Patent Application
20230121081
The present invention relates to devices and methods for testing hand function. In particular, the present invention is directed to devices and methods that measure dynamic forces exerted on a hand manipulated object, as well as a time-based measure of such forces, for use in clinical diagnostic and therapeutic applications.
Accurate hand sensorimotor function is important for the performance of day-to-day tasks that require dexterity. Fine hand motor control requires intact sensory information from the fingertips and the ability to execute motor commands, as well as the ability to integrate sensory information with motor commands (i.e. sensorimotor integration). Successful sensorimotor integration is the hallmark of hand function, and is responsible for critical aspects of manual function, such as precise motor control of force magnitude and direction of forces exerted by each digit on an object, as well as the ability to resist disturbances relayed on the hand-held object due to other digits and the environment.
An assessment of hand function measures a subject's skill in performing tasks with their hands. Hand function measurements of children may also be of clinical significance for identifying developmental pathologies, guiding treatments, and quantifying post-treatment progress. For example, a child's development or rehabilitation following a clinical treatment may be assessed by comparing the child's hand function performance to a baseline established from age normative data.
The most common pediatric dexterity tests include the Box and Block test, BOT-2 or Bruininks-Oseretsky Test of Motor Proficiency Ed. 2, PDMS-2 or Peabody Development Motor Scales Second Edition, the Shriners Hospital Upper Extremity Evaluation (SHUEE), Assisting Hand Assessment (AHA), Jebsen-Taylor Hand Function (JHFT) test, Functional Dexterity test (FDT), the ABILHAND-Kids, the Melbourne Assessment of Unilateral Upper Limb Function, the Quality of Upper Extremity Skills Test (QUEST), and Purdue Pegboard test. Most tests are extensive and take a considerable amount of time and expertise to administer and thus do not accommodate the short attention span of children with a wide range of cognitive and physical abilities. Some of these tests such as BOT-2, PDMS-2, QUEST, SHUEE, The Melbourne Assessment of Unilateral Upper Limb Function, and AHA provide a qualitative assessment of performance through observation (i.e., using a rating scale). However, they fail to quantify the quality of manual performance, and thus do not provide a truly objective assessment of dexterity. Other tests such as the Box and Block test, JTHFT, FDT, the Purdue Pegboard test focus on time-based measures of dexterity.
Time-based tests reflect on multiple aspects of motor control such as pre-shaping of the hand, grasping, transporting, releasing an object, strength, functional adaptations, eye-hand coordination, and the overall upper extremity movement. However, these measures are only a subset of functions necessary to manual activities, and do not account for information concerning the forces that a subject exerts on an object. Importantly, these conventional tests are also not sufficiently sensitive to identify subtle deficiencies in developmental hand function or small changes in hand function that may follow a clinical treatment.
A number of conventional Laboratory-based tests have attempted to quantify the development of digit force control in pediatric populations using sensors for measuring grip and load forces. Through a series of experiments, it was shown that at about two years of age children start demonstrating an adult-like grip and load force coordination strategy that continues to develop with age. By about eight years of age, the force coordination strategy nearly matches that observed in typically developed adults. It has also been shown that children with hemiplegia due to cerebral palsy have an impaired ability to coordinate their grip and load forces when compared with typically developing children. This impaired ability has been observed to improve, although not fully, with treatment. Further experiments have indicated that poor dexterity in children with cerebral palsy is due to impaired sensorimotor integration for digit force control. Conducting such a test in a clinical setting would be challenging. This test uses objects that are unfamiliar to children and therefore would require practice and extensive instructions. As a result, such a fine manual dexterity test may not be appropriate to assess children with short attention spans and those with a wide range of cognitive and physical abilities.
Thus, there remains a need for a device and method that provides a sensitive assessment of hand function in children, to measure the quality and control of movement (i.e., precision force control), and which is capable of doing so in a time efficient manner that is also effective for detecting deviations from the child's age norms.
A hand function testing device according to the present invention includes a base having a number of rigid wires protruding from a surface thereof, with each rigid wire being further provided with: a stationary bead affixed at a predetermined position along the rigid wire; a moving bead movably mounted on the rigid wire and movable along a working region of the rigid wire defined between a base-end of the rigid wire and the stationary bead, the moving bead being mounted on the rigid wire via reception of the rigid wire through a lumen in the moving bead; and at least one force sensing element for measuring a force input to the moving bead while the moving bead is moved within the working region of the rigid wire.
The hand function testing device may be provided with one, two or three or more rigid wires. When there are multiple rigid wires, each rigid wire will have a different configuration from one another based on differences in at least one of: a difference in shape of the rigid wires; a difference in positioning of a stationary bead at positions along the rigid wires; a combination of difference in shape and positioning of a stationary bead.
The at last one force sensing element may be any of a force sensing element positioned at the base-end of the rigid wire and adapted to measure a force input to the moving bead based on the transmission of an input force to the moving bead and through the rigid wire (e.g., a strain-gauge based load cell transducers); a force sensing element embedded in the surface of the moving bead and adapted to directly measure a force applied to a surface of the moving bead (e.g., a force-sensing flexible resistor); or a force sensing element embedded internally within the moving bead and adapted to directly measure a force applied to the moving bead based on a change in an electromagnetic field (e.g., an electromagnetic sensor). Any combination of two or more of the foregoing sensing elements may be employed. Preferably, the one or more force sensing elements are adapted to measure a force input to the moving bead in three separate axes.
In use, a subject moves a moving bead along a corresponding rigid wire, and force inputs to the moving bead are measured while the moving bead is moved within a working region defined between the base-end of the rigid wire and the stationary bead mounted thereon. The force input is measured over a period of time spanning from an initial bead contact up to a bead-to-bead impact, the initial bead contact corresponding with detection of a first force input to the moving bead following a state of rest, and the bead-to-bead impact corresponding with a first detected contact of the moving bead with a stationary bead. Preferably, measurements are made for force inputs to at least two separate moving beads on at least two separate rigid wires, each rigid wire having a different configuration from one another.
When the hand function testing device is adapted to communicate with a separate system for transmitting, recording, and/or assessing test results, then use of the hand function testing device further includes receiving the measurements of force inputs to the one or more moving beads on the one or more rigid wires at the separate system, the received force measurements informing of force input for moving the one or more moving beads within a working region of the one or more rigid wires.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. The accompanying drawings are included to provide a further understanding of the invention; are incorporated in and constitute part of this specification; illustrate embodiments of the invention; and, together with the description, serve to explain the principles of the invention.
Further features and advantages of the invention can be ascertained from the following detailed description that is provided in connection with the drawings described below:
The following disclosure discusses the present invention with reference to the examples shown in the accompanying drawings, though does not limit the invention to those examples.
The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential or otherwise critical to the practice of the invention, unless otherwise made clear in context.
As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Unless indicated otherwise by context, the term “or” is to be understood as an inclusive “or.” Terms such as “first”, “second”, “third”, etc. when used to describe multiple devices or elements, are so used only to convey the relative actions, positioning and/or functions of the separate devices, and do not necessitate either a specific order for such devices or elements, or any specific quantity or ranking of such devices or elements.
The word “substantially”, as used herein with respect to any property or circumstance, refers to a degree of deviation that is sufficiently small so as to not appreciably detract from the identified property or circumstance. The exact degree of deviation allowable in a given circumstance will depend on the specific context, as would be understood by one having ordinary skill in the art.
Use of the terms “about” or “approximately” are intended to describe values above and/or below a stated value or range, as would be understood by one having ordinary skill in the art in the respective context. In some instances, this may encompass values in a range of approx. +/−10%; in other instances, there may be encompassed values in a range of approx. +/−5%; in yet other instances values in a range of approx. +/−2% may be encompassed; and in yet further instances, this may encompass values in a range of approx. +/−1%.
It will be understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof, unless indicated herein or otherwise clearly contradicted by context.
The terms “individual”, “host”, “subject”, and “patient”, as may be used interchangeably herein, refer to a mammal, including, but not limited to, primates, for example, human beings, as well as rodents, such as mice and rats, and other laboratory animals. References herein to “children” will also be understood as interchangeable with the foregoing terms.
Recitations of value ranges herein, unless indicated otherwise, serve as shorthand for referring individually to each separate value falling within the respective ranges, including the endpoints of the range, each separate value within the range, and all intermediate ranges subsumed by the overall range, with each incorporated into the specification as if individually recited herein.
Unless indicated otherwise, or clearly contradicted by context, methods described herein can be performed with the individual steps executed in any suitable order, including: the precise order disclosed, without any intermediate steps or with one or more further steps interposed between the disclosed steps; with the disclosed steps performed in an order other than the exact order disclosed; with one or more steps performed simultaneously; and with one or more disclosed steps omitted.
The present invention is inclusive of diagnostic and therapeutic devices and methods that task a subject (e.g., a child) with manipulating an object by hand, and measure dynamic precision control of digit forces exerted on the object during performance as well as a time-based measure for performance of the task. Generally, the child is tasked with moving a number of small objects from corresponding first locations to second locations and performing these tasks under three separate difficulty conditions of low, medium, and high. The child's performance is measured to obtain a comprehensive assessment for use in detecting deviations in the child's development, which may include an assessment as to the effectiveness of a prior clinical treatment and the child's development or rehabilitation following such treatment. A child's performance is assessed by comparison to a baseline established from normative data for their age range.
An example of a hand function testing device 100, in the form of a bead-wire device, is shown in
The device 100 uses a number of wires 11 of different shapes. The wires 11 are made of polished steel with a diameter of 4 mm and are oriented to extend generally vertically from the corresponding top plates 12, and may optionally be colored coded. Each wire 11 is provided with both a stationary bead (SB) 15 that is statically affixed to the respective wire 11 and a moving bead (MB) 16 that is movably mounted on the respective wire 11 for sliding along the wire 11 under manipulation of a child. In the illustrated example, the stationary beads 15 have an outer diameter of 24 mm, and the moving beads 16 have an outer diameter of 18 mm. The moving beads 16 each have a lumen passing through a center thereof for sliding reception of the corresponding wire 11, the lumen having a diameter of 6.5 mm. The measurements from this example are non-limiting, and may be varied as needed. The measurements of the beads may also vary from one another in a single construction. For example, the outer diameter of the various beads may be made to vary from one another to provide differences in a required gripping force from one bead to another; this may be especially desirable for the moving beads 16 that are to be gripped by a child. Likewise, the lumen diameter of the moving beads 16 may be made to vary from one another to provide differences in a required force for translating a moving bead 16 along a wire 11. Preferably, the outer surfaces of the moving beads 16 are provided with a textured surface that minimizes accidental/unwanted slippage, so as to provide a more accurate testing of a child's grip and manipulation of the bead itself.
The several wires 11 in the device 100 are each provided with varying configurations, based on the shape of the wire 11 itself as well as the positioning of the stationary beads 15 along the wire 11. The complexity of the task in translating a moving bead 16 along a wire 11 will be determined based on both these factors. The region of a wire 11 along which a moving bead 16 may be translated may also be referred to as a working region. In the illustrated example, a first wire 11a is provided with a stationary bead 15a positioned approximately 100 mm from a base-end 111a at the corresponding top plate 12a to define a working region of a single length extending straight in a single direction, thereby defining a so-called “straight wire” of relatively low complexity. A second wire 11b is provided with a stationary bead 15b positioned approximately 170 mm from the base-end 111b at the corresponding tope plate 12b to define a working region with a single curve that divides the wire 11b into two separate lengths, thereby defining a so-called “single curve wire” of relatively medium complexity. A third wire 11c is provided with a stationary bead 15c positioned approximately 300 mm from the base-end 111c at the corresponding top plate 12c to define a working region with multiple curves, specifically three curves in this instance, that divide the wire 11c into three separate lengths, thereby defining a so-called “multi-curve wire” of relatively high complexity. In the illustrated example, the base-ends 111 of the three wires 11 are spaced approximately 90 mm apart.
Optionally, each moving bead 16 and/or stationary bead 15 may be provided with a force-sensing flexible resistor embedded under the outer surface. When provided, such surface-embedded resistors may directly measure a pressure that a child applies on a moving bead 16, and/or a contact force between a moving bead 16 and a stationary bead 15. As a further option, each moving bead 16 may be provided with an internal electromagnetic sensor for tracking a motion of the bead along the corresponding wire 11.
In some example, the device 100 may be made with multiple beads provided on a single wire; variations to surface texture and/or dimensions of the beads and/or wires; variations in outer diameter of beads and/or wires; variations in the dimensions of the lumens in the beads; and any combination of the foregoing. In some examples, the device 100 may also be provided with a motivational feedback system that further incentivizes children to interact with the device. For example, the device 100 may be made with one or more contact sensors provided in one or more moving beads 16 and/or a stationary beads 15 that is in communication with a sensory feedback system that is adapted for providing feedback to a user of the device 100 by outputting one or more of an audio signal (e.g., musical and/or other sound recordings), a visual signal (e.g., one or more lights of various colors and sequences, and/or other graphical displays), and/or a somatosensory signal (e.g., a vibration of one or more components of the device) upon contact of a moving bead 16 with a stationary bead 15. The device 100 may be further configured to enable intensity modulation of the feedback signals output by the sensory feedback system, for example, with one or more of an “OFF” setting in which no feedback signals are output, and “LOW”, “MEDIUM” and “HIGH” settings in which signals of respective low, medium and high intensities are output.
The load cell transducers 13, as well as any other optional sensing elements (e.g., surface embedded force sensors, internal electromagnetic sensors, etc.), will transmit measured data to a non-transitory storage medium that stores the data for subsequent analysis. The sensing elements may transmit data through any suitable connection, including wired or wireless, and any suitable program may be used for acquiring transmitted data (e.g., LabVIEW VI, National Instruments, etc.) and analyzing stored data (e.g., a custom-written script in MATLAB (R2020b)).
The device 100 may acquire a number of measurements of a child's performance in manipulating the moving beads 16 on the respective wires 11, including: a total force applied to the individual beads; a trial duration; and a force impulse (total force applied over the trial duration).
Initial bead contact may be detected by a corresponding load cell transducer 13 at a base-end 111 of a wire 11 based on a fluctuation in forces transmitted through the wire 11 from an otherwise steady resting state RS (i.e., a zero-state, corresponding with a force input of approximately 0 N). Preferably, the fluctuation that triggers detection of an initial bead contact is one representing a deviation from the resting state RS that is in excess of a threshold background noise level. Optionally, initial bead contact may be identified by a surface embedded force sensor based on detection of a threshold force level at a surface of the moving bead 16 and/or by an internal electromagnetic sensor based on detection of a threshold change in an electromagnetic field at the moving bead 16.
A bead-to-bead impact occurs when a child draws a moving bead 16 along the corresponding wire 11 to eventually contact the stationary bead 15 affixed to the respective wire 11. Bead-to-bead impact may be detected by a corresponding load cell transducer 13 at a base-end 111 of the wire 11 based on a fluctuation in forces transmitted through the wire 11 representing a sudden inflection in a force input curve and/or a change in a magnitude of force-input that exceeds a threshold level that is predetermined to coincide with an impact of a moving bead 16 against a corresponding stationary bead 15. This can be seen in
A trial duration TD, corresponding with a child's manipulation of a moving bead 16 along a single wire 11 is computed as the time from detection of an initial bead contact to detection of a bead-to-bead impact. The example in
In use, a child will be instructed to grasp a moving bead 16 and draw it over the corresponding wire 11 until it contacts a stationary bead 15 affixed in place at a predetermined location on the wire 11. A child may be instructed to slide the moving bead 16 along a wire 11 several times, either at a self-selected ‘comfort’ speed, or as fast as possible. Forces exerted on the moving bead 16, and through the wire 11, are measured using one or more of the aforementioned sensing elements. The detection of relatively low forces on the beads 16/15 and through the wire 11 will be informative of a well-coordinated hand function, whereas a detection of relatively high forces will be informative of low hand function. The inclusion of wires 11 with a number of curves will result in increased difficulty in traversing a moving bead 16 along the wire 11, which is expected to further accentuate any deficiencies in hand function. More complex wire shapes may also provide further insights in hand function through time-based and force-based measures in completing the task.
Interrater reliability of the device 100 was assessed through testing with nine typically developing children aged 4-15 years. Two independent researchers analyzed and rated the output of the device, and a third researcher calculated intraclass correlation coefficients (ICC) between the analyses of the two researchers. For the trial duration measure, it was found that the ICC between the analyses (absolute agreement) was 0.97 for the low difficulty condition, 0.99 for the medium difficulty condition, and 0.99 for the high difficulty condition. For total force measure, it was found that the ICC between the two analyses was 0.99 for the low difficulty condition, 0.99 for the medium difficulty condition, and 0.98 for the high difficulty condition. These results evidence excellent interrater reliability of the device 100 in measuring precision force control for a wide age range of children and adolescents.
Devices and methods according to the present invention yield a number of benefits over conventional hand function test devices and methods. Whereas conventional tests focus primarily on the time and speed of task completion and/or observation of behavior, devices according to the present invention measure force data that cannot be reliably derived from a time-based test due to a weak correlation between speed and force measurements. While some conventional hand function tests may provide force measurements, those tests typically use devices that are unfamiliar and unappealing to children, resulting in lower engagement by a child during testing, and thus less informative test results. In contrast, devices according to the present invention adopt a toy-like design that draws the attention of children to yields a stronger engagement, resulting in more informative test results. In addition, adoption of a bead-on-wire assembly provides the inventive device with a configuration in which the moving parts are retained on the device itself. This has the added benefits of not only simplifying storage and handling of the device, but also making the device safe for use with small children by avoiding any potential for a choking hazard that may otherwise accompany tests that employ loose, small parts.
Although the present invention is described with reference to particular embodiments, it will be understood to those skilled in the art that the foregoing disclosure addresses exemplary embodiments only; that the scope of the invention is not limited to the disclosed embodiments; and that the scope of the invention may encompass additional embodiments embracing various changes and modifications relative to the examples disclosed herein without departing from the scope of the invention as defined in the appended claims and equivalents thereto.
To the extent necessary to understand or complete the disclosure of the present invention, all publications, patents, and patent applications mentioned herein are expressly incorporated by reference herein to the same extent as though each were individually so incorporated.
The present invention is not limited to the exemplary embodiments illustrated herein, but is instead characterized by the appended claims, which in no way limit the scope of the disclosure.
The present invention was made with government support under grant number P2CHD101899, awarded by the NIH/NICHD C-STAR, at Shirley Ryan AbilityLab. The US government has certain rights in the present invention.
| Number | Date | Country | |
|---|---|---|---|
| 63255665 | Oct 2021 | US |
