Dynamic analysis of surgical incision in head and neck surgery by using force sensing knife

1. 在外科手术中，皮肤切开是一项基本技术。然而，质量、方法、技术和切口深度通常是经验评价。关于刀在切开过程中所受的力及其对组织和器官的动态影响的科学分析很少。在进行手术切口过程的动态分析之前，我们准备了1)一把带有双轴力传感器的刀，可以测量两个方向的力；2)一个双轴张力测量系统，可以评估切口过程中施加在皮肤上的张力。然后我们使用传感器刀对手术切口进行了动态分析。利用平行金属板在机械力作用下将应力转化为电流的原理，制备了传感器刀和皮肤张力传感器，实现了对力的检测。我们把这样一个传感器装在刀和张力计上。结果1)采用传感器刀和张力传感器对牛小腿进行切开。一个切口平行于肌纤维，另一个垂直于肌纤维。发现平行切口所需的力比垂直切口所需的力小。2)当在切口上施加张力时，切割所需的力比没有张力时要小。3)开始切口时，施加垂直力。随着切口的进行，施加的水平力几乎等于垂直力。4)对于临床头颈部手术时的皮肤切口，本研究结果提示，通过拇指和食指对皮肤施加的张力应该几乎相等。5)切开时，刀上的初始垂直力增大，然后水平力增大。发现皮肤的切口力大于脂肪组织的切口力。

1. Objectives of the studyIn surgery, making the skin incision is a basic technique. However, the quality, methods, techniques, and depth of incision are usually evaluated empirically. There has been little scientific analysis of the force applied to the knife during incision and its dynamic effect on the tissues and organs. Before performing a dynamic analysis of the process of surgical incision, we prepared 1) a knife with a biaxial force sensor that measured the force in two directions and 2) a biaxial tension measurement system that could assess the tension applied to the skin during incision. We then carried out a dynamic analysis of surgical incision using the sensor knife.2. Preparation of the biaxial sensor knife and biaxial skin tension sensorThe sensor knife and the skin tension sensor were prepared utilizing the principle that a parallel metal plate subjected to mechanical force converts the stress to electric current, enabling detection of the force. We attached such a sensor to a knife and tension meter.3. Results1) Incision was performed in a shank of beef using the sensor knife and tension sensor. One incision was made parallel to the muscle fibers and one was made perpendicular to the fibers. It was found that the parallel incision required less force than the perpendicular incision.2) When tension was applied across the incision, less force was needed for cutting than without tension.3) When starting the incision, vertical force was applied. As the incision proceeded, horizontal force was applied that was almost equivalent to the vertical force.4) For clinical skin incision during head and neck surgery, the results of this study suggest that the tension applied to the skin via the thumb and index finger should be almost equal.5) When making an incision, the initial vertical force on the knife was increased and then the horizontal force was increased. It was found that the incision force was greater for the skin than for adipose tissue.