title: Feasibility study for the non-invasive blood pressure estimation based on ppg morphology: normotensive subject study.
abstract: BACKGROUND
  Blood pressure is a critical bio-signal and its importance has been increased with the aged society and the growth of cardiovascular disease population. However, most of hypertensive patients have been suffered the inconvenience in monitoring blood pressure in daily life because the measurement of the blood pressure depends on the cuff-based technique. Nowadays there are many trials to measure blood pressure without cuff, especially, photoplethysmography (PPG) based research is carried out in various ways.
  
  
  METHODS
  Our research is designed to hypothesis the relationship between vessel wall movement and pressure-flow relationship of PPG and to validate its appropriateness by experimental methods. PPG waveform is simplified by approximate model, and then it is analyzed as the velocity and the acceleration of blood flow using the derivatives of PPG. Finally, we develop pressure index (PI) as an estimation factor of blood pressure by combining of statistically significant segments of photoplethysmographic waveform.
  
  
  RESULTS
  Twenty-five subjects were participated in the experiment. As a result of simulation, correlation coefficients between developed PI and blood pressure were represented with R = 0.818, R = 0.827 and R = 0.615 in systolic blood pressure, pulse pressure and mean arterial pressure, respectively, and both of result showed the meaningful statistically significance (P < 0.05).
  
  
  CONCLUSIONS
  Current study can estimate only the relative variation of blood pressure but could not find the absolute pressure value. Moreover, proposed index has the limitation of diastolic pressure tracing. However, the result shows that the proposed PI is statistically significantly correlated with blood pressures, and it suggests that the proposed PI as a promising additional parameter for the cuff less blood pressure monitoring.
authors.affiliation: Healthcare Solution Laboratory, Department of Biomedical Engineering, Chonnam National University, 502, 3rd Eng. Bldg., 50 Daehak-ro, Yeosu, South Korea.
authors.forename: Hangsik
authors.initials: H
authors.lastname: Shin
authors.affiliation: Department of Medical IT Engineering, College of Medical Science, Soonchunhyang University, 22, Soonchunhyang-ro, Eumnae-ri, Sinchang-myeon, Asan-si, Chungcheongnam-do, Republic of Korea. sedongmin@sch.ac.kr.
authors.forename: Se Dong
authors.initials: SD
authors.lastname: Min
mesh_terms: D000328:Adult; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D017156:Photoplethysmography; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: Derivative photoplethysmography; Photoplethysmography (PPG); Pulse pressure; Systolic blood pressure; Vessel wall movement