Integrated Tourniquet System

• US 20100211096A1
• Filed: 02/19/2009
• Published: 08/19/2010
• Est. Priority Date: 02/19/2009
• Status: Active Grant

• Current Assignee: Western Clinical Engineering Ltd.
• Original Assignee: Western Clinical Engineering Ltd.
• Inventors: McEwen, James A., Jameson, Michael, Gebert, Michael A., Cheung, William K.W.
• Granted Patent: US 9,113,895 B2
• Time in Patent Office: Days
• US Class Current: 606/203
• CPC Class Codes: A61B 17/132 Tourniquets sphygmomanometer A61B5/022
• CPC Class Codes: A61B 17/1322 comprising a flexible encircling member A61B17/135 takes precedence
• CPC Class Codes: A61B 17/135 inflatable for measuring blood pressure A61B5/022; inflatable pressure pads A61F5/34
• CPC Class Codes: A61B 17/1355 Automated control means therefor
• CPC Class Codes: A61B 2017/00119 alarm; indicating an abnormal situation
• CPC Class Codes: A61B 2017/00132 Setting operation time of a device A61B2017/00123 takes precedence
• CPC Class Codes: A61B 2017/00221 with wireless transmission of data, e.g. by infrared radiation or radiowaves
• CPC Class Codes: A61B 2090/0809 Indication of cracks or breakages
• 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 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02208 using the Korotkoff method
• CPC Class Codes: A61B 5/02225 using the oscillometric method
• CPC Class Codes: A61B 5/02241 of small dimensions, e.g. adapted to fingers
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/0235 Valves specially adapted therefor

Abstract

An integrated tourniquet system enables the user to establish with suitable warnings, and with timely user confirmation, individualized maximum pressure levels in the cuff that may be above normal maximum pressure levels. Also provided is a rapid and accurate method of testing for leakage in the cuff and connectors. The system is adapted for communication to remote devices for receiving and providing information relating to the pressure levels, tests, etc.

Claims

1. An integrated tourniquet system, comprising:

an inflatable tourniquet cuff releasably connectable through a connector and tubing to a tourniquet pressure regulator, thereby establishing a gas passageway between the cuff and the regulator;

pressure sensing means for producing an indication of a level of pressure in the cuff and passageway;

a tourniquet pressure regulator that operates to regulate the level of pressure in the cuff and passageway near a reference pressure level over a surgical time period suitably long for the performance of a surgical procedure;

test means responsive to a request for initiation of a leakage test for disabling the operation of the pressure regulator for a test period sufficient to perform a test to estimate a magnitude of leakage from the cuff and passageway, and for enabling the operation of the pressure regulator at the end of the test period.

2. The apparatus as defined in claim 1 wherein the test means performs the leakage test by inflating the cuff and passageway to a first level of pressure at a first test time and estimates a magnitude of leakage of gas from the cuff and passageway as a predetermined function of the first level of pressure and a second level of pressure sensed in the cuff and passageway at a second test time within the test period.

3. The apparatus as defined in claim 2 wherein the test means is responsive to the indication of the level of pressure in the cuff and passageway to inhibit the performance of the leakage test if the level of pressure is substantially different from zero at the time of the request.

4. The apparatus as defined in claim 2 wherein the test means is responsive to the reference pressure level and wherein the test means inhibits the performance of the leakage test if the reference pressure level is substantially different from zero at the time of the request.

5. The apparatus as defined in claim 2 wherein the predetermined function evaluates the magnitude of the difference between the first level and the second level.

6. The apparatus as defined in claim 2 wherein the interval between the first test time and the second test time is predetermined.

7. The apparatus as defined in claim 2 wherein the magnitude of the difference between the first test pressure level and the second test pressure level is predetermined.

8. The apparatus as defined in claim 1 wherein the operation of the pressure regulator is controlled by at least one electrical signal and wherein the test means disables the operation of the pressure regulator by inhibiting the electrical signal.

9. The apparatus as defined in claim 1 wherein the test means disables the operation of the pressure regulator by closing the pneumatic passageway near the pressure regulator.

10. The apparatus as defined in claim 1 wherein the test means further stores a value indicative of the estimate of the magnitude of leakage, and wherein the apparatus further includes communication means for communicating the stored value to a location remote from the apparatus and for presentation of the stored value in a form perceptible by a user.

11. The apparatus as defined in claim 1 and including communication means for communicating the estimate of the magnitude of leakage to remote apparatus.

12. An integrated tourniquet system, comprising:

an inflatable tourniquet cuff releasably connectable through a connector and tubing to a tourniquet pressure regulator, thereby establishing a gas passageway between the cuff and the regulator;

a tourniquet pressure regulator operable for regulating the level of pressure in the cuff near a reference pressure level over a surgical time period suitably long for the performance of a surgical procedure;

test means operable for disabling the operation of the pressure regulator for a test period and for enabling the operation of the pressure regulator at the end of the test period, and further operable for estimating a magnitude of leakage of gas from the cuff and passageway.

13. The apparatus as defined in claim 12 further comprising pressure estimation means for producing an estimate of a level of pressure in the cuff and wherein the test means is further responsive to the estimated level of pressure and wherein the test means is further operable for inhibiting the test if the estimated level of pressure is greater than zero at a time of the request.

14. An integrated tourniquet system, comprising:

an inflatable tourniquet cuff releasably connectable through a connector and tubing to a tourniquet pressure regulator, thereby establishing a gas passageway between the cuff and the regulator;

pressure sensing means for producing an indication of a level of pressure in the cuff;

a tourniquet pressure regulator operable for regulating the level near a reference pressure level;

reference pressure setting means adapted for enabling a desired tourniquet cuff pressure value to be received and including;

normal pressure setting means adapted for setting the reference pressure level to the value if the value does not exceed a predetermined safe limit; and

extended pressure setting means operable in instances where the value exceeds the safe limit for producing a hazard indication perceptible to a user and for setting the reference pressure level to the value only if the user produces a confirmation signal through a user interface.

15. The apparatus as defined in claim 14 wherein the extended pressure setting means is further operable for setting the reference pressure level to the value only if the user produces the confirmation signal within a predetermined period of time after the hazard indication is produced.

16. The apparatus as defined in claim 14 wherein the user interface of the extended pressure setting means is adapted for enabling the desired tourniquet cuff pressure value to be established by the user and for producing the hazard indication perceptible to the user.

17. The apparatus as defined in claim 14 wherein the user interface of the extended pressure setting means is adapted for producing an extended pressure indication perceptible to a user during a period of time when the reference pressure level exceeds the safe limit.

18. The apparatus as defined in claim 14 and including communication means adapted for receiving data indicative of the desired tourniquet cuff pressure value from remote apparatus.

19. The apparatus as defined in claim 14 and including communication means for communicating data indicative of the operation of the extended pressure setting means to a location remote from the apparatus.

20. An integrated tourniquet system having at least two operational states identifying whether the system is operable in a first state for maintaining a level of pressure in a tourniquet cuff near a reference pressure level or operable in a second operational state, and including connectivity means adapted for receiving a request from remote apparatus for a value that is stored in the system, for transmitting the value to the remote apparatus in response to the request during the first operational state, and for inhibiting transmission of the value to the remote apparatus during the second operational state.

21. The apparatus as defined in claim 20 wherein the value is the level of pressure in the tourniquet cuff.

22. The apparatus as defined in claim 21 wherein the system is operable in the second operational state for testing the magnitude of leakage from the tourniquet cuff.

23. The apparatus as defined in claim 20 wherein the connectivity means is further adapted to facilitate wireless communication with the remote apparatus.

24. An integrated tourniquet system having at least two operational states identifying whether the system is operable in a first operational state for maintaining a level of pressure in a tourniquet cuff near a reference pressure level or operable in a second operational state, and including connectivity means adapted for receiving a request from remote apparatus to change a level of a predetermined parameter, for changing the level in the first operational state, and for inhibiting a change of the level in the second operational state.

25. The apparatus as defined in claim 24 wherein the predetermined parameter is the level of pressure to be maintained in the tourniquet cuff.

26. The apparatus as defined in claim 25 wherein the second operational state occurs when the level of the predetermined parameter is greater than a safe limit.

27. A method of setting a tourniquet cuff pressure to a level greater than a normal safe limit, comprising the steps of:

connecting an inflatable tourniquet cuff to a tourniquet pressure regulator, thereby establishing a gas passageway between the cuff and the regulator;

setting a reference pressure level to a value indicative of a desired tourniquet cuff pressure, provided the value does not exceed a predetermined safe limit;

indicating to a user in instances where the value exceeds the safe limit and setting the reference pressure level to the value only if the user provides a manual confirmation after the indication to the user;

sensing a level of pressure in the cuff; and

regulating the level of pressure in the cuff near the reference pressure level.

28. The method of claim 27 wherein the indicating step includes limiting the time during which the user may provide the manual confirmation.

29. A method of testing pneumatic leakage from a tourniquet cuff and gas passageway connecting the cuff to a pressure regulator, comprising the steps of:

estimating a level of pressure in a tourniquet cuff and connected gas passageway;

inhibiting performance of a leakage test if the estimated level of pressure is substantially different from zero;

performing the leakage test if the estimated level of pressure is near zero by disabling regulation of pressure in the cuff for a leakage test period and,

pressurizing the cuff and gas passageway during the leakage test period to a first test level of pressure at a first time, measuring a second test level of pressure at a second time occurring after the first time and

estimating a magnitude of leakage as a function of the magnitude of the difference between the first test level and the second test level.

30. The method of claim 29 and including the step of enabling a user to initiate the performance of the leakage test at a time when the estimated level of pressure is near zero.

31. The method of claim 29, including the step of deflating the cuff after the second time and further including the step of thereafter enabling the regulation of the pressure in the cuff.

32. The method of claim 29 and including the step of producing a human-perceptible indication if the magnitude of leakage is greater than a predetermined magnitude.

33. The method of claim 29 wherein a plurality of additional test levels of pressure are measured at a plurality of additional times occurring between the first time and the second time while the operation of the pressure regulating means is disabled, and wherein the estimate of the magnitude of leakage is a predetermined function of the first and second test levels of pressure at the first and second times respectively and of the plurality of additional test levels at the plurality of additional times.

34. The method of claim 29 wherein the step of enabling the user to initiate the performance of the leakage test is facilitated by means of a user interface, and wherein the step of disabling the pressure regulation further includes providing a user-perceptible indication while the operation is disabled.

35. A method for testing for leakage from a tourniquet cuff and gas passageway connecting the tourniquet cuff to a pressure regulator, comprising the steps of:

estimating a level of pressure in the tourniquet cuff and connected gas passageway;

if the estimated level of pressure is substantially different from zero, preventing initiation of a leakage test;

if the estimated level of pressure is near zero, enabling initiation of the leakage test;

if the leakage test is initiated, increasing pressure in the cuff and passageway to a first level of pressure near a first time, measuring a second level of pressure at a second time after the first time wherein during the period between the first time and the second time a pressure regulator normally operable for maintaining a level of pressure in the tourniquet cuff and connected gas passageway near a reference pressure level is disabled, and

determining a magnitude of difference between the first and second levels of pressure and producing an indication of leakage as a predetermined function of the magnitude.

36. The method of claim 35 and including the step of deflating the cuff after the second time.

37. The method of claim 35 and including the step of enabling the operation of the pressure regulating means after the second time.

38. The method of claim 35 wherein the first level of pressure is predetermined and wherein the second time is predetermined.

39. A method of transmitting a value from an integrated tourniquet system, comprising the steps of:

identifying a first operational state in which a level of pressure in a tourniquet cuff is maintained near a reference pressure level;

receiving a request from remote apparatus for a value that is stored in the system;

in the first operational state, transmitting the value to the remote apparatus in response to the request; and

in the second operational state, inhibiting transmission of the value to the remote apparatus.

40. A method of receiving a value by an integrated tourniquet system, comprising the steps of:

identifying a first operational state in which a level of pressure in a tourniquet cuff is maintained near a reference pressure level;

identifying a second operational state;

receiving a request from remote apparatus to change a level of a predetermined parameter;

in the first operational state, changing the level; and

in the second operational state, inhibiting a change of the level.