Abstract: A system and method for controlling the delivery of ultrasound energy to a subject is provided. In particular, such a system and method are capable of safely disrupting the blood-brain barrier. Ultrasound energy is delivered to produce cavitation of an ultrasound contrast agent at a selected pressure value. An acoustic signal is acquired following cavitation, from which a signal spectrum is produced. The signal spectrum is analyzed for the presence of harmonics, such as subharmonics or ultraharmonics. When subharmonics or ultraharmonics are present, the pressure value is decreased for subsequent sonications. If a previous sonication resulted in no subharmonics or ultraharmonics being generated, then the pressure value may be increased. In this manner, the blood-brain barrier can be advantageously disrupted while mitigating potentially injurious effects of the sonication.

Abstract: A system and method is provided for generating ultrasound at the tip of an intravascular catheter. This may be used for the treatment of vascular occlusions, including chronic total occlusions (CTOs) and thrombotic occlusions (e.g., deep vein thrombosis, stroke, myocardial infarction). For instance, the systems and methods may be used to induce cavitation to enhance the enzymatic degradation of a vascular occlusion. In some configurations, the approach employs a hollow cylindrical transducer, electrically stimulated in the radial direction at a frequency corresponding to the length mode excitation, thereby projecting ultrasound forwards past the catheter tip. This design overcomes electrical impedance issues for the generation of low frequencies with a smaller diameter transducer capable of negotiating a coronary artery. The hole within the transducer may accommodate a guidewire to facilitate its placement adjacent to the proximal portion of the occlusion.

Abstract: The present disclosure provides for an imaging probe with a rotatable core which allows for rotating imaging assembly that is larger in diameter than the lumen in which the rotatable core resides, as well as methods to construct said probes. The imaging probes are generally elongate flexible imaging catheters for use in cardiovascular procedures. The ability to have a smaller lumen to hold the rotatable core simplifies the inclusion of other functional components to the catheter and may improve the quality of the images produced.

Abstract: Ultrasound devices and systems are disclosed in which cooling of an active acoustic element of an ultrasound transducer is achieved via an electrically conductive member that extends beyond a proximal side of the active acoustic element to contact a heat exchanger. The electrically conductive member delivers electrical driving signals to the active acoustic element while conducting heat to the heat exchanger. A region of the proximal surface of the active acoustic element that is free from contact with the electrically conductive member may also absent from contact with a liquid or a solid, thereby facilitating reflection of ultrasound energy. The heat exchanger may include an electrically insulating fluid that contacts the electrically conductive member to remove the heat conducted through the electrically conductive member. The active acoustic element may be a multilayer lateral mode element, and the electrically conductive member may form an electrode of the lateral mode element.

Abstract: Intravascular imaging catheters are provided that include a distal sheath portion having a lumen that is configured to optionally receive a guidewire or an imaging assembly. The distal sheath portion may be configured to have dimensions such that when a guidewire is inserted through the lumen and extends through a distal exit port, the distal sheath portion may be employed as a microcatheter. External tissue may be imaged at a location at or near the distal end of the catheter, enabling, for example, the controlled imaging of a total occlusion, and the positioning of the distal end (and guidewire) within a true lumen associated with a total occlusion. A structural stop may be provided at or near the distal end of the distal sheath portion to prohibit extension of the imaging assembly out of the distal exit port, while permitting the extension of the guidewire through the distal exit port.

Abstract: Disclosed herein is an instrument that enables the in situ formation of architected planar biomaterials and tissues by translating a printer head along a deposition surface such as a patient having burn injuries. In handheld embodiments of the instrument, cell-laden biopolymer solutions are perfused through a moving microfabricated printer head and deposited onto a stationary planar surface or a wound. The printer head may be translated via a drive mechanism. A soft deformable roller mitigates further damage to the injured area of skin as it rolls over it and a gimbal mechanism to which the printer head is attached is in contact with the injured tissue but is configured so that the printer head while in contact with tissue, does not exert undue pressure on the would area.

Abstract: Systems and methods are disclosed that facilitate the reduction of both radio frequency (RF) noise and photoacoustic artefacts in differential photoacoustic radar imaging through a multi-step electrical and optical domain calibration method. An example two-step calibration method involves reducing RF image noise via an initial calibration step that involves the control of the relative amplitudes and phases of electrical driving modulation waveforms, while a second calibration step involves the differential suppression of photoacoustic artefact signals via tuning, in the optical domain, of the relative intensity the optical beams that are delivered to the sample. Another example embodiment involves the use of the standard deviation of the unwrapped phase that is obtained, after performing frequency-domain cross-correlation and an inverse transform to the time domain, to improve the amplitude signal that is employed to generate a differential photoacoustic radar image.

Abstract: An apparatus for slicing a cartilage sample includes a rear cartilage support cup, a cartilage clamp, a front cartilage support, a cartilage receiving region, and a cartilage cutting element. The cartilage clamp has first and second clamp members spaced apart from and aligned in a clamping direction transverse to a longitudinal axis. The cartilage receiving region is bounded by the first and second clamp members, the front cartilage support, and the rear cartilage support cup. The cartilage cutting element is spaced rearwardly from the front cartilage support by a cartilage slice thickness, the cartilage cutting element being movable across the cartilage receiving region in a cutting direction transverse to the longitudinal axis.

Abstract: Systems and methods are provided for performing transcranial diagnostic procedures using a transcranial ultrasound transducer array. The array elements are positioned and oriented such that far field regions respectively associated therewith spatially overlap within the brain of a patient. The array elements may be oriented approximately normal to the skull, permitting efficient coupling of ultrasound energy into the brain. The array elements are controlled to generate ultrasound pulses, where the timing of the pulses is controlled, based on registration between the array elements and volumetric image data, such that ultrasound energy is focused at a target within spatially overlapping far fields of the array elements. The transcranial ultrasound transducer array elements may be positioned and oriented relative to the skull such that their respective ultrasound beams are focused within the skull and diverging with the brain.

Abstract: Systems, methods and devices are provided for performing diagnostic or therapeutic transcranial procedures using a patient-specific transcranial headset. The patient-specific headset may include a patient-specific frame that is fabricated, according to volumetric image data, to conform to an anatomical curvature of a portion of a patient's head. The patient-specific frame is configured to support a plurality of transducers in pre-selected positions and orientations, which may be spatially registered to the volumetric image data. This spatial registration may be employed to control at least a portion of the transducers to focus energy at a pre-selected tissue region.

Abstract: Systems and methods are provided for the denoising of images in the presence of broadband noise based on the detection and/or estimation of in-band noise. According to various example embodiments, an estimate of broadband noise that lies within the imaging band is made by detecting or characterizing the out-of-band noise that lies outside of the imaging band. This estimated in-band noise may be employed for denoise the detected imaging waveform. According to other example embodiments, a reference receive circuit that is sensitive to noise within the imaging band, but is isolated from the imaging energy, may be employed to detect and/or characterize the noise within the imaging band. The estimated reference noise may be employed to denoise the detected in-band imaging waveform.

Abstract: An ultrasound phased array transducer is disclosed that achieves suppression of grating lobes through the incorporation of a coupling layer, where the coupling layer is positioned adjacent to the phased array transducer such that an ultrasound beam propagates through the coupling layer prior to encountering a propagation medium. The phased-array elements may be provided such that one or both of the array pitch and a lateral extent of each ultrasound transducer element is larger than half of the ultrasound wavelength in the propagation medium. Grating lobes within the coupling layer and the propagation medium may be reduced or suppressed by selecting a coupling material having a speed of sound that exceeds that of the propagation medium. The coupling layer may have a thickness sufficient for the generation of a wavefront, and the coupling layer may be formed from a viscous or viscoelastic material.

Abstract: In at least some examples, a method of treating an eye, includes (i) imaging a patient's vitreous using a probe, (ii) defining a window on a desired region of the vitreous, (iii) administering ultrasonic energy treatment to the desired region within the window, (iv) continually monitoring the treatment via the probe, (v) adjusting a characteristic of the ultrasonic energy treatment based on the monitoring, (vi) re-imaging the desired region of the vitreous after the treatment is administered, and (vii) evaluating or observing the desired region to determine whether a target percentage of a vitreous opacity has been resolved.

Abstract: Described here are systems and methods for positioning a surgical implant, such as a glenoid component, or other medical device intra-operatively. In general, the systems and methods described in the present disclosure implement a computer vision system, which may be a structured light computer vision system, together with a suitable optical tracker as an accurate intra-operative tool for predicting post-operative implant position in surgical procedures.

Abstract: A dual frequency transducer array includes one or more low frequency transducer arrays and a high frequency transducer array. Unfocused ultrasound such as plane waves are transmitted by the one or more low frequency transducer arrays in a number of different directions into an imaging region of the high frequency transducer array. High frequency echo signals produced by excited contrast agent in the imaging region are received by the high frequency transducer array to produce a contrast agent image. In another embodiment, the high frequency transducer produces unfocused ultrasound to excite the contrast agent in the imaging region and the low frequency transducer(s) receives low frequency echo signals from the excited contrast agent. A tissue image is created from echo signals received by the high or low frequency transducer. Echo data from the tissue image and the contrast agent image are combined to produce a combined tissue/contrast agent image.

Abstract: An interventional therapy system may include at least one catheter configured for insertion within an object of interest (OOI); and at least one controller which configured to: obtain a reference image dataset including a plurality of image slices which form a three-dimensional image of the OOI; define restricted areas (RAs) within the reference image dataset; determine location constraints for the at least one catheter in accordance with at least one of planned catheter intersection points, a peripheral boundary of the OOI and the RAs defined in the reference dataset; determine at least one of a position and an orientation of the distal end of the at least one catheter; and/or determine a planned trajectory for the at least one catheter in accordance with the determined at least one position and orientation for the at least one catheter and the location constraints.

Abstract: Systems and methods are provided for the denoising of images in the presence of broadband noise based on the detection and/or estimation of in-band noise. According to various example embodiments, an estimate of broadband noise that lies within the imaging band is made by detecting or characterizing the out-of-band noise that lies outside of the imaging band. This estimated in-band noise may be employed for denoise the detected imaging waveform. According to other example embodiments, a reference receive circuit that is sensitive to noise within the imaging band, but is isolated from the imaging energy, may be employed to detect and/or characterize the noise within the imaging band. The estimated reference noise may be employed to denoise the detected in-band imaging waveform.

Abstract: Systems and methods for using quantitative ultrasound (“QUS”) techniques to generate imaging biomarkers that can be used to assess a prediction of tumor response to different chemotherapy treatment regimens are provided. For instance, the imaging biomarkers can be used to subtype tumors that have resistance to certain chemotherapy regimens prior to drug exposure. These imaging biomarkers can therefore be useful for predicting tumor response and for assessing the prognostic value of particular treatment regimens.

Abstract: The present application is in the field of imaging reagents. In particular, the present application relates to labelled fluorocarbon imaging reagents, the preparation of the reagents, and their uses for imaging such as PET scanning.

Abstract: A system and method for efficiently transmitting and receiving focused ultrasound through a medium, such as bone, is provided. The focal region of the focused ultrasound is iteratively updated to provide an improved focus through the medium. This method may be carried out using a transducer assembly that includes two or more transmit arrays each operating at a different frequency. An initial focus is set and updated by delivering focused ultrasound with a lower frequency transmit array. The phase corrections determined in the first iteration are applied to subsequently higher frequency transmit arrays and received signals, and the process repeated until a desired focus or image resolution is achieved.