WO2011070438A2

WO2011070438A2 - A medical device for limb immobilization

Info

Publication number: WO2011070438A2
Application number: PCT/IB2010/003195
Authority: WO
Inventors: Rahul Ribeiro; Asokan Thondiyath; Darshan Nayak; Pulin M. Raje; Gabriel Howles Banerji; Vijaykumar Rajasekhar; Wenson R. Chern; Matthew Durack
Original assignee: Stanford-India Biodesign
Priority date: 2009-12-11
Filing date: 2010-12-10
Publication date: 2011-06-16
Also published as: WO2011070438A3; WO2011070438A4

Abstract

A device which immobilizes and supports the injured parts of the body, especially the extremities. It comprises a substantially planar shaped body with a broad head portion and a tapering tail portion, the body provided with a plurality of slots on either of its sides; a plurality of spaced apart fastening elements extending transversely of the body portion and adapted to anchor on the slots present on the planar body; wherein at least in the slots are placed in a manner such that the fastening elements provide adequate support to the limb. The invention also encompasses a kit comprising the device along with accessories like rods, padding devices, extra fastening elements

Description

A MEDICAL DEVICE FOR LIMB IMMOBILIZATION

FIELD OF INVENTION:

The present invention relates to a device which immobilizes and supports the injured parts of the body, especially the extremities. The device is particularly more useful at pre-hospital/ pre-treatment stage.

BACKGROUND OF THE INVENTION:

In any trauma case, the most common extremity injuries are fractures, dislocation, sprain, strain or contusions resulting from either blunt, penetrating or crush type of injuries. The pre- hospital care infrastructure is still not well developed and even a well established ambulance service does not have a organized emergency medical services (EMS) system, hence the quality of pre-hospital care is very in-consistent. The risk of aggravating the injury is very high during transportation to the nearest hospital, transferring patient from an ambulance to gurney, gurney to bed etc. It is a prerequisite that in an extremity injury, the limb has to be immobilized as soon as possible. Failure of immobilization may lead to further complications such as Hemorrhage and shock, additional Pain, Fracture healing malunion, Nerve damage etc which may result in paraesthsis/ paraplegia etc.

Often in several circumstances, there is no effective practical method of safely immobilizing the fracture to enable the patient to be transported from the site at which the fracture occurred, to hospital. Patients do not use any device for immobilization immediately after the incidence and most of the time he/she runs to hospital by easiest available means of transport, without any precautionary measures to prevent further damage. Sometimes, people tend to use wooden sticks, tapes and ropes or any crude method like Normal Plaster which is easily available to provide initial immobilization. This method is neither very efficient nor effective. There are immobilization devices which are available in the market like-splint, but are not very useful in cases of obese patients or pediatrics. The available devices are difficult in the quick assembly of their components and are bulky making them cumbersome for practical use. Another immobilization device available in the market like SAM splint (made of AJuminum) is not well equipped for prolonged use (more than few hours). On prolonged usage, it may lead to skin irritation and if not cut properly, the sharp edges may hurt the patient or the person applying it. Moreover, the cost these devices are very high.

In case of inflatable immobilization devices, these need to be inflated with a pump which makes these devices cumbersome to store and carry.

The products available in the market are either bulky or expensive or are difficult to use. Also, these products are generally radio-opaque, meaning that they interfere with X-rays making it difficult for the doctor to diagnose fractures or other types of injuries. Hence, such products are typically removed from the patient before the patient is subjected to x-ray, increasing the distress of the patient and increasing chances of dislocation or aggravation of the fracture/injury.

Furthermore in many countries, the cost factor of the device is very important. The hospitals, in an attempt to save on unnecessary expenditure, tend to reuse costly devices, which drastically increases the chances of secondary infections. There are certain disposable immobilization devices that are reported in the literature. However, these immobilization devices do not adequately support the fracture/ limb and hence are not very effective. Further, the devices of the prior art, are not designed so as to provide immobilization of joints above and below the injured area. Most importantly, the devices in the market do not adequately support the extremities at specific areas with high muscle bulk such as inguinal area, the shoulder joint etc where the fragmented pieces of a fracture are pulled/displaced due of uninhibited muscle action. In order to prevent the situation of major complications in the cases like fracture, it is necessary to develop a device which overcomes the above mentioned disadvantages and is able to immobilize and support the extremity whilst allowing easy access to open injuries.

OBJECTS OF THE INVENTION:

The principal object of the present invention is to provide a temporary and disposable device which immobilizes and supports an injured extremity of the body.

BRIEF DESCRIPTION OF THE FIGURES:

FIG. 1 depicts an embodiment of the immobilization device constructed according to the present invention.

FIG 2 demonstrates various embodiments of the immobilisation device of the present invention Fig (2.1) and Fig (2.2) are outlines of the profiles that may be constructed according to the invention . Fig 2.3 shows a perspective view of the device of the invention with multiple slots (6) wherein the fastening element is interwoven along the planar device FIG.3 depicts few embodiments of fastening elements that may be employed in the according to the present invention. Figure 3.1 represents a buckle whereas 3.2 and 3.3 represents Velcro elements, Figure 3.4 represents a zip tie inset of Figure 3.4, depicts the mechanism of a reversible, reusable zip tie, Figure 3.5 depicts a snap fit lock.

FIG 4 depicts arrangement of fastening elements on the immobilization device according to the present invention. Fig 4.1 shows a fastening element that is stacked and Fig 4.2 depicts a fastening element that is rolled. Fig 4.3 and Fig 4.4 depict fastening elements that are stitched and glued on to the body of the immobilization device.

FIG. 5 depicts a different embodiment of the device of the invention, wherein the device is divided into two parts. Figure 5.1 depicts an embodiment wherein the device is a two part device and the two parts thereof are connected by ball and socket joint; Figure 5.2 depicts an embodiment wherein the device is given a sort of a v-shape so that the two parts of the device remain fixed and are usable as such; Figure 5.3 depicts an embodiment of the two part device wherein the two parts of the device are connected by a flexible member, whereas 5.4 depicts a connecting rod connecting the two parts of the two part device and 5.5 depicts an embodiment of the two part device wherein the two parts of the device are connected by a bellow structure.

FIG 6 depict certain further embodiments of the device Fig 6.1 depicts a two part device wherein the two parts of the device are connected by a splinter element and the device is in folded condition during storage and Fig 6.2 depicts the same device in use. FIG. 7.1 and 7.2 depicts an embodiment of the immobilization device of the invention with an injured leg strapped to the device.

DESCRIPTION OF THE INVENTION:

In accordance with a broader aspect, the invention provides a device for immobilization of an injured extremity, comprising: (a) a substantially planar body with a broad head portion and a tapering tail portion to approximate the shape of a limb, the body provided with a plurality of slots on either of its sides;

(b) a plurality of predetermined spaced apart fastening elements extending transversely of the body and adapted to anchor on the slots provided on the planar body wherein at least the slots at the head portion are placed in a manner such that the fastening elements provide adequate support to the limb.

The device of the invention thus comprises a planar body which approximates the shape and size of a human limb longitudinally and transversely. The device is generally flexible and in use cradles the injured part providing it stability and aptly securing the body part such that no further damage is caused to the injured/fractured portion until treated by a clinician. Further the device does not completely envelop the injured extremity, thus accommodating / the swelling, and also permitting easy examination of the injured part by the clinician, without the clinician having to remove or adjust the device in any manner.

The device is light weight and of semi-rigid construction and can be applied and used by any unskilled person. A typical device developed in accordance with the principles of the invention is depicted in figure 1. As shown in figure 1, the device comprises a semi-rigid substantially planar body 1. The body is provided with slots (6) spaced apart from each other at predetermined distances all along either of its sides. This head of the body portion is rather a rectangular or convex head (2). As can be seen from the figure, the head portion of the device is broader than the tail portion (5).

The device may be constructed from any disposable readily available supportive material. Another important property of the material chosen is that the material of which the device is constructed should allow maximum penetration of X-rays so that it is easy for the hospital authorities to X-ray the injured portion and thereby allowing visualization of the injured area without having to remove or adjust the device and thereby limiting the discomfort to the patient. Preferred materials include plastics, recyclable plastic, shape memory plastics, shape memory alloys, malleable alloys, aluminum, wire mesh, naturally occurring materials such as bamboo, reeds, paper mache, thermocol, recycled paper, corn starch paper, cardboard, corrugated boards and the like. Preferably and advantageously, the body is constructed of cardboard, which makes the body very light weight. The body portion is constructed so as to be semi-rigid and retain maximum strength for supporting the limb in transverse axis yet having sufficient flexibility in longitudinal axis and is not so hard that makes it difficult to handle the device. The cardboard may be made waterproof/impermeable to fluids by coating with resin or wax or other similar waterproofing/water-repellent material or just reinforcing a layer of plastic material or laminated. In particular, due care should be taken to ensure that the board is impervious to blood and other body fluids from any of its surfaces or through the ends of the board as well as to make the device weatherproof, and dry in rainy or moisture laden environment. Optionally and advantageously, the cardboard material may be coated with any microbicidal material or hypoallergenic materials. The interstices of the cardboard may also filled with waterproofing or microbicidal material or the like. The cardboard may be rendered water proof by a silicone sealant, shrink wraped with plastic sheet selected from medical grade plastic, ABS, polypropylene, polyethylene, polyurethane, polycarbonate, polyetheretherketone , or coated with latex or rayon.

It is preferable that the burst factor of the material (i.e. the bursting strength of the material in grams per square centimeter divided by the basis weight of the paper in grams per square meter) is in the ratio of 12 to 60 but most preferably ranging from 20 to 30. The cardboard used for preparation of the body portion is preferably corrugated. The cardboard selected may preferably comprise 3 to 15 layers, most preferably 3 to 7 layers. Further, advantageously, the cardboard used for the present invention may be such that the corrugation therein runs along the longitudinal axis of the cardboard and not across the width of the cardboard. In other words, the inventors have found that if corrugation runs along the longitudinal axis it imparts additional strength to the cardboard and the device as such, as compared to other materials. Further, factors such as the fluting of the corrugation and the spacing between the corrugations may be varied thereby enhancing the strength of the base material.

The head portion of the device is generally curved to acquire the shape of the upper part of the lower limb or upper limb. In particular, the head portion may be given a wedge shape or almost convex or rectangular shape so as to resemble the shape of upper part of human lower limb or upper limb. Further the upper portion of the device is broad enough to accommodate and take the shape of the human limb and tapers towards the tail portion. The shape of the device approximates the shape of a human limb for a better fit and support to the limb.

As depicted in figure l,the body of the device includes several longitudinal creases (7), running across the length of the device. Creases may be substantially parallel to each other.

The body of the device, on either side comprises a plurality of slots or apertures designed for anchoring fastening elements. The slots or apertures may be developed on the longitudinal axis and spaced apart from each other at various distances. The apertures themselves may be rounded or elongated in shape; preferably elongated along the longitudinal axis of the body of the device. The slots developed on either side of the body of the device may be increased or decreased to enable positioning the device and prevent the movement of the device during handling. There may be further slots to enable proper strapping of the limb to the device.

Towards the head portion, the slots and the fastening elements are placed in such a manner to form a circumferential sling to render maximum support to the upper part of the limb and prevent further dislocation of the injured bone.

The immobilization device of the present invention secures the injured limb with fastening elements against the planar shaped body. The fastening elements provide adequate support to areas below and above the fracture. Further fastening elements in the device are used to secure any injuries to upper part of the extremities such as the inguinal area. Such a support restricts the pull of muscles and proximal fragments and hence prevents abduction, evertion and external rotation of the bones thereby firmly supporting the injured extremity till they receive definitive care.

Further, the inventors have found that the apertures or slots may be advantageously arranged in a specific manner so as to equally distribute pressure and forces along the body of the device.

The slots are so spaced along the edges of the body portion of the device that adequate support may be provided to the limb above and below the fracture, regardless of the site of the fracture of the lower limb. Further, the position of the slots and the fastening elements are such that it renders adequate inguinal support.

The body portion of the device is rendered flexible along the longitudinal axis by developing creases of predetermined width. The creases may be stamped onto the cardboard so that the device as such can fold itself around injured body part and take the shape of the extremity. Preferably the device is provided with several creases which may be parallel to each other or placed at an angle to each other. The fastening elements used to fasten the injured extremity to the body of the device are anchored onto the slots or apertures on the device. The fastening element used may be such as gauze, Velcro, cable ties, ribbons, buckles, elastic belts, laces, zip ties, soft cloth, tapes and the like. Some of these elements are depicted in figure 3. The fastening elements (8) may be limited to the slots or may be interwoven along the length of the device as shown in figure 2.3 The intermittent slots may be preferably be provided along the middle portion of the device so that a singular fastening element may run along the slot edge to edge Preferably, the fastening elements are made of Velcro. The Velcro may be of any size, but preferably, the Velcro is such that it is designed to fit the slot. Preferably, the fastening elements are made of zip ties. The zip ties may be of any size, but preferably, the ziptie is such that it is designed to fit the slot.

The fastening elements may be designed so as to easily connect with each other, loosely but firmly hold the injured body part in place. As shown in figure 3.1 the fastening element may be a buckle or as in figure 3.2 and 3.3 a Velcro anchored on either sides of the body and connected to each other or 3.4 (and 3.5), a reversible, resuable zip tie. The fastening elements may be placed in the device to be loosely hanging or they may be self looped, rolled, folded or the like such that the fastening elements may be unfolded/stretched during the usage. The fastening elements may be arranged in different ways as shown and depicted in figure 4. As shown in fig 4.1 the fastening element is stacked and Fig 4.2 depicts a fastening element that is rolled. Fig 4.3 and Fig 4.4 depict fastening elements that are stitched and glued on to the body of the immobilization device.

The slots and the fastening elements are such arranged to also give an open access to the wounds and the said device is configurable in multiple directions thereby reducing any form of discomfort to the patient. In particular, the inventors found that maximum care must be taken at the site of the injury. By use of conventional devices, either the site of injury is completely wrapped up on all sides and not visible to the clinician for first examination; or the device is too loose and instead of holding the fractured portion in place, causes more damage. Hence in the device of the invention, the slots for anchoring the fastening elements especially towards the head portion are positioned and arranged in a specific manner. Two slots are arranged at an angle and placed directly opposite to each other so that the fastening elements when running through them run may cross whereby the pressure applied onto the injured portion is just appropriate and enough to stably hold the injured part in place. The said device has smooth edges to avoid cutting of skin or any form of irritation. Optionally, the device may be padded or a cushioning material may be added to prevent any pressure points.

In an embodiment, device of the invention may be constructed in two parts, i.e as a two-part device. In such a case the two parts of the device may be connected to each via a flexible element or a ball and socket joint or any other suitable connection by a connecting element (52). The connecting member may be a fixed or a movable joint. The connecting element may be movable element such as a malleable member, elastic, a ball and socket joint, a lock and screw device, key type mechanism, snap fit locks, internal hinge, adjustable joints and the like. An advantage of this type of construction is the device in this form is more flexible and provides special care to the knee, elbow and other joints. The connecting member may also be a fixed joint, which may advantageously provide more rigidity. Various other constructions may also be possible within the two-part device concept. Some of such variations include as shown in fig 6.1 a case wherein the two parts of the device are connected by a splinter element and the device is in folded condition during storage and Fig 6.2 depicts the same device in use.

FIG. 7.1 and 7.2 depicts an embodiment of the immobilization device of the invention with an injured leg strapped to the device.

Since the device is universal and not cut/restricted or limited to use for a specific limb or particular height or length, the same device can be used for the right or the left side of the limb by just flipping the device, for an adult as well as adolescents. The dimensions of the device may be suitably chosen so as to adapt the device to pediatrics. Because the device of the invention is not intended to come in direct contact with tissue , it does not require any sterilization. However, if desired, the device of the present invention may be disinfected or rendered sterile by ethylene oxide treatment or other suitable methods.

Various modifications that would be apparent to a skilled person may be made to the invented device. For instance, other supporting materials, such as a rod, stick, or other materials of a further rigid structure may be strapped along with the device to the injured limb, to add strength to the device, thereby preventing further damage to the limb by "difficult patients" such as disoriented, delirious, alcoholic, confused, combative, violent, hypoxic, patient in extreme pain and head injury patients. The supporting element member may be used to render extra support or prevent the bending of the device.

Additionally, more than one member of the device may be added to the patient at the same time to increase the strength of the support and like purposes.

Thus, the device of the present invention may be used in conditions such as but not limited to pre-hospital/ pre-treatment, or intermediate stage. The device will support the injured extremities/ limbs till the patient reaches hospital or till definitive care is given.

The device of the present invention is ergonometrically adjustable, of light weight, and suitable to be used in both right and left limb. By covering a few areas and by adequately distributing the forces of tension and pressure, the device of the invention provides adequate immobilization to the injured limb. Several difficulties are encountered in handling a patient at the accident site. Lower limb fractures are common injuries in several accidents, related to road injuries, sports injuries, fall injuries, occupational injuries and other such injuries. The injury patterns vary widely depending on the patients' age and mechanism of injury. Untreated fractures can lead to severe blood loss and later hypovolemic shock especially if open, and should be treated with effective hemorrhage control and immobilization device. In pre-hospital care, the care provider should be ready to handle a wide variety of fractures such as patella fractures, femoral shaft fractures, posterior hip dislocations, tibial fractures, femur and acetabular fractures and other fractures. Further, the fracture may occur in the right or the left limb. Notwithstanding, the age, weight and the height of the probable accidental victim is unpredictable. It is not possible for the care provider to have separate devices to handle each and every fracture individually. It is advantageous for the care provider to have one device to handle all fractures by the use of a single device as the space in the ambulance is very constrained. Hence the device must be adaptable to the normal parameters of a specific population group and allow for any ergonomic or anatomic adjustment.

During the transport of the patient to the hospital from the site of accident it is extremely important that the immobilization device provides the necessary support to the patient. Suspected fractures and dislocations should be immobilized without repositioning. It is needed to handle the victim gently, providing comfort and with minimal disruptions^". If the patient is already bleeding, time consuming assembly of the immobilization device may/will only delay reaching the patient to the hospital and thereby adversely subjecting the patient to increased risk. The invented device fulfils these requirements adequately. The immobilization offered by the invented device to the injured organ, i.e. the lower limb is very critical. The invented immobilization device offers an adequate support along the length of the fracture, and snugly fits around the length of the limb, and substantially arrests to its movement preventing possibility of any further dislocation. Most importantly, it is critical that adequate support is provided to the joints above and below the fracture. Equally important is the support of the inguinal area. Unstable and displaced pelvic ring disruptions cause significant deformity, pain, and disability. Inadequate support of the pelvic bone may lead to further complications which include any combination of rotational and translational deformities. Further, in patients with head injuries or alcoholic patients or patients who are unstable and subject to violent and unpredictable movement, the invented immobilization device is capable of being fortified, such that the patient does not dislocate/break the same.

Further once the lower limb is immobilized and the patient is brought to the hospital, the invented immobilization device is amenable to diagnostic examinations such as X-rays. Hence the invented immobilization device is capable of

1. immobilizing the bone, above and below the fracture,

2. immobilizing the joints, above and below the fracture

3. providing support in the longitudinal direction, across the length of the fracture

4. In case of compounded fractures, has enough space, so as not to push the protruding bone back into the body

5. Is amenable to being covered with bactericidal material or gauze so as to cover the wound and to prevent infection

6. Provides optimal balance between rigidity and flexibility.

7. Takes the current shape of the limb

8. Is radiolucent so that the immobilization device need not be removed during x-ray examinations

9. Is inexpensive, economic and disposable.

The device of the invention may be used for the immobilization of a lower limb, regardless of the patient's weight and left/right injury, and provides adequate support to the injured limb. The device is lightweight, strong, extremely inexpensive to manufacture, and can be penetrated by X-rays to eliminate unnecessary movement of the injured limb.

A typical device constructed as per the principles of the invention is shown in figure 1.

The longitudinal panel (1) is of a length of 400 to 1500 mm, more preferably the longitudinal panel is of a length of 900 -1300 mm for adults and adolescents and 750 to 900 mm for pediatrics. The width of the board at one end (2) is of 100 to 300 mm, preferably, 150 to 250 mm and at the other end (5 ) is 50 to250 mm, preferably 100 to 18000 mm. The width of the board after the bend at (3) is about 150 to 450 mm, more preferably 200 to 350. The creases are rendered along the longitudinal length of the board. The creases may be spaced (4) at a distance of 20 to 150 mm, more preferably the creases are spaced at a distance of 40 -80 mm.

The slots (6) in the longitudinal length of the board are of 25 to 100 mm in length, more preferably, 50 to 75mm in length. The width of the slots may be 0 to 20 mm in length, more preferably, 5 to 15 mm in length. The position of the slots is such that, when the fastening elements are placed, they provide adequate support to the injured extremity.

In another embodiment, the present invention includes a kit, comprising the immobilization device of the present invention along with optional elements such as rods, padding devices, extra fastening elements, a user manual and the like. Advantages of the device: -

• It is lightweight

• It is easy to apply

• It enables open access to injuries

• It is less painful

· It is eco-friendly

• It is radiolucent

• It is adaptable to different extremity shapes, sizes, and natural course of progress for different variants of injuries

• It is configurable in multiple directions

· It is cost-effective

The device of the present invention is advantageous over other devices available in the market. The various advantages of the device of the present invention are compared with that of other devices available in the market at Table 1. Table 1: Table comparing the device of the present invention with that of marketed devices.

SAM Vacuum Wooden Thomas Crammer Proposed splint splint Plank Splint wire invention

Immobilize for Moderate Good Bad Good Moderate Good long time

Affordable cost Bad Bad Good Moderate Moderate Good (for single use)

Quality of Bad Moderate Bad Bad Bad Good strapping

Angle Good Bad Bad Bad Moderate Moderate adjustment

Configurable Moderate Bad Bad Bad Moderate Moderate for all types of

patients and

joints

Radiolucent Moderate Good Bad Bad Bad Good

Easy to Bad Bad Bad Bad Bad Good apply/remove

for wound

examination Disposable Bad Bad Good Bad Bad Good

Quick for Moderate Moderate Bad Bad Bad Good paramedics

Claims

1. A device for immobilization of an injured extremity, comprising: a. a substantially planar shaped body with a broad head portion and a tapering tail portion, the body provided with a plurality of slots on either of its sides; b. a plurality of spaced apart fastening elements extending transversely of the body portion and adapted to anchor on the slots present on the planar body; wherein at least in the slots are placed in a manner such that the fastening elements provide adequate support to the limb.

2. A device as claimed in claim 1, wherein at the head portion the slots are arranged at an angle to the body portion.

3. A device as claimed in claim 1, wherein the device is constructed of a material selected from plastic, recyclable plastic, shape memory alloy, malleable alloys, aluminum, wire mesh, naturally occurring materials such as bamboo, reeds, paper mache, thermocol, recycled paper, corn starch paper, cardboard or corrugated boards.

4. A device as claimed in claim 1 and 3, wherein the material of construction of the said device is preferably of cardboard.

5. A device as claimed in claim 1 and 3, wherein the material of construction is corrugated and comprises of multiple corrugated layers sandwiched between different planar layers.

6. A device as claimed in claim 1 and 5, wherein the corrugation in the material of construction runs along the longitudinal axis.

7. A device as claimed in claim 1 , wherein the planar body in complete or the ends or the interstices of the corrugation is coated with resin or wax or microbicidal material or hypoallergenic materials or laminated or rendered water proof by a silicone sealant, shrink wraped with plastic sheet selected from medical grade plastic, ABS, polypropylene, polyethylene, polyurethane, polycarbonate, polyetheretherketone , or coated with latex or rayon.

8. A device as claimed in claim 1 , wherein the fastening elements are selected from gauze, Velcro, cable ties, fabric belts, ribbons, buckles, elastic belts, laces, soft cloth, tapes, preferably, Velcro.

9. A device as claimed in claim 1 and 8, wherein the fastening element is reversible, reusable, fastener.

10. A device as claimed in claim 1 and 8, wherein the fastening element in the device is loosely hanging, self looped, rolled or folded, threaded or glued through the breadth of the device.

1 1. A device as claimed in claim 1, further comprising a supporting element such as a rod, plate, wires, or woven structures.

«

12. A device as claimed in claim 1 , wherein, the two members of the device are connected by a connecting element selected from a malleable member, elastic, or a mechanical joint, a ball and socket, revolute, pin, a lock and screw device, key type mechanism, snap fit locks, internal hinge, or live hinge.

13. A kit comprising the device as claimed in claim 1 along with accessories selected from a group comprising of rods, padding devices, extra fastening elements.

14. A device for immobilization of an injured extremity as claimed in claim 1 as substantially described herein the specification along with the figures.