Abstract: When transesophageal echocardiography is used to obtain a transgastric short axis view of the left ventricle of the heart, the best place to position the transducer is in the fundus of the stomach, aimed up through the left ventricle. The probes disclosed herein facilitate placement of the transducer in the optimum position within the fundus, despite wide variations in the distance between the lower esophageal sphincter and the fundus among different subjects. In one preferred embodiment, the ultrasound probe uses a bending section with a series of vertebrae and stiffening that is more flexible proximally and less flexible distally, which causes the probe to bend relatively sharply at the point where the probe exits the lower esophageal sphincter.

Abstract: Disclosed are computer-implemented methods, systems, and computer program products for displaying superimposed image contours. A first centroid or center-of-mass of a contour extracted from a first image that depicts a moving object as the object appeared at a first time is calculated. A second centroid or center-of-mass of a second contour extracted from a second image that depicts the object as the object appeared at a second time is also calculated. The second image depicts the object in substantially the same plane as the first image. The first and second contours are displayed with the respective first and second centroids or centers-of-mass positioned at a common location. In some implementations, the images are ultrasound images depicting, for example, a human heart. The images can be transgastric short axis views of the human heart.

Abstract: Transesophageal echocardiography is implemented using a miniature transversely oriented transducer that is preferably small enough to fit in a 7.5 mm diameter probe, and most preferably small enough to fit in a 5 mm diameter probe. Signal processing techniques improve the depth of penetration to the point where the complete trans-gastric short axis view of the left ventricle can be obtained, despite the fact that the transducer is so small. The reduced diameter of the probe (as compared to prior art probes) reduces risks to patients, reduces or eliminates the need for anesthesia, and permits long term direct-visualization monitoring of patients' cardiac function.

Abstract: Methods and apparatuses are disclosed for positioning a valve or other device in a patient's body (e.g., in the patient's heart) using an ultrasound system in combination with position sensors. One position sensor is mounted in the ultrasound probe so that a geometric relationship between the position sensor and the ultrasound transducer is known, and another position sensor is mounted in the device installation apparatus so that a geometric relationship between the position sensor and the device is known. The device's position with respect to the imaging plane is determined based on the detected positions of the position sensors and the known geometric relationships. Images of the imaging plane are displayed, and an indication of the device's position with respect to the imaging plane is outputted.

Abstract: Transesophageal echocardiography is implemented using a miniature transversely oriented transducer that is preferably small enough to fit in a 7.5 mm diameter probe, and most preferably small enough to fit in a 5 mm diameter probe. Signal processing techniques improve the depth of penetration to the point where the complete trans-gastric short axis view of the left ventricle can be obtained, despite the fact that the transducer is so small. The reduced diameter of the probe (as compared to prior art probes) reduces risks to patients, reduces or eliminates the need for anesthesia, and permits long term direct-visualization monitoring of patients' cardiac function.

Abstract: A device (e.g., a valve) can be visualized in a patient's body (e.g., in the patient's heart) using an ultrasound system with added position sensors. One position sensor is mounted in the ultrasound probe, and another position sensor is mounted in the device installation apparatus. The device's position with respect to the imaging plane is determined based on the detected positions of the position sensors and known geometric relationships. A representation of the device and the imaging plane, as viewed from a first perspective, is displayed. The perspective is varied to a second perspective, and a representation of the device and the imaging plane, as viewed from the second perspective, is displayed. Displaying the device and the imaging plane from different perspectives helps the user visualize where the device is with respect to the relevant anatomy.

Abstract: When transesophageal echocardiography is used to obtain a transgastric short axis view of the left ventricle of the heart, the best place to position the transducer is in the fundus of the stomach, aimed up through the left ventricle. The probes disclosed herein facilitate placement of the transducer in the optimum position within the fundus, despite wide variations in the distance between the lower esophageal sphincter and the fundus among different subjects. In one preferred embodiment, the ultrasound probe uses a bending section with a series of vertebrae and stiffening that is more flexible proximally and less flexible distally, which causes the probe to bend relatively sharply at the point where the probe exits the lower esophageal sphincter.

Abstract: Ultrasound transducers can be fabricated by bonding a block of piezoelectric material having a conductive coating to a flex circuit that has a conductive region and at least 20 conductive traces disposed on an insulating substrate. The block of piezoelectric material is then diced so as to cut all the way through the block of piezoelectric material and all the way through the conductive region, and part way through, but not completely through, the insulating substrate. The dicing is performed so that the first conductive region is divided into at least 20 regions that are electrically isolated from each other, and each of the at least 20 regions is in electrical contact with a respective one of the at least 20 conductive traces.

Abstract: An ultrasound transducer that includes a backing layer, an insulating layer disposed on top of the backing layer, and a plurality of conductive traces disposed on top of the insulating layer are disclosed. Each of the conductive traces has an upper face. A plurality of transducer elements, each having (a) a core of piezoelectric material and (b) a conductive coating disposed beneath the core, are bonded directly to the upper face of a respective one of the plurality of conductive traces. Methods for fabricating ultrasound transducers are also disclosed.

Abstract: An ultrasound transducer that includes a backing layer, an insulating layer disposed on top of the backing layer, and a plurality of conductive traces disposed on top of the insulating layer are disclosed. Each of the conductive traces has an upper face. A plurality of transducer elements, each having (a) a core of piezoelectric material and (b) a conductive coating disposed beneath the core, are bonded directly to the upper face of a respective one of the plurality of conductive traces. Methods for fabricating ultrasound transducers are also disclosed.

Abstract: A phased array ultrasound transducer is made from a plurality of independently excitable elements that are arranged in a row in the azimuthal direction, configured so that azimuthal aiming of an outgoing ultrasound beam is controlled by timing the excitation of the elements. The geometry of the elements is configured to focus the outgoing beam in the elevation direction so as to improve the images of target regions located at or about a particular radial distance. In some embodiments, this is accomplished by forming each element from a plurality of subelements that are stacked in the elevation direction, with the subelements of any given element all (a) wired together and (b) positioned at about the same distance from a substantially rod-shaped focal region.

Abstract: When transesophageal echocardiography is used to obtain a transgastric short axis view of the left ventricle of the heart, the best place to position the transducer is in the fundus of the stomach, aimed up through the left ventricle. The probes disclosed herein facilitate placement of the transducer in the optimum position within the fundus, despite wide variations in the distance between the lower esophageal sphincter and the fundus among different subjects. In one preferred embodiment, the ultrasound probe uses a bending section with a series of vertebrae and stiffening that is more flexible proximally and less flexible distally, which causes the probe to bend relatively sharply at the point where the probe exits the lower esophageal sphincter. The flexibility of the proximal-most portion of the bending section is preferably greater than or equal to the flexibility of the interface between the bending section and the shaft.

Abstract: To keep the temperature of an ultrasound probe down, the probe is operated at a low frame rate (with correspondingly low heat generation) for the vast majority of time. Probe operation is only switched to the high frame rate temporarily at times when high temporal resolution is needed, preferably under operator control. The probe is only operated at the high frame rate for a short period of time, during which a burst of images with high temporal resolution is obtained. After capturing the short burst of images, the frame rate is cut back, which reduces the generation of heat.

Abstract: A connectorized ultrasound probe includes a distal section that is configured for insertion into a patient's body and a proximal section configured to interface the distal section with an ultrasound system. The distal section is easily attachable and detachable from the proximal section using at least one set of connectors. When connected, a user-operated actuator located on the proximal section controls the bending of the distal section, and the ultrasound system sends driving signals to and receives return signals from the ultrasound transducer via the proximal section. This arrangement is particularly advantageous for long term monitoring, because the disconnectability of the proximal section makes it possible to leave the distal section in place in the patient for longer periods of time without undue discomfort.

Abstract: A connectorized ultrasound probe includes a distal section that is configured for insertion into a patient's body and a proximal section configured to interface the distal section with an ultrasound system. The distal section is easily attachable and detachable from the proximal section using at least one set of connectors. When connected, a user-operated actuator located on the proximal section controls the bending of the distal section, and the ultrasound system sends driving signals to and receives return signals from the ultrasound transducer via the proximal section. This arrangement is particularly advantageous for long term monitoring, because the disconnectability of the proximal section makes it possible to leave the distal section in place in the patient for longer periods of time without undue discomfort. In some preferred embodiments, the mechanical interface is made before the electrical interface when the distal section is connected to the proximal section.

Abstract: Signal processing techniques reduce the impact of noise (including speckle noise and shot noise) on ultrasound images by reducing the intensity of pixels that are probably noise and increasing the intensity of pixels that are probably signal. The decision of whether a given pixel is probably noise or probably signal is made based on spectral characteristics of the samples in and around the given pixel, based on knowledge of the expected spectral characteristics of the signal and the expected spectral characteristics of the noise.

Abstract: The visibility of features in ultrasound images that include at least two types of tissue can be improved by processing the images using a variety of algorithms. In one such algorithm, the ratio of power in a first spatial frequency band to power in a second spatial frequency band is computed for a plurality of samples of a received ultrasound return signal that are associated with a given pixel. In another such algorithm, the ratio of power in a first spatial frequency band to total power is computed. With both algorithms, the computed ratio is then mapped to a gain for the given pixel, the raw intensity of the given pixel is modified in accordance with the gain, and the pixel is displayed with the modified intensity.