US20030144088A1

US20030144088A1 - Method and apparatus for analyzing a golf stroke

Info

Publication number: US20030144088A1
Application number: US10/314,434
Authority: US
Inventors: George Shoane
Original assignee: Rutgers State University of New Jersey
Current assignee: Rutgers State University of New Jersey
Priority date: 2001-06-07
Filing date: 2002-12-06
Publication date: 2003-07-31
Also published as: WO2002102475A1; WO2002102475A9

Abstract

A method of analyzing and practicing golf strokes, such as putting strokes, is provided. A surface is provided, wherein a golfer can practice one or more strokes in an environment simulating components of a golf course, such as a green. A club movement detector embedded in the surface and comprising a plurality of photodetectors and associated circuitry determines the position and velocity of the club face A head movement sensor detects rotational movement of the golfer's head during the golf stroke. An eye movement sensor detects movement of the eyes of the golfer during the golf stroke. A processor connected to the club movement sensor, eye movement sensor, and head movements sensor gathers movement data during the golf stroke and produces measurements corresponding to the golf stroke, such as eye, head, and club movement of the golfer. The invention includes measuring head movement data and wirelessly transmitting same for remote analysis during a golf stroke. Club head movement is sensed by an infrared ranger placed along a line perpendicular to the face of the clubhead. Eye, head, and club movement data can be combined into one or more serialized data streams, and transmitted wirelessly over one or more RF channels for remote reception and processing. Finger, wrist, and elbow movements can also be measured and analyzed during a golf stroke or a free throw setting.

Description

RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. Patent Application Serial No. 10/107,910, filed Mar. 27, 2002, now U.S. Pat. No. _______, issued ______, which is related to and claims the benefit of the U.S. Provisional Application Serial No. 60/296,527 filed Jun. 7, 2001, and U.S. Provisional Application Serial No. 60/317,944 filed Sep. 10, 2001. This application is also a continuation-in-part application of PCT Application Serial No. PCT/US02/18243 filed Jun. 7, 2002, which is related to and claims the priority of U.S. Patent Application Serial No. 10/107,910 filed Mar. 27, 2002, now U.S. Pat. No. ______, issued _______, and U.S. Provisional Application Serial No. 60/371,699 filed Apr. 11, 2002. The entire disclosures of all of these related applications are expressly incorporated herein by reference.[0001]

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for golf stroke analysis, and more particularly, to a method and apparatus for analyzing components of a golf stroke including club face movement and the physical movement of a golfer during a stroke. The present invention also relates to a method and apparatus for allowing golfers to practice and improve their golf strokes.

2. Related Art

In the field of sports, generally, and in the game of golf, particularly, there has been an increasing need to address specific questions posed by athletes concerning the body's forces and motions during athletic activities. Much information has been acquired about the golf swing and the physical forces associated therewith, including forces impacting the golf ball. Such information has been obtained using high-speed photography and videotape, and the components of the golf swing have been studied in great detail during, at least, the past 50 years. Unfortunately, such methodologies do not allow for real-time analysis of a golfers'stroke.

The putting stroke is a crucial element in the game of golf. Statistics compiled by the Professional Golfer's Association show that approximately 40% of the total strokes by professional golfers in a given round are spent on putting. Golf teaching professionals and sports psychologists frequently teach beginning and experienced golfers the importance of minimal or no eye and head movements throughout the putting stroke. Reduced eye movement is particularly important to successful execution of the putting stroke, because eye fixation at locations other than the ball can cause improper strokes and missed puts. Further, reduced head movement allows a golfer to maintain a stable image of a putting surface, thereby enhancing the golfer's accuracy at putting. If the golfer's head moves during the stroke, putting misalignment and missed putts can result. Additionally, putter head velocity and acceleration, in conjunction with a golfer's grip, are useful indicators of a golfer's putting accuracy and ability.

What would be desirable, but has not yet been provided, is a system for analyzing the aforementioned aspects of a golfer's putting stroke, and producing real-time results indicating the effectiveness and accuracy of the putting stroke, and for allowing golfers to practice their strokes while also receiving feedback information.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and apparatus for analyzing golf strokes

It is another object of the present invention to provide a method and apparatus for analyzing putting strokes.

It is an additional object of the present invention to provide a method and apparatus for allowing a golfer to practice and improve his or her golf stroke, while receiving feedback thereon and allowing for the comparison of measurements of the swing to measurements of a professional golfer's swing.

It is a further object of the present invention to provide a method and apparatus for measuring eye, head, and club movement during a golf stroke, including a putting stroke.

It is an additional object of the present invention to provide a method and apparatus for analyzing a golf stroke including a club movement sensor for measuring club movement.

It is still another object of the present invention to provide a method and apparatus for analyzing a golf stroke including a head movement sensor for measuring head movements during the stroke.

It is a further object of the present invention to provide a method and apparatus for analyzing a golf stroke including an eye movement sensor for measuring eye movements during the stroke.

It is another object of the present invention to provide a method and apparatus for analyzing a golf stroke including a processor for acquiring eye, head, and club movement data and processing same.

It is still another object of the present invention to provide a method and apparatus for comparing eye, head, and club movement data of a golfer to eye, head, and club movement data of golfers of various experience levels.

It is yet another object of the present invention to provide a method and apparatus for determining the effect of different golf grips on eye, head, and club movement during a golf stroke, including a putting stroke.

The present invention relates to a method and apparatus for analyzing and practicing a golf stroke, particularly a golf putting stroke. A putting platform is provided, wherein a golfer can putt in an environment simulating a golf green. Information regarding the golfer's eye, head, and club movements during the putting stroke are acquired using a plurality of sensing devices. A club movement sensor in the putting surface measures club movements during the stroke, without requiring attachment to the club. Eye movement sensors measure left and right eye movements of the golfer during putting. A head movement sensor tracks rotational movement of the golfer's head during the putting strokes. The acquired motion data are gathered simultaneously by a processor, and time traces of club, head, and eye movement may be generated. The time traces can be compared to time traces of golfers of various experience levels to determine the accuracy and efficiency of the golfer's putting stroke. Additionally, the effect of various golfing grips on eye, head, and club movement can be measured and analyzed. As such, a golfer can practice and improve his or her golf stroke, and compare measurements thereof to measurements of others, such as professionals.

In an embodiment of the present invention, eye, club, and head movement information is monitored by a plurality of sensors including an infrared club movement sensor, an infrared eye movement sensor, and an accelerometer for measuring head movement. The infrared club movement sensor is placed behind the golf club and along the swing path of the club. An infrared beam is projected from the sensor and bounces off of a reflective back portion of the clubhead. The reflected beam is received by the sensor, and the distance of the clubhead from the sensor is measured. The measured distance is utilized to calculate clubhead movement. Information from the sensors can be transmitted by wire, or wirelessly through one or more RF channels.

Output from the sensors of the present invention is gathered and processed by a plurality of controllers. The controllers interact to provide a single serialized data stream having information corresponding to head, eye, and putter movement. The data stream can be transmitted wirelessly over one or more RF channels, and can be remotely received for processing. Additionally, finger, wrist, and elbow movement can be measured during a golf stroke or a free throw, processed by a controller to produce a serialized data stream, and transmitted wirelessly for remote reception and processing.

BRIEF DESCRIPTION OF THE DRAWINGS

Other important objects and features of the invention will be apparent from the following Detailed Description of the Invention taken in connection with the accompanying drawings in which: [0021]
FIG. 1 is a perspective view of the apparatus of the present invention during use by a golfer. [0022]
FIG. 2[0023] a is a top view of the club movement sensor shown in FIG. 1.
FIG. 2[0024] b is a side view of the club movement sensor and a portion of the putting surface shown in FIG. 1.
FIG. 2[0025] c is an end view of the club movement sensor and a portion of the putting surface shown in FIG. 1.
FIG. 3 is a perspective view of an embodiment of the head movement sensor shown in FIG. 1. [0026]
FIG. 4[0027] a is a side view of the eye movement sensor shown in FIG. 1.
FIG. 4[0028] b is a side view showing the eye movement sensor of FIG. 1 shown in greater detail.
FIG. 5 is a block diagram showing components of the present invention. [0029]
FIG. 6 is a schematic diagram showing a circuit configuration of the club movement sensor of the present invention. [0030]
FIG. 7 is a diagram showing operation of the club movement sensor. [0031]
FIG. 8 is a graph showing a time trace of club movement during a putting stroke. [0032]
FIG. 9 is a graph showing a time trace of eye movement during a putting stroke. [0033]
FIG. 10 is a graph showing a time trace of head movement during a putting stroke. [0034]
FIG. 11[0035] a is a graph showing a time trace of club movement of an experienced golfer during a putting stroke.
FIG. 11[0036] b is a graph showing a time trace of club movement of a novice golfer during a putting stroke.
FIG. 12 is a graph showing simultaneous time traces of eye, head, and club movement during a putting stroke. [0037]
FIG. 13[0038] a is a graph showing simultaneous time traces of eye, head, and club movement of a novice golfer during a putting stroke.
FIG. 13[0039] b is a graph showing simultaneous time traces of eye, head, and club movement of an experienced golfer during a putting stroke.
FIG. 14 is a graph showing time traces of eye, head, and club movement when a conventional golf grip is used during a putting stroke. [0040]
FIG. 15 is a graph showing time traces of eye, head, and club movement when a cross-handed golf grip is used during a putting stroke. [0041]
FIG. 16 is a graph showing time traces of eye, head, and club movement when a one-handed golf grip is used during a putting stroke. [0042]
FIG. 17 is a table showing results of statistical analysis of conventional, cross-hand, and one-handed grips used during 3 foot and 9 foot putts. [0043]
FIG. 18 is a photograph showing an embodiment of the present invention for analyzing head movement during a golf stroke uses an accelerometer and that wirelessly transmits the acquired data to a processor. [0044]
FIG. 19 shows an embodiment of a head movement sensor of FIG. 18. [0045]
FIG. 20 is a schematic showing a circuit for use with the embodiment of the present invention shown in FIG. 18, for converting accelerometer output to head rotation data. [0046]
FIG. 21 is a graph showing time traces of putter, eye, and head movement measured using the apparatus of FIG. 18. [0047]
FIG. 22[0048] a is a top view showing an alternate embodiment of the club movement sensor of the present invention.
FIG. 22[0049] b is a front view of the club movement sensor of FIG. 22a.
FIG. 22[0050] c is a schematic showing a circuit for filtering and processing output of the club movement sensor of FIG. 22a.
FIG. 23 is a diagram showing an alternate embodiment of the eye movement sensor of the present invention. [0051]
FIG.24[0052] a is a block diagram showing a circuit according to the present invention for producing a combined serial data stream containing eye, club, and head movement data.
FIG. 24[0053] b is a block diagram showing a sample data stream produced by the circuit of FIG. 24a.
FIG. 25[0054] a is a schematic showing a circuit for processing finger, wrist, and elbow acceleration signals.
FIG. 25[0055] b is a block diagram showing a circuit according to the present invention for producing a combined serial data stream containing eye, finger, wrist, and elbow acceleration data.
FIG. 25[0056] c is a block diagram showing the circuit of FIG. 25b in greater detail.
FIG. 26[0057] a is a view showing an apparatus according to the present invention for measuring finger, wrist, and elbow movement during a free throw.
FIG. 26[0058] b is a view showing the apparatus of FIG. 26a in use during a basketball throw.
FIG. 27 is a graph showing time traces of finger, wrist, elbow, and eye movements during a free throw. [0059]

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method and apparatus for analyzing golf strokes, particularly a putting stroke. A variety of physical movements can be tracked and analyzed during the golf stroke, such as eye, head, and club movement, and time traces thereof can be produced in real time. The sampled data can be compared with pre-recorded time traces of golfers at different experience levels, to determine the accuracy and efficiency of the golfer's stroke. Further, the effects of various golf grips on eye, head, and club movement can be determined. A golfer can practice and improve his or her game, and compare measurements relating to his or her golf stroke to measurements of professionals. [0060]
FIG. 1 is a perspective view of an embodiment of the present invention. The system of the present invention comprises a variety of components which, operating in conjunction, provide golf stroke analysis. A putting [0061] surface 80 is provided for a golfer 20 for taking practice putting strokes using any club 30 and golf ball 34 known in the art. Movement of club 30 along a path generally indicated by line 32 can be analyzed by club movement sensor 60, embedded in putting surface 80, as will be hereinafter further described. Importantly, club movement sensor 60 does not obstruct the path of golf ball 34, allowing golfer 20 to putt normally and (hopefully) sink golf ball 34 into hole 82. Further, putting movement sensor 60 allows for the analysis of movement of club 30, without requiring the attachment of any apparatus thereto.
In an embodiment of the present invention, putting [0062] surface 80 can be partitioned into two or more surfaces that can be positioned lengthwise to allow for putts of varying lengths. For example, two sections of putting surface 80 can be joined to allow for putts of three feet in length, additional sections can be added to allow for putts of nine feet in length Any combination of sections of putting surface 80 can provided for allowing putts of any desired length.
Movement of the head of [0063] golfer 20 during the putting stroke can also be measured by the present invention. Rotational movement of the head of golfer 20, indicated generally along axis 24, can be measured by head movement sensor 40, attached to helmet 41, as will be hereinafter further described. It is to be understood that other types of head movement (i.e., side-to-side) are contemplated by the present invention and considered within the scope thereof. Head movement sensor 40 can be any sensor known in the art, e.g., an accelerometer with wireless transmitter and receiver, that is capable of measuring rotational movement.
Eye movements of [0064] golfer 20 can also be analyzed by the present invention by eye movement sensor 50, as will be hereinafter further described. In a preferred embodiment, eye movement sensor 50 is an infrared device that tracks motion of both right and left eyes of a golfer Other eye movement sensors are considered within the scope of the invention.
Movement data generated by [0065] eye movement sensor 50, head movement sensor 40, and club movement sensor 60, is transmitted to processor 70 by cables 72. It is conceivable that other means for transmitting the acquired data, such as radio frequency (“RF”) or infrared (“IR”) transmission, can be utilized to channel the acquired movement data to processor 70. The movement information gathered by processor 70 during a putting stroke can then be analyzed to determine the accuracy and efficiency of the putting stroke.
FIG. 2[0066] a is a top view of the club movement sensor of the present invention. Putting motion sensor 60 comprises first detector array 62, and second detector array 64, each of the detectors having a plurality of detectors 66. In a preferred embodiment of the invention, detectors 66 are infrared photo transistors. As a club moves along axis 32, shadows are cast on one or more of the detectors 66, whereupon the one or more detectors 66 turn electrically off The outputs of detectors 66 of both first detector allay 62 and second detector array 64 are then fed to processor 70 via cables 72. The second detector array 64 is positioned to track movement of the club to impact. Thereafter, the first detector array 62 is positioned to track movement of the putter after impact. The first detector array 62 is offset from the second detector array 64, so that golf ball 34 can travel freely along path 36 without traveling over detectors 66 of first detector array 62. Other spatial configurations of club movement sensor 60, first detector array 62, and second detector array 64 are considered within the scope of the present invention.
FIG. 2[0067] b is a side view of the club movement sensor 60 and putting surface 80 of the present invention. In a preferred embodiment of the present invention, detectors 66 are positioned at increasing intervals away from the ball 34, in both frontward and rearward directions. For example, the first four detectors 66 of first detector array 62 and second detector array 64, closest to ball 34, are spaced approximately ½ inch apart. The next two detectors are spaced 1 inch apart. The remaining two detectors are then spaced 2 inches apart. It is to be understood that additional detectors and other spatial arrangements are considered within the scope of the present invention.
FIG. 2[0068] c is an end view of the club movement sensor 60 and putting surface 80 of the present invention. The surface 80 can be constructed of wood boards 82, 84, and 86, such as particle boards, which are joined together and covered with artificial grass to form putting surface 80. Other materials capable of forming putting surface 80 are considered within the scope of the present invention. Putting surface 80 contains cavities for retaining embedded detector arrays 62 and 64.
FIG. 3 is a perspective view of the head movement sensor of the present invention. Rotational movement of a golfer's head about [0069] axis 24 can be measured during a putting stroke by sensor 44. A golfer wears hat or helmet 41 which transfers rotational movement of the golfer's head to sensor 44, via interconnections 42 and 43. Interconnections 42 and 43 are designed to mate interchangeably, and allow a user to step away from sensor 44 to disengage therefrom. It may be desirable to magnetize these components to facilitate engagement thereof Interconnection 42 is attached to hat or helmet 41, and interconnection 43 is attached to sensor 44. Sensor 44 can be any sensor in the art that is capable of measuring rotational movement, such as a potentiomenter. According to an embodiment of the invention, sensor 44 is mounted via pivot 45 to a fixed surface, and output from sensor 44 is transmitted via cables 72. It is to be understood that various other configurations are considered within the scope of the invention. For example, sensor 44 could be mounted on the hat or helmet 41, and could be self-contained, i.e., not attached to a fixed surface. The sensor could contain a pendulum such that when one rotates his or her head, a reading is taken. Further, this reading could be wirelessly transmitted to the processor. Additionally, other headgear can be used to receive the golfer's head and transfer movement thereof to a sensor.
FIG. 4[0070] a is a side view of the eye movement sensor 50 of the present invention. Eye movement sensor 50 can be any sensor known in the art that is capable of measuring eye movements, such as a Skalar-Iris Model 6500 helmet-mounted infrared reflection device. Other comparable detection devices can be used with the present invention without departing from the scope thereof In a preferred embodiment, eye motion sensor 50 contains one or more infrared detectors 52 that are pointed generally in the direction of the golfer's eyes and measure eye motion of the golfer (i.e., left-to-right and right-to-left eye motion). Output from the one or more infrared detectors 52 can be sent to a processor via cables 72, or wirelessly. Optionally, eye motion sensor 50 can be affixed to hat or helmet 41 via frame 54, or formed integrally therewith. Alternatively, the sensors can be incorporated on eyewear. Preferably, hat or helmet 41 and eye motion sensor 50 are manufactured to be lightweight, so that a golfer experiences minimal to no discomfort while wearing same during a golf stroke.
FIG. 4[0071] b is a side view showing the eye movement sensor 50 of the present invention shown in greater detail. Movements of a golfer's eyes, such as eye 26, can be tracked by infrared detectors 52. In a preferred embodiment of the present invention, infrared detectors 52 of eye movement sensor 50 have a linear range of +/−25 degrees, a combined resolution of 5 minutes of arc, and a bandwidth of 200 Hz, but these tolerances are not required. Voltage output signals of eye movement sensor 50 represent eye movements of the golfer's eyes, and can be analyzed by a processor.
FIG. 5 is a block diagram showing component parts of the present invention. Outputs from the [0072] head movement sensor 40 and eye movement sensor 50 are connected to analog-to-digital (A/D) converters 90 and 92, respectively. Club movement sensor 60 is connected to digital input port 94. The resulting digital signals derived fiom each of the sensors 40, 50, and 60 are then processed in real time by processor 70. Processor 70 can be any computer system known in the art. In a preferred embodiment of the present invention, processor 70 acquires the digitized movement data from each of the sensors, and outputs same. Such output may comprise synchronized time trace plots indicating movement of the right eye, left eye, club, and head of the golfer. As shown in FIG. 5, such data can be output through numerous channels (i.e., channels 1 through 4) for presentation to the golfer or for further data processing.
FIG. 6 is a schematic diagram showing an example of a circuit configuration of the [0073] club movement sensor 60 of the present invention. A plurality of infrared sensors, such as photo transistors Q₁through Q_n, can be connected to provide club movement detection. For purposes of illustration, only photo transistors Q₁through Q₄are shown connected in the circuit of FIG. 6. Further, other light-sensing devices, such as CdS photocells, can be used in place of the photo transistors. Each of photo transistors Q₁through Q₄are connected to difference amplifiers D₁through D₄, which reduce noise in the signals generated by each of photo transistors Q₁through Q₄. Further, difference amplifiers D₁through D₄allow for the generation of an electrical signal corresponding to the leading edge (i.e., face) of a club passed over one or more of photo transistors Q₁through Q₄. Connected to difference amplifiers D₁through D₄are comparators C₁through C₄, which compare the outputs of each of difference amplifiers D₁through D₄to a threshold voltage V_TIt is to be understood that other circuit configurations of club movement sensor 60 not depicted in FIG. 6 are considered within the scope of the present invention. In a preferred embodiment of the invention, 16 photo transistors are provided in club movement sensor 60 to produce a 16 bit digital signal in which one of the bits indicates the position of the club face.
FIG. 7 is a diagram showing operation of the [0074] club movement sensor 60. Club 30, having a face 31, is passed over photo transistors of the club movement sensor 60, shown illustratively as Q₁through Q₄, generally along path 32 of a putting stroke. At a given point along the path 32 of the putting stroke, club 30 casts a shadow over one or more of the photo transistors of club movement sensor 60, turning same electrically off As shown, club 30 casts a shadow over photo transistors Q₂and Q₃, turning them to an off state, while photo transistors Q₁and Q₄remain in an electrically on state. In an illustrative embodiment, the on state of the photo transistors is indicated as a voltage of 0 volts, while the off state is indicated as a voltage of +5 volts.
Voltage outputs from each of photo transistors Q[0075] ₁and Q₄are then sent to difference amplifiers D₁through D₄, wherein outputs from two of the photo transistors are processed by each of the difference amplifiers. When the input voltage of a first phototransistor connected to one of the difference amplifiers is lower than the input voltage of the second phototransistor, a negative voltage is produced. Conversely, when the input voltage of the first phototransistor is lower than the input voltage of the second phototransistor, a positive voltage is produced. Further, when the input voltages of the photo transistors are equal, zero voltage is produced. Thus, as shown in the illustrative embodiment of FIG. 7, voltage of zero produced by Q₁and a voltage of +5 volts produced by Q₂cause difference amplifier D₁to emit a voltage of −5 volts.
Outputs from each of the difference amplifiers D[0076] ₁through D₄are then sent to comparators C₁through C₄, and are compared thereby to a threshold voltage V_T. In a preferred embodiment of the present invention, V_Tis 0.7 volts. Other values can be substituted for V_T. For input voltages that fall below V_T, a negative voltage (i.e., −12 volts) is produced. Conversely, for input voltages that exceed V_T, a positive voltage (i.e., +5 volts) is produced. Thus, as shown in FIG. 7, a voltage of −5 volts provided by difference amplifier D_q, which is lower than V_Tof −0.7 volts, an output voltage of −12 volts is produced by comparator C₁. Accordingly, the position of face 31 of club 30 can be indicated by a single positive voltage produced by one of the comparators. Therefore, a voltage of +5 volts produced by comparator C₃indicates the position of club face 31 amongst the plurality of photo transistors.
Outputs from the sensors of the present invention can be utilized to produce time traces corresponding to eye, club, and head movements. In a preferred embodiment of the invention, C++ and MATLAB programs are used to generate position and velocity graphs as functions of time for club movement, left eye movement, right eye movement, and head movement. The generated time traces/graphs can then be compared amongst golfers at varying skill levels to indicate the efficiency and accuracy of the subject golfer. It is well known that any general purpose computer, programmed by languages known in the art, can be used to produce the time traces. [0077]
It should be apparent to those skilled in the art that the present invention can be adapted to allow analysis and practice of all types of golf strokes, such as putting, driving strokes, iron stokes, chips, pitches, or other stokes. The apparatus of the present invention can be installed in commercial driving ranges, golf courses, or other practice locations, allowing golfers to quickly gauge the efficiency of their golf strokes and to receive feedback on practice strokes by returning real-time measurements of the strokes and comparing same to measurements of professional golfers. Further, the present invention can be adapted to allow practice and analysis of other sports involving stroke-like movements. [0078]

EXAMPLE

The apparatus of the present invention was experimentally tested on twelve volunteers, divided into three groups according to skill levels. Individuals with handicaps between 0 and 9 were placed in the first group, and individuals with handicaps between 10 and 20 were placed into the second group. Novices were placed into the third group. Each group had four volunteers. Each subject made twenty 3-foot putts and twenty 9-foot putts using the present invention, and results for each of the volunteers were compared. It was found that the typical low-handicapper exhibited a small head rotation (i.e., clockwise as seen from top) during the backstroke, compensated for by a smooth eye movement (i.e., vestibulo-ocular reflex), wherein steady eye fixation on the ball was maintained. Head rotation appeared to be associated with a slight shoulder turn during the putting stroke, and occurred less frequently for 3-foot putts but occasionally appeared for 9-foot putts. The typical mid-handicapper demonstrated a similar response pattern, but additionally exhibited saccadic eye movements (i.e., fast jumps in fixation) during the backstroke and at the time of impact. The typical novice golfer showed relatively large head rotations and compensatory eye movements, and exhibited frequent erratic eye fixations through the backstroke and during impact. [0079]
FIGS. 8 through 10 are graphs showing examples of measurements of club, eye, and head movement achieved by the present invention. FIG. 8 is a graph showing time traces of club movement during a putting stroke produced by the present invention. Club position, measured in centimeters, is graphed as a function of time, measured in seconds. Positive and negative club position values indicate movements toward or away from the hole, respectively. Position of the club is represented as a solid line, while velocity of the club is represented as a dashed line. The point of impact with the ball is illustratively represented as a club position value of 0, occurring between 1 and 1.5 seconds. [0080]
FIG. 9 is a graph showing time traces of eye movement during a putting stroke. Eye movements for both left and right eyes of the subject are indicated in the top and bottom graphs, respectively. Prior to capturing eye movement data, the subject fixated on three known locations (i.e., left end, middle, and right end of the [0081] club movement sensor 60 of the present invention), in order to provide adequate calibration data. Eye movement data acquired during the putt was then measured with reference to the calibration data, and eye position was recorded as displacement in centimeters of the left and right eyes along putting surface 80. The solid line of the graph indicates eye displacement in centimeters. Further, the dashed line indicates eye velocity.
FIG. 10 is a graph showing a time trace of head movement during a putting stroke. Prior to acquiring head movement data, the [0082] head movement sensor 60 was pre-calibrated to provide conversion from a measured voltage change to a corresponding angular rotation of the potentiometer shaft, which in turn corresponded to an angular rotation of the subject's head. This angle was then converted to a displacement of a hypothetical beam emanating from the center of rotation of the head, approximated by the position of the center between the two eyes of the subject, and measured in centimeters As shown in the graph, head position is measured in centimeters from the center position of the head, and indicated as a solid line. The dashed line indicates head velocity.
FIG. 11[0083] a is a graph showing a time trace of club movement of an experienced golfer during a putting stroke. As can be seen, club movement is relatively smooth, with backward and forward movement being relatively uniform. These results can be compared to FIG. 11b, which shows a time trace of club movement of a novice golfer during a putting stroke. Backward movement is noticeably larger than forward movement, and there is a lack of uniformity between forward and backward movements.
FIG. 12 is a graph showing simultaneous time traces of eye, head, and club movement during a putting stroke. The dotted line across the four graphs indicates the moment in time in which the ball is struck. Thus, using the present invention, real-time plots of head, club, and eye movement can be generated simultaneously and compared. [0084]
FIG. 13[0085] a is a graph showing simultaneous time traces of eye, head, and club movement of a novice golfer during a putting stroke. The point of contact between the club face and the ball is represented in the graphs as occurring after 2 seconds. As can be seen from the graphs, a considerable amount of eye movement for both the left and right eyes of the subject occurred prior to the point of contact. Further, forward and backward club movements are not uniform, as there is greater backward movement than forward movement. Additionally, the occurrence of saccadic eye movement can be seen occurring prior to the putt.
FIG. 13[0086] b is a graph showing simultaneous time traces of eye, head, and club movement of an experienced golfer during a putting stroke. As can be seen, club, eye, and head movements for the experienced golfer appeared more uniform than the movements of the novice golfer, as shown in FIG. 13a. Club movements are also more uniform, with backward and forward movements being generally equal. Eye movements are significantly less than those of the novice golfer, and saccadic movements do not appear prior to contact between the club face and the ball. Additionally, head movement is reduced.
The present invention can also be utilized to determine the effect of various golf grips on putting performance. For example, club, eye, and head movements can be measured and compared for various golf grips, i.e., conventional, cross-hand, and single-hand grips. Results using these grips are shown in FIGS. [0087] 14-16.
FIG. 14 is a graph showing time traces of eye, head, and club movement when a conventional golf grip is used during a putting stroke. Time traces of club, eye, and head movements are shown for a typical 9 foot put using a conventional golf grip. For all traces, position and velocity are indicated by solid and dashed lines, respectively. The vertical dashed lines indicate the duration of the putt starting from the beginning of the backstroke and ending at the point of impact with the ball. FIG. 15 is a graph showing time traces of eye, head, and club movement when a cross-handed golf grip is used during a putting stroke. FIG. 16 shows time traces using the one-handed grip. [0088]
The results shown in FIGS. [0089] 14-16 can be analyzed using statistical methods to determine the effect of the various grips on putting. FIG. 17 shows results of statistical analysis of conventional, cross-hand, and one-handed grips used during 3 feet and 9 feet putts. The results show differences between the putting grips for various parameters, including height to the subject's eyes, putt amplitude, putt duration, percentage of putts made, and STD of left eye, right eye, and head movements. To determine whether the difference between the results in adjacent columns are significant (i.e., p<0.1; H=1), one-tailed t-tests were performed.
Height to the subject's eyes was highest for one-handed grips, intermediate for conventional grips, and lowest for cross-handed grips. This can be attributed to the fact that one-handed subjects tended to stand more erect. Conversely, for cross-handed grips, the left hand is positioned lower on the club grip, thus lowering the left shoulder. Such a result tends to bring the head of the subject down as well, thus lowering the height of the head relative to the platform. The results for this category are the same for 3 and 9 foot putts. [0090]
Putt amplitude is not significantly different for the three putting grip styles for 3 foot putts. However, for 9 foot putts, amplitude for cross-handed grips are statistically significantly smaller than for either conventional or one-handed grips. This may be attributable to a restriction of right elbow motion in the backstroke, due to increased bending of the right elbow to compensate for a higher right hand position on the club. [0091]
Putt duration is longer for the one-handed grip than for either conventional or cross-handed grips, for both 3 and 9 foot putts. This may be due to the increased length of the swing arm (i.e., club plus hand and arm), in the one-handed putt. Hence, if one considers this as a pendulum motion, the increased length corresponds to an increase in the period of motion, resulting, in turn, in an increase in the duration of the putt. [0092]
The percentages of putts made appear to be higher for cross-handed grips than for either conventional or one-handed grips, for both 3 and 9 foot putts. However, such comparisons are not statistically significant, except for 9 foot putts where the percentage made is statistically significantly higher for cross-handed grip than for conventional grip (p=0.006). [0093]
The STD of combined right and left eye movements is lowest for one-handed grips, intermediate for cross-handed grips, and highest for conventional grips, for both 3 and 9 foot putts. The results are all statistically significant except for the comparison between cross-handed and conventional grips for 3 foot putts (p=0.312). [0094]
The STD of head movements is lower for one-handed grips, intermediate for crosshanded grips, and highest for conventional grips, for 3 foot putts. These results are statistically significant except for the comparison between one-handed grips and cross-handed grips (p=0.151). However, for the 9 foot putts, there are no statistically significant differences among the putting grip styles. These findings suggest that head motion plays a more important role in shorter (i.e., 3 foot) putts than for longer (i.e., 9 foot) putts. Further, the results indicate that one-handed grips, and to a lesser extent, cross-handed grips, result in less head motion during the putt. [0095]
FIG. 18 is a photograph showing an embodiment of the present invention for analyzing head movement during a golf stroke using an accelerometer and wirelessly transmitting the acquired data. As previously mentioned, the present invention can be implemented using one or more devices for wirelessly transmitting head and eye movement data during the stroke, thereby obviating the need for interconnecting cables between the head and eye movement sensors and other apparatuses. For example, as shown in FIG. 18, the present invention can be modified to provide a [0096] system 100 for wirelessly measuring head movement data during a golf stroke. The system 100 includes a helmet 110, similar in design to the helmet 41 of FIG. 1. The word “helmet” is meant to cover any suitable mechanism for support sensing equipment including, but not limited to, a hat, a headband that fully or partially surrounds the head, a visor, etc. Attached to the helmet 110 are a head movement sensor 120, a battery back 130, and eye movement sensors 140.
Head movement sensed by [0097] sensor 120 is wirelessly transmitted to receiver 160, for remote analysis. Advantageously, the sensor 120 allows for the untethered acquisition and analysis of head movement data during a golfer's putting stroke, without requiring the golfer to align his or her head with a stationary device and keep same in place during measurement. Head movement sensor 120 comprises an accelerometer, transmitter, and associated circuitry for measuring head movement and transmitting same wirelessly to receiver 160 for remote analysis. Any other device that can be used to acquire head rotation data is considered to be within the scope of the present invention. Battery packs 130 and 150 can be used to provide a power source to power sensor 120 and receiver 160. A 3 volt power source has been found to be sufficient.
FIG. 19 shows the [0098] head movement sensor 120 of the present invention in greater detail. The sensor 120 comprises an accelerometer 121, a transmitter 125, an antenna 126, and a power source 130. These components can be mounted on one or more circuit boards. As shown in FIG. 19, two circuit boards are interconnected. The power source 130 is shown remote from the circuit boards but could be positioned thereon. As shown in FIG. 19, the accelerometer 121 is mounted on one of the boards, and the wireless transmitter 125 and antenna 126 on the other board.
In a preferred embodiment of the present invention, the accelerometer comprises an ADXL202 single chip accelerometer manufactured by Analog Devices, Inc., which provides a 167 Hz rectangular wave signal having a duty cycle proportional to the acceleration. The duty cycle represents the ratio of the pulse-width to the period, and is proportional to the acceleration of the device in each of two sensitive axes (i.e., X and Y axes). The dimensions of the device are 10.6 mm×9.9 mm×5.5 mm. Two outputs are provided, based on sensors aligned in the X and Y directions within the plane of the device. The device is useful for measuring tilt, and it uses the force of gravity as an input vector to determine orientation of an object in space. A particular axis (i.e., X or Y axis) is most sensitive to tilting deviations when the device is parallel to the earth's surface. The accelerometer is capable of measuring both dynamic acceleration (i.e., vibration) or static acceleration (i.e., gravity). It is to be understood, however, that other devices capable of measuring head movement are considered within the scope of the invention and may be utilized without departing from the spirit of the invention. [0099]
If the [0100] accelerometer 121 is positioned on top of a subject's head and oriented in such a way that the Y-axis of the accelerometer is pointed toward the sky and in the direction behind the subject, then the X-axis is approximately parallel to the earth's surface (and parallel to an imaginary line drawn between the two eyes), providing sensitivity to tilt of the X-axis. The tilt of the X-axis is a result of the rotation of the head. Indeed, in testing the device during putts, it was found that the X-axis is much more sensitive to rotational as opposed to translational (i.e., side-to-side) motions of the head. Thus, the accelerometer can be used to measure head rotation during a golf swing or a putting stroke.
Preferably the transmitter [0101] 125 is the TR-1000 916.50 MHz hybrid transceiver manufactured by RFM, Inc. The device is well-suited to short-range wireless data applications, can serve as either a transmitter or a receiver, and its dimensions are 10.2 mm×7.1 mm×2.0 mm. The transmitter can operate using either on-off keying (OOK) or amplitude-shift keying (ASK). The operation of the transmitter is basically transparent to the other components of the overall device. The input analog signal to the transmitter is directly reflected in the output analog signal of the receiver. The distance between the transmitter and receiver can be up to 100 ft depending on environmental conditions. Thus, the transmitter/receiver combination can be easily implemented in a laboratory, pro-shop or driving-range environment. It is to be understood, however, that other transmitters/transceivers known in the art can be utilized with the present invention.
[0102] Sensor 120 can be implemented as follows the accelerometer 121 can be soldered onto a small circuit board 122 (2.5 mm×4.0 mm), and appropriate components such as capacitors and resistors can be added. The transmitter 125 can be soldered onto another similar-size circuit board 124. The two boards 122 and 124 can be mated by means of male and female complementary connectors on the two circuit boards. Of course, a single board could be used. The sensor 120 can then be adhered to a small flat plastic member that is glued to a stem. The stem can then be screwed onto a female stem fixed on the helmet 110 of FIG. 18. The orientation of the sensor 120 is adjusted so that the X-axis of the accelerometer is approximately parallel to a hypothetical line drawn between the subject's eyes. The accelerometer signal is input to the transmitter, which then emits a radio frequency signal. The signal consists of a rectangular wave whose duty cycle is proportional to the head rotation acceleration. The receiver 160 of FIG. 18 receives the signal and relays the duty cycle signal to remote processing circuitry. Clearly, the construction of the sensor 120 can be simplified in accordance with what is known in the art.
When the duty cycle is received by [0103] receiver 160, it is necessary to process same to provide a signal corresponding to head movement data. An illustrative circuit 200 for providing such processing is shown in the schematic of FIG. 20. The received duty cycle signal is fed into input 205 of circuit 200. In stage 210, the signal is integrated to provide an acceleration signal corresponding to rotational acceleration of the subject's head during a putting stroke. Then, in stage 220, the signal is fed through a biasing and gain stage to permit adjustment of circuit 200 to the most sensitive level (i.e., by tweaking the potentiometer of stage 220). The signal is then integrated by an operation amplifier in stage 230 to provide a velocity signal, and then integrated once again by another operation amplifier in stage 240 to produce a head rotation position signal. A final gain stage 250 provides a larger head rotation voltage signal for input to a computer or other system for analysis and/or further processing. Thus, the circuit 200 allows for the production of a head rotation position signal at output 255 given a duty cycle signal at input 205. Other circuit configurations for providing head rotation position signals are considered within the scope of the invention.
FIG. 21 is a graph showing time traces of putter, eye, and head movement measured using the wireless head measurement apparatus of the present invention. As can be seen in the bottom trace of the graph, head movement information can be acquired by the accelerometer of the present invention, transmitted wirelessly, processed, and analyzed to produce a time trace of high accuracy corresponding to head position during the putting stroke. The angle of head rotation about the spine axis has been converted to an equivalent movement of an imaginary beam projected perpendicularly to the face of the subject and onto the putting platform of the present invention. [0104]
It should also be noted that wireless data acquisition and transmission equipment and techniques can be used to wirelessly transmit data acquired by the eye movement sensors of the present invention. [0105]
FIG. 22[0106] a is a top view showing an alternate embodiment of the club movement sensor of the present invention. An infrared transceiver 200 is positioned on the putting surface 80, and measures movement of the head 31 of club 30. An infrared beam 210 is aimed at the clubhead 31, bounces off of same, and returns along path 215 where it is received by transceiver 200. Thus, for example, movement of the clubhead 30 can be monitored by the transceiver 200 as a golfer putts the ball 34 along path 36. Of course, other movements of the club 30 can be measured by the infrared transceiver 200. Movement sensed by the transceiver 200 is transmitted as an electrical signal wirelessly or along cable 205.
FIG. 22[0107] b is a front view of the transceiver 200 of the club movement sensor shown in FIG. 22a. The transceiver can be positioned at any location on the surface 80, but preferably, is positioned behind the clubhead and along a line perpendicular to the clubface 31 of the club 30. The transceiver 200 preferably includes an infrared LED 202 for transmitting a beam of infrared light to the clubhead, and an infrared phototransistor 204 for receiving the beam after it has been reflected fiom the clubhead. Preferably, the clubhead 31 includes a flat back surface for reflecting the beam. A putter sold by Octagon Golf, Inc. under the name “Octagon” provides such a suitable surface. Alternatively, a reflector can be attached to the back of an existing putter. The received beam is converted to an electrical signal by the phototransistor 204 and sent as an analog signal via the cable 205, or wirelessly, for processing.
In a preferred embodiment of the present invention, the [0108] transceiver 200 is the GP2Y0A02YK infrared ranger manufactured by SHARP, Inc. This sensor takes a continuous distance reading of the clubhead, and reports the distance as an analog voltage with a distance range of approximately 20 cm (8 inches) to 150 cm (60 inches). The ranger includes a three wire connection for providing power to the ranger and transmitting output voltage therefrom. Of course, any similar infrared device known in the art could be utilized as the transceiver 200 without departing from the spirit or scope of the present invention.
FIG. 22[0109] c is a schematic showing a circuit, indicated generally at 210, for filtering and processing output of the putter movement sensor of FIG. 22a. As mentioned previously, output from the transceiver 200 is in the form of an analog voltage corresponding to the distance of the clubhead from the transceiver. The output signal is provided via cable 205, or wirelessly, and is fed to a lowpass filter 215. The lowpass filter 215 filters the output signal to remove any undesired noise present therewith. The filtered signal is then sent from lowpass filter 215 to voltage follower 220. Finally, the signal is then fed to an amplifier 225, where it is amplified. The bias of the amplifier 225 can be controlled by potentiometer 230.
FIG. 23 is a diagram showing an alternate embodiment of the eye movement sensor of the present invention. As discussed earlier, movement of a golfer's [0110] eye 26 can be measured and processed by the present invention during a golfer's stroke. An infrared sensor 230 can be provided for measuring such movement. An emitter 232 provides an infrared beam that travels along path A and strikes a portion of the eye 26. The beam is then reflected back along path B to a sensor 234. The intensity of the beam received by the sensor 234 depends upon the portion of the eye struck by the beam, as different eye portions have different reflective properties. Movement of the eye can thus be discerned from fluctuating reflected intensities sensed by the sensor 230.
In a preferred embodiment of the present invention, the [0111] sensor 230 is the QRB1133 or QRB1134 reflective object sensor manufactured by FAIRCHILD SEMICONDUCTOR, Inc. The QRB1133/1134 comprises an infrared emitting diode and an NPN silicon phototransistor mounted side-by-side on a converging optical axis in a black plastic housing. The phototransistor responds to radiation fiom the emitting diode when a reflective object passes within its field of view The device has a high sensitivity, and has an area of optimum response that approximates a circle of 0.200 inches in diameter. Of course, any suitable infrared motion sensor known in the art could be substituted for sensor 230 without departing from the spirit or scope of the present invention.
FIG.24[0112] a is a block diagram showing a circuit, indicated generally at 250, for producing a combined serial data stream containing eye, club, and head movement data. A first controller 252 receives eye and head movement signals that have been converted from analog to digital format by A/D converters. A second controller 256 receives clubhead movement data that has also been converted from analog to digital format by an A/D converter. The first controller 252 produces a serial data stream comprising both eye and head movement data, and forwards the stream to a first transceiver 254. The second controller 256 produces a second serial data stream comprising clubhead movement data, and forwards same to a second transceiver 258. The first transceiver 254 produces a word code, illustratively indicated as word code Z, and selectively transmits same to transceiver 258. The word code Z initiates the data stream generated by the second controller 256, such that the second serial data stream generated by the second controller 256 is synchronized with the first serial data stream generated by the first controller 252.
Both the [0113] first transceiver 254 and the second transceiver 258 transmit an RF signal that is received remotely by third transceiver 260. The RF signal transmitted by the first transceiver 254 is synchronized with the RF signal transmitted by the second transceiver 258, and contains the first serialized data stream produced by the first controller 252. The second RF signal contains the second serialized data stream generated by the second controller 256. The first and second RF signals received by the third transceiver 260 are combined to form a single serial data stream containing eye, head, and club movement data. Preferably, the single serial data stream is compatible with the RS-232 communications protocol standard, and is sent to a PC for further processing and analysis.
In a preferred embodiment of the present invention, the [0114] controllers 252 and 256 are the T89C51AC2 8-bit microcontroller unit manufactured by AMTEL, Inc. The T89C51AC2 is a high-performance, flash version of the 80C51 single chip 8-bit microcontroller, and includes a 32 Kbyte flash memory block for storing programs and data. The TC89C51AC2 includes a plurality of parallel inputs and a serial output, allowing conversion of data received at the inputs into a serialized data stream at the serial output. Thus, as used herewith, the T89C51AC2 receives at its input ports eye, head, and club movement data, and converts same for transmission as serial data streams. Any suitable microcontroller known in the art can be used as controllers 252 and 256 without departing from the spirit or scope of the present invention. Further, the transceivers 254, 258, and 260 are preferably the TR1000 hybrid transceiver manufactured by RFM, Inc. and discussed earlier with reference to FIGS. 18-19.
FIG. 24[0115] b is a block diagram showing sample data streams produced by the circuit of FIG. 24a. As mentioned previously, the controllers 252 and 256 produce serialized data streams that are synchronized with each other and which contain eye, head, and club movement data. As shown in FIG. 24b, the first data stream represents the first serialized data stream produced by the controller 252 of FIG. 24a. The second data stream represents the second serialized data stream produced by the second controller 256. During operation, the first data stream is initiated by the first controller 252 and transmitted by the first transceiver 254. An identifier word A is transmitted, followed by eye movement data. Then, an identifier word B is transmitted, followed by head movement data. A synchronizing word Z is transmitted, wherein transmission in the first data stream halts. The second data stream is then initiated by the second controller 256 and transmitted by the second transceiver 258. An identifier word C is transmitted, followed by club movement data. The second data stream is then halted, and approximately 5 msec later, transmission of the first data stream resumes, wherein eye and head data is then transmitted in the aforementioned fashion. In this arrangement, the first and second data streams can be received by the third transceiver 260, and combined into a single data stream containing eye, club, and head movement data. While the combination of signals provides an elegant solution, the signals can of course be sent separately.
FIG. 25[0116] a is a schematic showing a circuit, indicated generally at 265, for processing finger, wrist, and elbow acceleration signals. The present invention can be adapted to measure and analyze finger, wrist, and elbow movement information. Such information can be acquired during a golf stroke, or during a free throw, such as when a ball is tossed or thrown. Other types of measurements could be acquired. The circuit 265 comprises an operational amplifier (op amp) 267, to which an acceleration signal is input. The acceleration signal could be acquired by any type of sensor (e.g., optical or electro-mechanical), and could comprise finger, wrist, elbow, or other type of movement data. The amplifier 267 can be biased by a potentiometer 268, and its gain controlled by a fixed resistor 269 or other means. The acceleration signal is thus amplified by amplifier 267, producing an output acceleration signal that can be processed in accordance with the present invention.
FIG. 25[0117] b is a block diagram showing a circuit, indicated generally at 270,for producing a combined serial data stream containing eye, finger, wrist, and elbow acceleration data. As discussed earlier, a single serialized data stream comprising eye, head, and club movement data can be produced by the present invention for analysis by a PC or other similar device. This data stream can be adapted to include serialized eye, finger, wrist, and elbow movement data. Thus, as shown in circuit 270, a plurality of signals, such as eye, finger, wrist, and elbow acceleration/movement data, are fed to a first controller 272. The controller 272 could be the aforementioned T89C51AC2 microcontroller, or other suitable substitute. The movement data is received in parallel by the controller 272, and converted to a serial data stream. The serial data stream is then sent to a first transceiver 274, which could be the aforementioned TR1000 transceiver or other similar substitute. The data stream is then transmitted by the first transceiver 274 via a single RF channel, and received by the second transceiver 276 (which could also be the TR1000 transceiver or suitable substitute). The wireless serial data stream received by the second transceiver 276 is then sent to a PC, where it can be processed by a software integration application and/or analyzed by another application. Conceivably, time traces corresponding to finger, wrist, and elbow movement data could be generated, and compared to predetermined time traces and/or thresholds. It should be noted that the signals corresponding to finger, wrist, and elbow movement need not be serialized prior to transmission, and could be transmitted separately from the device.
FIG. 25[0118] c is a block diagram showing the circuit of FIG. 25b in greater detail. As mentioned earlier, finger, wrist, elbow, and eye movement data can be measured during a free throw. A plurality of accelerometers, indicated generally at 280, in addition to an eye movement sensor 282, can be connected to the controller 272 for acquiring finger, wrist, elbow, and eye movement data during the free throw. Preferably, the accelerometers 280 comprise a finger accelerometer 284, a wrist accelerometer 286, and an elbow accelerometer 288, each of which produce acceleration signals that are fed to the controller 272 for processing in accordance with the present invention. In a preferred embodiment of the present invention, the accelerometers 280 comprise the ADXL202 accelerometer chip manufactured by ANALOG DEVICES, INC., discussed earlier. Of course, any known suitable accelerometer can be substituted without departing from the spirit or scope of the present invention.
FIG. 26[0119] a is a view showing an apparatus according to the present invention for measuring finger, wrist, and elbow movement during a free throw. The apparatus, indicated generally at 300, includes a finger sensor 326, a wrist sensor 320, and an elbow sensor 314, each of which are connected together by cable 310. The cable 310 includes a connector 308 for connecting an external power source to the sensors 314, 320, and 326. Preferably, a battery pack 302 delivers such power, and is interconnected with the sensors via cable 304 and connector 306 a. Output from the sensors is fed to one or more controllers via connector 306 a. Importantly, the cable 310 is flexible, conforms to a wearer's aim in use, and allows the wearer to take a free throw without interfering with same. Optionally, one or more retainers 312, such as straps or other similar retainers, can be connected to cable 310 for retaining the cable 310 against the wearer's arm.
The [0120] elbow sensor 314 comprises a first strap 316, and second strap 317, and a central portion 318 interconnecting the straps. The first strap 316 is positionable about the upper arm of a wearer (e.g., between the shoulder and elbow), and the second strap 317 is positionable about the forearm of the wearer (e.g., between the elbow and wrist). Preferably, the straps 316 and 317 are adjustable to accommodate various arm sizes, and include attachment means, such as hook-and-loop fasteners, for removably securing the sensor 314 about the wearer's elbow area. Further, the central portion 318 is flexible, and allows the straps 316 and 317 to move back and forth. When the straps 316 and 317 are positioned on both the upper arm and forearm of the wearer, respectively, the central portion 318 flexes with elbow movement of the wearer during a free throw. Attached to the central portion 318 is an accelerometer for measuring elbow movement during the free throw. Of course, the accelerometer could be positioned at any suitable location on the elbow sensor 314 for sensing elbow movement.
The [0121] wrist sensor 320 comprises a strap 322 connected to a tab 324. The strap 322 is preferably positioned about the wearer's wrist. When the wearer's wrist moves, the tab 324 also moves. Attached to the tab 324 is an accelerometer for measuring wrist motion during a free throw. Preferably, the strap 322 is adjustable for accommodating wrists of various sizes, and includes a retaining means, such as a hook-and-loop fastener, for allowing the strap to removably secured around the wearer's wrist. During a fee throw, when a wearer's wrist flexes, this motion is transferred to the accelerometer and measured accordingly.
Attached to an end of the [0122] cable 310 is a finger motion sensor 326. Finger motion sensor 326 comprises a rearward portion 328 flexibly or hingedly connected to a forward portion 330. The rearward portion 328 includes a sleeve for allowing insertion of a wearer's finger thereinto. The forward portion 330 includes one or more finger loops, such as loops 332 and 333, for allowing insertion of the wearer's finger thereinto. Optionally, a hinge 329 could be provided for hingedly attaching the rearward portion 328 to the forward portion 330.
The [0123] forward portion 330 includes an accelerometer for measuring finger motion during a flee throw. During use, the finger sensor 326 is retained against the wearer's finger by the loops 322, 333 and sleeve 328. When the wearer's finger flexes, the forward portion 330 pivots with respect to the rearward portion 328 This movement is sensed by the accelerometer, producing measurements corresponding to finger movemement.
It is to be understood that the foregoing description relating to measuring finger, wrist, and elbow movement is not limited to free throw situations. Indeed, the [0124] apparatus 300 could be used to sense any desired movements in any situation. For example, finger, wrist, and elbow movement could be sensed during an exercise routine to determine optimal exercise positions. Further, any number of accelerometers could be positioned anywhere along the arm for measuring movemement. The information acquired can be transmitted individually, or serialized according to the present invention and transmitted as a single data stream. Moreover, the acquired information can be transmitted wirelessly, and other sensors, such as potentiometers, could be employed without departing from the spirit or scope of the present invention.
FIG. 26[0125] b is a view showing the apparatus of FIG. 26a in use during a basketball throw. In this situation, the elbow sensor 314, wrist sensor 320, and finger sensor 326 are securely positioned against a wearer's arm, and measure finger, wrist, and elbow movement as the wearer throws the basketball 340. The elbow sensor 314 is held in position via the straps 316 and 317, which are preferably positioned about the upper arm 342 and forearm 346 of the wearer, respectively. The wrist sensor 320 is held in position via the strap 322, which is preferably positioned about the wearer's wrist 348. The finger sensor 326 is held in position via the sleeve 328. Optionally, a belt 303 could be provided for conveniently holding the battery pack 302 in place against the wearer's hip. The cable 310 interconnects the elbow sensor 314, wrist sensor 320, and finger sensor 326. The cable 310 could operate as a power bus, transferring power from the battery pack 302 to each of the sensors, a data bus for culling data fiom each of the sensors, or a combination thereof (e.g., a multi-conductor or ribbon cable could be employed for carrying both power and data signals). The acquired information from the sensor can be transmitted wirelessly or in a wired configuration using a data transfer cable connected to the cable 310. Further, the data from the sensors can be serialized and transmitted as a single data stream, via wire or wirelessly.
FIG. 27[0126] a is a graph showing time traces of finger, wrist, elbow, and eye movements during a free throw. In a preferred embodiment of the present invention, vertical eye movement of the left eye is measured during the free throw, but of course, any type of eye movement from one or both eyes could be measured and analyzed. Additionally, finger, wrist, and elbow movements are also measured and analyzed. Time traces are produced, indicating finger, wrist, elbow, and eye movement and comparing same to predetermined patterns. In the traces, measured movements are indicated by the solid lines, and predetermined patterns of an expert basketball player are indicated via the dotted lines. The time traces thus provide an effective basis of comparison of the user's free throw to that of an expert.
Having thus described the invention in detail, it is to be understood that the foregoing description is not intended to limit the spirit and scope thereof. What is desired to be protected by Letters Patent is set forth in the appended claims. [0127]

Claims

What is claimed is:

1. An apparatus for analyzing golf strokes comprising:

a sensor for sending a signal and receiving a reflected signal;

a reflective surface on a golf club head for reflecting the signal from the sensor back to the sensor; and

a transmitter for transmitting the reflected signal to a processor,

wherein the processor produces movement measurements of the golf club head during the golf stroke.

2. The apparatus of claim 1, wherein the signal comprises an infrared signal

3. The apparatus of claim 2, wherein the infrared signal is generated by an infrared LED

4. The apparatus of claim 3, wherein the reflected signal is received by an infrared phototransistor.

5. The apparatus of claim 1, wherein the measurements are compared to measurements of golfers of different skill levels.

6. The apparatus of claim 1, wherein the measurements comprise time traces.

7. The apparatus of claim 1, further comprising a second sensor for sensing head movement of the golfer during the golf stroke.

8. The apparatus of claim 7, wherein the second sensor includes an accelerometer for measuring head movement.

9. The apparatus of claim 7, further comprising a third sensor for sensing eye movement of the golfer during the stroke.

10. The apparatus of claim 9, wherein the third sensor comprises an infrared eye movement detector for sensing movement of the eyes of the golfer during the golf stroke.

11. The apparatus of claim 10, further comprising a controller connected to the first, second, and third sensors for producing a serialized data stream containing golfer movement data measured by the sensors.

12. The apparatus of claim 11, wherein the controller is connected to a transmitter and the transmitter wirelessly transmits the serialized data stream to the processor.

13. An apparatus for analyzing golf strokes comprising:

a first sensor for sensing movement of a golf club head during the golf stroke;

a second sensor for sensing head movement of the golfer during the golf stroke;

a third sensor for sensing eye movement of the golfer during the golf stroke; and

a transmitter for wirelessly transmitting sensed movement of the golfer and the club head to a remote processor, the processor producing measurements corresponding to the movement of the golfer and the club head during the golf stroke.

14. The apparatus of claim 13, wherein the first sensor comprises an infrared ranger.

15. The apparatus of claim 14, wherein the infrared ranger detects club head position and velocity.

16. The apparatus of claim 13, wherein the first sensor produces a signal corresponding to the movement of the putter.

17. The apparatus of claim 16, wherein the signal is sent to the processor for producing the measurements.

18. A method for analyzing golf strokes comprising:

providing a golf club with a reflective back surface;

positioning the transceiver behind the golf glub and along a swing line of the club;

sending signals from the transceiver towards the club;

allowing the golfer to take a stroke;

receiving reflected signals from the reflective back surface of the club during the stroke;

transmitting the received signal to a processor; and

producing measurements at the remote processor corresponding to the movement during the golf stroke.

19. The method of claim 18, further comprising sensing head movements of the golfer during the golf stroke.

20. The method of claim 19, further comprising producing measurements corresponding to the head movements of the golfer during the golf stroke.

21. The method of claim 18, further comprising sensing eye movements of the golfer during the golf stroke.

22. The method of claim 21, further comprising producing measurements corresponding to the eye movements of the golfer during the golf stroke.

23. The method of claim 18, further comprising comparing the measurements of the golfer to measurements of golfers of different skill levels.

24. The method of claim 40, further comprising serializing the sensed data into a single data stream and then wirelessly transmitting the single data stream to the processor.

25. An apparatus for analyzing free throw movements comprising:

a first sensor for sensing finger movement during a free throw;

a second sensor for sensing wrist movement during the free throw;

a third sensor for sensing elbow movement during the free throw; and

a processor connected to the first, second, and third sensors for producing measurements corresponding to the finger, wrist, and elbow movements.

26. The apparatus of claim 25, further comprising a controller connected to the first, second, and third sensors for combining sensed movements into a single data stream.

27. The apparatus of claim 26, wherein the single data stream is transmitted to the processor for processing.

28. The apparatus of claim 26, wherein the single data stream is wirelessly transmitted to the processor for processing.

29. The apparatus of claim 25, further comprising a transmitter for wirelessly transmitting sensed movement to the processor.

30. The apparatus of claim 25, wherein the measurements comprise time traces.

31. The apparatus of claim 25, further comprising a fourth sensor for measuring eye movement during the free throw.

32. The apparatus of claim 31, wherein the fourth sensor measures vertical eye movement of an eye during the free throw.

33. The apparatus of claim 31, wherein sensed eye movements are wirelessly transmitted to the processor.

34. A method for analyzing movement during a free throw comprising:

providing sensors for measuring finger, wrist, and elbow movement;

attaching the sensor to a wearer's finger, wrist, and elbow;

allowing the wearer to take a free throw;

sensing finger, wrist, and elbow movement during the free throw; and

producing measurements corresponding to sensed finger, wrist, and elbow movements.

35. The method of claim 34, further comprising sensing eye movement during the free throw.

36. The method of claim 34, further comprising transmitting sensed movements to a processor for processing.

37. The method of claim 34, wherein the step of producing measurements comprises producing time traces corresponding to sensed finger, wrist, and elbow movements.

38. The method of claim 37, further comprising comparing the time traces to time traces of experts.

39. The method of claim 34, wherein the step of sensing movements comprises sensing finger, wrist, and elbow movement during a basketball throw.

40. The method of claim 34, wherein the step of sensing movements comprises sensing finger, wrist, and elbow movements during a baseball throw.

41. The method of claim 34, wherein the step of sensing movements comprises sensing finger, wrist, and elbow movements during a golf swing.