Laboratory Analysis of Force Required to Fill a Syringe

Abstract

Nurses routinely withdraw fluid from the stomachs of intensive care patients who are being provided nutrition intravenously in order to determine if the patient is properly tolerating the liquid nutrition. This is a critical measurement in patient care. If too little liquid nutrition is being provided, the patient will not follow a path of optimal healing. If too much liquid is being provided, the patient may have issues with the esophagus or have fluid get into the lungs, leading to pneumonia. The purpose of this work is to conduct a laboratory study to investigate the process of drawing fluid through a syringe in an environmentally-controlled laboratory. A force measurement system is used that includes the ability to control the displacement and speed of the syringe pump. Additionally, laboratory data from the force measurement system are presented for different tube materials, different tube diameters, and different fluids with varying viscosity. Viscosity is also determined by using a falling-ball viscosimeter test in the lab. The force required to withdraw fluid for each of these variables is studied. The amount of fluid withdrawn for each combination of variables is recorded in light of attempting to provide guidance to nurses and other health care providers about the best way to obtain the required data and keep patients healthy.