摘要:
The current invention provides an ultrasound-assisted delivery device, that includes a focused ultrasound transducer having an ultrasound focal point, a real-time imaging device having an imaging focal point, and a therapeutic delivery device, where the transducer and the imaging device are integrated with the delivery device, and the ultrasound focal point coincides with the imaging focal point, where the delivery device and transducer are disposed to provide an unobstructed imaging path for the real-time imaging device. The invention further includes a scanning optical or laser beam having a focal point disposed to sweep across the target, where the delivery device is disposed to deliver an optical contrast material to the target, and the scanning focal point coincides with the ultrasound and imaging focal points, where the target or the optical contrast material react to the scanning beam to generate at least one interface signal.
摘要:
Surface selective photoacoustic (PA) medical imaging is introduced. Surface selective PA imaging is responsive to surface features and does not image sub-surface features, in contrast to conventional PA imaging. The surface PA signal can be considerably larger than the bulk PA signal, for an air-coupled (or gas-coupled) acoustic transducer. Distinguishing these two signals based on time of arrival at the transducer can further distinguish the two signals. This approach provides numerous advantages. Non-contact imaging simplifies and expedites imaging, and can serve as a replacement for visual inspection by physicians. Applications include skin screening and endoscopy.
摘要:
A capacitive micromachined ultrasonic transducer (CMUT) array connected to a separate electronic unit is provided. The CMUT array includes at least two active elements, a ground element at the array end, and a non-active element having isolation trenches disposed between the active and ground elements. The active element includes a doped first silicon layer, a doped second silicon layer, and a first insulating layer disposed there between. A cavity is in the first silicon layer having a cross section that includes vertical portions disposed at each end of a horizontal portion, and the vertical portion spans from the first insulating layer through the first silicon layer such that a portion of the first silicon layer is isolated by the first insulating layer and the cavity. A membrane layer on the first silicon layer spans the cavity. A bottom electrode is disposed on the bottom of the second silicon layer.
摘要:
A reduced crosstalk capacitive micromachined ultrasonic transducer (CMUT) array is provided. The CMUT array has at least two CMUT array elements deposited on a substrate, at least one CMUT cell in the array element, a separation region between adjacent CMUT array elements, and a membrane formed in the separation region. The membrane reduces crosstalk between adjacent array elements, where the crosstalk is a dispersive guided mode of an ultrasonic signal from the CMUT propagating in a fluid-solid interface of the CMUT array. Each cell has an insulation layer deposited to the substrate. A cell membrane layer is deposited to the insulation layer, where the cell membrane layer has a vacuum gap therein. The cells further have an electrode layer deposited to a portion of the membrane layer, and a passivation layer deposited to the electrode layer, the cell membrane layer and to the insulation layer.
摘要:
Peak blood velocity measurement for automated stenosis detection is provided. Ultrasound measurements of the peak blood velocity are corrected by a calculation of the Doppler angle, which exists from misalignment of the ultrasound transducer axis and the true blood velocity. The direction of the blood velocity and the Doppler angle are found by imaging a set of planar cross-sections of a blood vessel, such as the carotid artery, to obtain velocity maps of the blood flowing in the blood vessel. Peak blood velocity can be correlated with an amount of stenosis therefore accurate peak blood velocity measurements are necessary for medical diagnosis. Automated stenosis detection allows for implementation in many medical settings. A capacitive micromachined ultrasound transducer array is also provided to measure the planar cross-sectional images.
摘要:
A high temperature micromachined ultrasonic transducer (HTCMUT) is provided. The HTCMUT includes a silicon on insulator (SOI) substrate having a doped first silicon layer, a doped second silicon layer, and a first insulating layer disposed between the first and second silicon layers. A cavity is disposed in the first silicon layer, where a cross section of the cavity includes a horizontal cavity portion on top of vertical cavity portions disposed at each end of the horizontal cavity portion, and the vertical cavity portion spans from the first insulating layer through the first silicon layer, such that a portion of the first silicon layer is isolated by the first insulating layer and the cavity. A membrane layer is disposed on the first silicon layer top surface, and spans across the cavity. A bottom electrode is disposed on the bottom of the second silicon layer.
摘要:
A reduced crosstalk capacitive micromachined ultrasonic transducer (CMUT) array is provided. The CMUT array has at least two CMUT array elements deposited on a substrate, at least one CMUT cell in the array element, a separation region between adjacent CMUT array elements, and a membrane formed in the separation region. The membrane reduces crosstalk between adjacent array elements, where the crosstalk is a dispersive guided mode of an ultrasonic signal from the CMUT propagating in a fluid-solid interface of the CMUT array. Each cell has an insulation layer deposited to the substrate. A cell membrane layer is deposited to the insulation layer, where the cell membrane layer has a vacuum gap therein. The cells further have an electrode layer deposited to a portion of the membrane layer, and a passivation layer deposited to the electrode layer, the cell membrane layer and to the insulation layer.
摘要:
An apparatus and method are disclosed for characterizing semiconductor wafers or other test objects that can support acoustic waves. Source and receiving transducers are configured in various arrangements to respectively excite and detect acoustic waves (e.g., Lamb waves) in a wafer to be characterized. Signals representing the detected waves are digitally processed and used to compute a measurement set correlated with the waves' velocity in the wafer. A characterization sensitivity is provided that describes how different wafer characteristics of interest vary with changes in the propagation of the acoustic waves. Using the characterization sensitivity and measurement sets computed at a setup time when all wafer characteristics are known and one or more process times when at least one of the characteristics is not known the perturbation in wafer characteristics between the setup and the process times can be determined. Characterization accuracy is improved by a wafer calibration procedure wherein measurement offsets from known conditions are determined for each wafer being characterized. An apparatus and technique are disclosed for correcting for anisotropy of acoustic wave velocity due to the direction of wave propagation with respect to a preferred crystallographic axis of the wafer. An apparatus and technique are also described for measuring wafer temperature using a single transducer whose temperature is related to the temperature of the wafer and, optionally, resonator structures. For characterization steps that occur when the wafer is chucked, a chuck structure is described that reduces the likelihood of the chuck interfering with the waves in the wafer.
摘要:
A liquid level control structure and a method for its production. The controller is comprised of a plate having substantially flat top and bottom surfaces and an hourglass-shaped aperture containing a marking fluid. Protruding a known amount and at a known angle from opposite sides of the aperture waist are knife-edged lips that interact with the fluid's surface tension to control the location of an unbounded surface of the fluid.The method for producing the liquid level control structure uses semiconductor fabrication techniques. The aperture is formed in a semiconductor wafer using several etching steps, some of which act along the crystalline planes of the wafer. The lips are formed from etch stop layers deposited between etching steps, while the knife-edges are formed on the ends of the lips during an etching step. Beneficially, the location of the knife-edges relative to one surface of the wafer is independent of small variations in the thickness of the water.
摘要:
The free ink surface levels of acoustic ink printers are controlled by cap structures that have substantially non-retroreflective aperture configurations. The non-retroreflective configurations of the apertures of these cap structures cause diffusive scattering or directional deflection of the reflected surface ripple waves, thereby significantly reducing the time that is required for the oscillatory perturbations, which are caused by reflection of the surface ripple waves that are generated during the droplet ejection process, to dissipate to a negligibly low amplitude in the critical local areas of the ejection sites. This, in turn, increases the droplet ejection rates at which printers having such cap structures can be operated asynchronously.