Feed motion resection force analysis of 1 mm and 2 mm biopsy punches on tempered human cadaver skin use for the acquisition of full skin islets for skin transplantation

Abstract

Abstract:In this study we analysed the resection forces occurring when tempered human cadaver skin was punched with 1 mm and 2 mm biopsy punches as part of a project to develop a method for transplanting autologous whole skin on severely burned patients. The objective was to determine the force required to penetrate human skin with differently sized biopsy punches when resection was carried out by employing a simple forward motion without any rotation. To this end two different tests were performed with similar experimental setups. In the first test, the forces emanating from individual 1 mm and 2 mm biopsy punches were compared. For each punch size, 100 resection force curves were measured on four pieces of skin obtained from two donors. For the second test two bunch biopsy stamps were constructed, each of which contained a hundred punch biopsy cylinders. In one of the stamps the cylinders were all of the same length, while in the other they were all of a different length. It was also determined how many whole skin islets remained in the punches after the biopsy procedure, as well as the proportion of skin cylinders which could not be released from the original skin layer. The tests were performed using a Zwick material testing machine equipped with appropriate force sensors (i.e. load cells). The study revealed that the use of smaller diameter biopsy punches, as well as the use of punches with different length resection cylinders resulted in a reduction in the forces occurring upon resection. The measured resection forces were also so high that a combined forward and rotary movement of the punch proved more effective regarding the expenditure of force than a punching motion that merely involved a simple forward motion.