Garment-Based Respiration And Pulse Oximetry Sensing Using A Stitched Sensor And Chest Mounted Pulse Oximetry Sensor

Abstract

Garment-based wearable devices have the potential to make on-body sensing of vital signs a more seamless part of everyday life. This research seeks to investigate a wearable chest-mounted stitched strain sensor and pulse oximeter for the purpose of developing a garment-based sensing device. A wearable or garment-based device could be used for long term or long distance monitoring a wearer’s respiratory health when regular access to healthcare is challenging due to distance, such as is the case in many rural communities. However, the effect of fit and sizing of a wearable device is a significant challenge when it comes to the balancing comfort and sensor accuracy needs in a wearable device. A stitched conductive thread sensor and an adapted pulse oximeter probe integrated into a chest-mounted mounted adjustable sensor belt were investigated to understand their performance relative to more typical sensing approaches. Two fit conditions were employed to measure effects on sensor performance and understand the challenges presented by garment-based sensing of respiratory signals. This research found that in general a tighter fit condition improved the performance of the stitched respiration sensor and chest mounted pulse oximeter, however sensor dropout greatly influenced both blood oxygen saturation (SpO₂) and beats-per-minute (BPM) data resulting in suboptimal readings. The stitched sensor was more accurate in measuring breath frequency than the comparison clinical device when fit was not optimized. As a result of this research, it is clear that the fit and sizing of a garment-based sensing device is a crucial factor in developing sensing garments suitable for everyday use.