Edwin Gerardus Johannus Maria Bongers

Miniature Wireless Inertial Sensor for Measuring Human Motions

A sensor system for measuring human motions is presented. The system consists of a number of miniature wireless inertial sensors that are attached to limbs of a person, and a PC with a wireless receiver that interprets and presents the measurement data. Each of the sensors measures 3D- acceleration, 3D-magnetization (earth magnetic field) and 3D- angular speed (gyroscopes). The data is transmitted via a proprietary protocol on an 802.15.4 radio. The angular accuracy of the calibrated system was found to be better than 3 degrees. The system is currently being applied in a pilot trial for motor rehabilitation of stroke patients.

Unobtrusive Monitoring of Neonatal Brain Temperature Using a Zero-Heat-Flux Sensor Matrix

The temperature of preterm neonates must be maintained within a narrow window to ensure their survival. Continuously measuring their core temperature provides an optimal means of monitoring their thermoregulation and their response to environmental changes. However, existing methods of measuring core temperature can be very obtrusive, such as rectal probes, or inaccurate/lagging, such as skin temperature sensors and spot-checks using tympanic temperature sensors. This study investigates an unobtrusive method of measuring brain temperature continuously using an embedded zero-heat-flux (ZHF) sensor matrix placed under the head of the neonate. The measured temperature profile is used to segment areas of motion and incorrect positioning, where the neonates head is not above the sensors. We compare our measurements during low motion/stable periods to esophageal temperatures for 12 preterm neonates, measured for an average of 5 h per neonate. The method we propose shows good correlation with the reference temperature for most of the neonates. The unobtrusive embedding of the matrix in the neonates environment poses no harm or disturbance to the care work-flow, while measuring core temperature. To address the effect of motion on the ZHF measurements in the current embodiment, we recommend a more ergonomic embedding ensuring the sensors are continuously placed under the neonates head.