Optical Recording and stimulation of an Injectable Wireless Medical Implant

This paper presents a concept design of an injectable implanted biomedical device that is capable of optically stimulating the biological tissue and record the green light emitted from the genetically encoded calcium indicator cells. The implant includes an optical sensor which records the data at 550 nm and micro-LED that stimulate the cells with blue light at 470 nm. Ultrasound link is employed by the external device to power the implant and communicate data at 300 KHz radial resonances frequency. The wireless data transmission link is represented by two off-chip piezoelectric transducers of tube shape and dimensions (OD:3.5, ID:2.5, H:3) mm with 300 KHz radial resonances frequency. Measurement results show that the optical sensor is capable of capturing the incident light at 16 pW/mm2 irradiance, then the recorded illuminance is depicted to be proportional to the value of irradiance.