(12) United States Patent
`Pyles
`
`US006434212B2
`(16) Patent N0.2
`US 6,434,212 B2
`(45) Date of Patent:
`Aug. 13, 2002
`
`(54) PEDOMETER
`
`(76) Inventor: Nathan Pyles, 529 College St., Lake
`Mills, WI (Us) 53551
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`.
`.
`patent is extended or adJusted under 35
`U-S-C- 154(k)) by 0 days-
`
`(21) Appl. No.: 09/756,647
`
`(22) Filed:
`
`Jan. 4, 2001
`
`Related US. Application Data
`
`(63) Continuation of application No. 09/181,738, ?led on Oct.
`28, 1998, now Pat. NO. 6,175,608.
`
`8/1988 Gerhaeuser et 81.
`4,763,287 A
`9/1988 Cavanaugh
`4,771,394 A
`3/1989 Ratlla?
`4,814,661 A
`4/1989 Potsch
`4,821,218 A
`5/1989 Thornton
`4,830,021 A
`7/1989 Rfxlgers
`4’848’OO9 A
`8/1989 Bianco
`4,855,942 A
`9/199O Furlong
`4956 628 A
`4,962,469 A 10/1990 Ono et 81.
`5,033,013 A
`7/1991 Kato et a1.
`5,065,414 A 11/1991 Endou et 81.
`5,117,444 A
`5/1992 Sutton et a1.
`5,164,967 A 11/1992 Endo 6161.
`5,188,447 A
`2/1993 Chiang
`5,285,586 A
`2/1994 Goldston
`5,335,664 A
`8/1994 Nagashima
`_
`_
`(Llst Con?rmed 0n mm Page)
`
`(51) Int. Cl.7 .............................................. .. G01C 21/00
`
`FOREIGN PATENT DOCUMENTS
`
`(52) US. Cl. .................................................... .. 377/242
`(58) Field of Search ....................................... .. 377/242
`
`EP
`
`0 119 009 A1
`
`9/1984
`
`(56)
`
`References Cited
`
`US. PATENT DOCUMENTS
`4,053,755 A 10/1977 Sherri“
`4,144,568 A
`3/1979 Hiller et aL
`4,192,000 A
`3/1980 Lipsey
`4,220,996 A
`9/1980 Searcy
`4,223,211 A
`9/1980 Allsen et a1.
`4,334,190 A
`6/1982 Sochaczevski
`4,337,529 A
`6/1982 Morokawa
`4,367,752 A
`1/1983 JimineZ
`4,371,945 A
`2/1983 Karr et 81.
`4,387,437 A
`6/1983 Lowrey et a1.
`4,460,823 A
`7/1984 Ruehlmann
`4,466,204 A
`8/1984 Wu
`4,499,394 A
`2/1985 Koal
`4,510,704 A
`4/1985 Johnson
`4,560,861 A 12/1985 K910 et 81-
`45667461 A
`1/1986 Lube11_eta1~
`4,578,769 A
`3/1986 Fredenck
`4’649’552 A
`3/1987 Yukawa
`4,651,446 A
`3/1987 Yukawa
`4,703,445 A 10/1987 Dassler
`4,741,001 A
`4/1988 Ma
`
`OTHER PUBLICATIONS
`_
`_
`_
`_
`Form PCT/IPEA/408, Written Opinion received Aug. 8,
`2000, 5 pages,
`Form PCT/ISA/210, International Search Report, 4 pages.
`Sportsline Products, “Fitness Pedometer 360”, Web page, 1
`page
`Sportsline Products, Fitness Pedometer 360 packaging label,
`5 pages_
`
`Primary Examiner—Margaret R. Wambach
`(74) Attorney, Agent, or Firm—Lathrop & Clark LLP
`
`(57)
`
`ABSTRACT
`
`The pedometer having improved accuracy by calculating
`actual stride lengths of a user based on relative stride rates.
`The pedometer includes a Waist or leg mounted stride
`counter, a transmitter for transmitting data to a Wrist
`mounted display unit, and a data processor for calculating
`necessary base units and actual stride rates and lengths. The
`edometer can also interact With a heart monitorin device
`p
`g
`'
`
`8 Claims, 1 Drawing Sheet
`
`48
`
`1
`
`

`

`US 6,434,212 B2
`Page 2
`
`US. PATENT DOCUMENTS
`
`5,361,778
`5,373,651
`5,456,262
`5,457,900
`5,475,725
`5,476,427
`5,485,402
`5,490,816
`5,491,474
`5,500,635
`5,516,334
`5,526,290
`5,539,706
`5,583,776
`
`11/1994
`12/1994
`10/1995
`10/1995
`12/1995
`12/1995
`1/1996
`2/1996
`2/1996
`3/1996
`5/1996
`6/1996
`7/1996
`12/1996
`
`SeitZ
`Wood
`Birnbaum
`Roy
`Nakamura
`Fujima
`Smith et a1.
`Sakumoto
`Suni
`Mott
`Easton
`Kanzaki
`Takenaka
`Levi et 81.
`
`5,611,621
`5,640,786
`5,689,099
`5,720,200
`5,724,265
`5,797,201
`5,891,042
`5,899,963
`5,918,502
`5,945,911
`5,976,083
`6,018,705
`6,175,608
`
`A
`A
`A
`A
`A
`A
`A
`A
`A
`A
`A
`A
`B1
`
`3/1997
`6/1997
`11/1997
`2/1998
`3/1998
`8/1998
`4/1999
`5/1999
`7/1999
`8/1999
`11/1999
`1/2000
`1/2001
`
`Chien
`BuyayeZ
`Domburg
`Anderson
`Hutchings
`Huang
`Sham et a1. .............. .. 600/483
`Hutchings
`Bishop
`Healy
`Richardson et a1.
`Gaudet et a1.
`Pyles et a1.
`
`* cited by examiner
`
`2
`
`

`

`US. Patent
`
`Aug. 13, 2002
`
`US 6,434,212 B2
`
`
`
`3
`
`

`

`US 6,434,212 B2
`
`1
`PEDOMETER
`
`This application is a continuation of application Ser. No.
`09/181,738, ?led Oct. 28, 1998, now US. Pat. No. 6,175,
`608, the disclosure of Which is incorporated by reference
`herein.
`
`FIELD AND BACKGROUND OF THE
`INVENTION
`The present invention relates generally to pedometers
`having a Waist mounted stride-counting device and
`transmitter, and a Wrist-mounted receiver and display. The
`invention also relates to a distance calculation device that
`calculates a distance Walked or run based on an algorithm
`that converts a base stride length and a base stride rate to an
`actual stride length for use in calculating the distance
`traveled.
`Pedometers are knoWn Which include devices or algo
`rithms for determining the distance a person travels on foot.
`For example, US. Pat. No. 4,371,945 discloses an electronic
`pedometer that calculates distance by electronically measur
`ing the length of each stride taken by a user. Stride length is
`measured by ultrasonic Waves generated by an ultrasonic
`module strapped to one leg and an ultrasonic detector Worn
`on the other leg. A program compensates for a variety of
`measurement errors and the results are displayed on a
`Wrist-mounted display after being transmitted by VHF
`Waves from the leg to the Wrist.
`US. Pat. No. 4,771,394 discloses a computer shoe With a
`heel-mounted electronic device With an inertia footstrike
`counter, a timer, a sound generating device, a battery, and a
`gate array for counting time and footstrikes to calculate
`distance and running time as a function of stride time.
`Although recogniZing the important relationship of stride
`length and foot speed, the shoe in this patent requires data
`from at least 15 test runs or Walks and the data must be
`user-entered in pairs of footstrikes and elapsed time to cover
`a pre-determined distance. Further, user adjustments of time
`must be performed to accommodate start and stop times, and
`the number of counted footstrikes is increased one percent to
`overcome inherent errors in the inertia step counter. The
`shoe-mounted device is subject to damage from impact, dirt,
`and Water, and requires a stay-at-home computer With Which
`to interface. There is no means disclosed to transmit data to
`a Wrist-mounted display device or an “on-board” computing
`device that provides “real time” data to a runner.
`US. Pat. No. 4,855,942 discloses a pedometer and calorie
`measuring device that includes a Wrist-mounted step counter
`and a ?xed stride length to calculate distance traveled.
`Wrist-mounted step counters are knoWn to be inaccurate
`because they assume a step for every arm movement. Even
`With error correction, such a device Will provide less accu
`rate step counts than a leg or Waist-mounted counter.
`Further, ?xed stride lengths do not take into account the fact
`that stride length varies With rate of movement.
`US. Pat. No. 5,117,444 discloses a pedometer and cali
`bration method With tWo calibration modes. First, a user
`travels a predetermined “half-distance” for the device to
`count and store the number of strides in that distance. Next,
`the user travels a second distance With the step counter
`comparing actual steps to the steps in memory and a current
`trip memory are incremented by a tenth of a “Whole unit”
`distance. There is no correlation betWeen stride length and
`stride rate Which requires the user to re-calibrate the device
`When Walking as opposed to running.
`US. Pat. No. 5,475,725 discloses a pulse meter With
`pedometer function to determine pace and pulse rate of a
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`user. The meter uses pulse Wave base data compared to
`actual pulse Wave data rates.
`US. Pat. No. 5,476,427 discloses a pace display device
`utiliZing a base rate for traveling pre-set distances in suc
`cessive trails. The device calculates step counts and rates,
`and compares actual step count rates to display data to a user
`for comparison of present running rates to previous rates.
`Thus, there is a need for a simple, but highly accurate,
`pedometer that displays distance traveled, pace, speed, heart
`rate, and other important information on an easily read
`Wrist-mounted device.
`
`SUMMARY OF THE INVENTION
`
`The present invention overcomes problems and shortcom
`ings in the prior art by providing a device that includes a
`Waist, chest, or leg-mounted stride counting device, a
`transmitter, and a Wrist-mounted receiver/display device that
`provides highly accurate travel distances and other informa
`tion. The device includes a computer that stores base stride
`length and rate data from traveling a pre-determined dis
`tance and compares that to actual stride rate data to calculate
`actual distance traveled, speed, and pace. The invention
`recogniZes the interdependency of stride length and stride
`rate and uses that relationship to provide superior distance
`calculating accuracy.
`The invention also provides for improved display of
`relevant data on a Wrist-mounted display that receives digital
`signals from devices Worn on other body parts such as legs,
`Waist, and chest. Transmitters that can send coded signals
`are desirable because they Will not interfere With similar
`devices Worn by other users in the vicinity.
`The accuracy of the device is enhanced by the use of an
`algorithm that adjusts a base stride length based on actual
`stride rates. The algorithm is de?ned as: Actual Stride
`Length=Base Stride Length+Base Stride Length *(((Actual
`Stride Rate-Base Stride Rate) N)/Base Stride Rate); Where
`N is either an average value or a derived value from a
`plurality of samples.
`The invention also includes a method for calculating an
`actual stride length including steps of: timing a ?rst user run
`of a predetermined distance; counting the total number of
`strides in the user ?rst run; dividing the ?rst run distance by
`the stride count to obtain a base stride length; dividing the
`stride count by the ?rst run time to obtain a base stride rate;
`counting strides during a user’s second run to obtain an
`actual stride rate; calculating the actual stride length using
`the formula: Actual Stride Length=Base Stride Length+Base
`Stride Length *(((Actual Stride Rate-Base Stride Rate )N)/
`Base Stride Rate); Wherein N is an average value or a
`derived value.
`The average value method can be re?ned by comparing
`Base Stride Rate to Actual Stride Rate to determine a
`percentage difference; and using N=1 When the Actual Stride
`RateéBase Stride Rate * 1.02 and using N=3 When Actual
`Stride Rate>Base Stride Rate * 1.02. A preferred embodi
`ment uses a plurality of sample runs over knoWn distances
`to derive an accurate N value for each individual.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a schematic diagram of a pedometer in accor
`dance With the present invention.
`
`DETAILED DESCRIPTION OF THE DRAWINGS
`
`As illustrated in FIG. 1, the present invention is directed
`to an improved pedometer 20 including: a Waist, chest, or leg
`
`4
`
`

`

`US 6,434,212 B2
`
`3
`mounted stride counter 24, and a Wrist or Waist mounted
`display unit 26. An optional chest-mounted heart monitor 28
`can be included. All of the device components are mounted
`in suitable housings. The pedometer 20 includes a data
`processor 30 that is mounted in the same housing as either
`the step counter 24 or the display unit 26.
`The step counter 24 is an inertia device that counts the
`number of steps a user takes. The number of steps is
`transmitted to a data archive 32 either directly or via a
`transmitter 34. The data archive 32 is mounted in the
`housing With the step counter 24 or the display 26.
`The transmitter 34 is mounted in the step counter housing
`and is preferably an Rf telemetric signal transmitter With a
`30 inches to 36 inches transmission range. Alternately, the
`transmitter is a Wireless or Wired digital transmitter With a
`coding function to limit or eliminate interference With other
`similar devices. The Wireless transmission range is set
`betWeen 30 inches and 36 inches to provide adequate range
`to transmit signals from a user’s Waist to Wrist, but not so far
`as to cause interference With other Rf or digital devices in
`the vicinity.
`The transmitter 34 transmits either raW data or calculated
`distances, pace, etc. to a Wrist-mounted display unit receiver
`40. The receiver 40 relays a raW data signal to the data
`processor 30 or a calculated data signal directly to the
`display panel 42, such as an LCD or LED.
`Similarly, the heart rate monitor 28 includes a transmitter
`44 that transmits heart rate data to the display unit 26. The
`heart monitor transmitter 44 can transmit at the same or a
`different frequency as the stride counter 24, and to the same
`or a different receiver in the display unit 26. The heart rate
`transmitter 44 is preferably Rf, but can be digital for the
`reasons stated above. The range of the heart rate transmitter
`44 should also be betWeen 30 inches and 36 inches to ensure
`effective communication With the receiver While limiting
`outside interference.
`The data processor 30 can also include a programmable
`logic controller, a personal computer, a programmable read
`only memory, or other suitable processor. The data processor
`30 includes a data archive 32 to store historic data on stride
`length and pace to be used in an algorithm for calculating
`actual distances, speed, and rate for real-time conversion of
`data to useful information for a user.
`The data processor 30 can also include closed loop or
`fuZZy logic programming to continually or periodically
`replace the base stride rate and length With recently calcu
`lated stride rates and lengths so that long term conditioning
`trends are accommodated in the base stride archive. Incor
`porating trend capabilities may further enhance accuracy of
`the distance and pace calculations.
`The display unit 26 also includes an operator interface 46
`such as a key pad, button, knob, etc. that enables the user to
`start and stop a clock 48 (or stop Watch) and activate various
`use modes Within the pedometer, such as a sampling mode
`and operation mode.
`One option for using the pedometer 20, requires the user
`to operate a “sampling mode” and begin Walking or running
`a predetermined distance such as a mile or 1600 meters,
`preferably on a running track of a knoWn siZe. Upon
`completion of the distance, a stop button on the operator
`interface 46 is pushed. The data processor 30 is programmed
`to then divide the distance by the number of strides counted
`to calculate an average stride length. This value is stored in
`the data archive 32 as the “Base Stride Length.”
`Also, the data processor 30 is programmed to divide the
`number of strides by the time of the run or Walk as measured
`by the clock 48 to arrive at a “Base Stride Rate.”
`
`10
`
`15
`
`25
`
`35
`
`45
`
`55
`
`65
`
`4
`The data processor 30 preferably includes programming
`that queries the user about the distance to be run during the
`sampling mode. By providing options or enabling the use of
`any distance during the sampling mode, the pedometer 20
`provides maXimum ?exibility for use by people of various
`physical conditions, or having access to courses of different
`knoWn distances. Thus, a user may be queried to input a
`distance to be used in the sampling mode and then be given
`a list of options such as 400 meters, 440 yards, 1600 meters,
`or one mile, or be asked to simply input any distance knoWn
`to the user that Will be traveled during the sampling mode.
`The present invention makes full use of the relationship
`betWeen a faster rate of travel and longer stride lengths. In
`other Words, the faster a user is moving, the longer Will be
`the stride length. Over the course of the run or Walk, the
`user’s step rate and, therefore, stride length Will change and
`the user Will cover more ground When moving fast and less
`ground When moving sloW.
`Clearly, using a ?xed average stride length in calculating
`distance traveled Will result in errors using prior pedometers.
`This is particularly true if a user changes pace, or improves
`conditioning and speed to the point Where the average stride
`length over a given run increases dramatically. The error
`compensators in prior devices do not adjust for changes in
`pace. With the old devices, a user needed to re-calibrate
`periodically to be close to getting an accurate reading, and
`could not change pace during a Workout Without decreasing
`accuracy.
`To make the correction, the user activates a “Use Mode”
`in Which the data processor 30 calculates an Actual Stride
`Rate based on data from the stride counter 24 and the clock
`48. For eXample, an Actual Stride Rate can be calculated
`every ?ve seconds Without the user doing more than acti
`vating the “Use Mode” button, While all the calculations are
`performed by the data processor automatically. The percent
`age change betWeen the Actual Stride Rate and the Base
`Stride Rate is then computed by the data processor 30 to
`determine an Actual Stride Length. Again, if the Actual
`Stride Rate is greater than the Base Stride Rate, the Actual
`Stride Length is longer than the Base Stride Length. If the
`Actual Steps Per Second is loWer than the Base Steps Per
`Second, the Actual Stride Length is shorter than the Base
`Stride Length. The algorithm beloW provides a means for
`comparing the Actual and Base Stride rates to arrive at an
`accurate Actual Stride Length.
`First, a comparison betWeen the Actual Stride Rate and
`the Base Stride Rate is made to determine Whether Actual
`Stride Rate is less than or equal to Base Stride Rate
`multiplied by 1.02. Stride Length is calculated by:
`
`Actual Stride Length=Base Stride Length+Base Stride Length
`*(((Actual Stride Rate-Base Stride Rate)N)/Base Stride Rate)
`
`Where: N=1 When Actual Stride Rate is less than or equal to
`Base Stride Rate multiplied by 1.02, and N=3 When Actual
`Stride Rate is greater than Base Stride Rate multiplied by
`1.02, although other N values in the range of one to three can
`be used.
`The above algorithm is accurate for heel to toe activities
`such as Walking or jogging, but is less accurate for sprinting
`(toe only).
`A third method of calculating actual stride length uses
`three separate run or Walk samples at three different paces.
`This is the most accurate option. With this method, the N
`values are unique for each individual. By deriving an N
`value for each individual, this value more accurately re?ects
`the actual change in stride length With a change in pace.
`
`5
`
`

`

`US 6,434,212 B2
`
`5
`After a proper Warmup, the user completes a sample run or
`Walk on the track at a normal pace. This ?rst sample S1, Will
`establish the Base Stride and the Base Steps Per Second.
`S1 SAMPLE:
`
`S1 Stride=Base Stride=Distance/Number of Steps
`
`S1 Steps Per Second or S1 Steps Per Second=Base Steps Per Sec
`ond=Number of Steps Per Second
`
`Following completion of the ?rst run or Walk at normal
`pace, the user runs or Walks the same course and the same
`distance at a faster run or Walking pace, but not a sprinting
`pace. The user should not run on his toes, but maintain the
`normal heel to toe jogging style. This is the S2 sample. The
`purpose of the S2 sample is to calculate an N2 value for each
`individual Which re?ects the effect an increase in Steps Per
`Second has on this individual’s stride length. Some indi
`vidual’s steps Will lengthen more than others as Steps Per
`Second increases, and by ?nding the value for N2, this
`relative increase can be quanti?ed for a more accurate and
`customiZed algorithm for each individual.
`S2 SAMPLE:
`
`10
`
`15
`
`To ?nd the N2 value, Which Will be used by the algorithm When
`Actual Steps Per Second>Base Steps Per Second
`
`N2=((S2 Stride * S1 Steps Per Second)—(S1 Stride * S1 Steps Per
`Second))/(S1 Stride (S2 Steps Per Second-S1 Steps Per Sec
`ond))
`
`This value can be calculated since the distance is knoWn,
`and both a Fast Stride Length (S2 Stride) and a Fast Steps
`Per Second (S2 Steps Per Second) can be calculated from the
`second sample.
`FolloWing completion of the fast run or Walk, the user
`runs the same course and the same distance at a sloWer than
`normal run or Walking pace. This pace cannot eXceed the
`?rst sample pace. This is the S3 sample. The purpose of the
`S3 sample is to calculate an N3 value for each individual
`Which re?ects the effect a decrease in Steps Per Second has
`on this individual’s stride length. Some individual’s steps
`Will shorten more than others as Steps Per Second decreases,
`and by ?nding the value for N3, this relative decrease can be
`quanti?ed for a more accurate and customiZed algorithm for
`each individual.
`S3 SAMPLE:
`
`25
`
`35
`
`To ?nd the N3 value, Which Will be used by the algorithm When
`Actual Steps Per Second<Base Steps Per Second.
`
`45
`
`N3=((S3 Stride * S1 Steps Per Second)—(S1 Stride * S1 Steps Per
`Second))/(S1 Stride (S2 Steps Per Second-S1 Steps Per Sec
`ond))
`
`This value can be calculated since the distance is knoWn
`and both a “SloW” Stride Length (S3 Stride) and a “SloW”
`Steps Per Second (S3 Steps Per Second) can be calculated
`from the third sample.
`Once these three samples are completed and the informa
`tion automatically calculated and stored in the data proces
`sor 30, then the folloWing formula can be used for the most
`accurate measurements of speed and distance.
`If:
`
`55
`
`Actual Steps Per Second is less than or equal to Base Steps Per
`Second
`
`Then:
`
`Stride Length=Base Stride+Base Stride*(((Actual Steps Per Sec
`ond-Base Steps Per Second)N)/Base Steps Per Second)
`
`65
`
`And N=N3 (Stored Value)
`
`If:
`
`Actual Steps Per Second>Base Steps Per Second
`
`Then:
`
`Stride Length=Base Stride+Base Stride*(((Actual Steps Per Sec
`ond-Base Steps Per Second)N)/Base Steps Per Second)
`
`And N=N2 (Stored Value)
`
`This third option for calculating stride length, and subse
`quently distance, speed, and pace, is a far more accurate
`method than a ?Xed stride length pedometer. This device and
`method are also practical, convenient, and has a relatively
`loW manufacturing cost. If an individual’s running or Walk
`ing style is progressing With training and practice (as seen by
`signi?cantly improved times), then it may be bene?cial for
`them to recalibrate their device by repeating the three
`samples every 3 to 6 months. If there are no signi?cant
`improvements in time, then recalibration is not necessary.
`It is noted that any single stride length or pace discussed
`above can in fact be an average of a plurality of stride
`lengths or rates from test runs to further re?ne accuracy in
`the calculations of actual stride data.
`Other variations on this device could also incorporate an
`altimeter Which measures changes in elevation. The stride
`length could then be adjusted (shortened) When elevation is
`increasing, and lengthened When elevation is decreasing.
`This adjustment could be done With an average value, as We
`used in setting option 2, or With a derived value by running
`or Walking over a knoWn distance on a hilly course. This
`device can use tWo batteries so that the calibration data is not
`lost When the batteries are replaced one at a time.
`Once the actual stride length is calculated for a given
`period of time, the value can be multiplied by the number of
`strides in that period to obtain a total distance for that period
`to be stored in a data archive ?le for that particular Walk or
`run and added to other actual stride lengths or distances for
`other periods in Which stride length Was calculated. When
`the run or Walk is completed, the user engages the operator
`interface 46 to indicate that a total distance is to be displayed
`on the display unit. Preferably, there is continual display of
`the distance traveled.
`As a result of accurately calculating distance traveled, the
`pedometer 20 also has the capability of calculating speed in
`miles per hour, for eXample or pace in minutes per mile,
`including average speed and pace over the course of that
`particular Walk or run. Further, the pedometer 20 can include
`a port for coupling to a separate personal computer or
`computing device to create larger training histories, trends,
`etc.
`Additional features can include stop Watches, day, date
`and time displays, as Well as, heart rate displays as discussed
`above. Also, it Will be understood that all distances and time
`periods used above can be varied in length and units of
`measure (English, metric, seconds, minutes, hours, etc.).
`The foregoing detailed description is provided for clear
`ness of understanding only and no unnecessary limitations
`therefrom should be read into the folloWing claims.
`What is claimed is:
`1. An exercise monitoring device comprising:
`a strap for releasably securing the exercise monitoring
`device to a user;
`a step counter joined to the strap;
`a heart rate monitor joined to the strap; and
`a data processor programmed to calculate a distance
`traveled by multiplying a number of steps counted by
`
`6
`
`

`

`US 6,434,212 B2
`
`7
`the step counter by a stride length that varies according
`to a rate at Which steps are counted.
`2. An exercise monitoring device comprising:
`a strap for releasably securing the exercise monitoring
`device to a user;
`a step counter joined to the strap;
`a heart rate monitor joined to the strap; and
`a data processor programmed to calculate a distance
`traveled by multiplying a number of steps counted by
`the step counter by a stride length that varies in
`accordance With a stride rate, Wherein the stride length
`is determined With reference to a plurality of calibra
`tions that each calculate a stride length as a function of
`a knoWn stride rate.
`3. The exercise monitoring device of claim 2, Wherein the
`data processor is further programmed to recalibrate the
`stride length as a function of a subsequently calculated and
`knoWn stride rate.
`4. The exercise monitoring device of claim 3, Wherein the
`data processor is further programmed to recalibrate the
`stride length by calculating an average stride length from the
`calibration stride length and the recalibration stride length.
`5. An exercise monitoring device comprising:
`a strap for releasably securing the exercise monitoring
`device to a user;
`a step counter joined to the strap;
`a heart rate monitor joined to the strap; and
`a data processor programmed to calculate a distance
`traveled by multiplying the number of steps counted by
`the step counter by a stride length that varies according
`to the rate at Which steps are counted, and further
`
`10
`
`15
`
`25
`
`8
`programmed to derive the stride length from a range of
`stride lengths calculated from a range of corresponding
`stride rates calculated from a plurality of calibration
`samples.
`6. A pedometer comprising:
`a step counter;
`a transmitter in communication With the step counter to
`generate a step count signal corresponding to each step
`and transmit the step count signal;
`a receiver mountable on a user body portion to receive the
`step count signal transmitted from the transmitter; and
`a data processor programmed to calculate a distance
`traveled by multiplying a number of steps counted by
`a stride length that varies according to a rate at Which
`steps are taken, and further programmed to derive an
`actual stride length from a range of stride lengths
`calculated from a range of corresponding stride rates.
`7. The pedometer of claim 6, Wherein the data processor
`is further programmed to:
`use the range of stride rates to create a corresponding
`range of stride lengths and compare an actual stride rate
`to the range of stride rates to derive a corresponding
`actual stride length.
`8. The pedometer of claim 7, Wherein the data processor
`is further programmed to:
`interpolate betWeen and extrapolate from the ranges of
`stride rates and stride lengths to calculate a plurality of
`additional corresponding stride rates and stride lengths.
`
`7
`
`