Martin K, Fernandez R
Medical Physics Department, Leicester Royal Infirmary NHS Trust, UK.
Ultrasound Med Biol. 1997;23(8):1267-74. doi: 10.1016/s0301-5629(97)00109-9.
Acoustic beam nonuniformities are not uncommon in physiotherapy ultrasound equipment and can lead to errors in delivered dose. A relatively simple thermal technique is described for mapping the intensity distribution in physiotherapy ultrasound beams that could be used for routine QA checks. The technique uses a thermochromic material sandwiched between layers that absorb ultrasound. The structure is used in a water bath to intersect the ultrasound beam. Thermal models predict that, with suitable absorbing materials and careful control of the surface temperature of the layers, sufficient spatial resolution and sensitivity can be achieved to show the intensity distribution in physiotherapy ultrasound beams. Thermal images of sections through physiotherapy ultrasound beams using this method correlate well with corresponding intensity maps generated by planar scanning with a hydrophone.
声束不均匀性在物理治疗超声设备中并不罕见，并且可能导致输送剂量出现误差。本文描述了一种相对简单的热学技术，用于绘制物理治疗超声束中的强度分布，该技术可用于常规质量保证检查。该技术使用夹在吸收超声的层之间的热致变色材料。该结构用于水浴中与超声束相交。热模型预测，使用合适的吸收材料并仔细控制各层的表面温度，可以实现足够的空间分辨率和灵敏度，以显示物理治疗超声束中的强度分布。使用这种方法获得的物理治疗超声束截面的热图像与用水听器进行平面扫描生成的相应强度图具有良好的相关性。
