A compact nanopower low output impedance CMOS operational amplifier for wireless intraocular pressure recordings.

Wireless sensing has shown potential benefits for the continuous-time measurement of physiological data. One such application is the recording of intraocular pressure (IOP) for patients with glaucoma. Ultra-low-power circuits facilitate the use of inductively-coupled power for implantable wireless systems.

Reflectance forehead pulse oximetry: effects of contact pressure during walking.

Steady progress has been made towards the development of a reliable wearable pulse oximeter to aid first responders in remote monitoring and triage operations. This study was undertaken to assess how varying contact pressures affects the photoplethysmographic (PPG) signal, and arterial oxygen saturation (SpO2) and heart rate (HR) measurement errors during motion artifact inducing activity. The study revealed that contact pressures ranging from 8-12 kPa resulted in the largest PPG amplitude for a reflectance sensor attached to the forehead region above the eye, although the signal-to-noise ratio (SNR) did not improve significantly.