Patent Application
20220233339
This disclosure relates to medical devices.
The problem with loads on casts is that the flesh of the foot inside the cast experiences the same loads. The heel is of particular concern because it develops ulcers with minimal contact of the cast with any surface. Applicant has found no notable solutions to this problem in the prior art.
This inventor arrived at this design as an orthopedist, in a Technician's capacity, over the course of 30 plus years of experience. It is a necessary improvement to the art of cast making.
This disclosure describes an apparatus, and similar nonlimiting exemplary embodiments.
What is needed and not found in the prior art are devices that prevent heel sores in casts. This is done through braces that both redirect common forces and create awkward obstructions that discourage certain improper placements of the cast.
This disclosure provides a preferred brace and alternate embodiments. This specification also teaches the use of various embodiments. The methods can be used to install similar apparati that accomplish the same objectives. It is imperative to clarify that the braced walking cast can bear usual loading on the cast, but routine loading on the brace is generally limited to when a patient is in a sitting or lying down.
In this specification there are two loads discussed. The heel of the patient's foot should experience zero loading. The brace is designed to transfer any potential loading away from the heel of the foot. Thus, the brace will experience a second load and is rated accordingly. In sum, there is a heel load, and there is a brace load. This specification will always refer to the brace loading, and not the foot or heel loading unless specifically stated otherwise.
The intent of the brace herein disclosed is to redistribute the brace load away from the heel. In this specification, the preferred heel loading is zero pounds. However, to accommodate loads up to approximately 5 pounds, this bracing is helpful. BRACE LOADING OF 5 POUNDS IS IN NO WAY IMPLIED OR RECOMMENDED BY THIS METHOD, IT IS BEST THAT NO BRACE LOADING IS EVER PRESENTED. In this specification, 5 pounds is used as a symbolic, but approximately accurate load and does not imply a specific load limit. In practice, a practitioner would select from a variety of braces according to the patient's lifestyle and medical need.
In this specification, an embodiment of the brace has a maximum load rating of 25 pounds or even more for the expected durability of the brace during an expected load. The brace capability should exceed the safe loading for the patient. In such a nonlimiting embodiment, a practitioner should determine and warn the patient of the brace loading limits that are safe for the patient.
The solution herein disclosed redirects common axial forces on the cast from the heel area to points of contact above and forward of the heel, distributing point loads over the entire rear section of the cast. The primary embodiment includes one brace to protect the back of the heel from contacts. In an embodiment, the brace is secured to a finished leg cast. Securing is done by means that do not compromise the integrity of the finished cast by using nonlimiting examples like fiberglass rolls, plaster or other methods familiar to those in the field of orthopedics.
In a preferred embodiment, installing a geometrically rectangular brace to the cast behind the foot creates a normal and balanced horizontal position of the cast on a surface, with the toes straight up. A reason for the rectangular shape aligning the foot in this orientation is to prevent pivoting the cast along the leg center axis. This pivoting, in turn creates unwanted and unusual loading, which causes possible injury at the knee. In the case of a broken bone, such unwanted loading could affect the healing of the bone and alignment.
Further, a rectangular brace with 2 right angles that form corners connected by a flat section can be used to provide a stable, preferred loading effect. This encourages a patient to utilize normal, balanced preferred positioning. Further, geometry can be shaped according to a practitioner's preference to prevent unwanted loading. For example, a preferred load and shape could protect an incision that might be aggravated by certain loading. Such geometry includes but is not limited to shapes that have flat sections according to another preferred loading and pointed sections according to nonpreferred loading, such loads being applied by a patient to the cast in the common use and in their particular lifestyle.
In this specification the word brace is considered synonymous with other terms used herein, including “bracket” and “spacer”. In this specification the concept of a cast is used as an exemplary application. One of ordinary skill in the art would see that this method would apply to bracing other applications such as splints and nonweightbearing casts.
Common loading refers to loads that many cast wearers would apply to the heel in normal activities for an injured person. As a nonlimiting example, this includes a forward force directed from the heel area toward the toes during the frequent placement of the cast horizontally aligned and resting on a horizontal surface.
In the preferred embodiment, one brace is used on a single weightbearing leg cast. In a nonlimiting embodiment, the brace is attached at 4 points including two points on the left side and two on the right. In another nonlimiting embodiment a single attachment point is used on either side. In a third embodiment, integral tabs or ears are incorporated on the brace to further stabilize the brace when secured.
In the preferred embodiment, the multiple attachment points per side and tabs make it is possible to redirect common forces to any “best” part of the cast using eccentric torque loading instead of single mounting attachments. That is to say, with the single attachment per side, all forces are directed to each point of attachment. A patient-protecting part of the body to which a load can be directed is to the back of the ankle—along the Achilles.
In another nonlimiting embodiment, to redirect the load, the rear brace attaches with at least two points on either side of the ankle for at least 4 points. Thereby, with the brace the common forces impact the brace instead of the back of the cast, and usually create a torque instead of a direct impact. To be clear, a single, common force applied to the cast in a direction toward the heel, would in turn be applied “off center” to multiple eccentrically located attachments, to create a torque around the braced cast assembly.
In an embodiment having two attachment points on each side, of the ankle area the first attachment point is lower than the other—one toward the sole of the foot and the other higher in the ankle area—perhaps ½″ apart. The attachment points are also slightly (e.g. V) offset forward and rearward. With this 4-point mounting, any common load directed toward the back of the heel would be received by the multiple attachment points unevenly—eccentrically. This would cause a torque and apply the force at the back of the leg or on the sole of the foot. With an alternative positioning of the 4 mounting points a common force and resulting torque could be applied wherever is best.
An alternative nonlimiting embodiment will also prevent contact at the heel. The idea is to add an audible “click” at the brace to notify the wearer that a maximum load has been experienced by the cast. In an embodiment the clicking device should reset with no additional human intervention—spring loaded perhaps—so that it is repetitive, notifying the wearer of his/her overloading. The intent of the design is to be disruptive and attention-getting for the wearer, and to create notice and an incentive to avoid overloading the cast.
Another alternative embodiment helps children who have casts. Children are notorious for overloading the cast at the heel. It is important to reiterate that: LOADING OVER 5 POUNDS IS IN NO WAY IMPLIED ENCOURAGED OR RECOMMENDED BY THIS METHOD. The suggestion is to install decorative but functional attachments. In a nonlimiting embodiment, the design has reshaped braces that are decorative and aesthetically appealing, but also functional designs. As a nonlimiting example, floral shapes of suitable size, shape and material are be attached as part of the method. As another example, the braces themselves may be formed from the supplier with pair of ears shape and a tail shape. In another example, the reshaping elements are formed and attached to the braces at the factory, or the same elements can be attached to the braces by the practitioner.
Another embodiment continues to use electronics that would allow both notice that an overload has occurred and there is an aesthetic advantage for younger wearers. Again: LOADING OVER 5 POUNDS IS IN NO WAY IMPLIED, ENCOURAGED OR RECOMMENDED BY THIS METHOD.
In a nonlimiting embodiment, Electronics include switches mounted on the braces to activate upon a 5 # overload, with red LED indicators that flash for 5 seconds when an overload condition is momentarily present. Electronics can include a sonolert—an audible alarm to indicate an overload condition. The alarm can be a click, for subtlety. The alarm can be a garish siren.
In an embodiment, Other electronics include a molded pressure pad with at least one pressure sensor that respond to 5 # loading. Schmersal sms4-500-500 is an exemplary pressure mat with about 244 sensors. This would be overkill but offers the concept of a low-profile mat with multiple input sensors. In this application, only 4 to 6 sensors are needed in a minimal arrangement.
In an embodiment, in place of the braces, a single, rigid, molded cap is installed using the methods herein disclosed and used as a shield around the entire heel area. Again: LOADING OVER 5 POUNDS IS IN NO WAY IMPLIED, ENCOURAGED OR RECOMMENDED BY THIS METHOD. The cap would secure to the cast similar to the braces—at two opposite sides of the heel. The cap, however, could be closer to the cast than ¼″ previously outlined. In an embodiment, the caps have electronic switches and lighted outputs that mount and operate similar to those previously discussed.
Also, a seal around the edges of the cap will seal the cap to the surface of the cast. This seal can also be made of a rigid material sufficient to create a ring of contact between the cap and the cast where the redirected forces would be applied along a sizeable contact area.
A familiar and similar concept is used to protect a broken nose from contact (often used for basketball). In this exemplary concept, the mask redirects any forces away from the nose area and to other parts of the face. One of ordinary skill in the art would be familiar with materials appropriate to the application, including but not limited to plastics, carbon fiber and metal.
In an embodiment, a direct force testing system is employed and installed with each brace. This embodiment would be useful as a test mechanism or in applications that require the accurate measurement of the forces applied to a cast and in turn applied to the leg and foot of the patient. Force sensing pads (a nonlimiting example is a pair of pads electronically connected by a normally open switch) are used at force transfer contact points and molded onto the cast by applying an additional pad at the places where the load is more optimally applied. The concept of a broad, soft pad at the heel was rejected because it could result in undesired contact and a resulting ulcer. However, the top of the foot, the bottom sole of the foot and the back of the ankle are mentioned herein as good places to direct/redirect forces. At these locations, an applied force can be measured to protect the patient. An installer places the force pad in contact with the cast (or even inside the cast to the cast liner or to the foot/leg) at the best points for measuring redirected contact forces—and then secures to the completed cast as needed. Force pad readings are communicated using direct wiring or externally mounted wireless devices.
Certain nonlimiting embodiments are outlined herein, and one of ordinary skill in the art would be aware of modifications or alternatives that would be similar. One of ordinary skill in the art would also be aware of tools and hardware to aid in the installation process, and would use such items to brace, stabilize, locate, prepare, install, secure and similarly apply the methods herein disclosed.
Drafting note: 520 demonstrates the securing straps and Velcro that are used to secure a walking shoe to a weightbearing cast. These securing straps are demonstrative, nonlimiting and are not shown in other views for clarity.
Note: though a plaster or fiberglass cast is demonstrated in the figures, other cast-like devices are used to therapeutically secure parts of the body. The brace concept will work with other cast-like devices like a post-operative cast shoe and a 3d printed cast.
LED lamp strips with a dispersion lens. 760 demonstrates a sonolert sound generator. The sensors, lamps and sonolerts are wired together so that the sensors activate the lamps and sonolerts when a preset load limit is experienced by the brace and sensors.
