Diagnostics and Decision Support for Cardiovascular System

The present chapter proposes a photoplethysmography (PPG) based non-invasive, rapid, inexpensive, automated diagnostic and decision support tool for cardiovascular ailments. An indigenous, cost-effective setup consisting of microcontroller based data acquisition with computerized signal processing and diagnostic software is presented in an entrepreneurial spirit. The PPG signature was obtained using infrared light through the fingertip in reflectance mode. A study on accumulated PPG signatures with 15 volunteers (a pertinent age group ranging from 11–12 years, 21–25 years, 35–40 years and 50–62 years.) was carried out. The fiducial points of PPG and its first- as well as second-degree derivative (SDPPG) waveforms are used to obtain valuable information on untimely arterial stiffness and cardiovascular health in general. The developed indigenous system consists of: (i) PPG waveform acquisition system; (ii) data pre-processing; (iii) PPG beat extraction; (iv) analysis of the extracted PPG waveform to identify fiducial points; (v) estimation of clinical parameters, including photoplethysmographic augmentation index (PPGAI), instantaneous heart rate, variability of heart rate in time domain and point care plots offering information about non-linear HRV. The proposed automated device was developed and implemented on ATLAB Environment.