Correction of temperature measured by insole sensors for diabetic foot diagnosis based on pressure effect reduction

healthcare;non-invasive measurement;skin temperature;pressure-error-correction function;foot ulcer;헬스케어;무구속 측정;피부온도;압력보정함수;족부궤양;660

공과대학 협동과정 바이오엔지니어링전공 ;

University:서울대학교 대학원

关键词: healthcare;    non-invasive measurement;    skin temperature;    pressure-error-correction function;    foot ulcer;    헬스케어;    무구속 측정;    피부온도;    압력보정함수;    족부궤양;    660;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/122437/1/000000021150.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

however, there are factors that affect in monitoring plantar foot skin temperature which bear error in the result especially when comparing the temperature difference of corresponding points (Toe, 1st, 3rd metatarsal and Heel) between left and right foot (≥1.2 C˚ difference for early diagnosis of foot ulcer). In this study, we only focused on pressure as the only factor that affects foot plantar skin temperature and we investigated how the pressure affects the skin temperature in plantar foot and propose the function to correct the error caused by the pressure.Methods: We performed calibration for each thermistor before the experiment in the temperature range from 25 to 40°C. We used thermistor-embedded insole in measuring skin temperature of corresponding points which are toe, 1st, 3rd metatarsal and heel from both feet. We used pressure sensor and three stages of pressure (No pressure, standard, focused) were applied on plantar foot surface and in each stage, the voltage values were received and converted into the temperature values using the equations obtained from calibration by using Matlab. Once the data were received, we analyzed the trend of temperature changes as the pressure increases. Also, by investigating relationship between the amount of temperature changes and that of pressure changes, we were able to get the pressure-error-correction function. By using this function, we applied this to the subjects while they put more pressure on either left or right foot, so that we can check if the function can reduce the error.Results: The experimental results show that as the pressure increases, the temperature decreases. This implies that because of less blood flow caused by pressure applied on the plantar foot surface, the skin temperature decreases and this trend is similar to those on other parts of the body. When we applied the pressure-error-correction function to the subjects, the errors were reduced and this shows that by using this method, we were able to reduce the false alarm.Conclusions: This study proved that as the pressure on the plantar foot surface increases, the plantar foot skin temperature decreases. We were also able to reduce the error in skin temperature monitoring caused by the pressure using pressure-error-correction function and showed that it can be applied to sensor-embedded insole independent from the person’s standing habit.