Development of a Compact, Cost-Effective Photoacoustic Spectral Response Measurement System for Biomedical Applications

Photoacoustic spectral response (PASR) technique is a pump-probe technique that provides acoustic spectral information of any biological tissue. This extracted information acts as a signature of the biological tissue. The experimental setups can be bulky, expensive, and involve complex operation due to the requirement of costly
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-switched lasers, complex optics, and limited wavelength. On the other side, setup requires high-frequency signal conditioning, a high-speed oscilloscope, and a computing device to process, analyze, and monitor the acquired signal. This article presents a compact, cost-effective measurement instrument to measure and display the time-domain and frequency spectral information for biomedical applications. The developed electronic hardware is used to perform real-time signal conditioning; subsequently, conditioned photoacoustic (PA) data were acquired with a speed of 30 MSPS, and the results were sent to a monitor to display. Developed hardware contains a high-frequency preamplifier, low-pass filter, electrically isolated trigger circuit, and a 12-bit high-speed analog-to-digital converter to generate digital data, which is further analyzed by a high-speed microcontroller. After calibration of the proposed experimental setup, the developed PA tool is applied to distinguishing lung and liver tissues, and the statistical results corroborate the consistency of the proposed PA-based data acquisition system.