Patent Application
20240050802
People with reduced hand mobility and/or strength due to medical conditions (such as post-stroke, ALS, injury, etc.) have difficulty performing activities of daily living (ADLs). Tasks such as personal hygiene, feeding, and recreation are either more difficult or impossible without assistance from either a device or another person.
Existing methods of augmenting or creating or restoring grasping function in the hands have disadvantages such as high weight, large size, high cost, or inadequate function. For example, traditional devices (such as simple, static hand braces) do not provide a dynamic grasp force and can not hold a variety of object sizes and shapes. In short, existing passive devices are primitive designs intended for only a minimal reclamation of normal hand function. They are usually rigid and do not provide any hand movement.
Newer, electric grasping devices offer dynamic grasp force and allow objects of different sizes and shapes to be held, but they are usually heavy, high-profile, cosmetically undesirable, have to be recharged, and expensive to own. Electric grasping devices can offer more function than existing passive devices, but they weigh more, cost more, and are usually much larger. They also require dedicated activation signals, such as switches mounted near the user's chin or electromyography (EMG) sensors, which have reliability issues and require special donning and doffing practices.
Furthermore, conventional grasping devices are designed around bulky and cumbersome materials and methods, such as thick hook-and-loop, thermoformed plastic sheet, metal electric actuators, and bent sheet metal. They usually require customization services from a clinician for each user to ensure a proper fit.
According to a first aspect of the present invention, a hand exercise device includes a first wrist bracelet; a second wrist bracelet removably coupleable to the first wrist bracelet; an actuator mounted on the second wrist bracelet with an extendable loop powered by the actuator, and a fingertip brace coupled to the first wrist bracelet.
According to a second aspect, a spring-actuated or motor-actuated string/cable/cord/strap is manually attached (using the other hand, or even the user's teeth) to the ends of one or more fingers across the palm-side of the hand and the force from that string/cable/cord/strap can bend the fingers to conformally wrap around objects. It can be unpowered or powered.
According to a third aspect of the present invention, a method of holding an object is disclosed. The method includes attaching a device to a wrist, the device including a first wrist bracelet; a second wrist bracelet removably coupleable to the first wrist bracelet; an actuator mounted on the second wrist bracelet with an extendable loop powered by the actuator; and a fingertip brace coupled to the first wrist bracelet; inserting one or more fingers through the fingertip brace and the extendable loop, and exercising the one or more fingers by alternately pulling the one or more fingers into a palm and relaxing the one or more fingers.
According to a fourth aspect of the present invention, a method of exercising one or more fingers is disclosed. The method includes attaching a hand exercise device to a wrist, the hand exercise device including a first wrist bracelet; a second wrist bracelet removably coupleable to the first wrist bracelet; an actuator mounted on the second wrist bracelet with an extendable loop powered by the actuator; and a fingertip brace coupled to the first wrist bracelet; inserting one or more fingers through the fingertip brace and the extendable loop, and exercising the one or more fingers by alternately pulling the one or more fingers into a palm and relaxing the one or more fingers.
Advantages of the above aspects may include one or more of the following. The device provides a dynamic grasp force while holding a variety of object sizes and shapes. Exercises with the device enable the reclamation of normal hand function. The device is flexible and supports hand movement. The device is slim, lightweight and low-profile, cosmetically attractive, does not need charging, and inexpensive to own. Rehabilitation can be done without a dedicated activation signal, such as a switch mounted near the user's chin or electromyography (EMG) sensors, which have reliability issues and require special donning and doffing practices. Due to the slim and easy-to-adjust features, the device can be used without any customization services from a clinician for each user to ensure a proper fit.
Further applications and advantages of various embodiments of the present invention are discussed below with reference to the drawing figures.
This device augments the strength of the user's hand by attaching to the hand and exerting forces to hold and grasp objects. The grasping function can be easily engaged and disengaged, and the device is low-weight and low-profile. This embodiment creates useful grasping force for the user while being low weight, low physical profile, high function, and low cost.
This invention combines many of the desirable functional characteristics from passive and active grasping devices. It offers dynamic grasping force and a wide variety of objects to be held while maintaining a lightweight and low-profile physical form. It is easy for users to carry around during the day and alleviates many of the functional challenges encountered by people with compromised hand strength and mobility. It is soft, compliant, and adjustable, so a proper fit is guaranteed for all human hands.
Turning now to the figures, elastic bracelet (1) is threaded through the rubber bracelet (2), creating an adjustable bracelet. Spring actuator (3) is placed in the rubber bracelet's center cavity. One end of the cable (4) is inserted into the spring actuator (3). The rigid circular loop (5) is attached to the exposed end of the cable (4). The loop at one end of the elastic strap (8) is attached to the elastic bracelets (1). The loop at the opposite end of the elastic strap (8) is attached to the back-most slot of the fingertip brace (6). One end of the elastic strap (7) is attached to one of the far-lateral slots in the fingertip brace (6). The other end of the elastic strap (7) is attached to the other far-lateral slot in the fingertip brace (6).
The bracelet fits onto wrists, discreetly under shirt cuffs and adjusts to fit any size. The fingertip brace fits onto the index and middle fingertips and adjusts to fit any size using the finger elastic strap. When the rigid circular loop is pulled (using the opposite hand), it draws cable out of the spring actuator. When the circular loop is placed over the hook at the front of the fingertip brace, the spring actuator exerts a retraction force through the cable, pulling the fingertip brace and fingers into a grasping position. The dorsal elastic strap pulls backwards on the fingertip brace, redirecting the cable's force back to the dorsal side of the bracelet, preventing the fingertip brace from being pulled off of the fingers. When grasping force is no longer needed, the rigid circular loop is unhooked from the fingertip brace.
During assembly, the rigid circular loop is snapped onto the fingertip brace hook to engage grasping force. The dorsal elastic strap is shorter, and connects to a second finger elastic strap wrapped around the fingers, behind the proximal interphalangeal (PIP) joint instead of the dorsal side of the bracelet. The spring actuator could feature a locking mechanism to enable manual or automatic locking the cable's force and position. The spring actuator could feature an additional mechanism to allow the user to manually add tension to the cable to achieve greater or reduced grasping force. The spring actuator could feature a damping or frictional element to slow down the speed of cable retraction to improve ease of use. The spring actuator could be replaced with a simpler, linear elastic element. The spring actuator could be replaced with a linear or rotary electric actuator that either directly (cable) or indirectly (linkage, hydraulic, pneumatic, magnetic) applies force to the fingertip brace. The cable could have a sleeve or coating that improves its frictional performance when in contact with objects being grasped. One or more of the strap components could be consolidated to fewer components made of fabric, rubber, or other flexible material. The fingertip brace could attach to more or fewer fingers. Different fingers could be selectively engaged or disengaged from the grasping force. The fingertip brace or rigid circular loop could feature a quick-release mechanism to allow the user to easily disengage the grasping force without the use of the opposite hand. The lock formed between the fingertip brace and rigid circular loop could be electrically or otherwise automatically controllable so that other forms of input (e.g. voice command, timer timeout, inertial sensor, temperature sensor, etc.) could be used.
In other implementations, the dorsal elastic strap could be shorter and connect to a second finger elastic strap wrapped around the fingers, behind the proximal interphalangeal (PIP) joint instead of the dorsal side of the bracelet. In yet other implementations, the fingertip brace and/or strap could be designed such that it sufficiently holds onto the fingertips without the need for the dorsal elastic strap. The fingertip brace and strap could be removed by placing a hook or equivalent attachment point on the dorsal side of the bracelet and pulling the cable all the way over the fingers and down the dorsal side of the hand and placing the rigid elastic loop over that hook. As the cable retracts, the contracting loop would squeeze the fingers into a grasping position. In that variant, the cable and/or dorsal side of the hand may have a coating, sleeve, or geometry that minimizes the contact pressure and shear force between the cable and the user's skin.
In alternative implementations, the spring actuator could be replaced with a simpler, linear elastic element. The spring actuator could be replaced with a linear or rotary electric actuator that either directly (cable) or indirectly (linkage, hydraulic, pneumatic, magnetic) applies force to the fingertip brace. More than one cable or functionally equivalent mechanism could be used per hand. The spring actuator could be replaced with some other method of generating cable tension, such as body powder (e.g. wrist flexion/extension, elbow movement, shoulder movement, the opposite hand, etc.). One or more of the strap components could be consolidated to fewer components made of fabric, rubber, or other flexible material. The fingertip brace could attach to more or fewer fingers. Different mechanisms could be used to connect the cable to the fingertips during grasping and releasing. Examples include magnets, carabiners, hook-and-loop, grommets, clips, screws, locks, etc.
To use the device, a user slips her hand through band 1 and assembles the device as described above to fit onto the user's hand. When it is desired to grasp on to something, the user can: roughly align the hand wearing the device with the object to be grasped; using the opposite hand, pull on the rigid circular loop to draw out a sufficient length of cable to wrap around the object and meet the fingertip brace; snap the loop over the hook at the front of the fingertip brace; the grasping is now engaged, and the object can be acted upon. When it is desired to let go of the object: using the opposite hand, gently pull upwards on the rigid circular loop to disengage it from the fingertip brace; the cable and loop will quickly draw back into the spring actuator.
While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein.
Each embodiment disclosed herein may be used or otherwise combined with any of the other embodiments disclosed. Any element of any embodiment may be used in any embodiment.
While the invention has been described by way of example and in terms of the specific embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
