Patents by Inventor James W. Chong

James W. Chong has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Inductive plethysmographic transducers and electronic circuitry therefor
    Patent number: 5331968
    Abstract: The present invention is an apparatus and method for improving the detection of the inductance "signal" generated by an inductive plethysmograph (12). Signal detection is improved by modifying the design of the inductive plethysmograph (12) and also by improving the design of the associated circuitry. By virtue of these improvements, the associated circuitry may be located remotely rather than on the transducer, as is the current practice. In one aspect of the invention, the impedance matching transformer (14) joining the inductive plethysmograph (12) to the oscillator (16) is selected such that the inductance of its primary winding is greater than about ten times the reflected inductance of the inductive plethysmograph (12) and the cable (24) joining it to the transformer (14). In accordance with another aspect of the invention, the inductive plethysmograph (12) is modified such that the conductor (20) incorporated therein encircles the relevant body portion a plurality of times.
    Type: Grant
    Filed: March 10, 1993
    Date of Patent: July 26, 1994
    Inventors: Gerald Williams, Herman Watson, Marvin A. Sackner, Chu Pak, James W. Chong