Extracorporeal Shock Wave Lithotripsy (ESWL) is a core device in urology for the treatment of urinary calculi. With its advantages of non-invasiveness, trauma-free nature, low treatment cost, and rapid patient recovery, it has become the preferred clinical treatment for urinary calculi including kidney stones, ureteral stones, and bladder stones. The high-voltage pulse power supply is the core power component of ESWL, providing high-energy, high-amplitude high-voltage pulse output for the electromagnetic coil or piezoelectric crystal of the shock wave generator. It generates shock waves through pulse discharge, which focus to break stones inside the body. The energy level, discharge consistency, pulse repetition frequency, and long-term operational stability of its output pulses directly determine the lithotripsy efficiency, therapeutic effect, damage degree to normal human tissues, and service life of the lithotripter. Current mainstream ESWL devices require the high-voltage pulse power supply to deliver an output voltage continuously adjustable from 10kV to 30kV, single-pulse output energy continuously adjustable from 10J to 200J, pulse discharge consistency better than ±2%, and pulse repetition frequency continuously adjustable from 0.5Hz to 2Hz. Failure to meet these specifications will result in unstable shock wave energy, low lithotripsy efficiency, and even damage to normal tissues such as the patient’s kidneys and ureters due to excessive pulse energy, leading to medical accidents. Traditional high-voltage pulse power supplies for lithotripters adopt a topology of power-frequency boosting + thyristor discharge, which suffers from core pain points including low charging voltage control accuracy, poor pulse discharge consistency, low energy conversion efficiency, short switch lifespan, and poor long-term stability. These drawbacks fail to meet the clinical requirements of precise treatment and efficient lithotripsy for modern lithotripters. Relevant designs must strictly comply with IEC 60601-1 General standard for basic safety and essential performance of medical electrical equipment, GB 9706.4 Medical electrical equipment – Part 2-2: Particular requirements for the basic safety and essential performance of high-frequency surgical equipment, and GB 9706.201 Medical electrical equipment – Part 2: Particular requirements for the basic safety and essential performance of extracorporeal induced lithotripsy equipment. They must also satisfy relevant technical specifications for Class II medical device registration by NMPA. Aiming at the core clinical demands and technical challenges of high-voltage pulse power supplies for ESWL, this methodology forms a full-process general technical framework covering topology architecture design, high-energy output optimization, pulse discharge consistency control, safety protection design, and reliability improvement. It can adapt to the high-voltage power supply demands of various ESWL devices and orthopedic shock wave therapy machines, providing standardized design criteria for the domestic substitution and performance enhancement of domestic lithotripsy and therapy equipment. To address the core design challenges of high-energy output, high discharge consistency, and high reliability in ESWL applications, this methodology adopts the main topology architecture of "high-frequency resonant constant-current charging + high-voltage energy storage capacitor + thyristor discharge switch" combined with full digital closed-loop control. This completely breaks the technical bottlenecks of traditional power-frequency charging topology, such as low charging accuracy, poor consistency, and low efficiency, achieving high-precision constant-current charging of high-voltage energy storage capacitors, high-energy pulse output, and high-consistency discharge control, fully matching the clinical treatment requirements of lithotripters. Five core criteria must be followed in the design. First, series resonant constant-current charging topology is selected for the charging circuit. The core selection logic lies in its inherent constant-current output characteristic, enabling linear constant-current charging of high-voltage energy storage capacitors with high charging voltage control accuracy, fast charging speed, and high conversion efficiency. It also achieves zero-current switching (ZCS) of power switches, featuring extremely low switching loss and low electromagnetic interference, perfectly suitable for the fast charging needs of high-energy high-voltage capacitors. Resonant cavity parameters are optimized via fundamental harmonic analysis, with the designed resonant frequency ranging from 20kHz to 50kHz, ensuring sustained soft-switching operation across the full output voltage range of 10kV~30kV and full load range. This raises the overall charging conversion efficiency to over 95%, far exceeding the 60%~70% efficiency of traditional power-frequency charging topology, significantly reducing equipment heating and energy consumption. Second, optimal design of the high-voltage boosting and rectification unit adopts a high-frequency high-voltage step-up transformer with a low-voltage resonant winding on the primary side and a high-voltage winding on the secondary side. Segmented winding technology and multi-layer insulation structure are used to reduce interlayer voltage and improve insulation performance. Meanwhile, magnetic core selection is optimized by adopting high-frequency low-loss ferrite cores to reduce core loss. The secondary side rectification uses a high-voltage silicon stack full-bridge rectifier circuit, selecting high-voltage silicon stacks with reverse withstand voltage ≥50kV, low leakage current, and fast recovery to ensure the efficiency and stability of high-voltage rectification. Third, optimization of energy storage capacitor selection and configuration. As the core energy storage component for high-energy pulse output, high-voltage energy storage capacitors are selected as oil-immersed pulse capacitors or metallized film pulse capacitors with high energy density, low ESR, and long pulse lifespan. Their rated voltage is ≥40kV, single pulse energy storage can exceed 200J, and pulse lifespan is ≥10⁷ times, meeting the long-term clinical service life requirements of the equipment. Meanwhile, according to treatment needs, the energy storage capacity can be flexibly adjusted through series-parallel combination of capacitors to adapt to different energy output ranges. Fourth, reliability design of the discharge switch unit. As the core component controlling pulse energy output, thyristors with high withstand voltage, large current, and long lifespan are selected as the main discharge switches, with rated reverse withstand voltage ≥50kV, peak on-state current capacity ≥10kA, and pulse lifespan ≥10⁷ times. A damping snubber circuit is designed to suppress voltage spikes and current oscillations during discharge, protecting the thyristor switch and extending its service life. For high-energy output scenarios, a multi-thyristor series topology can be adopted to share voltage stress and improve the withstand voltage level and reliability of the discharge switch. Fifth, full digital closed-loop control architecture. Taking FPGA+ARM as the main control core, it achieves high-precision closed-loop control of charging voltage, precise triggering of pulse discharge, and flexible adjustment of pulse repetition frequency. It also realizes equipment status monitoring, fault protection, treatment parameter setting and storage, adapting to the operational needs of clinical treatment. High-energy output and conversion efficiency optimization are the core of this methodology. Aiming at the demand for high-energy pulse output of lithotripters, this methodology forms general optimization criteria for high-energy output from three dimensions: charging efficiency optimization, discharge circuit design, and energy loss suppression. In terms of charging efficiency optimization, the core design criterion is to achieve efficient and fast charging of high-voltage energy storage capacitors. First, through the soft-switching design of series resonant constant-current charging topology, zero-current turn-on and turn-off of power switches are realized, completely eliminating switching loss caused by hard switching. Meanwhile, resonant cavity parameters are optimized to ensure that the power factor of the resonant circuit is close to 1 across the full charging voltage range, minimizing reactive power loss. Second, the design of high-frequency high-voltage transformers is optimized by adopting layered staggered winding technology to improve primary-secondary coupling coefficient and reduce leakage inductance and AC winding loss. Magnetic cores are made of high-frequency low-loss Mn-Zn ferrite material with specific loss ≤300mW/cm³ at the operating frequency to reduce core loss. Third, the design of high-voltage rectifier circuits is optimized by selecting low-forward-voltage drop, fast-recovery high-voltage silicon stacks to reduce conduction loss and reverse recovery loss in the rectification stage. Meanwhile, the layout of the rectifier circuit is optimized to shorten the length of high-voltage loops and reduce losses caused by parasitic parameters. Through the above optimizations, the overall charging efficiency can reach ≥95%. Compared with traditional power-frequency topology, energy consumption is reduced by more than 40%, equipment heating is greatly reduced, supporting long-term continuous operation to meet the clinical needs of continuous treatment for a large number of patients. In terms of low-loss discharge circuit design, the core design criterion is to maximize the energy utilization rate of energy storage capacitors and efficiently convert electric energy from capacitors into mechanical energy of shock waves. First, low-impedance design of the discharge circuit is optimized by using large-cross-section, low-inductance laminated busbars to connect energy storage capacitors, discharge switches, and shock wave generators, controlling the total parasitic inductance of the discharge circuit within 500nH. This reduces impedance loss and energy loss of the loop, ensures the steepness of the discharge current rising edge, and improves the front pressure of shock waves and lithotripsy efficiency. Second, an impedance matching network for the discharge circuit is designed. According to the impedance characteristics of the electromagnetic coil or piezoelectric crystal of the shock wave generator, corresponding damping resistors and tuning capacitors are matched to achieve impedance matching between the discharge circuit and the load, avoid energy reflection, and maximize energy transmission efficiency. Third, the trigger circuit design of the discharge switch is optimized by adopting a strong trigger pulse to drive the thyristor switch, ensuring full conduction of the thyristor within nanoseconds, reducing conduction loss. Meanwhile, synchronous conduction of multiple series-connected thyristors is guaranteed with synchronization accuracy ≤10ns, avoiding overvoltage damage to individual devices and improving discharge efficiency. In terms of energy loss suppression, the core design criterion is to reduce useless energy loss and improve the effective energy output of a single pulse. First, a pre-charging circuit is designed in the charging loop to avoid energy loss caused by inrush current at the initial stage of charging. Meanwhile, charging cut-off control is designed to immediately disconnect the charging loop when the capacitor voltage reaches the preset value, preventing energy loss and voltage deviation caused by overcharging. Second, a reverse voltage suppression circuit is designed in the discharge loop to avoid damage to energy storage capacitors and switching devices caused by reverse voltage after discharge, while recovering reverse energy to improve energy utilization. Third, the overall thermal design is optimized by adopting an air-cooled heat dissipation structure to provide targeted heat dissipation for heating components such as power switches, high-voltage transformers, and rectifier devices, ensuring that devices operate within the rated temperature range and avoiding increased device loss and performance attenuation caused by temperature rise. Pulse discharge consistency optimization is the core of this methodology to meet clinical precision treatment requirements. Aiming at the strict requirements of lithotripters for pulse energy consistency, this methodology forms a full-process general consistency optimization criterion covering high-precision charging voltage control, precise discharge trigger synchronization, and environmental factor compensation. In terms of high-precision closed-loop control of charging voltage, the core design criterion is to achieve precise control of energy storage capacitor charging voltage, ensuring complete voltage consistency for each charge, which is the basis of pulse energy consistency. First, a full-digital constant-current charging closed-loop control algorithm based on FPGA is adopted. A 24-bit high-precision high-speed ADC collects the charging voltage of energy storage capacitors in real time, monitoring voltage changes at a sampling frequency of 1MHz. When the voltage approaches the preset value, a segmented constant-current charging strategy is adopted to gradually reduce the charging current, avoiding overshoot and ensuring charging cut-off voltage control accuracy better than ±0.5%, far exceeding the ±5% accuracy of traditional power-frequency topology. Second, a grid voltage feedforward compensation algorithm is designed to monitor grid input voltage fluctuations in real time, dynamically adjusting the driving parameters of the charging loop to compensate for charging current changes caused by grid voltage fluctuations, ensuring charging voltage consistency under different grid environments. Third, a multi-stage charging calibration function is designed to perform multi-point calibration across the full voltage range of 10kV~30kV, correcting system errors caused by component parameter deviations and ensuring charging accuracy across the full voltage range. In terms of precise synchronous control of discharge triggering, the core design criterion is to ensure consistent trigger timing and intensity for each discharge, avoiding energy deviation caused by inconsistent conduction characteristics of discharge switches. First, a high-precision constant-temperature crystal oscillator is used as the clock reference with a clock frequency ≥100MHz, achieving discharge trigger pulse time control accuracy ≤10ns and ensuring pulse repetition frequency control accuracy better than ±0.1%, adapting to clinical frequency requirements. Second, a strong trigger synchronous drive circuit is designed to output a stable-amplitude, steep-front strong trigger pulse for each discharge, ensuring fast, complete, and synchronous conduction of thyristor switches each time with conduction delay deviation ≤50ns, avoiding discharge energy deviation caused by inconsistent conduction delays. Third, a real-time discharge status monitoring function is designed. A high-speed ADC collects voltage and current waveforms of each discharge in real time, analyzing peak current, pulse width, and energy release efficiency of the discharge, enabling real-time identification and compensation of abnormal discharges to ensure energy consistency for each discharge. In terms of environmental and aging factor compensation, the core design criterion is to eliminate discharge energy deviation caused by temperature changes and device aging. First, a temperature compensation algorithm is designed to collect the operating temperature of the charging loop, discharge switch, and energy storage capacitor in real time, establish a temperature drift model, and dynamically adjust the preset value of charging voltage and charging parameters. This compensates for device parameter drift caused by temperature changes, ensuring pulse discharge energy consistency better than ±2% within the full operating temperature range of 5℃~40℃. Second, a device aging compensation algorithm is designed. Based on the cumulative discharge times, cumulative operating time, and operating stress of the equipment, circuit parameters are dynamically adjusted to compensate for performance aging of core devices such as thyristor switches, energy storage capacitors, and high-voltage transformers during long-term operation, ensuring discharge energy consistency throughout the equipment lifecycle. Third, a single-pulse energy closed-loop calibration function is designed. According to the voltage and current waveforms of each discharge, the actual output pulse energy is calculated and compared with the preset energy value. Dynamic compensation is performed during the next charge to form energy closed-loop control, ensuring the deviation between actual output energy and preset value ≤±1%. Medical safety compliance and reliability design are core constraints of this methodology. Aiming at the clinical application needs of medical lithotripsy equipment, this methodology forms a complete design framework covering electrical safety, treatment safety interlock, protection functions, and reliability improvement. In terms of electrical safety design, it strictly complies with IEC 60601 series and GB 9706.201 special safety standards for medical lithotripsy equipment, adopting a structural design combining double insulation and reinforced insulation. The isolation withstand voltage level between high-voltage loops and low-voltage control loops is ≥2 times the maximum output voltage. Patient leakage current and equipment leakage current are far below standard limits. Meanwhile, a complete anti-electric shock protection structure is designed. All high-voltage components are installed in a fully sealed metal shielded case with safety interlock switches. When the case is opened, high-voltage input is automatically cut off and energy storage capacitors are discharged to ensure absolute safety for operators. In terms of treatment safety interlock and protection function design, a complete treatment safety interlock mechanism is designed, including treatment bed door interlock, emergency stop button interlock, foot switch interlock, shock wave source in-position interlock, and patient contact interlock. High-voltage discharge can only be triggered when all interlock conditions are met to ensure absolute safety of clinical treatment. Meanwhile, ten-level redundant protection functions are designed, including input over/under-voltage protection, charging over-voltage protection, output over-current protection, short-circuit protection, over-temperature protection, abnormal discharge protection, capacitor over-charging protection, thyristor over-current protection, grid abnormality protection, and treatment timeout protection. All protection functions feature hardware and software dual redundancy design with fault response time<1μs. In case of any fault, the charging loop can be cut off instantaneously, energy storage capacitors are safely discharged, and high-voltage pulse output is prohibited to avoid medical accidents. In terms of reliability and lifespan improvement design, all core components are derated according to industrial and medical grade standards, with voltage stress ≤60% of rated value, current stress ≤50% of rated value, and temperature stress ≤70% of rated value, greatly reducing device failure probability. Meanwhile, selection and circuit design are optimized for core vulnerable components. Core components such as thyristor switches, high-voltage silicon stacks, and energy storage capacitors have a pulse lifespan ≥10⁷ times, ensuring the equipment’s mean time between failures (MTBF) ≥10000 hours to meet the long-term clinical use needs of hospitals. In addition, an automatic discharge and maintenance function for energy storage capacitors is designed. Regular charge-discharge maintenance of capacitors can be performed when the equipment is idle to extend capacitor service life. The equipment has passed all GB/T 18268.1 medical equipment EMC tests, ensuring stable operation in the complex electromagnetic environment of hospitals without interfering with other medical equipment. Aiming at the core clinical demands and technical challenges of high-voltage pulse power supplies for ESWL, this methodology forms a full-process general technical framework from topology architecture design, high-energy output optimization, pulse discharge consistency control to safety compliance design. It completely solves the core pain points of traditional lithotripter high-voltage power supplies, such as low charging accuracy, poor discharge consistency, low efficiency, and short lifespan. It achieves charging efficiency above 95% through series resonant constant-current charging topology, charging voltage control accuracy within ±0.5% and pulse discharge consistency within ±2% through full digital closed-loop control, and meets the compliance requirements of medical lithotripsy equipment through all-dimensional safety design. It fully adapts to the clinical requirements of precise treatment and efficient lithotripsy of modern ESWL devices, and can be widely applied to various urinary lithotripters and orthopedic shock wave therapy machines, providing core technical support for the domestic substitution of domestic medical shock wave therapy equipment.