Abstract:
Laparoscopic ultrasound has seen increased use as a surgical aide in general, gynecological, and urological procedures. The application of real-time three-dimensional (RT3D) ultrasound to these laparoscopic procedures may increase information available to the surgeon and serve as an additional intraoperative guidance tool. The integration of RT3D with recent advances in robotic surgery can also increase automation and ease of use. In one non- limiting exemplary implementation, a 1 cm diameter probe for RT3D has been used laparoscopically for in vivo imaging of a canine. The probe, which operates at 5 MHz, was used to image the spleen, liver, and gall bladder as well as to guide surgical instruments. Furthermore, the 3D measurement system of the volumetric scanner used with this probe was tested as a guidance mechanism for a robotic linear motion system in order to simulate the feasibility of RT3D/robotic surgery integration. Using images acquired with the 3D laparoscopic ultrasound device, coordinates were acquired by the scanner and used to direct a robotically controlled needle towards desired in vitro targets as well as targets in a post- mortem canine. The RMS error for these measurements was 1.34 mm using optical alignment and 0.76 mm using ultrasound alignment.
Abstract:
A method of generating an enhanced receive signal from a piezoelectric ultrasound transducer is described. The method comprises providing a piezoelectric ultrasound transducer comprising a piezoelectric element operable in flexural mode, receiving a acoustic signal by the piezoelectric element, applying a DC bias to the piezoelectric element prior to receiving the acoustic signal and/or concurrently with receiving the acoustic signal, and generating an enhanced receive signal from the piezoelectric element as a result of receiving the acoustic signal by the piezoelectric element. pMUT-based imaging probes using the above method are also described.
Abstract:
A hand-operated intracardiac echocardiography (ICE) catheter is described for flexed and rotational steering is described for improved catheter operation, control and less trauma on patients. The disclosed catheter assembly includes ultrasound transducers mounted upon a rotatable tip mounted on a distal end of a flexible elongate shaft. A set of steering lines are controlled by a steering actuator to articulate bidirectionally a distal segment of the catheter. Another steering actuator controls rotation of a torque member that, in turn is coupled to the rotatable tip. A user, through the steering actuators, affects repositioning the ultrasonic transducers by repositioning exposed control surfaces of the steering actuators lengthwise along the housing of the handle.
Abstract:
A dual-mode, capable of imaging and ablation, ultrasound array (110) integrated in a catheter is provided for minimally invasive treatment of arrhythmias. The catheter array is small enough for insertion through a peripheral vein and is longitudinally integrated with the catheter to have a side-view for tissue imaging and ablation. A high length/width array ratio creates a large aperture necessary for high power ablation densities. A catheter stabilization device (150) maintains a distance between the catheter array and the wall of a heart or vein. Visualization of anatomy and imaging of ablated tissue provides a guide for placing the lesion and assists in achieving a pattern of ablated tissue. The catheter is advanced to another area by catheter rotation and/or array steering or focusing. Gating the imaging and ablation processes to a heart cycle allows for accounting and compensation of heart motion and enables automation of an arrhythmia treatment.
Abstract:
A peritoneal ultrasound imager includes an elongated body less than about 20 inches in length that is adapted to be inserted through a cannula into or near the pericardium space, and an ultrasound transducer array at one end of the body that is suitable for ultrasound echocardiography. The cannula and ultrasound imager may be of a single piece construction. A method for imaging the heart includes introducing a cannula into the wall of a patient's chest, inserting the elongated body into the cannula, moving the inserted elongated body to a position near the heart, and imaging the heart with ultrasound echo.
Abstract:
A medical or surgical instrument (30), such as a catheter, micro-catheter, guide-wire, cannula, blade, and forceps, comprising one or more sensors (82) to allow measurement of parameters around or within the instrument, and methods for making and using the same, are disclosed. Also disclosed are methods and apparatuses for measuring fluid characteristics, such as blood characteristics, including, for example, velocity, flow direction, and pressure in a vascular system.
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 sensor (16) for an ultrasound imaging catheter (12) and methods of fabrication are provided. The sensor (16) may be based on a flex circuit (32) on which a block of piezoelectric sensor array transducer material is mounted. The flex circuit may include electrical conductors (34) that are electrically connected to electrodes on the piezoelectric blocks. A matching layer may be formed on the piezoelectric blocks between the blocks and the flex circuit substrate. Individual transducer array elements may be formed by dividing a piezoelectric block into a plurality of individual transducer elements after the matching layer has been formed. Cuts may be formed in the flex circuit substrate between adjacent transducer array elements to acoustically decouple adjacent elements. The flex circuit substrate and matching layers may have relatively high impedance to facilitate acoustic impedance matching between the sensor and the imaging environment.