Electric spasm treatment device based on bipolar pulse constant current source

Abstract

The invention relates to an electric spasm treatment device based on a bipolar pulse constant current source. The electric spasm treatment device comprises a medical power supply, a full-bridge inverter and a pulse transformer, wherein the full-bridge inverter is used for converting direct current into bipolar pulse alternating current and outputting a synchronous signal; and a secondary side of the pulse transformer and target tissue impedance form a load loop. A secondary coil of the pulse transformer is sequentially connected with a full-bridge rectifier and a voltage-controlled constant-current source, bipolar pulses are rectified into unipolar pulses through the full-bridge rectifier, the voltage-controlled constant-current source regulates output voltage according to control voltage, and current flowing through the secondary coil and the therapeutic electrode is stably controlled at a preset constant-current value. Therefore, the treatment current applied to the target tissue is kept stable. The device further comprises a detection circuit and a voltage limiting circuit, the treatment voltage is detected in real time and compared with a preset maximum safety voltage threshold value, when the treatment voltage exceeds the limit, a turn-off control signal is output to the full-bridge inverter, driving of a primary coil of the pulse transformer is cut off, and accurate control and safety protection of the treatment current are achieved.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to an electrospasm treatment device based on a bipolar pulsed constant current source. Background Technology

[0002] Electroconvulsive therapy (ECT), also known as electroconvulsive therapy, involves applying brief, precise pulses of electrical current to the patient's brain to trigger widespread epileptiform discharges in the cerebral cortex. These discharges increase the release of neurotransmitters such as serotonin and dopamine, and promote neural plasticity and synaptic remodeling, thereby alleviating psychiatric symptoms. It is a rapid, effective, safe, brief, and non-invasive treatment method.

[0003] Electroconvulsive therapy (ECT) devices apply pulsed currents to a patient's brain via electrodes to alleviate mental symptoms. Existing ECT devices indirectly control the treatment current by controlling the primary current of a pulse transformer, with a control accuracy of 900mA±7.5%, and require periodic calibration, making them inconvenient for clinical use. Summary of the Invention

[0004] To overcome, to some extent, the problems of low control precision, the need for regular calibration, and inconvenience for clinical use in related electroconvulsive therapy devices, this application provides an electroconvulsive therapy device based on a bipolar pulsed constant current source.

[0005] The proposed solution is as follows: An electroconvulsive therapy device based on a bipolar pulsed constant current source, comprising: Medical power supply, used to provide electrical energy to subsequent circuits; A full-bridge inverter connected to the medical power supply is used to convert the DC power output by the medical power supply into bipolar pulse AC power and output a synchronization signal synchronized with the bipolar pulse. A pulse transformer is connected to the output terminal of the full-bridge inverter. The primary coil of the pulse transformer receives the bipolar pulsed AC current, and the secondary coil forms a load circuit with the impedance of the target tissue. The first treatment electrode and the second treatment electrode are disposed in the secondary coil circuit of the pulse transformer. The first treatment electrode is directly electrically connected to one end of the secondary coil of the pulse transformer, and the second treatment electrode is electrically connected to the other end of the secondary coil of the pulse transformer via a full-bridge rectifier, so as to apply the current output by the secondary coil of the pulse transformer to the target tissue impedance connected to the treatment electrode. The full-bridge rectifier has its AC terminals connected to both ends of the secondary coil of the pulse transformer, and is used to rectify the bipolar pulse current output by the secondary coil of the pulse transformer into a unipolar pulse current. A voltage-controlled constant current source is connected in series with the DC terminal of the full-bridge rectifier. The power input terminal of the voltage-controlled constant current source is connected to the synchronization signal output terminal of the full-bridge inverter. The voltage-controlled constant current source, the full-bridge rectifier, the secondary coil winding of the pulse transformer, and the treatment electrode form a closed loop. The voltage-controlled constant current source is configured to adjust its own output voltage according to the control voltage, and stabilize the current flowing through the full-bridge rectifier and the secondary coil winding of the pulse transformer at a preset constant current value, thereby keeping the treatment current applied to the impedance of the target tissue stable. A detection circuit electrically connected to the treatment electrode is used to detect the treatment voltage applied to the impedance of the target tissue and output a detection signal. A voltage limiting circuit connected to the output of the detection circuit is used to compare the detection signal with a preset maximum safe voltage threshold. When the treatment voltage exceeds the maximum safe voltage threshold, a shutdown control signal is output to the full-bridge inverter to cut off the drive of the full-bridge inverter to the primary coil of the pulse transformer.

[0006] Preferably, it further includes: A synchronization circuit connected to the synchronization signal output terminal of the full-bridge inverter, after receiving the synchronization signal, outputs a control signal after a preset delay to turn the voltage-controlled constant current source on or off, thereby outputting the therapeutic current within a predetermined time window.

[0007] Preferably, it further includes: An energy storage capacitor connected to the medical power supply is used to store electrical energy for pulse therapy. The output terminal of the energy storage capacitor is connected to a full-bridge inverter to provide DC power to the subsequent circuits.

[0008] Preferably, the pulse transformer is configured to transform the target tissue impedance to an equivalent impedance that matches the full-bridge inverter and to achieve electrical isolation between the primary and secondary coils to obtain a floating ground output.

[0009] Preferably, the circuit structure of the electroconvulsive therapy device includes: Energy storage capacitor E, field-effect transistors Q1, Q2, Q3, and Q4, gate driver, pulse transformer T, target tissue impedance Z, full-bridge rectifier B, current sampling resistor RS, reference voltage VREF, current-adjusting field-effect transistor CR, error amplifier U1, switching diode D1, switching diode DF, current-limiting resistor R1, current-limiting resistor RF1, current-limiting resistor RF2, isolated NOT gate U2, and detection amplifier U3; Among them, field-effect transistors Q1, Q2, Q3, and Q4, together with the gate driver, form a full-bridge inverter; The current sampling resistor RS, the current limiting resistor R1, the reference voltage VREF, the current regulating field-effect transistor CR, and the error amplifier U1 constitute a voltage-controlled constant current source; The switching diode D1, the current sampling resistor RS, the current limiting resistor R1, and the isolated NOT gate U2 constitute the synchronization circuit; The detection circuit consists of switching diode DF, current-limiting resistor RF1, current-limiting resistor RF2, and detection amplifier U3. The primary coil side of the pulse transformer T has a non-isolated ground reference potential, while the secondary coil side has an isolated ground reference potential. Current is transmitted from the energy storage capacitor E to the target tissue impedance Z through electromagnetic isolation; Signals between non-isolated grounds and isolated grounds are transmitted through isolation circuits; The positive terminal of the energy storage capacitor E is connected to the input terminal of the full-bridge inverter, and the negative terminal is connected to the non-isolated ground. The input terminal of the full-bridge inverter is connected in parallel with the energy storage capacitor E, and the output terminal is connected to the primary coil of the pulse transformer T. The same-name terminal of the secondary coil of the pulse transformer T is connected to the first treatment electrode, and the opposite-name terminal of the secondary coil is connected to the AC input terminal AC1 of the full-bridge rectifier B. The second treatment electrode is connected to the AC input terminal AC2 of the full-bridge rectifier B; The drain of the current-regulating field-effect transistor CR is connected to the positive terminal of the full-bridge rectifier B, the source is connected to the negative terminal of the full-bridge rectifier B through the sampling resistor RS, and the gate is connected to the output terminal of the error amplifier U1. The non-inverting input of the error amplifier U1 is connected to the reference voltage VREF, and the inverting input is connected to the current sampling resistor RS through the current limiting resistor R1. The input of the isolated NOT gate U2 is isolated from the gate driver, and the output is connected to the inverting input of the error amplifier U1 via the switching diode D1. The non-inverting input of the detection amplifier U3 is connected to the isolation ground, the inverting input is connected to the first treatment electrode through the current limiting resistor RF1 and the switching diode DF, and the output is isolated from the gate driver.

[0010] Preferably, the output current pulse when the same-name terminal of the pulse transformer T is positive is defined as a positive polarity pulse, and the output current pulse when the same-name terminal is negative is defined as a negative polarity pulse; When the pulse transformer T outputs a positive pulse, the field-effect transistors Q3 and Q2 are turned on, the same-name terminal of the primary coil of the pulse transformer T is connected to the positive terminal of the energy storage capacitor E, and the opposite-name terminal of the primary coil of the pulse transformer T is connected to the negative terminal of the energy storage capacitor E. A voltage with the same terminal positive is applied to the primary coil of the pulse transformer T. At the same time, a voltage with the same terminal positive is induced on the secondary coil of the pulse transformer T. The induced current flows from the same terminal of the secondary coil of the pulse transformer T through the target tissue impedance Z, enters the full-bridge rectifier B from the AC2 terminal, and then flows from the V+ terminal of the full-bridge rectifier B into the current regulating field-effect transistor CR. After passing through the current sampling resistor RS and the full-bridge rectifier B, it returns to the pulse transformer T, forming a current loop. The primary coil current loop of the pulse transformer T is as follows: from the positive terminal of the energy storage capacitor E to the field-effect transistor Q3 to the pulse transformer T to the field-effect transistor Q2 to the negative terminal of the energy storage capacitor E. The secondary coil current loop of the pulse transformer T is as follows: pulse transformer T to target tissue impedance Z to AC2 terminal of full-bridge rectifier B to V+ terminal of full-bridge rectifier B to current adjustment field-effect transistor CR to current sampling resistor RS to V- terminal of full-bridge rectifier B to AC1 terminal of full-bridge rectifier B to pulse transformer T.

[0011] Preferably, when the pulse transformer T outputs a negative polarity pulse, the field-effect transistors Q1 and Q4 are turned on, the opposite polarity terminal of the primary coil of the pulse transformer T is connected to the positive terminal of the energy storage capacitor E, and the same polarity terminal of the primary coil of the pulse transformer T is connected to the negative terminal of the energy storage capacitor E. A negative voltage is applied to the primary coil of the pulse transformer T at the same terminal, and at the same time, a negative voltage is induced in the secondary coil of the pulse transformer T at the same terminal. The induced current flows out from the opposite terminal of the secondary coil of the pulse transformer T, enters through the AC1 terminal of the full-bridge rectifier B, flows out from the V+ terminal of the full-bridge rectifier B to the current regulating field-effect transistor CR, enters through the V- terminal of the full-bridge rectifier B after passing through the sampling resistor RS, flows out from the AC2 terminal of the full-bridge rectifier B, and returns to the pulse transformer T after passing through the target tissue impedance Z, forming a current loop. The primary coil current loop of the pulse transformer T is as follows: from the positive terminal of the energy storage capacitor E to the field-effect transistor Q1 to the pulse transformer T to the field-effect transistor Q4 to the negative terminal of the energy storage capacitor E. The secondary coil current loop of the pulse transformer T is as follows: from the pulse transformer T to the AC1 terminal of the full-bridge rectifier B to the current adjustment field-effect transistor CR to the current sampling resistor RS to the V- terminal of the full-bridge rectifier B to the AC2 terminal of the full-bridge rectifier B to the target tissue impedance to the pulse transformer T.

[0012] Preferably, the voltage-controlled constant current source controls the positive and negative polarity pulses of the pulse transformer T through a positive phase constant current source circuit and a negative phase constant current source circuit, respectively. Both the positive-phase constant current source circuit and the negative-phase constant current source circuit include a set of current-adjusting field-effect transistors CR, error amplifier U1, switching diode D1, buck resistor and optocoupler; The positive phase constant current source circuit and the negative phase constant current source circuit share the reference voltage VREF and the current sampling resistor RS.

[0013] Preferably, the switching diode DF in the detection circuit is turned on when the pulse transformer T outputs a negative pulse and turned off when the pulse transformer T outputs a positive pulse.

[0014] The technical solution provided in this application may include the following beneficial effects: This application sets up a detection circuit on the treatment electrode side to detect the treatment voltage applied to the target tissue impedance, and then uses a voltage limiting circuit and a voltage-controlled constant current source to form a closed-loop regulation, so that the treatment current flowing through the target tissue impedance is directly monitored and adjusted, thereby achieving precise constant current control of the treatment current.

[0015] The voltage-controlled constant current source stabilizes the current flowing through the full-bridge rectifier and the secondary coil winding of the pulse transformer at a preset constant current value, thereby keeping the therapeutic current applied to the impedance of the target tissue stable.

[0016] By connecting a full-bridge rectifier in series on the secondary coil side of the pulse transformer, and then connecting a unipolar voltage-controlled constant current source in series on the DC side of the full-bridge rectifier, the unipolar constant current source can uniformly control the bipolar therapeutic current after full-bridge rectification. Compared with the scheme of directly setting a complex constant current control circuit on the bipolar pulse side, this structure only requires a single voltage-controlled constant current source module to complete the constant current regulation of the bipolar therapeutic current. The circuit structure is simplified, the number of components is reduced, and the number of failure points is reduced, thereby improving the overall system reliability and the consistency of production assembly, which is beneficial for large-scale production and cost control.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] Figure 1 This is a schematic diagram of the structure of an electrospasm treatment device based on a bipolar pulsed constant current source provided in one embodiment of this application; Figure 2 This is a circuit diagram of an electrospasm treatment device based on a bipolar pulsed constant current source provided in one embodiment of this application; Figure 3 This is a current direction diagram of a pulse transformer outputting a positive polarity pulse in an electroconvulsive therapy device based on a bipolar pulse constant current source, provided in one embodiment of this application; Figure 4This is a current direction diagram of a pulse transformer outputting a negative polarity pulse in an electrospasm treatment device based on a bipolar pulse constant current source, provided in one embodiment of this application. Figure 5 This is a circuit structure diagram of a constant current source circuit provided in one embodiment of this application; Figure 6 This is a circuit structure diagram of a detection circuit provided in one embodiment of this application.

[0020] Reference numerals: First treatment electrode - treatment electrode 1; Second treatment electrode - treatment electrode 2. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] Example 1 Figure 1 This is a schematic diagram of the structure of an electrospasm treatment device based on a bipolar pulsed constant current source, provided in one embodiment of this application. (Refer to...) Figure 1 An electroconvulsive therapy device based on a bipolar pulsed constant current source, comprising: Medical power supply, used to provide electrical energy to subsequent circuits; A full-bridge inverter connected to a medical power supply is used to convert the DC power output from the medical power supply into bipolar pulse AC power and output a synchronization signal synchronized with the bipolar pulse. The pulse transformer is connected to the output terminal of the full-bridge inverter. The primary coil of the pulse transformer receives bipolar pulse AC current, and the secondary coil forms a load circuit with the target tissue impedance. A first treatment electrode and a second treatment electrode are set in the secondary coil circuit of the pulse transformer. The first treatment electrode is directly electrically connected to one end of the secondary coil of the pulse transformer, and the second treatment electrode is electrically connected to the other end of the secondary coil of the pulse transformer through a full-bridge rectifier, so as to apply the current output by the secondary coil of the pulse transformer to the impedance of the target tissue connected to the treatment electrode. A full-bridge rectifier, whose AC terminals are connected to the two ends of the secondary coil of a pulse transformer, is used to rectify the bipolar pulse current output from the secondary coil of the pulse transformer into a unipolar pulse current. A voltage-controlled constant current source is connected in series with the DC terminal of the full-bridge rectifier. The power input terminal of the voltage-controlled constant current source is connected to the synchronous signal output terminal of the full-bridge inverter. The voltage-controlled constant current source, the full-bridge rectifier, the secondary coil winding of the pulse transformer, and the treatment electrode form a closed loop. The voltage-controlled constant current source is configured to adjust its own output voltage according to the control voltage, and stabilize the current flowing through the full-bridge rectifier and the secondary coil winding of the pulse transformer at a preset constant current value, thereby keeping the treatment current applied to the impedance of the target tissue stable. A detection circuit electrically connected to the treatment electrode is used to detect the treatment voltage applied to the impedance of the target tissue and output a detection signal. A voltage limiting circuit connected to the output of the detection circuit compares the detection signal with a preset maximum safe voltage threshold. When the treatment voltage exceeds the maximum safe voltage threshold, a shutdown control signal is output to the full-bridge inverter to cut off the full-bridge inverter's drive to the primary coil of the pulse transformer.

[0023] It should be noted that medical power supplies provide energy to the system while ensuring the electrical safety of the patient.

[0024] The full-bridge inverter converts the DC power from the energy storage capacitor into pulsed AC power, which is then sent to the pulse transformer to achieve bipolar pulses, while simultaneously sending a synchronization signal to the synchronization circuit.

[0025] The pulse transformer is configured to transform the target tissue impedance to an equivalent impedance that matches the full-bridge inverter and to achieve electrical isolation between the primary and secondary coils to obtain a floating ground output.

[0026] The treatment electrode transmits the current output from the pulse transformer to the target tissue, completing the treatment. The first treatment electrode is directly connected to one end of the secondary coil of the pulse transformer. The second treatment electrode is connected to the other end of the secondary coil of the pulse transformer via a full-bridge rectifier. The first treatment electrode... Figures 1-2 The second treatment electrode is represented by treatment electrode 1. Figures 1-2 The treatment electrode 2 is used in the middle.

[0027] The full-bridge rectifier converts the bipolar pulse current output by the pulse transformer into a unipolar pulse current, which is then sent to the voltage-controlled constant current source.

[0028] The voltage-controlled constant current source controls the secondary current of the pulse transformer through a full-bridge rectifier, thereby stabilizing the treatment current.

[0029] The detection circuit detects the treatment voltage applied to the target tissue through electrodes and sends the detection result to the voltage limiting circuit.

[0030] The voltage limiting circuit determines whether the treatment voltage exceeds the maximum value, such as 500V. If it does, the full-bridge inverter is immediately shut down to prevent potential safety hazards to the patient.

[0031] This application sets up a detection circuit on the treatment electrode side to detect the treatment voltage applied to the target tissue impedance, and then uses a voltage limiting circuit and a voltage-controlled constant current source to form a closed-loop regulation, so that the treatment current flowing through the target tissue impedance is directly monitored and adjusted, thereby achieving precise constant current control of the treatment current.

[0032] The voltage-controlled constant current source stabilizes the current flowing through the full-bridge rectifier and the secondary coil winding of the pulse transformer at a preset constant current value, thereby keeping the therapeutic current applied to the impedance of the target tissue stable.

[0033] By connecting a full-bridge rectifier in series on the secondary coil side of the pulse transformer, and then connecting a unipolar voltage-controlled constant current source in series on the DC side of the full-bridge rectifier, the unipolar constant current source can uniformly control the bipolar therapeutic current after full-bridge rectification. Compared with the scheme of directly setting a complex constant current control circuit on the bipolar pulse side, this structure only requires a single voltage-controlled constant current source module to complete the constant current regulation of the bipolar therapeutic current. The circuit structure is simplified, the number of components is reduced, and the number of failure points is reduced, thereby improving the overall system reliability and the consistency of production assembly, which is beneficial for large-scale production and cost control.

[0034] It should be noted that, referring to Figure 1 The electroconvulsive therapy device also includes: The synchronization circuit is connected to the synchronization signal output terminal of the full-bridge inverter. After receiving the synchronization signal, the synchronization circuit outputs a control signal after a preset delay to turn the voltage-controlled constant current source on or off, thereby outputting therapeutic current within a predetermined time window.

[0035] This application receives the synchronization signal output by the full-bridge inverter through a synchronization circuit, and outputs an on-state control signal to the voltage-controlled constant current source after a preset delay, so that the voltage-controlled constant current source can be turned on again within a predetermined time window after the pulse transformer generates a bipolar pulse.

[0036] By utilizing this delayed-on mechanism, the response of the constant current loop can be suppressed during the transient phase of the pulse edge, reducing overshoot and oscillation at the rising edge of the treatment current, improving the rising characteristics and waveform smoothness of the treatment current, thereby reducing the discomfort caused to patients by sudden current changes and improving treatment comfort and safety.

[0037] It should be noted that, referring to Figure 1 The electroconvulsive therapy device also includes: The energy storage capacitor, connected to the medical power supply, is used to store electrical energy for pulse therapy. The output of the energy storage capacitor is connected to a full-bridge inverter to provide DC power to the subsequent circuits.

[0038] The energy storage capacitor stores enough energy to meet the requirements of voltage-controlled constant current.

[0039] Example 2 Reference Figure 2 The circuit structure of the electroconvulsive therapy device includes: Energy storage capacitor E, field-effect transistors Q1, Q2, Q3, and Q4, gate driver, pulse transformer T, target tissue impedance Z, full-bridge rectifier B, current sampling resistor RS, reference voltage VREF, current-adjusting field-effect transistor CR, error amplifier U1, switching diode D1, switching diode DF, current-limiting resistor R1, current-limiting resistor RF1, current-limiting resistor RF2, isolated NOT gate U2, and detection amplifier U3; Among them, field-effect transistors Q1, Q2, Q3, and Q4, together with the gate driver, form a full-bridge inverter; The current sampling resistor RS, the current limiting resistor R1, the reference voltage VREF, the current regulating field-effect transistor CR, and the error amplifier U1 constitute a voltage-controlled constant current source; The switching diode D1, the current sampling resistor RS, the current limiting resistor R1, and the isolated NOT gate U2 constitute the synchronization circuit; The detection circuit consists of switching diode DF, current-limiting resistor RF1, current-limiting resistor RF2, and detection amplifier U3. The primary coil side of the pulse transformer T has a non-isolated ground reference potential, while the secondary coil side has an isolated ground reference potential. Current is transmitted from the energy storage capacitor E to the target tissue impedance Z through electromagnetic isolation; Signals between non-isolated grounds and isolated grounds are transmitted through isolation circuits; The positive terminal of the energy storage capacitor E is connected to the input terminal of the full-bridge inverter, and the negative terminal is connected to the non-isolated ground. The input terminal of the full-bridge inverter is connected in parallel with the energy storage capacitor E, and the output terminal is connected to the primary coil of the pulse transformer T. The same-name terminal of the secondary coil of the pulse transformer T is connected to the first treatment electrode, and the opposite-name terminal of the secondary coil is connected to the AC input terminal AC1 of the full-bridge rectifier B. The second treatment electrode is connected to the AC input terminal AC2 of the full-bridge rectifier B; The drain of the current-regulating field-effect transistor CR is connected to the positive terminal of the full-bridge rectifier B, the source is connected to the negative terminal of the full-bridge rectifier B through the sampling resistor RS, and the gate is connected to the output terminal of the error amplifier U1. The non-inverting input of the error amplifier U1 is connected to the reference voltage VREF, and the inverting input is connected to the current sampling resistor RS through the current limiting resistor R1. The input of the isolated NOT gate U2 is isolated from the gate driver, and the output is connected to the inverting input of the error amplifier U1 via the switching diode D1. The non-inverting input of the detection amplifier U3 is connected to the isolation ground, the inverting input is connected to the first treatment electrode through the current limiting resistor RF1 and the switching diode DF, and the output is isolated from the gate driver.

[0040] Because a full-bridge rectifier B is added between the target tissue impedance Z and the voltage-controlled constant current source, a bipolar current flows through the target tissue impedance Z, while a unipolar current flows through the voltage-controlled constant current source. According to the principle that series currents are equal, the current flowing through the target tissue impedance Z is equal to the current flowing through the voltage-controlled constant current source. Unipolar current control is relatively simple, thus offering higher stability and reliability.

[0041] The output pulse waveform is a bipolar symmetrical square wave, which can be divided into positive and negative polarities. For ease of description, this application defines the output current pulse when the same-name terminal of the pulse transformer T is positive as a positive polarity pulse, and the output current pulse when the same-name terminal is negative as a negative polarity pulse. Reference Figure 3 When the pulse transformer T outputs a positive pulse, the field-effect transistors Q3 and Q2 are turned on, the same-name terminal of the primary coil of the pulse transformer T is connected to the positive terminal of the energy storage capacitor E, and the opposite-name terminal of the primary coil of the pulse transformer T is connected to the negative terminal of the energy storage capacitor E. A voltage with the same terminal positive is applied to the primary coil of the pulse transformer T. At the same time, a voltage with the same terminal positive is induced on the secondary coil of the pulse transformer T. The induced current flows from the same terminal of the secondary coil of the pulse transformer T through the target tissue impedance Z, enters the full-bridge rectifier B from the AC2 terminal, and then flows from the V+ terminal of the full-bridge rectifier B into the current regulating field-effect transistor CR. After passing through the current sampling resistor RS and the full-bridge rectifier B, it returns to the pulse transformer T, forming a current loop. The primary coil current loop of the pulse transformer T is as follows: from the positive terminal of the energy storage capacitor E to the field effect transistor Q3, to the pulse transformer T, to the field effect transistor Q2, to the negative terminal of the energy storage capacitor E, i.e., E(+)→Q3→T→Q2→E(-). The secondary coil current loop of the pulse transformer T is as follows: pulse transformer T to target tissue impedance Z to AC2 terminal of full-bridge rectifier B to V+ terminal of full-bridge rectifier B to current adjustment field-effect transistor CR to current sampling resistor RS to V- terminal of full-bridge rectifier B to AC1 terminal of full-bridge rectifier B to pulse transformer T, that is, T→Z→B(AC2)→B(V+)→CR→RS→B(V-)→B(AC1)→T.

[0042] Reference Figure 4 When the pulse transformer T outputs a negative polarity pulse, the field-effect transistors Q1 and Q4 are turned on, the opposite polarity terminal of the primary coil of the pulse transformer T is connected to the positive terminal of the energy storage capacitor E, and the same polarity terminal of the primary coil of the pulse transformer T is connected to the negative terminal of the energy storage capacitor E. A negative voltage is applied to the primary coil of the pulse transformer T at the same terminal, and at the same time, a negative voltage is induced in the secondary coil of the pulse transformer T at the same terminal. The induced current flows out from the opposite terminal of the secondary coil of the pulse transformer T, enters through the AC1 terminal of the full-bridge rectifier B, flows out from the V+ terminal of the full-bridge rectifier B to the current regulating field-effect transistor CR, enters through the V- terminal of the full-bridge rectifier B after passing through the sampling resistor RS, flows out from the AC2 terminal of the full-bridge rectifier B, and returns to the pulse transformer T after passing through the target tissue impedance Z, forming a current loop. The primary coil current loop of the pulse transformer T is as follows: from the positive terminal of the energy storage capacitor E to the field-effect transistor Q1, to the pulse transformer T, to the field-effect transistor Q4, and then to the negative terminal of the energy storage capacitor E, i.e., E(+)→Q1→T→Q4→E(-). The secondary coil current loop of the pulse transformer T is as follows: from the pulse transformer T to the AC1 terminal of the full-bridge rectifier B to the current adjustment field-effect transistor CR to the current sampling resistor RS to the V- terminal of the full-bridge rectifier B to the AC2 terminal of the full-bridge rectifier B to the target tissue impedance to the pulse transformer T, that is, T→B(AC1)→CR→RS→B(V-)→B(AC2)→Z→T.

[0043] Example 3 It should be noted that the voltage-controlled constant current source controls the positive and negative polarity pulses of the pulse transformer T through the positive phase constant current source circuit and the negative phase constant current source circuit, respectively. Both the positive-phase constant current source circuit and the negative-phase constant current source circuit include a set of current-adjusting field-effect transistors CR, error amplifier U1, switching diode D1, buck resistor and optocoupler; The positive phase constant current source circuit and the negative phase constant current source circuit share the reference voltage VREF and the current sampling resistor RS.

[0044] Because the target tissue impedance Z varies over a wide range (0~500Ω), and the applied current is relatively large (900mA), the voltage-controlled constant current source heats up due to absorbing a large amount of energy at low impedance. To ensure the stability and reliability of the voltage-controlled constant current source, this application employs two constant current source circuits to control the positive and negative polarity pulses of the pulse transformer T, respectively. These two constant current sources share the reference voltage VREF and the current sampling resistor RS, thus avoiding interference between the two constant current sources. In this technical solution, the use of a positive-phase constant current source circuit and a negative-phase constant current source circuit to control the positive and negative polarity pulses of the pulse transformer T respectively improves the power of the constant current and avoids mutual interference between the constant current sources.

[0045] Constant current source circuit such as Figure 5As shown, VREF is a 1.800V±0.1% reference voltage source, RS is a 2.00Ω±0.1% low-temperature drift current sampling resistor, U1 is an error amplifier, CR1 and CR2 are current-adjustable field-effect transistors, and resistors RO1 and RO2 are used to reduce the overshoot of the MOSFET gate voltage. OP1 and OP2 are optocouplers used for delay and isolation, and S(+) and S(-) are positive and negative pulse synchronization signals, respectively. OP1, D1-1, U1A, CR1, VREF, and RS constitute a positive-phase constant current source; OP2, D1-2, U1B, CR2, VREF, and RS constitute a negative-phase constant current source (where D1-1 and D1-2 are the numbers of the switching diode D1 in different constant current source circuits, U1A and U1B are the numbers of the error amplifier U1 in different constant current source circuits, and CR1 and CR2 are the numbers of the current-adjustable field-effect transistor CR in different constant current source circuits).

[0046] When there is no pulse output, both S(+) and S(-) are at low level, the transistors in OP1 and OP2 are cut off, the inverting input terminals of U1A and U1B have a voltage of 3V, and the non-inverting input terminal voltage is 1.800V, so the output voltage is 0V, which turns off CR1 and CR2.

[0047] When a positive pulse is output, S(+) changes from low to high. After a delay of approximately 3μm, OP1 grounds the positive terminal of D1-1. The voltage at the inverting input of U1A equals the voltage across RS. Since CR1 is off, the current is zero, and the voltage across RS is zero. U1A outputs positive saturation and charges the gate capacitance of CR1 through resistor RO1. When the gate potential of CR1 is higher than the turn-on voltage, its drain and source begin to conduct, and the current flowing through RS equals the sum of the gate current and the drain current of CR1. When the voltage across RS equals the reference voltage, U1A switches from saturation to amplification. Deep negative feedback brings the circuit into a steady state, the gate current of CR1 becomes zero, and the drain current of CR1 remains unchanged. The principle is the same when outputting a negative pulse.

[0048] In practice, the reference voltage VREF uses the MCP1501T-18 buffered voltage reference manufactured by Microchip. It has an output voltage of 1.800V, an initial accuracy of 0.1%, and can provide a 20mA pull-in / sink current; its maximum temperature coefficient is 50ppm / °C.

[0049] The current-regulating MOSFET CR uses the IXFX24N100Q3, a Q3 series power MOSFET manufactured by IXYS. This MOSFET features excellent thermal characteristics and robust device durability. Its drain-source rated voltage is 1000V, drain current rated at 24A, gate capacitance at 7200 pF, and power dissipation PD up to 1000W.

[0050] The error amplifier selected is the OPA2994, a newly released dual operational amplifier from TI, capable of driving infinite capacitive loads. This amplifier features a supply voltage of 2.7V to 32V, rail-to-rail input and output, a bandwidth of 24MHz, output current of ±125mA, offset voltage of ±350µV, open-loop gain of 87dB, and an overload recovery time of approximately 130ns. The OPA2994 operational amplifier has a proprietary output compensation structure that senses the output capacitance and adjusts the internal pole and zero structure to achieve acceptable phase margin, allowing the operational amplifier to remain stable under larger capacitive loads.

[0051] Example 4 It should be noted that the switching diode DF in the detection circuit conducts when the pulse transformer T outputs a negative pulse and is cut off when the pulse transformer T outputs a positive pulse.

[0052] The detection circuit is used to measure the voltage across the target tissue impedance Z in order to determine the dynamic impedance and energy delivered to the patient during treatment, and is also used in the voltage limiting circuit.

[0053] Because the rectifier bridge alters the connection between the target tissue impedance Z and the voltage-controlled constant current source, when the pulse transformer T outputs a positive pulse, the target tissue impedance Z is connected to the drain of the current-adjustable field-effect transistor CR; when it outputs a negative pulse, the target tissue impedance Z is connected to the source of the current-adjustable field-effect transistor CR. Compared to the isolation ground, the pulse transformer T outputs a very high common-mode voltage when it outputs a positive pulse, severely affecting the voltage amplifier baseline. To eliminate the influence of the common-mode voltage, this technical solution only detects the voltage amplitude when the pulse transformer T outputs a negative pulse. Because the voltage amplitudes of the positive and negative pulses are essentially equal in each cycle, after detecting the voltage amplitude when the pulse transformer T outputs a negative pulse, the voltage amplitude when the pulse transformer T outputs a positive pulse can be obtained using a peak hold circuit or by calculation.

[0054] The schematic diagram of voltage detection is as follows Figure 6 As shown. Figure 6 In this diagram, V(-) represents the potential generated by the pulse current on tissue Z, which is the potential when a negative pulse is output from the corresponding terminal of the pulse transformer secondary coil. DB is an internal diode of the rectifier bridge. The switching diode DF conducts when the pulse transformer T outputs a negative pulse and is cut off when the pulse transformer T outputs a positive pulse. Resistors RF1 and RF2, along with the detection amplifier U3, constitute an inverting amplifier with a gain A = -(RF2 / RF1). Since the forward voltage drops of DB and DF cancel each other out, the output voltage V3 of U3 is V3 = (RF2 / RF1)V(-).

[0055] The filter capacitor CF is used to eliminate the interference of the pulse edge on the baseline and ensure that V3=0V during a positive pulse.

[0056] The output voltage of the detection amplifier U3 is sent to the analog-to-digital converter (A / D) and the voltage limiting circuit via an isolation amplifier. If this value exceeds the threshold, the voltage limiting circuit immediately shuts down the full-bridge inverter, causing the output voltage to immediately become zero.

[0057] In this technical solution, only the voltage amplitude when the pulse transformer T outputs a negative polarity pulse is detected, and the voltage amplitude when the pulse transformer T outputs a positive polarity pulse is obtained through a peak hold circuit or calculation, thus eliminating the influence of common mode voltage on the baseline.

[0058] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A device for electroconvulsive treatment based on a constant current source with bipolar pulses, characterized in that, The circuit structure of the electroconvulsive therapy device comprises: a medical power supply for providing power to the subsequent circuit; a full-bridge inverter connected to the medical power supply, for converting the direct current output by the medical power supply into bipolar pulse alternating current and outputting a synchronization signal synchronized with the bipolar pulse; a pulse transformer connected to the output end of the full-bridge inverter, wherein the primary coil of the pulse transformer receives the bipolar pulse alternating current, and the secondary coil forms a load loop with the target tissue impedance; a first treatment electrode and a second treatment electrode arranged in the loop of the secondary coil of the pulse transformer, wherein the first treatment electrode is directly electrically connected to one end of the secondary coil of the pulse transformer, and the second treatment electrode is electrically connected to the other end of the secondary coil of the pulse transformer through a full-bridge rectifier, so as to apply the current output by the secondary coil of the pulse transformer to the target tissue impedance connected to the treatment electrode; the full-bridge rectifier, whose alternating current end is connected to the two ends of the secondary coil of the pulse transformer, is used for rectifying the bipolar pulse current output by the secondary coil of the pulse transformer into unipolar pulse current; a voltage-controlled constant current source connected in series to the direct current end of the full-bridge rectifier, wherein the power input end of the voltage-controlled constant current source is connected to the synchronization signal output end of the full-bridge inverter, the voltage-controlled constant current source, the full-bridge rectifier, the secondary coil winding of the pulse transformer and the treatment electrode form a closed loop, and the voltage-controlled constant current source is configured to adjust the output voltage thereof according to the control voltage, so as to stabilize the current flowing through the full-bridge rectifier and the secondary coil winding of the pulse transformer at a preset constant current value, thereby keeping the treatment current applied to the target tissue impedance stable; a detection circuit electrically connected to the treatment electrode, for detecting the treatment voltage applied to the target tissue impedance and outputting a detection signal; a voltage limiting circuit connected to the output end of the detection circuit, for comparing the detection signal with a preset maximum safe voltage threshold, and outputting an off control signal to the full-bridge inverter when the treatment voltage exceeds the maximum safe voltage threshold, so as to cut off the driving of the primary coil of the pulse transformer by the full-bridge inverter.

2. The electroconvulsive therapy device of claim 1, wherein, Further comprising: a synchronization circuit connected to the synchronization signal output end of the full-bridge inverter, wherein the synchronization circuit outputs a control signal to turn on or off the voltage-controlled constant current source after a preset time delay after receiving the synchronization signal, so as to output the treatment current within a predetermined time window.

3. The electroconvulsive therapy device of claim 2, wherein, Further comprising: an energy storage capacitor connected to the medical power supply, for storing the electric energy used for pulse treatment, wherein the output end of the energy storage capacitor is connected to the full-bridge inverter, for providing direct current power to the subsequent circuit.

4. The electroconvulsive therapy device of claim 1, wherein, The pulse transformer is configured to transform the target tissue impedance into an equivalent impedance matched with the full-bridge inverter, and realize electrical isolation between the primary coil and the secondary coil, so as to obtain a floating ground output.

5. The electroconvulsive therapy device of claim 4, wherein, The circuit structure of the electroconvulsive therapy device comprises: Energy storage capacitor E, field effect tube Q1, field effect tube Q2, field effect tube Q3, field effect tube Q4, gate driver, pulse transformer T, target tissue impedance Z, full-bridge rectifier B, current sampling resistor RS, reference voltage VREF, current regulating field effect tube CR, error amplifier U1, switching diode D1, switching diode DF, current limiting resistor R1, current limiting resistor RF1, current limiting resistor RF2, isolation NOT gate U2 and detection amplifier U3; Wherein, field effect tube Q1, field effect tube Q2, field effect tube Q3, field effect tube Q4 and gate driver form a full-bridge inverter; Current sampling resistor RS, current limiting resistor R1, reference voltage VREF, current regulating field effect tube CR and error amplifier U1 constitute a voltage-controlled constant current source; Switching diode D1, current sampling resistor RS, current limiting resistor R1 and isolation NOT gate U2 constitute a synchronization circuit; Switching diode DF, current limiting resistor RF1, current limiting resistor RF2 and detection amplifier U3 constitute a detection circuit; The reference potential of the primary coil side of pulse transformer T is non-isolated ground, and the reference potential of the secondary coil side is isolated ground; The current is transmitted through electromagnetic isolation from the energy storage capacitor E to the target tissue impedance Z; The signal between the non-isolated ground and the isolated ground is transmitted through the isolation circuit; The positive electrode of the energy storage capacitor E is connected to the input end of the full-bridge inverter, and the negative electrode is connected to the non-isolated ground; The input end of the full-bridge inverter is connected in parallel with the energy storage capacitor E, and the output end is connected to the primary coil of the pulse transformer T; The same name end of the secondary coil of the pulse transformer T is connected to the first treatment electrode, and the different name end is connected to the AC input end AC1 of the full-bridge rectifier B; The second treatment electrode is connected to the AC input end AC2 of the full-bridge rectifier B; The drain of the current regulating field effect tube CR is connected to the positive end of the full-bridge rectifier B, the source is connected to the negative end of the full-bridge rectifier B through the sampling resistor RS, and the gate is connected to the output end of the error amplifier U1; The non-inverting input end of the error amplifier U1 is connected to the reference voltage VREF, and the inverting input end is connected to the current sampling resistor RS through the current limiting resistor R1; The input end of the isolation NOT gate U2 is connected to the gate driver in isolation, and the output end is connected to the inverting input end of the error amplifier U1 through the switching diode D1; The non-inverting input end of the detection amplifier U3 is connected to the isolated ground, the inverting input end is connected to the first treatment electrode through the current limiting resistor RF1 and the switching diode DF, and the output end is connected to the gate driver in isolation.

6. The electroconvulsive therapy device of claim 5, wherein, When the same name end of the pulse transformer T is positive, the output current pulse is defined as a positive polarity pulse, and when the same name end is negative, the output current pulse is defined as a negative polarity pulse; When the pulse transformer T outputs a positive polarity pulse, the field effect tube Q3 and the field effect tube Q2 are turned on, the same name end of the primary coil of the pulse transformer T is connected to the positive electrode of the energy storage capacitor E, and the different name end of the primary coil of the pulse transformer T is connected to the negative electrode of the energy storage capacitor E. The same name end of the primary coil of the pulse transformer T is applied with positive voltage, and the same name end of the secondary coil of the pulse transformer T is induced with positive voltage, the induced current flows out from the opposite name end of the secondary coil of the pulse transformer T, enters through the AC1 end of the full-bridge rectifier B, flows out from the V+ end of the full-bridge rectifier B to the current regulating field effect transistor CR, enters from the V- end of the full-bridge rectifier B after passing through the sampling resistor RS, flows out from the AC2 end of the full-bridge rectifier B, returns to the pulse transformer T after passing through the target tissue impedance Z, and forms a current loop; The current loop of the primary coil of the pulse transformer T is: the positive pole of the energy storage capacitor E to the field effect transistor Q3 to the pulse transformer T to the field effect transistor Q2 to the negative pole of the energy storage capacitor E; The current loop of the secondary coil of the pulse transformer T is: the pulse transformer T to the target tissue impedance Z to the AC2 end of the full-bridge rectifier B to the V+ end of the full-bridge rectifier B to the current regulating field effect transistor CR to the current sampling resistor RS to the V- end of the full-bridge rectifier B to the AC1 end of the full-bridge rectifier B to the pulse transformer T.

7. The electroconvulsive therapy device of claim 6, wherein, When the pulse transformer T outputs negative polarity pulse, the field effect transistor Q1 and the field effect transistor Q4 are turned on, the opposite name end of the primary coil of the pulse transformer T is connected with the positive pole of the energy storage capacitor E, and the same name end of the primary coil of the pulse transformer T is connected with the negative pole of the energy storage capacitor E; The same name end of the primary coil of the pulse transformer T is applied with negative voltage, and the same name end of the secondary coil of the pulse transformer T is induced with negative voltage, the induced current flows out from the opposite name end of the secondary coil of the pulse transformer T, enters through the AC1 end of the full-bridge rectifier B, flows out from the V+ end of the full-bridge rectifier B to the current regulating field effect transistor CR, enters from the V- end of the full-bridge rectifier B after passing through the sampling resistor RS, flows out from the AC2 end of the full-bridge rectifier B, returns to the pulse transformer T after passing through the target tissue impedance Z, and forms a current loop; The current loop of the primary coil of the pulse transformer T is: the positive pole of the energy storage capacitor E to the field effect transistor Q1 to the pulse transformer T to the field effect transistor Q4 to the negative pole of the energy storage capacitor E; The current loop of the secondary coil of the pulse transformer T is: the pulse transformer T to the AC1 end of the full-bridge rectifier B to the current regulating field effect transistor CR to the current sampling resistor RS to the V- end of the full-bridge rectifier B to the AC2 end of the full-bridge rectifier B to the target tissue impedance to the pulse transformer T.

8. The electroconvulsive therapy device of claim 7, wherein, The voltage-controlled constant current source controls the positive polarity pulse and the negative polarity pulse of the pulse transformer T through the positive phase constant current source circuit and the negative phase constant current source circuit respectively; The positive phase constant current source circuit and the negative phase constant current source circuit both include a group of current regulating field effect transistors CR, error amplifiers U1, switching diodes D1, kick-down resistors and photoelectric couplers; The positive phase constant current source circuit and the negative phase constant current source circuit share a reference voltage VREF and a current sampling resistor RS.

9. The electroconvulsive therapy device of claim 7, wherein, The switching diode DF in the detection circuit is turned on when the pulse transformer T outputs negative polarity pulse, and is turned off when the pulse transformer T outputs positive polarity pulse.

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