Patents by Inventor Andreas Schulenberg

Andreas Schulenberg 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).

  • Patent number: 4984576
    Abstract: A circuit for heartbeat detection derives the heartbeat frquency from ultrasonic signals reflected from the heart and frequency-shifted due to the Doppler effect. The circuit allows for the automatic determination of the distance between the heart and an ultrasonic transducer located on the body of the patient, so that the evaluation of the reflected ultrasonic signals can be limited to a small body range and spurious signals from other ranges can be suppressed. The circuit comprises at least two channels which are enabled by a transmitting/receiving control circuit during receiving intervals for receiving and further processing the reflected ultrasonic signals. The receiving intervals of the different channels are time shifted toward one another so that the respectively received ultrasonic signals originate from different depth ranges within the body.
    Type: Grant
    Filed: November 2, 1989
    Date of Patent: January 15, 1991
    Assignee: Hewlett-Packard Company
    Inventors: Andreas Schulenberg, Martin Schraag