Ultrasonic applicator with direct acoustical coupling for interstitial heating

在本提案中，我们提出了一种可能对治疗目的的组织加热有用的装置。为此，提议的设备将超声波直接沉积到组织中。超声能量与周围体积相互作用转化为热量。目前有类似原理的设备，但这些设备是将超声波从组织外部源转移到组织中。大多数现有的设备使用聚焦超声光束，直接指向异常组织。它们将异常组织的温度升高到一个高值，从而导致异常细胞死亡。如果异常细胞位于骨骼结构（如颅骨）后面或周围，或位于充满气体的器官（如肺）后面，则使用上述方法有困难。在这种情况下，超声波必须直接沉积到有异常细胞的体积中。我们已经研制出一种能够直接沉积超声波的设备。然而，我们发现这个设备相当复杂和笨重。这是它的严重局限性。我们还注意到，使用它需要对其操作原理有很好的理解，因此它只适用于非常熟练的操作员。为了使设备对治疗有用，它必须易于由具有典型技术和/或科学能力的人员操作。我们认为建议的仪器满足上述要求。我们还认为，在开发新设备中获得的经验可能会对从事生物医学超声工作的其他研究人员有所帮助。

In this proposal, we offer to develop a device that may be useful for heating in tissues with therapeutic goal.  For that purpose, the proposed device will deposit ultrasound directly into the tissue.  Ultrasound energy on interaction with the surrounding volume is converted into heat.  Currently there are devices that work on similar principle, but with these devices ultrasound is transferred into the tissue from a source external to the tissue.  Majority of the existing devices use focused ultrasound beams that are directed towards abnormal tissue.  They raise the temperature of the abnormal tissue to a high value which leads to abnormal cells death.  There are difficulties in using the above procedure if the abnormal cells are behind or around boney structures, e.g., skull or behind organs filled with gases, e.g., lungs.  In case like that ultrasound must be deposited directly into the volume with abnormal cells.        We have already worked on a device capable of direct deposition of ultrasound.  We found, however, that the device was quite complicated and bulky.  That has been its serious limitation.  We noticed also that its use required very good understanding of its principle of operation and thus it worked only for very skillful operators.  For the device to be useful for therapy, it must be easy to operate by personnel with typical technical and/or scientific abilities.  We believe that the proposed instrumentation satisfies the above requirements. We think also that experience gained in development of the new device may be helpful to other researchers who work in biomedical ultrasound.