Lucy E. Dunne

Initial development and testing of a novel foam-based pressure sensor for wearable sensing

BackgroundThis paper provides an overview of initial research conducted in the development of pressure-sensitive foam and its application in wearable sensing. The foam sensor is composed of polypyrrole-coated polyurethane foam, which exhibits a piezo-resistive reaction when exposed to electrical current. The use of this polymer-coated foam is attractive for wearable sensing due to the sensors retention of desirable mechanical properties similar to those exhibited by textile structures.MethodsThe development of the foam sensor is described, as well as the development of a prototype sensing garment with sensors in several areas on the torso to measure breathing, shoulder movement, neck movement, and scapula pressure. Sensor properties were characterized, and data from pilot tests was examined visually.ResultsThe foam exhibits a positive linear conductance response to increased pressure. Torso tests show that it responds in a predictable and measurable manner to breathing, shoulder movement, neck movement, and scapula pressure.ConclusionThe polypyrrole foam shows considerable promise as a sensor for medical, wearable, and ubiquitous computing applications. Further investigation of the foams consistency of response, durability over time, and specificity of response is necessary.

A study of automated custom fit: Readiness of the Technology for the apparel industry

Sophisticated new technologies are available to the apparel industry to create automated custom-fitted clothing; research and development of necessary data and proceduresfor implementing these programs must be within reach of apparel companies to successfully implement custom.fit. This study explores issues in setting up a custom apparel patternmaking process using 3D body scanning and software designed to automate patternmaking. Questions related to measurement reliability and validity, data and knowledge needed to create and test required system variables, andfit preference issues were addressed in this study. A system for generating custom-fitted outerwearjackets was developedfor an industry collaborator, Log House Designs, and tested on ten participants. The.fit of the prototype custom jackets was compared to thefit of a set of ready-to-wearjackets. Seven of the ten participants preferred thefit of the prototype custom jacket; the remaining three were equally satisfied with both jackets.

Design and Evaluation of a Wearable Optical Sensor for Monitoring Seated Spinal Posture

This work describes the development and evaluation of a wearable plastic optical fiber (POF) sensor for monitoring seated spinal posture. A garment-integrated POF sensor was developed and tested on nine healthy subjects, and its performance compared to data taken simultaneously from a marker-based motion capture system. Sensor performance correlated strongly with motion-capture data with an average r of 0.913. Results show that the wearable sensor provides enough accuracy of measurement to reliably monitor seated spinal posture.

A shoulder pad insert vibrotactile display

Touch is the most intimate and inherently private humansense and provides the potential for discrete, low socialweight human computer interaction. This paper presentsinitial research findings on issues of integrating avibrotatcitle display and support electronics into a standardclothing insert, the shoulder pad. Research on constructionmethods is presented along with a discussion of the meritsand drawbacks of each technique. User study data forresponse to tactile display stimuli, collected with a varyingnumber of stimulators, is then presented with initialconclusions as to the type and format of data suitable forshoulder based tactile arrays.

Wearable Monitoring of Seated Spinal Posture

This work describes the evaluation of a wearable plastic optical fiber (POF) sensor for monitoring seated spinal posture, as compared to a conventional expert visual analysis, and the development of a field-deployable posture monitoring system. A garment-integrated POF sensor was developed and tested on nine healthy subjects. Data from the wearable sensor were compared to data taken simultaneously from a marker-based motion capture system, for accuracy and reliability. Peak analysis of the resulting data showed a mean time error of 0.53 plusmn 0.8 s, and a mean value error of 0.64 plusmn 3.1 deg, which represents 14.5% of the average range of motion. Expert determination of transitional (good to bad) posture showed a variation of 20.9% of range of motion. These results indicate that the wearable sensor approximates the accuracy of expert visual analysis, and provides sufficient accuracy of measurement to reliably monitor seated spinal posture.

Psychophysical elements of wearability

Wearable technology presents a wealth of new HCI issues. In particular, this paper addresses the impact of the physical interaction between the users body and the devices physical form on the users mental representation of self and cognitive abilities, a blend of HCI and ergonomics that is unique to wearable computing. We explore the human sensory mechanisms that facilitate perception of worn objects and the elements of sensation that influence the comfort of worn objects, and discuss the psychological elements that may cause worn objects to be forgotten or detected, wearable or not. We discuss the implications of un-wearability on attention and cognitive capability.

Smart Clothing in Practice: Key Design Barriers to Commercialization

Abstract For more than forty years, the promise of electronic clothing has excited designers and consumers alike. The last ten years have seen a dramatic increase in academic and industry research, but few developments have made it to the consumer market. Commercial attempts have often met with lackluster sales. The obstacles to realizing the potential of electronic or “smart” clothing are complex and interrelated. Here, we explore areas of significant potential for the development of smart clothing, and identify the design barriers to achieving commercialization of these applications in four major areas: functionality, manufacture, developmental practice, and consumer acceptance.

Development and user evaluation of a virtual rehabilitation system for wobble board balance training

We have developed a prototype virtual reality-based balance training system using a single inertial orientation sensor attached to the upper surface of a wobble board. This input device has been interfaced with Neverball, an open source computer game to create the balance training platform. Users can exercise with the system by standing on the wobble board and tilting it in different directions to control an on-screen environment. We have also developed a customized instruction manual to use when setting up the system. To evaluate the usability our prototype system we undertook a user evaluation study with twelve healthy novice participants. Participants were required to assemble the system using an instruction manual and then perform balance exercises with the system. Following this period of exercise VRUSE, a usability evaluation questionnaire, was completed by participants. Results indicated a high level of usability in all categories evaluated.

Detecting bends and fabric folds using stitched sensors

In this paper we describe a novel method for detecting bends and folds in fabric structures. Bending and folding can be used to detect human joint angles directly, or to detect possible errors in the signals of other joint-movement sensors due to fabric folding. Detection is achieved through measuring changes in the resistance of a complex stitch, formed by an industrial coverstitch machine using an un-insulated conductive yarn, on the surface of the fabric. We evaluate self-intersecting folds which cause short-circuits in the sensor, creating a quasi-binary resistance response, and non-contact bends, which deform the stitch structure and result in a more linear response. Folds and bends created by human movement were measured on the dorsal and lateral knee of both a robotic mannequin and a human. Preliminary results are promising. Both dorsal and lateral stitches showed repeatable characteristics during testing on a mechanical mannequin and a human.

Theory and characterization of a top-thread coverstitched stretch sensor

One of the chief challenges of wearable sensing is adapting electronic components and sensors to the wearable environment. Electronic components are often rigid, bulky, and impermeable: factors that usually detract from wearing comfort. Here, we present a novel stretch sensor fabricated using the top thread of a standard industrial coverstitch machine. The machine is common in apparel production and offers the ability to easily fabricate custom-placed stretch sensors on textile and apparel products. The sensing properties of the stitch are enabled by a conductive thread which increases its electric resistance as the fabric is stretched, due to the geometry of the stitches. Our empirical analysis shows a sensor response in the order of 10 ohms, with almost linear behavior prior to saturation (when the stitch is fully stretched) for low-frequency extensions of 119% of initial sample length. An equivalent electrical model is presented for theoretical modeling of the sensor behavior.