Tran Denis, Hor King-Wei, Kamani Allaudin A, Lessoway Victoria A, Rohling Robert N
Electrical and Computer Engineering Department, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
IEEE Trans Biomed Eng. 2009 Mar;56(3):820-7. doi: 10.1109/TBME.2008.2011475. Epub 2009 Jan 23.
Epidural anesthesia is the most common form of anesthesia in obstetrics. The loss-of-resistance to saline injection is used to confirm when the needle tip enters the epidural space. This procedure is highly dependent on skill and expertise, so it is useful to quantify the tissue resistance during insertion. Sensors are used to measure the force and displacement of the plunger of the syringe and the pressure at the needle tip. A model is also developed to estimate the pressure from the force and displacement. Tests are first performed on porcine tissue to compare the continuous-pressure and intermittent-pressure versions of the technique and to compare the paramedian and midline needle approaches. The accuracy of the pressure model is 12% of peak pressure for the continuous technique and 20% for the intermittent technique. Significant differences in injection flow rate were also found for the muscle, interspinous ligament, and ligamentum flavum encountered in the two approaches. A small clinical study on human subjects was performed and again significant differences were found in flow rate for different tissues. These quantitative results improve the understanding of small differences in feel that have been previously known qualitatively and may help in the development of simulators.
硬膜外麻醉是产科最常见的麻醉方式。通过向盐水中注射时阻力的消失来确认针尖何时进入硬膜外腔。此操作高度依赖技巧和专业知识，因此在穿刺过程中对组织阻力进行量化很有用。传感器用于测量注射器活塞的力和位移以及针尖处的压力。还开发了一个模型，用于根据力和位移估算压力。首先在猪组织上进行测试，以比较该技术的连续压力和间歇压力版本，并比较旁正中进针法和中线进针法。对于连续技术，压力模型的准确度为峰值压力的12%，对于间歇技术为20%。在两种进针法中遇到的肌肉、棘间韧带和黄韧带的注射流速也存在显著差异。对人体受试者进行了一项小型临床研究，不同组织的流速再次出现显著差异。这些定量结果增进了对之前定性已知的细微手感差异的理解，并可能有助于模拟器的开发。
