Design and Analysis of Fully Portable, Battery Powered, Photoacoustic Systems

Open Access
- Author:
- Shirley, Tyler
- Area of Honors:
- Electrical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Sri-Rajasekhar Kothapalli, Thesis Supervisor
Julio Urbina, Thesis Honors Advisor - Keywords:
- Portable
Battery Powered
Photoacoustic
Imaging
Ultrasound
Biomedical Engineering
Electrical Engineering - Abstract:
- In recent years, the demonstration of the feasibility and effectiveness of wireless ultrasonic transducers by researchers and major biomedical imaging companies has demonstrated the great demand for closely related wireless biomedical devices. The extension of this technology into the field of photoacoustics has not yet been demonstrated as no standalone wireless photoacoustic imaging devices have been developed by any research group to the knowledge of the author. Our lab has investigated the feasibility of developing a compact scanning system for use in a wireless wearable photoacoustic tomography system capable of imaging the vascular structure and oxygen saturation of a mouse’s brain. The preliminary testing of our prototype photoacoustic system has demonstrated that photoacoustic sampling can be established using minimal electrical hardware and running purely from a (26,800 mAh) lithium ion battery. In effect, we were able to develop the beginning stages of a purely mobile photoacoustic system with onboard data storage. After filtering and amplification using a VCA2615 variable gain amplifier evaluation board, 20mV amplitude photoacoustic signals were able to be generated with a minimal noise component allowing for photoacoustic distance measurements to be demonstrated and for the FFT data of a single pulse to be generated. With the development of a miniaturized photoacoustic system that can be integrated into a wireless, wearable harness, photoacoustic tomography can then be utilized to study active, moving, untethered samples, thus greatly expanding the application of this emerging technology. Once these last remaining areas of focus have been completed, this will allow for monitoring of the mouse while awake and active. These tests will be a proof of concept for human-based wearable medical devices of similar function. This has widespread implications on improving how neurological, cancerous, and cardiovascular diseases are monitored [1]. Future work will involve further miniaturization of the entire system to enable the electronics to be integrated into a standalone harness. In addition, the implementation of a 5MHz-20MHz bandpass filter will also be investigated as to improve the signal to noise ratio and a translational stage will be added to enable multipoint analysis. Lastly, work needs to begin on creating a system to wirelessly send the photoacoustic data to an offboard computer via WIFI.