A New Scatter Particle and Mixture Fluid for Preparing Blood Mimicking Fluid for Wall-Less Flow Phantom.

Background: To examine the blood flow and detection of the issues related to it by medical ultrasound, it is extremely important to have suitable blood mimicking fluid (BMF) to be used in vitro and to have a movable or portable Doppler flow phantom to use it as a standardizing tool. As known, the main drawbacks of the currently commercial BMF used in the research studies are high in cost and the long time needed for preparation, which is at least 5-7 h. Moreover, there are only two common scatter particles using in BMF as suspension materials such as nylon (Orgasol) and polystyrene. Thus, we need to prepare BMF with both a new mixture fluid and new scatter particle to be as a reflecting factor of ultrasonic waves, for evaluating the speed of sound of the blood flow in the same method like in the research study of ultrasound with relatively low-cost and less consuming time of preparation. However, both the acoustical and physical features of the Doppler flow phantom components (BMF and tissue mimicking material) must correspond the features of the human tissues to make the examination significance. In addition, the BMF must also represent the hemodynamic features of real human blood.

Methods: In this experiment, a new adequate ternary mixture liquid for preparation of BMF applied and suspended with a new scatter particle material, this scatter particle material called poly (4-methylstyrene), it used to be adequate with the mixture density and for saving neutrally buoyant. This BMF was prepared for use in the test objects or Doppler flow phantom. The poly (4-methylstyrene) particles were applied for suspension in a mixture liquid or fluid based on three items, which were distilled water, propylene glycol (PG), and polyethylene glycol (PEG) (200 Mw). The diameter of poly (4-methylstyrene) particles is 3-8 μm, which determined by specific sieve in a unit of μm, and the density is 1.040 g/ml.

Results: Speed of sound, viscosity, density, Backscatter power and attenuation features of mixture fluid or liquid which used for preparing a BMF were measured, discussed, and agreed with draft International Electrotechnical Commission values.

Conclusions: There are three various types of ternary items of mixture fluid (water, PG, and PEG [200 Mw]), and a new type of scatter particle material poly (4-methylstyrene) was utilized for preparing the BMF. The scatter particles and mixture fluid prepared and measured at a temperature that simulates the body temperature 37°C. Moreover, one of the advantages of this new blood that is being cheaper than the commercially available BMF products because the PG and the polyethylene glycol (200 Mw) are much cheaper and more available than glycerol and the Dextran that used usually. In addition, new BMF needs less time for preparation compared to the commercial one.