| Summary: | 碩士 === 義守大學 === 生物醫學工程學系 === 107 === Improper ultrasound propagation produces reflection waves. When the impedance at signal source is not the same as the impedance at the load side it will produce reflection waves.
The smaller the reflection wave, the more ultrasound power tissues or cells receive during ultrasound treatment.
The initial version of the power meter uses the MAX2016 IC as the main power sensor, this IC input range is for high frequencies. After testing its function and accuracy, we performed a series of experiments as shown in the results.
The target of this study is to design a power meter for use in low frequency ultrasound stimulation of cells and tissues. The ultrasound signal has low frequency which is around 28 kHz, so we select the HMC612 IC to design another power meter for low frequency.
The designed power meter contains a PCB and a bi-directional coupler, the MAX2016 and HMC612 IC can detect the forward and reverse signals during ultrasound treatment. Knowing the exact values of the forward and reverse signals allows for adjustment so that reflections can be minimized.
Finally, a commercial ultrasound power meter was compared with the MAX2016 and HMC612 based power meters to confirm that they have similar characteristic. The system was also connected to an Arduino board so that the user can read the power values on an LCD display.
|
|---|
