The present disclosure is directed to powered orthotic devices for hand extension. In at least one example, the present disclosure relates to an automated therapeutic device for heating and extending a patient's curled fingers.
Patients with Cerebral Palsy and other neuromuscular conditions often experience hypertonia, a muscular condition that causes affected muscles to become tense. The tension causes pain and can often render the muscles ineffective for normal use. Most patients undergo extensive therapy to mitigate the pain and to regain mobility in the affected muscles.
Most therapies for hypertonicity in the hands and fingers include using splints to reduce the return of muscle tone between appointments with a physical therapist. Static splints use stretching forces to force the patient's hand into a static position for long periods of time. However, using these splints may lead to joint deformation, muscular atrophy, and pressure sores, while doing little to improve the patient's mobility. Alternatively, dynamic splints use resistive forces to counteract contractions of the patients' hand and avoid the harmful side effects that static splints may cause. However, no known device uses extending elements to act as pseudo-fingers while simultaneously providing therapeutic heat to help alleviate pain and improve mobility. As presented herein, an automated therapeutic device may provide for optimal heating and extending of a patient's curled fingers.
Provided herein is an automated therapeutic device for heating and extending a patient's curled fingers. The device may include a rigid base that extends from the patient's hand to the patient's elbow, a plurality of fingerlets, each operable to attach to one of the patient's fingers, a plurality of extending elements, each operable to reversibly attach to the rigid base and reversibly attach to one of the plurality of fingerlets, and/or a heating element operable to reversibly attach to the rigid base and to distribute heat along the patient's forearm.
Further provided herein is a method for extending a patient's curled fingers and therapeutically applying heat to the patient's forearm. The method may include placing an automated therapeutic device on a patient's hand, supplying power to the device, where the amount of power supplied is sufficient to cause the extending elements to extend the patient's fingers. The automated therapeutic device may include a rigid base that extends from the patient's hand to the patient's elbow, a plurality of fingerlets, each operable to attach to one of the patient's fingers, a plurality of extending elements, each operable to reversibly attach to the rigid base and reversibly attach to one of the plurality of fingerlets, and a heating element operable to reversibly attach to the rigid base and to distribute heat along the patient's forearm.
Other aspects and iterations of the invention are described more thoroughly below.
The description will be more fully understood with reference to the following figures and data graphs, which are presented as various embodiments of the disclosure and should not be construed as a complete recitation of the scope of the disclosure, wherein:
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the examples described herein. However, it will be understood by those of ordinary skill in the art that the examples described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features of the present disclosure.
Several definitions that apply throughout the above disclosure will now be presented. The terms “coupled” or “attached” defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “substantially” is defined to be essentially conforming to the particular dimension, shape or other word that substantially modifies, such that the component need not be exact. For example, “substantially cylindrical” means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The terms “comprising,” “including” and “having” are used interchangeably in this disclosure. The terms “comprising,” “including” and “having” mean to include, but not necessarily be limited to the things so described.
Provided herein is a device used to extend the curled fingers of a patient suffering from neuromuscular disorders including hypertonic cerebral palsy, while also providing therapeutic heat to the patient's forearm. In some examples, the device may include a rigid base extending from a patient's hand to elbow, a plurality of fingerlets, each operable to attach to a finger of the patient, a plurality of extending elements, each extending element operable to reversibly attach to the rigid base and reversibly attach to one of the plurality of fingerlets, and a heating element operable reversibly attach to the rigid base and distribute heat along the patient's anterior forearm.
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The device may further include an electrical system for supplying power to the device.
Further provided herein is a method for extending the curled fingers of a patient while also providing therapeutic heat. The method may include placing the device described herein on a patient's hand and supplying power to the device. The power provided to the device may extend the extending elements and/or heat the heating element. This may be accomplished by the patient or with the assistance of a caregiver.
The fingerlet design used an elastic perforated neoprene to accommodate the adjustability range of 0.5 to 0.6 inches in finger diameter. While it was initially expected that a Velcro adjustable strap would be needed in conjunction with the elasticity of the perforated neoprene to meet adjustability requirements, the elasticity of the material alone allowed sufficient adjustability for the user. In one example, the fingerlet was designed to be 1.3 inches in length by 1 inch in width. These dimensions were selected to ensure the fingerlet remained secured to the finger during extension.
The fingerlet releasing mechanism ensured that the tendons were immediately released from the user's finger if a rapid contracture occurred, allowing the fingers to return to a relaxed configuration. This was achieved by using magnetic button snaps to connect the finger to the extension tendons and allowed for full extension. Because every case of spasticity is different, the strength of the magnetic button snaps used should match the spasticity of the user. Disk magnets were also considered for use in the releasing mechanism, but the disk magnets tended to cause a premature release of the tendon due to the shear force created during extension.
To secure the device to the user's hand, an elastic strap stretched across the palmar region of the hand. The strap was then secured with button snaps. This configuration ensured that the rigid structure of the device was flush against the skin, allowing extension of the tendons to be fully transferred to the fingers.
The device was secured to the forearm using two Velcro straps that fixed both the rigid structure of the device and the thermal pad to the forearm.
The tendons were fixed to the device by using two button snaps. Button snaps were the preferred method for fixating the tendons because the strength of the button snaps was greater than the upward force exerted by the tendon during extension, preventing the tendon from detaching from the device when extension occurred.
Extension wires were secured to the device by using two Velcro straps made of the elastic perforated neoprene. The straps were positioned such that the extension wires left the device near the elbow.
A rigid thermoplastic material was used to support the hand. The rigidity of the thermoplastic provided the support needed for the tendons to extend the fingers to 180 degrees. The thermoplastic could also be molded to fit any hand or forearm. The thermoplastic material covered the top surface of the user's forearm and continued distally to cover the user's wrist and hand. The thermoplastic material was perforated, which allowed for comfort and breathability, particularly when the device was heated. A perforated neoprene material was sewn to the top surface of the thermoplastic to give the device a sleek appearance, and also provided a surface to place button snaps and straps to the device.
A thermal pouch contained the thermal pad that supplied heat to the forearm and acted as a barrier between the thermal pad and the skin. The thermal pad was made of perforated neoprene, which allowed the pouch to stretch when the thermal pad was inserted and ensured that the thermal pad fit tightly in the pouch. The dimensions of the thermal pad were also configured such that the thermal pad fit tightly in the pouch.
The device used four tendons to extend each of the user's fingers. The tendons were comprised of nitinol fiber wrapped in insulated nichrome wire. Further, the tendons were encased in a protective silicone tube and perforated neoprene sleeve. The tendons were fixed to the user interface via button snaps. Additionally, heat-shrink tube was used to hold the fibers and wire in place as they were inserted into the silicone tube.
The heating subsystem was comprised of a thermal pad that included a nichrome wire, a resistance temperature detector (RTD) that monitored the internal temperature of the thermal pad to assist in power regulation, and insulation made of felt and neoprene. The nichrome wire generated heat using electricity. The nichrome wire was configured within the thermal pad in such a manner to provide even heat distribution throughout the external surface of the thermal pad while also providing enough room for the RTD to be properly installed. The RTD was placed in between the nichrome wires with approximately the same length of wire above and below the RTD. This configuration was optimal for the RTD device to provide an accurate temperature reading. Additionally, the nichrome wires and the wires from the RTD all exited the thermal pad at the same location. This allowed the wires to be bundled together for convenience and for the user's mobility.
The thermal pad material was felt and was placed in a pocket made of perforated neoprene and nylon. The felt layer was 1 mm thick and the neoprene/nylon layer was 2 mm thick. Heat generated from the nichrome wires thus transferred through the felt layer, followed by the neoprene/nylon layer, and then to the user's arm.
The device was powered by electricity drawn from a wall outlet. The AC power was transformed down using a step-down transformer and a full-bridge rectifier to DC power. The DC power was then run through a regulator board to provide four different, controllable voltages required for the device to function. The voltages were 8.0 V, 5.0 V, 3.5 V, and 3.3 V.
The controls system used a microprocessor's port system and the analog-to-digital converter. This allowed the microprocessor to control the device when the extension and heating subsystems were in use by using switches and relays connected to the microprocessor.
The electrical system was tested to determine whether the system would provide the required voltages of 8.0V, 3.5 V, 5.0 V, and 3.3 V to the device. The test was performed using a MU113 multimeter with an accuracy of ±2%. The multimeter leads were pressed against various points on the electrical system to read the voltage differences. Each of the required voltages was read and documented.
The extension system was tested to determine the amount of power applied to the fingers. Each tendon was bent at a 90-degree angle. The amount of time needed to straighten the tendon to a 180-degree angle was recorded. The distance traveled by the tendon was determined by multiplying the length of the tendon (4 inches) by π/4 radians (90 degrees). The maximum force exerted by each tendon was measured using a dynamometer. It was assumed that the force required to bend the tendon from 180 degrees to 90 degrees was the same force exerted when extending the tendon from 90 degrees to 180 degrees. This test showed that the device applied a maximum of 1 lbf*in/s of power to the fingers. This maximum value could be varied depending on the design of the device and the electrical input.
The thermal pad was tested to ensure it could maintain an external temperature of 110° F. (±2.5° F.) for at least 15 minutes. The room temperature during the test was 73° F. The temperature of the thermal pad was measured using a Thermocouple Thermometer HT-9815 with an accuracy of ±1° F. The probe of the thermometer was pressed to the external portion of the thermal pad that would contact the user's forearm. Power was supplied to the thermal pad to increase the temperature. Once the thermometer indicated that the temperature of the pad was 110° F., time was recorded and the temperature was monitored for 15 minutes. When the test ended, the device was turned off. The results showed that the thermal pad was able to maintain a temperature of 110° F.±4° F. for 15 minutes. The temperature ranged from 108.5° F.-113.7° F. during the test.
The thermal pad was also tested to ensure that it could maintain an external temperature of 125° F. (±2.5° F.) for at least 15 minutes. The room temperature during the test was 73° F. The temperature of the thermal pad was measured using a Thermocouple Thermometer HT-9815 with an accuracy of ±1° F. The probe of the thermometer was pressed to the external portion of the thermal pad that would contact the user's forearm. Power was supplied to the thermal pad to increase the temperature. Once the thermometer indicated that the temperature of the pad was 110° F., time was recorded and the temperature was monitored for 15 minutes. When the test ended, the device was turned off. The results showed that the thermal pad was able to maintain a temperature of 125° F.±3° F. for 15 minutes. The temperature ranged from 122.2° F.-127.4° F. during the test.
The extension and heating subsystems were tested to ensure that power to those systems could be quickly cut off by the user. The test was performed using a MU113 multimeter with an accuracy of ±2%. The leads of the multimeter were placed where the extension and heating loads run. The voltages running through the leads were recorded. The switches controlling the extension and heating loads were flipped. It took approximately one second for the multimeter to indicate the voltage dropped to 0.00V. It is noted that the multimeter specifications indicate that the multimeter changes its display every 0.5 seconds, so the voltage drop could have occurred faster than indicated.
The thermal pad was tested to determine the time it would take to reach an external temperature of 110° F. The room temperature during the test was 73° F. The temperature of the thermal pad was measured using a Thermocouple Thermometer HT-9815 with an accuracy of ±1° F. The probe of the thermometer was pressed to the external portion of the thermal pad that would contact the user's forearm. Once the thermal pad temperature was equal to the room temperature, power was supplied to the electrical subsystem and time was recorded. The thermal pad reached an external temperature of 110° F. in 49 seconds. Next, the thermal pad was tested in the same manner to determine the time it would take to reach an external temperature of 125° F. Using the same materials and methods, the results showed that the thermal pad reached an external temperature of 125° F. in 75 seconds.
The device was tested to determine if it could accommodate the proper dimensions to fit children between the ages of 4 and 11. First, the device was tested to determine if the fingerlets would accommodate fingers that were 2-3 inches in length. This was tested using a wooden articulating hand model and a ruler. The results showed that the fingerlets could not accommodate this broad range of finger length without the degrading the level of extendibility of the tendons. Thus, the fingerlets were designed to match the dimensions of the articulating hand's fingers, rather than to adjust to finger lengths of 2-3 inches. Second, the device was tested to determine if the fingerlets could accommodate finger diameters of 0.5-0.6 inches. This was tested using a wooden articulating hand model and a ruler. A single fingerlet was placed on the articulating hand's fingers having diameters of 0.5, 0.55, and 0.6 inches. The fingerlet did not slide off of the articulating hand's fingers when extension occurred. This showed that the fingerlets could successfully accommodate fingers having diameters between 0.5-0.6 inches. Third, the device was tested to determine if it could accommodate a forearm length of 6-8 inches. This was tested by putting the device on a user with a forearm length of 8 inches and using the adjustable straps to secure the device to user's forearm. The device successfully fit to the user's forearm. Because the device was shorter than 6 inches in length, it was assumed that the device would fit a user with a forearm 6 inches long. Last, the device was tested to determine if it could accommodate a forearm with a diameter of 1.625-2 inches. The device was tested by placing it on a user with a forearm 2 inches in diameter, and then placing it on an articulating hand model with a wrist diameter of 1.3 inches. The device fit properly on both the subject and on the articulating hand model, indicating that the device would fit forearms with diameters of 1.625-2 inches.
The weight of the device was determined using a Cole-Parmer 6 kg Scale (±0.00005 pounds). The scale indicated that the device weighed 0.332 pounds.
The thermal pad was tested to determine if it could with withstand a maximum external temperature of 150° F. The room temperature during the test was 73° F. The temperature of the thermal pad was measured using a Thermocouple Thermometer HT-9815 with an accuracy of ±1° F. The probe of the thermometer was pressed to the external portion of the thermal pad that would contact the user's forearm. Power was supplied to the thermal pad to increase the temperature. Once the thermal pad reached a temperature of 150° F., a timer was started and the thermal pad continued to receive power for an additional three minutes, at which point power would be turned off. The external temperature reached a maximum of 198° F. during the test and the thermal pad showed no signs of damage.
The device was tested to determine how long it would take a user to learn how to competently operate the device. A timer was started and a person who had not seen the finished prototype was given an explanation of the device's functions and how the device could be adjusted to fit the user. The person was then asked how to apply heat settings, how to adjust the device, and how to apply extension to the fingers. Once the person gave correct answers to each of the prompts, the timer was stopped. The results indicated that it took the person 3 minutes and 39 seconds to learn how to competently operate the device.
The device was tested to determine how long it would take a user to correctly put on the device with the assistance of a caregiver. A timer was started and the device was given to a user. The user and a caregiver worked to put the device on the user's hand. Once it was verified that the device was properly placed on the user's hand and forearm, the timer was stopped. The results showed that the device could be properly placed on a user's hand with the help of a caregiver in 1 minute and 52 seconds.
The device was tested to determine the level of noise made by the device while being used. The noise level was determined using a data logging sound meter (±0.05 dBC). The device was placed on an articulating hand model and power was supplied to the device. Sound measurements were taken for 10 seconds with the device placed one foot away from the sound meter. The results indicated that the device operated at 42 dBC at one foot away.
This application claims the benefit of priority of U.S. Provisional Patent Application No. 62/888,172, filed on Aug. 16, 2019, the disclosure of which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/046450 | 8/14/2020 | WO |
Number | Date | Country | |
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62888172 | Aug 2019 | US |