Design and Manufacture of Polyvinyl Chloride (PVC) Tissue Mimicking Material for Needle Insertion

Abstract

The polyvinyl chloride (PVC) tissue-mimicking material for needle insertion was manufactured and evaluated. Factorial design of experiment was conducted by changing three factors - the ratio of softener and PVC polymer solution, the mass fraction of mineral oil, and the mass fraction of micro-sized glass beads - to study the indentation hardness, compression elastic modulus and friction and cutting forces in needle insertion of 12 types of soft PVC material. The indentation hardness of the soft PVC material ranged from 5 to 50. The elastic modulus of the soft PVC material was from 6 to 45 kPa between 0-0.15 strain. The friction and cutting force during needle insertion also had large ranges, which were from 0.005 to 0.086 N/mm and 0.04 to 0.36 N respectively. The analysis of variance showed that the ratio of softener and PVC polymer solution had the most significant effect on all of the four properties of the PVC material. The percentage of mineral oil also had statistical significance on these four properties. The glass beads only had effect on the needle insertion cutting force. A nonlinear regression model was applied to find relationships among mechanical properties and the significant factors. The R2 values of the regression analysis results were all larger than 0.9. Four properties of a PVC tissue-mimicking material can be designed to desired values based on these relationships.