Device and method for physical training

FIELD OF THE INVENTION

The present invention relates to a device and to a method for physical training. Applications include physical training and exercise in general, for instance fitness, yoga, Pilates, weight training, body building, and aerobics.

BACKGROUND OF THE INVENTION

Recently, there has been an increased demand for correctly executing exercises that are involved in physical training. Typically, an exercise involving weight lifting is accurately performed at the beginning of the exercise, but degrades with muscle fatigue and increasing exhaustion of the athlete. Maintaining precision increases the impact of the exercise and prevents overload related injury. Accurate training is difficult to achieve, because when exercising, the athlete is concentrating on applying the force to lift the weight, rather than on accuracy.

This problem can be overcome in a number of ways, each having advantages and disadvantages.

Personal trainers can supervise the athlete when exercising, and can give recommendations. A personal trainer however is costly, and probably too expensive for most athletes, particularly for amateurs.

Fellow athletes may assist the athlete, commenting on the exercise and supervising when lifting weights. Although they are a free alternative for a personal trainer, fellow athletes may be unavailable, particularly when exercising at home.

Fitness machines comprise a frame for holding and guiding weights. The weights may be connected to cables. The athlete can select a number of the weights and lift the selected weights by pulling the cables. The machine comprises means for guiding the cables and the weights. The machine thus limits the freedom of movement of the cables, and therefore of the athlete, to avoid injuries.

However, free weights, for instance dumbbells or barbells, have renown advantages over fitness machines. The advantages include the build-up of so-called hidden muscles. Hidden muscles indicate muscles that assist the muscles of a certain muscle group

in stabilizing the movement of the weights. Muscle groups include for instance biceps, triceps, shoulders, chest, abs, traps, middle and lower back, quads, hamstrings, and calves. US-2002/0128127-A1 provides a dumbbell that is provided with a sensor, a main unit and a screen. The sensor detects the number of cycles within which a user moves the dumbbell up and down, as well as the heart beat of the user. The main unit uses the detected number of cycles and heart beat to calculate the amount of heat energy that is consumed by the user during exercising. To detect the heart beat, the user should press his thumb on a part of the sensor that is located on the hand grip of the dumbbell. Before commencing the exercise, the user should input personal data, including body height and body weight. Inputting the personal data before commencing the exercise is however time consuming, and therefore discourages the user from using the above-described functionality of the dumbbell. Also, the functionality of the known dumbbell is limited to calculating the heat energy that was consumed during the exercise.

OBJECT OF THE INVENTION

The present invention aims to provide a device and a method to maintain accurate movement during physical training.

SUMMARY OF THE INVENTION The present invention therefore provides a device for physical training, comprising: a body; sensor means that are attached to the body and are adapted to detect movement of the body between a first extreme position and a second extreme position, and to supply body movement data corresponding to the movement of the body; a data processor that is adapted to receive the body movement data from the sensor means; a data memory that is connected to the data processor; and output means that are connected to the data processor, characterized in that the data processor is adapted to: i) store template body movement data in the data memory during a time interval, the template body movement data comprising body movement data at the start of the physical training;

ii) after the time interval, compare the body movement data with the template body movement data; and iii) actuate the output means if a difference between the body movement data and the template body movement data exceeds a threshold. The device of the present invention obviates inputting user data before commencing an exercise, and the device thus is more user friendly than prior art devices. The present invention provides a relatively simple, straightforward device to assist an athlete in physical training. The device may be used combined with or included in free weights, thus providing a cost efficient, reliable and secure device for accurate exercising. The device prevents injuries by outputting for instance an alarm signal when movement of the athlete deviates more than a preset threshold from his own template movement.

In an embodiment, the data processor is adapted to repeat steps i) to iii) after actuating the output means.

In another embodiment, the time interval comprises one, two or three cycles, each cycle comprising a body movement from the first extreme position to the second extreme position and back to the first extreme position. This embodiment indicates the flexibility of the device. The template movement is recorded, irrespective of the plane of movement, i.e. irrespective whether the body is moved vertically up and down, horizontally from left to right, or diagonally. A predetermined number of cycles between the first and second extreme positions is initially stored as a template movement. If two or more cycles are included, the average movement of said cycles constructs the template movement. Continued movement is subsequently compared with the template movement. An alarm is provided when a deviation of one or more of the parameters of the body movement with the template movement exceeds a predetermined threshold. Optionally, the sensor means comprise an accelerometer. In an embodiment, the sensor means comprise a gyroscope. Optionally, the gyroscope is a three-axis gyroscope. Also, the sensor means may include a magnetometer.

In an embodiment, the body comprises a dumbbell or a waist belt. As free weights provide advantages over other means of physical training, exemplary embodiments include a dumbbell, barbell, or a waist belt.

In another embodiment, the device comprises first data transducer means that are attached to the body and are adapted to receive the body movement data from the sensor means and to send the body movement data.

In still another embodiment, the device comprises second transducer means that are connected to the data processor and are adapted to receive the body movement data that are sent by the first transducer means. The data processor and/or output means may thus be provided at a central location, external from for instance the dumbbell or barbell. The data processor and output means is thus protected from breakage when the dumbbell falls on the ground. Also, multiple dumbbells may cooperate with a single data processor and output means, thus providing a more cost efficient embodiment.

In an embodiment, the device comprises a first body and a second body, each comprising first transducer means, wherein the first transducer means of the first body and the first transducer means of the second body are adapted to exchange body movement data with each other. Thus, two or more training devices, such as dumbbells, can cooperate during the physical training. This is advantageous as many exercises involving free weights are directed to using two weights together.

The body movement data comprise for instance parameters concerning one or more of time, speed, acceleration, first extreme position, second extreme position, vertical position, horizontal position, and direction.

The threshold preferably is a difference within the range of 5-30%, for instance about 10%, 15%, 20%, or 25%. The difference concerns for instance one or more of the parameters comprised in the template body movement data. According to another aspect, the present invention provides a method for physical training, comprising the steps of: i) store template body movement data in a data memory during a time interval, the template body movement data comprising body movement data at the start of the physical training; ii) after the time interval, compare the body movement data with the template body movement data; and iii) actuate output means if a difference between the body movement data and the template body movement data exceeds a threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a dumbbell provided with an embodiment of the device according to the present invention;

Fig. 2 shows a dumbbell provided with another embodiment of the device according to the present invention;

Fig. 3 shows a person wearing a belt that is provided with the device according to the present invention;

Figs. 4 A to 4D show subsequent diagrammatic views of an exercising athlete using a dumbbell provided with the device according to the present invention; Fig. 5 shows an exemplary diagram of body movement data at the start of an exercise;

Fig. 6 shows an exemplary diagram of body movement data at the end of an exercise;

Figs. 7 A to 7D show subsequent diagrammatic views of an exercising athlete using two dumbbells provided with the device according to the present invention;

Fig. 8 shows a diagrammatic view of an embodiment of the device according to the present invention; and

Fig. 9 shows a diagrammatic view of a dumbbell provided with the device according to the present invention.

DETAILED DESCRIPTION OF EXAMPLES

In the embodiment of Fig. 1, a device for physical training according to the present invention includes a dumbbell or barbell body 10. The dumbbell body as shown comprises a handgrip 12 that is on opposite ends provided with weights 14, 16. The weight 14 is provided with sensor means, a data processor, a data memory and output means 18 that are connected to the data processor. The output means comprise for instance a display, sound generating means, and/or light generating means.

In the embodiment of Fig. 2, the device according to the present invention includes a dumbbell or barbell body 30. The dumbbell body comprises handgrip 32 that is on opposite ends provided with weights 34, 36. The weight 34 is provided with sensor means that are connected to first transducer means 40. The first transducer means are adapted to wirelessly communicate with second transducer means 42, that are connected to an external unit 44 comprising a data processor, a data memory and output means 38 that are connected to the data processor. The output means comprise for instance a display, sound generating means, and/or light generating means.

In another embodiment, shown in Fig. 3, the body of the device of the present invention includes a waist belt 50 (Fig. 3). The athlete 52 can wear the waist belt around the waist. The waist belt 52 is provided with a main unit 54 comprising sensor means, a data processor, a data memory and output means 58 that are connected to the data processor.

The device for physical training of the present invention can for instance be used in single mode (Fig. 4), or in dual mode (Fig. 7).

In single mode, the user is required to adopt an initial or starting position (Fig. 4A). The user must subsequently perform a predetermined number of cycles, for instance one, two, three or more cycles. One cycle consists of moving the dumbbell 10 from a first extreme position to a second extreme position and back to the first extreme position. The first extreme position is the starting position shown in Fig. 4A. The second extreme position is for instance the position shown in Fig. 4B. The dumbbell movement during the initial, predetermined number of cycles is recorded and stored as a template movement. If the predetermined number of cycles comprises two or more cycles, the template movement is for instance the average movement of the predetermined number of cycles. The template movement is used to validate all further repetitions, as illustrated in Figs. 4C and 4D. If the difference of the movement of the dumbbell 10 and the template movement exceeds a predetermined threshold, as shown in Fig. 4D, the output means will produce an alarm, for instance a sound and/or a light signal.

An exemplary recording of the beginning of a dumbbell raising exercise is shown in Fig. 5, wherein the x-axis indicated time t in seconds, and the y-axis indicates height h in meters. The initial three cycles are performed accurately. Vertical lines having the open circles at the end indicate the minimum height (first extreme position) and the maximum height (second extreme position).

The accuracy of the exercise typically degrades significantly during the exercise, as indicated in Fig. 6. Fig. 6 shows an example of the final three repetitions of the dumbbell raising exercise of Fig. 5, wherein again minimum height and maximum height are indicated by vertical straight lines. The dumbbell movement data of Fig. 6 can be used in a number of ways to extract parameters to determine deviations from the template movement. For instance, the time in between the first and second extreme position may be calculated, and be used as a parameter. Further parameters are for instance acceleration of the dumbbell, indicating jerk or jitter, or the ability to maintain posture and hold the dumbbell at the first or the second extreme position. The deterioration of the latter is clear upon comparing the cycles of fig. 6 and fig. 5. Also, in the cycles of fig. 6, the dumbbell is lowered much faster than during the cycles shown in fig. 5. Further parameters are speed, first extreme position, second extreme position, vertical position, horizontal position, and direction.

Algorithms used by the data processing unit may include an algorithm to determine the minimum and the maximum of a certain parameter. Also, the data processor may compare the actual path of movement, by using for instance a time warping algorithm.

In dual mode, as a calibration step, the athlete adopts a starting position carrying two dumbbells 10, as shown in Fig. 7A. The athlete subsequently starts the exercise, for instance raising the two dumbbells from the first extreme position shown in Fig. 7A to the second extreme position shown in Fig. 7B. The data processor records the initial cycles and stores a template movement, as described above in relation to the single mode.

The two dumbbells 10 may exchange movement data, indicated by the arrow between the two dumbbells. Dumbbell movement data is either transmitted from one dumbbell to the other, or both dumbbells 10 transmit their respective movement data to the other dumbbell. The processing unit compares the two streams of dumbbell movement data with the template movement data. If one or more parameters of the dumbbell movement data of one or both dumbbells deviate more than a predetermined threshold from the corresponding parameters of the template movement data, the data processor actuates the output means to generate an alarm signal, as indicated in Fig. 7D.

In practice, the threshold may be a fixed percentage. The threshold may be a difference within the range of 5-30%, for instance about 10%, 15%, 20%, or 25%.

The threshold may also include more than one percentage. For example, instead of allowing a 15% deviation of the movement through the whole cycle, the threshold may be a 5% deviation at the first and second extreme positions, whereas in between the extreme positions, the threshold may allow 20% deviation from the template movement. The lower threshold percentage at the extreme positions ensures accurate start and stop positions.

For instance, the template movement may provide the time t0 of the first extreme position and the time t3 of the second extreme positions. Time tl and time t2 represent certain points in time between t0 and t3. The following expression may than provide a code to implement a flexible threshold:

Threshold = {(tθ, tl, 5%), (tl, t2, 20%), (t2, t3, 5%)}

In another example, a flexible threshold may use percentages of a full cycle. For instance, t0 represents the time at the beginning of the cycle, and t3 represents the time of a full cycle. Than, tl is for instance the time after 10% of t3, and t2 is 90% of t3.

In still another example, the reference template may be fixed, whereas the threshold may be dynamic over time. For example, the threshold may differ per session.

In a practical embodiment (Fig. 8), the device 100 of the present invention includes a data processing and data storage unit 102. The data processing unit 102 stores reference or template patterns, and compares dumbbell movement with a currently stored template pattern. The data processing unit 102 may be connected to sensor means 104, which are elucidated below. Optionally, the data processing unit 102 is connected to input/output unit 106. The input/output unit 106 for instance enables the athlete to indicate the start or end of an exercise, or of the template recording. The input/output unit 106 therefore may include buttons, motion detection, voice detection, and/or a counter. Also, the input/output device 106 may include the output means, including for instance one or more lights, a display, and/or a speaker. Voice recordings may be stored in the data storage part of the processing unit 102, which can be used to instruct or motivate the athlete during the exercise.

In for instance the embodiments shown in Figs. 2 and 7, the device include a radio or transducer unit 108 that is connected to the data processing unit 102. The transducer means of the radio unit 108 may comprise wifϊ equipment according to an international standard such as IEEE 802.11.

In practice, the sensor means comprise for instance a three- dimensional magnetometer, a three-dimensional accelerometer and/or a gyroscope. If the sensor means comprise a magnetometer, the (dumbbell) body is constructed of a nonmagnetic metal and/or a plastic. Three-dimensional movement, as shown in Fig. 9, may thus be recorded. Three-dimensional movement includes horizontal movement along the x-axis and the z-axis, and vertical movement along the z-axis. Position 1 indicates the first extreme position, and position 2 indicates the second extreme position. During the exercise, the dumbbell is moved from position 1 to position 2 and back.

The gyroscope may for instance include a solid state angular rate gyroscope ARS-C 122- IA, ARS-C 132- IA, or ARS-C 142- IA, as provide by Watson Industries, Inc. Such gyroscopes are robust, low cost, low weight, are suitable to indicate movement along multiple - for example three - axis, and are devoid of moving parts to improve durability and reduce wear.

The device of the present invention assists the user in accurately training using free weights. Thus, the advantages of free weighs are combined with the advantages of accurate training. The athlete will achieve better results, or achieve goals faster. Thus, the

device of the present invention assists in motivating the athlete, encouraging the athlete to continue training.

The present invention is not limited to the embodiments described above, wherein many modifications are conceivable within the scope of the appended claims. Features of embodiments may be combined. The body may for instance include a barbell, dumbbell, waist belt, arm belt, or any other means suitable for physical training.