System for and method of establishing monitoring alarm limits based on physiological variables

• US 6,585,645 B2
• Filed: 05/16/2001
• Issued: 07/01/2003
• Est. Priority Date: 05/16/2001
• Status: Active Grant

• Current Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Original Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Inventors: Hutchinson, George M.
• Primary Examiner(s): Pelham, Joseph
• Application Number:
  US09/858,808
• Publication Number:
  US 20020177755A1
• Time in Patent Office: 776 Days
• Field of Search: 600/300, 600/301, 600/529-539, 600/481-486, 600/500, 600/508, 340/573.1
• US Class Current: 600/300
• CPC Class Codes: A61B 5/02455 provided with high/low alarm devices
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

The invention relates to a system for and a method of establishing monitoring alarm limits based on physiological variables. Such a method can include the steps of receiving a plurality of physiological variable data where the physiological variable data is representative of physiological wellness variables, correlating alarm states of the physiological wellness variables with alarm states of physiological measurable variables, and providing a best clinical selection for the alarm limits.

Claims

1. A method of establishing monitoring alarm limits based on physiologic variables, the method comprising the steps of:

receiving a plurality of physiological variable data, the physiological variable data being representative of physiological wellness variables;

correlating alarm states of the physiological wellness variables with alarm states of physiological measurable variables; and

providing a best clinical selection for the alarm limits.

2. The method of claim 1, wherein the step of receiving a plurality of physiological variable data comprises communicating the physiological variable data from a computer storage medium containing matrices of numbers to a computing device.

3. The method of claim 1, wherein the physiological wellness variables comprise indications of a patient condition which are not easily measurable but can be calculated via models and the physiological measurable variables comprise indications of a patient condition which are more easily measurable.

4. The method of claim 1, wherein the step of correlating alarm states of the physiological wellness variables with alarm states of physiological measurable variables comprises establishing a set of limits for the physiological measurable variables based on a set of limits for the physiological wellness variables.

5. The method of claim 1, wherein the step of correlating alarm states of the physiological wellness variables with alarm states of physiological measurable variables comprises utilizing a Kappa statistic to determine agreement between the alarm states of physiological wellness variables and the alarm states of physiological measurable variables.

6. The method of claim 1, further comprising providing a weighted average of alarm limits and the correlated alarm states.

7. The method of claim 6, wherein the step of providing a weighted average of alarm limits and the correlated alarm states comprises utilizing the formula:

$L_{\mathrm{variable}}=\frac{\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>L_i\times <br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>a_i}{\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>a_i}$

where L_variable is the optimum alarm limit for all test situations, L_i is the optimum alarm limit for a single test situation, kappa_i is the kappa agreement for a single test situation and i is the particular test situation and n is a number of scenarios evaluated.

8. A computer implemented method of establishing alarm limits for a physiological monitor, the physiological monitor being configured to monitor measurable variables of a patient, the method comprising:

associating alarm states of wellness physiological variables with alarm states of measurable physiological variables;

providing a range of acceptable alarm limits based on the associated alarm states; and

selecting monitor alarm limits for a physiological monitor based on the provided range of acceptable alarm limits.

9. The computer implemented method of claim 8, wherein the step of associating alarm states of wellness physiological variables with measurable physiological variables comprises statistically comparing alarm limits for the wellness physiological variables with alarm limits for the measurable physiological variables.

10. The computer implemented method of claim 9, wherein the step of statistically comparing alarm limits for the wellness physiological variables with alarm limits for the measurable physiological variables comprises analyzing agreement between the wellness physiological variables and the measurable physiological variables with a Kappa statistic.

11. The computer implemented method of claim 8, wherein the step of providing a range of acceptable alarm limits based on the associated alarm states comprises analyzing agreement between alarm status data of wellness physiological variables.

12. The computer implemented method of claim 8, wherein the step of selecting monitor alarm limits for a physiological monitor based on the provided range of acceptable alarm limits comprises for each measurable physiological variable providing an alarm limit corresponding with a peak agreement of wellness physiological variables.

13. The computer implemented method of claim 12, wherein the range of alarm limits corresponds to an agreement of 80 percent of peak agreement of wellness physiological wellness variables.

14. A system for establishing monitoring physiological alarm limits based on physiological variables, the system comprising:

means for receiving a plurality of physiological variable data, the physiological variable data being representative of physiological wellness variables;

means for correlating alarm states of the wellness physiological wellness variables with alarm states of physiological measurable variables; and

means for providing a best clinical selection for the alarm limits.

15. The system of claim 14, wherein the means for receiving a plurality of physiological variable data comprises means for communicating the physiological variable data from a computer storage medium containing matrices of numbers to a computing device.

16. The system of claim 14, wherein the wellness physiological wellness variables comprise indications of a patient condition which are not easily measurable and the physiological measurable variables comprise indications of a patient condition which are more easily measurable.

17. The system of claim 14, wherein the means for correlating alarm states of the wellness physiological wellness variables with alarm states of physiological measurable variables comprises means for establishing a set of limits for the physiological measurable variables based on a set of limits for the wellness physiological wellness variables.

18. The system of claim 14, wherein the means for correlating alarm states of the wellness physiological wellness variables with alarm states of physiological measurable variables comprises means for utilizing a Kappa statistic to determine agreement between the wellness physiological wellness variables and the physiological measurable variables.

19. The system of claim 14, further comprising means for providing a weighted average of alarm limits and the correlated alarm states.

20. The system of claim 19, wherein the means for providing a weighted average of alarm limits and the correlated alarm states comprises utilizing the formula:

$L_{\mathrm{variable}}=\frac{\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>L_i\times <br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>a_i}{\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>a_i}$

where L_variable is the optimum alarm limit for all test situations, L_i is the optimum alarm limit for a single test situation, kappa_i is the kappa agreement for a single test situation and i is the particular test situation and n is a number of scenarios evaluated.

21. The system of claim 14, wherein one of the physiological wellness variables includes a partial pressure of oxygen in the brain, the partial pressure of oxygen in the brain correlating with a blood pressure physiological measurable variable.

22. A method of establishing monitoring alarm limits based on system variables, the method comprising the steps of:

receiving a plurality of system variable data, the system variable data being representative of system acceptability variables;

correlating alarm states of the system acceptability variables with alarm states of system measurable variables; and

providing a manufacture determined selection for the alarm limits.

23. The method of claim 22, wherein the step of receiving a plurality of system variable data comprises communicating the system variable data from a computer storage medium containing matrices of numbers to a computing device.

24. The method of claim 22, wherein the system acceptability variables comprise indications of a system condition which are not easily measurable but can be calculated via models and the system measurable variables comprise indications of a system condition which are more easily measurable.

25. The method of claim 22, wherein the step of correlating alarm states of the system acceptability variables with alarm states of system measurable variables comprises establishing a set of limits for the system measurable variables based on a set of limits for the system acceptability variables.

26. The method of claim 22, wherein the step of correlating alarm states of the system acceptability variables with alarm states of system measurable variables comprises utilizing a Kappa statistic to determine agreement between the alarm states of system acceptability variables and the alarm states of system measurable variables.

27. The method of claim 22, further comprising providing a weighted average of alarm limits and the correlated alarm states.

28. The method of claim 27, wherein the step of providing a weighted average of alarm limits and the correlated alarm states comprises utilizing the formula:

$L_{\mathrm{variable}}=\frac{\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>L_i\times <br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>a_i}{\underset{i=1}{\overset{n}{\sum <br><br>}}<br><br>k<br><br>\text{\hspace{1em}<br><br>}<br><br>a<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>p<br><br>\text{\hspace{1em}<br><br>}<br><br>a_i}$

where L_variable is the optimum alarm limit for all test situations, L_i is the optimum alarm limit for a single test situation, kappa_i is the kappa agreement for a single test situation and i is the particular test situation and n is a number of scenarios evaluated.

29. A computer implemented method of establishing alarm limits for a monitor, the monitor being configured to monitor measurable variables of a system, the method comprising:

associating alarm states of system acceptability variables with alarm states of system measurable variables;

providing a range of acceptable alarm limits based on the associated alarm states; and

selecting monitor alarm limits for a monitor based on the provided range of acceptable alarm limits.

30. The computer implemented method of claim 29, wherein the step of statistically comparing alarm limits for the system acceptability variables with alarm limits for the system measurable variables comprises analyzing agreement between the system acceptability variables and the system measurable variables with a Kappa statistic.

31. The computer implemented method of claim 29, wherein the step of providing a range of acceptable alarm limits based on the associated alarm states comprises analyzing agreement between alarm status data of system acceptability variables.

32. The computer implemented method of claim 29, wherein the step of selecting monitor alarm limits for a monitor based on the provided range of acceptable alarm limits comprises for each system measurable variable providing an alarm limit corresponding with a peak agreement of system acceptability variables.

33. The computer implemented method of claim 32, wherein the range of alarm limits corresponds to an agreement of 80 percent of peak agreement of system acceptability variables.