Active Body Pressure Relief System with Time-of-Flight Optical Pressure Sensors for Pressure Ulcer Prevention

Abstract

A body pressure relief system was newly developed with optical pressure sensors for pressure ulcer prevention. Unlike a conventional alternating pressure air mattress (APAM), this system automatically regulates air flow into a body supporting mattress with adaptive inflation (or deflation) duration in response to the pressure level in order to reduce skin stress due to prolonged high pressures. The system continuously quantifies the body pressure distribution using time-of-flight (ToF) optical sensors. The proposed pressure sensor, a ToF optical sensor in the air-filled cell, measures changes in surface height of mattress when pressed under body weight, thereby indirectly indicating the interface pressure. Non-contact measurement of optical sensor usually improves the durability and repeatability of the system. The pressure sensor was successfully identified the 4 different-predefined postures, and quantitatively measured the body pressure distribution of them. Duty cycle of switches in solenoid valves was adjusted to 0–50% for pressure relief, which shows that the interface pressure was lower than 32 mmHg for pressure ulcer prevention.

Battery-free, wireless soft sensors for continuous multi-site measurements of pressure and temperature from patients at risk for pressure injuries

“…Technologies for continuous measurements of local pressures and temperatures at skin interfaces may provide the basis for an improved, quantitative approach for assessing risk and alerting for the need for preventive action. Previously reported approaches use mattress 15 , 16 —and textile 17 —integrated pressure sensors. Such technologies do not, however, allow for accurate tracking of ulcer-related variables, including pressure 18 , skin temperature 19 , relative humidity (RH) 20 and skin blood flow 21 , 22 on body locations of interest through the natural course of postural changes.…”

Mechanical characteristic and analytical model of novel air spring for ergonomic mattress

“…Above analysis is mainly about passively adjustment of air mattresses, and the active depressurization mattress is much more significant. For example, an active depressurization air mattress quantitatively measured body pressure distribution of human-mattress interface and successfully adjusted firmness of mattress by means of Time-of-Flight optical pressure sensors, providing a relatively ideal body pressure distribution [16], however, spinal alignment was still not taken into consideration. Verhaert [17,18], had studied spinal alignment in lying position further, including identifying spinal morphology by indentation on mattress surface and adjusting it by alternating stiffness of a specially designed mattress, which is an important step towards regulating spinal alignment.…”

Medical Robotic Bed to Prevent Pressure Sores

“…This bed utilizes body pressure distribution information, but it is impractical because it requires a large number of actuators for bed operation [14]. An air mattress integrated with a pneumatic pump was developed to estimate body pressure by measuring mattress deformation [15]. Misaki et al proposed an anti-bedsore mattress consisting of multiple air cells and a capacitive pressure sensor.…”