Northeast Monitoring

Electronics for Medicine, Inc.

Mortara Instrument, Inc.

Cardiodata Inc.

Mark Hubelbank

David Shadmon

Charles L Feldman

Mark J Leverault

Eric Goodrich

Electrode adapter

Electrode patch

Connected electrode patch

In one aspect, the invention is a method for processing pulse oxymetry data signals. The method includes recording pulse oxymetry data signals. The pulse oxymetry data signals have a plurality of oxymetry waveforms. The method also includes determining a correlation coefficient between sequential oxymetry waveforms and identifying a valid pulse oxymetry waveform.

Pulse oxymetry data processing

A portable machine records electrocardiographic signals and oxygen saturation signals in a removable memory device provided by an oxygen saturation sensor attached to a patient and patient lead wires with electrodes attached to the patient.

Electrocardiographic and oxygen saturation signal recording

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. From that elapsed time, the microprocessor calculates the impedance of the electrode channel being monitored. In addition, in response to the signal appearing at the output of the high range section of the dual range filtering stage, the microprocessor verifies contemporaneously the integrity of the electrode leads in order to validate the measured impedance value.

Automatic electrode channel impedance measurement system for egg monitor

A method and apparatus for digitally storing episodic signals, such as, electrocardiogram signals is disclosed. In a preferred embodiment, the apparatus includes, for each signal channel, an input amplifier, an analog-to-digital converter, and a double data buffer. The incoming signal on each channel is converted to a multibit digital number a fixed sampling rate. Each multibit digital number is stored in a location in the double data buffer. When a fixed amount of data is stored in the buffer, a processor examines the data to determine the periods during which the signal is undergoing the most rapid rate of change. For these periods, both an indicator of the period, and a first number of data samples per unit time is stored in a bulk solid state memory. Preferably, the data stored is a number relating to the difference between the value of the sample and a number related to the value of the last sample. For other periods, having rates of data change high, but not as high as those of the first period, a smaller number of samples per unit time is stored. These samples are chosen to faithfully reproduce the minima and maxima of the waveform. For all other waveform periods, every Rth sample is stored. The storage media is preferrably dynamic random access memory, the refresh rate of which is determined by the temperature of the circuitry.

Apparatus and method for solid state storage of episodic signals

In an electrocardiographic system there is a multielement electrode at two skin locations for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other. Parallel ECG signals are obtained from different elements of two multielement electrodes. The difference between the signals is detected by logical circuitry to produce a signal indicating baseline shift.

Apparatus and method for ECG baseline shift detecting

In an electrocardiographic system there is a multielement electrode at each skin location for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other; thus, events causing a baseline shift will also cause a difference in potential between the two elements of a multielement electrode. That difference is detected by logical circuitry to produce a signal indicating baseline shift.

Growing community of inventors

Sudbury, MA, United States of America

Mark Hubelbank