Purpose

To develop an accurate, noninvasive method for monitoring blood pressure continuously To explore applications in ubiquitous healthcare domain and clinical field, such as operation room and ICU room

Method

Principle - Pulse Arrival Time (PAT) and Intermittent Calibration (IC) - 1. PAT was used to estimate the higher frequency component of blood pressure - 2. IC was used to estimate the lower frequency component of blood pressure - 3. Estimation of blood pressure was obtained by combining these two components Concept of PAT - PAT = interval from QRS peak of ECG to onset of pulse wave Estimation procedure - From upper to lower - 1. Rescaled PAT (RPAT) derived from original PAT - 2. Higher frequency component derived from RPAT - 3. Lower frequency component derived from IC - 4. Estimation result by adding the above two components

Result

Estimations of three typical examples - Child (4, F) - Adult (36, M) - Elder (71, M) Error distribution - 20 persons (14 males and 6 females) - Age range from 4 to 77 (48+/-22) - Totally ca. 42 hours, over 200,000 heartbeats

Further Info

Continuous Estimation of Systolic Blood Pressure Using the Pulse Arrival Time and Intermittent Calibration - Wenxi Chen, Toshio Kobayashi, Seiichi Ichikawa, Yasuo Takeuchi, Tatsuo Togawa - Medical & Biological Engineering & Computing Vol.38, No.5, P569-574, 2000. JAPAN patent: BLOOD PRESSURE MEASURING METHOD - Chen, Wenxi; Kobayashi, Toshio; Togawa, Tatsuo; Takeuchi, Yasuo - App. 1999-279304, 1999/09/30, Open 2001-095766, 2001/04/10, Reg. 3631639, 2004/12/24