Systems and methods for tourniquet operation and control

1 . A tourniquet monitoring system comprising:

a pressure sensor, wherein the pressure sensor includes a capacitive pressure sensor;

a housing configured to removably engage a tourniquet to position the pressure sensor on a limb of a patient to monitor at least one of deployment or operation of the tourniquet, wherein the pressure sensor is supported by the housing and is configured to contact the limb;

a processor configured to receive feedback from the pressure sensor, compare the feedback to at least one of deployment or operation parameters for the tourniquet, determine a first threshold pressure corresponding to a pressure value necessary for occlusion to sufficiently stop or hinder bleeding, determine a second threshold pressure corresponding to a pressure value for complete occlusion of blood flow through the limb, monitor an elapsed time from when the tourniquet reaches a pressure between the first threshold pressure and the second threshold pressure, and generate a user report; and

a user communication module configured to communicate the user report.

2 . The system of claim 1 , wherein the capacitive pressure sensor is configured to be arranged between the tourniquet and a patient wearing the tourniquet when the housing is engaged with the tourniquet.

3 . The system of claim 2 , wherein the capacitive pressure sensor is configured to be compressed as the tourniquet is tightened against the patient.

4 . The system of claim 2 , wherein the housing includes a mounting passage configured to receive the tourniquet to secure the housing to the tourniquet and arrange the capacitive pressure sensor between the tourniquet and the patient.

5 . The system of claim 2 , wherein the processor is configured to monitor a pressure applied by the tourniquet on the patient based on the feedback from the capacitive pressure sensor.

6 . The system of claim 5 , wherein the user report includes real-time pressure reports indicating the pressure applied by the tourniquet on the patient.

7 . The system of claim 5 , wherein the user report includes a pressure alert when the pressure applied by the tourniquet on the limb is below the first threshold pressure or above the second threshold pressure.

8 . The system of claim 5 , wherein the user report includes one of a visual, graphic, audible, or tactile indication communicating when the pressure applied by the tourniquet on the limb is (i) below the first threshold pressure or above the second threshold pressure or (ii) between the first threshold pressure and the second threshold pressure.

9 . The system of claim 1 , further comprising an oxygenation sensor configured to monitor oxygenation of the tissue proximate to the tourniquet when the tourniquet is engaged with the limb.

10 . The system of claim 9 , wherein the processor is configured to analyze the feedback from the oxygenation sensor to determine the oxygenation of the tissue proximate to the tourniquet and generate an oxygenation alert communicated to a user via the user communication module if the oxygenation of the tissue proximate to the tourniquet is outside a desired range.

11 . The system of claim 9 , wherein the oxygenation sensor includes at least one of a spectroscopic sensor or a lifetime sensor configured to monitor tissue proximate to the tourniquet when the tourniquet is engaged with a patient.

12 . The system of claim 11 , wherein the oxygenation sensor includes a needle configured to extend the at least one of the spectroscopic sensor or the lifetime sensor into the tissue when the tourniquet is deployed on the patient.

13 . The system of claim 12 , wherein the at least one of the spectroscopic sensor or the lifetime sensor includes at least one of a plurality of spectroscopic sensors or a plurality of lifetime sensors, and further comprising a plurality of needles configured to extend the plurality of spectroscopic sensors or the plurality of lifetime sensors into the tissue when the tourniquet is deployed on the patient.

14 . The system of claim 13 , wherein each of the plurality of needles is a microneedle and the plurality of needles forms an array of microneedles.

15 . The system of claim 13 , wherein the plurality of needles is arranged within a needle housing and extends into the tissue of the patient as the tourniquet is tightened about the patient.

16 . The system of claim 15 , wherein the needle housing is formed of a foam configured to compress as the tourniquet is tightened about the patient.

17 . The system of claim 1 , further comprising a temperature sensor configured to monitor a temperature of tissue proximate to the tourniquet when a patient is wearing the tourniquet.

18 . The system of claim 1 , wherein the user communication module includes at least one of a display, a speaker, and a tactile module.

19 . The system of claim 1 , further comprising at least one of a communications port or a wireless communications system configured to communicate to a remote device.

20 . The system of claim 1 , wherein the processor is configured to analyze the feedback from the pressure sensor to determine a change in a rate of change in the feedback from the pressure sensor.

21 . The system of claim 1 , wherein the housing includes a coupling system configured to one of clip on or slide onto a sleeve of the tourniquet.

22 . The system of claim 21 , wherein the coupling system is a u-shaped structure defining a mounting passage through which the sleeve of the tourniquet is fed to removably engage the tourniquet with the housing.

23 . The system of claim 1 , wherein the pressure sensor includes an accelerometer configured to monitor movement of the tourniquet when a patient is wearing the tourniquet.

24 . The tourniquet of claim 1 , wherein monitoring the elapsed time includes a countdown from one or more threshold numbers.

25 . The tourniquet of claim 24 , wherein the one or more threshold numbers includes a maximum tourniquet time or an extended tourniquet time corresponding to the time the tourniquet is positioned on the limb.

26 . The tourniquet of claim 25 , wherein the processor is further configured to provide one or more time alerts corresponding to the countdown reaching the one or more threshold numbers.

27 . A method for monitoring an occlusive effect of a tourniquet on a human limb, the method comprising:

providing a tourniquet;

retrofitting a system onto the tourniquet by removably attaching a housing of the system to the tourniquet, the system including:

the housing,

a capacitive pressure sensor supported by the housing,

a processor, and

a user communication module;

tightening the tourniquet around the human limb so that the capacitive pressure sensor contacts the human limb and is interposed between the tourniquet and the human limb;

sensing a compressive force between the tourniquet and the human limb via the capacitive pressure sensor;

determining a first threshold pressure of the tourniquet corresponding to a pressure value necessary for occlusion to sufficiently stop or hinder bleeding, determining a second threshold pressure of the tourniquet corresponding to a pressure value for complete occlusion of blood flow through the human limb;

monitoring an elapsed time from when the tourniquet reaches a pressure between the first threshold pressure and the second threshold pressure; and

communicating a user report via the user communication module, the user report including at least one of the compressive force and the elapsed time.

28 . The method of claim 27 , wherein the system includes an oxygenation sensor; and further comprising tightening the tourniquet around the human limb so that the oxygenation sensor contacts tissue of the human limb; and sensing an oxygenation level of the tissue, wherein the user report further includes the oxygenation level.

29 . The method of claim 27 , further comprising analyzing the compressive force to determine when the tourniquet is sufficiently tightened, wherein the user report includes a pressure alert that the tourniquet is below the first threshold pressure or above the second threshold pressure.

30 . The method of claim 27 , wherein communicating the user report includes at least one of displaying one of text or graphics on a screen, illuminating one or more LEDs, providing an audible indication, and providing a tactile response.

31 . The method of claim 27 , further comprising transmitting the user report to a remote device, remote from the system.

32 . A tourniquet system for use on a human limb, comprising:

a field tourniquet;

a housing configured to removably engage the tourniquet;

a capacitive pressure sensor positioned relative to the housing and the tourniquet so the pressure sensor is configured to contact the human limb and is interposed between the tourniquet and the human limb for sensing compressive force therebetween when the housing is engaged with the tourniquet;

an oxygenation sensor positioned relative to the housing and the tourniquet so the oxygenation sensor is interposed between the tourniquet and the human limb for sensing oxygen levels of the human limb when housing is engaged with the tourniquet;

a processor configured to receive feedback from the capacitive pressure sensor and the oxygenation sensor, compare the feedback to at least one of deployment or operation parameters for the tourniquet, determine a first threshold of the tourniquet corresponding to a pressure value necessary for occlusion to sufficiently stop or hinder bleeding, determine a second threshold pressure of the tourniquet corresponding to a pressure value for complete occlusion of blood flow through the human limb, monitor an elapsed time from when the tourniquet reaches a pressure between the first threshold pressure and the second threshold pressure, and generate a user report; and

a user communication module configured to communicate the user report.