Patents Assigned to Mortara Instrument
  • Patent number: 5197479
    Abstract: An impedance measurement system for electrocardiographic recorders which allows measurement of the electrode channel impedance without the need for a separate piece of equipment. The impedance measurement system, which is an integral part of the recorder, applies complementary oscillating currents having short transition times to an electrode channel defined by a pair of electrode leads, a pair of electrodes and the patient tissues. The analog current signals flowing through the electrode channel create a voltage across the electrode channel which is amplified and applied to a dual range filtering stage. The low range section of the dual range filtering stage generates a time-dependent signal which causes the output of the low range filtering circuit to produce a signal applied to the timing input of a microprocessor. The microprocessor calculates the time elapsed between each transition of the oscillating current signals and the occurrence of a signal at the output of the low range filtering circuitry.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: March 30, 1993
    Assignee: Mortara Instrument
    Inventors: Mark Hubelbank, David Shadmon, Mark J. Leverault
  • Patent number: 4951681
    Abstract: Disclosed herein is a method and apparatus employing a D.C. drive motor and digital printhead for recording electrocardiographic data or other digital data on a chart at a constant time scale, regardless of temporary variations in the D.C. motor speed. A buffer memory stores sensed digital ECG data, and a data count register provides a count indicative of the amount of data stored. A pulse width register controls the width of long and short pulses generated by a motor driver for the selected paper speed. An experience count register has a count indicative of the relative number of long and short pulses generated. The original or current width of the pulses may be adjusted by the pulse width register, subject to the count of the experience count register, for controlling the speed of the D.C. drive motor. The motor speed is increased if the buffer memory is storing more than a preselected amount of data, and the motor speed is decreased if the buffer memory is storing less than a preselected amount of data.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: August 28, 1990
    Assignee: Mortara Instrument
    Inventor: David W. Mortara
  • Patent number: 4630204
    Abstract: A waveform processor for processing waveforms of the ECG type from surface electrodes connected to the human body. Differential lead waveforms are sampled by a fast, high resolution A/D converter which are thereafter provided to a preprocessor where filtering and a reconstruction of the leads waveforms takes place. The waveforms are then detected, classified, and averaged to form composites of the X, Y, and Z terminal leads. Special filtering is used to detect the high frequency low amplitude features of the composite waveforms.
    Type: Grant
    Filed: February 21, 1984
    Date of Patent: December 16, 1986
    Assignee: Mortara Instrument Inc.
    Inventor: David W. Mortara
  • Patent number: D326716
    Type: Grant
    Filed: February 22, 1990
    Date of Patent: June 2, 1992
    Assignee: Mortara Instrument
    Inventor: David W. Mortara