Kenergy, Inc.

Other

Stephen Denker

Cherik T Bulkes

Arthur Julius Beutler

Cherik Bulkes

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.

MRI compatible implanted lead-electrode interface

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.

Signal sensing in an implanted apparatus with an internal reference

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.

MRI compatible electrical lead for an implanted electronic medical device

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.

MRI compatible implanted electronic medical device

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.

MRI compatible implanted electronic medical device with power and data communication capability

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. The lead may further comprise a conducting layer formed by coating a material consisting of medium conducting particles in physical contact with each other and a mechanically flexible, biocompatible layer forming an external layer of lead and in contact with body tissue or body fluids.

MRI compatible implanted electronic medical lead

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.

Composite waveform based method and apparatus for animal tissue stimulation

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.

Radio frequency antenna for a wireless intravascular medical device

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.

Class-E radio frequency amplifier for use with an implantable medical device

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.

A medical device adapted for implantation into a patient receives electrical power from an extracorporeal power supply. The medical device has a first receiver for a first wireless signal, a power circuit that extracts energy from the first wireless signal to power the medical device, and a feedback signal generator that transmits a second wireless signal indicating a magnitude of energy extracted from the first wireless signal. The extracorporeal power supply includes a source of electrical power and a power transmitter that emits the first wireless signal. A second receiver enables the extracorporeal power supply to receive the second wireless signal. A feedback controller manipulates the first wireless signal in response to the second wireless signal to ensure that sufficient electrical energy is provided to the medical device without wasting electrical power from the source.

Extracorporeal power supply with a wireless feedback system for an implanted medical device

A medical device, such as a cardiac pacing device for an animal, includes an intravascular antenna that has a first coil for engaging a wall of a first blood vessel to receive a radio frequency signal. The first coil includes a first winding wound helically in a rotational direction along a longitudinal axis from a first end of the coil to a second end. A second winding that is connected to the a first winding at the second end, is wound helically in the same rotational direction along the longitudinal axis from the second end to the first end. An electronic circuit is implanted in the animal and is connected to the antenna to receive an electrical signal therefrom.

Wireless intravascular medical device with a double helical antenna assembly

A Class-E power amplifier includes a choke and a switch connected in series between a source of a supply voltage and circuit ground and connected to an inductively coupled coil. 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. A feedback signal, indicating an intensity if the signal at the amplifier output node is used to vary the input signal to the Class-E power amplifier and thereby control operation of the switch.

Class-E radio frequency power amplifier with feedback control

An radio frequency antenna assembly is provided for a medical device such as one capable of being implanted into a patient. The antenna assembly includes a plurality of antennas, each oriented to receive a radio frequency signal propagating along a different axis. This facilitates reception of the radio frequency signal regardless of the orientation of its propagation axis to the medical device. In other cases, the radio frequency signal has a plurality of components, each propagating along a different axis, and each antenna of the assembly receives a different one of those components. The individual electrical signals produced in each antenna are additively combined into a single signal having greater strength than each of the individual electrical signals.

Implantable medical apparatus having an omnidirectional antenna for receiving radio frequency signals

An abnormally rapid ventricular cardiac rate that results from atrial fibrillation can be reduced by stimulating a vagal nerve of the heart. An apparatus for such stimulation includes a power transmitter that emits a radio frequency signal. A stimulator, implanted in a blood vessel adjacent the vagal nerve, has a pair of electrodes and an electrical circuit thereon. The electrical circuit receives the radio frequency signal and derives an electrical voltage from the energy of that signal. The electrical voltage is applied in the form of pulses to the pair of electrodes, thereby stimulating the vagal nerve. The pattern of that stimulating pulses can be varied in response to characteristics of the atrial fibrillation or the ventricular contractions.

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Mequon, WI, United States of America

Stephen Denker