Patent Application
20240000586
The invention relates a prosthetic device in the form of an artificial hand, a kit of components for making the artificial hand and a method of making and installing the artificial hand on the arm stump of a person in need thereof. In particular, the invention provides an artificial hand that is of relatively low cost and easy to assemble from a kit of components. Additionally, the artificial hand can be relatively quickly and easily fit to the arm stump of a person in need thereof so that the person can wear and use the artificial hand immediately without excessive training or instructions.
Throughout history, humans have lost limbs as a result of accidents, military combat, illnesses, and hereditary defects. In the United States, approximately 2 million people have had amputation of an arm or leg. As medical science improved, various prosthetic limbs have become available. These prosthetics are artificial devices that replace missing body parts, and have been manufactured out of metals, plastics, wood, leather, carbon, polycarbonates, resins, and laminates. Artificial hands, in particular, have been made in a complicated and expensive fashion utilizing electronics and sophisticated parts to try to mimic the operation of a hand. This causes the cost of such items to be prohibitive for people in less affluent countries. Additionally, the use and maintenance of such prosthetics requires specialized training and experience. To the knowledge of the inventor, there are no low-cost artificial hand prosthetics that can function appropriately to assist disabled persons and enable them to use the hand to conduct various work activities. The present invention now satisfies this need.
The invention now provides an artificial hand for a person in need thereof comprising first and second palm members, each containing at least one finger component, with the palm members connected together for rotation between a first, closed position wherein the finger components of the palm members are interspersed together and a second, open position wherein the finger components are spaced apart to allow grasping of an object. The artificial hand also includes an alignment mechanism associated with the first and second palm members to guide rotation between the first and second positions, wherein the alignment mechanism comprises a tab member located on the first palm member and spaced sidewalls on the second palm member defining a slot therebetween, wherein the slot is configured and dimensioned to receive an upper portion of the tab member therein to facilitate rotation between the first and second positions.
To facilitate rotation between the first and second positions, a fastener is provided for connecting the first and second palm members together, wherein the fastener passes through the side walls and slot of the second palm member and through a lower portion of the tab member of the first palm member. Also provided is a biasing member operatively associated with the first and second palm members. The biasing member is configured and arranged for urging the palm members towards the first position. The biasing member is further configured and dimensioned to be stretched or elongated to allow the palm members and their respective finger components to move to the second, open position to receive an object and to secure the object between the finger components as the biasing member attempts to contract from being stretched or elongated. A force is provided to the palm members to overcome the force of the biasing member to move the palm members to the second, open position by stretching or elongating the biasing member. Thus, when the force utilized to stretch or elongate the biasing member is removed, the biasing member attempts to return to its original configuration and shape thus urging the palm members to move toward the first position. This enables enable the finger components to grasp the object or to secure the object between them.
The at least one finger component of the first palm member advantageously includes one finger component a portion which is elongated and arcuate. Also, the at least one finger component of the second palm member includes at least two finger components, each having a portion of which is elongated and arcuate. The arcuate portions are arranged on the respective finger components to face each other and define an opening therebetween when the palm members and finger components are in the second, open position. Preferably, the one finger component of the first palm member is interdigitated between the two finger components of the second palm member. If desired, a stop member can be provided for the first, closed position, wherein the tab member of the first palm member includes a wall that is configured and dimensioned to contact a rear wall of the slot of the second palm member such that engagement and contact of these walls with each other acts as the stop member.
For a light weight construction, the palm members are made of plastic with the fastener preferably being a horizontal bolt that passes through the side walls and slot of the second palm component and through the lower portion of the tab member of the first palm member with the bolt secured by a washer and nut. The first and second palm members preferably include a groove or recess on an outer portion thereof to receive a portion of the biasing member therein, and the biasing member preferably is a flexible, solid, natural rubber rod, cord or strap.
For improved gripping, the finger components of the first and second palm members may include pad members respectively located on the portions that are arcuate, distal portions of the finger components, or on both the arcuate portions and the distal portions of the finger components. These pad members are made of a compressible rubber or polyurethane material which provide a better grip on the objects to be held.
A base member is advantageously provided to support the palm members. This base member includes a first cavity at one end and a second cavity at the opposite end, wherein the first palm member includes a mounting extension extending below the tab member for placement into and securement to the first cavity of the base member. This fixes the position of the first palm member such that only the second palm member moves to the second position.
A pylon is advantageously provided for connection to the base member. The pylon has a first end which is received in and secured to the second cavity of the base member. This pylon preferably comprises a wooden dowel within a plastic tube. A coupling member is typically provided to facilitate application of the artificial hand to the arm stump of a person in need thereof. This coupling member has a cylindrical body, a cavity for receiving and securing thereto a second end of the pylon, and a closed base configured for attachment to the person's arm stump.
To facilitate opening of the finger components by overcoming the force of the biasing member, the artificial hand further comprises a grasping member operatively associated with the second palm member for moving that palm member towards or to the second, open position. Preferably, the grasping member comprises a pull cord, a first end of which is secured to the second palm member and a second end of which is associated with the base member. Advantageously, the second palm member or its respective finger component along with the base member each include a guide hole, wherein the pull cord passes through each guide hole, the first end includes a knot to prevent the pull cord from passing back through the guide hole of the second palm member, and the second end passes through the guide hole of the base member for grasping by the opposite hand of the user. The second end of the pull cord can be provided with a loop if desired to assist in pulling the cord to open the artificial hand.
The invention also relates to a kit for preparing an artificial hand for a person having a missing hand and a remaining arm stump, the kit having a plurality of components as described herein. The components of the kit are of low cost and assembly of the artificial hand is straightforward, such that the artificial hand of the invention can be made available to many persons in need thereof and in particular to those in underdeveloped or poorer countries.
Generally, the kit includes the palm members, the fastener, the biasing member, the base member, the pylon and the coupling member as described herein. For installation or application of the hand to a person's arm stump, the kit can also include a flexible sheath configured and adapted to fit on the person's arm stump; a casting sock of a fabric containing a water activated settable material that, after activation, is adapted to fit over the flexible sheath; and casting tape of a fabric containing a water activated settable material and provided in one or more lengths that, after activation, are capable of attaching the coupling member to the person's arm stump while also covering the flexible sheath. If desired, these installation components can instead be provided in a separate kit.
The invention also relates to a method for preparing artificial hand from a kit of the components for a person having a missing hand and a remaining arm stump, wherein the method comprises assembling the artificial hand by connecting the palm members with the fastener; placing the biasing member about the palm members; and inserting the first palm member into the base member. When a pull cord is to be included, the method includes placing the pull cord through the guide holes of the first palm member and base member so that the person can open the artificial hand by using his or her anatomical hand to pull on the pull cord. If desired, the free end of the pull cord can be provided with a loop to assist in grasping engagement.
And to install the prepared artificial hand on a person in need thereof, the method further comprises the additional steps of applying a fabric or cloth sock on the person's arm stump; applying a separator bag over the sock on the person's arm stump; applying the flexible sheath upon the sock and bag on the person's arm stump; activating the casting sock by immersion in water and applying the activated casting sock to the flexible sheath; providing the coupling member beneath the casting sock and separator bag with a base surface of the coupling member contacting the casting sock and separator bag; activating the casting tape by immersion in water; attaching the coupling member to the person's stump covered by the casting sock by wrapping the activated casting tape around the coupling member while also covering the flexible sheath; cutting the pylon to an appropriate length so that the artificial hand is positioned to match that of the anatomical hand of the person; and attaching one end of the pylon to the cavity of the coupling member and the other end to the artificial hand.
Preferred features of the invention are now provided upon review of the appended drawing figures, wherein:
A preferred embodiment of the artificial hand of the present invention is now described.
The palm members 100, 200 include lower portions that are connected together by a bolt 175 which is secured using a conventional lock washer and nut. Palm member 200 includes lower sidewall portions 215A, 215B that form a slot therebetween in which a lower portion of the tab member of the first palm member 100 can move to place the palm members in the closed position or in the open position. Pull cord 350 is provided to assist in moving the second palm member to the open position.
Artificial hand 20 is typically applied to the arm stump of a patient that has compete use of his or her other hand. Therefore, the patient can simply grasp the palm member 200 and pull it away from engagement with palm member 100 to provide the open position for grasping of an object. To facilitate this operation, however, a grasping member operatively associated with the palm member 200 is provided for moving that palm member towards or to the open position. This grasping member preferably comprises a pull cord 350 that advantageously is secured to guide holes 240, 340 respectively located in palm member 200 and base member 300 as shown. One end of the pull cord 355 can be provided with a knot so that that end of the cord will not be able to pass through guide hole 240 in palm member 200. The pull cord then extends through guide hole 340 in base member 300 and extends towards the person's arm. The free opposite end 365 of the pull cord can be grasped by the other hand 375 of the person. Pulling on pull cord 350 causes palm member 200 to be moved toward or into the open position so that the palm members can receive and then be secured about an object, such as a broom or other tool for conducting activities that would not otherwise be possible without the presence of the artificial hand. Hand 375 can grasp the free end of the pull cord whether it is straight or provided with a loop 385 as shown in
The finger components 105, 205A, 205B can grasp an object by release of the pull cord so that the biasing member 125 attempts to force the second palm member 200 to return to the closed position. As can be appreciated, if the object to be grasped is larger than the opening defined by the arcuate shapes of the finger components of the respective palm members, a secure grip about the object is achieved. It is also possible for the artificial hand to grasp a flat or rectangular object between the ends of the finger components of the palm members. To assist in the securement of that type object, a compressible pad member 130 is provided on the end of finger component 105 of palm member 100, while similar compressible pad members 230 and 235 are provided on the finger components of the second palm member. These pad members are typically made of a compressible rubber or polyurethane material.
Further details of the components of the artificial hand of the invention are best shown in
The details of palm member 100 are best shown in
The details of palm member 200 are best shown in
The details of base member 300 are best shown in
When so mounted, the base member cooperates with palm member 200 to provide a stop member that prevents movement of palm member 200 beyond a fully open position. This stop member is formed when a lower portion of ridge 255 engages wall member 330 of base member 300. Thus, palm member 200 cannot be rotated beyond the point where ridge 255 contacts wall member 330. Base member 300 also includes guide hole 340 which is configured to receive pull cord 350 as shown in
To make such a connection, a coupling member 300 is provided. This coupling member 400, which is best shown in
The coupling member 400 is connected to the base member 300 utilizing a pylon 500. Pylon 500 can be made of many different materials, including metal, wood, rigid plastic or other materials having similar structural features. For lowest cost, a wood dowel can be used. A better arrangement for pylon 500 comprises a wooden dowel 510 encased within a plastic tube 520, as shown in
To provide a lightweight device with sufficient strength, each of the palm, base and coupling members are made of a plastic material, with polylactic acid (PLA) being preferred with the components being 3D printed. Of course, other high strength plastic materials that can be molded to the desired shapes can also be used. Examples of such materials include ULTEM (polyetherimide), PEEK (polyether ether ketone), PPS (polyphenylene sulfide) and LCP (liquid crystal polymer). A skilled artisan can select the optimum plastic material for these parts from these or other plastic materials.
Each of the plurality of components is low-cost and is made from low-cost materials and/or manufactured at low-cost. Low-cost may refer to materials able to be purchased inexpensively from generally available materials that can be tailored or conformed to the person in need using readily available and simple manufacturing tools or machines. Thus, the kit allows the assembly and attachment of the artificial hand at relatively low cost in just about any location. It also is particularly useful for persons in low income or poverty areas. The artificial hand prepared from the kit is substantially less expensive compared to prostheses currently in the market which may cost between $5,000 and $50,000 or more. The kit generally costs less than $100, and the artificial hand prepared from the kit by a health care professional would cost than less $200. Therefore, the artificial hand prepared from the kit costs much less than an average-cost hand prosthesis in the current market. The artificial hand is also simple to assemble from the kit such that it can be assembled by a layperson, e.g., a family member or a friend, after reading the preparation steps and instruction details provided in the kit as described herein. The kits can also be provided at no cost by being donated to certain impoverished or war-torn areas. In those situations, the artificial hand would be provided at an even lower cost or even at no cost to persons in need that would otherwise not be able to obtain one.
For attaching the artificial hand to the person, a sock is first placed on the person's arm stump. The sock directly touches the person's arm stump and provides some buffer between the skin and the components to be attached, just like a sock worn on a foot provides cushioning to shoes which are worn on the foot. The sock is typically a fabric sock that may made of cotton, wool, nylon, acrylic, polyester, olefins (such as polypropylene), spandex, linen, or any combination thereof. The fabric sock may also be made of other materials that provide comfort to the person's arm stump. The sock has an open end and a closed end and is slipped onto the person's arm stump with the closed end positioned at the end of the stump. The sock is configured to be at least as long as the flexible shield that is to be later applied.
To protect the person's skin from contact with the casting sock, a separator bag is applied to cover the sock and the person's stump to provide a barrier to the additional casting materials that are to be added. The separator bag has a size or volume sufficient to cover the area on the sock where the subsequently applied casting sock will be applied. The separator bag preferably has a longitudinal length that is longer than that of the casting sock to be later applied. The separator bag is preferably made of a waterproof material, such as polyurethane, polyamide, polyester, polyolefin (e.g., polyethylene and polypropylene), fluoropolymer, or any combination thereof. Other materials and combinations having similar characteristics may also be used. The separator bag prevents the settable material of the casting sock and water from soaking the sock or contacting the person's arm stump. The separator bag is conveniently a plastic tubular bag.
Alternatively, a plastic film such as Saran® wrap can be used instead of the bag.
The artificial hand as well as a kit for assembling the hand will require additional components for connection of the artificial hand to the arm stump of a person in need thereof. These additional components include a flexible sheath or casting sock 700 as shown in
The cured casting sock can also be provided with a tape preferably made of rubber or an elastomeric material or of another material that has similar flexibility characteristics. A flexible synthetic stocking or expandable tube can also be used. This protects the casting tape from water or other environmental conditions.
The casting tape may comprise a fabric containing a water activated settable material. The fabric may be made of the same material as the casting sock or of a different fabric material that is sufficiently porous to hold the settable material. The casting sock is preferably made of polyester. The water activated settable material may comprise resin such as polyurethane resin, polyester resin, polyisocyanate resin, epoxy resin, plaster, or the like. The water activated settable material is preferably polyurethane resin. The casting sock is activated by providing water to it. In one embodiment, the casting sock is simply immersed in water for activation. Once activated, the casting sock is applied to wrap over the coupling member and at least part or all of the flexible sheath, the separator bag, and the sock when those components are positioned on the person's arm stump. When the casting sock is provided as a roll, after activation, the tape is unrolled and wrapped around the other components to attach them together to the person's arm stump. The water activated settable material may cure within minutes once activated which hardens the casting sock. The water activated settable material may also be considered as a water-curable material. The casting sock may be a casting sock manufactured by STS.
Table 1 is an illustrative flow chart for the method of preparing the artificial hand of the invention from a kit of components
As noted herein, there are a number of alternative steps that can be followed to assemble the artificial hand from a kit of these components. Instead of applying adhesive to extension member 180 of palm member 100 or into cavity 320 of base member 300, extension member 180 can be secured to cavity 320 through the use of screws or by drilling a through hole and using a fastener arrangement of a bolt, lock washer and nut. And instead of drilling holes in the pylon, the pylon can be adhered to the cavities of the base and coupling members using a suitable adhesive. When bolts are used, additional washers can be provided to prevent the bolt head or lock washers from damaging the plastic members that they contact. Additionally, a metal sleeve and be applied to the doles to prevent contact of the bolting with the various plastic components that it passes through. The pull cord is an optional component although in most cases it is preferred.
In another variation, the attachment of the pylon to the base and coupling members can be deferred until the point in time when the artificial hand is to be attached to the person. This enables the hand to be prepared before seeing the person in need such that the length of the pylon can be determined once the person is available. Of course, if the hand is assembled when the person is present, the steps in Table 1 can be followed.
Table 2 is an illustrative flow chart for the method of attaching the artificial hand of the invention to a person in need thereof
Other features of the components that are typically attached to a person's stump are disclosed in the kits of U.S. Pat. No. 10,376,390 and U.S. patent application Ser. No. 16/538,751, the entire content of each of which is expressly incorporated herein by reference thereto. This includes the parts that are placed on the person before attaching the artificial hand thereto.
All of the necessary components described herein are typically provided in a box or other enclosure along with any other common components such as fasteners, adhesives, instructions, etc. so that the recipient of the box has all of the necessary parts and information to assemble the artificial hand and to attach it to a person in need thereof. The kit also typically includes bolts, nuts, lock washers and flat washers as needed for fastening components together. Also, appropriate adhesives, which generally are thermosetting adhesives, along with fiberglass reinforcement are also included in the kits.
It is to be understood that additional embodiments of the present invention described herein may be contemplated by one of ordinary skill in the art and that the scope of the present invention is not limited to the specific and preferred embodiments that are disclosed. While specific embodiments of the present invention have been illustrated and described, numerous modifications may come to mind to a skilled artisan without significantly departing from the true spirit and scope of the invention, and the protection provided herewith is limited only by the appended claims and equivalents thereof.
This application claims the benefit of U.S. provisional application No. 63/367,288 filed Jun. 29, 2022, the entire content of which is expressly incorporated herein by reference thereto.
| Number | Date | Country | |
|---|---|---|---|
| 63367288 | Jun 2022 | US |
