Medical diagnostic apparatus with sleep mode

• US 5,924,979 A
• Filed: 08/28/1997
• Issued: 07/20/1999
• Est. Priority Date: 02/09/1996
• Status: Expired due to Term

• Current Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Inventors: Luecke, James E., Nootbaar, Michael W., Swedlow, David B., Porges, Charles E., Bernstein, Michael J.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US08/919,540
• Time in Patent Office: 691 Days
• Field of Search: 600/300, 600/310, 600/322, 600/323, 600/324, 600/326, 600/333, 600/336, 600/483, 607/16
• US Class Current: 600/300
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/02 Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method and apparatus for conserving power in a medical diagnostic apparatus by using a sleep mode during a monitoring state. The sleep mode allows not only the processor to be put to sleep, but other detection circuitry as well. This is accomplished by not relying on detecting events to awaken the sleeping circuitry, but rather establishing the stability of a physiological parameter before going to sleep. The invention monitors a physiological parameter of the patient and enters a sleep mode only after it has been stable for a predetermined period of time. The apparatus is periodically awakened from the sleep mode to take additional measurements and to ascertain that the stability of the physiological parameter has not changed. In one embodiment, the sleep period is chosen to be consistent with the period in which an alarm condition would need to be generated if a patient'"'"'s condition started to quickly change.

Claims

1. A method for conserving power in a medical diagnostic apparatus, said apparatus including a processor and a memory, the method comprising the steps of:

(a) measuring a first physiological parameter of a patient using said apparatus;

(b) storing data reflecting said measuring of the first physiological parameter in said memory;

(c) processing said data using said processor; and

(d) putting said processor in a sleep mode when an amount of data in said memory is below a predetermined level.

2. The method of claim 1 wherein said apparatus is a pulse oximeter, and further comprising the steps of:

operating an emitter and an associated drive circuit, and a detector and an associated data collection circuit during at least a portion of the time said processor is in the sleep mode.

3. The method of claim 1 further comprising:

awakening said processor when an amount of data in said memory is greater than a first value.

4. A medical diagnostic apparatus comprising:

a processor;

a memory coupled to said processor;

means for measuring a first physiological parameter of a patient and storing measurement data in said memory; and

means for putting said processor in a sleep mode when an amount of data in said memory is below a predetermined level.

5. The apparatus of claim 4 wherein said apparatus is a pulse oximeter, and further comprising:

an emitter;

a drive circuit connected to said emitter;

a detector;

a data collection circuit connected to said detector and said memory; and

means for operating said emitter, said drive circuit, said detector and said data collection circuit during at least a portion of the time said processor is in the sleep mode.

6. The apparatus of claim 4 further comprising:

means for awakening said processor when an amount of data in said memory is greater than a first value.

7. A method for conserving power in a medical diagnostic apparatus, said apparatus including electronic circuitry, the method comprising the steps of:

(a) measuring a first physiological parameter of a patient using said apparatus;

(b) monitoring a stability-indicating physiological parameter of said patient;

(c) determining when said stability-indicating physiological parameter has been stable for a predetermined stable time period and providing a stability indication signal;

(d) initiating a sleep mode for at least a portion of said electronic circuitry, in response to said stability indication signal, for a first, sleep portion of each of a plurality of sleep mode time periods;

(e) exiting said sleep mode for at least some of said portion of electronic circuitry for a second, awake portion of each of said plurality of sleep mode time periods;

(f) determining whether said stability indicating physiological parameter remains stable during at least periodic ones of said sleep mode time periods;

(g) repeating steps (a)-(f) if said stability-indicating physiological parameter is determined to not have remained stable during said awake portion; and

(h) repeating steps (c)-(f) if said stability-indicating physiological parameter is determined to have remained stable during said awake portion.

8. The method of claim 7 further comprising the steps of:

storing data reflecting said measuring of said first physiological parameter in a memory;

processing said data using a processor;

putting said processor in said sleep mode when an amount of data in said memory is below a predetermined level.

9. The method of claim 7 further comprising the step of controlling the initiation and exiting of said sleep mode with a remote host computer.

10. The method of claim 7 wherein said apparatus includes a display, and further comprising the steps of:

deactivating at least a portion of said display during said sleep mode.

11. The method of claim 7 further comprising the steps of:

determining whether said stability-indicating physiological parameter has been greater than a predetermined value during said stable time period; and

providing said stable indication signal only if said stability-indicating physiological parameter has been greater than said predetermined value during said stable time period.

12. The method of claim 7 further comprising the steps of:

providing an alarm signal in response to a pre-specified physiological condition of a patient or a condition of said apparatus continuing for an alarm time-out period; and

shortening said alarm time-out period upon exiting said sleep mode.

13. The method of claim 7 wherein said stability-indicating physiological parameter is monitored by a monitor other than said apparatus.

14. A medical diagnostic apparatus having electronic circuitry and a power saving feature, comprising:

means for measuring a first physiological parameter of a patient;

means, coupled to said apparatus, for monitoring at least one stability-indicating physiological parameter of said patient;

means, coupled to said means for monitoring, for determining when said stability-indicating physiological parameter has been stable for a predetermined stable time period and providing a stability indication signal;

means, coupled to said means for determining, for initiating a sleep mode for said at least a portion of said electronic circuitry, in response to said stability indication signal, for a first, sleep portion of each of a plurality of sleep mode time periods;

means for exiting said sleep mode for at least some of said portion of said electronic circuitry for a second, awake portion of each of said plurality of sleep mode time periods;

means for determining whether said stability-indicating physiological parameter remains stable during at least periodic ones of said sleep mode time periods; and

means for reinitiating said sleep portion if said stability-indicating physiological parameter is determined to have remained stable during said awake portion.

15. The apparatus of claim 14 further comprising:

a remote host computer; and

means for controlling the initiation and exiting of said sleep mode with said remote host computer.

16. The apparatus of claim 14 further comprising:

a display;

means for deactivating at least a portion of said display during said sleep mode.

17. The apparatus of claim 14 further comprising:

means for determining whether said stability-indicating physiological parameter has been greater than a predetermined value for said stable time period; and

means for providing said stable indication signal only if said stability-indicating physiological parameter has been greater than said predetermined value for said stable time period.