A wireless and batteryless 130mg 300µW 10b implantable blood-pressure-sensing microsystem for real-time genetically engineered mice monitoring

Genetic engineering of mice DNA sequences, together with in vivo real-time blood pressure measurement is crucial for identifying an animal's genetic variation susceptibility to cardiovascular-related diseases. However, there is no adequate solution for long-term in vivo blood pressure monitoring to date. Due to the small size of laboratory mice, a miniature, light-weight, wireless, batteryless, implantable microsystem is highly critical to capture accurate biological signals from an untethered animal in its natural habitat, thus eliminating stress and post-implant trauma-induced information distortion. Furthermore, miniaturization of a packaged system is essential for interfacing with a mouse's arteries, which exhibit a small diameter of only 200εm, and is crucial for achieving a reliable sensor-artery contact for accurate measurement. The small artery renders intra-vascular stent-based blood-pressure-sensing techniques infeasible. Remote RF powering has been widely used for biomedical implants [1,2]. However, the proposed microsystem is implanted in a freely moving laboratory mouse, thus resulting in continuously changing magnetic coupling, which demands adaptive control for RF powering.