biosensors Review Sources of Inaccuracy in Photoplethysmography for Continuous Cardiovascular Monitoring Jesse Fine 1, Kimberly L. Branan 1, Andres J. Rodriguez 2, Tananant Boonya-ananta 2, Ajmal 2, Jessica C. Ramella-Roman 2,3, Michael J. McShane 1,4,5,* and Gerard L. Coté 1,5,* 1 Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA; jfi
[email protected] (J.F.);
[email protected] (K.L.B.) 2 Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA; arodr829@fiu.edu (A.J.R.); tboon007@fiu.edu (T.B.-a.); aajma003@fiu.edu (A.); jramella@fiu.edu (J.C.R.-R.) 3 Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA 4 Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA 5 Center for Remote Health Technologies and Systems, Texas A&M Engineering Experimentation Station, Texas A&M University, College Station, TX 77843, USA * Correspondence:
[email protected] (M.J.M.);
[email protected] (G.L.C.); Tel.: +1-979-845-7941 (M.J.M.); +1-979-458-6082 (G.L.C.) Abstract: Photoplethysmography (PPG) is a low-cost, noninvasive optical technique that uses change in light transmission with changes in blood volume within tissue to provide information for cardiovascular health and fitness. As remote health and wearable medical devices become more prevalent, PPG devices are being developed as part of wearable systems to monitor parameters such as heart rate (HR) that do not require complex analysis of the PPG waveform. However, complex analyses of the PPG waveform yield valuable clinical information, such as: blood pressure, respiratory information, sympathetic nervous system activity, and heart rate variability.