pad / paddle 140 → energization control relay 130a → third switching unit (IGBT3, IGBT4) → ground.

[0034] In this way, the direction of the current flowing through the electrode pad / paddle 140 is opposite between energizing period 1 and energizing period 2, thereby realizing the supply of biphasic pulses to the patient.

[0035] When a first phase pulse is output, the fourth switching unit 114 is turned ON and then the first switching unit 111 is turned ON, and when a second phase pulse is output, the third switching unit 113 is turned ON and then the second switching unit 112 is turned ON.

[0036] In the defibrillator 100 of this embodiment shown in FIG. 1, each of the first to fourth switching units 111 to 114 constituting the biphasic pulse forming circuit 110 is configured with a plurality of thyristors or a plurality of IGBTs connected in series, thereby making it possible to use components with lower withstand voltages than conventional thyristors or IGBTs.

[0037] However, in a defibrillator, if each of the first to fourth switching units 111 to 114 is simply configured by connecting multiple thyristors or multiple IGBTs in series, variations in turn-on time due to variations in components, for example, may cause the thyristors or IGBTs to be damaged or to stop working. A configuration that takes this into consideration will be described below.

[0038] <2> Consideration and configuration of series connection of thyristors As a reference example, Figure 4 shows a configuration in which two thyristors SCR1 and SCR2 are simply connected in series. Note that although the configuration in which thyristors SCR1 and SCR2 are connected in series will be explained here, the same applies to a configuration in which thyristors SCR3 and SCR4 are connected in series.

[0039] Among the symbols shown on the right side of Figure 4, HV indicates the potential of the high-voltage capacitor 16 (see Figure 1), V1 indicates the potential of thyristor SCR1, V2 indicates the potential of thyristor SCR2, VSCR1 indicates the voltage applied to thyristor SCR1, and VSCR2 indicates the voltage applied to thyristor SCR2. Note that Z on the downstream side of thyristor SCR2 indicates the patient's bioimpedance.

[0040] Figure 5 is a diagram showing the potential and voltage values ​​when the thyristors SCR1 and SCR2 are turned on and off in the case of using the configuration of Figure 4. Note that Figure 5A is a diagram showing the potential, and Figure 5B is a diagram showing the voltage applied to the thyristors SCR1 and SCR2.

[0041] In Figure 5, before time t1, thyristors SCR1 and SCR2 are both OFF (corresponding to the "defibrillation stopped" and "charge" states in Figure 3), and after time t2, thyristors SCR1 and SCR2 are both ON (corresponding to the "power on (first phase outputting)" state in Figure 3).

[0042] In addition, during the period between time t1 and time t2, thyristor SCR1 is ON and thyristor SCR2 is OFF. In other words, time t1 is the timing when thyristor SCR1 is switched from OFF to ON, and time t2 is the timing when thyristor SCR2 is switched from OFF to ON.

[0043] Ideally, thyristors SCR1 and SCR2 would be turned on at the same time, but in reality, there is a slight difference in the timing at which thyristors SCR1 and SCR2 turn on. This is shown in Figure 5.

[0044] Here, since the thyristors SCR1 and SCR2 are connected in series, the voltage across the thyristor SCR1 is VSCR1=HV-V1, and the voltage across the thyristor SCR2 is VSCR2=V1-V2.

[0045] As can be seen from Figure 5B, when thyristors SCR1 and SCR2 are both OFF (steady state), 100% of the potential HV of the high-voltage capacitor 16 is applied to thyristor SCR1, and when the voltage HV of the high-voltage capacitor 16 is 2000 [V], the voltage VSCR1 applied to thyristor SCR1 becomes 2000 [V].

[0046] In this way, even if the voltage applied to one thyristor is reduced by connecting thyristors SCR1 and SCR2 in series through the voltage division effect, when both thyristors SCR1 and SCR2 are OFF (steady state), the voltage division effect is not obtained and the entire voltage is applied to the single thyristor SCR1. As a result, thyristors with low voltage resistance cannot be used.

[0047] <2-1> Configuration example 1 6 shows a first example of the configuration of the thyristor-related portion of this embodiment, based on the above considerations. Note that while the configuration of thyristors SCR1 and SCR2 will be described here, the same applies to the configuration of thyristors SCR3 and SCR4.

[0048] In configuration example 1, resistor (voltage dividing resistor) R1 is connected in parallel with thyristor SCR1, and resistor (voltage dividing resistor) R2 is connected in parallel with thyristor SCR2. As a result, even when both thyristors SCR1 and SCR2 are OFF (steady state), the voltage HV of high-voltage capacitor 16 is divided by resistors R1 and R2, preventing a large voltage from being applied only to thyristor SCR1. As a result, thyristors with low voltage resistance can be used. The resistance values ​​of resistors R1 and R2 are, for example, approximately 1 to 2 MΩ.

[0049] Figure 7 is a diagram showing the potential and voltage values ​​when the thyristors SCR1 and SCR2 are turned on and off in the case of using the configuration of Figure 6. Note that Figure 7A is a diagram showing the potential, and Figure 7B is a diagram showing the voltage applied to the thyristors SCR1 and SCR2.

[0050] Note that Figure 7 shows the potential and voltage over a longer period than Figure 5. The region enclosed by a frame in Figure 7, shown as "steady state," is when both thyristors SCR1 and SCR2 are in the OFF state, and corresponds to the period before time t1, which was the problem in Figure 5. Furthermore, times t1 and t2 in Figure 5 exist within the region enclosed by a dotted line, shown as "thyristor ON timing."

[0051] 7B, in configuration example 1, even when both thyristors SCR1 and SCR2 are OFF (steady state), the voltage HV (2000 V) of the high-voltage capacitor 16 is divided by resistors R1 and R2, and the voltage VSCR1 applied to thyristor SCR1 and the voltage VSCR2 applied to thyristor SCR2 are each 1000 V. As a result, thyristors with low voltage resistance can be used.

[0052] By using resistors R1 and R2 with a very large resistance value of 1 to 2 MΩ, the leakage current through resistors R1 and R2 can be made very small. Even if leakage current occurs in the steady state, the current control relay 130 is turned off in the steady state, so this leakage current will not flow to the patient.

[0053] <2-2>Configuration example 2 8 shows a second example of the configuration of the thyristor-related portion of this embodiment. Note that while the configuration of thyristors SCR1 and SCR2 will be described here, the same applies to the configuration of thyristors SCR3 and SCR4.

[0054] In Configuration Example 2, in addition to Configuration Example 1 shown in Fig. 6, an RC circuit in which a resistor R3 and a capacitor C1 are connected in series is connected in parallel to resistor (voltage dividing resistor) R1 (or it may be said that it is parallel to thyristor SCR1), and an RC circuit in which a resistor R4 and a capacitor C2 are connected in series is connected in parallel to resistor (voltage dividing resistor) R2 (or it may be said that it is parallel to thyristor SCR2).

[0055] In addition, in the second configuration example, an inductor 115 is connected between the high-voltage capacitor 16 and the thyristors SCR1 and SCR3, that is, to the input stages of the thyristors SCR1, SCR2, SCR3, and SCR4.

[0056] This makes it possible to prevent a large voltage from being applied to one of the thyristors even if the timing at which thyristor SCR1 turns ON and the timing at which thyristor SCR2 turns ON differ. This will be explained below.

[0057] 9 is a circuit diagram when the thyristor SCR1 is regarded as a variable resistor r1 in configuration example 2. Here, it is assumed that R1=R2=1 [MΩ], R3=R4=20 [Ω], C1=C2=1.5 [μF], and L=50 [μH].

[0058] As the worst case scenario, consider a situation where thyristor SCR1 is completely ON and thyristor SCR2 is completely OFF. In this case, r1 in Figure 9 is approximately 0, and the OFF resistance of thyristor SCR2 and the resistance of R2 are sufficiently large compared to the resistance of R4, so they can be ignored.

[0059] Therefore, the configuration in Figure 9 can be rewritten as shown in Figure 10. The voltage Vp (corresponding to the voltage applied to thyristor SCR1) on the downstream side of inductor 115 (L) in the circuit configuration in Figure 10 changes over time t, as shown in Figure 11. Time t in Figure 11 indicates the elapsed time from when thyristors SCR1 and SCR2 are both OFF and only thyristor SCR1 is turned ON. Here, in the steady state where thyristors SCR1 and SCR2 are both OFF (i.e., when t = 0), the voltage Vp = 1000 [V] as shown in the figure due to the effects of resistors R1 and R2.

[0060] The voltage Vp rises gradually immediately after turning on the thyristor SCR1. This is the effect of providing the inductor 115 (L), resistor R4, and capacitor C2; without these, Vp would instantly reach 2000 V immediately after t = 0.

[0061] In this way, by providing the inductor 115(L), resistor R4, and capacitor C2, even if there is a slight difference between the timing when thyristor SCR1 turns on and the timing when thyristor SCR2 turns on, damage to the thyristors can be prevented. For example, in the example of Figure 11, if a thyristor with a withstand voltage of 1400 [V] is used, damage to the thyristor can be prevented as long as the difference in the timing when they turn on is within 2 [μs].

[0062] In this embodiment, in addition to connecting a series circuit of a resistor and a capacitor in parallel to each of the multiple thyristors SCR1 to SCR4, an inductor 115 is connected between the high-voltage capacitor 16 and the two-phase pulse forming circuit 110, so that when the ON timing of one thyristor differs from the other, the voltage rise applied to one thyristor is slowed down, thereby preventing damage to the thyristor.

[0063] The present disclosure is not limited to this, and the inductor 115 may be omitted. In this case, if the capacitance of the capacitor is increased, the same effect as in the embodiment can be obtained. However, increasing the capacitance of the capacitor leads to an increase in the circuit size compared to when the inductor 115 is provided, so the configuration of the embodiment is more preferable.

[0064] Here, we decided to investigate the time response of the voltage distribution of each element in Figure 10. To do this, we simulated the circuit in Figure 10 using the LCR series circuit in Figure 12, and found the behavior after the switch was turned on using the following differential equation.

number

[0065] Figures 13 and 14 show the time response of the voltage distribution of each element based on the solution of the differential equation. VL is the voltage distribution of the inductor L, VR is the voltage distribution of the resistor R, and VC is the voltage distribution of the capacitor C.

[0066] Fig. 13 shows the time response for the period from 0 to 50 μs, i.e., the period 50 μs after the switch in Fig. 12 is turned on. Fig. 14 shows the time response for the period from 0 to 5 μs, i.e., the period 5 μs after the switch in Fig. 12 is turned on.

[0067] 14, in the period of 0 to 2 μs, inductor L is dominant in terms of voltage sharing. Therefore, providing inductor 115 is very effective in preventing a sudden rise in voltage immediately after the thyristors are turned on at a different timing.

[0068] <3> Configuration for series connection of IGBTs 15 shows an example of the configuration of the IGBT-related portion of this embodiment. Note that although the configuration relating to IGBT1 and IGBT2 will be described here, the configuration relating to IGBT3 and IGBT4 is similar.

[0069] Branch signal lines 151 and 152 branching from a common gate signal line 150 extending from the control unit 120 are connected to the gates of IGBT1 and IGBT2. The common gate signal line 150 is connected to the control unit 120 (FIG. 1). A control signal for controlling the ON / OFF of IGBT1 and IGBT2 is output from the control unit 120 via the common gate signal line 150. This control signal is input to the gates of IGBT1 and IGBT2 via the branch signal lines 151 and 152.

[0070] By providing the common gate signal line 150 in this way, the amount of control in the control unit 120 can be reduced compared to when the control unit 120 outputs control signals separately to IGBT1 and IGBT2. Also, it becomes easier to synchronize the ON / OFF of the two IGBTs, IGBT1 and IGBT2, and the stability of the circuit is increased. Note that the number of IGBTs connected to the common gate signal line 150 is not limited to two, and may be two or more (i.e., multiple).

[0071] In addition, the signal delay amount of the branch signal line 151 connected to the IGBT1 in the upstream stage of IGBT1 and IGBT2 is set to be larger than the signal delay amount of the branch signal line 152 connected to the IGBT2 in the downstream stage of IGBT1 and IGBT2.

[0072] In this embodiment, branch signal line 151 is provided with diode 160 as a delay circuit, which makes the signal delay amount of branch signal line 151 larger than the signal delay amount of branch signal line 152. Note that the signal delay amount of branch signal line 151 may be made larger than the signal delay amount of branch signal line 152 by, for example, making the line length of branch signal line 151 longer than the line length of branch signal line 152.

[0073] In this way, by providing a common gate signal line 150 for IGBT1 and IGBT2 and delaying the gate signal of IGBT1, when an ON control signal is output from the control unit 120, it is possible to reliably turn ON the downstream IGBT2 first, followed by the upstream IGBT1, thereby improving the reliability of the ON operation of IGBTs 1 and 2. As a result, when multiple IGBTs are connected to the common gate signal line 150, the multiple IGBTs can be controlled as if they were a single IGBT.

[0074] Here, the control signal from the control unit 120 is a logic voltage, for example, a voltage of about 5V. On the other hand, IGBTs basically have the same characteristics as FETs, and have the characteristic that they cannot be turned on unless the gate signal is a certain number of volts higher than the output line. For example, if the voltage of the output line is 500V, they cannot be turned on unless a control voltage of about 505V is applied.

[0075] However, in a configuration in which IGBTs 1 and 2 are connected in series, if the IGBT on the ground side is turned on first, it can be turned on with a control voltage of about 5 V. In this embodiment, this operation is achieved by providing a diode 160 as a delay circuit.

[0076] Furthermore, when IGBT1 and IGBT2 are connected in series, as described above in the discussion of the series connection of thyristors, even if an attempt is made to lower the voltage applied to one IGBT by using the voltage division effect of connecting the two IGBTs in series, when both IGBTs are OFF (steady state), the voltage division effect is not obtained and the full voltage is applied to one IGBT. As a result, IGBTs with low voltage resistance cannot be used.

[0077] Considering this, as in the case of series-connected thyristors, as shown in Figure 15, in the series-connected IGBT1 and IGBT2, a resistor R11 is connected in parallel with IGBT1, and a resistor R12 is connected in parallel with IGBT2. This prevents a large voltage from being applied to only one IGBT due to the voltage-dividing effect of the resistors R11 and R12. As a result, IGBTs with low voltage resistance can be used. The resistance values ​​of the resistors R1 and R2 are, for example, about 1 to 2 MΩ.

[0078] Furthermore, by providing the diode 160, it is possible to prevent current from flowing to the common gate signal line 150, as shown in Fig. 16. Specifically, in the configuration of Fig. 16, a high voltage is divided by resistors R11 and R12, so the voltage at point P in the diagram is higher than a general logic voltage (control voltage). By providing the diode 160, it is possible to prevent this high voltage from adversely affecting the logic voltage (control voltage).

[0079] <4> Other embodiments The above-described embodiments are merely examples of specific embodiments of the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be embodied in various forms without departing from the gist or main characteristics thereof.

[0080] 1, the first switching unit 111 is configured by connecting two thyristors SCR1 and SCR2 in series, and the second switching unit 112 is configured by connecting two thyristors SCR3 and SCR3 in series. Also, the third switching unit 113 is configured by connecting two thyristors IGBT3 and IGBT4 in series, and the fourth switching unit 114 is configured by connecting two thyristors IGBT1 and IGBT2 in series. However, the present invention is not limited to this.

[0081] For example, as shown in FIG. 17, all of the first to fourth switching units 111 to 114 may be configured by connecting thyristors in series. In this case, too, the items <2> The configuration described above can be adopted.

[0082] For example, as shown in FIG. 18, all of the first to fourth switching units 111 to 114 may be configured by connecting IGBTs in series. In this case, too, the items <3> The configuration described above can be adopted.

[0083] In the above embodiment, the diode 160 is used as the delay circuit, but a delay circuit other than a diode may also be used.

[0084] <5> summary (1) One embodiment of the defibrillator 100 of the present disclosure is a defibrillator having an H-bridge type biphasic pulse forming circuit 110 connected to the rear stage of a high-voltage capacitor 16, and the biphasic pulse forming circuit 110 includes a first switching unit 111, a second switching unit 112 connected in parallel to the first switching unit 111, a third switching unit 113 connected in series to the rear stage of the first switching unit 111, and a fourth switching unit 114 connected in series to the rear stage of the second switching unit 112. 14, and outputs a biphasic pulse from a first output line L1 connected to a connection midpoint between the first switching unit 111 and the third switching unit 113, and a second output line L2 connected to a connection midpoint between the second switching unit 112 and the fourth switching unit 114, and at least one of the first to fourth switching units 111 to 114 has a plurality of thyristors connected in series, and resistors R1 and R2 connected in parallel to each of the plurality of thyristors.

[0085] As a result, even when both series-connected thyristors SCR1 and SCR2 are OFF (steady state), the voltage HV of the high-voltage capacitor 16 is divided by the resistors R1 and R2, preventing a large voltage from being applied to only one of the thyristors, SCR1. As a result, thyristors with low voltage resistance can be used.

[0086] (2) In one aspect of the defibrillator 100 of the present disclosure, in the configuration of (1), a series circuit of a resistor and a capacitor is connected in parallel to each of the multiple thyristors.

[0087] This makes it possible to suppress a sudden rise in voltage immediately after the thyristors' ON timing shift, even if there is a difference between the timing at which one of the series-connected thyristors, SCR1, turns ON and the timing at which the other, SCR2, turns ON, and to prevent a large voltage from being applied to one of the thyristors, SCR1.

[0088] (3) In one embodiment of the defibrillator 100 of the present disclosure, in the configuration of (2), an inductor 115 is connected between the high-voltage capacitor 16 and the biphasic pulse forming circuit 110.

[0089] This makes it possible to effectively suppress the sudden rise in voltage immediately after the thyristor's ON timing is shifted, even with a small circuit scale.

[0090] (4) In one aspect of the defibrillator 100 of the present disclosure, in the configuration of (1), the first switching unit 111 and the second switching unit 112 each have a configuration in which multiple thyristors are connected in series, and the third switching unit 113 and the fourth switching unit 114 each have a configuration in which multiple IGBTs (Insulated Gate Bipolar Transistors) are connected in series.

[0091] (5) In one aspect of the defibrillator 100 of the present disclosure, in the configuration of (4), a plurality of branch signal lines 151, 152 branched from a common signal line 150 from the control unit 120 are connected to the gates of the plurality of IGBTs 1, 2, and the signal delay amount of the branch signal line 151 connected to the IGBT 1 at the front stage among the plurality of IGBTs 1, 2 is greater than the signal delay amount of the branch signal line 152 connected to the IGBT 2 at the rear stage among the plurality of IGBTs 1, 2.

[0092] This reduces the amount of processing by the control unit 120 compared to when multiple IGBTs 1 and 2 are controlled separately. It also makes it easier to synchronize the ON / OFF of multiple IGBTs 1 and 2, improving circuit stability. Furthermore, it is possible to reliably turn on the IGBTs in the order of downstream IGBT 2 → upstream IGBT 1, improving the reliability of the ON operation when multiple IGBTs 1 and 2 are connected in series.

[0093] (6) In one aspect of the defibrillator 100 of the present disclosure, in the configuration of (5), a delay circuit 160 is provided in the branch signal line 151 connected to the IGBT 1 on the upstream side.

[0094] (7) In one aspect of defibrillator 100 of the present disclosure, in the configuration of (5), resistors R11 and R12 are connected in parallel to the plurality of IGBT1s and IGBT2s, respectively.

[0095] As a result, even when both IGBT1 and IGBT2 connected in series are in the OFF state (steady state), the voltage HV of the high-voltage capacitor 16 is divided by the resistors R11 and R12, preventing a large voltage from being applied to only IGBT1. As a result, IGBT1 and IGBT2 with low withstand voltage performance can be used.

[0096] (8) In one aspect of the defibrillator 100 of the present disclosure, in any of the configurations (1) to (7), the biphasic pulse forming circuit 110 outputs a first-phase pulse when the first and fourth switching units 111, 114 are in the ON state and the second and third switching units 112, 113 are in the OFF state, and outputs a second-phase pulse that is opposite in phase to the first phase when the first and fourth switching units 111, 114 are in the OFF state and the second and third switching units 112, 113 are in the ON state. When outputting a first-phase pulse, the first switching unit 111 is turned ON after the fourth switching unit 114 is turned ON, and when outputting a second-phase pulse, the second switching unit 112 is turned ON after the third switching unit 113 is turned ON.

[0097] (9) One embodiment of the defibrillator 100 of the present disclosure is a defibrillator having an H-bridge type biphasic pulse forming circuit 110 connected to the rear side of the high-voltage capacitor 16. The biphasic pulse forming circuit 110 has a first switching unit 111, a second switching unit 112 connected in parallel to the first switching unit 111, a third switching unit 113 connected in series to the rear side of the first switching unit 111, and a fourth switching unit 114 connected in series to the rear side of the second switching unit 112. The biphasic pulse forming circuit 110 outputs biphasic pulses from a first output line L1 connected to a connection midpoint between the first switching unit 111 and the third switching unit 113 and a second output line L2 connected to a connection midpoint between the second switching unit 112 and the fourth switching unit 114. At least one of the first to fourth switching units 111 to 114 is a multiple IGBT (Insulated Gate Bipolar Transistor). A plurality of branch signal lines 151, 152 branching from a common signal line 150 extending from a control unit 120 are connected to the gates of the plurality of IGBTs 1 and 2, and the signal delay amount of the branch signal line 151 connected to the IGBT 1 at the front stage of the plurality of IGBTs 1 and 2 is greater than the signal delay amount of the branch signal line 152 connected to the IGBT 2 at the rear stage of the plurality of IGBTs 1 and 2.

[0098] This reduces the amount of processing by the control unit 120 compared to when multiple IGBTs 1 and 2 are controlled separately. It also makes it easier to synchronize the ON / OFF of multiple IGBTs 1 and 2, improving circuit stability. Furthermore, it is possible to reliably turn on the IGBTs in the order of downstream IGBT 2 → upstream IGBT 1, improving the reliability of the ON operation when multiple IGBTs 1 and 2 are connected in series.

[0099] (10) In one aspect of the defibrillator 100 of the present disclosure, in the configuration of (9), a delay circuit (diode 160) is provided in the branch signal line 151 connected to the IGBT 1 on the upstream side.

[0100] (11) In one aspect of the defibrillator 100 of the present disclosure, in (9), resistors R11 and R12 are connected in parallel to the plurality of IGBT1s and IGBT2s, respectively.

[0101] As a result, even when the series-connected IGBTs 1 and 2 are all OFF (steady state), the voltage HV of the high-voltage capacitor 16 is divided by the resistors R11 and R12, preventing a large voltage from being applied to only one IGBT 1. As a result, IGBTs 1 and 2 with low withstand voltage performance can be used. [Industrial Applicability]

[0102] The present disclosure is useful as a configuration for the discharge portion of a defibrillator. [Explanation of symbols]

[0103] 16 High-voltage capacitor 100 Defibrillator 110 Biphasic pulse forming circuit 111~114 Switching section 115 Inductor 120 control section 130 Power control relay 140 electrode pads / paddles 150 Common gate signal line 151, 152 branch signal lines 160 Diode SCR1~SCR8 thyristors R1, R2, R3, R4, R11, R12 resistance C1, C2 capacitors

Claims

1. A defibrillator having an H-bridge type biphasic pulse forming circuit connected to the rear side of a high-voltage capacitor, The biphasic pulse forming circuit comprises: a first switching unit; a second switching unit connected in parallel to the first switching unit; a third switching unit connected in series to a downstream side of the first switching unit; a fourth switching unit connected in series to a downstream side of the second switching unit; and outputs a biphasic pulse from a first output line connected to a connection midpoint between the first switching unit and the third switching unit, and a second output line connected to a connection midpoint between the second switching unit and the fourth switching unit, At least one of the first to fourth switching units is A plurality of thyristors are connected in series, and a resistor is connected in parallel to each of the plurality of thyristors. Defibrillator.

2. A series circuit of a resistor and a capacitor is connected in parallel to each of the plurality of thyristors.

10. The defibrillator of claim 1.

3. an inductor connected between the high-voltage capacitor and the biphasic pulse forming circuit; 3. The defibrillator of claim 2.

4. the first switching unit and the second switching unit each have a configuration in which the plurality of thyristors are connected in series, The third switching unit and the fourth switching unit each have a configuration in which a plurality of IGBTs (Insulated Gate Bipolar Transistors) are connected in series.

10. The defibrillator of claim 1.

5. a plurality of branch signal lines branching from a common signal line from a control unit are connected to gates of the plurality of IGBTs; a signal delay amount of a branch signal line connected to an IGBT on a front stage among the plurality of IGBTs is larger than a signal delay amount of a branch signal line connected to an IGBT on a rear stage among the plurality of IGBTs; 5. The defibrillator of claim 4.

6. A delay circuit is provided in the branch signal line connected to the IGBT on the upstream side.

6. The defibrillator of claim 5.

7. A resistor is connected in parallel to each of the plurality of IGBTs.

6. The defibrillator of claim 5.

8. The biphasic pulse forming circuit comprises: outputting a first-phase pulse when the first and fourth switching units are in an ON state and the second and third switching units are in an OFF state; a second-phase pulse that is opposite in phase to the first-phase pulse is output when the first and fourth switching units are in an OFF state and the second and third switching units are in an ON state; When outputting the first-phase pulse, the fourth switching unit is turned on and then the first switching unit is turned on; When the second-phase pulse is output, the third switching unit is turned on and then the second switching unit is turned on.

8. A defibrillator according to any one of claims 1 to 7.

9. A defibrillator having an H-bridge type biphasic pulse forming circuit connected to the rear side of a high-voltage capacitor, The biphasic pulse forming circuit comprises: a first switching unit; a second switching unit connected in parallel to the first switching unit; a third switching unit connected in series to a downstream side of the first switching unit; a fourth switching unit connected in series to a downstream side of the second switching unit; and outputs a biphasic pulse from a first output line connected to a connection midpoint between the first switching unit and the third switching unit, and a second output line connected to a connection midpoint between the second switching unit and the fourth switching unit, At least one of the first to fourth switching units is A plurality of IGBTs (Insulated Gate Bipolar Transistors) are connected in series, a plurality of branch signal lines branching from a common signal line from a control unit are connected to gates of the plurality of IGBTs; a signal delay amount of a branch signal line connected to an IGBT on a front stage among the plurality of IGBTs is larger than a signal delay amount of a branch signal line connected to an IGBT on a rear stage among the plurality of IGBTs; Defibrillator.

10. A delay circuit is provided in the branch signal line connected to the IGBT on the upstream side.

10. The defibrillator of claim 9.

11. A resistor is connected in parallel to each of the plurality of IGBTs.

10. The defibrillator of claim 9.

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