Synchronization of measurement values

• US 5,807,245 A
• Filed: 11/27/1995
• Issued: 09/15/1998
• Est. Priority Date: 05/26/1994
• Status: Expired due to Term

• Current Assignee: Astra AB (Astrazeneca PLC)
• Original Assignee: Astra AB (Astrazeneca PLC)
• Inventors: Waldeck, Johan, Aldestam, Sten, Marnfeldt, Goran
• Primary Examiner(s): Bahr, Jennifer
• Assistant Examiner(s): HUANG, STEPHEN D
• Application Number:
  US08/563,199
• Time in Patent Office: 1,023 Days
• Field of Search: 128/630, 128/637, 128/638, 128/716, 128/720, 128/721, 128/723, 128/725-728, 128/737-733, 128/739-741, 128/920, 128/923, 128/901, 600/509
• US Class Current: 600/300
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: A61B 5/085 Measuring impedance of respiratory organs or lung elasticity
• CPC Class Codes: A61B 5/1104 induced by stimuli or drugs; A61B5/1102 takes precedence; investigating medicinal preparations G01N33/15
• CPC Class Codes: G01R 21/133 by using digital technique

Abstract

A measurement system including a first unit that obtains a first measurement value associated with a first time indication and a second measurement value associated with a second time indication and a second unit that comprises a processor and receives values asynchronously from the first unit, wherein the processor synchronizes the first and second measurement values using the first and second time indications.

Claims

1. A measurement system comprising

a first unit that obtains a first measurement value associated with a first time indication and a second measurement value associated with a second time indication;

and

a second unit that comprises a second-unit processor and receives values asynchronously from said first unit, wherein the second-unit processor synchronizes said first and second measurement values in real time using said first and second time indications.

2. The measurement system of claim 1, wherein

the first unit comprises a first-unit processor that performs a calculation using the first measurement value to generate a refined measurement value associated with a third time indication that is derived from the first time indication;

and

one of the values received by the second unit is the refined measurement value.

3. The measurement system of claim 2, wherein the refined value with the associated third time indication is used as the first measurement value with the associated first time indication when the second-unit processor performs the synchronization.

4. The measurement system of claim 1, wherein the first unit comprises

a sensor unit to obtain the first measurement value;

and

a channel unit comprising a processor for performing a calculation using the first measurement value.

5. The measurement system of claim 1, wherein the first unit further comprises a clock counter for determining the time indications.

6. The measurement system of claim 1, wherein

the first unit comprises a first memory and a processor;

the measurement system comprises a second memory which stores a program usable by the first unit; and

the processor of said first unit operates according to the program after the program is loaded into said first memory from said second memory.

7. The measurement system of claim 6, wherein the first unit further comprises a non-volatile memory which stores a unique identity code identifying the first unit.

8. The measurement system of claim 7, further comprising a third memory for storing the unique identity code and a description of properties of the first unit.

9. The measurement system of claim 8, further comprising a fourth memory which stores a calculated result derived from said first measurement value.

10. A measurement system comprising

a first measurement unit that obtains a first measurement value associated with a first time indication;

a second measurement unit that obtains a second measurement value associated with a second time indication; and

a processor unit that comprises a processor and receives values asynchronously from said first and second measurement units, wherein the processor synchronizes said first and second measurement values in real time using said first and second time indications.

11. The measurement system of claim 10, wherein

the first measurement unit comprises a first-unit processor that performs a calculation using the first measurement value to generate a refined measurement value associated with a third time indication that is derived from the first time indication;

and

one of the values received by the processor unit is the refined measurement value.

12. The measurement system of claim 11, wherein the refined value with the associated third time indication is used as the first measurement value with the associated first time indication when the processor performs the synchronization.

13. The measurement system of claim 10, wherein the first unit comprises

a sensor unit to obtain the first measurement value;

and

a channel unit comprising a channel unit processor for performing a calculation using the first measurement value.

14. The measurement system of claim 10, wherein the first measurement unit further comprises a clock counter for determining the time indications.

15. The measurement system of claim 10, wherein

the first measurement unit comprises a first memory and a first-unit processor;

the measurement system comprises a second memory which stores a program usable by the first unit; and

the first-unit processor operates according to the program after the program is loaded into said first memory from said second memory.

16. The measurement system of claim 15, wherein the first measurement unit further comprises a non-volatile memory which stores a unique identity code identifying the first measurement unit.

17. The measurement system of claim 16, further comprising a third memory for storing the unique identity code and a description of properties of the first measurement unit.

18. The measurement system of claim 17, further comprising a fourth memory which stores a calculated result derived from said first measurement value.

19. The measurement system of claim 10, further comprising a clock producing a clock signal wherein both first and second measurement units use said clock signal to produce said time indications.

20. A method of synchronizing measurement values, comprising the steps of

obtaining first and second streams of measurement values,

obtaining, for each measurement value, a time indication representing a time at which said measurement value was obtained, and associating said time indication with said measurement value;

processing said streams of measurement values asynchronously; and

synchronizing said measurement values from said first and second streams in real time by using said time indications.

21. The method of claim 20, wherein measurement values are unprocessed measurement values and the step of processing the streams of measurement values asynchronously comprises the steps of

producing processed measurement values by processing at least one of the streams of unprocessed measurement values;

and

determining a new time indication for each processed measurement value and associating said new time indication with said processed measurement value.

22. The method of claim 21, wherein

the new time indication of the processed measurement value is derived from the time indication of at least one of the unprocessed measurement values used to produce the processed measurement value.

23. The method of claim 22, wherein the first stream of unprocessed measurement values is obtained by sampling a measurement parameter of a test subject.

24. The method of claim 23, further comprising a step of associating with the processed measurement value a stream identity indicating the parameter represented by the processed measurement value.

25. A method of synchronizing measurement values, comprising the steps of

obtaining a first stream of measurement values,

obtaining, for each measurement value, a time indication representing a time at which said measurement value was obtained, and associating said time indication with said measurement value;

copying said first stream to produce a second stream of measurement values, and copying said time indications associated with said first stream to produce copied time indications associated with said second stream of measurement values;

processing said streams of measurement values asynchronously; and

synchronizing said measurement values in real time by using said time indications.

26. A method of measuring pulmonary compliance in a subject, comprising the steps of

obtaining a pressure value and an airflow value from the subject;

associating a first time indication with said pressure value and a second time indication with said airflow value;

performing a first calculation using said airflow value to produce a volume value;

associating with said volume value a third time indication derived from said second time indication;

performing a second calculation using said volume value to produce a breath trigger value;

associating with said breath trigger value a fourth time indication derived from said third time indication;

collecting all said values asynchronously;

synchronizing all said values in real time by using said time indications; and

performing a third calculation using all said values to produce a pulmonary compliance value.