Microenvironment temperature prediction between body and seat interface using autoregressive data-driven model

A novel skin temperature estimation system for predicting pressure injury occurrence based on continuous body sensor data: A pilot study

BACKGROUND

Pressure injury prevention is important in older patients with immobility. This requires an accurate and efficient prediction of the development of pressure injuries. We aimed to develop a method for estimating skin temperature changes due to ischemia and inflammation using temperature sensors placed under bedsheets to provide an objective, non-invasive, and non-constrained risk assessment tool.

METHODS

This study consisted of a thermal skin simulation study and a descriptive correlation study in healthy participants. A thermal skin simulation study was conducted using a model reproducing the body surface (underwear, diaper, or wet diaper conditions) and bed environment. In a descriptive-correlational study, the participants lay supine on a mattress with a temperature sensor attached to their sacral skin.

FINDINGS

The thermal skin simulation study showed that temperature changes in the skin can be estimated under the sheets by inputting time-shifted temperature data into machine learning (R2 = 0.9967 for underwear, 0.9950 for diapers, and 0.9869 for wet diapers). It was also demonstrated that the absolute skin temperature of a healthy individual (N = 17) could be estimated with the best accuracy by inputting time-shifted data into an extra-tree regressor (R2 = 0.8145).

INTERPRETATION

A combination of interface pressure and temperature sensors can be used to estimate skin temperature changes. These findings contribute to the development of a skin temperature measurement method that can capture temperature changes over time in clinical settings.

Hygro-thermo-mechanical performance of wheelchair cushion technologies in the prevention of pressure ulcers and moisture-associated skin damages

This study aims at investigating the effects of three different wheelchair cushion technologies at the patient-wheelchair interface. To this end, eight participants were recruited to remain in an unrelieved seated position on a wheelchair successively equipped with three different cushions (foam, air-cell-based and gel), for a duration of 45 min. Interface pressure, temperature (measured with infrared thermography) and relative humidity were measured at the seat interface, at different timestamps. Experimental results show that foam cushion is significantly more efficient in reducing contact peak pressure (p < .01), while the gel cushion displays higher heat evacuation capabilities. In terms of relative humidity, no significant difference is observed among the three technologies (p > .29): all of them evacuate around only 10% of the total humidity compared to the reference situation (i.e., without cushion). Besides, a complementary numerical simulation corresponding to the steady state of the patient-wheelchair structure clearly highlights the temperature volume field at the underside of the seat, which acts like a thermal barrier and contributes to heat accumulation. Besides, an air flow at the underside of the chair in motion is shown to significantly reduce heat accumulation.

Evaluation of interface pressure and temperature management in five wheelchair seat cushions and their effects on user satisfaction

BACKGROUND

Factors such as the manufacturing materials, shape or even the mechanical and thermal response of sitting Pressure Redistribution Support Surfaces (PRSS) can be potential contributors to pressure ulcers. However, few studies have compared a number of characteristics of the most frequently used devices.

OBJECTIVE

To compare three potential contributors to pressure ulcers in five commercial PRSS: pressure redistribution, temperature and perceived comfort.

METHOD

Study with a cross-over randomized design in healthy volunteer participants. Data was collected in a temperature and relative humidity controlled environment. To assess thermal response, the temperature (Flir-E60) of the region of interest was captured before and after use of each PRSS for further analysis. The region of interest was the gluteal zone. To assess the pressure redistribution a pressure mat (XSensor®) was used between the 5 cushion and each study participant using a standardized method. Finally, a subjective perception questionnaire recorded comfort, adaptability and thermal sensation parameters. Data analysis levels of significance were set at 0.05.

RESULTS

A total of 22 participants completed the assessments. There were no statistically significant differences in baseline temperatures between PRSS (>0.05). Pressure redistribution analysis showed significant differences between all PRSS in all variables evaluated except in the maximum and peak pressure index al sacrum. The subjective assessment suggested no major user-perceived differences between PRSS.

CONCLUSION

Seat cushions made of open cell polyurethane foam blocks of variable hardness and the horseshoe cushion (also open cell polyurethane foam) seem to provide a more effective pressure relief characteristic than those injected with polyurethane foam and gel in most of the studied pressure variables. However, the cushions provide similar thermal response and perceived comfort.

A method for culturing Gram-negative skin microbiota

Background

Commensal Gram-negative (CGN) microbiota have been identified on human skin by DNA sequencing; however, methods to reliably culture viable Gram-negative skin organisms have not been previously described.

Results

Through the use of selective antibiotics and minimal media we developed methods to culture CGN from skin swabs. We identified several previously uncharacterized CGN at the species level by optimizing growth conditions and limiting the inhibitory effects of nutrient shock, temperature, and bacterial competition, factors that may have previously limited CGN isolation from skin cultures.

Conclusions

Our protocol will permit future functional studies on the influences of CGN on skin homeostasis and disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-016-0684-9) contains supplementary material, which is available to authorized users.