한냉물리치료기의 개발

The Development of a Cryotherapy System

신냉매인 R-404A를 사용하여 저온특성이 우수한 한냉물리치료기를 개발하였다. 임상평가를 통해서 침온도계를 슬관절 강 내 및 둔부근육 내에 삽입하여 직접 근육온도를 측정하였고, 적외선체열촬영기를 이용하여 표피온도를 객관적으로 측정하였다. 슬관절 부위에 대한 5분 동안의 한냉물리치료에 따른 표피 및 관절강 내 온도변화를 측정한 결과, 표피는 23.3${\pm}4.7^{circ}C$, 관절강 내는 4.1${\pm}1.0^{circ}C$의 온도저하를 보였으며 2~3시간이 경과한 후에도 한냉치료효과가 지속됨을 알 수 있었다. 냉기치료 후 둔부근육에서 측정된 최저온도는 2, 4, 6cm 깊이에서 각각 35.1${\pm}$0.7, 36.2${\pm}$0.4, 36.9${\pm}0.3^{circ}C$였고, 이에 도달하기까지의 시간은 각각 20${\pm}$3.0, 25${\pm}$4.5, 45${\pm}$8.5분이었다. 치료 후 2시간이 경과한 뒤의 온도는 근육의 2, 4, 6cm 깊이에서 각각 36.2${\pm}$0.5, 36.6${\pm}$0.3, 36.9${\pm}0.3^{circ}C$였고, 치료 전에 비해 유의한 온도 차이가 있었다. 또한 5분간 한냉을 가하는 동안 피부 및 근육 내에서 온도의 증가, 즉 반응성 혈관확장은 관찰되지 않았다. 본 연구를 통해서 개발된 한냉물리치료기는 근육의 연축 혹은 강직, 물리적 외상, 화상, 동통의 감소, 관절염 등에 효과적으로 사용되리라 생각된다.

A cryotherapy system using cold air was developed. The developed system had superior low-temperature characteristics with various flow rates and nozzle sizes, and used R-404A, as a coolant, which has no destructive effects of Ozone layers. Flow rates and the treatment time can be easily altered during the operation. In addition, and alarm system was designed for the overload, overheat, and over-charge of the machine. For clinical applications, skin temperatures, intra-articular temperatures of the knee joint and intra-muscluar temperatures of the gluteal muscles were measured during and after the cryotherapy. After a 5-minute therapy, skin and intra-articular temperatures decreased by $23.3{\pm}4.7 and 4.1 {\pm}1.0^{circ}C$, respectively. A 5-minute cryotherapy was good enough to maintain low intra-articular temperatures for 2-3 hours. Resting intra-muscular temperatures in 2, 4, and 6cm deep in the gluteal muscle were $36.5{\pm}1.2, 36.9{\pm}0.2, 37.1{\pm}0.2^{circ}C$, respectively (p<0.05). Lowest temperatures in 2, 4, and 6cm depth were $35.1{\pm}0.7, 36.2{\pm}0.4, 36.9{\pm}0.3^{circ}C$, respectively (p<0.05). Temperatures after a 2-hour cold air application on the skin and in the muscle in dept도 of 2, 4, and 6cm were $32.2{\pm}1.1, 36.2{\pm}0.5, 36.6{\pm}0.3, 36.9{\pm}0.3^{circ}C$respectively (p<0.05). Temperatures on the skin and in the muscle significantly decreased after 2 hours, compared with before cold air application (p<0.05). The intra-muscular temperature was changed more slowly than the skin temperature, and the deeper the muscle, the lesser temperature changes. The effect of a 5-minute cold air application lasts up to 2 hours, and it seems that the rebound-rise of the temperature dut to the reactive vasodilatation does not occur in the gluteal muscle.