Cardiac monitoring system and method

• US 5,819,741 A
• Filed: 05/24/1996
• Issued: 10/13/1998
• Est. Priority Date: 10/07/1994
• Status: Expired due to Fees

• Current Assignee: Ortivus AB
• Original Assignee: Ortivus Medical AB
• Inventors: Karlsson, Per, Ubby, Johan, Oljemark, Michael, Lundahl, Gunilla
• Primary Examiner(s): Getzow, Scott M.
• Application Number:
  US08/653,448
• Time in Patent Office: 872 Days
• Field of Search: 128/696, 128/710, 128/731, 364/413.06
• US Class Current: 600/523
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/276 Protection against electrode failure
• CPC Class Codes: A61B 5/327 Generation of artificial ECG signals based on measured signals, e.g. to compensate for missing leads
• CPC Class Codes: A61B 5/341 Vectorcardiography [VCG]
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/366 Detecting abnormal QRS complex, e.g. widening
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick

Abstract

A cardiac monitoring method and system provides advanced ischemia and infarction analysis and monitoring. Advanced calculations are performed on ECG signals to obtain parameter values relating to myocardial ischemia and infarction. Dominant heart beats are averaged to form a smooth beat, which is analyzed to determine the parameter values continuously and in real-time. The result of each analyzed time interval is presented as points in a trend graph on a monitoring display. All calculations are performed on-line and the trend curves are updated immediately. Systems and methods for monitoring, analyzing, and/or diagnosing cardiac activity that display a state of signals received from leads attached to a patient on a graphic depiction of the patient are also provided. The graphic depiction of the patient may include electrode position information.

Claims

1. A system for monitoring, analyzing, and/or diagnosing the cardiac activity of a patient, comprising:

plurality of electrodes positioned at a respective plurality of locations on the patient for directing a respective plurality of electrical signals from the patient;

ECG data production means connected to the plurality of electrodes for acquiring said plurality of electrical signals directed by the plurality of electrodes and for producing ECG data in response to the acquired electrical signals;

display means connected to the ECG data production means for displaying a graphic depiction of at least part of the patient, the location, on the graphic depiction of at least part of the patient, of each of said plurality of electrodes, and a status of each of said electrical signals directed from said plurality of electrodes, wherein the status of each of said electrical signals directed from each of said plurality of electrodes includes at least one condition in which the electrical signal has a value such that the ECG production means is unable to produce a valid ECG signal in response thereto.

2. The system of claim 1, wherein said display means includes a plurality of electrode status indicators, each of said plurality of electrode status indicators being disposed on the graphical depiction of at least part of the patient at a position substantially corresponding to one of said plurality of locations on the patient at which one of said plurality of electrodes is positioned.

3. The system of claim 2, wherein said display means includes a plurality of electrode status annunciators, each of said plurality of electrode status annunciators being alphanumeric indicators and corresponding to at least one of said electrode status indicators.

4. The system of claim 3, wherein the status of each of said plurality of electrical signals directed from each of the plurality of electrodes further includes a first condition in which the electrical signal is out of the acquisition range of the ECG production means, a second condition in which the electrical signal is too noisy for the ECG production means to produce a proper ECG signal in response thereto, a third condition in which the electrical signal exhibits baseline drift, and a fourth condition in which the signal exhibits a spike, wherein each of said plurality of electrode status indicators produces a graphic output when the electrical signal corresponding thereto is in one of the first, second, third, or fourth conditions and each of said electrode status annunciators indicates which of said conditions the corresponding electrical signal is in.

5. The system of claim 4, wherein each of said electrode status annunciators is adapted to selectively display an impedance value of at least one of said plurality of electrodes.

6. The system of claim 2, wherein the status of each of said plurality of electrical signals directed from each of the plurality of electrodes further includes a first condition in which the electrical signal is out of the acquisition range of the ECG production means and a second condition in which the electrical signal is too noisy for the ECG production means to produce a proper ECG signal in response thereto, wherein each of said plurality of electrode status indicators produces a first graphic output when the electrical signal corresponding thereto is in the first condition and each of said electrode status indicators produces a second graphic output when the electrical signal corresponding thereto is in the second condition.

7. The system of claim 2, wherein said display means comprises a cathode ray tube.

8. The system of claim 2, wherein said display means comprises a plasma display.

9. The system of claim 2, wherein said display means comprises a liquid crystal display.

10. The system of claim 2, wherein said display means comprises an electroluminescent display.

11. The system of claim 1, wherein said display means includes a translucent overlay having a graphical depiction of at least part of the patient and a plurality of light production means disposed behind the translucent overlay, each of said plurality of light production means being disposed behind the transparent overlay at a position substantially corresponding to one of said plurality of locations on the patient at which one of said plurality of electrodes is positioned.

12. The system of claim 11, wherein each of said plurality of light production means is a light emitting diode.

13. The system of claim 12, wherein the status of each of said plurality of electrical signals directed from each of the plurality of electrodes further includes a first condition in which the electrical signal is out of the acquisition range of the ECG production means and a second condition in which the electrical signal is too noisy for the ECG production means to produce a proper ECG signal in response thereto, wherein each of said light emitting diodes produces a first light output when the electrical signal corresponding thereto is in the first condition and each of said light emitting diodes produces a second light output when the electrical signal corresponding thereto is in the second condition.

14. A method for monitoring, analyzing, and/or diagnosing the cardiac activity of a patient, comprising:

positioning a plurality of electrodes at a respective plurality of locations on the patient for directing a respective plurality of electrical signals from the patient;

acquiring said plurality of electrical signals by connecting ECG data production means to the plurality of electrodes;

producing ECG data in response to the acquired electrical signals; and

displaying on display means connected to the ECG production means the location, on the patient, of each of said plurality of electrodes and a status of each of said electrical signals, wherein the status of each of said electrical signal has a value such that the ECG data production means is unable to produce a valid ECG signal in response thereto.

15. The method of claim 14, wherein said display means includes a graphical depiction of at least part of the patient and a plurality of electrode status indicators, each of said plurality of electrode status indicators being disposed on the graphical depiction of at least part of the patient at a position substantially corresponding to one of said plurality of locations on the patient at which one of said plurality of electrodes is positioned.

16. The method of claim 15, wherein said display means includes a plurality of electrode status annunciators, each of said plurality of electrode status annunciators being alphanumeric indicators and corresponding to at least one of said electrode status indicators.

17. The method of claim 16, wherein the status of each of said plurality of electrical signals directed from each of the plurality of electrodes further includes a first condition in which the electrical signal is out of the acquisition range of the ECG production means, a second condition in which the electrical signal is too noisy for the ECG production means to produce a proper ECG signal in response thereto, a third condition in which the electrical signal exhibits baseline drift, and a fourth condition in which the signal exhibits a spike, wherein each of said plurality of electrode status indicators produces a graphic output when the electrical signal corresponding thereto is in one of the first, second, third, or fourth conditions and each of said electrode status annunciators indicates which of said conditions the corresponding electrical signal is in.

18. The method of claim 15, wherein the status of each of said plurality of electrical signals further includes a first condition in which the electrical signal is out of the acquisition range of the ECG production means and a second condition in which the electrical signal is too noisy for the ECG production means to produce a proper ECG signal in response thereto, wherein each of said plurality of electrode status indicators produces a first graphic output when the electrical signal corresponding thereto is in the first condition and each of said electrode status indicators produces a second graphic output when the electrical signal corresponding thereto is in the second condition.

19. The method of claim 14, wherein said display means includes a translucent overlay having a graphical depiction of at least part of the patient and a plurality of light production means disposed behind the translucent overlay, each of said plurality of light production means being disposed behind the transparent overlay at a position substantially corresponding to one of said plurality of locations on the patient at which one of said plurality of electrodes is positioned.

20. The method of claim 19, wherein each of said plurality of light production means is a light emitting diode.

21. The method of claim 20, wherein the status of each of said plurality of electrical signals further includes a first condition in which the electrical signal is out of the acquisition range of the ECG production means and a second condition in which the electrical signal is too noisy for the ECG production means to produce a proper ECG signal in response thereto, wherein each of said light emitting diodes produces a steady light output when the electrical signal corresponding thereto is in the first condition and each of said light emitting diodes produces a blinking light output when the electrical signal corresponding thereto is in the second condition.