Abstract: An implantable electrical lead that, upon implantation in an animal, is biocompatible and compatible with a magnetic resonance imaging scanner. The upon implantation in an animal has a body of dielectric material with a plurality of lumens and a plurality of insulated conductive helical coils embedded in one or more layers of dielectric material and placed within the plurality of lumens. Each helical coil is formed by one or more conductive wires having a predefined and controlled pitch and diameter. A layer of dielectric material separates the plurality of lumens, wherein the separation distance and properties of the dielectric material create a high impedance at the Larmor frequency of the magnetic resonance imaging scanner. A mechanically flexible, biocompatible layer forms an external layer of the electrical lead and is adapted to contact bodily tissue and bodily fluids of the animal.

Abstract: An electrical lead for implantation into an animal includes a cable to which a stimulation electrode is connected. The cable has a helical electrical conductor enclosed within an insulating sheath. The stimulation electrode has a tubular first contact band with a threaded lumen into which a portion of the helical electrical conductor is screwed. A second contact band has a threaded aperture and a helical electrode coil is screwed into both the threaded lumen and the threaded aperture. The two contact bands are separated so as to expose a portion of the electrode coil to enable electrical stimulation of tissue of the animal. Particular configurations of the helical electrode coil and the helical electrical conductor render the electrical lead compatible with MRI scanning.

Abstract: An implantable apparatus for sensing biological signals from an animal includes at least two electrodes disposed at locations to sense the biological signals. The electrode locations may be internal or external to the animal. Insulated conductors couple the electrodes via a passive network of filters to an instrumentation amplifier that has an internal voltage reference. Thus a sensed biological signal is filtered and amplified to provide an amplified differential signal. A signal analysis module processes amplified differential signal to determine at least one physiological parameter of the animal. The signal analysis module may include a first derivative zero detector for signal transition detection and feature detection and analysis. The apparatus may also comprise a signal presentation module to display amplified signals and physiological parameters associated with those signals.

Abstract: An electrical lead, for implantation in an animal, is compatible with an MRI scanner. The electrical lead has a first plurality of coiled insulated wires forming an outer layer of conductors that has a first inductance and a first capacitance, which act as a first parallel resonator tuned to a Larmor frequency of tissue in the animal. The lead may have a second plurality of coiled insulated wires forming an inner layer of conductors within the outer layer of conductors. The second plurality of coiled insulated wires has a second inductance and a second capacitance that act as a second parallel resonator tuned to the Larmor frequency. Those parallel resonators mitigate signals at the Larmor frequency from traveling along the respective coil. An electrically conductive layer extends around the inner and/or outer layer of conductors, and a layer of a biologically compatible material forms the electrical lead's exterior surface.

Abstract: One or more techniques are provided for determining the overall motion of an organ of interest relative to a viewer or imager. Motion data is acquired for the organ of interest and/or for one or more proximate organs using sensor-based and/or image data-based techniques. The sensor-based techniques may include electrical and non-electrical techniques. The image data-based techniques may include both pre-acquisition and acquisition image data. The motion data for the organ of interest and proximate organs may be used to determine one or more quiescent periods corresponding to intervals of minimal motion for the organ of interest and the proximate organs, which may be used to determine one or more gating points that may be used retrospectively, as well as one or more motion compensation factors that may be used to reduce motion-related artifacts during processing and reconstruction of the acquired image data.

Abstract: An implantable electronic medical device is compatible with a magnetic resonance imaging (MRI) scanner. The device has a housing with exterior walls, each formed by a dielectric substrate with electrically conductive layers on interior and exterior surfaces. A series of slots divide each layer into segments. Segmenting the layers provides high impedance to eddy currents produced by fields of the MRI scanner, while capacitive coupling of the segments provides radio frequency shielding for components inside the housing. Electrical leads extending from the housing have a pair of coaxially arranged conductors and traps that attenuate currents induced in the conductors by the fields of the MRI scanner.

Abstract: An antenna module, that is compatible with a magnetic resonance imaging scanner for the purpose of diagnostic quality imaging, is adapted to be implanted inside an animal. The antenna module comprises an electrically non-conducting, biocompatible, and electromagnetically transparent enclosure with inductive antenna wires looping around an inside surface. An electronic module is enclosed in an electromagnetic shield inside the enclosure to minimize the electromagnetic interference from the magnetic resonance imaging scanner.

Abstract: One or more techniques are provided for identifying a period of minimal motion for an organ of interest, such as the heart or lungs. Motion data is acquired for the organ of interest and for one or more proximate organs using sensor-based and/or image-based techniques. The sensor-based techniques may include electrical and non-electrical techniques. The image-based techniques may include both pre-acquisition and acquisition image data. The motion data for the organ of interest and proximate organs may be used to generate a set of multi-input motion data that may be processed to identify desired periods, such as periods of minimal motion, within the overall motion of the organ of interest.

Abstract: A technique for measuring and characterizing the motion of an internal organ is provided. The technique includes using two or more motion-sensitive sensors, disposed on a patient in a region of interest proximate to the internal organ, which acquire motion data along the surface of the patient. The motion data may then be processed and displayed to depict or characterize the mechanical motion undergone by the internal organ. The mechanical motion may be displayed as an image or video. In addition, the mechanical motion data may be combined with other measured data, such as electrical or acoustic data, or with images acquired by other imaging modalities to generate a composite image.

Abstract: One or more techniques are provided for determining the overall motion of an organ of interest relative to a viewer or imager. Motion data is acquired for the organ of interest and/or for one or more proximate organs using sensor-based and/or image data-based techniques. The sensor-based techniques may include electrical and non-electrical techniques. The image data-based techniques may include both pre-acquisition and acquisition image data. The motion data for the organ of interest and proximate organs may be used to determine one or more quiescent periods corresponding to intervals of minimal motion for the organ of interest and the proximate organs. The one or more quiescent periods may be used to determine one or more gating points that may be used prospectively, i.e., during image acquisition. In addition, the one or more quiescent periods may be used to determine one or more motion compensation factors that may be used during processing and reconstruction of the acquired image data.

Abstract: An implantable biocompatible lead that is also compatible with a magnetic resonance imaging scanner for the purpose of diagnostic quality imaging is described. The implantable electrical lead comprises a plurality of coiled insulated conducting wires wound in a first direction forming a first structure of an outer layer of conductors of a first total length with a first number of turns per unit length and a plurality of coiled insulated conducting wires wound in a second direction forming a second structure of an inner layer of conductors of a second total length with a second number of turns per unit length. The first and the second structures are separated by a distance with a layer of dielectric material. The distance and dielectric material are chosen based on the field strength of the MRI scanner.

Abstract: A medical apparatus, for artificially stimulating internal tissue of an animal, applies a composite voltage pulse to a pair of electrodes implanted in the animal. The composite voltage pulse is formed by a first segment and a second segment contiguous with the first segment, both of which have generally rectangular shapes. The amplitude of the first segment is significantly greater than, e.g. at least three times, the amplitude of the second segment. However, the second segment has a significantly longer duration than the first segment, e.g. at least three times longer. Preferably the integrals of the first and second segments are substantially equal.

Abstract: An apparatus includes a medical device for implantation in a blood vessel and a power supply adapted to be located outside the blood vessel. The extravascular power supply has a power transmitter that produces a radio frequency signal which is applied to an energy transmitting antenna. The energy transmitting antenna comprises first and second coils connected is series and wound around separate spaced apart, parallel axes axis wherein magnetic fields generated by each coil add together to produce a cumulative field. The receiving antenna, for positioning in a near field region of the cumulative field, has least one coil wound around a third axis that is aligned with the cumulative field.

Abstract: A radio frequency antenna is provided for use with a medical device for implantation into an animal. The antenna comprises a coil formed by a wire that includes a core formed of a shape-memory material with an electrically conductive first layer applied to an outer surface of the core. A second layer, of an electrically insulating and biologically compatible material, extends around the first layer. If necessary to reduce friction, a lubricant is placed between the first and second layers. If second layer is formed of a porous material or a non-biological compatible material, a biological compatible outer layer surrounds the second layer thereby providing a barrier that is impermeable to body fluids of the animal.

Abstract: An implantable apparatus for sensing biological signals from an animal includes at least two electrodes disposed at locations to sense the biological signals. The electrode locations may be internal or external to the animal. Insulated conductors couple the electrodes via a passive network of filters to an instrumentation amplifier that has an internal voltage reference. Thus a sensed biological signal is filtered and amplified to provide an amplified differential signal. A signal analysis module processes amplified differential signal to determine at least one physiological parameter of the animal. The signal analysis module may include a first derivative zero detector for signal transition detection and feature detection and analysis. The apparatus may also comprise a signal presentation module to display amplified signals and physiological parameters associated with those signals.

Abstract: An electrical lead for implantation into an animal includes a cable to which a stimulation electrode is connected. The cable has a helical electrical conductor enclosed within an insulating sheath. The stimulation electrode has a tubular first contact band with a threaded lumen into which a portion of the helical electrical conductor is screwed. A second contact band has a threaded aperture and a helical electrode coil is screwed into both the threaded lumen and the threaded aperture. The two contact bands are separated so as to expose a portion of the electrode coil to enable electrical stimulation of tissue of the animal. Particular configurations of the helical electrode coil and the helical electrical conductor render the electrical lead compatible with MRI scanning.

Abstract: A medical apparatus includes an extracorporeal power source that transmits electrical power via a radio frequency signal to a medical device implanted inside an animal. The extracorporeal power source has a Class-E amplifier with a choke and a semiconductor switch connected in series between a source of a supply voltage and circuit ground. An output node of the amplifier is formed between choke and the switch and connected to a transmitter antenna. A shunt capacitor couples the amplifier's output node to the circuit ground. Controlled operation of the switch produces bursts of the radio frequency signal that are pulse width modulated to control the amount of energy being sent to the implanted medical device.

Abstract: One or more techniques are provided for determining the overall motion of an organ of interest relative to a viewer or imager. Motion data is acquired for the organ of interest and/or for one or more proximate organs using sensor-based and/or image data-based techniques. The sensor-based techniques may include electrical and non-electrical techniques. The image data-based techniques may include both pre-acquisition and acquisition image data. The motion data for the organ of interest and proximate organs may be used to determine one or more quiescent periods corresponding to intervals of minimal motion for the organ of interest and the proximate organs. The one or more quiescent periods may be used to determine one or more gating points that may be used prospectively, i.e., during image acquisition, and retrospectively, i.e., after image acquisition.

Abstract: An electrical lead, for implantation in an animal, is compatible with an MRI scanner. The electrical lead has a first plurality of coiled insulated wires forming an outer layer of conductors that has a first inductance and a first capacitance, which act as a first parallel resonator tuned to a Larmor frequency of tissue in the animal. The lead may have a second plurality of coiled insulated wires forming an inner layer of conductors within the outer layer of conductors. The second plurality of coiled insulated wires has a second inductance and a second capacitance that act as a second parallel resonator tuned to the Larmor frequency. Those parallel resonators mitigate signals at the Larmor frequency from traveling along the respective coil. An electrically conductive layer extends around the inner and/or outer layer of conductors, and a layer of a biologically compatible material forms the electrical lead's exterior surface.

Abstract: A radio frequency antenna is provided for use with a medical device for implantation into an animal. The antenna comprises a coil formed by a wire that includes a core formed of a shape-memory material with an electrically conductive first layer applied to an outer surface of the core. A second layer, of an electrically insulating and biologically compatible material, extends around the first layer. If necessary to reduce friction a lubricant is place between the first and second layers. If second layer is formed of porous material or a non-biological compatible material, a biological compatible outer layer surrounds the second layer thereby providing a barrier that is impermeable to body fluids of the animal.