Detection of Spinal Cord Injury during Thoracoabdominal Aortic Aneurysm Surgery Using Multi-channel Superconducting Quantum Interference Device

本项目的主要目的是测试超导量子干涉装置(SQUID)，用于检测脊髓传导和预测脊髓缺血。(1)用于脊髓研究的SQUID系统的开发(在广岛大学)：使用单通道SQUID检测脊髓活动磁场失败。单通道器件的性能限制是这一失败的深层次原因。(2)脊髓缺血模型：采用夹闭成年犬胸主动脉60min的方法复制脊髓缺血模型。2002年4月，我们在日本横须贺NTT Docomo多媒体实验室开始使用高性能71通道鱿鱼进行研究。这种多通道装置的结果如下。(3)周围复合神经动作磁场(CAF)的测量及其空间分析：我们成功地测量了人正中神经和尺神经的CAF。脑磁图显示神经传导情况。(4)Magne…缺血所致神经传导障碍的更多抽动分析：我们用磁学研究成功地记录了正中神经传导的缺血性改变。用充气止血带缠绕上臂造成前臂缺血20分钟。正中神经CAF波幅在缺血后5min显著升高，20min后逐渐降低，几乎完全消失。磁学检查也显示了早期脑缺血的特征性表现。(5)用于脊髓研究的多通道SQUID系统的建立：a)兔脊髓活动磁场的建立利用磁学研究，我们仅在腰部成功地显示了脊髓的上行传导。B)-狗研究：由于传感器灵敏度不足，我们未能记录犬绳的磁场。如果这个问题解决了，我们将应用缺血方案来测试目前的多通道设备来检测脊髓缺血。较少

The main purpose of the current project was to test superconducting quantum interference device (SQUID), for detecting the spinal cord conduction and for predicting spinal cord ischemia. (1) Development of SQUID system for spinal cord study (at Hiroshima University) : Detection of spinal cord action magnetic field using one-channel SQUID failed. The limitation of the performance of the one-channel device was the profound cause of this failure. (2) Spinal cord ischemia model : Ischemia was induced in adult dogs by cross-clamping the thoracic aorta for 60 min.On April, 2002, we started to research using high performance 71-channel SQUID at NTT Docomo Multimedia Laboratories (Yokosuka, Japan). This multi-channel device has given results as follows. (3) Measurement of the peripheral compound nerve action magnetic field (CAF) and its spatial analysis : We succeeded in measuring the CAF of the human median and ulnar nerves. Nerve conduction was visualized by means of magnetography. (4) Magne … More tic analysis of ischemia-induced nerve conduction impairment : We succeeded in recording ischemic- changes of the median nerve conduction with magnetic study. Twenty -minute fore-arm ischemia was induced with the pneumatic tourniquet placing around the upper arm. The amplitude of the CAF of the median nerve significantly increased at 5 min after the initiation of ischemia, and it gradually decreased and almost completely disappeared at 20 min. Magnetographic evaluation also showed characteristic findings during early period of ischemia. (5) Development of multi -channel SQUID system for spinal cord study : A)-Spinal cord action magnetic field in rabbit ; We succeeded in visualization of ascending spinal cord conduction only in the lumbar area with magnetic study. B)-Dog study ; We failed to recording magnetic field of the canine cord because of insufficient sensor sensitivity. If this trouble is solved, we will apply an ischemia protocol for testing the current multi-channel device to detect spinal cord ischemia. Less