WO2015121690A1

WO2015121690A1 - Device apt for measuring physical efficiency and power output of human running, walking and other movements in watts and a method for its usage, application and processes

Info

Publication number: WO2015121690A1
Application number: PCT/HU2014/000104
Authority: WO
Inventors: Sándor Erdélyi; Imre ERDÉLYI
Original assignee: Sándor Erdélyi; Imre ERDÉLYI
Priority date: 2014-02-16
Filing date: 2014-11-17
Publication date: 2015-08-20
Also published as: HUP1400078A2

Abstract

The subject matter of our invention is a device apt for measuring the physical efficiency and power output of human running, walking or other motions, which is made up of at least a measuring device fastened in or on a shoe (21) and/or on its sole (22) and a central measuring device that performs data transmission (2) with it, and an accelerometer (25, 51) and sensors (23, 31) suitable for measuring various physical parameters. Another subject matter of our invention is a method for the application of the device apt for measuring physical efficiency and power output of human running, walking or other motion caused by forces exerted by the lower extremity. A characteristic feature of our invention is that it has arithmetic unit (43, 48) apt for computing physical data of motions; a measuring device that is made up of a shoe unit (41) that is responsible for measuring the components of the force (15) emerging on the contact plane (11) between the sole (22) and the ground; the shoe unit (41) contains a transceiver unit (44) and a battery (45); furthermore the central measuring device is made up of a central unit (46) fastened close to the centre of body mass (17), which is apt for capturing velocity data; this central unit (46) is made up of a central transceiver (49) and a central battery (50). Fig, 1 is deemed as characteristic.

Description

Device apt for measuring physical efficiency and power output of human running, walking and other movements in Watts and a method for its usage, application and processes

The subject matter of our invention is a device apt for measuring physical efficiency and power output of human running, walking or other motion generated by forces exerted by the lower extremity, which is a combination of at least one measuring device that can be placed in or on a shoe or on the sole, a central measuring device that performs data transmission with the former, and accelerometers and sensors suitable for measuring various physical parameters. Another subject matter of our invention is a method for the application of the device apt for measuring physical efficiency and power output of human running, walking or other movement generated by forces exerted by the lower extremity.

There are several so-called power output measuring devices, in the field - among others - of sport or orthopaedics, which are used for measuring walkers or runners. Such methods are, among others, time measuring with stopwatch, distance measuring, speed measuring, acceleration measuring, step counting, pulse counting, blood pressure metering, video record analysing, etc. A common feature of these measurements is that none of them measures power output as it is defined in physics, but rather some sort of achievements and/or physiological features. Power output is understood as the work done in a unit of time. When motion is studied, it can be expressed with equation P=F * v and can be measured in Watt units. In this equation power P is the scalar product of force vector F and velocity vector v. Work is the product of force and distance travelled (displacement): W= * s. In the course of human running or walking, force F is exerted between the sole and the ground, velocity v and distance s can be measured with appropriate accuracy at or close to the centre of mass.

A solution described in a patent registered in Hungary under no. P0900341 measures forces that arise on the sole. Forces that arise between the sole and the ground on the contact surface are, as the foot rolls over, continuously measured by force measuring sensors expediently distributed on the sole surface.

Publication US20090235739 Al describes an energy expenditure measuring and foot motion tracking device. Tri-axial sensors built into a shoe-sole perceive the characteristics of the force vectors, acceleration and 3D angles of incline, which is followed by the calculation of the volume of energy expenditure in a given period. A device described in a French publication no. FR2873281 Al , wherein a sport shoe is equipped with sensors. These sensors measure various parameters that are processed, and then the device is able to determine the following: time, velocity, acceleration, velocity of metabolism, energy expenditure, spent calories and distance travelled.

All the above suggests that the exact determination of the momentary power output inevitably necessitates the measuring of force and velocity data as well as the foot's angle of incline, and the joint handling of data-triplets so composed. We know methods that observe the parameters of walking or running, that among others measure velocity, step number, distance, acceleration and pressure, however, none of these methods combines these data or calculates the power output with equation P=F * v, or determines physical efficiency.

The aim of our invention is the elimination of the deficiencies of solutions presented so far, and the creation of a device and a method that measures the work done and the momentary power output expended by a runner or walker. In physics work is calculated with equation W=F * s and power output with equation P=F * v . For measuring power output, a device is needed that is able to measure the components of force F that arises between the sole and the ground when one walks or runs, which are F_x that is heading the direction of movement, Fy that is sideway perpendicular to F_x and F_z which is perpendicular to the plane of the former two, and to measure motion as it proceeds, and the components of velocity vector v, namely v_x, Vy and v_z possibly at or close to the centre of the mass. A display accessory connected to our device can show the power output or other data measured. At least 200 measurements per second are targeted to ensure accuracy, although this number could be increased or decreased dependently upon the aim of measuring. Another objective is that the results measured could be used for calculating not only power output but also work done. Work done can be calculated like power output, when velocity vector is replaced by displacement vector. Expediently, the method should be apt for utilisation in sports, locomotion rehabilitation, motion studies, or physiological researches. Important aims are the measuring of three-dimensional forces emerging in the plane where the sole contacts the ground as the sole is rolling in the course of walking or running, measuring the path of locomotion and characteristics of this path such as distance and velocity, measuring the angle between the direction of the foot and the direction of movement, furthermore the calculation of power output, work done and efficiency.

The inventors' activity is based on the perception that the accurate determination of the momentary power output inevitably necessitates the measuring of the force and the work done as well as the angle of incline of the foot, and the joint handling of the resulting data-triplets. Power output can be measured if we know the components of force F that arises between the sole and the ground when one walks or runs, which are F_x heading the direction of movement, Fy sideway perpendicular to F_x and F_z which is perpendicular to the plane of the former two, as well as the velocity data. In order to determine velocity, the components of velocity vector v, namely v_x, Vy and v_z should be measured possibly at or close to the centre of the mass. Through the measurements taken, the useful and dissipated power output of a runner can be determined. This perception enables the calculation of work done similarly to power output; the velocity vector can be replaced with the displacement vector.

In view of the objective set, the subject matter of our invention will in general be realised according to Claim no. 1. The most generalised form of the method of application is explained in Claim no. 7. Specific realisation methods are described in sub-claims.

This device is suitable for measuring physical efficiency and power output of human running, walking or other movement generated by forces exerted by the lower extremity, which is a combination of at least one measuring device that can be placed in or on a shoe and/or on the sole, a central measuring device that performs data transmission with the former, and accelerometers and sensors suitable for measuring various physical parameters. A characteristic feature of the invention is an arithmetic unit apt for calculating motion's physical data; the measuring unit is made up of a shoe unit that should measure the components of the force emerging on the plane where the sole contacts the ground; this shoe unit contains transceiver unit and battery; furthermore the central measuring unit is composed of a central unit fastened close to the centre of the mass, apt for capturing velocity data; and this central unit contains a central transceiver unit and a central battery. Another possible design is when the central unit contains a central data storage unit, and the shoe unit contains a data storage unit. Also, a possible design is when the central unit is completed with a computer and/or info-communication device.

In the course of a customary utilisation of our invention, force measuring sensors placed on or in the shoe and/or on the sole measure the components of forces emerging on the plane where the sole contacts the ground, and the central accelerometer that form part of the central unit measures the velocity vector of the centre of the mass of the user; and in the knowledge of the force components and the velocity vector, the arithmetic unit will perform mathematical calculations using equation P=F * v in order to determine the physical power output (P) of human running, walking or other motion generated by forces exerted by the leg, and the results are displayed on a server that communicates with the central unit.

Hereunder our invention is explained in more detail with reference to a possible design, on the basis of charts.

To charts attached:

Fig. 1. lateral view of a human body with units fastened,

Fig 2/a lateral view of a human body in motion, with axes and directions relative to it, Fig. 2/b. axonometric chart of a shoe, featuring various vectorial components of the force,

Fig. 3/a is the lateral view of the shoe and the units of the device located thereon, Fig. 3/b. is the bottom view of the shoe and the units of the device located thereon, Fig. 4/a is the lateral view of the shoe and the units of the device located thereon, during a step cycle,

Fig. 4/b is the bottom view of the shoe and the units of the device located thereon, during a step cycle,

Fig. 4/c illustrates the forces and their components,

Fig. 5 illustrates the configuration of the shoe unit and the central unit.

Fig. 1 presents a runner in shoes 21 equipped with force measuring sensors 23 and supplied with a central unit 46. Data transmission 2 is performed between the central unit 46 and the unit fastened to the shoe 21. The central unit 46 should capture the results of all three measurements and in any given case should correct calculations dependently upon the type of motion. This chart visualises the fact that the useful work done and the momentary power output exerted by a runner or a walker is the product of v_x velocity vector 14 parallel with the direction of movement and F_x vector 1 exerted parallel with them. These components are measured in such manner that the force measuring sensors 23 fastened on the shoes 21 take a series of measurements thereby measuring as a vector F_x force 1 emerging on the sole of the user and v_x velocity vector 14.

Fig. 2/a presents data to be measured and the places where they are measured. Force data and velocity data necessary for measuring power output could be measured at the foot respectively at the centre of mass 17. This figure, in alteration of the previous one shows not only those base data that are necessary for calculating the useful power output but also those necessary for calculating effectless power output not serving locomotion, in other words: the power dissipation. From among the components of velocity vector 16, the component pointing to direction x interpreted in the coordinate system 12, i.e. the v_x velocity vector 14 has a direction identical with that of the direction of movement 13. Running is most efficient when the path of the locomotion 10 of the centre of mass 17 of the runner coincides with the direction of movement 13. Acceleration measured by us can be interpreted alongside the path of the locomotion 10. The first integral of the acceleration at a given point of the path of the locomotion 10 of the centre of mass 17 will be the tangent that meets the path at that point. Such tangent at the same time is the velocity vector 16 that can be decomposed along the axes of a coordinate system 12 used for measuring forces when its origin is moved to the centre of mass 17 thereby arriving at velocity vector v_x 14 and v_y, and v_z.

Fig. 2/b shows an axonometric image of the shoe 21. In the course of running or walking, feet exert forces F 15 to propel locomotion and these forces emerge on the plane where the foot contacts the ground. These forces, when they are illustrated in coordinate system 12 point to directions x, y and z, where axis x points to the direction of motion, axis y is perpendicular to x and is within the contact plane 1 1 , whilst z axis is perpendicular to both and points upwards. Our device is able to measure the components of force F 15 emerging during motion between the sole and the ground, namely F_x 1 pointing to the direction of movement 13, F_y 18 sidewise perpendicular to F_x and F_z 19 perpendicular to their plane.

Fig. 3/a is the lateral view of a shoe 21 forming part of the power output measuring device. Force measuring sensors 23 are in discretional number fastened to the sole 22 of the shoe 21. Fig. 3/b is the bottom view of the sole 22 of the shoe 21 equipped with force measuring sensors 23. The accelerometer 25 and the radial angle meter 26 fastened on the sole 22 of the shoe 21 take measurements on the basis of data produced by force measuring sensors 23. The force measuring sensors 23 are connected through expediently designed wires 28 to the shoe unit 41. The toe of the shoe 21 points to the direction of the longitudinal axis 27.

Figs 4/a and 4/b show the lateral and the bottom view of a shoe 21 equipped with our devices as it walks. In order to measure forces, force measuring sensors 23 were fastened to several points of the sole 22 of a shoe 21, and the data produced by all of the active force measuring sensors 31 will be taken into consideration in the calculation of the power output. A force measuring sensor 23 is an active force measuring sensor 31 when during the locomotion it is actually contacting the ground, thus there is a contact plane 1 1 where a coordinate system 12 with its origin in the centre of the sensor can be interpreted. Forces are interpreted only in the contact plane, separately for each active force measuring sensor 31 , in their respective coordinate systems. In order to avoid any computation error that could be caused by the inclination of the foot, the results should be corrected with the angle between the direction of movement 13 and axis x of the given sensor or the longitudinal axis 27 of the shoe worn.

Fig. 14/c shows that the direction of movement 13 does not coincide with the longitudinal axis 27 of the foot or the shoe. There is an angle of incline 32 between these two lines. In the course of calculations, this angle of incline 32 will also be determined. In the course of running or walking, the feet exert forces F 15 to propel locomotion. From the aspect of power output, only the forces exerted towards the direction of movement 13 are deemed to be useful, because those serve for the forward locomotion of a ainner or walker; the upward force serves for supporting the body and the lateral forces serve mostly the maintenance of the balance. A condition of the calculation of the power output is that we could be familiar with and could calculate two components of force F 15 emerging in between the sole and the ground, namely F_x 1 pointing to the direction of movement 13 and F_y 18 that is sidewise perpendicular to that.

Fig. 5 illustrates the positioning of the shoe unit 41 and the central unit 46 and the connections among various components. The shoe unit 41 should reasonably be composed of at least a data storage unit 42, an arithmetic unit 43, a transceiver unit 44 and a battery 45. The arithmetic unit 43 of the shoe unit 41 assigns the data so measured with identifiers that typically are codes identifying the measuring moment and sensor. Data are stored in the data storage unit 42 together with these identifiers. The arithmetic unit 43 can perform mathematical processes with data produced by the accelerometer 25, the radial angle meter 26 and the force measuring sensors 23. The data storage unit 42 temporarily stores measured and processed data. It may form part of a microprocessor or may be installed in an independent storage circuit. In response to the request sent by the shoe unit 41 , the arithmetic unit 43 will send data packages via the transceiver unit 44. The transceiver unit 44 and all electronic circuits are miniaturised and do not interfere with motion. The electronic circuit of the central unit 46 should reasonably be composed of a central data storage unit 47, a central arithmetic unit 48, a central transceiver 49 and a central battery 50. The central unit 46 can through the central transceiver 49 request measured and/or processed data. Also, it will control the operation of the central accelerometer 51 and the central radial angle metering sensor 52, will assign the measured data with identifying codes, and temporarily store them in the central data storage unit 47. The arithmetic unit 43 and the central arithmetic unit 48 can be suitable micro-circuits, micro-processors or micro-controllers or other logic circuits. The data storage unit 42 may form part of a microprocessor but might be installed in an independent storage circuit. The central arithmetic unit 48 will perform the appropriate operations and capture the processed power and other data in the storage unit. An expedient design of the central data storage unit 47 is an internal memory; another possible design uses a replaceable data media. The central unit 46 is responsible for capturing and synchronising measured results and perform further computation and data processing tasks if necessary.

In the course of the application of our invention, dependently upon the results wished to achieve, the power output measuring device will be equipped with the shoe unit 41 that can be fastened on the shoe 21 and with a central unit 46 that could be fastened close to the waist. Data necessary for taking measures are produced by the force measuring sensors 23, accelerometer sensors 25 and radial angle meter sensors 26 fastened on or in the shoe 21 , and at least one central accelerometer sensor 51 installed in the central unit 46. Force measuring sensors 23 are fastened at several points of the sole 22 of the shoe 21 , and the data produced by all active force measuring sensors 3 1 will be taken into consideration when the power output data is computed. Measurements will be taken with the help of direction data determined with force measuring sensors 23, 31 , accelerometer 25 and radial angle meter 26. Measurements could be acquired simultaneously, or in a succession with a frequency that does not interfere with the accuracy of the calculations, or there is a third method wherein the forces simultaneously exerted on the active force measuring sensors 31 are estimated by way of interpolating the results produced by successive measurements. There is a fourth method where data are sampled in a manner that is characteristic of digital devices and by way of approximate calculations a continuous function is fitted to the data sampled, and mathematical operations can be performed at any given point of such function. Increased number of sensors will improve accuracy. Accuracy of the computations can be further improved if the device is supplemented with an arithmetic unit located not on the body. Also, our device can be completed with computer or info-communication device, e.g. smart phone; and the central unit 46 can be supplemented with a displaying device, a video monitor for instance. With the help of the arithmetic unit 43 of the shoe unit 41 placed in the shoe 21 , identifiers (e.g. code identifying the measuring moment and sensor) can be linked to the measured data. Data together with such identifiers are stored in the data storage unit 42. On the basis of data produced by the accelerometer sensor 25, the radial angle meter sensor 26 and the force measuring sensor 23 installed in the right and left shoes 21 , the arithmetic unit 43 installed in the shoe unit 41 can determine the direction of movement 13 and - by way of identifying active force measuring sensors 31 - the contact plane 1 1 between the sole 22 and the ground, and can then determine the momentary coordinate system 12. Afterwards data produced by force measuring sensors 23, i.e. F_x 1 and Fy 18 pointing to directions x respectively y as well as data a_x, a_y and a_z produced by the accelerometer 25 are captured. From the acceleration data of the path of the locomotion 10 the projections of x-y, x-z and y-z planes can be computed. The next computation step will be the calculation of velocity figures v_x, v_y and v_z through integration or series expansion or other mathematical methods, and the next one will be the calculation of - e.g. integration - the characteristic data of the path of locomotion and its s_x, s_v and s_z components. The active force measuring sensors 31 acquire measurements roughly simultaneously, and data of forces pointing to the same direction are added up by the arithmetic unit 43. The best results can be achieved when measurements are broken down to small dots distributed over the entire surface of the sole 22, and the force measuring sensors 23 are installed at appropriately selected points, for instance at the end of toes, under the ball of foot, the heel or the lateral part of the foot. Our device can be operated with one single force measuring sensor 23, but sensors should expediently be installed at as many points as is necessary for precisely measuring forces distributed on the entire surface of the sole. The accelerometer 25 and the radial angle meter 26 installed in the shoe 21 produce basic data necessary for the determination of the angle of incline 32 of the foot. The central unit 46 captures the results of all measurements and dependency on the type of the motion, calculations may be corrected. For computing power output, when the direction of the movement is known, forces can be corrected through a mathematical transformation: rotation around the origin. In an expedient solution, velocity is measured with a tri-axial central accelerometer 51 placed on the median pointing to the direction of movement 13, which intersects or passes close to the centre of mass 17. In another expedient solution at least one accelerometer should be fastened anywhere on the body, provided that the movement of the centre of gravity and the direction of movement can be computed from the measurement results with appropriate mathematical procedures. The pace of measurements is adjusted to the pace of force measurements, or the measuring devices can be synchronised through continuous functions fitted to sampled data. Out of the measurements acquired by the central accelerometer 51 , the computations performed by the appropriately programmed central arithmetic unit 48 will separate vertical and horizontal extremes, determine the direction of movement 13 and the velocity vector 16. In the course the calculations we utilise the cyclically of locomotion. If the central accelerometer 51 could not be placed on the appropriate median, or if the type of the motion is such that the direction of movement changes continuously, then the movement of the centre of mass 17 can be estimated from the results produced by the central accelerometer 51 or the central radial angle meter 52 or from the combination of those results. For instance, two, three or more accelerometers and/or radial angle meters can be fastened on a belt, at appropriate distances from each other, and with the help of the acceleration or angle data computed by us we can calculate a centre that will define the centre of mass 17 located within the body. With customary mathematical procedures, the path of the locomotion 10 is transformed to the centre of mass 17 and this will be used for those calculations that are based on the centre of mass 1 7. Further calculations can be grounded on base data and computed data, for instance statistics can be compiled, or these data could be collated with other environmental or physiological data. Dependently upon the aim of the measurement, we can observe the two feet separately or together, the walking or the running, furthermore we could analyse and evaluate data. A step could be broken down to small phases, or statistics could be elaborated for an entire step cycle or for several steps or for a given duration measured.

The device described herein has several advantages. One of the advantages offered by our invention is that it assists in the interpretation of several things, for instance the momentary power output characterising a given point; changes in the momentary power output which means a series of comparisons among the measuring points as the foot is rolling; average power output during the rolling phase, which is the weighted or other arithmetical average of the momentary power outputs; the power output of a step-pair or the average output on a longer distance. All these can further be analysed with the use of further mathematical statistical methods. It is advantageous when the velocity vector is replaced with the dislocation vector, in this case the work done can be calculated similarly to the power output. Another advantage of our device is that the number and location of sensors is discretional and depend upon the aim of the application, the available space, the costs and the technical level to be applied, and other considerations, and should be conceptualised during designing a given product. Thus this device can be tailored to individual needs, is available for large layers of the society and can better be utilised. For instance, if accuracy should be improved, the units can be supplied with more sensors. Also, our device can be extended or its capacities can be enlarged by supplementing it with a computer or an info- communication device (e.g. smart phone). Also, a beneficial feature is that data can be transmitted in the radio-frequency range to a smart phone, a computer, directly to the internet, or any other discretionally selected device and could be processed there further. Radial angle meter and accelerometer sensors can be operated according to several physical principles, thus they can measure pressure, tension, bending, dislocation or acceleration with optic, magnetic, capacitive, ultrasound, inertia or any other principle; the essential thing is that the data produced by the sensors of the accelerometer and the radial angle meter could precisely produce the angle between the foot and the direction of motion, which is necessary for force measurement. The same beneficial feature can be found at the force measuring sensors. As long as the force data produced by the force measuring sensors provide base data for measuring power output, the physical principle used for the operations does not matter. A further advantage is that devices can be grouped, concatenated, replaced, extended or diminished in several ways.

In addition to the examples described in the foregoing, our invention could within the scope of patent protection be manufactured in various designs and through various manufacturing procedures.

Claims

1. A device suitable for measuring physical efficiency and power output of human running or walking or other motion, which is made up of at least one measuring device installed in or on a shoe (21) and/or on the sole (22) and a central measuring device that performs data transmission 2 with it; furthermore an accelerometer (25, 51) and sensors (23, 31) suitable for measuring various physical parameters, whereas it is supplied with an arithmetic unit (43, 38) suitable for computing physical data of motions; the measuring device is made up of a shoe unit (41) responsible for measuring the components of the force (15) emerging in the contact plane (11) between the sole (22) and the ground; the shoe unit (41) contains a transceiver unit (44) and a battery (45); whilst the central measuring device is made up of a central unit (46) apt for capturing velocity data, which is installed possibly closest to the centre of the body mass ( 17); the central unit (46) contains a central transceiver (49) and a central battery (50).

2. A device described in Claim no. 1 whereas the central arithmetic unit (48) is installed in the central unit (46).

3. A device described in Claims nos. 1 and 2 whereas the central arithmetic unit (43) is installed in the shoe unit (41).

4. A device described in Claims nos. 1 , 2 and 3 whereas the central unit (46) contains a central storage unit (47) and the shoe unit (41) contains a data storage unit (42).

5. A device described in Claims nos. 1 to 4 whereas the central unit (46) and the shoe unit (41 ) are wirelessly connected to each other.

6. A device described in Claims nos. 1 to 5 whereas at least a part of the central unit (46) is computer and/or info-communication device.

7. A method for the application of the device described in Claim no. 1 whereas with the help of the force measuring sensors (23) installed in or on the shoe (21 ) we can measure the components of force ( 15) emerging on the contact plane (1 1 ) between the sole (22) and the ground, and the central accelerometer (51 ) forming part of the central unit (46) we can measure the velocity vector (16) of the centre of mass (17) of a human body; afterwards, in the knowledge of the components of the force (15) and the velocity vector (16), the arithmetic units (43, 48) will with equation P=F * v compute the physical power output (P) of human running or walking or other motion propelled by forces exerted by the lower extremity, which then can be viewed on a display assigned to the central unit (46).

8. A method described in Claim no. 7 whereas the physical work done by a human and/or the efficiency of such work is determined with the arithmetic unit (43, 48).

9. A method described in Claims nos. 7 and 8 whereas data measured and processed are temporarily stored in the central storage unit (47) of the central unit (46) and/or in the data storage unit (42) of the shoe unit (41).

10. A method described in Claims nos. 7 to 9 whereas a tri-axial central accelerometer (51) is fastened on the user possibly closest to the plane of the centre of mass (17) of the user.