Pulse oximetry relational alarm system for early recognition of instability and catastrophic occurrences

• US 20050240091A1
• Filed: 06/09/2005
• Published: 10/27/2005
• Est. Priority Date: 08/19/1992
• Status: Active Grant

• Current Assignee: Lawrence A. Lynn
• Original Assignee: Lawrence A. Lynn
• Inventors: Lynn, Lawrence A.
• Granted Patent: US 7,398,115 B2
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 2560/0271 using a remote monitoring unit
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/087 Measuring breath flow
• 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 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• 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: A61H 2230/205 partial CO2-value
• CPC Class Codes: A61H 31/02 "Iron-lungs" , i.e. involving chest expansion by applying underpressure thereon, whether or not combined with gas breathing means

Abstract

A relational pulse oximetry alarm system and method is presented for earlier identification of the occurrence of an adverse clinical event. The system includes a pulse oximeter based microprocessor alarm system which provides an alarm based on a relational conformation of a plurality of time series and further based on the recognition of specific dynamic patterns of interaction between a plurality of corresponding and related time series including the occurrence of pathophysiologic divergence of two or more time series outputs. The processor is programmed to compare a first time series to a second time series to produce a comparison result, to identify a relationship between the first time series and the second time series, to identify a relational threshold breach, and to output an alarm based on the relational threshold breach. The system can include an oximeter testing system for predicting the timeliness of the response of the alarm of a pulse oximeter to the occurrence of an adverse clinical event.

Claims

1. ) A pulse oximeter based hospital microprocessor alarm system for the recognition of specific dynamic patterns of interaction between a plurality of corresponding and related time series, the system comprising a processor, the processor programmed to;

a) process a first time series to produce to identify a first primary threshold breach based on said first time series,

b) process a second time series,

c) compare at least a portion of said first time series to said second time series to produce a comparison result,

d) identify a relationship between said first time series and said second time series to identify a relational threshold breach.

e) output an alarm based on at least one of said primary and said relational threshold breaches.

2. ) An oximeter testing system for testing an oximeter having an alarm, said alarm defining an initial time of onset in response to a clinical adverse event, and for testing the timeliness of said time of onset in response to said clinical adverse event, the system comprising;

a) a processor programmed to;

generate an output indicative of a time series of oxygen saturation values, said output simulating the time series of oxygen saturation values associated with clinical occurrence of an adverse clinical event, said occurrence having a time of onset, and to,

calculate the difference between said time of onset of said occurrence and said time of onset of said alarm.

b) an oxygen saturation simulator for presenting said output to said oximeter, so that the delay between the onset of said occurrence and the occurrence of said alarm can be determined.

3. ) The system of claim 2 wherein said simulated occurrence is a respiratory arrest.

4. ) The system of claim 2 wherein said simulated occurrence is a respiratory arrest occurring with the lung volume at functional residual capacity at the time of onset of said occurrence.

5. ) The system of claim 2 wherein said simulated occurrence is a respiratory arrest occurring with the alveolar oxygen concentration at about 21% at the time of onset of said occurrence.

6. ) The system of claim 2 wherein said processor is programmed to identify the time of onset of said alarm of said oximeter.

7. ) The system of claim 2 wherein said processor is programmed to measure the difference between said time of onset of said occurrence of said clinical adverse event and the time of onset of said alarm.

8. ) The system of claim 2 wherein said processor is programmed to output an indication of said difference.

9. ) The system of claim 2 wherein said processor is programmed to output said difference.

10. ) The system of claim 2 wherein said oximeter includes a probe, said simulator including a member for interfacing with said probe, said member capable of presenting a secondary dynamic variation simulating a primary dynamic variation in oxygen saturation, said variation being based on said output, said processor presenting said output to said member, said member presenting said dynamic variation to said probe.

11. ) The system of claim 2 further including a audio sensor for automatically detecting the occurrence of said alarm.