Abstract: An ultrasound probe 20 includes a transducer 32 capable of pivotal and rotational motion where the pivotal motion is through the plane of rotation. The transducer 32 is also capable of revolving around an axis of revolution 132 so that the transducer 32 can move relative to three axes. The probe 20 is designed such that the transducer 32 can be mounted at the tip of said probe 20 and allow for the above freedom of motion.

Abstract: A biopsy attachment 90 for a ultrasound probe 10 includes a frame 92 and a device 100, 102 for mounting the frame 92 to the probe 10 in order to align the frame 92 relative to the probe 10. The biopsy 90 attachment further includes a biopsy needle guide 106 and a device 94, 96 for pivotally moving the biopsy needle guide from an undeployed position, adjacent to an ultrasound transparent window 24, to a deployed position which is above and spaced from the ultrasound transparent window 24, in order to guide a biopsy needle 132 to the desired biopsy location.

Abstract: An automated magnetic field shimming process for magnetic resonance spectroscopic imaging (MRSI) uses doubly phase encoded NMR spin echo responses in conjunction with multiple fourier transformation to derive a spectroscopic plot for each voxel in a three-dimensional array of voxels in an image volume (including portions of a living subject) which is to be subsequently subjected to MRSI using NMR FID or spin echo responses. The thus derived hydrogen peak frequency is taken as a measurement of existing static magnetic field intensity within that voxel and adjusted shim coil currents are calculated so as to reduce or minimize nonuniformity of the static magnetic field. A nonexistent pseudo shim coil having an assumed uniform shim contribution may enhance the resulting field homogeneity. The auto shimming procedure may be applied iteratively as required to achieve the predetermined degree of field uniformity.

Abstract: A mobile X-ray machine utilizes batteries to provide electrical power to produce high-voltage necessary to generate X-rays during a X-ray exposure. A battery charger circuit is used to supplement the battery during the X-ray exposure and charges the batteries during non-exposure periods. By using batteries to power the X-ray generating device, the X-ray machine is capable of being operated from 110 volt AC power sources permitting the machine to be mobile due to its ability of being operated from ordinary house current.

Abstract: A dynamic calibration and self-check circuit for a mobile X-ray machine. A high voltage regulator circuit provides dynamic regulation of peak anode voltage and a tube current regulator circuit provides dynamic regulation of the X-ray filament current which controls the X-ray tube current. In the regulation of the anode voltage, a voltage sensor provides continuous feedback of the actual anode voltage of the tube to the regulation circuit. A processor selects a predetermined value for the pulse width duration of the high voltage regulator. When an exposure cycle commences, the preselective value is compared with the actual sensed value in an error amplifier. The error amplifier generates an error signal which varies the pulse width of the drive signal to control the peak high voltage to the anode. In the control of the tube current, a sensor which measures the actual tube current is compared with a predetermined value selected by the processor in a second error amplifier.

Abstract: A positioning device for a surface coil used in NMR scanning is described. A non-metallic container allows a MRI surface oil to reside therein. An elongated rod extending through an opening on a side of the container is attached to the coil. A clear cover is placed over the container which is then placed under the patient. As the NMR scanning is performed for medical diagnosis, the coil is adjusted to the desired position by movement of the rod.

Abstract: A surgical instrument guide for use in conjunction with an ultrasound probe and the method of use is described. The guide comprises an ultrasound probe socket disposed in a housing so that it can pivot or be locked in place with respect to the housing. An instrument holder adapted to fit in the probe socket and hold a surgical instrument along its longitudinal axis is also provided. The housing has external threads on the bottom thereof to enable the device to be screwed into the skull.

Abstract: A transducer drive assembly is disclosed having particular application for use in medical diagnostic imaging systems. The drive assembly includes a rotor coupled to drive means for rotation about its longitudinal axis. The rotor is formed such that it includes an integrally formed contact plate which extends upwardly from a generally flat rotor face at a given angle. A transducer is carried in a cradle which is mounted for pivotal movement, and includes a lower base portion having a generally cylindrical cross section. The lower base portion of the cradle is disposed such that it is maintained in physical contact with the rotor contact plate at all times. The rotation of the rotor applies force to the lower base of the cradle resulting in the oscillation of the cradle about the pivot points. The transducer is thereby oscillated back and forth about the pivot points in a uniform and continuous movement so long as the rotor continues to rotate.

Abstract: An ultrasonic scanner for medical diagnostics is disclosed. The scanner includes an upper head assembly and a lower drive assembly. The upper head assembly includes a fluid chamber filled with a liquid acoustic couplant. An oscillating transducer is driven in an asymmetric motion by a linkage coupled off-center to a flywheel within the fluid chamber. An inflatable bladder is provided in the upper assembly which is in fluid communication with the fluid chamber. The application of force to the membrane boot of the scanner forces fluid into the bladder. Once the external pressure is removed, the bladder is biased such that it is compressed, thereby forcing fluid to return to the fluid chamber and maintaining a generally constant pressure within the chamber. Supporting electronics are provided including means for compensating for the asymmetric motion of the transducer.

Abstract: A multi-mode scanner head employing split (semicircular transducers) is described. In some modes such as simultaneous B-scan and M-scan each transducer moves independent of the other. For continuous Doppler mode the transducers move together. The relatively small, hand-held scanner head is particularly useful for cardiac examinations.

Abstract: A data acquisition head for an ultrasonic imaging system which employs a plurality of transducers is disclosed. The transducers are rotated in a liquid filled chamber at a constant rate, each about an axis perpendicular to its transmission axis. The transducers are sequentially activated as their transmission axes cross a semi-rigid membrane which is in contact with the body. The acoustic impedance of the liquid and membrane, and the thickness of the membrane, are matched to enhance transmission. In one embodiment, the membrane is one-half or a full wavelength thick and comprises a low density polyethylene and the liquid has an acoustic impedance approximately equal to that of the polyethylene.

Abstract: An ultrasound imaging apparatus is described. The hand-held device includes a first oscillating transducer for providing a B-scan display and an offset second transducer which is manually positioned for providing Doppler data. The transducer pulses are interlaced and Doppler transmissions are inhibited to permit B-scan transmissions. However, circuits provide a continuous signal representing a Doppler signal when the Doppler transmissions are inhibited.

Abstract: An apparatus and method for mapping data associated with spacial polar angles into a Cartesian coordinate system is disclosed. In the described application, ultrasound returns from a rotating transducer are mapped into a memory to permit presentation on a raster scanned display. A tangent function is used to compute X and Y locations in a digital differential analyzer. The selection of data for these locations is controlled with a secant function by a second digital differential analyzer to minimize quantizing errors.