Patents by Inventor David W. Davies

David W. Davies 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: 4905707
    Abstract: A method is disclosed for monitoring the body reaction against a heart transplant. When a heart is newly transplanted, electrocardiac signals from the transplanted heart are detected. The analog signals are converted to digital signals. A first differentiation of the digital signals is carried out over a continuous time period to create reference differentiated signals. At a later time during monitoring of the transplanted heart, analog electrocardiac signals are again detected from the transplanted heart. These analog signals are converted to digital signals. A first differentiation is carried out of these digital signals over a continuous time period to create monitored differentiated signals. The reference differentiated signals and the monitored differentiated signals are compared at least with respect to amplitude to create comparison results. All of the above operations occur within the body.
    Type: Grant
    Filed: December 8, 1986
    Date of Patent: March 6, 1990
    Assignee: Siemens Aktiengesellschaft
    Inventors: David W. Davies, Bengt A. Lekholm
  • Patent number: 4905708
    Abstract: Apparatus for recognizing cardiac arrhythmias digitalises analog signals which are obtained when carrying out sensing at the heart or on the body and carries out a first differentiation of the digitalised signals. A gradient pattern detector compares the differentiated signals thereby produced with normal differentiated signals detected during sinus rhythm as to amplitude, polarity and sequence. Differences between the differentiated signals will be indicative of pathological tachycardias, the nature of which will be identified by comparison with pre-programmed signals of like type and a response to terminate the arrhythmia can be delivered to the heart.
    Type: Grant
    Filed: September 24, 1987
    Date of Patent: March 6, 1990
    Inventor: David W. Davies
  • Patent number: 4790317
    Abstract: For automatic recognition of ventricular tachycardia and ventricular fibrillation, pulse sequences are compared which are obtained when sensing at at least one position on each ventricular epicardial surface of a heart. Changes in the sequence of activations and in the timing from pulsing at one sensor position to a next pulsing at that same position will indicate both ventricular tachycardia and ventricular fibrillation so as to enable a response to be made to restore a pulse sequence representing normal ventricular activity of the heart.
    Type: Grant
    Filed: October 27, 1986
    Date of Patent: December 13, 1988
    Inventor: David W. Davies