How about PulseLink's Noninvasive Continuous Per-Pulse Arterial Blood Pressure Monitoring System?

Zhejiang PulseLink's Noninvasive Per-Pulse Arterial Blood Pressure Monitoring System is two clip-on near-infrared light sensors (similar to those used to measure oxygen saturation) that detect pulse waves in the posterior auricular artery and dorsal toe artery, and calculate blood pressure from the changes in pulse wave propagation velocity (PWV) and waveform.