System and method for controlling pressure in a surgical tourniquet

A method for controlling a surgical tourniquet, said method comprising the steps of:

• 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.

A computer readable medium tangibly embodying instructions which, when executed by a computer, cause a surgical tourniquet controller to:

• 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.

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:

• 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.

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:

• (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.

A surgical tourniquet system, comprising:

• 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.