臨床応用可能な脳低温療法のための表面冷却用水温自動制御装置の開発

抄録

To prevent secondary brain damage during brain hypothermia treatment, accurate control of the temperature of the brain tissue is necessary in order to avoid various side effects. However, the procedure for controlling brain temperature requires medical staffs with extensive clinical experience and specific knowledge of the equipment, and is available only in a limited number of hospitals. The authors have therefore developed a water-blanket temperature controller that automatically controls the brain temperature by water-surface cooling. The controller itself is sufficiently efficient for the quick and accurate control of water temperature, which is accomplished by mixing warm and cool water of definite constant temperatures based on a suitable algorithm. Controller performance has been verified to be sufficient, even under extreme conditions of large temperature changes in water-blanket heating and cooling. The brain temperature was regulated using the controller in simulation experiments where a mannequin was used instead of a patient. The mannequin had biothermal characteristics of normal human metabolic heat production and blood circulation with their possible changes given in the clinical simulation process, in which the brain temperature was more difficult to control than in the case of a normal adult. From the various experiments, it was demonstrated that the newly developed controller worked accurately in simulated clinical situations and performs well in brain hypothermia control systems using a mannequin. Thus, it is expected to be clinically useful for controlling temperature during an actual brain hypothermia treatment.