Cardiac monitoring apparatus and method

• US 20040077954A1
• Filed: 12/09/2002
• Published: 04/22/2004
• Est. Priority Date: 10/18/2002
• Status: Active Grant

• Current Assignee: Camntech Limited
• Original Assignee: Cambridge Neurotechnology Limited
• Inventors: Oakley, Nigel R., Ungless, Gary S.
• Granted Patent: US 6,881,191 B2
• Time in Patent Office: Days
• US Class Current: 600/483
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/335 using integrated circuit memory devices
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured

Abstract

A monitor includes cardiac and movement sensors 36, 34 responsive to a user'"'"'s heart beat and a user'"'"'s movement. The monitor includes a processor coupled to the sensors for generating heart-rate or other cardiac data and user movement or activity data. These data can be stored in a memory and used to analyse the relationship between heart rate and physical exertion.

Claims

1. A monitor for monitoring a user'"'"'s heart, comprising;

a cardiac sensor;

an accelerometer;

a support means for securing the cardiac sensor and the accelerometer in position for sensing the user'"'"'s heart beat and movement; and

a processor coupled to the cardiac sensor and the accelerometer for generating cardiac and movement data.

2. A monitor according to claim 1, in which the cardiac sensor is couplable to adhesive electrocardiogram (ECG) electrodes.

3. A monitor according to claim 2, in which the support means is couplable to one of the ECG electrodes.

4. A monitor according to claim 3 in which the ECG electrode is a standard ECG electrode having an electric contact, and the monitor clips to the electric contact both to provide an electrical input to the cardiac sensor and physically to support the monitor.

5. A monitor according to claim 1, comprising a memory coupled to an output of the processor for storing the cardiac and movement data.

6. A monitor according to claim 1, in which the processor generates inter-beat interval data from signals it receives from the cardiac sensor.

7. A monitor according to claim 1, in which the processor processes signals it receives from the cardiac sensor according to a predetermined parameter in order to generate the cardiac data and modifies that parameter in response to signals it receives from the accelerometer.

8. A monitor according to claim 1, in which a parameter, such as a gain parameter or a threshold voltage, used in deriving the cardiac data from an output of the cardiac sensor is variable in response to an output from the accelerometer or a movement or activity parameter derived therefrom.

9. A monitor according to claim 1, comprising contacts for making electrical contact with two ECG electrodes, in which the same contacts are couplable to an interface for transferring data from and/or to the monitor, and/or for resetting or reprogramming the monitor, and/or for recharging a battery for powering the monitor.

10. A monitor according to claim 1, in which the monitor in use is secured to the chest or torso of the user so that the accelerometer is oriented to sense vertical movements of the user'"'"'s chest or torso.

11. A monitor according to claim 1, which is of small size and weight so as to be comfortable for a user to wear for extended data sampling periods.

12. A method for monitoring a user'"'"'s heart, comprising the steps of;

sensing the user'"'"'s heart beat by means of a cardiac sensor secured to the user'"'"'s body;

sensing movement of the cardiac sensor;

processing cardiac and movement signals to generate cardiac and movement data; and

storing or displaying the data.

13. A method according to claim 12, comprising the step of housing the cardiac sensor and a movement sensor in a monitor and coupling the monitor to ECG electrodes secured to the user'"'"'s body.

14. A method according to claim 13, in which the step of coupling the monitor to one of the ECG electrodes also mechanically supports the apparatus on the electrode.