Feasibility evaluation of Smart Stretcher to improve patient safety during transfers

The integration of noninvasive vital sign sensors and wireless sensor networks into intelligent alarm systems has the potential to improve patient safety. We developed a wireless network-based system ("Smart Stretcher"), which was designed to constantly monitor patient vital signs and detect apnea during transfers within a hospital. The system alerts medical staff in case of an emergency through a wireless network.

A small-scale technical feasibility study was conducted to assess the performance of the system in a simulated hospital environment. Smart Stretcher consists of three components: a small air-mat type pressure sensor measuring respiratory rate and detecting apnea, a patient identification system using RFID technology, and an indoor positioning system using a ZigBee wireless network. In the feasibility experiment, two nurses transferred four subjects who stopped breathing for 10 seconds, after which we calculated the accuracy of apnea detections, repeating this at varying speeds and subject positions. We also performed a subjective evaluation of perceptions and expectations of Smart Stretcher by nurses.

The system could detect apnea in all subjects at a rate of over 90%, patient IDs and locations were correctly detected in real time, and the system could alert medical staff. In addition, the results of nurse's evaluations were mostly positive.

The technical feasibility experiment and evaluation of Smart Stretcher suggest that the system could play a key role in monitoring patients during hospital transfers.