Core body temperature estimation by eyeglass-type device: thermal analysis of radiation heat measured from caruncle.

This paper describes a method for estimating core body temperature from radiation heat of the caruncle and an eyeglass-type device for measuring the temperature of the caruncle to prescreen for infectious diseases such as COVID-19. As a precise prescreening method, monitoring a person's continuous core body temperature is desired. By monitoring the continuous core body temperature, including circadian rhythm, in our daily life, infections can potentially be discovered when body temperature is higher than normal. Although monitoring the core body temperature is effective, continuous and precise monitoring requires the use of an invasive instrument. To overcome this, we (1) design an eyeglass-type device for measuring the caruncle temperature and (2) model the correlation between the caruncle temperature and the core body temperature. Experimental results revealed that hypothalamic temperature could be estimated within ± 0.3 °C between 20 and 30 °C by using the eyeglass-type device.

Development of ultrasound-assisted fluorescence imaging of indocyanine green.

PURPOSE: Indocyanine green (ICG) accumulation in hepatocellular carcinoma means tumors can be located by fluorescence. However, because of light scattering, it is difficult to detect ICG fluorescence from outside the body. We propose a new fluorescence imaging method that detects changes in the intensity of ICG fluorescence by ultrasound-induced temperature changes. METHODS: ICG fluorescence intensity decreases as the temperature rises. Therefore, it should theoretically be possible to detect tissue distribution of ICG using ultrasound to heat tissue, moving the point of ultrasound transmission, and monitoring changes in fluorescence intensity. A new probe was adapted for clinical application. It consisted of excitation light from a laser, fluorescence sensing through a light pipe, and heating by ultrasound. We applied the probe to bovine liver to image the accumulation of ICG. RESULTS: ICG emits fluorescence (820 nm) upon light irradiation (783 nm). With a rise in temperature, the fluorescence intensity of ICG decreased by 0.85 %/°C. The distribution of fluorescent ICG was detected using an ultrasonic warming method in a new integrated probe. CONCLUSION: Modulating fluorescence by changing the temperature using ultrasound can determine where ICG accumulates at a depth, highlighting its potential as a means to locate hepatocellular carcinoma.