Abstract: The present invention describes systems and methods for creating a virtual force field. A field source may be scanned over a region of interest on an object using a scanning technique such as vector scanning or raster scanning. The techniques disclosed herein describe applying the force field over volumetric (spatial) regions that can extend beyond the dimensions of the focal region of the force-field source (e.g., acoustic, electromagnetic, or optical source). The present invention may equally apply to multiple processes linked by cause and effect that exhibit unequal time dependence.

Abstract: Methods are provided for enhancing the image of brachytherapy seeds implanted in tissue using a transrectal ultrasound apparatus. In a first arrangement the resonance of the seeds is determined and the seeds are insonified using acoustic signals having a resonance frequency of the seeds to cause the seeds to vibrate. The vibrating seeds have enhanced detection using a Doppler ultrasound device. In a second arrangement the acoustic signature of the seeds is determined and used to enhance the imaging of the seeds using a correlation function. In a third arrangement images are taken of the tissue and implanted seeds prior to and during the application of mechanical stress to the tissue. A correlation between the unstressed and stressed tissue can cause enhanced imaging of the seeds.

Abstract: Methods are provided for enhancing the image of brachytherapy seeds implanted in tissue using a transrectal ultrasound apparatus. In a first arrangement the resonance of the seeds is determined and the seeds are insonified using acoustic signals having a resonance frequency of the seeds to cause the seeds to vibrate. The vibrating seeds have enhanced detection using a Doppler ultrasound device. In a second arrangement the acoustic signature of the seeds is determined and used to enhance the imaging of the seeds using a correlation function. In a third arrangement images are taken of the tissue and implanted seeds prior to and during the application of mechanical stress to the tissue. A correlation between the unstressed and stressed tissue can cause enhanced imaging of the seeds.

Abstract: Improved methods of signal processing for generating estimates of tissue strain are presented. These techniques generally employ the frequency shifting of post-compression spectral data to determine a scaling factor which approximates the applied tissue strain. The scaling factor can be determined by finding the maximum correlation between the frequency shifted post-compression data to the pre-compression data and can also be determined by minimizing the variance of the ratio of such data. Correlation tracking and maximum correlation magnitude techniques for improving the results of elastography are also presented.

Abstract: Radiation pulses from a high energy therapeutic ultrasound system are used to stimulate tissue motion by radiation pressure. The tissue motion is monitored using a diagnostic ultrasound system.

Abstract: An apparatus for ultrasonic elastography includes a housing, a moveable surface, and a transducer in ultrasonic communication with the moveable surface. A driver is arranged to mechanically move the moveable surface with respect to the housing. The housing can also be formed such that the moveable surface is a moveable exterior surface of the housing, such as a compliant membrane, which is moved in response to the driver to induce tissue compression. The housing may be arranged to be held in an operator's hand. Alternatively, the housing may be arranged for an insertion into an opening in a patient's body. The driver may move the transducer or moveable exterior surface in a cyclical manner at a low frequency.

Abstract: Abstract of the Disclosure Improved methods of signal processing for generating estimates of tissue strain are presented. These techniques generally employ the frequency shifting of post-compression spectral data to determine a scaling factor which approximates the applied tissue strain. The scaling factor can be determined by finding the maximum correlation between the frequency shifted post-compression data to the pre-compression data and can also be determined by minimizing the variance of the ratio of such data. Correlation tracking and maximum correlation magnitude techniques for improving the results of elastography are also presented.