Effects of pressure exerted on the skin by elastic cord on the core temperature, body weight loss and salivary secretion rate at 35 degrees C

Pressure and Thermal Behavior of Elastic Polyurethane and Polyamide Knitted Fabrics for Compression Textiles

Compression stockings have long been manufactured in a single color without patterns, but enhancing their aesthetic appeal through knitted designs can improve user compliance. This study explores the potential of punch lace knitted structures to create patterns in compression textiles by seamless knitting technology while maintaining sufficient pressure. The effects of yarn material, number of yarns used, and knitted patterns on pressure and thermal comfort will be studied. The fabric pressure was evaluated using pressure sensors with a leg mannequin, while the thermal properties were measured according to the textile standard. This study found that the pressure and thermal conductivity of fabric are significantly influenced by the number of yarn and yarn materials, but not the knitted pattern. Cupro/cotton/polyurethane yarn (A) exhibits the strongest positive impact on pressure, increasing by 2.03 mmHg with the addition of one end of yarn A while polyamide/lycra yarn (C) exhibits a higher thermal conductivity than yarn A. For air permeability, the number of yarn and knitted patterns significantly affects the ventilation resistance. Pattern B with an additional needle in a float stitch shows 0.023 kPa·s/m lower resistance than pattern A. The findings from this study can be widely used in health, medical, and sports applications.

Development of a comfort suit-type soft-wearable robot with flexible artificial muscles for walking assistance

Anchoring components are added to wearable robots to ensure a stable interaction between the suits and the human body and to minimize the displacement of the suits. However, these components can apply pressure to the body and can cause user dissatisfaction, which can decrease willingness to use the suits. Therefore, this study aims to develop a suit-type soft-wearable robot platform for walking assistance by providing comfortable garment pressure to ensure user satisfaction. The first prototype of a wearable robot suit was developed with anchoring components on the shoulders, waist, and thighs based on previous research results. Wear tests were conducted to measure garment pressure depending on posture using pressure sensors, and satisfaction surveys were conducted. The second prototype design was then developed, and performance tests with flexible artificial muscles and a satisfaction survey were conducted. Regarding the first prototype, the participants felt more than normal pressure in the shoulders and relatively less pressure in the thighs and calves. Thus, compared to the first design, the second design ensured a decreased garment pressure and resulted in an improvement of overall user satisfaction. These results can help provide guidance in the development of wearable robots by taking pressure comfort and user satisfaction into consideration.

Study on the Compression Effect of Clothing on the Physiological Response of the Athlete

The study aimed to analyze whether the high compression of unique, tight-fitting sportswear influences the clothing physiology comfort of the athlete. Three specific sportswear with different compression were tested on four subjects while they were running on a treadmill with increasing intensity. The compression effect of the sportswear on the body of the test persons, the temperature distribution of the subjects, and the intensity of their perspiration during running were determined. The results indicate that the compression effect exerted by the garments significantly influences the clothing physiology comfort of the athlete; a higher compression load leads to more intense sweating and higher skin temperature.

Pillow Support Model with Partitioned Matching Based on Body Pressure Distribution Matrix

(1) Objective: Sleep problems have become one of the current serious public health issues. The purpose of this research was to construct an ideal pressure distribution model for head and neck support through research on the partitioned support surface of a pillow in order to guide the development of ergonomic pillows. (2) Methods: Seven typical memory foam pillows were selected as samples, and six subjects were recruited to carry out a body pressure distribution experiment. The average value of the first 10% of the samples in the comfort evaluation was calculated to obtain the relative ideal body pressure distribution matrix. Fuzzy clustering was performed on the ideal matrix to obtain the support surface partition. The ideal body pressure index of each partition was calculated, and a hierarchical analysis of each partition was then performed to determine the pressure sensitivity weight of each partition. Using these approaches, the key ergonomic node coordinates of the partitions of four different groups of people were extracted. The ergonomic node coordinates and the physical characteristics of the material were used to design a pillow prototype. Five subjects were recruited for each of the four groups to repeat the body pressure distribution experiment to evaluate the pillow prototype. (3) Results: An ideal support model with seven partitions, including three partitions in the supine position and four partitions in the lateral position, was constructed. The ideal body pressure distribution matrix and ideal body pressure indicators and pressure sensitivity weights for each partition were provided. The pillow that was designed and manufactured based on this model reproduced the ideal pressure distribution matrix evaluated by various groups of people. (4) Conclusion: The seven-partition ideal support model can effectively describe the head and neck support requirements of supine and lateral positions, which can provide strong support for the development of related products.

Highly Sensitive and Durable Structured Fibre Sensors for Low-Pressure Measurement in Smart Skin

Precise measurements of low pressure are highly necessary for many applications. This study developed novel structured fibre sensors embedded in silicone, forming smart skin with high sensitivity, high durability, and good immunity to crosstalk for precise measurement of pressure below 10 kPa. The transduction principle is that an applied pressure leads to bending and stretching of silicone and optical fibre over a purposely made groove and induces the axial strain in the gratings. The fabricated sensor showed high pressure sensitivity up to 26.8 pm/kPa and experienced over 1,000,000 cycles compression without obvious variation. A theoretical model of the sensor was presented and verified to have excellent agreement with experimental results. The prototype of smart leg mannequin and wrist pulse measurements indicated that such optical sensors can precisely measure low-pressure and can easily be integrated for smart skins for mapping low pressure on three-dimensional surfaces.

Compression Garments for Medical Therapy and Sports

Compression garments are elastic clothing with an engineered compression gradient that can be worn on limbs, upper, lower, or full body to use for therapy and sports. This article presents an overview and review on the compression garments and concentrates on the design of compression garments with an appropriate pressure for specific applications. It covers the types of compression garments, fibers and yarns, knitted fabric construction, garment design, an evaluation system, and pressure measurement and modeling. The material properties, fabric properties, pressure modeling, and the garment design system presents the prediction, design, and fabrication of the compression garments. Lastly, the research status and directions are discussed.

Upper Body Compression Garment: Physiological Effects While Cycling in a Hot Environment

OBJECTIVE

The purpose of the present study was to investigate the effects of an upper body compression garment (UBCG) on physiologic and perceptual responses while cycling in a hot environment.

METHODS

Twenty recreational road cyclists were pair-matched for age, anthropometric data, and fitness level (V̇O_2max) and randomly assigned to a control (CON) group (n=10) of cyclists who wore a conventional t-shirt or to a group (n=10) of cyclists who wore UBCG. Test session consisted of cycling at a fixed load (~50% V̇O_2max) for 30 minutes at an ambient temperature of ~40ºC (39.9±0.4ºC), followed by 10 minutes of recovery.

RESULTS

Significantly greater (P = .002) rectal temperature (T_rec) was observed at the end of exercise in the UBCG group (38.3±0.2ºC) versus CON group (37.9±0.3ºC). Significantly greater heart rate (HR) was observed in the UBCG group at minute 15 (P = .01) and at the end of exercise (187±9 vs 173±10 beats/min; P = .004) for UBCG and CON, respectively. Furthermore, participants who wore UBCG perceived a significantly greater (P = .03) thermal sensation at the end of exercise. During recovery HR and T_rec remained significantly greater (P < .05) in the UBCG group.

CONCLUSIONS

The use of an UBCG increased cardiovascular and thermoregulatory strain during cycling in a hot environment and did not aid during recovery.

Effect of heat, cold, and pressure on the transverse carpal ligament and median nerve: a pilot study

Background

This study quantified the effects of heat, cold, and pressure on the median nerve and transverse carpal ligament in subjects without carpal tunnel syndrome.

Material/Methods

Subjects were individuals ages 20–50 who had no symptoms of carpal tunnel disease. Imaging ultrasound was used to measure the clearance around the median nerve, transverse ligament elasticity, nerve conduction velocity, thickness of the carpal ligament, and area of the median nerve. Pressure was applied to the carpal ligament to assess the effects of increasing pressure on these structures. On 3 separate days, 10 subjects had ThermaCare heat or cold packs applied, for either 60 or 120 minutes for heat or 20 minutes for cold, to the palmer surface of the hand.

Results

Tissue changes were recorded as a response to pressure applied at 0, 5, 10, and 20 N. The size of the nerve and ligaments were not significantly altered by pressure with the hand at room temperature and after cold exposure. After heat, the nerve, ligaments, and tendons showed significantly more elasticity.

Conclusions

Application of cold to the hand may reduce compression of the carpal ligament and nerve.

Effects of skin pressure from compression legwear on resting salivary cortisol and urinary catecholamines excretion in women

BACKGROUND

The benefits of compression legwear (CL) have been demonstrated in the improvement of vascular function and venous return of the lower extremities, but their effect on autonomic nervous system (ANS) activities and human stress response remain controversial.

OBJECTIVE

To investigate the possible effects of CLs on ANS activities and in inducing stress on the human body.

MATERIALS AND METHODS

Resting salivary cortisol and urinary catecholamine (adrenaline and noradrenaline) excretions were examined in 12 healthy women. The effects of different skin pressure levels exerted by CL were studied by conducting a 4-hour prolonged standing and sitting wear trial with intermittent sampling of the aforementioned biochemical parameters.

RESULTS

No statistically significant differences in resting salivary cortisol and urinary catecholamines were found between control and different clothing pressure conditions (light, mild, moderate, and strong), although the secretion of salivary cortisol (SSC) showed a significant decrease during the 180 minutes of the testing period that was maintained up to 10 minutes after the CL was removed for the studied pressure conditions. Urinary excretion of adrenaline and noradrenaline decreased with increasing pressure levels and was lower in response to higher clothing pressure when tested in the afternoon.

CONCLUSION

Constant pressure exerted by CL did not cause any stimulation of the sympathetic nervous system. The prolonged wearing of CL while standing or sitting did not induce any stress on the human body, suggesting that CL can be safely used in the treatment of patients with venous disorders of the lower extremities.