Development Of The Surgical-procedure And Epidermal Vascular Ultrasound Doppler Flow Meter

Objective Since the development of Doppler flowmeter, many new products have some new characteristics, for example, ultrasound transmitter signal is small, need to stick to the vessel surface acoustic window measurements. It has some differences with previous products. Then there is no standard to require this function verification. We have already had some corresponding test phantoms for the methods of the existing standard. But above test phantoms have limitations so that can’t meet effectively the new testing requirements like the surgical-procedure ultrasound Doppler flow meter and epidermal vascular ultrasound Doppler flow meter. So it is necessary to develop a system which can use by the surgical-procedure ultrasound Doppler flow meter(the smaller ultrasound signal) and epidermal vascular ultrasound Doppler flow meter(measured on the vessel surface). The system can adjust the distance between simulated blood vessels with ultrasound probe to remove the attenuation of the ultrasonic signal. The system may measure not only smaller signal, but also flow and velocity.Method Researched the ultrasound characteristics of the blood and the existing blood flow phantoms, we may select the appropriate materials and components to complete the system which can use by the surgical-procedure ultrasound Doppler flow meter(the smaller ultrasound signal) and epidermal vascular ultrasound Doppler flow meter(measured on the vessel surface). It may be operated easy to set up the flow rate through the LCD touch screen and immerse the simulate vessel in a liquid. It has two passages which controlled by electromagnetic valve include a dedicated passage which make the simulate blood reach the simulate vessel without buffer container. The system may measure not only smaller signal,but also flow and velocity. Then the system may be tested and verified in order to meet the actual requirements. Finally, it may be prepared the specification and operating procedures to improve management program.Result The control system includes an LCD touch screen, a SCM control board, a driver board and a peristaltic pump. LCD touch screen is used to display operating status and input setting parameters. SCM control board controls the peristaltic pump. Fluid pipeline includes simulate blood, simulate vessels, liquid line pipes, a 3-way electromagnetic valve, a fluid container, a buffer container and a flume. There are four kinds of simulate vessel which the inner diameter are 1mm, 2mm, 3mm, 4mm.LCD touch screen has the main interface, system information, calibration interface and running interface. In the calibration interface can be calibrated flow or velocity. Number 1,2, 3, 4 simulate vessels can be calibrated flow individually. In the running interface It can be selected a constant flow mode or a pulse mode, and then set up the flow rate of the No. 1,2, 3, 4 simulate vessels.The simulate vessels of the existing blood flow phantom are in the simulate organization. It is difficult to test and verify for the surgical-procedure and epidermal vascular ultrasound Doppler flow meter. While this system is easy to do that because of immersing the simulate vessel in a liquid.The existing blood flow phantom is manual adjustment to achieve the desired flow rate. While this system may be operated easy to set up the flow rate through the LCD touch screen. The existing blood flow phantom has a buffer container so that the imitating the pulse of the pulse signal will be weakened. The system has two pathways. The simulate blood will flow past the buffer container in the constant flow mode and flow past the simulate vessels without the buffer container in the pulse mode. Two modes will be chose by the electromagnetic valve.Conclusion It has study the linear correlation by measuring and calculation. The pump speed has a linear correlation with the flow by measured the flow speed in the some case.Four kinds of simulate vessel, The maximum velocity of Four kinds of simulate vessel showed a linear correlation with the pump speed. But it may be reduce in a high speed(300-360 r / min). It may show the linear correlation with the flow by measured the flow speed in a little results of measuring. It is some complex and difficult to simple physical models to simulate. It may show some deviations between the results of maximum velocity and average velocity and U_max=2U_mean.