Assessment of cardiologic systole and diastole duration in exercise stress tests with a transcutaneous accelerometer sensor

A system for non-invasive and automatic assessment of systolic and diastolic duration is presented. The method is based on a accelerometer sensor which was positioned in the mid-sternal precordial region. The acceleration signal, together with an ECG signal, was recorded by a laptop PC and systole and diastole durations were computed for each cardiac beat. The system was tested in 103 patients who performed semi-supine bicycle exercise (71M/32F, age 57±14 years, 17 healthy people 86 patients with cardiovascular diseases). A consistent signal was obtained in 98% patients and systolic/diastolic time ratio as a function of the heart rate was computed. At higher heart rates (for example 100bpm), this ratio was lower in the 17 control subjects (0.74±0.12) than in the patients with systemic hypertension (0.94±0.12), coronary (0.88±0.11), valvular (0.93±0.14) or dilated heart (0.86±0.10) disease.