A Novel Approach to Acquire the Arterial Pulse by Finger Plethysmography Using Fiber Bragg Grating Sensor

Finger plethysmography is a well-known technique for the acquisition of arterial pulse waveforms in the field of cardiology. The technique involves the acquisition of the volumetric variation of the finger due to pulsatile flow of blood in ulnar artery, to obtain the arterial pulse waveform of the subject. Conventionally, finger plethysmography is carried out by pulse-oximetry method which evaluates the blood flow using the oxygen saturation levels in blood. Though this method is widely used, the data acquired from this method is not the actual pulse pressure experienced by the arterial walls. Therefore, in the present work, a novel, non-invasive Fiber Bragg Grating based arterial pulse acquisition device employing finger Plethysmographic technique is designed and developed. The developed Fiber Bragg Grating Plethysmographic Pulse Recorder (FBGPPR) can acquire the volumetric variations of the finger on a beat-to-beat basis, which represents the arterial pulse waveform. Further, Pulse Transit Time (PTT) evaluation is also illustrated employing FBGPPR and an electronic stethoscope wherein both the devices are triggered simultaneously. Furthermore, the acquired pulse waveforms are analyzed to obtain the accelerated pulse plethysmograph (APG) which is noteworthy to observe the minute inflections and vital features of the pulse waveform.