The Ergonomics Of Syringe Operation During The Injection Of Fluid Into Tissue Expanders

The reconstruction process following a mastectomy procedure may require the use of a tissue expander(s) to accommodate an implant. Over several months, the expanders are routinely filled with sterile saline solution to gradually stretch the skin and muscle around the subpectoral pocket. The saline solution is injected manually by the surgeon or nurse into the expander using a syringe, catheter and needle. The injection process is physically demanding and repetitive; it has been reported to pose negative long-term effects on the muscles and joints of the hand, causing repetitive strain injuries for the syringe operator. Thus, the purpose of this study is to analyze the injection process and provide a comprehensive understanding of the factors that can be intervened upon to make this process more ergonomic and safe. To achieve this understanding, a laboratory testing setup is developed to mechanically simulate and analyze the fluid injection process into tissue expanders. Experimental results show that the magnitude of the syringe force required to inject the fluid is significantly correlated to the rate of compression, the size of the syringe and the resistance produced by the stretching of tissue expander. Moreover, the magnitude of forces measured during testing are found to be well above the recommended values to prevent repetitive stress injuries.