Long-term monitoring of HRV and activitiy with a new acquisition system: Preliminary data from a pilotstudy with depressive inpatients

Abstract

Background

Variations of circadian activity profiles and sleep patterns are altered in various neurospsychiatric disorders. In this context, changes in heart rate (HR), -variability (HRV) and related parameters have been reported, too. However, data situation is presently heterogeneous and nonstandard-ized. As long-term evaluation may provide more valuable information, applicability and data us-ability of a new data acquisition system was tested in patients with major depression.

Methods

The course of a depressive episode in inpatients was assessed by standard psychometric in-struments. ECG and motor activity were recorded continuously with a new wearable sensor sys-tem (EP04106001.3) consisting of a textile with three electrodes for 1-lead ECG recordings, and an electronic module (2D-accelerometer, microcontroller, memory, rechargeable batteries, Bluetooth unit) to be attached to the waistband of standard underpants.

Results

ECG signal quality highly depended on physical activity, but sufficient data quality was obtained during sleep. From the accelerometer signal, time in bed and movement time were identifiable. Preliminary data of patients (n=15) versus healthy controls (n=9) showed a reduction of HRV in several time domain parameters, high frequency (HF) power, and daytime activity (24h/day, mean 8 weeks).

Conclusion

This first pilot study demonstrates alterations of physiological parameters potentially relevant for depression, with continuous monitoring of inpatient treatment period. Facing long-term monitoring the device proved to be robust and safe and might provide a psychobiological profile of the clini-cal course of depression, useful for evaluation of disorder and therapy.

Acknowledgement

This work is part of the European research project ‘MyHeart’ (6th framework, IST 507816).