Development Of A Hand-held Doppler For Vascular Assessment And FHR Detection

The increasingly accelerated pace of life and unhealthy habits lead to theepidemic of chronic diseases in modern society. Many chronic diseases tend to haveclose correlation and often have common complications, such as cardiovascularevents, stroke and diabetes which all can cause peripheral arterial vascular disease. Sothe peripheral hemodynamic parameters can reflect the physiological state of humanbody, and can be used as an important index of chronic diseases in the clinicaldiagnosis, and also can help to carry out effective chronic diseases management.As the regional differences in health care services, we need to have medicalequipments characterized by easy to promote in the community or family, portable,easy to operate, no harm, low cost and having the ability of remote communication.The objective of this topic is to develop a portable Doppler device with the functionsof data collection, data storage, data transmission, data display and voice-assisteddiagnostic for community and home applications. In order to fully utilize the systemresources and considering the practical significance of daily fetal heart rate (FHR)monitoring, the device can measure the FHR in addition to the function of measuringblood flow, so that the device can also be used for fetal monitoring to play a greaterperformance. The issue is part of the research and development of new equipment formajor chronic disease screening and monitoring (NO:2012BAI19B00) of theNational Science and Technology Support Program.The device is based on the principle of Doppler Effect, and uses STM32microprocessor as the core. The system acquires fetal heartbeat frequency offset bycoherent demodulation method and acquires blood flow frequency offset bydirectional orthogonal phase demodulation method. The system consists of probemodule, power supply module, data acquisition module, USB module, key module,data storage module, audio processing module, LCD module, network transceivermodule and PC to realize the functions of data acquisition, data storage, datatransmission, issuing the sound of blood flow and fetal heartbeat, display pulse rate orFHR or bi-directional wave of blood flow in real time. The issue mainly includesthree aspects: the system’s hardware design, the system’s software design and the testof the system.According to the test of the system, the system can achieve the functions of patient’s flow data or fetal heartbeat data collection, data processing, data storage, datatransmission, issuing the sound of blood flow and fetal heartbeat, display pulse rate orFHR or bi-directional wave of blood flow in real time, and it can be used for thedetection of abnormal blood flow and FHR. The device is portable and easy to use,and is applicable to primary health care units and home care.