• Single 3 MHz, 10 mm piezoelectric transducer

• A-mode sensing: short pulse transmit, protected receive path, analog front end amplification/filtering, digitization, and MCU processing
• LIPUS therapy: controlled therapeutic burst drive with safety interlocks and continuous monitoring

Diagram

• Power management block with LiPo battery input, protected charging and power path, 3.3 V logic rail, regulated +15 V analog rail, regulated -15 V analog rail, and a higher-voltage pulser rail
• Microcontroller block for mode selection, pulse timing, burst control, safety interlock enforcement, and ADC data handling
• Pulser block for generating short transmit pulses and gated therapy bursts centered at 3 MHz
• T/R protection block that isolates the receive chain during transmit and clamps transducer energy away from the receive path
• Analog front end block including receive protection, variable gain, post-amplification, envelope detection, and band-limiting around 3 MHz
• ADC conditioning block for scaling and filtering the detected signal into the MCU ADC range
• Safety sensor block including at minimum temperature, current, battery or supply status, and audible/visual user alerts under MCU supervision

• Therapy mode is enabled only when no safety fault is active
• Any overtemperature, overcurrent, low battery, or poor contact condition disables the pulser path
• MCU asserts mutually exclusive control of sensing and therapy states
• Receive chain is disabled or protected during transmit events

• Use clear named nets for rails, pulser control, T/R control, ADC interface, sensor alarms, and transducer nodes
• Use an STM32 control block with SWD access and a DS18B20-compatible GPIO plus local clock support
• Keep mixed-signal grounding disciplined, with the analog receive path referenced cleanly and the digital controller return separated in routing intent until the ADC interface region
• Review the finished schematic for complete block interconnection and interlock coverage

• Single-cell LiPo input, charger, and system power path
• 3.3 V, +15 V, -15 V, and pulser high-voltage generation
• STM32 MCU control, SWD programming, I2C battery telemetry, GPIO safety control, and ADC acquisition
• 3 MHz piezo transmit path, T/R protection, receive VGA, envelope detection, and ADC conditioning
• Temperature, current, and battery-status monitoring with LED and buzzer indicators

• Final enclosure mechanics
• Final therapy waveform validation in simulation or bench characterization

• The board shall drive a single 3 MHz ultrasound transducer for transmit and therapy modes.
• The board shall acquire the protected receive signal and present a conditioned detection signal to the MCU ADC.
• The board shall monitor battery, temperature, and pulser current and shall disable therapy on fault.
• The board shall provide LED and buzzer indication for fault or operating status.

• Input power: single-cell LiPo with USB charging and system power-path support
• Key rails: 3.3 V, +15 V, -15 V, and pulser HV rail
• MCU timing target: 3 MHz pulse and timing generation capability
• Receive chain target: 40 dB to 50 dB total gain with bandwidth above 3 MHz
• Critical interfaces: SWD, I2C fuel gauge and charger telemetry, ADC input conditioning, transducer interface, LED and buzzer control

• Wearable use implies compact PCB area, low-profile assembly, and thermally aware placement of charger and power converters away from sensing points
• Thermal safety monitoring is required during therapy operation

• Use production-realistic ICs already present in the design where feasible
• Preserve SWD debug access and named nets for all major rails and controls
• Keep the analog receive path and its grounding strategy distinct from noisy switching and digital timing domains
• Include sufficient local 100 nF decoupling plus bulk rail capacitance at each powered subsystem

• Firmware support for pulse sequencing, ADC acquisition, safety state machine, and user feedback control
• Bench characterization of pulser amplitude, receive gain, and transducer matching

• Placeholder or partially connected blocks can hide unsafe therapy behavior until fully closed out
• Receive path overload during transmit can saturate or damage the analog front end if T/R protection is incomplete
• Mixed-signal ground return errors can degrade the envelope and ADC signal quality

• All charger and rail-generation blocks are present and coherently connected
• MCU, control nets, and safety interfaces are wired for functional firmware control
• Signal flow exists from transducer connector through protection, receive gain, envelope detection, and ADC conditioning to the MCU ADC
• Faults can inhibit the pulser path and drive user-visible alerts

• ERC review for floating pins and single-ended dead nets
• Datasheet cross-check for power, ADC, and analog front-end pin usage
• Bench validation of rail voltages, pulser current sense, over-temperature shutdown, and ADC envelope scaling

• Integrated schematic
• BOM with key ICs and generic passives
• Bring-up and safety verification notes

• Keep test access to major rails and debug signals
• Treat pulser, protection, and receive sections as safety-critical during review

• Captured the integrated wearable ultrasound architecture and subsystem requirements
• Established rail, signal-flow, and safety-interlock intent for schematic completion

• Final device choices for negative rail generation, final pulser stage topology, and final indicator implementation will be resolved during schematic completion