SYSTEM AND METHOD OF ASSESSMENT OF AROUSAL, PAIN AND STRESS DURING ANESTHESIA AND SEDATION

摘要

A PTT (Pulse Transit Time) monitoring system for measuring arousal and responses to stress or pain during sedation or anesthesia includes ECG electrodes and a PPG (photo plethysmography) probe connected to a computer v ia signal conditioning and digitizing hardware. The ECG and PPG waveforms are continuously analyzed to update and display a current estimate of the subject's PPT from heart to hand. For each cardiac cycle, fiducial points ar e identified to indicate the pulse onset time (via QRS detection in the ECG) a nd pulse arrival time (via the point of steepest ascent in the PPG). Finally, t he current PTT estimate is displayed numerically and the trend of PTT is update d every second. Clinicians may interpret the instantaneous PTT value directly or in context of its recent trend. If there is a rapid decrease in PTT much les s than the predetermined baseline value when the patient should be unconscious and free of stress and pain, then supplemental analgesics are administered t o bring PTT greater than or equal to such baseline value.