Browsing by Subject "Wearable Technology"

Now showing 1 - 3 of 3
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    Fit for Space: Leveraging a Novel Skin Contact Measurement Technique Toward a More Efficient Liquid Cooled Garment
    (2016-08) Compton, Crystal
    Comfort, mobility, and performance are all affected by the fit and contour of a garment to the body. Understanding the body-garment relationship allows for improvement of all of these aspects, and thus the garment and experience for the wearer. With current methods, it is possible to measure the body-garment relationship primarily in static positions, but mobile analysis is time- and equipment-intensive. A more direct garment contour and body contact monitoring procedure would benefit the functional clothing design community. Mobile measurement is especially important for functional garments, as the body-garment relationship changes over time during body movements. Here, we describe a new method developed to measure the body-garment relationship, specifically for mobile scenarios. This method detects body-garment contact using an electrical signal within a circuit formed between the garment and the body. The analog electrical connection (expressed as a varying voltage using a voltage-divider circuit) between the body and a conductive patch is processed and recorded by a microcontroller. In this investigation three main variables were evaluated for their influence on the measurement of body-garment contact: 1) patch materials, 2) applied force, and 3) patch sizes were tested within the body/garment interface. Material results showed that all of the tested materials (with the exception of one material, which contained the sparsest surface area of conductive material) facilitated a voltage response in the presence of body contact that could be viable for detecting contact between body and garment. However, preliminary tests revealed that materials with lower resistivity and more rigid structure facilitated a smoother signal with less noise, which correlated more closely with the input signal. Applied force results showed that the amount of force between the sensor and the body affects the response of the system. All patch sizes with the exception of the smallest size tested (0.3175 cm) were effective in measuring body-garment contact. The smallest diameter possible for the conductive patch is of interest, in an attempt to minimize its effect on the body-garment measuring system. A 0.635 cm diameter conductive hook fastener sensor was subsequently used to implement this method in a pilot evaluation of LCG (Liquid Cooling Garment) fit. A grid of six analog sensors (maximum amount for microcontroller used) was integrated into the right torso region of the LCG for testing. Various movements that would be similar to movements that astronauts would be performing in EVA were used to test body-garment contact. Results show distinct differences in body contact for each sensor during each movement.
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    Manufacturing Cut-And-Sew Garment-Integrated Technologies: An Investigation Of Surface-Mount Fabrication For Electronic Textiles
    (2020-08) Islam Molla, Md. Tahmidul
    The current wearable industry often uses custom made techniques (e.g., craft-based, hobbyists) that utilized proprietary equipment in a laboratory setting with specific applications in mind. While craft construction of textile-integrated electronics is common, these methods are typically not efficient enough for larger-scale production. For larger-scale production, the barriers to textile- and garment-integration have restricted the ability to spatially distribute technology over the body surface, particularly sensing and actuating components that may rely heavily on or be strongly affected by their specific location on the body. Industrial fabrication of e-textiles requires an efficient and scalable process that allows spatial distribution of components with a careful balance of automation and human labor. This research project aims to develop, characterize, and assess a scalable manufacturing method for garment-integrated technologies that preserve user comfort and work within the constraints of typical apparel manufacturing processes while providing required electrical performance and durability needed by the system. We have developed a method for attaching discrete surface-mount components and characterized the method. The method uses an industrial pattern stitching machine to stitch conductive traces onto a fabric surface in a 2D pattern and a reflow technique to integrate electronic components. Several prototypes from small fabric swatches to completed e-textile garments were made and tested to evaluate the durability, efficiency, and effectiveness of the method. We show a durability of 3% joint failure after a 14-hour wear test with no insulation and 0% failure rate after a washability test with insulation for the best manufacturing conditions. To investigate the scalability of the method at a garment scale as compared to manufacture of non-electronic garments, forty pieces each of regular and temperature sensing fire-fighter turnout gear coat liner garments have been produced. This manufacturing case study was used to evaluate the successful functionality of the manufactured garments as well as the impact of integrating electronic technology on labor, equipment, and cost. The study results show that the average manufacturing time to produce a sensor-integrated thermal liner was 3.27 times higher than producing a regular thermal liner garment, given that all the materials, labor, and machines remain constant. The sensor-integrated thermal liner garment cost around 3.44 times more to produce compared to the regular thermal liner garment. However, further analysis showed that by optimizing some of the processes, and using fully functional machines and skilled laborers, the production cost of the same sensor-integrated garment could be cut down by almost 51% and if the production takes place in a developing country where labor cost is much lower than in developed countries, the cost of production could be cut down to as much as 72%. Moreover, it would require more skilled laborers and better training of the laborers to produce e-textile garments compared to regular garments. We show that with strategic design and using existing machines and tools, technologies could be integrated into clothing during the assembly process using existing apparel manufacturing technology without a significant impact on labor, equipment, and cost. Furthermore, results of this case study were used to identify the more abstract challenges including machine optimization, human errors, and process variables involved in transitioning from one-off production to a larger-scale context in a Cut-Make-Trim (CMT) factory setting. The manufacturing method could be potentially used as an alternative for manufacturing e-textiles in mass.
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    Use of Wearable Technology and Social Media to Improve Physical Activity and Dietary Behaviors among College Students: A 12-week Randomized Pilot Study
    (2018-06) Pope, Zachary
    Introduction: College students are at risk for poorer health behaviors. Therefore, this study evaluated the combined effectiveness of the Polar M400 smartwatch and a theoretically-grounded, Facebook-delivered health education intervention at improving college students’ health behaviors/outcomes versus comparison. Intervention use/acceptability and validation of Polar M400 health metric data were also assessed. Methods: Thirty-eight college students (28 female; X̅age=21.5±3.4 years) participated in this two-arm randomized 12-week pilot trial. After screening, participants were randomized into two groups: (a) experimental-received Polar M400 and a twice-weekly Social Cognitive Theory (SCT)- and Self-Determination Theory (SDT)-based, Facebook-delivered health education intervention; and (b) comparison-enrolled only in separate, but content-identical, Facebook group. ActiGraph Link accelerometers and the National Cancer Institute’s ASA24 food recall measured PA and dietary behaviors, respectively. Health-related SCT and SDT psychosocial constructs were measured using psychometrically-validated questionnaires while the YMCA 3-Minute step test and bioelectrical impedance assessed cardiorespiratory fitness and body fat percentage, respectively. Results: Retention rate was 92.1%, with an intent-to-treat analysis performed. Baseline comparisons revealed only one significant difference between groups for whole grain consumption (p=0.03). For PA, a trend toward a significant main effect for time was observed for moderate-to-vigorous PA, F(2, 72)=2.6, p=0.08; partial eta-squared=0.07, with experimental and comparison groups demonstrating 4.2- and 1.6-minute/day increases, respectively, over time. For secondary outcomes, both groups demonstrated non-significantly decreased weight from baseline to 12 weeks (experimental: -0.6 kg; comparison: -0.5 kg). Further, significant main effects for time were observed for self-efficacy, social support, and intrinsic motivation (all p<0.01; partial eta-squared range: 0.18-0.38) as both groups improved over time. Finally, both groups demonstrated consistently decreased daily kcaloric consumption during the intervention. Intervention adherence was high (~86%), with health education tips implemented multiple times weekly. Validation of the Polar M400 versus the ActiGraph Link suggested moderate validity/reliability for steps per day measurements, with poor validity/reliability observed for Polar M400 daily activity time measurements. Discussion: The current study’s observations indicated initial efficacy of an intervention combining a smartwatch and theoretically-grounded, social media-delivered health education intervention on improving college students’ health behaviors/outcomes. Yet, this intervention may not provide greater benefit than comparison. Future studies should build upon noted limitations.