TECHNICAL FIELD

This disclosure is in the field of tourniquets. Tourniquets are used in emergency situations or in surgical operations to control or stop blood flow to a limb. More particularly, this disclosure is in the field of nonpneumatic tourniquets.

BACKGROUND

Tourniquets are medical devices used to restrict, slow, or stop blood flow, usually to a limb but they can be used to slow or stop the flow of blood to a wound on another portion of the body. A tourniquet can be used in an emergency to save a person from life-threatening blood loss. In a situation of uncontrolled bleeding, especially from a large artery or multiple blood vessels, an injured person can bleed out in as little as sixty seconds after a traumatic injury.

One of the uses of a tourniquet is in military or paramilitary combat situations.

For example, tourniquets have become a part of basic medical training in the United States Army and tourniquets are integrated into the “Soldier as a System” (SaaS) program. The “SaaS” is everything worn, carried, or consumed by a soldier. Specific requirements for Army tourniquets have included that the device must be adequate for either upper or lower extremity application and it must include a windlass.

Preferably, the length of a tourniquet should accommodate the 99th percentile of the anthropometric size range to accommodate the increasing sizes of some patients. An effective circumferential length of about 28 inches (about 71 cm) is sufficient to accommodate most persons. More preferably, the length of a tourniquet should accommodate up to a circumference of about 37.5 inches (about 95.3 cm) to accommodate the thighs of very large persons.

Preferably, the length of a tourniquet for adults should accommodate the upper arm of a thin person. More preferably, the length of a tourniquet should accommodate down to a circumference of about 7 inches (about 18 cm). Of course, tourniquet applications for children would sometimes require even smaller sizes.

The width of a tourniquet is a factor in tourniquet design. The torque required for pressure applied by a tourniquet changes in direct relation to the width of the tourniquet. The wider the tourniquet, the less pressure is required to occlude the artery, but the wider the tourniquet more torque must be applied to the device to achieve that occluding pressure. Research shows the best median point at this time is about 1.5 inches (about 3.8 cm) for the width of a tourniquet. In addition, narrow devices have breakage and inefficacy issues, while wider ones, if used improperly, can exacerbate nerve injury. About one inch (about 2.5 cm) is a preferred minimum width and about two inches (about 5.1 cm) is a preferred maximum width. Preferably, the width of a tourniquet should be at least about 1.5 inches (about 3.8 cm).

Placement of a tourniquet can make a big difference to the effectiveness of a tourniquet. Despite having more underlying bone, the lower portions of limbs tend to be easier to occlude than the upper portions.

It is known that that limb blood occlusion pressure varies based on both limb circumference and tourniquet width. An applied pressure of 300-500 mmHg has reportedly been shown as an excellent range of safety for the tourniquets used in some tourniquet studies.

It is known that nerve palsy does not occur until 500 mmHg of pressure is applied, which is a high pressure difficult to achieve with most tourniquets. Preferably, tourniquet breakage can be adapted to occur at 500 mmHg of pressure, with significant deformation, if not outright breakage, occurring at that pressure.

Additional factors, especially for military purposes, are weight and compactness. As a tourniquet (or two) are part of the equipment carried by a soldier, weight is a factor. However, given that the weight of a tourniquet is not great, a more compact design can be more important than a small weight difference between two competing devices.

While one-handed operation (self-application) of a tourniquet is desirable in certain emergencies, especially for pilots of aircraft or special forces operations, as of 2011 the one-handed requirement was anticipated to likely be phased out from the U.S. Tactical Combat Casualty Care (“TCCC”) Guidelines. There has been a decreased percentage of self-application of tourniquets, down to close to 1% of applications. In addition, trapped-limb scenarios comprise a tiny proportion of the injured population. Nevertheless, the possibility for one-handed operation is desirable, even if not usually needed.

Clear packaging is preferred so that the user can see what is in the package. However, ultraviolet light is known to degrade a variety of materials, so packaging and component materials should be considered accordingly.

Preferably, a tourniquet for military or paramilitary application should be suitable for long-term storage in a realistic temperature extremes in the range of −60° F. (−51° C.) to +150° F. (+66° C.) and suitable for operational use in the range of −60° F. (−51° C.) to +130 F (+54° C.).

Preferably, the manufacture date and lot number should appear on the tourniquet to aid in life-cycle determination when stored for long term.

Usually only one tourniquet is issued to military or paramilitary personnel, although issuing a second tourniquet would probably be valuable and useful in some situations. For example, it has been recently reported that for the US military, “there are approximately one and a half [tourniquets] per casualty, with a max of five.”

Preferably, tourniquets should be clean, and more preferably substantially sterile for medical applications. It is desirable to minimize pathogens that are applied to the skin, especially if near a severe wound.

Tourniquets are usually considered a one-time use item, however, if a tourniquet is ineffective because of improper placement, it would be desirable if it could be removed and re-applied. A one-time use (also known as a “single-use”) tourniquet can be re-positioned for continued use on a single patient.

Preferably, simple instructions for use should be included with the tourniquet or on the packaging for the tourniquet, although often additional training will be employed for military personnel, paramilitary personnel, or first-responders.

A major problem with the use of tourniquets is difficulty staging a tourniquet for use in an emergency. It is desirable that a tourniquet be simple and quick to operate under stressful conditions. Preferably, a tourniquet should be able to be applied in less than 60 seconds. Of course, some advance training may be required to apply a tourniquet quickly.

Another major problem with some prior art tourniquets is breakages during use. A tourniquet needs to be operable and withstand breakage in actual use, otherwise it is ineffective.

With recent wars and police actions, it has become increasingly desirable to modernize and improve tourniquets.

At least as of 2019, the FDA has no specific standards for tourniquets. As of Jul. 11, 2019, a nonpneumatic tourniquet device is exempt from the premarket notification procedures in subpart E of part 807 of 21 C.F.R. Chapter 1, subject to the limitations in § 878.9. 21 C.F.R. § 878.5900(b).

Additional background information regarding tourniquets is available in the minutes of a “Tourniquet Working Group” of Mar. 23, 2010, by the U.S. Department of Defense, Defense Medical Materiel Program Office, 693 Neiman Street, 2nd Floor, Fort Detrick, Md. 21702, Memorandum dated May 2, 2011.

Numerous efforts have been made to improve on tourniquet design. Nevertheless, prior tourniquets can be difficult to apply, especially as speed of application is often required.

There has been a long-felt need for an improved nonpneumatic tourniquet, especially for use in an emergency.

SUMMARY

Assemblies, devices, apparatuses, and methods are provided for use in a tourniquet or as a tourniquet.

In various embodiments, a twisting assembly for use in a tourniquet is provided, the twisting assembly including:(A) a base part, wherein:the base part has a plurality of teeth arranged in a circle; and(B) a twisting part, wherein:the twisting part has a windlass portion, wherein a portion of a first strap of the tourniquet can be operatively connected to the twisting part such that when the windlass portion is rotated, the portion of the first strap is twisted;

wherein the twisting part is adapted to cooperatively allow movement of the twisting part away from close engagement with the teeth of the base part to allow rotation of the twisting part in one rotational direction relative to the base part; and

wherein the twisting part is adapted to cooperatively allow movement of the twisting part into close engagement with the teeth of the base part to prevent rotation of the twisting part in the opposite rotational direction relative to the base part.

In various embodiments, a twisting assembly for use in a tourniquet is provided, the twisting assembly including:(A) a base part, wherein:the base part has a plurality of teeth arranged in a circle; and(B) a twisting part, wherein:(1) the twisting part is adapted for rotating adjacent to and relative to the base part;(2) the twisting part has at least a windlass portion, wherein a portion of a first strap of the tourniquet can be operatively connected to the twisting part such that when the windlass portion is rotated, the portion of the first strap is twisted; and(3) the twisting part has a plurality of teeth arranged in a circle;

wherein the twisting part is adapted to cooperatively allow movement of the teeth of the twisting part away from close engagement with the teeth of the base part to allow rotation of the twisting part in one rotational direction relative to the base part; and

wherein the twisting part is adapted to cooperatively allow movement of the teeth of the twisting part into close engagement with the teeth of the base part to prevent rotation of the twisting part in the opposite rotational direction relative to the base part.

These and other aspects, embodiments, and advantages of the disclosed inventions will be apparent to one skilled in the art upon reading the following detailed description. While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof will be described in detail and shown by way of example. It should be understood, however, that the detailed description is not intended to limit the disclosure to the particular forms disclosed.

Detailed embodiments and examples according to the principles of the inventions are disclosed herein. However, specific portions or functional details disclosed herein are merely representative for purposes of describing example embodiments. Example embodiments can be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein. Example embodiments are capable of various modifications, equivalents, and alternatives.

