Study of capillary refill time measurement way by nail detection and a pen-type compression device

• Published in: Transactions of Japanese Society for Medical and Biological Engineering Vol. Annual59; no. Abstract; p. 588
• Main Authors: Shimizu, Rika, Shinozaki, Masayoshi, Saito, Daiki, Yoshimura, Yuichiro, Nakada, Taka-aki, Nakaguchi, Toshiya
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society for Medical and Biological Engineering 2021
• ISSN: 1347-443X; 1881-4379
• DOI: 10.11239/jsmbe.Annual59.588

Capillary refill time (CRT) is an evaluation index for peripheral circulation in emergency medicine. However, CRT is conducted in variable ways due to lack of international guidelines. Therefore, we investigated a CRT measurement method that does not fix the fingertips by using a mobile device. The finger and nail are automatically detected from the camera image of the mobile device, and the change in the green component at the center of the nail is recorded to measure the color change of the nail. We also developed a pen-type compression device that uses a spring to measure with an appropriate compression force. By visualizing the force with the LED light or the change in the housing color, the measurer and software of mobile device can grasp the compression status. Through experiments, it was confirmed that the proposed system can perform acquisition of nail color recovery curve, and calculation of CRT value.