BPN926: A Wireless, Implantable, Multicolor Fluorescence Image Sensor for Monitoring Response to Cancer Therapy

We present a mm-sized, ultrasonically powered, lensless CMOS image sensor for wireless fluorescence microscopy. Access to real-time cellular-level information within the tissue can provide new insights for diagnosis and personalized treatment guidance across numerous medical conditions including cancer therapy. In cancer immunotherapy, for instance, where a priori identification of responders is challenging, real-time intratumoral information can aid early assessment of treatment response, identifying activation of the immune system leading to durable responses or rapid recognition of nonresponders. However, current imaging technologies cannot capture multicellular processes deep inside the body in real-time, suffering from large form factors, lack of wireless compatibility, and inadequate resolution needed to monitor the immune response. The proposed device incorporates a 36x40-pixel CMOS image sensor measuring 2.4x4.7 mm2, a sub-mm-sized laser diode, a single piezoceramic, and a storage capacitor. The piezoceramic harvests energy from the acoustic waves at a depth of 2 cm to power up the sensor and transfer 11.5 kbits/frame via ultrasound.