Blood-mimicking fluid using glycols aqueous solution and their physical properties

We present blood-mimicking fluids (BMFs) for the Doppler test object of medical ultrasound diagnostic instruments. Each of the acoustic velocity, density, and viscosity defined in the International Electrotechnical Commission (IEC) standard is given as a constant value. However, the viscosity of human blood depends greatly on the shear rate of the blood. In accurate studies using a specified flow phantom, therefore, the BMFs with the appropriate viscosity are required. To formulate fluids with the viscosity ranging from 4 to 30 mPas, we have developed a new fluid made of glycols and water-soluble silicone oil. We have used ethylene glycol, diethylene glycol, triechylene glycol, and poly(ethylene glycol) for the fluid. The glycols have different viscosities depending on their molecular weight and their acoustic velocity and density are almost the same. By selecting the glycol with the optimum molecular weight, the viscosity of the fluid could be set at the desired value and the acoustic properties of this fluid satisfied the values of the acoustic velocity and density defined by the IEC standard.