Patent application number | Description | Published |
20080221448 | Image-guided delivery of therapeutic tools duing minimally invasive surgeries and interventions - Imaged-guided therapy for minimally invasive surgeries and interventions is provided. An image-guided device includes an elongate tubular member, such as a catheter, an annular array of capacitive micromachined ultrasound transducers (cMUTs) for real-time three-dimensional forward-looking acoustic imaging, and a therapeutic tool. The therapeutic tool is positioned inside an inner lumen of the elongate tubular member and can be a device for tissue ablation, such as a high intensity focused ultrasound (HIFU) device or a laser. The HIFU device is operable at high frequencies to have a sufficiently small focus spot, thus a high focal intensity. The imaging annular array is also operable at high frequencies for good acoustic imaging resolution. The high resolution forward-looking imaging array, in combination with the high frequency HIFU transducer, provides a single image-guided therapy device for precise tissue ablation and real-time imaging feedback. | 09-11-2008 |
20080259725 | Acoustic crosstalk reduction for capacitive micromachined ultrasonic transducers in immersion - 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. | 10-23-2008 |
20090122651 | Direct wafer bonded 2-D CUMT array - 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. | 05-14-2009 |
20090140357 | High-temperature electrostatic transducers and fabrication method - 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. | 06-04-2009 |
20090142872 | Fabrication of capacitive micromachined ultrasonic transducers by local oxidation - Fabrication methods for capacitive micromachined ultrasonic transducers (CMUTS) with independent and precise gap and post thickness control are provided. The fabrication methods are based on local oxidation or local oxidation of silicon (LOCOS) to grow oxide posts. The process steps enable low surface roughness to be maintained to allow for direct wafer bonding of the membrane. In addition, methods for fabricating a step in a substrate are provided with reduced or minimal over-etch time by utilizing the nonlinearity of oxide growth. The fabrication methods of the present invention produce CMUTs with unmatched uniformity, low parasitic capacitance, and high breakdown voltage. | 06-04-2009 |
20090292208 | Automated detection of asymptomatic carotid stenosis - 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. | 11-26-2009 |
20090301550 | FOCUSED ACOUSTIC PRINTING OF PATTERNED PHOTOVOLTAIC MATERIALS - Photovoltaic material is printed on a substrate using acoustic printing, to produce solar cells. Acoustic printheads are configured to eject droplets of photovoltaic material to positions on the substrate, responsive to focused acoustic energy provided by acoustic ejectors in the acoustic printheads, to print a film of the photovoltaic material. A positioning system is configured to position the acoustic printheads with respect to the substrate. A feedback system controls the acoustic ejection of the droplets of photovoltaic material by the acoustic printheads or the positioning of the acoustic printheads with respect to the substrate by the positioning system, based on feedback data indicative of characteristics of the printed film. The acoustic printheads are designed optimally for printing of photovoltaic material for solar cells in single scans in only one direction of the substrate. Solar cells can be manufactured at low cost and with high throughput using acoustic printing. | 12-10-2009 |
20100152559 | APPARATUS AND METHOD FOR NON-INVASIVE AND MINIMALLY-INVASIVE SENSING OF PARAMETERS RELATING TO BLOOD - Medical diagnostic system, apparatus and methods are disclosed. Optical transmitters generate radiation-containing photons having a specific interaction with at least one target chromophore in a target structure, preferably a blood vessel such as the interior jugular vein. The optical transmitters transmit the radiation into at least a first area including a substantial portion of the target structure and into a second area not including a substantial portion of the target structure. Optical receivers detect a portion radiation scattered from at least the first area and the second area. A processor estimates oxygenation, pH or cardiac output based on the scattered radiation detected from the first area, and the scattered radiation from the second area. | 06-17-2010 |
20100152591 | APPARATUS AND METHOD FOR NON-INVASIVE AND MINIMALLY-INVASIVE SENSING OF PARAMETERS RELATING TO BLOOD - A system and method for monitoring one or more parameters relating to blood, such as cardiac output, of a patient is provided. The system preferably includes an acoustic energy transducer unit configured and positioned to transmit acoustic energy into a target structure, preferably a blood vessel, within the patient so as to induce a measurable change, preferably a change in blood volume, within the target structure. The transducer unit can be an ultrasonic array, annular array, or groups thereof, or a single element transducer. The unit can also be a vibrator or acoustic loudspeaker. An optical transmitter transmits light into the target structure, and an optical receiver senses light scattered from within the target structure. The blood parameter can then be estimated from the sensed scattered radiation. Relative blood oxygen saturation in the blood vessel can be estimated by transmitting two wavelengths to measure oxy-hemoglobin and deoxy-hemoglobin. | 06-17-2010 |
20100173437 | Method of fabricating CMUTs that generate low-frequency and high-intensity ultrasound - The present invention provides a method of fabricating low-frequency and high-intensity ultrasound CMUTs that includes using deep reactive ion (DRIE) etching to etch at least one cavity in a first surface of a conductive silicon wafer, growing an insulating layer on at least the first surface of the conductive silicon wafer, bonding a silicon layer of a SOI wafer to the insulating layer, where the SOI wafer includes a handle layer, a buried oxide layer and a conductive silicon layer. The handle layer and the buried oxide layer of the SOI wafer are removed, where the conductive layer of the SOI wafer forms a membrane across at least one cavity, and electrically isolating at least one the membrane across the at least one cavity, where at least one the low-frequency and high-intensity ultrasound CMUT is provided. | 07-08-2010 |
20100225200 | Monolithic integrated CMUTs fabricated by low-temperature wafer bonding - Low temperature wafer bonding (temperature of 450° C. or less) is employed to fabricate CMUTs on a wafer that already includes active electrical devices. The resulting structures are CMUT arrays integrated with active electronics by a low-temperature wafer bonding process. The use of a low-temperature process preserves the electronics during CMUT fabrication. With this approach, it is not necessary to make compromises in the CMUT or electronics designs, as is typical of the sacrificial release fabrication approach. Various disadvantages of sacrificial release, such as low process control, poor design flexibility, low reproducibility, and reduced performance are avoided with the present approach. With this approach, a CMUT array can be provided with per-cell electrodes connected to the substrate integrated circuitry. This enables complete flexibility in electronically assigning the CMUT cells to CMUT array elements. | 09-09-2010 |
20100268152 | Method and apparatus for ultrasound assisted local delivery of drugs and biomarkers - 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. | 10-21-2010 |
20110050033 | Micromachined ultrasonic transducer having compliant post structure - A compression post capacitive micromachined ultrasonic transducer (CMUT) is provided. The compression post CMUT includes a first electrode, a top conductive layer having a pattern of post holes, a moveable mass that includes the first electrode. The compression post CMUT further includes an operating gap disposed between the top surface of the top conductive layer and a bottom surface of the moveable mass, a pattern of compression posts, where a proximal end the compression post is connected perpendicularly to a bottom surface of the moveable mass, where the pattern of compression posts span through the pattern of post holes. The top conductive layer includes the second electrode that is electronically insulated from the first electrode, where the pattern of compression posts compress to provide a restoring force in a direction that is normal to the bottom surface of the moveable mass. | 03-03-2011 |
20120259249 | Noninvasive Ultrasound-Based Retinal Stimulator: Ultrasonic Eye - Focused ultrasound is a promising technology for neural stimulation that is non-invasive, and capable of passing through the skull. Here we use the isolated retina to characterize the effect of ultrasound on an intact neural circuit and compared these effects to those of visual stimulation of the same retinal ganglion cells. Ultrasound stimuli evoked precise, stable responses that looked qualitatively similar to strong visual responses but with shorter latency. We found that ultrasonic stimulation activates cells presynaptic to ganglion cells, which may include photoreceptors and interneurons. Ultrasonic stimulation is an effective and spatial-temporally precise method to activate the retina. Ultrasonic stimulation may have diagnostic potential to probe remaining retinal function in cases of photoreceptor degeneration, and therapeutic potential for use in a retinal prosthesis. In addition, ultrasound promises to be a useful tool to understand the dynamic activity in the interneuron population of the retina. | 10-11-2012 |
20130023752 | Medical Screening and Diagnostics Based on Air-Coupled Photoacoustics - 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. | 01-24-2013 |
20130087867 | Method for operating CMUTs under high and varying pressure - Capacitive micromachined ultrasonic transducers (CMUTs) in permanent contact mode are provided. Such a CMUT always has its plate in contact with the substrate, even for zero applied electrical bias. This contact is provided by the pressure difference between the environment, and the pressure of the evacuated region between the CMUT plate and substrate. Due to this permanent contact, the electric field in the gap for a given DC bias voltage will be larger, which provides improved coupling efficiency at lower DC bias voltages. Furthermore, in an environment with high and varying pressure, the plate will not shift between the conventional mode and the collapsed mode, but will only be pushed down with varying contact radius. In some embodiments, an electrode shaped as an annulus is employed, so that only the active vibrating part of the CMUT plate sees the applied DC and AC voltages. | 04-11-2013 |
20130088118 | Pre-charged CMUTs for zero-external-bias operation - Capacitive micromachined ultrasonic transducers (CMUTs) having a pre-charged floating electrode are provided. Such CMUTs can operate without an applied DC electrical bias. Charge can be provided to the floating electrode after or during fabrication in various ways, such as injection by an applied voltage, and injection by ion implantation. | 04-11-2013 |
20130245505 | Noninvasive Ultrasound-Based Retinal Stimulator: Ultrasonic Eye - A retinal stimulation and prosthetic device is provided that includes at least one ultrasonic transducer having a focused ultrasonic signal, where the focused ultrasonic signal includes an acoustic frequency, a spot size, a temporal pattern, a pulse duration and a power capable of stimulating retinal neurons when the at least one ultrasonic transducer is disposed proximal to an eye. | 09-19-2013 |
20140133279 | Energy Harvesting - As may be implemented in accordance with one or more embodiments, an apparatus and/or method involves a plurality of transducer elements that convert energy waves conveyed via a multi-directional radiation pattern into electrical charge. A power-accumulation circuit accumulates electrical charges from each of the plurality of transducer elements, with each of the transducer elements being arranged at different respective off-axis angles relative to an axis at which the energy is being conveyed. The power-accumulation circuit accumulates energy from each of the individual energy-transduction areas, such that energy received at different respective off-axis angles contributes to the accumulation of electrical charge. | 05-15-2014 |
20140239770 | Capacitive Micromachined Ultrasound Transducers with Pressurized Cavities - A capacitive micromachined ultrasonic transducer (CMUT) is provided that includes a substrate, a bottom conductive layer disposed on a bottom surface of the substrate, a cavity disposed into a top surface of the substrate, a nonconductive layer disposed on the substrate top surface and on the cavity, a CMUT plate disposed on the nonconductive layer and across the cavity, a top conductive layer disposed on a top surface of the CMUT plate, a pressure control via that spans from the cavity to an ambient environment, and an active pressure controller connected to the pressure control via, wherein the active pressure controller is capable of actively varying a pressure differential across the CMUT plate. | 08-28-2014 |
20140362013 | METHOD AND APPARATUS FOR SENSING TOUCH - Aspects of the present disclosure are directed towards methods, systems, and apparatuses that include a pressure-sensor arrangement including a plate structure and a plurality or array of pressure-sensor cells. Additionally, the methods, systems, and apparatuses include integrated circuitry communicatively coupled to the pressure-sensor arrangement that senses pressure changes exhibited by changes in capacitance or vibrational characteristics. | 12-11-2014 |