Hardware Platform Design Of Coagulation Detection System Based On Magnetoelastic Sensors

Coagulation is an important indicator of blood system function.The abnormality of coagulation function will lead to many diseases,such as hemophilia and stroke.In clinical practice,the patient’s coagulation function will often need to be known in advance,particularly for anticoagulant therapy and surgery..The traditional detection methods of coagulation include optical method,solidification method and dry chemical method,etc..Although they are well establish and the relevant detection instruments are also highly automated,they have the disadvantages of high cost and inconvenient operation.In contrast,the magnetoelastic sensor,as a miniaturized,new sensor,which can reflect the change in viscosity,quality,stress and other parameters by detecting the resonance characteristics,is greatly advantageous in this respect.Moreover,our preliminary study and reports for other research groups both at home and abroad have already confirmed the feasibility of applying the magnetoelastic sensor to detect coagulation function,as well as its advantages of simple structure and high sensitivity.Therefore,the coagulation detection technology based on magnetoelastic sensors has broad application prospects.In this thesis,according to the requirements of coagulation detection,a hardware platform based on magnetoelastic sensors was designed with the impedance detection method.The platform was made up of the hardware and the lower computer software.The hardware design included an MCU,a solenoid coil,a blood viscosity detection circuit,a temperature controller and a detection chip.In more detail,the Blood viscosity detection circuit design involved AC excitation,DC excitation,phase detection and amplitude detection.The lower computer software design included the control of detection circuit,the communication with the host computer and temperature control based on the PID algorithm.The functional test of the system platform was carried out by using the magnetoelastic sensors made of the Fe-based amorphous alloy strip 1K101.Both the repeated tests and the resonance response tests were completed under the condition of air and different concentrations of glycerol solution.Then the blood coagulation measurement experiments followed,including the quality control tests and adult blood tests.The original experimental data was compared with those obtained from a TEG5000 coagulation device which was produced by Haemoscope company.The results indicate that that the dynamic detection of the change in blood viscosity during the coagulation process is realized successfully by the use of magnetoelastic sensors,and the their dynamic responses to the coagulation time,coagulation speed are similar to those of the TEC5000 device.