Battery-operated handheld LED-based photoacoustic imaging system integrated with a commercial wireless ultrasound probe

We present the development of a fully handheld, battery-operated photoacoustic imaging (PAI) system integrating a commercial wireless linear ultrasound probe (Clarius L15 HD3) with a custom nanosecond pulsed LED array. Traditional laser-based PAI systems are often bulky, expensive, and limited to laboratory settings. In contrast, our system leverages compact, safe, and cost-effective light emitting diodes (LEDs) and wireless ultrasound hardware to achieve portability and clinical usability. The optical subsystem comprises a linear array of high-speed infrared LEDs (850 nm), driven by a custom-built Nanosecond Pulsed Current Source (NSPCS) capable of delivering sub-100 ns pulses at ≥ 10 kHz of pulse repetition rate. The entire LED assembly and driver are powered by an external battery module, enabling portable operation. Synchronization is achieved by electronically triggering the NSPCS driver from the Clarius L15 probe, allowing precise temporal alignment between light emission and ultrasound acquisition without external computers or oscilloscopes. The system is optimized for superficial imaging, ideal for applications in vascular, musculoskeletal, or dermatologic diagnostics. The Clarius L15, a high-frequency wireless probe, receives both conventional ultrasound and photoacoustic signals, streaming the data wirelessly to a mobile/tablet device. Preliminary phantom experiments demonstrate high-resolution imaging and sufficient SNR, confirming the feasibility of high-speed handheld PAI. This work marks a significant step toward clinically translatable, point-of-care PAI, combining the safety and portability of LEDs with the ease of use and connectivity of modern wireless ultrasound.