Methods and apparatus for ambulatory physiological monitoring

• US 5,228,450 A
• Filed: 05/03/1991
• Issued: 07/20/1993
• Est. Priority Date: 05/03/1991
• Status: Expired due to Fees

• Current Assignee: Burdick, Inc. (OSI Systems Incorporated)
• Original Assignee: Diagnostic Medical Instruments, Inc. (OSI Systems Incorporated)
• Inventors: Sellers, Craig S.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US07/695,600
• Time in Patent Office: 809 Days
• Field of Search: 128/689, 128/696, 128/702, 128/710, 128/711, 128/712, 128/715, 128/419 PT, 364/413.06, 364/413.02, 364/413.03
• US Class Current: 600/524
• CPC Class Codes: A61B 5/303 Patient cord assembly, e.g. cable harness
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/332 Portable devices specially adapted therefor
• CPC Class Codes: A61B 5/336 Magnetic recording apparatus

Abstract

An ambulatory physiological monitor includes an input for receiving physiological data such as electrocardiography (ECG) data from a patient. This data is transferred to a disk drive by a processor or other suitable hardware. The disk drive records this data on the disk recording medium. The data is stored in noncompressed form. Preferably, to conserve power in the monitor, a buffer is also provided. The buffer temporarily holds the incoming data until the buffer is full. When the buffer is full, the disk drive is activated, and the contents are forwarded to the disk drive for storage on the disk recording medium. The monitor is switched from a low resolution mode to a high resolution mode in response to activation of an event button or at predetermined intervals.

Claims

1. A method for ambulatory recording of physiological data from a patient, said physiological data being used for subsequent medical diagnosis, comprising the steps of:

attaching an ambulatory physiological monitor containing a high capacity, miniaturized magnetic disk storage unit to an ambulatory patient;

obtaining physiological data from the patient while the patient is ambulatory using said ambulatory physiological monitor;

storing the physiological data in said disk storage unit while the patient is ambulatory; and

detaching said ambulatory physiological monitor from the ambulatory patient and transferring said physiological data from said disk storage unit to an external system for analysis and medical diagnosis.

2. An ambulatory physiological monitor for recording physiological data from a patient for subsequent medical diagnosis of the patient, comprising:

transducer means for attachment to an ambulatory patient for sensing at least one physiological parameter of the ambulatory patient and providing a physiological signal representative of the physiological parameter;

storage means for storing physiological data, said storage means comprising a high capacity, miniaturized magnetic disk storage unit;

circuit means for converting said physiological signal to physiological data, for transferring said physiological data to said disk storage unit, and for transferring said physiological data from said disk storage unit to an external system for subsequent analysis and medical diagnosis;

a housing containing said disk storage unit and said circuit means; and

means for attaching said housing to the ambulatory patient so that the patient is ambulatory during sensing and storage of physiological data.

3. An ambulatory physiological monitor as defined in claim 2 wherein said circuit means includes a buffer memory for temporary storage of said physiological data, means for transferring said physiological data from said buffer memory to said disk storage unit during spaced apart intervals, and means for energizing said disk storage unit only during said spaced apart intervals.

4. An ambulatory physiological monitor as defined in claim 3 wherein said buffer memory includes means for acquiring physiological data without interruption as physiological data is transferred from said buffer memory to said disk storage unit.

5. An ambulatory physiological monitor as defined in claim 2 wherein said circuit means includes means for sampling said physiological signal at a sampling rate of at least 200 samples per second to provide said physiological data and wherein said disk storage unit has sufficient capacity to record at east 24 hours of continuous, uncompressed physiological data.

6. An ambulatory physiological monitor as defined in claim 2 wherein said circuit means includes means for sampling said physiological signal at a first rate in a high resolution mode to provide high resolution physiological data, means for sampling said physiological signal at a second rate that is lower than said first rate in a low resolution mode to provide low resolution physiological data and means for selecting said high resolution mode or said low resolution mode.

7. An ambulatory physiological monitor as defined in claim 6 wherein said first rate is greater than 800 samples per second and said second rate is at least 200 samples per second.

8. An ambulatory physiological monitor as defined in claim 6 further including an event button that can be activated by the patient and wherein said means for selecting said high resolution mode or said low resolution mode includes means for selecting said high resolution mode in response to activation of said event button.

9. An ambulatory physiological monitor as defined in claim 6 wherein said means for selecting said high resolution mode or said low resolution mode includes means for automatically selecting said high resolution mode at predetermined intervals.

10. An ambulatory electrocardiography monitor for recording electrocardiography data from a patient, comprising:

a plurality of electrocardiography electrodes for attachment to an ambulatory patient for providing electrocardiography signals;

storage means for storing electrocardiography data, said storage means comprising a high capacity, miniaturized magnetic disk storage unit;

circuit means for converting said electrocardiography signals to electrocardiography data, for transferring said electrocardiography data to said disk storage unit, and for transferring said electrocardiography data from said disk storage unit to an external system for subsequent analysis and medical diagnosis;

a housing containing said disk storage unit and said circuit means; and

means for attaching said housing to said ambulatory patient so that the patient is ambulatory during sensing and storage of electrocardiography data.

11. An ambulatory electrocardiography monitor as defined in claim 10 wherein said circuit means includes a buffer memory for temporary storage of said electrocardiography data, means for transferring said electrocardiography data from said buffer memory to said disk storage unit during spaced apart intervals, and means for energizing said disk storage unit only during said spaced apart intervals.

12. An ambulatory electrocardiography monitor as defined in claim 10 wherein said circuit means includes means for sampling said electrocardiography signals at a sampling rate of at least 200 samples per second to provide said electrocardiography data and wherein said disk storage unit has sufficient capacity to record at least 24 hours of continuous, uncompressed electrocardiography data.

13. An ambulatory electrocardiography monitor as defined in claim 10 wherein said circuit means includes means for detecting pacemaker pulses in said electrocardiography signals, and means for separately storing the times of said pacemaker pulses on said disk storage unit.

14. An ambulatory electrocardiography monitor as defined in claim 13 further including an event button that can be activated by the patient and wherein said circuit means further includes means for recording the time of activation of said event button on said disk storage unit.

15. An ambulatory electrocardiography monitor as defined in claim 10 wherein said circuit means includes means for sampling said electrocardiography signals at a first rate in a high resolution mode to provide high resolution electrocardiography data means for sampling said electrocardiography signals at a second rate that is lower than said first rate in a low resolution mode to provide low resolution electrocardiography data and means for selecting said high resolution mode or said low resolution mode.

16. An ambulatory electrocardiography monitor as defined in claim 10 further including a self-contained power supply for powering said monitor.

17. A method for recording physiological data from an ambulatory patient for subsequent medical diagnosis of the patient, comprising the steps of:

attaching a transducer to an ambulatory patient;

sensing at least one physiological parameter of the ambulatory patient with the transducer and providing a physiological signal representative of the physiological parameter;

attaching to the ambulatory patient a housing containing a high capacity, miniaturized magnetic disk storage unit and a circuit, said circuit performing the steps of converting said physiological signal to physiological data and storing said physiological data in said disk storage unit, said housing being worn by the ambulatory patient during sensing and storage of physiological data; and

subsequently detaching said housing from the ambulatory patient and transferring said physiological data from said disk storage unit to an external system for analysis and medical diagnosis.

18. A method as defined in claim 17 wherein the step of storing said physiological data includes the steps of temporarily storing said physiological data in a buffer memory, transferring said physiological data from said buffer memory to said disk storage unit during spaced apart intervals, and energizing said disk storage unit only during said spaced apart intervals.

19. An ambulatory electrocardiography monitor for recording electrocardiography data from a patient, comprising:

a plurality of electrocardiography electrodes for attachment to an ambulatory patient for providing electrocardiography signals;

storage means for storing electrocardiography data;

circuit means for converting said electrocardiography signals to electrocardiography data, for transferring said electrocardiography data to said storage means, and for transferring said electrocardiography data from said storage means to an external system for subsequent analysis and medical diagnosis, said circuit means including means for sampling said electrocardiography signals at a first rate in a high resolution mode to provide high resolution electrocardiography data, means for sampling said electrocardiography signals at a second rate that is lower than said first rate in a low resolution mode to provide low resolution electrocardiography data and means for selecting said high resolution mode or said low resolution mode;

a housing containing said storage means and said circuit means; and

means for attaching said housing to the ambulatory patient so that the patient is ambulatory during sensing and storage of electrocardiography data.

20. An ambulatory electrocardiography monitor as defined in claim 19 wherein said storage means comprises a high capacity, miniaturized magnetic disk storage unit.

21. An ambulatory electrocardiography monitor as defined in claim 19 wherein said first rate is greater than 800 samples per second and said second rate is at least 200 samples per second.

22. An ambulatory electrocardiography monitor as defined in claim 21 further including an event button that can be activated by the patient and wherein said means for selecting said high resolution mode or said low resolution mode includes means for selecting said high resolution mode in response to activation of said event button.

23. An ambulatory electrocardiography monitor as defined in claim 21 wherein said means for selecting said high resolution mode or said low resolution mode includes means for automatically selecting said high resolution mode at predetermined intervals.