Ultra-High Frequency Photoacoustic Sensor Design for Early Stage Melanoma Diagnosis

Photoacoustic imaging is an emerging imaging technique with application in early melanoma diagnosis, leveraging a laser pulse depositing a dose of energy into an optical absorber, such as melanin. This promising approach aims at detecting the morphological characteristics of a biological sample at depths that cannot be observed by conventional optical techniques. However, the technological immaturity of the sensor limits the spatial resolution, hence the performances of the system in early-stage melanoma diagnosis. In order to address this issue, this paper examines the scaling potential for Ultra-High Frequency Ultrasound PVDF-based sensors, which operate at (50-100 MHz) frequencies and which require a significant miniaturization as their acoustic performance depends on the ratio between their sizes and signal wavelength. The trade-offs between image quality, sensor channel directivity and system noise are discussed reporting simulation results for different μm sensor sizes on imaging performance.