New Methodology For Preventing Pressure Ulcers Using Actimetry and Autonomous Nervous System Recording

Abstract

Pressure ulcers constitute an important health problem. They affect lots of people with mobility disorder and they are difficult to detect and prevent because the damage begins on the muscle. This paper proposes a new approach to study pressure ulcers. We aim at developing a methodology to analyse the probability for a patient to develop a pressure ulcer, and that can detect risky situation. The idea is to relate the mobility disorder to autonomic nervous system (ANS) trouble. More precisely, the evaluation of the consequence of the discomfort on the ANS (stress induced by discomfort) can be relevant for the early detection of the pressure ulcer. Mobility is evaluated through movement measurement. This evaluation, at the interface between soft living tissues and any support has to consider the specificity of the human environment. Soft living tissues have non-linear mechanical properties making conventional rigid sensors non suitable for interface parameters measurement. A new actimeter system has been designed in order to study movements of the human body whatever its support while seating. The device is based on elementary active cells. The number of pressure cells can be easily adapted to the application. The spatial resolution is about 4 cm(2). In this paper, we compare activity measurement of a seated subject with his autonomic nervous system activity, recorded by E.motion device. It has been developed in order to record six parameters: skin potential, skin resistance, skin temperature, skin blood rate, instantaneous cardiac frequency and instantaneous respiratory frequency. The design, instrumentation, and first results are presented.

Pressure Ulcers in Pediatric Patients With Spinal Cord Injury

“…60,61,69 Bioimpedance spectrometers were proposed to identify the variations of complex electrical impedances consequent to pathological changes in the skin or underlying deep tissues. 71,72 Instruments that measure the frequency-dependent viscoelastic response of soft tissues are also being tested. The actimeter records the movement of the skin surface in contact with the underlying surface, whereas the recorded autonomic nervous system activity level represents the degree of patient discomfort.…”

Which techniques to improve the early detection and prevention of pressure ulcers?

“…The E.motion device records: skin potential, skin resistance, skin temperature, skin blood rate, instantaneous cardiac frequency and instantaneous respiratory frequency. The complete study is reported in [6]. Actually, actimetry is only related to the Heart Rate Variability (HRV).…”

“…A new actimeter system has been designed in order to study movements of the human body whatever its support while seating [6]. This evaluation, at the interface between soft living tissues and any support has to consider the specificity of the human environment.…”