METHOD AND SYSTEM FOR DETERMINING EXISTENCE OF MAGNETIC DISTURBANCES

Abstract

A method for adjusting operation of a motion tracking system having a computing device and sensors, wherein each sensor includes a magnetometer, a gyroscope and an accelerometer, includes the following steps: receiving, the computing device, a magnetic field measurement from each of the sensors; digitally processing, the computing device, each of the magnetic field measurements in order to determine if a difference of intensities and/or inclinations of at least one pair of magnetic field measurements exceeds a threshold value, and/or if an x,y point with the differences of intensities and inclinations as coordinates thereof falls outside of a threshold area; and adjusting the operation of the motion tracking system if at least one difference exceeds the threshold value and/or the x,y point falls outside of the threshold area.

Claims

1. A method for adjusting operation of a motion tracking system for tracking motion of a person and comprising a computing device and a plurality of sensors, each sensor comprising a magnetometer, a gyroscope and an accelerometer, the method including the following steps: receiving, by the computing device, a magnetic field measurement from each sensor of the plurality of sensors; digitally processing, by the computing device, each of the magnetic field measurements in order to determine at least one of: if a difference of at least one of intensities and inclinations of at least one pair of magnetic field measurements exceeds a threshold value, and if an x,y point with the differences of intensities and inclinations as coordinates thereof falls outside of a threshold area; and adjusting the operation of the motion tracking system if at least one of: at least one difference exceeds the threshold value and the x,y point falls outside of the threshold area.

2. The method of claim 1, wherein the step of adjusting the operation of the motion tracking system comprises at least one of: not processing the magnetic field measurements in a sensor fusion algorithm of respective sensors, the respective sensors being those for which the computing device has determined that at least one of: the difference of at least one of intensities and inclinations exceeds the threshold value, and the x,y point falls outside of the threshold area; digitally adjusting one of a motion tracking procedure or a physical exercise evaluation procedure; and providing at least one user perceptible signal indicative of the computing device having determined that at least one magnetic field measurement is anomalous.

3. The method of claim 2, wherein the step of adjusting the operation of the motion tracking system at least comprises digitally adjusting a physical exercise evaluation procedure; and wherein digitally adjusting the physical exercise evaluation procedure comprises digitally adjusting an algorithm with which the motion tracking system digitally determines whether a user tracked with the plurality of sensors performs a physical exercise.

4. The method of claim 1, wherein the step of digitally processing each of the magnetic field measurements comprises determining, for each pair of magnetic field measurements: whether a difference of intensities of the magnetic field measurements exceeds an intensity threshold; whether a difference of inclinations of the magnetic field measurements exceeds an inclination threshold; and whether a weighted sum of the difference of intensities and the difference of inclinations exceeds a combined threshold; wherein the operation of the motion tracking system is adjusted if at least one of: at least one of the differences of intensities exceeds the intensity threshold, at least one of the differences of inclinations exceeds the inclination threshold, and at least one of the weighted sums exceeds the combined threshold.

5. The method of claim 1, wherein the step of receiving the magnetic field measurement from each sensor of the plurality of sensors includes the following steps: receiving, by the computing device, a plurality of magnetic field measurements from each sensor of the plurality of sensors; and digitally selecting, by the computing device, one magnetic field measurement from each plurality of magnetic field measurements provided by the sensors such that a time difference between each pair of selected magnetic field measurements is as short as possible.

6. The method of claim 1, further comprising measuring, each sensor of the plurality of sensors, a magnetic field, thereby providing the respective magnetic field measurement, while the sensors are at least one of: provided on a target tracked with the plurality of sensors; and introduced in a holding device, the holding device comprising at least one cavity adapted for introduction of one or more sensors of the plurality of sensors, the motion tracking system comprising the holding device.

7. The method of claim 1, wherein: each sensor of the plurality of sensors provides the magnetic field measurements decomposed into intensity and inclination of the measured magnetic field; or the computing device decomposes each magnetic field measurement into intensity and inclination of the measured magnetic field.

8. A motion tracking system for tracking motion of a person, comprising: a computing device comprising at least one processor and at least one memory; and a plurality of sensors, each sensor comprising a magnetometer, a gyroscope and an accelerometer, and each sensor being configured to provide a magnetic field measurement; the at least one processor is configured, together with the at least one memory, to digitally process the magnetic field measurement of each sensor of the plurality of sensors in order to determine at least one of: if a difference of at least one of intensities and inclinations of at least one pair of magnetic field measurements exceeds a threshold value, and if an x,y point with the differences of intensities and inclinations as coordinates thereof falls outside of a threshold area; and the at least one processor is further configured, together with the at least one memory, to adjust operation of the motion tracking system if at least one of: at least one difference exceeds the threshold value and the x,y point falls outside of the threshold area.

9. The motion tracking system of claim 8, wherein the at least one processor is configured, together with the at least one memory, to adjust the operation of the motion tracking system by at least one of: not processing the magnetic field measurements in a sensor fusion algorithm of respective sensors, the respective sensors being those for which the at least one processor has determined that at least one of: the difference of at least one of intensities and inclinations exceeds the threshold value, and the x,y point falls outside of the threshold area; digitally adjusting one of a motion tracking procedure or a physical exercise evaluation procedure, the motion tracking procedure or the physical exercise evaluation procedure being run in the at least one processor; and providing at least one user perceptible signal indicative of the at least one processor having determined that at least one magnetic field measurement is anomalous, the motion tracking system comprising at least one means for providing the at least one user perceptible signal.

10. The motion tracking system of claim 9, wherein the at least one processor adjusts the operation of the motion tracking system at least by digitally adjusting the physical exercise evaluation procedure, and wherein digitally adjusting the physical exercise evaluation procedure comprises digitally adjusting an algorithm with which the motion tracking system digitally determines whether a user tracked with the plurality of sensors performs a physical exercise.

11. The motion tracking system of claim 8, wherein the at least one processor digitally processes the magnetic field measurement of each sensor of the plurality of sensors for determining, for each pair of magnetic field measurements: whether a difference of intensities of the magnetic field measurements exceeds an intensity threshold; whether a difference of inclinations of the magnetic field measurements exceeds an inclination threshold; and whether a weighted sum of the difference of intensities and the difference of inclinations exceeds a combined threshold; wherein the at least one processor adjusts the operation of the motion tracking system if at least one of: at least one of the differences of intensities exceeds the intensity threshold, at least one of the differences of inclinations exceeds the inclination threshold, and at least one of the weighted sums exceeds the combined threshold.

12. The motion tracking system of claim 8, wherein the at least one processor is further configured, together with the at least one memory, to digitally select one magnetic field measurement from each plurality of magnetic field measurements provided by the sensors such that a time difference between each pair of selected magnetic field measurements is as short as possible.

13. The motion tracking system of claim 8, wherein at least one of: each sensor of the plurality of sensors is configured to measure a magnetic field, thereby providing the respective magnetic field measurement, while the sensor is provided on a target tracked with the plurality of sensors; and the motion tracking system further comprises a holding device, the holding device comprising at least one cavity adapted for introduction of one or more sensors of the plurality of sensors, and each sensor of the plurality of sensors is configured to measure a magnetic field, thereby providing the respective magnetic field measurement, while the sensor is introduced in the holding device.

14. The motion tracking system of claim 8, wherein: the at least one processor is further configured, together with the at least one memory, to decompose each magnetic field measurement provided by the sensors into intensity and inclination of the measured magnetic field; or each sensor of the plurality of sensors is configured to provide the magnetic field measurement decomposed into intensity and inclination of the measured magnetic field.

15. (canceled)

16. A computer-readable storage medium having stored therein a computer program product that, when executed by a computing device, cause the computing device to perform: receiving a magnetic field measurement from each sensor of a plurality of sensors of a motion tracking system for tracking motion of a person; digitally processing each of the magnetic field measurements in order to determine at least one of: if a difference of at least one of intensities and inclinations of at least one pair of magnetic field measurements exceeds a threshold value, and if an x,y point with the differences of intensities and inclinations as coordinates thereof falls outside of a threshold area; and adjusting the operation of the motion tracking system if at least one of: at least one difference exceeds the threshold value and the x,y point falls outside of the threshold area.

17. The computer-readable storage medium of claim 16, wherein adjusting the operation of the motion tracking system comprises at least one of: not processing the magnetic field measurements in a sensor fusion algorithm of respective sensors, the respective sensors being those for which the computing device has determined that at least one of: the difference of at least one of intensities and inclinations exceeds the threshold value, and the x,y point falls outside of the threshold area; digitally adjusting one of a motion tracking procedure or a physical exercise evaluation procedure; and providing at least one user perceptible signal indicative of the computing device having determined that at least one magnetic field measurement is anomalous.

18. The computer-readable storage medium of claim 17, wherein digitally adjusting the physical exercise evaluation procedure comprises digitally adjusting an algorithm with which the motion tracking system digitally determines whether a user tracked with the plurality of sensors performs a physical exercise.

19. The computer-readable storage medium of claim 16, wherein digitally processing each of the magnetic field measurements comprises determining, for each pair of magnetic field measurements: whether a difference of intensities of the magnetic field measurements exceeds an intensity threshold; whether a difference of inclinations of the magnetic field measurements exceeds an inclination threshold; and whether a weighted sum of the difference of intensities and the difference of inclinations exceeds a combined threshold; wherein the operation of the motion tracking system is adjusted if at least one of: at least one of the differences of intensities exceeds the intensity threshold, at least one of the differences of inclinations exceeds the inclination threshold, and at least one of the weighted sums exceeds the combined threshold.

20. The computer-readable storage medium of claim 16, wherein receiving the magnetic field measurement from each sensor of the plurality of sensors comprises: receiving a plurality of magnetic field measurements from each sensor of the plurality of sensors; and digitally selecting one magnetic field measurement from each plurality of magnetic field measurements provided by the sensors such that a time difference between each pair of selected magnetic field measurements is as short as possible.

21. The computer-readable storage medium of claim 16, wherein the computer program product further causes the computing device to perform: receiving, from each sensor of the plurality of sensors, a magnetic field, thereby receiving the respective magnetic field measurement, while the sensors are at least one of: provided on a target tracked with the plurality of sensors; and introduced in a holding device, the holding device comprising at least one cavity adapted for introduction of one or more sensors of the plurality of sensors, the motion tracking system comprising the holding device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate embodiments of the invention, which should not be interpreted as restricting the scope of the invention, but just as examples of how the invention can be carried out. The drawings comprise the following figures:

[0076] FIG. 1 diagrammatically shows a motion tracking system in accordance with an embodiment.

[0077] FIG. 2 diagrammatically shows a method in accordance with an embodiment.

[0078] FIGS. 3A-3B show a holding device of a motion tracking system in accordance with an embodiment.

[0079] FIGS. 4-5 show graphs with threshold values and threshold areas.

DESCRIPTION OF WAYS OF CARRYING OUT THE INVENTION

[0080] FIG. 1 diagrammatically shows a motion tracking system 10 in accordance with an embodiment. The motion tracking system 10 includes a plurality of sensors 21-24 and a computing device 40.

[0081] The sensors 21-24 are MARG sensors that include a magnetometer 31, a gyroscope 32 and an accelerometer 33. The sensors 21-24 also include at least one processor 36 and at least one memory 37 for running a sensor fusion algorithm. In preferred embodiments such as the one of FIG. 1, the sensors 21-24 further include a first communications module 38 for transmitting and receiving data that enables the sensors 21-24 to transmit (through a wired or wireless communications technology and protocol known by a skilled person, for instance but without limitation, Bluetooth communications, cellular network communications such as GSM, UMTS or LTE, wireless LAN communications, etc.) measurements of each of the sensing devices 31-33 and/or measurements as provided by the sensor fusion algorithm to the computing device 40. The same first communications modules 38 enable the sensors 21-24 to receive data from the computing device 40. In less preferred embodiments, the sensors 21-24 are not provided with the first communications module 38; in these embodiments, data can be extracted from the sensors 21-24 and/or provided to the sensors 21-24 by means of a computer readable storage medium.

[0082] The sensors 21-24 may be adapted for arrangement on the target with attaching means that the sensors 21-24 comprise or be held on the target (e.g. a person) whose motion is to be tracked with attaching means that the target comprise. The attaching means may be e.g. straps, mechanical clips, Velcro, etc.

[0083] The computing device 40 includes at least one processor 42 and at least one memory 44. Preferably, the computing device 40 further includes a second communications module 46 for transmitting and receiving data. When the computing device 40 is not provided with the second communications module 46, data can be extracted therefrom and/or introduced therein by means of a computer readable storage medium.

[0084] FIG. 2 diagrammatically shows a method 100 in accordance with an embodiment.

[0085] The method 100 comprises a step of receiving 101, a computing device (for example the computing device 40 of FIG. 1) of a motion tracking system (for example the motion tracking system 10 of FIG. 1), a magnetic field measurement from each sensor of a plurality of sensors (for example the sensors 21-24 of FIG. 1) of the motion tracking system. Each sensor measures the magnetic field, preferably a number of times, so as to provide the magnetic field measurements to the computing device. Preferably, the sensors measure the magnetic field while the same are introduced in a holding device (for example the holding device 50, which is described below with reference to FIGS. 3A-3B) of the motion tracking system, and/or while the sensors are provided on a target tracked with the sensors.

[0086] When carrying out the method 100, the magnetic field measurements received 101 in the computing device are the raw measurements (in some cases decomposed into intensity and inclination of the measured magnetic fields) of the magnetometer in the sensors so that the computing device may determine if there are magnetic disturbances affecting the measurements, whereas for the motion tracking itself preferably the measurements outputted by the sensor fusion algorithm are provided to the computing device.

[0087] The method 100 further comprises a step of digitally processing 102 each of the magnetic field measurements. The digital processing is carried out by the computing device so as to determine if one or more sensors have sensed a magnetic field with a magnetic disturbance, and this is done by processing 102 the magnetic field measurements for each pair of sensors of the motion tracking system.

[0088] The computing device, by means of at least one processor and at least one memory thereof, digitally computes a difference between the intensity of the magnetic field measurement of one sensor (i.e. first sensor) and the intensity of the magnetic field measurement of another sensor (i.e. second sensor), and it also computes a difference (i.e. an angle) between the inclination of the magnetic field measurement of the first sensor and the inclination of the magnetic field measurement of the second sensor. The computing device then establishes whether the difference of the intensities and/or the inclinations (either taken alone, i.e. difference of intensities or difference of inclinations, or combined in an equation) exceeds a threshold value, and/or the (x,y) point having the difference of intensities or inclinations as X coordinate and the other one of the difference of intensities or inclinations as Y coordinate falls outside of a threshold area. The same digital processing 102 is carried out with the magnetic field measurements of the remaining sensors of the motion tracking system.

[0089] In some embodiments, such as the embodiment of FIG. 2, the computing device determines if any difference of intensities exceeds 103 an intensity threshold, and also determines if any difference of inclinations exceeds 104 an inclination threshold; furthermore, the computing device also computes, for the magnetic field measurements for each pair of sensors of the motion tracking system, a weighted sum of the difference of intensities and the difference of inclinations and establishes whether it exceeds 105 a combined threshold. The weighted sum can be expressed with the following formula: W1 diff_intensities+W2*diff_inclinations, where W1 and W2 are weighting factors, diff_intensities is the difference between the intensity of the magnetic field measurement of the first and the intensity of the magnetic field measurement of the second sensors, and diff_inclinations is the difference between the inclination of the magnetic field measurement of the first sensor and the inclination of the magnetic field measurement of the second sensor.

[0090] Even if at one point the computing device determines that a difference of intensity, or a difference of inclination, or a weighted sum exceeds 103-105 the respective threshold, the computing device further digitally processes the remaining pairs of magnetic field measurements in order to determine which specific sensor or sensors is or are affected by the magnetic disturbances (one of the two sensors whereby it is determined that there are magnetic disturbances may not be affected significantly by the magnetic disturbances), and/or in order to determine which other sensors also provide disturbed magnetic field measurements. Depending on the number of sensors affected by the magnetic disturbances and/or where the same are to be placed on the target, the operation of the motion tracking system is adjusted 106 in one way or another during the following step of the method 100.

[0091] By way of example, if the motion tracking system has four sensors, the computing device computes the differences between the magnetic field measurement (the intensity and the inclination thereof) of the first sensor and the magnetic field measurement (the intensity and the inclination thereof) of each of the second, third, and fourth sensors, makes the weighted sum thereof, and compares each resulting value with the respective threshold, computes the differences between the magnetic field measurement (the intensity and the inclination thereof) of the second sensor and the magnetic field measurement (the intensity and the inclination thereof) of each of the first, third and fourth sensors, makes the weighted sum thereof, and compares each resulting value with the respective threshold, and so on. In those embodiments in which the intensity and the inclination of the magnetic field measurements are filtered, e.g. with a low-pass filter, the aforementioned computations of differences and weighted sums are made with the filtered intensities and inclinations. Preferably, the time difference with which the sensors made the measurements is as small as possible.

[0092] The method further comprises the step of adjusting the operation of the motion tracking system if any one of the differences computed exceeds a threshold value, and/or the (x,y) point falls outside of a threshold area. In the embodiment of FIG. 2, the operation of the motion tracking system is adjusted if at least one of the differences of intensities exceeds 103 the intensity threshold, and/or at least one of the differences of inclinations exceeds 104 the inclination threshold, and/or at least one weighted sum exceeds 105 the combined threshold.

[0093] The method 100 may be repeated a number of times so as to dynamically adjust 106 the operation of the motion tracking system based on a more recent state of the sensors and the magnetic fields sensed. For instance, the method 100 may be repeated every time all the sensors make a new measurement, or every time all the sensors have made e.g. ten, twenty, a hundred, a thousand, etc. new measurements, so that the computing device is not continuously using processing power for determining the existence of magnetic disturbances. In fact, the magnetic disturbances are usually not instantaneous (i.e. they do not appear at one time instant and disappear shortly thereafter), therefore the repetition of the method 100 may be staggered, and the frequency with which it is repeated may be selected based on the requirements of the motion tracking application and the environment where the motion tracking is conducted; the latter is important as well since magnetic disturbances depend on the environment, the devices therein and the operation of said devices.

[0094] The operation of the motion tracking system may be adjusted 106 in at least one of the following ways: [0095] By not processing 107 the magnetic field measurements in a sensor fusion algorithm of the respective sensors of the motion tracking system. The sensors (those for which the computing device has determined that the difference of the intensities and/or the inclinations exceeds the threshold value, and/or the (x,y) point falls outside of the threshold area) are commanded not to process, in the sensor fusion algorithm, magnetic field measurements until commanded otherwise. Since it is not known which measurements are affected by the magnetic disturbances, from the moment they are commanded not to process the measurements they disregard all further measurements until the computing device determines that each of the difference of intensities, the difference of inclinations and the weighted sum corresponding to later measurements does not exceed 103-105 respective thresholds; [0096] By digitally adjusting 108 one of a motion tracking procedure 110 or a physical exercise evaluation procedure 111; [0097] By providing 109 at least one user perceptible signal indicative of the computing device having determined that at least one magnetic field measurement is anomalous.

[0098] The physical exercise evaluation procedure 111 to be adjusted 108 is, for example but not limited to, the evaluation procedure of patent document EP18398006, which is a method for determining a correct reproduction of a movement of a target based on a plurality of orientations thereof at different time instants, the different time instants at least including first and second time instants, the second time instant being posterior to the first time instant, the movement being defined by at least a first predetermined constraint, the first predetermined constraint being defined for first and second orientations of the plurality of orientations and defined by a start angle, an end angle and a first plane definition. In the physical exercise evaluation procedure 111 first and second planes are provided, each defined by the first plane definition, corresponding to the first and second time instants, respectively; a first pair of vectors is provided by projecting the first orientation and the second orientation, corresponding to the first time instant, onto the first plane; a second pair of vectors is provided by projecting the first orientation and the second orientation, corresponding to the second time instant, onto the second plane; first and second angles between the pair of vectors of the first and second pairs of vectors, respectively, are computed; and the correct reproduction of the movement is determined if the first angle is equal to or less than the start angle, and the second angle is equal to or greater than the end angle. The movement is sometimes defined by further predetermined constraints (e.g. second, third, fourth or more predetermined constraints), each defined for two orientations and defined by a start angle, an end angle, and a plane definition, and in order to determine the correct reproduction of the movement the different predetermined constraints shall be met by the tracked target. The adjustment 108 of the physical exercise evaluation procedure 111 entails disregarding or removing one, some or all of these further predetermined constraints from the procedure so as to reduce the number of predetermined constraints to be met for determining the correct reproduction of the movement.

[0099] FIGS. 3A-3B show a holding device 50 of a motion tracking system in accordance with an embodiment.

[0100] The holding device 50, which may be part of a motion tracking system such as the motion tracking system 10 of FIG. 1, comprises a plurality of cavities 55-58 adapted to receive the sensors 21-24 as illustrated in FIG. 3B.

[0101] In this example, the cavities 55-58 are dimensioned such that the sensors 21-24 may be introduced with a particular orientation thereof. The sensors 21-24 may fit tightly or with some play. The holding device 50 may be used for one or more of the following purposes: for storing the sensors 21-24 while the same are not in use, for determining whether the sensors 21-24 require to be calibrated, and/or even for calibrating the sensors 21-24 in a simple and effective manner, in which case the holding device 50 is rotated for calibrating the sensors 21-24 while they are introduced therein (depending on the type of rotation necessary for calibrating the sensors, it may be necessary to cover the sensors 21-24 with the hand during the calibration procedure so that they do not fall off from the holding device 50).

[0102] In some other examples, the holding device 50 comprises a single cavity or more than one cavity in which two or more sensors may be introduced side-by-side such that the two or more sensors have fixed relative orientations (so that each sensor does not change its orientation with respect to the other sensors). To this end, the cavity or cavities may include one or more spacing elements that provide a gap between each pair of sensors.

[0103] While the sensors 21-24 are introduced in the holding device 50, they may provide the magnetic field measurements so that a computing device may determine if there are magnetic disturbances in said measurements, for instance as described with reference to the method 100 of FIG. 2.

[0104] FIG. 4 shows a graph with a threshold area 70.

[0105] The threshold area 70 is defined by a curve and the X and Y axes, the latter corresponding to the norm or intensity difference, and the dip or inclination difference, respectively. It is readily apparent that the X and Y axes could be interchanged.

[0106] Also in the graph are shown first and second (x,y) points 80, 81 (illustrated with circles). The first (x,y) point 80 has a first difference of intensities as X coordinate and a first difference of inclinations as Y coordinate, both first differences being computed for a first pair of magnetic field measurements. The second (x,y) point 81 has a second difference of intensities as X coordinate and a second difference of inclinations as Y coordinate, both second differences being computed for a second pair of magnetic field measurements. The first (x,y) point 80 falls within the threshold area 70, thus it is determined that no magnetic disturbance has affected the magnetic field measurements of the first pair, whereas the second (x,y) point 81 falls outside of the threshold area 70, hence it is determined that a magnetic disturbance has affected the at least one magnetic field measurement of the second pair.

[0107] FIG. 5 shows a graph with a threshold area 71, and first and second threshold values 72, 73.

[0108] The threshold area 71 is defined by the first and second threshold values (TH1, TH2) 72, 73, thereby resulting in a rectangular area. As in the graph of FIG. 4, the X axis of the graph corresponds to the to the norm or intensity difference, and the Y axis of the graph corresponds to the dip or inclination difference, even though they could be interchanged.

[0109] Also in the graph are shown first, second and third (x,y) points 82-84 (illustrated with circles). Each of the first, second and third (x,y) points 82-84 has a difference of intensities as X coordinate and a difference of inclinations as Y coordinate, both differences being computed for first, second and third pair of magnetic field measurements, respectively. The first (x,y) point 82 falls within the threshold area 71, which also means that the difference of intensities thereof does not exceed the intensity threshold (TH2) 73 and the difference of inclinations thereof does not exceed the inclination threshold (TH1) 72. Each of the second and third (x,y) points 83, 84 fall outside of the threshold area 71. In particular, the difference of intensities of the second (x,y) point 83 does not exceed the intensity threshold (TH2) 73 but the difference of inclinations thereof exceeds the inclination threshold (TH1) 72; the difference of intensities and the difference of inclinations of the third (x,y) point 84 both exceed the respective thresholds (TH1, TH2) 72, 73.

[0110] In this text, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.

[0111] On the other hand, the invention is obviously not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the invention as defined in the claims.