NL2015467B1

NL2015467B1 - Intrinsic hand muscle functional force device.

Info

Publication number: NL2015467B1
Application number: NL2015467A
Authority: NL
Inventors: Olivier Bouwmans Floris
Original assignee: Floris Bouwmans
Priority date: 2015-09-18
Filing date: 2015-09-18
Publication date: 2017-04-19

Abstract

The present invention is in the field of a device for measuring intrinsic hand muscle functional force and a method for measuring intrinsic hand muscle functional force. Such a device and method can be used to determine a relative status of functional force in a given hand, e.g. relative to the other hand or a group of comparable persons.

Description

FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION

One of the most important instrument we humans have are our hands, they distinguish us from other species, enable us to be actively present in the environment, these allow us to make and use tools to change the environment. The world we designed and build is focused on healthy people that can properly use their hands. For people who suffer from limited mobility or function, physiotherapists try to remediate and promote function and mobility in order to restore the quality of life. Through examination, diagnosis and physical guidance a physiotherapist assists his/her patients. In some cases it is useful to measure function and mobility during the rehabilitation process or in general to properly assess functionality, compare it with e.g. an initial phase and monitor progress. Remediating such disabilities typically starts with proper diagnosis and examination in order to setup an efficient and effective rehabilitation program. Measurements are useful while conducting a diagnosis or examination and can support progress decisions or progress evaluations. It is noted that the hand is controlled by extrinsic and intrinsic muscles, both having their own functions. A similar objective could be present for other purposes, such as sports and in particular climbing. A lot of handgrip dynamometers are currently available with the ability to measure the hand its strength. It is noted that various tests are available to evaluate function of different individual muscles in the hand. These tests may be combined with more overall measurements and assist in diagnosis, and examination. However there is to the knowledge of the inventor no instrument yet that focuses on the functional strength of the intrinsic muscles.

For proper understanding a summary of skeletal muscles involved is given below. Medical terms are used in their normal meaning.

The human hand consists of extrinsic and intrinsic muscles (see e.g. (1970) C. Long II, P.W. Conrad, E.A. Hall, S.L. Furler, Intrinsic-Extrinsic Muscle Control of the Hand in Power Grip and Precision Handling, The Journal of Bone and Joint Surgery). Recognizable from the name, the extrinsic muscles are located in the forearm. They provide strength and promote crude movements. Contrary, the intrinsic muscles are located in the hand itself and allow detailed movements but little strength. Intrinsic muscles can however functionally not be separated from the extrinsic muscles and vice-versa; the tendons from the intrinsic muscles are attached to the extrinsic muscles, and therefore extrinsic muscle motion control depends on the intrinsic muscles. Some extrinsic muscles are considered relevant in view of function and mobility of the hand, such as M. flexor digitorum superficialis, M. flexor digitorum profundus, M. flexor policis longus, M. extensor digitorum, M. extensor digiti minimi, M. extensor indicis, M. extensor policis brevis and M. extensor policis longus. In addition some intrinsic muscles are considered relevant, such as M. adductor pollicis brevis, M. adductor pollicis longis, M. adductor pollicis, Mm. lumbricales I-IV, Mm. interossei dor-sales I-IV, Mm. interossei palmares I-III, M. Adductor digiti minimi, and M. flexor digiti minimi. The intrinsic and extrinsic muscles closely collaborate and a role of the extrinsic muscles is to produce force and less fine movements contrary to the abilities of the intrinsic muscles; as a consequence tests on hand function will not completely exclude the extrinsic muscles from the outcome, as they closely collaborate with the intrinsic muscles.

Motion may typically be described using the following terms. When the human body is in a normal anatomic position and a thumb rotate towards the body this rotating movement is called pronation. Initially a hand palm is facing backward and a thumb points towards the body. When the hand rotates back to the normal anatomic position this motion is called supination. This can be interpreted as the opposite of pronation. Abduc- tion describes a motion that pulls a structure or part away from the midline of the body such as by spreading fingers or lifting arms. Opposite from motions that pull structures or parts away from the body, adduction relates to a motion that pulls a structure or part towards this center line of the body. Palmar flexion refers to decreasing an angle between the forearm and palm of the hand. Dorsiflexion describes a motion contrary to palmar flexion, when the angle between the dorsal side of the hand and forearm decreases. Flexion identifies flexing the muscles, for example when making a fist. And extension refers to the opposite of flexion, for example when stretching the fingers.

An example of a prior art test is the so-called M. Flexor Pollicis Brevis test which relies completely on a relatively subjective judgment of a person performing such a test. The same is true for the so-called matching tests, typically also dedicated to a single muscles or a small group of muscles. Even further some of these muscles have multiple functions, depending on the joint, flexing, adducting, abducting and/or extension. In addition some of these muscles are connected to the tendons of the extrinsic muscles, which means that their function cannot be separated from the extrinsic muscle . A prior art device for measuring, the Rotterdam Intrinsic Hand Myometer (RIHM), which is considered to relate to a golden standard, is able of measuring intrinsic hand muscle strength. It evaluates the strength per muscle and thereby is not directly related to the activity of the hand for which all muscles work together. Besides, evaluating all various muscles separate takes an excessive amount of time. The RIHM is therefore considered more useful if very precise and specific information with respect to a hand is required, such as in a specialized hospital.

Similar, but less sophisticated devices compared to the above RIHM, typically analogue types, relate to a handgrip dynamometer, a smedley, and a squeeze dynamometer, which measure extrinsic hand muscle function and partly intrinsic hand muscle function, in combination. These devices are therefore considered unsuited for measuring intrinsic hand functional force .

Another issue may be that dimensions of a hand, in its various aspects thereof, such as lengths of individual fingers and thumb, width of fingers, thumb and hand, etc., varies from person to person. Such makes it difficult to perform a test or provide a device that is functional and provides reproducible results over a whole group.

Hence there is a need for an improved and more efficient device and method for measuring intrinsic hand muscle functional force, which overcomes at least some of the drawbacks of the prior art, without jeopardizing functionality and potential advantages thereof.

SUMMARY OF THE INVENTION

The present invention relates in a first aspect to a portable intrinsic hand muscle functional force device according to claim 1. The device is portable in that it is relatively small, fits in a hand, is typically wireless, is light weight, and hence can be transferred from one place to another easily.

Throughout the description terms as "bottom" and "top", "left" and "right", and "upwards" and "downwards" may be interchanged, in so far as appropriate. As such the present device can be used up-side down, without any trouble, e.g. in view of a left-hand and right-hand measurement. The reference to a "strain gauge" is in principle also relevant to a reference to any suitable one directional sensitive pressure sensor or likewise force sensor. In addition the sensor needs to be sensitive in at least one direction, typically a "vertical" direction.

The present device relates to an ergonomic tool to assist e.g. physiotherapists with the examination and diagnosis and physical intervention of their patient to restore and improve their patient's quality of life. The present design does not measure all intrinsic muscles independently, but rather measures a functional strength, which strength mainly relates to the intrinsic hand muscle group; for example like when grabbing a flat object. In this way the functional strength can e.g. be compared to an average of a similar group of persons, or the strength of the other sound hand. Clearly such the present method has some inherent weaknesses e.g. in view of specific intrinsic muscles. Nevertheless, the results of the developed measurement would show any loss of strength.

The present inventor has developed multiple measurements to measure intrinsic muscle strength. The test that has been found most appropriate is a test that focuses on grip strength. Thereto the fingers are almost bent 90 degree regarding the dorsal side of the hand, which is found to exclude the extrinsic muscles from collaborating for as far as possible. Such a set-up is found to test functional strength. The setup tests the following muscles specifically; M. Flexor Pollicis Brevis, M. Adductor Pollicis, Mm. Lumbricales, Mm. Interossei Dorsales, and Mm. Interossei Palmares. For proper functional measurements of the intrinsic muscles in this setup it has been found important that the thumb remains extended/stretched, to exclude the extrinsic muscle (M. Flexor Pollicis Longus) as much as possible (see fig . 1) .

Surprisingly the present design can be used as a "one fits all" design, at least for adults or taller children. Thereto dimensional research was conducted. It has been found that the best results were obtained when the device is symmetric, a length of the longest finger, a hand width, a width between parallel thumb and fingers (see fig. 1), and thumb length are taken into account. In view thereof the present device has a thickness of 10-50 mm, preferably 15-40 mm, more preferably 20-35 mm, such as 25-30 mm. It is considered to have a somewhat smaller version for e.g. children having dimensions on a lower side of the ranges given.

In addition it has been found that the present design is very well capable of converting a pressure into a force, which is not considered trivial per se. Thereto the present device is preferably calibrated over a given force range, such as over a range of 0-500 N.

The present one directional sensitive pressure sensor (410) is selected from a strain gauge sensor, a hydraulic sensor, and a force sensitive resistor, preferably a strain gauge sensor. The sensor is preferably attached to the present device. For such a sensor all of the following characteristics should preferably be met. It has been found that a hydraulic sensor may have an easy read out of measurement values, is accurate if properly engineered, is durable and has a moderate (average) vertical displacement, but is rather costly, has a relative large size and is difficult to implement and may leak. It has been found that an strain gauge sensor may have an easy read out of measurement values, is accurate if properly engineered, is durable, has a below average vertical displacement, has a relative small size and is easy to implement, but is somewhat costly. It has been found that force sensitive resistor sensor is durable, is not costly, has a moderate vertical displacement, has a very small size and is easy to implement, but may have difficult read out of measurement values, and is not accurate enough over a required force/pressure range.

The present strain gauge relates to a sensor whose electrical resistance relates to the amount of strain of the device. So when the body on which it is fixed deforms due to applied force, the resistance of the sensor changes. The sensor typically comprises a very fine wire or metallic foil arranged in a grid pattern and therefore is directional sensitive. As the wire or grid deforms, either tensile or compressive forces, the resistance changes. To process the measurements and translate the results into accessible date, the sensor typically is calibrated or theoretically mapped. Calibrating the sensor is an accurate approach, because any potential other system deviations are processed as well. It has been found that especially a linear displacement is preferred. S-beam, double beam and planar structured sensors seem to fulfill the present objective with reasonable pricing .

Various prototypes of the present device have been developed, evaluated, and validated, including various shapes, size, performance, capability, reliability, and reproducibility. The present two segment device, wherein the two segments are placed at a specific distance, and grip portion were found to give the best results. The present device provides an ability to be applicable for all and vari ous patients for both left and right hands. A finite element method (FEM) was performed and demonstrated that the present construction is able of performing the measurement in the required range. These FEM simulations were performed with a specific (though not limiting) material: acrylonitrile butadiene styrene (ABS) plastic, which is cheap, light and stiff. Secondly the model was constructed in a fashion all molds are one-way to decrease production costs.

In view of characteristics a material of the top segment, bottom segment and mid segment may individually be selected from various materials, Preferably these materials are relatively light weight (a density of 0.8-3 g/cm3), a Young's modulus (DIN EN SIO 178; Idemat 2003) of > 1 Gpa, a tensile strength (yield strength, e.g. DIN EN ISO 527) of > 25 MPa, and a flexural strength (ISO 178:2010) of > 50 MPa. Suitable materials are plastics, such as thermoplastic and thermoset plastics, which may be mixed plastics (e.g. copolymers), and light weight metals. It is further preferred to select a material than can be used in casting, die casting, rotating casting, etc.

In an exemplary embodiment of the present device at least two strain gauges are present, wherein the two gauges are preferably located symmetrically with respect to a virtual central axis (50) of the device.

In an exemplary embodiment of the present device at least two sensors, preferably of which at least one is attached to the top segment and at least one to the bottom segment; put differently, one sensor is located "upwards" and one is located "downwards". Therewith each individual sensor experiences a force exerted in a triangular section, wherein a triangular section of a first sensor points towards the second sensor a triangular section of a second sensor points towards the first sensor (Fig. 3). It has been found that by the above mounting of the sensors by creating two shearing triangles allowed to only use two sensors instead of three. It is noted that it was not possible to exclude momentum, torsion and shear largely or fully from the measurement as the present strain gauge sensors do not provide two directional outputs. Nevertheless the sensors are located in a mode that the deviation cause by potential momentum is not affecting the accuracy excessively (worst case ± 5% relative). Therefore it does not jeopardize the measurement. This was supported by testing the mechanical prototype. The maximum displacement found with a load of 300 Newton force was found to be 1.4 mm for the mechanical prototype of fig. 3, that is without the support of the additional parts. A similar test was conducted to the other surface plate on which a force is applied with similar results; hence the force applied to the bottom or top segment did not make a difference in the outcome of the measurement performed. So surprisingly this layout compensate for potential flaws in the measurement device.

In summary the present intrinsic hand muscle functional force device (FFIHMM) provides the capability to measure functional intrinsic muscle strength, which may help a therapist or other medical practitioner to examine their patients. Results can be used to determine injury, evaluate rehabilitation progresses and gives objective means for communication purposes. Currently the instrument is able of showing differences between left and right hand. If similar data is available as from the extrinsic muscle tests; averages regarding strength, gender and age, can be used to compare the patient's ability to a national average.

Thereby the present invention provides a solution to one or more of the above mentioned problems.

Advantages of the present invention are detailed throughout the description.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates in a first aspect to a device according to claim 1.

In an exemplary embodiment the present device comprises a data port (500), such as an USB-port or the like for communication with the outside world, for charging the device, etc.

In an exemplary embodiment the present device comprises at least one indicator (700) . The indicator may in an alternative, or in addition, be provided on a physically sepa- rated device, such as a tablet, a smart-phone, a computer, etc .

In an exemplary embodiment the present device comprises a power supply, such as a battery, a capacitor, etc.

In an exemplary embodiment the present device comprises a read out, such as a screen, e.g. a small screen, having dimensions of 3-10 by 5-20 cm. An example is an LCD display, a LED display, an E-ink display, or an electrophoretic display .

In an exemplary embodiment the present device comprises a transmitter, preferably a wireless transmitter, for transmitting data to a further device, such as a computer, a storage medium, a smartphone, a smart watch, an I-pad or the like, etc. The transmitter may also be combined with a receiver, or as an alternative a receiver is present.

In an exemplary embodiment of the present device the top segment has a top surface area of 50-400 cm2, preferably 100-300 cm2, such as 200-250 cm2.

In an exemplary embodiment of the present device the bottom segment has a bottom surface area of 50-400 cm2, preferably 100-300 cm2, such as 200-250 cm2.

In an exemplary embodiment of the present device the at least one strain gauge is capable of measuring in a force range of 0-500 N, preferably 0-400 N, more preferably 0-300 N. If two or more strain gauges are present the force range may be divided of the two or more strain gauges. Typically an upper value is taken larger than e.g. have the value in case of two gauges, such as 300 N.

In an exemplary embodiment the present device comprises an inward bent grip section (80). The grip section improves the reliability and accuracy of the present device, and improves comfort for a user.

In an exemplary embodiment of the present device the inward bent grip section extends 0.5- 3 cm inwards, preferably 1-2.5 cm, such as 1.5-2 cm. Such a grip section improves the reliability and accuracy of the present device, and improves comfort for a user.

In an exemplary embodiment of the present device the two gauges are located 2-12 cm from the virtual central axis, preferably 3-7 cm, such as 4-6 cm. Likewise in an example the two gauges (410) are located 2-12 cm inwards from a grip position (80) of the device, preferably 3-7 cm, such as 4-6 cm. Testing and modelling has shown that such a distance provides reliable and reproducible results of a large range of forces.

In an exemplary embodiment of the present device a displacement of the at least one gauge is limited to 0.2-5 mm, preferably 0.5-3 mm, more preferably 0.8-2.5 mm, even more preferably 1-2 mm, such as 1.1-1.5 mm, e.g. 1.3-1.4 mm, i.e. limited to a displacement of o mm when no force is applied to a maximum distance as indicated when a maximum force (e.g. 500 N) is applied.

In an exemplary embodiment of the present device the grip portion (80) is asymmetrical with respect to the/a virtual axis. With a slightly asymmetrical layout of the present device and in particular the grip portion even better results were obtained; a left or right hand can hold the present device as such in a more natural manner.

In an exemplary embodiment of the present device the at least one strain gauge sensor is an electrical sensor.

In an exemplary embodiment of the present device a first sensor body (400) is attached to the bottom segment and wherein a second sensor body (400) is attached to the top segment. Therewith the at least two sensors each individually experience a force exerted in a triangular section (11,12), wherein a triangular section of a first sensor points towards the second sensor a triangular section of a second sensor points towards the first sensor. It has been found experimentally that such a layout provides even better results in terms of reproducibility, reliability, and also in ease of use.

In an exemplary embodiment of the present device a width (w) of the device is from 40-130 mm, preferably 80-125 mm, more preferably 100-120 mm, such as 110-115, and/or a length (1) of the device is form 50-150 mm, preferably 90-125 mm, more preferably 100-120 mm, such as 105-110, and a thickness of 25-35 mm, preferably 26-33 mm, more preferably 27-32 mm, such as 28-30. For a child version ranges are a width from 40-90 mm and a length of 50-100 mm.

For determining sizes of the present device use is made of DINED. DINED is a Dutch database developed at the Technical University of Delft. It gives an overview of several average sizes together with the standard deviation.

In an exemplary embodiment the present device comprises a mid-ring segment (250), the mid-ring segment being located in between and attached to the top segment and bottom segment.

In a model set-up, partly integrated into the final device the following was tested.

This subparagraph describes hardware for the measurement. First of all two load cells are installed, in both the prototype and more final model. These sensors are Wheatstone bridge configured, which means that a voltage difference is measured that corresponds to a certain applied force. This difference is very small and in order to use these outputs as inputs for the processor they are amplified. The sensors used are constructed for measuring a range from 0 to 150 N. When a load of 150 N is applied to the sensor it provides a voltage difference of 0.9 mV/V applied.

The INA125p31 amplifier of Texas Instruments is used in order to perform these amplifications in view of its accuracy. The amount of amplification is set by a gain resistor, e.g. a 200 Ω potentiometer. This way the gain could be easily set, based on a required amplification to use all 4096 steps of the potentiometer up to 3.3 volt on which the present Teensy 3.1 runs. A capacitor was installed from V+ to Ground to decrease the noise on the sensor output. A Teensy 3.132 was used to run a software program and to perform the calculations based on the sensor input and calibration. The Teensy is a tiny processor board, which provides EEPROM, ADC (simultaneous sensor readouts) and 12 bit analog inputs. The Teensy is controlled by and communicates calculated results to an optional touch screen or other (wireless connected) device. For a production model typically a power circuit is installed as well; it may be capable of recharg ing through an optional USB gate. Depending on a type of battery, a voltage boost converter or regulator is preferred. For the prototype a 9V battery circuit was used and adjusted with a TO220 5V voltage regulator. The present device may perform even better with additional noise and/or band-pass filters.

The present device typically comprises software. In an example the software is able of calibrating at least three points, writes these results to an EEPROM and retrieves it during e.g. a system boot. During testing the measurements never reached the full length of the possible range, and as a result the calibration was limited to an upper value of 100 N per sensor. This was found to require a higher gain on the amplifiers, but allowed the system to perform more accurate. Calibration could be performed with an accuracy of ±0.01 N (1 gram). From a software start page, a second calibration was done to adjust a starting point back to zero. In an example (fig. 5)a start button is touched and a test screen pops up. On the left side of said screen three LEDs are shown. A top red LED indicates that the test is pausing, a middle LED shows that the resting period is over and that a test can be run by showing green. A lower LED turns blue while the instrument is measuring. In a top right corner a scope is shown, that gives a view on force applied in time, but is not commented with results. After finishing three tests for the left hand followed by three tests for the right hand, the screen demonstrated the results. First of all it highlights a maximum force applied per test, so six in total. At the end an average is calculated based on the applied force during the entire three tests. This can be very beneficial for showing progress during training. VisiGenie, a software package that eases the programming, was used.

The software may further be used for various other functions. Example thereof are setting up communication lines, setting up communication with the LCD-screen, resetting the system, retrieving and storing values, start and stop functions, setting variables, calculations, identifying errors, logistics, testing, communication, representing da ta, identifying maximum and minimum values, adjustments, gathering sensor information, and so on.

When the present device was completely configured and installed, validation tests for proper functioning were conducted. By applying known weights, which were determined with a kitchen scale. The results revealed that the accuracy of the prototype already lies within ± 1 N accuracy. It was found that initially lower weights were less accurate; this could easily be corrected by the implementation of a third calibration point and this relatively excessive deviation was solved.

In a second aspect the present invention relates to a method of measuring intrinsic hand muscle functional force, comprising the steps of providing a measuring device, such as the present device, positioning a person in a neutral position, thereby assuring that further body action is limited as much as possible and the measurement relates specifically to measuring the intrinsic hand muscle function, preferably in a position wherein an arm is not supported and not in further contact with the body (free) and wherein the wrist is stretched (or straight) , placing a thumb of the person at a bottom side of the device and the fingers at a top side of the device, stretching the thumb and fingers fully to an extended position thereof, thereby limiting action of the extrinsic hand muscles, pressing the device by the thumb and fingers for a period of time, such as at a maximal possible force, and measuring a force exerted by pressing. Typically the result of the measurement is shown in a display and/or transferred to a further device.

In an example of the present method the period of time is 1-10 seconds, preferably 2-8 seconds, such as 3-5 seconds. It has been found that pressing over a longer time with a relatively constant force is difficult for at least some persons, and hence produces unreliable results. It has also been found that it takes some time (up to one second typical- ly) to reach a maximal force.

In an example of the present method the steps of pressing and measuring are repeated 2-5 times, with a resting period of 10-120 seconds. Such a repetition and resting period are found to improve the quality of the measurement.

In an example of the present method the measurement is repeated in order to obtain a measurement for the left and right hand. For sake of comparison a relative value a second reliable value is required. Despite that most people are left-handed or right-handed a relative force exerted by both hands is still comparable, typically falling in a range of ±10% relative. So for a first impression on the force exerted by the "test"-hand, which may be an injured hand or having incomplete function, a comparison between the two hands is typically found to be fine.

In an example of the present method the measurement is compared to at least one further measurement, the further measurement being selected from the right or left hand measurement respectively, from a measurement of a comparable person, from an average of a group of comparable persons, etc. In view of the above paragraph also further sources for comparison may be taken. These further sources, either taken alone or in combination, provide even better means for comparison and are typically more reliable and more predictable.

In an example of the present method based on the comparison a relative fitness status of the hand is determined. Such an outcome of the comparison may be used to decide on a person's capabilities, e.g. in terms of fitness to work.

In an example of the present method the comparison involves taking into account at least one of gender, age, weight, length, physical history, injury, and physical and mental health status. With respect to physical and mental health further measurements may be performed, such as on extrinsic hand muscles, but in principle also on any further muscle of the body. Such also includes testing of heart-lung functionality (aerobic/anaerobic). The present comparison may also take these further items into account and/or focus on these further items individually. It has been found that by gathering sufficient information, anonymizing said infor mation, and comparing individual information with a relevant (sub-)group, reliable results on the function of the intrinsic hand muscles can be obtained.

In an example the present method comprises a step of, based information obtained, providing a recovery program in case of insufficient functional force. Even though the present device and method provide a more overall type of measurement it has been found that for practical use selection of recovery programs based on said device and method is very much supported.

In an example the present method comprises a step of determining a relative intrinsic hand muscle functional force.

In an example of the present method the measurement is performed on a person with one or more of nerve damage in the lower forearm, whom lost intrinsic muscle functionality and/or mobility, having trouble while holding a flat object, with deep hand injuries, with a functional limitation, with a discontinuity, after surgery, after bone fracture in the wrist, after bone fracture in the hand, during revalidation, with a muscle disease, with a rheumatic disorder, with arthritis, and with arthrosis. It has been found that specifically these people benefit from the present device and method.

The invention is further detailed by the accompanying figures and examples, which are exemplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims .

EXAMPLES/EXPERIMENTS

The invention although described in detailed explanatory context may be best understood in conjunction with the accompanying examples and figures.

SUMMARY OF FIGURES

Fig. 1 shows a hand in flexed status.

Figs. 2a,b show a functional model layout of the present device.

Figs. 3a,b show a mechanical model of the present de vice .

Figs. 4al-c2 show top and bottom segment parts and mid segment of the present device.

Fig. 5 shows an example of an electrical layout.

Figs. 6a-f show examples of read-outs.

DETAILED DESCRIPTION OF FIGURES

Figure 1 shows a hand in flexed status. Therein the thumb and fingers are stretched in a parallel mode at a distance F. The muscles that are considered most relevant are M. adductor pollicis (not shown), M. flexor pollicis brevis (not shown), Mm. Lumbricales, Mm. Interossei Dorsales and Mm. Interossei Palmares.

Figs. 2a,b show a functional model layout of the present device. Therein a width w, a length 1, a thickness t and a grip portion 80 are shown (fig. 2b) In fig. 2a the model is shown in a hand, ready for measuring. For determining a size and shape of the grip portion it has been found important to take especially the muscles M. adductor pollicis and M. flexor pollicis brevis in to account.

Figs. 3a,b show a mechanical model of the present device. Therein a first and second triangular force section 11,12 are shown, as well as two strain gauge sensors 400. Also a space for an optional display 700 with one or more indicators is shown as well as a data port 500.

Figs. 4al-c2 show top and bottom segment parts and mid segment of the present device. All in top view and bottom view. Therein a virtual axis 50 is shown. In addition it is shown that the top and bottom segment may have reinforced hexagonal fillets.

Fig. 5 shows an example of an electrical layout. Therein potentiometers, load cells, gauge sensors, EEPROM's, CPU and power source are shown. When using the instrument an on/off switch is provided on the device 51. This enables a 9V battery to power the instrument, first through the TO220, which is a 5V regulator and protects the circuit from high-voltage damage. Two capacitors are provided for electrical stability. The 5V+ is than connected to all V+ labels on the schematics; in a similar fashion this is done for the V- to V-labels. After the instrument is switched on the yLCD 32PTU touch screen starts functioning and allows the user to set, configure, and use the intrinsic hand muscle meter, as described in this document. After a certain function is selected the touch screen sends a request to the Teensy 3.1, through the Tx, Rx line 52. After the Teensy 3.1 has received the request, it executes it and transmits the results back towards the touch screen, through the Rx, Tx line 53. In case the request involves performing a measurement the Teensy reads the A2 and A3 input, which inputs are connected to the two INAlfSp's. These are instrumental amplifiers and multiply the voltage differentials from the two Wheatstone bridge (temperature compensated) load cells to a readable level for the 12bit analog inputs. The level of amplification is set by the gain potentiometers, with a reach of 200 Ohm. In fact every load is continuously detected and processed by the INAlfSp's, but only processed when requested for first.

Figs. 6a-f show examples of read-outs.

In the figures the following items are shown: 100 present device 11 first triangular force section 12 second triangular force section 50 virtual axis 51 on/off switch 52 communication line 53 communication line 80 grip portion 200 top segment 250 mid segment 300 bottom segment 400 strain gauge sensor body 410 strain gauge sensor 500 data port 700 display with indicator 1 length of the device t thickness of the device w width of the device

The invention although described in detailed explanatory context may be best understood in conjunction with the accompanying figures.

It should be appreciated that for commercial application it may be preferable to use one or more variations of the present system, which would similar be to the ones disclosed in the present application and are within the spirit of the invention .

The following clauses are added to support searching of the prior art of the patent. 1. Portable intrinsic hand muscle functional force device (100) comprising a stiff top segment (200), a stiff bottom segment (300) movably attached to said top segment, the device having a thickness (t) of 10-50 mm, at least one directional sensitive pressure sensor (410) selected from a strain gauge sensor, a hydraulic sensor, and a force sensitive resistor, located in between the top segment and bottom segment, and a grip portion (80). 2. Device according to claim 1, further comprising a data port (500) . 3. Device according to claim 1 or 2, further comprising at least one indicator (700) . 4. Device according to any of the preceding claims, comprising a power supply. 5. Device according to any of the preceding claims, comprising a read out. 6. Device according to any of the preceding claims, comprising a transmitter, preferably a wireless transmitter. 7. Device according to any of the preceding claims, wherein the top segment has a top surface area of 50-400 cm2, and/or wherein the bottom segment has a bottom surface area of 5 0-400 cm2. 8. Device according to any of the preceding claims, wherein the at least one strain gauge sensor is capable of measuring in a force range of 0-500 N. 9. Device according to any of the preceding claims, comprising an inward bent grip section (80). 10. Device according to claim 9 wherein the inward bent grip section extends 0.5- 3 cm inwards. 11. Device according to any of the preceding claims, wherein at least two strain gauges are present, wherein the two gauge sensors (410) are preferably located symmetrically with respect to a virtual central axis (50) of the device. 12. Device according to claim 11, wherein the two gauges (410) are located 2-12 cm from the virtual central axis . 13. Device according to any of the claims 10-12, wherein the two gauges (410) are located 2-12 cm inwards from a grip position (80) of the device. 14. Device according to claim 13, wherein a displacement of the at least one gauge is limited to 0.2-5 mm. 15. Device according to any of the preceding claims, wherein the grip portion (80) is asymmetrical with respect to the/a virtual axis. 16. Device according to any of the preceding claims, wherein the at least one strain gauge sensor (410) is an electrical sensor. 17. Device according to any of the claims 11-16, wherein a first sensor body (400) is attached to the bottom segment and wherein a second sensor body (400) is attached to the top segment. 18. Device according to any of the preceding claims, wherein a width (w) of the device is from 40-130 mm, and/or a length (1) of the device is form 50-150 mm. 19. Device according to any of the preceding claims, comprising a mid-ring segment (250), the mid-ring segment being located in between and attached to the top segment and bottom segment. 20. Method of measuring intrinsic hand muscle functional force, comprising the steps of providing a measuring device, such as a device according to any of claims 1-19, positioning a person in a neutral position, placing a thumb of the person at a bottom side of the device and the fingers at a top side of the device, stretching the thumb and fingers fully to an extended position thereof, pressing the device by the thumb and fingers for a period of time, and measuring a force exerted by pressing. 21. Method according to claims 20, wherein the period of time is 1-10 seconds. 22. Method according to any of claims 20-21, wherein the steps of pressing and measuring are repeated 2-5 times, with a resting period of 10-120 seconds. 23. Method according to any of claims 20-23, wherein the measurement is repeated in order to obtain a measurement for the left and right hand. 24. Method according to any of claims 20-23, wherein the measurement is compared to at least one further measurement, the further measurement being selected from the right or left hand measurement respectively, or from a measurement of a comparable person, or from an average of a group of comparable persons . 25. Method according to claim 24, wherein based on the comparison a relative fitness status of the hand is determined . 26. Method according to any of claims 24-25, wherein the comparison involves taking into account at least one of gender, age, weight, length, physical history, injury, and physical and mental health status. 27. Method according to any of claims 20-26, further comprising a step of, based information obtained, providing a recovery program in case of insufficient functional force. 28. Method according to any of claims 20-27, further comprising a step of determining a relative intrinsic hand muscle functional force. 29. Method according to any of claims 20-28, wherein the measurement is performed on a person with one or more of nerve damage in the lower forearm, whom lost intrinsic muscle functionality and/or mobility, having trouble while holding a flat object, with deep hand injuries, with a functional limitation, with a discontinuity, after surgery, after bone frac ture in the wrist, after bone fracture in the hand, during revalidation, with a muscle disease, with a rheumatic disorder, with arthritis, and with arthros.

Claims

A portable intrinsic-functional-hand muscle force device (100) comprising: a rigid upper segment (200), a rigid lower segment (300) movably attached to said upper segment, the device having a thickness (t) of 10-50 mm has, at least one directional pressure sensor (410) preferably selected from a strain gauge sensor, a hydraulic sensor, and a pressure sensitive resistor disposed between the upper and lower segments, and a grip portion (80).

The device of claim 1, further comprising a data port (500).

The device of claim 1 or 2, further comprising at least one indicator (700).

Device as claimed in any of the foregoing claims, which comprises a power supply.

Device as claimed in any of the foregoing claims, which comprises a reading window.

Device as claimed in any of the foregoing claims, comprising a transmitter, preferably a wireless transmitter.

Device as claimed in any of the foregoing claims, wherein the upper segment has an upper surface of 50-400 cm 2, and / or wherein the lower segment has a lower surface of 50-400 cm 2.

Device as claimed in any of the foregoing claims, wherein the at least one sensor with a strain gauge is able to measure in a force range of 0-500 N.

The device of any one of the preceding claims, which includes an inwardly bent handle portion (80).

The device of claim 9 wherein the inwardly bent handle portion extends 0.5-3 cm inward.

Device according to one of the preceding claims, wherein at least two strain gauge sensors are present, wherein the two strain gauge sensors (410) are preferably positioned symmetrically with respect to an imaginary center axis (50) of the device.

The device of claim 11, wherein the two strain gauge sensors (410) are located 2-12 cm from the imaginary center axis.

The device of any one of claims 10-12, wherein the two strain gauge sensors (410) are placed 2-12 cm inwards from the handle portion (80) of the device.

Device as claimed in claim 13, wherein an offset of the at least one strain gauge sensor is limited to 0.2-5 mm.

Device according to any of the preceding claims, wherein the handle portion (80) is asymmetrical with respect to the imaginary axis.

Device according to one of the preceding claims, wherein the at least one sensor (410) with a strain gauge is an electrical sensor.

The device of any one of claims 11-16, wherein a first sensor body (400) is attached to the lower segment and wherein a second sensor body (400) is attached to the upper segment.

Device according to one of the preceding claims, wherein a width (w) of the device is 40-130 mm, and / or a length (1) of the device is 50-150 mm.

The device of any preceding claim, comprising a center ring segment (250), wherein the center ring segment is positioned between, and attached to, the top segment and the bottom segment.

A method for measuring intrinsic functional hand muscle force, comprising the steps of providing a measuring device, such as a device according to any of claims 1-19, positioning a person in a neutral position, placing a thumb of the person at the bottom of the device and the fingers at the top of the device, fully stretching the thumb and fingers to an extended position, pressing the device with the thumb and fingers for a certain period of time, and measuring a force exerted by pressing.

The method of claim 20, wherein the duration is 1-10 seconds.

A method according to any of claims 20-21, wherein the steps of pressing and measuring are repeated 2-5 times, with a pause of 10-120 seconds.

The method of any one of claims 20-22, wherein the measurement is repeated to obtain a measurement for the left and right hands.

A method according to any of claims 20-23, wherein the measurement is compared with at least one other measurement, the other measurement from respectively the right or left hand measurement, or from a measurement of a comparable person, or from an average of a group of similar people is chosen.

The method of claim 24, wherein a relative fitness state of the hand is determined based on the comparison.

The method of any one of claims 24-25, wherein the comparison takes into account at least one of gender, age, weight, height, physical background, injury, and physical and mental health state.

The method of any one of claims 20 to 26, further comprising a step of providing, based on information obtained, a recovery program in the event of insufficient functional power.

The method of any one of claims 20-27, further comprising a step of determining a relative intrinsic functional hand muscle force.

A method according to any of claims 20-28, wherein the measurement is performed on a person with one or more of nerve damage in the forearm, who has lost intrinsic muscle functionality and / or mobility, who has problems holding a flat object , with deep hand injuries, with a functional limitation, with an irregularity, after an operation, after a fracture in the wrist, after a fracture in the hand, during rehabilitation, with a muscular disease, with a rheumatic disease, with arthritis, and with arthrosis .