A Comparative Study on the Effectiveness of Evaporative and Phase Change Material Cooling Vests for People With Paraplegia

Abstract Personal cooling vests to alleviate thermal strain in persons with thoracic spinal cord injury (SCI), named paraplegia, were tested. Mainly, phase change material (PCM) cooling vests were the most frequent type applied at different exercises and ambient conditions. Published results of PCM cooling vests indicated its significant effect in reducing body core temperature for persons having more than 50% of their trunk skin as sensate. Nevertheless, preferences of persons with SCI obtained from subjective voting during experimental studies revealed that the use of PCM cooling vests caused additional burden weight on the body and sometimes restricted the movement. It is of interest to investigate the effect of an alternative personal evaporative cooling vest (ECV), characterized by light weight and practical use without hindering body movement of persons with SCI. In this study, it is aimed to compare the effect of ECV on the physiological and psychological responses of persons with SCI compared to that of PCM cooling vests under the same ambient conditions and metabolic rates. The research methodology included human subject experiments for persons with mid-thoracic (T4-T8) and low-thoracic (T9-T12) injury where the sensate skin of the trunk is at least 50% of its area. Thirteen participants were recruited to perform an arm-crank exercise at a constant load of 30 W for 30-min while using ECV inside a controlled climatic chamber of hot conditions (30°C, 4 0% RH). Measurements of body core and skin temperatures as well as thermal comfort and sensation, perceived exertion and skin wettedness were done. Furthermore, Multi-way ANOVA test was conducted to analyse the results of three tests: no vest (NV), with ECV, and with PCM. Findings of mid- and low-thoracic groups showed similar effectiveness of ECV compared to PCM cooling vest in reducing core temperature, yet the change in perceived exertion was better with the use of ECV due to its light weight.

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Experiment Study for Evaluation of Phase Change Material Cooling Vest’s Effectiveness at Two Melting Points Used by People With Paraplegia During Exercise

Volume 11: Heat Transfer and Thermal Engineering ◽

10.1115/imece2020-23083 ◽

2020 ◽

Author(s):

Farah Mneimneh ◽

Nesreen Ghaddar ◽

Kamel Ghali ◽

Charbel Moussalem ◽

Ibrahim Omeis

Keyword(s):

Thermal Comfort ◽

Phase Change ◽

Phase Change Material ◽

Core Temperature ◽

Perceived Exertion ◽

Ambient Conditions ◽

Melting Points ◽

Cord Injury ◽

Change Material ◽

Skin Temperatures

Abstract Phase change material (PCM) cooling vests were tested on people with thoracic (T1-T12) spinal cord injury (SCI), also called people with paraplegia (PA), during exercise in heat. The purpose was to reduce heat stress, limit the increase in core temperature, and improve thermal comfort for PA under high metabolic rates and hot ambient conditions. This health risk was a result of thoracic SCI and disruption of thermoregulatory responses in PA. The current study aims to evaluate the efficacy of cooling vest on PA during arm-crank exercise at two melting points, 20°C (V20) and 14°C (V14) compared to no vest test (NV). Eleven participants with high- (T1-T3) and mid-thoracic SCI (T4-T8) were selected to participate in three tests. Core and skin temperatures and heart rate values were measured during 15-min precondition, 30-min exercise and 15-min recovery. Subjective voting of thermal comfort, sensation, skin wettedness and perceived exertion were recorded during exercise only. The main findings revealed significant reduction in change in core temperature (0.42±0.3°C;0.38±0.2°C) in V20 and V14 compared to NV tests for mid-thoracic group. For high-thoracic group, V20 and V14 were least effective in reducing core temperature (p > 0.05). Improvements in thermal comfort was established when using V14 and V20 compared to NV by 85% and 30% for high-thoracic group and by 72% and 53% for mid-thoracic group.

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Long-Term Solar Energy Storage under Ambient Conditions in a MOF-Based Solid–Solid Phase-Change Material

Chemistry of Materials ◽

10.1021/acs.chemmater.0c02708 ◽

2020 ◽

Vol 32 (23) ◽

pp. 9925-9936

Author(s):

Kieran Griffiths ◽

Nathan R. Halcovitch ◽

John M. Griffin

Keyword(s):

Energy Storage ◽

Solar Energy ◽

Phase Change ◽

Phase Change Material ◽

Solid Phase ◽

Ambient Conditions ◽

Solar Energy Storage ◽

Change Material

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Effect of Phase Change Material Cooling Vests on Body Thermoregulation and Thermal Comfort of Patients With Paraplegia: A Human Subject Experimental Study

Global Spine Journal ◽

10.1177/21925682211049167 ◽

2021 ◽

pp. 219256822110491

Author(s):

Charbel K. Moussalem ◽

Farah Mneimneh ◽

Rana Sarieddine ◽

Shadi Bsat ◽

Mohamad N. El Houshiemy ◽

...

Keyword(s):

Experimental Study ◽

Thermal Comfort ◽

Phase Change ◽

Phase Change Material ◽

Recovery Period ◽

Thoracic Spinal Cord ◽

Increased Risk ◽

Cord Injury ◽

Cooling Effects ◽

Change Material

Study design Randomized experimental study. Objective Compared to able-bodied people, patients with paraplegia due to thoracic spinal cord injury (SCI) are at an increased risk of heat illnesses during exercise due to impaired thermoregulatory responses. To overcome this limitation, we investigated the performance of three phase change material (PCM) cooling vests of different melting temperatures (Eijsvogels, #49) and coverage area of the trunk. Methods Sixteen participants were divided into three groups according to their injury level. All were tested for V20 full vest (20°C Tm, 75% coverage). Mid-thoracic and high-thoracic groups were tested for V14 vest (14°C Tm, 75% coverage). The mid-thoracic group was tested for V20 half vest (20°C Tm, 50% coverage). The participants performed a 30-min arm-crank exercise followed by a recovery period inside a controlled hot climatic chamber. The heart rate, segmental skin (Tskin), and core temperature (Tcore) values were recorded, and subjective questionnaires were taken. Results Compared to no vest (NV) test, all the vests showed an effective decrease in Tskin values of the trunk. However, the decrease in Tskin was not enough to induce a significant decrease in Tcore in all three groups. Mid-thoracic and low-thoracic groups showed a reduction in the increasing Tcore by the end of the exercise and recovery period. Finally, the level of thermal comfort was enhanced for the three groups. Conclusion The effectiveness of cooling vests for persons with paraplegia is dependent on injury level and thus the ratio of sensate to insensate skin. Future studies necessitate the investigation of the cooling effects of PCM vests at a lower Tm with a larger sample size.

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