Polymer sensor embedded, IOT enabled t-shirt for long-term monitoring of sleep disordered breathing

Respiratory monitoring is essential in sleep studies, sport training, patient monitoring, or health at work, among other applications. This paper presents a comprehensive systematic review of respiration sensing systems. After several systematic searches in scientific repositories, the 198 most relevant papers in this field were analyzed in detail. Different items were examined: sensing technique and sensor, respiration parameter, sensor location and size, general system setup, communication protocol, processing station, energy autonomy and power consumption, sensor validation, processing algorithm, performance evaluation, and analysis software. As a result, several trends and the remaining research challenges of respiration sensors were identified. Long-term evaluations and usability tests should be performed. Researchers designed custom experiments to validate the sensing systems, making it difficult to compare results. Therefore, another challenge is to have a common validation framework to fairly compare sensor performance. The implementation of energy-saving strategies, the incorporation of energy harvesting techniques, the calculation of volume parameters of breathing, or the effective integration of respiration sensors into clothing are other remaining research efforts. Addressing these and other challenges outlined in the paper is a required step to obtain a feasible, robust, affordable, and unobtrusive respiration sensing system.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Sensing Systems for Respiration Monitoring: A Technical Systematic Review

Vanegas

Igual

Plaza

2020

“…Completely noninvasive methods such as video [3][4][5], vibration, or Doppler effects [6,7] are comfortable to users but may not be simple to set up or provide the required continuous accuracy. In our previous work, we have observed that polymer-based conductive rubber or conductive stretchable fabric when used as displacement and vibration sensors could introduce a balanced middle ground between these two approaches [8][9][10][11][12][13]. These 'morphic' sensors are worn tight to the body, but not with any significant compressive force; furthermore, they are unobtrusive and are comfortably worn.…”

mentioning

confidence: 99%

Continuous Vital Monitoring During Sleep and Light Activity Using Carbon-Black Elastomer Sensors

Jayarathna

Breen

2020

Self Cite

The comfortable, continuous monitoring of vital parameters is still a challenge. The long-term measurement of respiration and cardiovascular signals is required to diagnose cardiovascular and respiratory diseases. Similarly, sleep quality assessment and the recovery period following acute treatments require long-term vital parameter datalogging. To address these requirements, we have developed “VitalCore”, a wearable continuous vital parameter monitoring device in the form of a T-shirt targeting the uninterrupted monitoring of respiration, pulse, and actigraphy. VitalCore uses polymer-based stretchable resistive bands as the primary sensor to capture breathing and pulse patterns from chest expansion. The carbon black-impregnated polymer is implemented in a U-shaped configuration and attached to the T-shirt with “interfacing” material along with the accompanying electronics. In this paper, VitalCore is bench tested and compared to gold standard respiration and pulse measurements to verify its functionality and further to assess the quality of data captured during sleep and during light exercise (walking). We show that these polymer-based sensors could identify respiratory peaks with a sensitivity of 99.44%, precision of 96.23%, and false-negative rate of 0.557% during sleep. We also show that this T-shirt configuration allows the wearer to sleep in all sleeping positions with a negligible difference of data quality. The device was also able to capture breathing during gait with 88.9–100% accuracy in respiratory peak detection.

“…Sleep studies are a good example scenario where long-term vital parameter monitoring is paramount. The sleep monitoring system should provide minimum intrusion to sleep [8,9]; however, the t current state-of-the-art Polysomnography (PSG) [10] is time-consuming, expensive, limited to in-clinic and provides minimum comfort. The alternative at-home portable sleep study devices use the same conventional sensors in smaller package.…”

mentioning

confidence: 99%

Characterisation of Morphic Sensors for Body Volume and Shape Applications

Arja

Jayarathna

Naik

et al. 2019

Self Cite

Stretchable conductive materials are originally conceived as radio frequency (RF) and electromagnetic interference (EMI) shielding materials, and, under stretch, they generally function as distributed strain-gauges. These commercially available conductive elastomers have found their space in low power health monitoring systems, for example, to monitor respiratory and cardiac functions. Conductive elastomers do not behave linearly due to material constraints; hence, when used as a sensor, a full characterisation to identify ideal operating ranges are required. In this paper, we studied how the continuous stretch cycles affected the material electrical and physical properties in different embodiment impressed by bodily volume change. We simulated the stretch associated with breathing using a bespoke stress rig to ensure reproducibility of results. The stretch rig is capable of providing constant sinusoidal waves in the physiological ranges of extension and frequency. The material performances is evaluated assessing the total harmonic distortion (THD), signal-to-noise ratio (SNR), correlation coefficient, peak to peak (P-P) amplitude, accuracy, repeatability, hysteresis, delay, and washability. The results showed that, among the three controlled variables, stretch length, stretch frequency and fabric width, the most significant factor to the signal quality is the stretch length. The ideal working region is within 2% of the original length. The material cut in strips of >3 mm show more reliable to handle a variety of stretch parameter without losing its internal characteristics and electrical properties.Sensors 2020, 20, 90 2 of 35 services to achieve a pervasive response [7]. Even with the current state-of-the-art technologies, end sensors remain moderately larger in size, cumbersome to use and unsuitable for long-term monitoring. Sleep studies are a good example scenario where long-term vital parameter monitoring is paramount. The sleep monitoring system should provide minimum intrusion to sleep [8,9]; however, the t current state-of-the-art Polysomnography (PSG) [10] is time-consuming, expensive, limited to in-clinic and provides minimum comfort. The alternative at-home portable sleep study devices use the same conventional sensors in smaller package. A radical change in sensor technologies required to make vital monitoring devices comfortable and "invisible" to the user. The rise of "invisibles" targets making wearable devices built into the commodities people use daily, such as clothes, shoes and jewellery [11]. Usage of the correct type of sensors would enable low-cost implementations that can be embedded in day-to-day clothes that facilitate long-term monitoring [12].Recently, many sensors suitable for tidal monitoring have been presented [13][14][15][16][17]. Electro-resistive sensors based on carbon polymers have shown a great potential for biomedical sensors, and specifically wearable sensors [18], and bio-impedance monitoring [19]. Electro-resistive sensors are made by re-purposing electromagnetic interfer...