Department of Mechanical Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
Med Biol Eng Comput. 2010 Aug;48(8):783-91. doi: 10.1007/s11517-010-0635-9. Epub 2010 Jun 4.
Brain hypothermia induced by a temperature reduction of the spinal fluid using a torso-cooling pad is evaluated as a cooling alternative for traumatic injury patients. A theoretical model of the human head is developed to include its tissue structures and their contribution to local heat transfer. The Pennes bioheat equation and finite element analysis are used to predict the temperature distribution in the head region. The energy balance in the cerebrospinal fluid (CSF) layer surrounding the brain during mixing of the CSF and cold spinal fluid is also formulated to predict the CSF temperature reduction. Results show that the presence of cooled CSF around the brain provides mild cooling (approximately 1 degrees C) to the grey matter within 3000 s (50 min) with a cooling capacity of approximately 22 W. However, large temperature variations (approximately 3.5 degrees C) still occur in the grey matter. This approach is more effective during ischemia because it promotes deeper cooling penetration and results in larger temperature reductions; the average grey matter temperature decreases to 35.4 degrees C. Cooling in the white matter is limited and only occurs under ischemic conditions. The non-invasive nature of the torso-cooling pad and its ability to quickly induce hypothermia to the brain tissue are beneficial to traumatic injury patients.
采用躯干冷却垫降低脑脊液温度来诱导脑低温，这一方法已被评估为创伤性损伤患者的一种冷却替代方法。本研究建立了一个包含人体头部组织及其对局部热传递贡献的理论模型。采用彭内斯生物传热方程和有限元分析来预测头部区域的温度分布。还制定了围绕大脑的脑脊液（CSF）层中 CSF 和冷脑脊液混合时的能量平衡方程，以预测 CSF 温度降低。结果表明，大脑周围冷却 CSF 在 3000 秒（50 分钟）内可对灰质提供温和的冷却（约 1 摄氏度），冷却能力约为 22 W。然而，灰质中仍会出现较大的温度变化（约 3.5 摄氏度）。在缺血期间，这种方法更为有效，因为它可以促进更深的冷却渗透并导致更大的温度降低；灰质的平均温度降低至 35.4 摄氏度。在非缺血情况下，白质的冷却受到限制。躯干冷却垫具有非侵入性，能够迅速将脑组织降温，这对创伤性损伤患者有益。
