Sensing and documentation of body position during ambulatory ECG monitoring

The ability to monitor body position and physical activity during ambulatory recordings of ECGs can aid in clinical diagnosis in assessing both physiologic changes and motion artifacts. We have developed a device which, through the use of appropriately placed micro-fabricated accelerometers, can simultaneously record body position information along with two channels of ECG. This study validates the functioning of such a device by recording from five healthy subjects and twenty patients who were asked to wear the device for one hour. A predetermined protocol of defined periods of standing, sitting, lying supine, and walking was followed. The recordings show that the assessment of body position and motion are highly reliable (90% accuracy) therefore allowing correlation with ECG signals.