Flexible Sensors for Pressure Therapy: Effect of Substrate Curvature and Stiffness on Sensor Performance.

Flexible pressure sensors are increasingly being used in medical and non-medical applications, and particularly in innovative health monitoring. Their efficacy in medical applications such as compression therapy depends on the accuracy and repeatability of their output, which in turn depend on factors such as sensor type, shape, pressure range, and conformability of the sensor to the body surface. Numerous researchers have examined the effects of sensor type and shape, but little information is available on the effect of human body parameters such as support surfaces' curvature and the stiffness of soft tissues on pressure sensing performance. We investigated the effects of body parameters on the performance of pressure sensors using a custom-made human-leg-like test setup. Pressure sensing parameters such as accuracy, drift and repeatability were determined in both static (eight hours continuous pressure) and dynamic (10 cycles of pressure application of 30 s duration) testing conditions. The testing was performed with a focus on compression therapy application for venous leg ulcer treatments, and was conducted in a low-pressure range of 20-70 mmHg. Commercially available sensors manufactured by Peratech and Sensitronics were used under various loading conditions to determine the influence of stiffness and curvature. Flat rigid, flat soft silicone and three cylindrical silicone surfaces of radii of curvature of 3.5 cm, 5.5 cm and 6.5 cm were used as substrates under the sensors. The Peratech sensor averaged 94% accuracy for both static and dynamic measurements on all substrates; the Sensitronics sensor averaged 88% accuracy. The Peratech sensor displayed moderate variations and the Sensitronics sensor large variations in output pressure readings depending on the underlying test surface, both of which were reduced markedly by individual pressure calibration for surface type. Sensor choice and need for calibration to surface type are important considerations for their application in healthcare monitoring

Evaluation of Flexible Force Sensors for Pressure Monitoring in Treatment of Chronic Venous Disorders.

The recent use of graduated compression therapy for treatment of chronic venous disorders such as leg ulcers and oedema has led to considerable research interest in flexible and low-cost force sensors. Properly applied low pressure during compression therapy can substantially improve the treatment of chronic venous disorders. However, achievement of the recommended low pressure levels and its accurate determination in real-life conditions is still a challenge. Several thin and flexible force sensors, which can also function as pressure sensors, are commercially available, but their real-life sensing performance has not been evaluated. Moreover, no researchers have reported information on sensor performance during static and dynamic loading within the realistic test conditions required for compression therapy. This research investigated the sensing performance of five low-cost commercial pressure sensors on a human-leg-like test apparatus and presents quantitative results on the accuracy and drift behaviour of these sensors in both static and dynamic conditions required for compression therapy. Extensive experimental work on this new human-leg-like test setup demonstrated its utility for evaluating the sensors. Results showed variation in static and dynamic sensing performance, including accuracy and drift characteristics. Only one commercially available pressure sensor was found to reliably deliver accuracy of 95% and above for all three test pressure points of 30, 50 and 70 mmHg

Examination of the effects of a new compression garment on skin tissue oxygenation in healthy volunteers

Objective: Compression devices have been shown to reduce venous stasis, increase blood flow and skin tissue oxygenation (StO2), promoting healthy tissue. This study aimed to explore the efficacy of a new compression garment in three different positions in healthy adults. Methods: In this quantitative study, potential participants were screened and recruited using the Physical Activity Readiness Questionnaire (PAR-Q, Canada). Participants attended three separate, one-hour sessions to evaluate StO2 in supine-lying, chair-sitting and long-sitting positions. StO2 was recorded for 20 minutes pre-, during and post- a 20-minute intervention using a compression garment, TributeWrap (Lohmann-Rauscher, Germany). A repeated-measures analysis of variance (ANOVA) was followed by post-hoc pairwise comparisons. Results: A total of 28 healthy volunteers took part (aged 24.6 ±8.4years; 13 males, 15 females). A significant difference was seen between the three positions (p<0.001). Chair-sitting had the lowest StO2 pre-intervention, increasing StO2 significantly (32.25%, p<0.001) during wear of the compression garment (24.8% higher than baseline post-intervention). No significant difference was seen between long sitting and supine-lying (p=1.000). In contrast, long-sitting and supine-lying StO2 was higher pre-intervention compared with chair-sitting and only increased post-intervention (11% and 16.8% respectively, p<0.001) compared with baseline. Conclusion: The compression garment significantly increased StO2 levels in both seating positions. Further studies are required to determine if increasing StO2 through short intervention sessions with this device has the potential to improve self-management of tissue health in individuals with reduced mobility, oedema or venous insufficiency

Smart body - ergonomic seamless sportswear design and development

Abstract not availabl

Knitting technology for seamless sportswear

Abstract not availabl

Therapeutic gloves for arthritis: development of a design framework

Therapeutic gloves are an intervention widely recommended and prescribed by rheumatologists and occupational therapists for the management and treatment of hand arthritis. Different models of therapeutic gloves are commercially available, with varying design, construction and materials. However, a systematic classification for therapeutic gloves and their effectiveness has not been well established. In addition, little research has addressed the issue of material choice on glove performance. These knowledge gaps prompted the development of a framework for the design and engineering of functional and comfortable therapeutic gloves. Knowledge from multiple domains was integrated into a single framework and relationships between components were identified and characterised. The framework demonstrates that the design and engineering of therapeutic gloves requires fusion of functional design with comfort design to meet users&#039; demand for wearing comfort, relief of arthritic symptoms and improvement of hand function

Moisture management properties of wool/polyester and wool/bamboo knitted fabrics for the sportswear base layer

This research seeks to investigate liquid moisture management properties of knitted fabrics of different wool/polyester and wool/bamboo blends of different ratios suitable for the base layer of sportswear. The fabrics were knitted in single jersey construction and their moisture management properties were assessed by using the Moisture Management Tester. Blending wool with polyester or wool with bamboo has improved moisture management properties of the fabrics in comparison to 100% wool and 100% bamboo fabrics. Out of nine fabrics studied, five fabrics were classified as moisture management fabrics that are suitable for the base layer of active sportswear

Thermoregulatory evaluation of triathlon suits in regards to their physiological comfort properties

In this study 3 commercially available triathlon suits, one baseline level and 2 specialised suits, and their comprising materials are evaluated in terms of thermoregulatory performance, namely Dry Thermal Resistance, Evaporative Resistance and Permeability Index. Objective evaluation of thermal characteristic of these suits and materials is carried out by means of a Thermal Manikin where the data acquired in static, non-perspiring and perspiring conditions. Varied skin surface and sweating rates are allocated to different body zones relative to the triathlon activity, performance of the suits is evaluated, and the factors affecting their thermoregulatory characteristics are identified. The study demonstrated that the physiological comfort properties of triathlon suits are determined by both the fabrics and materials used and also the design and construction of the garments. It is possible by altering the design of the garment and, most importantly, by selection of the materials with relevant performance attributes, to engineer the garments with optimal performance

Anisotropic friction of rugby ball surfaces

In irregular, isotropic surface patterns with randomly distributed roughness elements, the kinetic coefficient of friction is expected to be independent of sliding direction. In regular, anisotropic surface patterns, at least two directions are expected to have different friction coefficients