Development of a Micro-Volume Viscometer for Blood Viscosity Measurements based on Micro-Particle Image Velocimetry (μPIV)

Abstract

Whole Blood viscosity can provide plenty of pathological information such as hypertension multiple myeloma diabetes and so forth Conventionally both capillary viscometers and rotary viscometers are most widely used in the clinical practices However capillary viscometers are easy to incur human errors while rotary viscometers are limited to working ranges causing difficulty and hassle in cross-scale measurements In addition both instruments are sample consuming and wasteful To solve the problems a micro-volume viscosity measurement technique based on micro particle image velocimetry (μPIV) was therefore developed in this thesis Generally fluids can be divided into Newtonian and Non-Newtonian fluids based on viscosity The viscosity of Newtonian fluid changes with the shear rate; whereas that of Non-Newtonian fluid varies with the shear rate Accordingly the whole blood is considered as Non-Newtonian fluid and should be carefully characterized Brownian motion is known as random movement of particles suspended in a fluid The relationship between the random movement and the liquid viscosity can be expressed by the Stoke-Einstein equation In this thesis the relationship was systematically investigated using the μPIV diffusometry The liquid viscosity was eventually obtained by quantifying the Brownian motion of suspended particles dispersed in a medium The technique was characterized by water-based solutions in dynamic and static measurement conditions According to this technique less than 2 μL samples are required in a static measurement and a broad viscosity range (0 5-1000 mPa‧s) can be measured Although the relationships between the whole blood viscosity and diseases (diabetes hypertension multiple myeloma and cancer) which receive less attention nowadays the whole blood viscosity with different hematocrit can already be measured statically by this technique The image based micro-volume viscometer can provide valuable information in cardiovascular diagnostics is expected

Date of Award	2014 Sept 2
Original language	English
Supervisor	Han-Sheng Chuang (Supervisor)