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 57plusmn14 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 100 bpm), this ratio was lower in the 17 control subjects (0.74plusmn0.12) than in the patients with systemic hypertension (0.94plusmn0.12), coronary (0.88plusmn0.11), valvular (0.93plusmn0.14) or dilated heart (0.86plusmn0.10) disease.