Designing Wearable Sensing Platforms for Healthcare in a Residential Environment

Abstract

Wearable technologies are valuable tools that can encourage people to monitor their own well-being and facilitate timely health interventions. In this paper, we present SPW-2; a low-profile versatile wearable sensor that employs two ultra low power accelerometers and an optional gyroscope. Designed for minimum maintenance and a long-term operation outside the laboratory, SPW-2 is able to offer a battery lifetime of multiple months. Measurements on its wireless performance in a real residential environment with thick brick walls, demonstrate that SPW-2 can fully cover a room and -in most cases -the adjacent room, as well.

A Comprehensive Study of Activity Recognition Using Accelerometers

“…However, low power accelerometers consume several orders of magnitude less power than low power gyroscopes. For example, the SPW-2 wearable sensor [48] employs the ADXL362 accelerometer and the LSM6DS0 gyroscope; ADXL362 consumes approximately 8 µW at 50 Hz while LSM6DS0 consumes approximately 2.3 mW at 59.5 Hz.…”

“…Regardless of whether the raw data is transmitted wirelessly to the infrastructure or stored to a local flash memory, energy consumption scales with the amount of produced data. Indeed, different configurations of the acceleration sensor can make the battery lifetime of the wearable sensor last from a few days to few years [48]. Therefore, in cases of long experiments where battery lifetime is a concern, accelerometers should not use higher resolution and sampling frequency than necessary.…”

Increasing Bluetooth Low Energy communication efficiency by presetting protocol parameters

“…In order to evaluate the effect of these results on the energy consumption, we can use a rough estimation by an example device power profile. According to [17], the SPW-2 device has an idle power consumption of 8.6 µ W and approximately 20 mW when advertising at 5 dBm. The spared energy can be computed as a multiplication of a difference between advertising power and idle power (=19.9914 mW) and the spared time during connection initiation.…”

Data fusion for robust indoor localisation in digital health

“…Each tile was assigned coordinates in Euclidean space, relative to the 'tile zero'. The users then wore the updated version of the SPHERE accelerometer sensor [16], as well as a camera. The users performed three unscripted 'free-living' experiments of varying length.…”

“…However, wrist-mounted accelerometer activity recognition is usually inferior to prediction from sensors mounted on different parts of the body [15]. Regardless, the wrist remains the least intrusive and most socially acceptable place to wear a sensor [16].…”