Abstract: Subdural arrays transmit electrocorticogram recordings wirelessly, across the patient's skull, allowing the craniotomy used for surgical placement of the arrays to be completely closed. In various embodiments, the arrays also respond to commands, applying signal patterns to the patient's brain for diagnostic and treatment purposes.

Abstract: Subdural arrays transmit electrocorticogram recordings wirelessly, across the patient's skull, allowing the craniotomy used for surgical placement of the arrays to be completely closed. In various embodiments, the arrays also respond to commands, applying signal patterns to the patient's brain for diagnostic and treatment purposes.

Abstract: Subdural arrays transmit electrocorticogram recordings wirelessly, across the patient's skull, allowing the craniotomy used for surgical placement of the arrays to be completely closed. In various embodiments, the arrays also respond to commands, applying signal patterns to the patient's brain for diagnostic and treatment purposes.

Abstract: A method for on-off modulation of a transmitter coil current of a high-Q resonant circuit transmitter comprising the steps of sensing a zero-crossing of the transmitter coil current and substantially instantaneously interrupting the transmitter coil current, and a high-Q resonant circuit transmitter for carrying out said method.

Abstract: A transponder system including a transponder and an interrogator having a transmission coil for producing a high-intensity electromagnetic field for inductively powering the transponder and two receiver coils for receiving a low-intensity electromagnetic field reradiated by the transponder. The transmission coil includes one or more conductive windings circumscribing a substantially polygonal volume of space. The receiver coils are diametrically disposed opposite one another within the volume space of the transmitter and are electrically connected to each other in a differential circuit relationship, the output of which is at a minimum when the two receiver coils receive approximately equal quantities of energy and is at a maximum when one of the receiver coils receives more electromagnetic energy from the transponder than the other receiver coil. The transponder uses a coil to derive both a power source and a clock pulse from the high-intensity field for powering and driving an identification circuit.

Abstract: A self-regulating Class E/resonant power converter includes a power switching device which is gated on at each transition between negative and positive half cycles of the load current by drive signals generated by a drive circuit, the rate at which the drive signals are generated being controlled by a zero crossing detector which monitors the load current and adjusts the frequency of the drive signals in correspondence with changes in the time between successive negative-to-positive zero crossings of the load current such that the power switching device continues to be switched on at substantially zero voltge, zero slope conditions to maintain the power converter operating at the optimal Class E frequency.

Abstract: This invention is directed to composite coating for maintaining low moisture levels at the surface of solid substrates. One embodiment of the invention comprises a coating having a desiccant layer between layers of the same or different elastomeric polymers. Another embodiment comprises a layer of elastomeric polymer covered with a layer of an elastomeric polymer/desiccant mixture. The composite coating may be applied to integrated circuits to prevent corrosion thereof.

Abstract: A transponder system including a transponder and an interrogator having a transmission coil for producing a high-intensity electromagnetic field for inductively powering the transponder and two receiver coils for receiving a low-intensity electromagnetic field reradiated by the transponder. The transmission coil includes one or more conductive windings circumscribing a substantially polygonal volume of space. The receiver coils are diametrically disposed opposite one another within the volume space of the transmitter and are electrically connected to each other in a differential circuit relationship, the output of which is at a minimum when the two receiver coils receive approximately equal quantities of energy and is at a maximum when one of the receiver coils receives more electromagnetic energy from the transponder than the other receiver coil. The transponder uses a coil to derive both a power source and a clock pulse from the high-intensity field for powering and driving an identification circuit.

Abstract: An improved automated method for the manufacture of alternatively sized passive transponder devices is presented which utilizes a single leadframe design and manufacturing process, including automated coil winding and wire-to-lead termination. A specially designed leadframe is prepared, with augmented leads, and is coated with a thin layer of silver. One or more semiconductor chips are bonded to individual assembly sites on the leadframe, after which the lead-die assembly is encapsulated by transfer molding. The cap and leads are singulated, and a bobbin is attached to the leads, which extend laterally from each individual molded cap. In an automated process, a conductive wire is attached to a first of the protruding leads, fly-wound around the bobbin core, and terminated by connection to a second of the protruding leads.

Abstract: An improved automated method for the manufacture of small implantable passive transponder devices is presented in which semiconductor wafer die are bonded to a conductively coated tape leadframe. This tape, with die attached, is injected molded to form a cap around the leads and the attached die, such that the exposed portion of the leads extend laterally from the cap. A ferrite core is attached to the base of the cap, and a fine coil wire, dispensed from a specially designed applicator, is automatically bonded to one of the leads protruding from the cap body. The wire is subsequently wound around the ferrite core and terminated by automatic attachment to another of the protruding leads. The assembled device is thereafter encapsulated within a small glass housing.

Abstract: An electromagnetic transmission and detection apparatus comprising a transmission coil (20) for producing a high intensity electromagnetic field including one or more conductive windings (24) circumscribing a substantially polygonal volume of space having a central axis, and first and second receiver coils (22) disposed within the polygonal volume of space for receiving a low-intensity electromagnetic field transmitted from an external source. The receiver coils (22) are co-planar with the transmitter coil (20) and are disposed within the polygonal volume of the transmitter coil at positions which are polygonally, diametrical opposed to one another. The receiver coils (22) are electrically connected to each other in a differential circuit relationship such that the magnitude of electrical signals induced in the receiver coils (22) by uniform electromagnetic energy are substantially equal and opposite to one another.

Abstract: This invention is directed to composite coating for maintaining low moisture levels at the surface of solid substrates. One embodiment of the invention comprises a coating having a desiccant layer between layers of the same or different elastomeric polymers. Another embodiment comprises a layer of elastomeric polymer covered with a layer of an elastomeric polymer/desiccant mixture. The composite coating may be applied to integrated circuits to prevent corrosion thereof.

Abstract: This invention is directed to composite coating for maintaining low moisture levels at the surface of solid substrates. One embodiment of the invention comprises a coating a having a desiccant layer between layers of the same or different elastomeric polymers. Another embodiment comprises a layer of elastomeric polymer covered with a layer of an elastomeric polymer/desiccant mixture. The composite coating may be applied to integrated circuits to prevent corrosion thereof.