System and method for controlling pressure in a surgical tourniquet
First Claim
1. A surgical tourniquet controller, said controller comprising:
- a pressure source, said pressure source supplying a pressure medium at a sufficient pressure to pressurize a pressure cuff being used as a surgical tourniquet;
a pressure port, said pressure port allowing a pressure medium to be supplied to a pressure cuff;
a source valve, said source valve interposed between said pressure source and said pressure port;
an occlusion sensor, said occlusion sensor detecting pressure variations in the pressure medium indicative of blood flow past a pressure cuff, said occlusion sensor further generating a flow signal indicative of blood flow past a pressure cuff; and
a processor, said processor communicably connected to said occlusion sensor, said processor further communicably connected to said source valve;
wherein said processor instructs said source valve to increase the pressure in a pressure cuff when blood flow is detected past the pressure cuff.
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Accused Products
Abstract
A system and method of controlling the pressure within a pressure cuff of a surgical tourniquet so as selectively to occlude blood flow within a portion of a limb of a patient, wherein a sensor determines when flow past the tourniquet is occurring so that corrective action may be taken, such as by increasing the pressure in the tourniquet or by notifying an operator of the flow past the tourniquet. The present invention may use an acoustic sensor to detect Korotkoff sounds indicating incipient blood flow past the tourniquet. When such signals are detected, the tourniquet controller may either incrementally increase the pressure in the tourniquet, or if a threshold would be exceeded by such an increase, signal an alarm indicative of the blood flow.
62 Citations
35 Claims
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1. A surgical tourniquet controller, said controller comprising:
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a pressure source, said pressure source supplying a pressure medium at a sufficient pressure to pressurize a pressure cuff being used as a surgical tourniquet;
a pressure port, said pressure port allowing a pressure medium to be supplied to a pressure cuff;
a source valve, said source valve interposed between said pressure source and said pressure port;
an occlusion sensor, said occlusion sensor detecting pressure variations in the pressure medium indicative of blood flow past a pressure cuff, said occlusion sensor further generating a flow signal indicative of blood flow past a pressure cuff; and
a processor, said processor communicably connected to said occlusion sensor, said processor further communicably connected to said source valve;
wherein said processor instructs said source valve to increase the pressure in a pressure cuff when blood flow is detected past the pressure cuff. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A surgical tourniquet controller, said controller comprising:
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an occlusion sensor, said occlusion sensor detecting blood flow past a pressurized pressure cuff, said occlusion signal further generating a signal indicative of detected blood flow; and
a means for increasing the pressure in a pressure cuff in response to a signal indicating detected blood flow. - View Dependent Claims (18, 19, 20)
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21. A method for controlling a surgical tourniquet, said method comprising the steps of:
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inflating a pressure cuff to an initial pressure;
detecting blood flow past a pressure cuff;
incrementally increasing pressure in the pressure cuff in response to detected flow past the pressure cuff;
determining whether the increased pressure in the surgical tourniquet has occluded blood flow past the tourniquet;
when blood flow has not been occluded, continuing to incrementally increase pressure in the pressure cuff until blood flow past the tourniquet is occluded or a maximum pressure threshold is reached. - View Dependent Claims (22, 23, 24, 25)
receiving a desired inflation duration;
starting a timer when the pressure cuff is initially inflated; and
deflating the pressure cuff when the desired inflation duration has occurred.
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23. A method for controlling a surgical according to claim 21, further comprising the steps of:
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receiving a desired inflation duration;
starting a timer when the pressure cuff is initially inflated;
informing an operator when the desired inflation duration has occurred; and
deflating the pressure cuff upon command by an operator.
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24. A method for controlling a surgical according to claim 21, further comprising the steps of:
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determining a threshold pressure above which the pressure cuff should not be inflated;
ceasing incremental pressure increases when the threshold pressure is achieved; and
informing an operator that the threshold pressure has been achieved.
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25. A method for controlling a surgical according to claim 21, further comprising the steps of:
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receiving a threshold pressure above which the pressure cuff should not be inflated from an operator;
ceasing incremental pressure increases if the threshold pressure is reached; and
informing an operator that the threshold pressure has been reached.
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26. A computer readable medium tangibly embodying instructions which, when executed by a computer, cause a surgical tourniquet controller to:
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inflate a pressure cuff to an initial pressure;
receive indications from a sensor of blood flow past a pressure cuff when blood flows past the pressure cuff;
incrementally increase pressure in the pressure cuff when blood flow past a pressure cuff is detected;
determine whether the increased pressure in the pressure cuff has occluded blood flow past the pressure cuff; and
when blood flow has not been occluded, continuing to incrementally increase blood pressure until blood flow past the pressure cuff is occluded. - View Dependent Claims (27, 28, 29)
receive a desired inflation duration;
start a timer when a pressure cuff is initially inflated; and
todeflate the pressure cuff when the desired inflation duration has occurred.
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28. A computer readable medium tangibly embodying instructions according to claim 26, wherein the instructions when executed further cause a surgical tourniquet controller to:
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receive a desired inflation duration;
start a timer when a pressure cuff is initially inflated;
signal an operator when the desired inflation duration has occurred;
receive a deflate command from an operator; and
deflate the pressure cuff upon receipt of the command from an operator.
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29. A computer readable medium tangibly embodying instructions according to claim 26, wherein the instructions when executed further cause a surgical tourniquet controller to:
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determine a threshold pressure above which the pressure cuff should not be inflated;
cease incremental pressure increases when the threshold pressure is achieved; and
inform an operator that the threshold pressure has been achieved.
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30. A surgical tourniquet system, including a pressure cuff that may be closed around a patient'"'"'s limb so as to exert pressure on blood vessels within a portion of the limb, comprising:
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an inflatable cuff containing a first quantity of gas having a first internal pressure;
an inflatable bladder containing a second quantity of gas having a second internal pressure;
a first conduit between said inflatable cuff and said inflatable bladder;
a first valve within said first conduit;
a controller connected to said first valve; and
a flow sensor connected to said first conduit, said flow sensor between said first valve and said inflatable cuff, wherein, when the pressure in said inflatable cuff is greater than that in said inflatable bladder, said controller decreases the pressure in said inflatable cuff by opening said first valve;
wherein, when the pressure in said inflatable cuff is less than that in said inflatable bladder, said controller increases the pressure in said inflatable cuff by opening said first valve; and
wherein when the flow sensor detects flow past the inflatable cuff, the second internal pressure in the inflatable bladder is incrementally increased. - View Dependent Claims (31)
a pump connected to said controller;
a second conduit between said pump and said inflatable bladder;
a second valve within said second conduit and connected to said controller, wherein said controller increases the pressure in said inflatable bladder by opening said second valve and pumping gas from outside the surgical tourniquet system into said inflatable bladder; and
wherein said controller decreases the pressure in said inflatable bladder by opening said second valve, thereby equalizing the pressure in said inflatable bladder with that of the atmosphere.
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32. A method of controlling the pressure within a surgical tourniquet system so as selectively to occlude blood flow within a portion of a limb of a patient, comprising the steps of:
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(a) decreasing the pressure within an inflatable cuff surrounding a portion of a limb of a patient by automatically opening a first valve connected to a controller and located within a first conduit between an inflatable bladder and the inflatable cuff, when the pressure in the inflatable cuff is greater than that in the inflatable bladder;
(b) increasing the pressure within an inflatable cuff surrounding a portion of a limb of a patient by automatically opening a first valve connected to a controller and located within a first conduit between an inflatable bladder and the inflatable cuff, when the pressure in the inflatable cuff is less than that in the inflatable bladder; and
(c) when flow past an inflatable cuff is detected, incrementally increasing the pressure within an inflatable bladder.
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33. A surgical tourniquet system, comprising:
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an inflatable cuff;
a controller connected to said inflatable cuff;
a flow sensor; and
a display connected to said controller, wherein a user controls the surgical tourniquet system by means of a graphical user interface displayed on said display. - View Dependent Claims (34, 35)
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Specification