Johns Hopkins University

Noise Cancellation Technologies, Inc.

Dexter G Smith

Protagoras N Cutchis

Harvey Wayne Ko

Eldon W Ziegler, Jr

William P Wiesmann

Michael J Parrella

Carl V Nelson

Michael P McLoughlin

Charles W Kerechanin, Ii

Daniel G Jablonski

Loland Alex Pranger

David M White

William R Allmon

Jennifer A Nix

Douglas A Oursler

Joseph Schwartz

Michael F Arnold

Christopher P Nowicki

Michael P Boyle

An electromagnetic bioimpedance measurement apparatus uses an alternating magnetic field to induce electrical eddy currents in biological tissue. The eddy currents produce secondary magnetic fields that have the effect of changing the mutual inductance between the tissue and the coil that applied to the initial magnetic field. The amplitude of the resultant voltage, as measured by the same coil or a different receiver coil, is proportional to the conductivity of the tissue. A simple, marginally stable oscillator circuit is used to generate the current into the coil. Nearfield holographic signal processing is then used for holographic image formation. Bioimpedance is used to distinguish between normal tissue and cancerous tissue, especially cancerous prostate tissue. An invasive embodiment includes driven needle electrodes that are inserted into the body segment to be tested. Noninvasive embodiments include single or multiple coils arranged on a probe shaft.

Apparatus for sensing human prostate tumor

A portable ventilator for providing an air-recipient with compulsory respiration is provided with an outlet manifold and a single-expansion-chamber muffler configured so that airflow through an inhale outlet port of the muffler is pulse-free and a transmission loss, defined as the ratio of sound power generated by the at least one compressor and incident on the muffler to the sound power transmitted by the muffler, is sufficient to deaden the sound power of the compressor.

Portable ventilator

A time-domain electromagnetic target discriminator (ETD) sensor system and method are provided capable of measuring a metal target's time decay response based on the physical parameters of the metal target and its environment and for identifying the metal target. The ETD sensor system includes a pulse transmitter connected to a receiver via a data acquisition and control system. The transmitter and receiver include coil configurations for placement in proximity to a visually obscured, e.g., buried, metal target (or underground void) for inducing eddy currents within the metal target. The ETD sensor system measures the eddy current time decay response of the metal target in order to perform target recognition and classification. The identification process entails comparing the metal target's (or, underground void or other object's) time decay response with a library of normalized object signatures, e.g., time decay responses and other characteristics.

Electromagnetic target discriminator sensor system and method for detecting and identifying metal targets

An emergency life support system including a patient ventilator for mechanical breathing assistance; a capnograph to monitor COfor ventilation effectiveness; a pulse oximeter for measuring blood stream oxygen saturation; a carbon dioxide sensor; an electrocardiograph (ECG) to monitor cardiac performance; an infusion pump; and alarms and a data recorder. The preferred embodiment uses an oxygen generator to deliver oxygen, to generate electric power to run the ventilation system, and to warm IV fluids and resuscitated air. The generator has electronically controlled valves and a modified valve system that offers the ability to select the oxygen concentration in the air delivered to the patient.

Emergency life support system

A harmonic radar nonlinear junction detector system for detecting concealed weapons, electronics, and other man-made objects utilizing state-of-the art wireless technology, circuit fabrication, signal synthesis, and computer processing techniques to detect and characterize man-made objects possessing nonlinear junctions. The system transmits a pair of low power waveforms and a receiver within the system is coherently tuned to harmonics of the transmitted frequencies of the waveforms to detect man-made metal objects and electronics that contain non-linear junctions. The receiver is also capable of receiving inter-modulation products reflected from the man-made objects that are a result of using two incident signals. The system uses two signal sources generating user-definable waveforms of variable frequencies in order to provide enhanced discrimination and target identification abilities via the processing of returned inter-modulation products.

System and method of radar detection of non-linear interfaces

A low-pressure valve enabling precise control of a fluid flow rate through the valve during cyclical operation of the valve. The valve is useful for controlling air delivery to a patient as part of a portable ventilator. The valve comprises a housing having an inlet and two outlets and . A wiper plate and an orifice plate are disposed inside of the housing. Transverse movement of the wiper plate relative to the orifice plate , powered for example by a servomotor , simultaneously and alternatively covers and uncovers various openings in the orifice plate . The total flow through the valve is thereby divided between the two outlets and

Low-pressure valve

An active attenuation system for a DC motor which yields global vibration reduction of slot or other motor induced tonals at the plate on which the motor is mounted without modifying the construction of the motor. The system comprises one or more vibration sensors, a signal synchronized to the slot rate or other motor induced tonal rate, an electronic adaptive controller and the means to supply the control signal into the motor field and/or armature current.

Electronic cancellation of DC motor noise

Multiple source self noise cancellation

Low cost controller

An ultra quiet vacuum cleaner having a bag cavity (44), a motor/blower chamber (48) connected to said cavity by a flexible coupling (47) and an active, adaptive noise cancellation controller (52) so configured to quiet the exhaust of the air used to cool the motor/blower unit. Fast compensation and feedback compensation allow use of a straight, short duct (51) for superior cancellation performance.

Growing community of inventors

Columbia, MD, United States of America

Dexter G Smith