Development of a Novel Multi-Stage Limb Salvage Technology for the optimisation of tissue viability in severely injured limbs.

目的：开发一种用于保存战场损伤或严重创伤所致肢体组织的综合技术。总体目标是在撤离过程中使用基于其他医学领域（如心脏手术和器官运输）组织保存技术的新技术来稳定伤员并提高组织活力。本研究要解决的基本研究问题是“在损伤点快速隔离和冷却肢体，并结合孤立灌注，是否能提高组织活力和最终的肢体恢复？”新颖工程：该项目将重点研究新型交替气动止血带和局部气体冷却对模拟伤员疏散环境中组织活力的影响。然后将保留的肢体放置在具有自动控制系统的体外循环支持系统上，通过组织血氧仪和激光多普勒血流测量来监测四肢的循环充分性，以重新建立肢体的灌注。灌注一段时间后，通过神经刺激和组织学评估保存技术的影响。最后阶段评估的结果用于通知有关影响早期保存步骤充分性的因素的决定。使用红外热像仪技术进行了额外的体外实验，以评估不同冷却条件下离体组织的温度分布。使用这种方法，我们能够解释热延长对组织保存的积极和潜在的负面影响，以调整冷却周期，例如防止由于该技术导致的表面冻伤。这些不同的调查技术的使用，结合新的便携式组织保存技术的发展，代表了急诊医学领域的一种全新的工程方法。

Objectives:To develop an integrated technology for the preservation of tissue in injured limbs as a result of battlefield injury or severe trauma. The overall objective is to stabilise the casualty and to enhance tissue viability during the evacuation process using novel technologies founded on techniques employed for tissue preservation in other ranches of medicine such as cardiac surgery and organ transportation. The fundamental research question being addressed by this research is "Does rapid isolation and cooling of limbs at the point of injury, combined with isolated perfusion, enhance tissue viability and ultimate limb recovery?"Novel engineering:The project will focus on the impact of combined novel alternating pneumatic tourniquet and topical gas cooling of the tissues on tissue viability in a simulated casualty evacuation environment. The preserved limbs are then placed on an extracorporeal circulatory support system with an automated control system to re-establish perfusion to the limbs with adequacy of circulation monitored using tissue oximetry and laser Doppler flow measurement. The impact of the preservation technique is assessed using nerve stimulation and histological assessment after a period of perfusion. The results of the end stage assessment is used to inform decisions regarding the factors influencing the adequacy of the early preservation steps. Additional in-vitro experiments are carried out to assess the temperature profile of isolated tissue under differing cooling conditions, using infra-red thermal camera techniques. Using this approach, we are able to interpret the positive and potential negative impact of thermal prorogation on tissue preservation to tune the cooling cycle, for example to prevent surface frost bite as a consequence of the technique. This use of these various investigative techniques, combined with the development of new portable tissue preservation technologies are represent an entirely novel engineering approach in this field of emergency medicine.