Abstract: A spiral catheter apparatus and method of use for access to, and laser or other treatment within, cavities and organs in the human body, the apparatus having a spiral member with a selected curvilinear shape, but flexible enough to assume a temporarily elongated shape such that the spiral member can be extended through the vasculature in the temporarily elongated shape and will assume the selected curvilinear shape when extended into a body cavity or organ, the spiral member formed of a superelastic or other material, the selected curvilinear shape serving to securely position the spiral member adjacent a selected surface within the body cavity or organ for laser or other treatment with a laser delivery device or other functional device on a selected surface, the apparatus further having a main catheter shaft with at least two hollow lumens extending therethrough, the first lumen for slidably guiding the main catheter shaft over the spiral member into a first position adjacent the selected surface, and the se

Abstract: A dual purpose biomedical device has a solid flexible ultrasonic couplant sheet or pad formed from an electrically conductive hydrogel. The hydrogel sheet has an upper surface that is exposed during use for allowing direct contact between an ultrasonic generator and the hydrogel sheet and a lower surface that is placed during use against the skin of a patient whereby the hydrogel sheet transmits ultrasonic waves to and from the body of the patient. An adhesive is operatively associated with the hydrogel sheet for adhering the sheet to the skin. A removable and replaceable electrically conductive flexible sheet is supported upon the upper surface of the hydrogel sheet for establishing electrical contact with the patient through the hydrogel sheet when lowered into contact with the hydrogel sheet. The conductive sheet is removable therefrom for allowing the ultrasonic generator to contact the hydrogel sheet.

Abstract: A camera generates digital image signals representing an image of one or more natural or artificial fiducials on a patient positioned on treatment or diagnosis equipment. A processor applies multiple levels of filtering at multiple levels of resolution to repetitively determine successive fiducial positions. A warning signal is generated if movement exceeds certain limits but is still acceptable for treatment. Unacceptable displacement results in termination of the treatment beam. Tracking templates can be generated interactively from a display of the digital image signals or through automatic selection of an image having the median correlation to an initial template. A gating signal synchronized to patient breathing can be extracted from the digital image signals for controlling the radiation beam generator.

Abstract: A method for imaging an organ or internal structure within a body to obtain three-dimensional reconstruction of the organ or internal structure. The method includes steps of providing an intraluminal ultrasound imaging system capable of obtaining echographic images of the surrounding of a catheter imaging tip located inside the body of a patient, and a catheter tracking system comprising at least one ultrasound transducer mounted adjacent the imaging tip of an intraluminal ultrasound catheter for insertion into a patient, a plurality of transducers located away from said intraluminal ultrasound catheter so as to form a reference frame, and circuitry for calculating positions of the plurality of frame transducers relative to each other and positions of said catheter tip transducers relative to said plurality of frame transducers.

Abstract: A method and apparatus for automated measuring of a diameter of a first region enclosed in a second region internal to a living organism, wherein the first and second regions consist of different cellular matter. One embodiment of the invention includes generating a plurality of trial diameters, wherein each trial diameter includes an inner and outer region and has a different length. An ultrasonic measurement is taken of the inner region and the outer region for each trial diameter. The difference is determined for the ultrasonic measurements corresponding to the inner and outer regions of each trial diameter. The trial diameter which most closely corresponds to the diameter of the first region is then selected, wherein the difference of the ultrasonic measurements corresponding to the inner and outer regions is greatest for the trial diameter which most closely corresponds to the diameter of the first region.

Abstract: Improved methods and apparatuses related to laser-assisted transmyocardial revascularization, and more particularly, to improved methods and apparatuses for precisely positioning a fiber-optic or other waveguide adjacent the area or areas to be lased, including at positions adjacent the posterior epicardial and endocardial surfaces of the heart and at trans-septal positions within the chambers of the heart, thereby making possible the creation of channels in myocardial tissue at precisely the positions in the heart where ischemia or infarction or other have rendered such treatment desirable or necessary. These methods and apparatuses can be adapted for use in surgical applications throughout the human body or in animals for transmitting laser energy precisely, at predetermined positions and to predetermined depths.

Abstract: Creatinine clearance is estimated in a patient by determining his or her body cell mass. In turn, the body cell mass of the patient is measured using bioimpedance analysis techniques. The determined value of body cell mass is normalized by the height.sup.2 of the patient. The body cell mass or its normalized value provides an indication of actual creatinine clearance in the subject through use of a predictive formula. From this prediction, accurate dosages of potentially nephrotoxic medications can be appropriately prescribed.

Abstract: A new design of therapeutic traction modality with closed loop traction force control based on EMG signals from selected muscle is developed for rehabilitation. This modality includes main traction controller, a high signal-to-noise ratio EMG scanning and processing units, A/D and D/A computer interface hardware, on-line self-adjusted traction force actuating unit, biofeedback control software, and audio/visual alarms. This new traction modality provide a breakthrough milestone for the open loop control architecture of conventional motorized traction machine. The kernel of this invented modality is to adaptively adjusting traction force based on real time detected EMG signals to ensure the safety, comfort, and effectiveness of traction therapy.

Abstract: A method and apparatus is provided for controlling rotation of an ultrasound transducer. In accordance with the method of the present invention, a user-operable actuator that is movable over a continuous range of positions and generates a first signal representing the position of the actuator is provided. The method includes the steps of transforming the first signal into a second signal representing a desired velocity. Preferably, the second signal is a nonlinear transform of the first signal. The method further provides for rotating the ultrasound transducer in accordance with the second signal. In accordance with the apparatus of the present invention, a probe having a control housing, an actuator that may be manually positioned within a range of positions, and a transducer housing coupled to the control housing, which transducer housing contains an ultrasound transducer that is rotatably mounted for scanning a plurality of planes in a body, is disclosed.

Abstract: An electrophysiological data collection system is described which includes a flash lamp for transmitting a stimulus to a subject, electrodes for deriving electrophysiologic data from the subject, an amplifier for processing the data, a contrast sensor for monitoring the flash lamp, an illumination sensor for measuring ambient light, and a connection box for controlling the amplifier according to the outputs of the contrast sensor and illumination sensor.

Abstract: An apparatus for analyzing body composition based on bioelectrical impedance analysis, and a method therefor are disclosed. The method for analyzing body composition includes the step of providing eight electrodes for being contacted to a right palm, a right thumb, a left palm, a left thumb, a right front sole, a right rear sole, a left front sole and a left rear sole. Then a switch is selected by a command of a micro-processor so as to form a current path. Then a current is made to flow through said selected electrodes and through a human body to an impedance measuring instrument. Then a switch is selected by a command of said micro-processor so as to form voltage electrodes. Then impedances for respective body portions are measured by means of the impedance measuring instrument. Then impedances of two body portions are decided based on the current and voltage of the impedance measuring instrument. Then the body composition is analyzed based on the measured impedance.

Abstract: An apparatus and method determine externally in a vertebrate subject an index of porosity and non-connectivity of a bone. A preferred embodiment has first and second transducers and a mounting arrangement for mounting the transducers in spaced relationship with respect to the bone. A signal generator,in communication with the first transducer, causes the first transducer to produce acoustic signals, having energy distributed over a frequency range, that are propagated into the subject and received by the second transducer along a path the includes the bone. Finally, the embodiment has a signal processor, in communication with the second transducer, for providing a measurement that is a function of at least one of spectral or temporal components of the sisal received by the second transducer. The transducers act like a point source and point receiver.

Abstract: A method and an apparatus are provided for storage and retrieval of measured aberration correction values used in adaptive focus ultrasound imaging. The aberration correction values, corresponding to an aberration region in an imaged subject, are measured at a transmit focal depth. The measured aberration correction values, typically delays, from a measurement depth are stored in a geometric aberration transform (GAT.TM.) table and transformed to aberration correction values at other focal depths for correcting the focus of both transmit and receive beamformers. The transformation is accomplished by using a geometric aberration transform (GAT.TM.) index table which retrieves one or more aberration correction values in the table for any desired depth.

Abstract: There is provided an ultrasonic diagnostic apparatus in which ultrasonic waves are transmitted into the subject to obtain received signals through receiving the ultrasonic waves reflected within the subject, thereby displaying an image based on the received signals. In the ultrasonic diagnostic apparatus, a contact or non-contact of the tip portion of the ultrasonic probe with the subject is detected. At the time point when the non-contact is detected, a display mode of a CRT display is changed from a dynamic image mode to a still image mode (a freeze mode), so that a desired image is displayed in the form of a still image.

Abstract: A transmitter directs a narrow RF ultrasonic beam through a body cavity to a receiver on the other side of the cavity. The beam is steered to be intercepted by audio signal sources in the body cavity, such as a fetal heart or multiple fetal hearts, which modulate the ultrasonic beam. The received parametric beam is demodulated and filtered to provide a relatively noise free audio reproduction of an audio signal source. In one embodiment, two transmitters are steered independently to direct respective beams to respective receivers to produce two signals and, thus, a binaural audio reproduction of an audio signal source. The audio reproduction is at a maximum when the two beams intersect at the audio signal source.

Abstract: Methods of and apparatus for preparing gas-filled liposomes are described. Gas-filled liposomes prepared by these methods are particularly useful, for example, in ultrasonic imaging applications and in therapeutic drug delivery systems.

Abstract: Acoustic imaging balloon catheters formed by a disposable liquid-confining sheath supporting a high fidelity, flexible drive shaft which carries on its end an ultrasound transducer and includes an inflatable dilatation balloon. The shaft and transducer rotate with sufficient speed and fidelity to produce real time images on a T.V. screen. In preferred embodiments, special features that contribute to the high fidelity of the drive shaft include the particular multi-filar construction of concentric, oppositely wound, interfering coils, a pre-loaded torque condition on the coils enhancing their interfering contact, and dynamic loading of the distal end of the probe, preferably with viscous drag. The coil rotating in the presence of liquid in the sheath is used to produce a desirable pressure in the region of the transducer.

Abstract: The catheter sensing and ablation arrangement allows location and cardiac abalation on a patient. The arrangement includes an electrically nonconductive catheter body, with a guide-wire lumen. The guidewire is electrically conductive, and, when the guidewire is assembled with the catheter, extends through the lumen, and is slideable therein. The guidewire has an enlarged distal end which, when retracted, blocks the guidewire lumen. The distal end of the catheter body has an exposed first electrode, which is connected to a terminal located near the proximal end. An action potential sensor is adapted for, in a sensing mode of operation, coupling to the proximal end of the guide wire and to the electrical terminal, for sensing action potentials appearing between the enlarged end of the guide wire and the first electrode, so the end of the guide wire may be moved to a cardiac location identifiable by the action potentials.

Abstract: Methods and apparatus for measuring and characterizing the localized electromagnetic wave absorption properties of biologic tissues in vivo, using incident electromagnetic waves to produce resultant acoustic waves. Multiple acoustic transducers are acoustically coupled to the surface of the tissue for measuring acoustic waves produced in the tissue when the tissue is exposed to a pulse of electromagnetic radiation. The multiple transducer signals are then combined to produce an image of the absorptivity of the tissue, which image may be used for medical diagnostic purposes. In specific embodiments, the transducers are moved to collect data from multiple locations, to facilitate imaging. Specific arrangements of transducers are illustrated. Also, specific mathematical reconstruction procedures are described for producing images from transducer signals.

Abstract: A catheter apparatus for monitoring cardiovascular function is provided. The catheter apparatus contains an elongated body having proximal and distal ends; a phased-array ultrasonic transducer; and an electrical conductor. The phased-array ultrasonic transducer is mounted proximate the distal end of the catheter body to transmit ultrasound and receive resultant echoes so as to provide a field of view within which flow rates can be measured and features imaged. The electrical conductor is disposed in the catheter body for electrically connecting the transducer to control circuitry external of the catheter.