WO2009074942A1

WO2009074942A1 - System and method for monitoring the execution of a pulley-based exercise

Info

Publication number: WO2009074942A1
Application number: PCT/IB2008/055139
Authority: WO
Inventors: Gerd Lanfermann; Kai Eck; Olaf Such
Original assignee: Koninklijke Philips Electronics N.V.; Philips Intellectual Property & Standards Gmbh
Priority date: 2007-12-13
Filing date: 2008-12-08
Publication date: 2009-06-18

Abstract

The present invention relates to pulley-based fitness or rehabilitation exercise systems. More specifically, the present invention relates to a system for monitoring the execution of a pulley-based exercise, comprising an exercise template database (1), a feedback module (2), a calculating module (3) and a tracking module (4). The tracking module (4) determines the spatial position of a handle of a pulley. The calculating module (3) compares the spatial position of the handle of a pulley with a corresponding exercise template. The feedback module (2) provides information based on the result of the comparison in the calculating module (3). The present invention furthermore relates to a method for monitoring the execution of a pulley-based exercise and to an exercise device comprising a pulley and a system according to the invention.

Description

System and method for monitoring the execution of a pulley-based exercise

BACKGROUND OF THE INVENTION

The present invention relates to pulley-based fitness or rehabilitation exercise systems. More specifically, the present invention relates to a system for monitoring the execution of a pulley-based exercise, comprising an exercise template database, a feedback module, a calculating module and a tracking module. The present invention furthermore relates to a method for monitoring the execution of a pulley-based exercise and to an exercise device comprising a pulley and a system according to the invention.

There is an increasing trend in modern fitness and rehabilitation operations towards functional exercises consisting of motions that closely resemble the tasks of daily living. This is quite a significant shift from previously known fitness machines which allowed a very limited degree of freedom while, for example, performing a bench press. Functional exercises have the advantage that they contribute more efficiently to a core strength, flexibility and stability in daily life.

Pulleys are a commonly used device to perform these exercises in a controlled machine environment. These pulleys operate by means of a cable which is wound up under tension and which generates a resistive force as it is being pulled by the user. Their key advantage over the traditional fitness machines is the fact that they allow for free movements while exerting sufficient resistance in order to train the muscles. One of the most modern systems consists of a dual cable system: two cable pods are used to store the wound cables at the top and the bottom of the pulley frame.

The problem with these types of exercising system lies in the fact that a user can easily perform exercises wrongly. Then an instructor needs to correct the user's posture. This especially applies when there are more than one exercise to be performed with the pulley. With respect to aiding a user in performing exercises, US 4,828,257 discloses a system and method for providing an exercise program at a desired pace throughout each repetition and which applies resistance against a user's efforts based upon user performance history and user demographics. A central controller stores user demographics and performance information, and provides this information as well as program criteria and evaluations to any of a plurality of exercise stations. The exercise stations each include a magnetic brake for producing the desired resistance levels. A central processor unit (CPU) controls the exercise program at each station. The initial brake resistance is established based upon user demographic information and initial user performance of an exercise. The brake resistance is represented by lights in an LED stack simulating weights which move up and down along a run in conformity with position of a movement arm which the user moves. A pacer light moving adjacent the LED weight stack guides the user at a desired pace throughout each repetition.

User performance including rate and limb extension is monitored and resistance is changed during the exercise period as performance corresponds to selected criteria. The user's performance is evaluated based on performance history and demographically-based criteria to provide coaching comments to the user and to propose changes to the exercise program. Selected educational and instructional material relevant to the particular user may also be provided. In addition, by monitoring user parameters such as weight and percent body fat, and in view of user demographic and performance information, diet control information may also be provided. User performance during the exercise period is visually depicted by a group of light bars which simulate weights moving up and down in conventional weight-pulley equipment. In summary, a complex system is used to simulate a pulley exercise. Despite this effort there still exists the need for a less complicated system and method capable of assisting persons when performing a variety of exercises with pulley equipment.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed towards a system for monitoring the execution of a pulley-based exercise, comprising an exercise template database, a feedback module, a calculating module and a tracking module; wherein the calculating module is in communication with the exercise template database, the tracking module and the feedback module; wherein the exercise template database comprises data representing the spatial position of a handle of a pulley which is being used during an exercise; wherein the tracking module determines the spatial position of a handle of a pulley which is being used during an exercise; wherein the calculating module compares the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template; and wherein the feedback module provides information based on the result of the comparison in the calculating module.

The present invention is further directed towards a method for monitoring the execution of a pulley-based exercise, comprising the steps of: a) providing a system according to the present invention; b) accessing an exercise template from an exercise template database; c) determining the spatial position of a handle of a pulley which is being used during an exercise; d) comparing the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template; and e) providing feedback based on the result of the comparison. The present invention furthermore encompasses an exercise device, comprising a pulley and a system according to the present invention.

In summary, the present invention allows for a correction of pulley-based exercises by assessing and comparing the movements of the pulley handle with a movement template and by informing the exercising person if the movement deviates from the template. Thus, the usefulness of a pulley which is a mechanically simple exercise device is increased. Furthermore, a fitness trainer or physical therapist is relieved of routine monitoring tasks and can concentrate on persons more needing of attention. This has a direct impact on the economic performance of a gymnasium or rehabilitation practice.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a modular diagram of a system according to the present invention

Fig. 2 shows the course of a typical pulley-based exercise

Fig. 3 shows a flow chart of a method according to the present invention

DETAILED DESCRIPTION OF THE INVENTION

Before the invention is described in detail, it is to be understood that this invention is not limited to the particular component parts of the devices described or process steps of the methods described as such devices and methods may vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an" and "the" include singular and/or plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a handle" includes two or more such devices and the like. Referring now to Fig. 1 , a modular diagram of a system for monitoring the execution of a pulley-based exercise according to the present invention is shown. Pulley- based exercises are to be understood as exercises comprising the use of a pulley where a retractable member such as a cord or a wire can be extracted by overcoming a mechanical force. Furthermore, pulley-based exercises in the context of the present invention also extend to exercises where an elastic material is elongated which then provides the mechanical force. Suitable elastic materials may be natural or synthetic rubber. Pulley-based exercises may also be embodied by training machines which simulate the rowing of a boat. These machines are also simply known as rowing machines. The system comprises an exercise template database 1, a feedback module 2, a calculating module 3 and a tracking module 4 which are in communication with each other; the calculating module 3 being the hub. The communication may take place via wired means, optical means such as infrared communication or via wireless techniques such as the IEEE 802.11 protocol or the Bluetooth protocol.

The exercise template database 1 comprises data representing the spatial position of a handle of a pulley which is being used during an exercise. In general, a handle of a pulley is to be understood in a broad sense as being the part of the pulley system that is contacted by the person performing the exercise. This may include a handle, handles or a handlebar that are grasped by the hands, attached to the feet, strapped to the thighs, chest, or the like. In general, the handle of the pulley will be at the end of the retractable member such as the cord or wire of the pulley. It is advantageous to focus on the handle as this is the part of the machinery that is usually closest to the person and the muscle groups involved in the exercise. Suitable data formats for the spatial position include three-dimensional Cartesian coordinates or polar coordinates with a distance r, angles θ and Φ. It is possible for the database to comprise representations of more than one specific exercise. While the entire motion path may be stored as an exercise template, in simple cases the starting and the end point of a pulley handle movement may be sufficient to describe an exercise.

The tracking module 4 determines the spatial position of a handle of a pulley which is being used during an exercise. It is advantageous that the positional data format corresponds to the data format in the exercise template database 1. Again, suitable data formats for the spatial position include three-dimensional Cartesian coordinates or polar coordinates with a distance r, angles θ and Φ. It is possible that the tracking module 4 tracks one or more than one positions simultaneously. Furthermore, the position of the handle may be tracked by determining the position of the limb that is grasping the handle during the exercise. For example, the position of a hand or of the hands may be tracked and the position of the handle inferred from this information. In general, the system according to the present invention is independent of the representation as spatial absolute position data or as relative angular information.

The calculating module 3 compares the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template. The data is supplied from the tracking module 4 and the exercise template database 1 , respectively. The calculating module 3 may, for example, be an embedded and specifically instructed microprocessor or be in the form of a general purpose microcomputer in combination with the appropriate software. It is possible that the calculating module 3 performs more than one comparison simultaneously. The comparison may be in the form of a subtraction. Furthermore, the result of the comparison may trigger an action if a predetermined threshold is violated. By way of example, an action may be triggered if the handle is moved too slowly, too rapidly or if the motion path is not followed.

The feedback module 2 provides information based on the result of the comparison in the calculating module 3. Information may be in the form of optical, acoustical, vibrational messages or the like. The person performing the exercise may be informed that the motion path of the handle and thus the execution of the exercise is incorrect, too slow or too fast. Furthermore, the person may be informed if the range of motion according to the exercise has been exceeded. The feedback module may be a display screen where the exercise is represented in the form of avatars. Another option is to play recorded speech messages to the person performing the exercise, for example in the form of "too slow", "too fast", "handle is too low" or "handle is too high". A further form of feedback is written feedback to document the course of the exercise.

In one embodiment of the present invention the tracking module 4 determines the spatial position of the handle via motion sensors, optical tracking and/or electromagnetic emission. This can be classified as a direct monitoring of the handle and thus of the pulley cable end points. In the case where the sensors, optical marks or electromagnetic emitters supply the system with relative angular information, it is also advantageous to provide a data set of the limb length of the individual person. This is in order to transform angular information into spatial position data. Suitable limbs to be included in the data set may be the length of the upper arm, the lower arm, the thigh, the lower leg and the torso. This data may be stored in the exercise template database 1 so that it can be accessed by the tracking calculating module 3.

Motion sensors can be gyroscopes, acceleration sensors, magnetic sensors, gravity sensors or integrated combinations thereof. Highly integrated solid-state motion sensors are commercially available. They may also be referred to as inertial sensors. It is possible to integrate the sensors into the handle of the pulley. Alternatively, the sensor may be worn on the hand, foot or other limb of the person in contact with the handle. It is possible to use data from the sensor to calculate the orientation of the handle with respect to the pulley frame of reference. Furthermore, the person performing the exercise may wear additional sensors. This has the advantage that the orientation of the handle may be calculated relative to the person. Thus, the user is not restricted to a certain location when performing the exercise. The user may operate more freely.

Optical tracking can be undertaken by two or more cameras viewing the end point of the pulley cable and thus the handle. The cameras are positioned to view the handle at different angles. Specially marked end points may be monitored by the cameras. An example for such a marking is color or infrared resistive marking. Two or more markers may be used. This has the advantage that additional information on the orientation of the handle in space may be gathered. It is possible for the camera system to track the position and/or orientation of more than one handle.

Tracking via electromagnetic emission involves a sender or emitter which transmits electromagnetic radiation such as radio frequency radiation. The signal is received by receptors which are located at appropriate positions such as the frame of the pulley. The receptors analyze the emitted signal and construct the location and orientation of the sender and thus of the handle or cable end point.

In another embodiment of the present invention the tracking module 4 determines the spatial position of the handle by calculating the length of a cable that has been extracted from a cable pod of the pulley and the direction of the cable as it leaves the cable pod. This can be classified as an indirect monitoring of the handle and thus of the pulley cable end points because the cable length and the cable direction represent a vector to the cable end point.

The direction of the cable as it leaves the cable pod may be expressed in terms of the polar coordinate angles θ and Φ. One way of determining these angles is to connect the cable pod to a support structure via a cardan joint. Then the horizontal and vertical movements can be detected. Another possibility is to place a cardan joint at the exit of the cable from the cable pod. Furthermore, a camera system evaluating the projection of the cable onto the xy-, xz- and yz-plane of a cartesian coordinate system may also determine the direction of the cable. It is possible to determine the length of a cable that has been extracted from a cable pod of the pulley by a camera system which detects markings on the cable or on the cable reel. After detection the markings are counted and correlated with the amount of cable that has left the pod. If the number of rotations of the cable reel are counted, a correction factor needs to account for the fact that the circumference of the cable reel as defined by the wound-up cable changes when the cable is extracted.

It is also possible to determine the cable length by a camera system which evaluates the horizontal and vertical projection of the cable leaving the cable pod. The projection of the cable in its spatial orientation onto perpendicular planes results in data which can be used by trigonometrical calculations to give the length of the cable. Another option is to determine the cable length by a mechanical system which determines the restoring force exerted onto the cable. This is possible in pulley designs where the force needed to extract the cable is proportional to the extracted cable length.

In another embodiment of the present invention the spatial position of a handle of a pulley in the exercise template database is stored in a time-resolved manner and the tracking module determines the spatial position of a handle of a pulley in a time-resolved manner. Time-resolved spatial positions provide for that the speed of the handle is represented. Thus, a further dimension is introduced into the polar or cartesian coordinate data sets. A suitable resolution can be a position data set every 1, 10 or 50 milliseconds. In general, including a temporal resolution in describing or tracking the pulley handle position allows for the dynamics of the movement to be assessed and used for the correction of an exercise.

In another embodiment of the present invention the data stored in the exercise template database 1 comprises information representing the spatial position of the handle of a pulley at the start and the end of an exercise and/or the acceleration of the handle of a pulley. The starting and end points are important because this determines which muscle groups are used and how a joint is exercised. Incorrect positions may lead to injuries. Furthermore, a person exercising is prevented from cheating. The acceleration may guide in performing an isokinetic exercise correctly. Also, injuries due to excessive acceleration can be prevented. In another embodiment of the present invention the comparison performed in the calculating module 3 addresses the deviation of the actual from the template starting and end point, the smoothness of the exercise and/or the dynamic profile of the movement. The importance of the starting and end points has already been discussed. With respect to the smoothness of the exercise, this parameter reflects the variation of the acceleration of the handle. A low smoothness, corresponding to a jerky action, may indicate a mechanical problem of the system. It may also indicate too much resistive force so the person performing the exercise is overexerting himself. The dynamic profile of the movement can be formed by the first and second derivatives of the position of the handle with respect to the time. For example, if an exercise requires the person to pull the handle slowly and then hold this position, the dynamic profile would be a constant and low speed followed by a speed of zero for a specified time.

In another embodiment of the present invention the exercises represented in the exercise template database 1 can be modified and the modifications can be assigned to individual persons. In other words, the templates can be personalized for individual exercisers. The customization may modify the template to reflect the height of the person, the strength of the person or the progress of the person in exercise training or rehabilitation. All this serves to more effectively use the pulley equipment. The customizations may be entered manually or automatically according to the progress of the person. It is possible that the system further comprises an identification system for identifying individual persons. Also it is possible that the individually modified exercise template can be accessed and used when comparing the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template. Suitable identification systems may be based on radio frequency identification (RFID) tags. Other systems may be in the form of chip cards or bar codes which could be worn on bracelets. By way of example, a person with a personal identification RFID tag would grasp the handle at the start of an exercise. His personal information is read and passed on to the exercise template database where a customized exercise template is accessed. The person performs the exercise. His performance is registered and used to modify the personal template according to his progress. The next time he performs the exercise at this pulley system, the updated exercise template is used.

Referring now to Fig. 2, the course of a typical pulley-based exercise is depicted. A cable pod 5 is in a stationary position and provides cable 6. Handle 7 is affixed to the end of cable 6. At the start of the exercise, handle 7 is in a starting position indicated by arrow 8. In a first set of repetitions, the exercise is performed incorrectly. The handle 7 is moved between the starting position 8 and an incorrect position indicated by arrow 9. The trajectories of the handle 7 are represented by the trajectory bundle 10. In a second set of repetitions, the exercise is performed correctly. Handle 7 is moved from starting position 8 to end position 9'. This end position is also visualized by cable 6' and handle T. The trajectories of the handle 7 are also represented by the trajectory bundle 10'. It should be noted that the cable 6' in the end point of the correct exercise is longer that the cable 6 when the pulley is in its starting position. It should also be noted that the trajectories 10 in the incorrect exercise are, on average, much rougher or jerkier than the trajectories 10'. Referring now to Fig. 3, a flow chart of a method for monitoring the execution of a pulley-based exercise is shown. The method as depicted firstly calls for providing a system according to the present invention in step 20. Step 21 concerns accessing an exercise template from an exercise template database. Step 22 concerns determining the spatial position of a handle of a pulley which is being used during an exercise. Step 23 concerns comparing the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template. Step 24 concerns providing feedback based on the result of the comparison. In the method according to the present invention, it is possible that the spatial position of the handle is determined in a time- resolved manner. A suitable temporal resolution may be every 1, 10 or 50 milliseconds. With respect to the individual steps of the method, reference is made to the description of the system according to the present invention.

To provide a comprehensive disclosure without unduly lengthening the specification, the applicant hereby incorporates by reference each of the patents and patent applications referenced above. The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed.

Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention's scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.

Claims

CLAIMS:

1. A system for monitoring the execution of a pulley-based exercise, comprising an exercise template database (1), a feedback module (2), a calculating module (3) and a tracking module (4); wherein the calculating module (3) is in communication with the exercise template database (1), the tracking module (4) and the feedback module (2); wherein the exercise template database (1) comprises data representing the spatial position of a handle of a pulley which is being used during an exercise; wherein the tracking module (4) determines the spatial position of a handle of a pulley which is being used during an exercise; wherein the calculating module (3) compares the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template; and wherein the feedback module (2) provides information based on the result of the comparison in the calculating module.

2. System according to claim 1, wherein the tracking module (4) determines the spatial position of the handle via motion sensors, optical tracking and/or electromagnetic emission.

3. System according to claim 1, wherein the tracking module (4) determines the spatial position of the handle by calculating the length of a cable that has been extracted from a cable pod of the pulley and the direction of the cable as it leaves the cable pod.

4. System according to claim 1 , wherein the spatial position of a handle of a pulley in the exercise template database (1) is stored in a time-resolved manner and wherein the tracking module (4) determines the spatial position of a handle of a pulley in a time- resolved manner.

5. System according to claim 1, wherein the data stored in the exercise template database (1) comprises information representing the spatial position of the handle of a pulley at the start and the end of an exercise and/or the acceleration of the handle of a pulley.

6. System according to claim 1, wherein the comparison performed in the calculating module (3) addresses the deviation of the actual from the template starting and end point, the smoothness of the exercise and/or the dynamic profile of the movement.

7. System according to claim 1, wherein the exercises represented in the exercise template database (1) can be modified and wherein the modifications can be assigned to individual persons.

8. System according to claim 7, further comprising an identification system for identifying individual persons and wherein the individually modified exercise template is accessed and used when comparing the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template.

9. Method for monitoring the execution of a pulley-based exercise, comprising the steps of: a) providing a system according to claim 1 ; b) accessing an exercise template from an exercise template database; c) determining the spatial position of a handle of a pulley which is being used during an exercise; d) comparing the spatial position of the handle of a pulley during an exercise with the spatial position of a handle of a pulley in a corresponding exercise template; and e) providing feedback based on the result of the comparison.

10. Exercise device, comprising a pulley and a system according to claim 1.