一种激光散斑和温度刺激仪器在压疮早期诊断的研究

Early diagnosis studies of pressure ulcer with laser speckle and temperature stimulation instrument

目的设计了一款具有血流成像以及温度刺激功能的系统,用于测量压疮区域与非压疮区域的特征,并通过对动物压疮模型进行参数测量,验证该系统在早期压疮诊断中的作用。方法系统主要由相机、环形光源、激光二极管、长焦温度传感器及液氮喷射器组成,可以实现激光散斑血流成像,同时利用液氮喷射器给皮肤降温,使该系统获取皮肤动态血流特性。采用脂肪乳模拟血流,验证该系统血流速度测量的准确性。通过对5只兔子的背部进行压力装置下的加压200 mmHg(1 mmHg=133.3Pa)持续1 h,再恢复血流灌注20 min,反复两次,制作出早期压疮模型。利用该系统对动物压疮模型降温之前到降温再到恢复的整个过程进行血流成像及血流参数分析。结果系统性能测试结果中,该系统测量的散斑值得到的流速与脂肪乳实际的流速成正比关系。动物实验测试结果中,非压疮区域与压疮区域的制冷后恢复时间(time to peak)分别为89.88 s±5.70 s和112.69 s±19.67 s,差异具有统计学意义,可作为压疮区域与非压疮区域的区分特征。结论本研究设计的系统为早期压疮诊断提供了一种新的方法和思路。

Objective In this study,an instrument with blood flow imaging and temperature stimulation was designed to measure the characteristics of pressure ulcer areas and non-pressure ulcer areas,and the parameters of animal pressure ulcer models were measured to verify the instrument effect in the early diagnosis of pressure ulcers.Methods The system was mainly composed of a camera,a ring light source,a laser diode,a telephoto temperature sensor,and a liquid nitrogen injector.It could realize laser speckle blood flow imaging,and use a liquid nitrogen jet cooling the skin to obtain the dynamic blood flow characteristic of the skin.We used fat emulsion to simulate blood flow to verify the accuracy of the blood flow velocity measurement of the system.Early pressure ulcer model for 5 rabbits was created by applying pressure of 200 mmHg(1mmHg=133.3Pa)on the back of rabbit under pressure for 1 h,and then restoring blood flow for 20 min,and repeating it twice.The instrument was used to perform blood flow imaging and blood flow parameter analysis on the whole process of the animal pressure ulcer model from temperature reduction to the temperature recovery.Results In the system performance test results,the flow rate obtained by the speckle value measured by the system is directly proportional to the actual flow rate of the fat emulsion.In animal experiment results,the time to peak of the non-pressure ulcer area and the pressure ulcer area were 89.88 s±5.70 s and 112.69 s±19.67 s.And the P value was 0.037,which had a significant difference,could be used as the distinguishing feature between the pressure ulcer area and the non-pressure ulcer area.Conclusions The instrument designed in this study provides an objective method and a new idea for early diagnosis of pressure ulcers.