Fe, E4 7
`
`4, 224,948
`XR
`United States Patent (19)
`Cramer et al.
`
`(11
`(45)
`
`4,224,948
`Sep. 30, 1980
`
`(54) WRIST BORNE PULSE
`METER/CHRONOMETER
`76 Inventors: Frank B. Cramer, 14800 Alexander
`St., Mission Hills, Calif. 91345; J.
`Lawrence Semar, 17422 Village Dr.,
`Tustin, Calif. 92680
`21 Appl. No.: 963,278
`22 Filed:
`Nov. 24, 1978
`51
`Int. Cl. ................................................ A6B 5/02
`52 U.S. C. .................................................... 128/690
`58 Field of Search ................................ 128/687-690,
`128/698, 705-706, 708; 324/78 D, 186;
`364/701-702, 715-717
`References Cited
`U.S. PATENT DOCUMENTS
`4/1974 Orr et al. .............................. 128/690
`3,807,388
`5/1977 Laukien ...
`... 128/706
`4,022,192
`7/1977 Bloom ............................... 324/78 D
`4,034,745
`4,063,551 12/ 1977 Sweeney .............................. 28/690
`
`56
`
`s 4,093,850 6/978 Karnowski et al. ................. 364/70
`4,096,854
`6/1978
`Perica et al. ......................... 128/690
`4,163,447
`8/1979 Orr ....................................... 128/690
`Primary Examiner-Robert W. Michell
`Assistant Examiner-Francis J. Jaworski
`Attorney, Agent, or Firm--John E. Wagner
`57
`ABSTRACT
`A combined watch, elapsed time counter and pulse rate
`meter which is totally portable and worn as an ordinary
`wristwatch. The timer and pulse rate meter employ the
`precise timing elements such as a crystal oscillator of
`the digital watch. Using such precise timing elements,
`the human's pulse may be measured on a pulse by pulse
`basis and the instantaneous and average pulse values
`simultaneously displayed to allow a running compari
`son and noting of pulse aberrations. A novel pulse de
`tector assembly is located on the inner face of the watch
`assembly.
`
`15 Claims, 9 Drawing Figures
`
`N .
`
`
`
`1
`
`APPLE 1010
`
`

`

`
`U.S. Patent—Sep. 30, 1980 Sheet 1 of 3 4,224,948
`
`U.S. Patent Sep. 30, 1980
`Sheet 1 of 3
`4,224,948
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`N
`r
`XS X
`SY
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` \S
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`44 is
`Cli=
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`2
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`

`

`U.S. Patent Sep. 30, 1980
`
`Sheet 2 of 3
`
`4,224,948
`
`FG. 7
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`22 HZ
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`8.
`16
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`DVDE
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`167
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`... 2 Hz.
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`21
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`
`
`ADDER
`
`coe
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`
`. .
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`. .
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`. . . .
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`.
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`6
`16
`
`N-3 PULSE
`
`RATE
`
`i.
`
`COUNTER
`TRANSFER &
`RESET LOGIC
`
`PULSE
`RATE
`
`N- PULSE
`RATE
`
`N" PERIOD
`COUNTER
`
`LAST FEROD
`COUNT
`REGISTER
`
`(N1)"PERIOD
`COUNTER
`
`|N" PULSE
`RATE
`
`172
`
`161
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`
`
`REGISTER
`
`171
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`21
`2' HZ
`
`-
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`9
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`COUNTER
`
`
`
`DVDER
`
`COUNTER
`REGISTER
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`3
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`

`

`U.S. Patent sep. 30, 1980
`
`sheet 3 of 3
`
`4.224,948
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`
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`1OO
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`CRYSTAL
`9SC.
`2' HZ
`
`
`
`
`
`2'Hz
`
`
`
`1O2
`CONVERTER
`
`2 HZ
`
`2NHz STROBE
`AND
`DIGIT
`DRIVER
`
`113
`
`FIG. 8
`
`SEGMENT
`DECODER
`AND
`DRIVER
`114
`
`112
`
`MULTIPLEXER
`
`DVDE
`BY 1O
`
`OO1 SEC I SECONDS
`COUNTER
`OUNTER
`C
`
`
`
`1O3
`
`1O4
`
`
`
`
`
`MINUTES
`COUNTER
`
`HOURS
`COUNTER
`
`DAYS
`COUNTER
`
`DATE
`COUNTER
`
`SET
`LOGIC
`11O
`
`SET & DISPLA
`LOGIC
`
`111
`
`L l
`
`Y
`
`Y.
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`2.
`O oh
`DATE/TIMEGE
`ti- O 539
`PULSE (
`l
`5 33
`TIMER GEO
`g
`
`-
`l
`
`8 HZ
`
`FREOUENCY
`STEERING
`
`O
`TEST INPUT
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`
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`169
`RUNNING
`AVERAGE
`4 PULSES
`
`172
`
`171
`
`4
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`

`

`1.
`
`WRIST BORNE PULSE METER/CHRONOMETER
`
`BACKGROUND OF THE INVENTION
`For many years both health care professionals and s
`athletic coaches have recognized that the pulse rate of
`an individual is a primary source of information about
`the current and long-term condition of a person's physi
`ology. To the health care professional the measurement
`of pulse rate is a primary measurement taken at the O
`outset of an examination and is a parameter which is
`measured regularly for continuing diagnosis and care.
`Hospitals are now well equipped for continuous moni
`toring of the pulse rate of patients in cardiac and critical
`care units. To the athletic coach and to the occasional 5
`and regular athlete, the pulse rate of the athlete is im
`portant and hopefully known. In the past attempts have
`been made to produce a portable pulse rate meter which
`can be carried by or worn by the athlete to provide
`current pulse rate information while the athlete is en- 20
`gaged in strenuous activity such as running. Examples
`of patents showing pulse rate meters to be worn or
`carried by individuals are U.S. Pat. Nos. 3,978,849 to
`Harold S. Geneen, 4,009,708 to John J. Fay, Jr.,
`4,058,118 to Lawrence J. Stupay et al, 4,030,483 to Jack 25
`B. Stevens, 4,063,551 to James Sweeney, and 4,038,976
`to Frank M. Hardy et al.,
`Numerous other patents have issued to inventors of
`complex pulse rate meters designed for non-portable
`hospital and other fixed installation use. Examples of 30
`such equipment are shown in U.S. Pat. Nos. 4,022, 192
`to Laukren and 4,018,219 to Hajaiban.
`Numerous patents have issued on digital watches and
`various timing and display circuitry therefor.
`Nowhere in the prior art has it been recognized that 35
`by combining a pulse rate meter with a digital watch, in
`addition to the normal advantages one might expect, the
`resulting instrument has greater contribution than the
`sum of its parts. It is believed that in the prior art no one
`has combined a watch giving real time with a pulse-rate 40
`meter. And more particularly, no one has used such a
`combination in which the precise accurate timing cir
`cuitry of the watch is used to provide both timing for
`the signal processing and display of pulse information.
`The additional accuracy possible allows the display of 45
`instantaneous pulse rate on a pulse by pulse basis unrec
`ognized in the prior art. Further, the prior art does not
`recognize that by the simultaneous display of average
`and instantaneous values of the wearer's pulse rate, the
`comparison between instantaneous and average pulse 50
`rate may be accomplished to give a direct indication of
`abnormalities, and the exact time of the abnormality
`occurrence may be observed.
`BRIEF DESCRIPTION OF THE INVENTION
`We have discovered that greatly enhanced utility for
`wrist-borne pulse rate meters is possible by combining
`the available technology in digital watches with im
`proved signal processing to detect the actual instanta
`neous pulse rate of the wearer on a pulse by pulse basis, 60
`and to simultaneously calculate and display the average
`ulse rate over a period of time equal to "N' pulses.
`Thus employing our invention the wearer is able to
`simultaneously observe his average pulse rate and the
`last pulse rate. This allows the wearer to follow the 65
`cardiac response to changing work loads and to detect
`abnormalities in his pulse rate which otherwise would
`be Submerged in averaging type circuitry. A simulta
`
`4,224,948
`2
`neous display of average and instantaneous pulse rate
`may show a difference between the two which is of no
`significance, for example by movement of the sensor on
`the skin or other external interference. On the other
`hand the display of instantaneous rate may indicate the
`existence of premature ventrical contractions of the
`heart requiring the attention of the wearer's physician.
`The availability of actual time data allows the wearer to
`know when deviations occurred and this can be cali
`brated with the nature of his activity, the extent of
`exertion and physical location if later desired. In accor
`dance with our invention there is the elimination of
`ambiguity present in many of the types of digital dis
`plays where the common field is used to display sequen
`tially data of a different nature requiring the user to first
`ascertain what data is being displayed followed by an
`observation and analysis of the data. The data may have
`changed between the time that the first appraisal is
`made and the second observation, resulting in a confus
`ing situation.
`In accordance with this invention a device which has
`the general appearance of a digital watch is employed.
`On the outer face there are a pair of windows. One
`window displays real time in accordance with common
`practice for digital watches. The second window, hav
`ing six digits for data presentation, allocates three
`spaces to average pulse value and three spaces to the
`instantaneous pulse value. Selector switches, one for the
`time record, and the other for the pulse display, are
`located in the edge of the watch case for easy access.
`They are of different shape and location to allow tactile
`identification.
`The under face of the case includes a pulse trans
`ducer. In one embodiment the pulse transducer is an
`electro-mechanical device such as a piezoelectric crys
`tal. When the transducer is an electro-mechanical de
`vice, the watch must be worn on the volar surface of the
`wrist but lateral to the tendon cord bundles. In the sub
`pollex depression, the pulse of the radial artery may be
`obtained. The ulnar pulse may be obtained on the oppo
`site side of the tendon cord bundle from the radial ar
`tery.
`In the preferred embodiment the pulse transducer is a
`light source such as an LED centrally located and en
`circled by a light detector such as a photo diode. A pair
`of light blocking rings integral with a lower case face
`isolate the photo detector from direct view from the
`light source and from view of the ambient light when
`the lower face is in contact with the wearer's body e.g.
`the wrist. In the employment of the light backscatter
`sensing described above, the watch is worn on the lat
`eral surface of the wrist so that the sensors can respond
`to the pulse induced changes in the arteriolar and capil
`lary beds in the subcutaneous tissues.
`The circuitry accomplishing the improved results of
`this invention employs a common oscillator which is
`used to drive both the timing circuitry and display cir
`cuitry. The timing circuitry for the watch constitutes
`well known dividers, counters, a multiplexer and driv
`ing circuitry. The display similarly is one of the well
`known types of LED or liquid crystal. This display is
`commonly found in watches of the digital type.
`The pulse signal processing circuitry of this invention
`is driven by the same oscillator used in the watch timing
`functions and includes a circuitry for developing a trig
`ger signal for each pulse of the wearer and for convert
`ing the train of clock beats into a stored frequency
`
`55
`
`4.
`
`5
`
`

`

`5
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`10
`
`15
`
`20
`
`35
`
`45
`
`Watch .
`
`Function
`Switch Date or time
`15
`selection
`
`Pulse
`Rate
`
`Switch Pulse Sensor and
`16
`Display Condition
`
`50
`
`4,224,948
`4.
`3
`In FIG. 1 the time is registered as 7 hours, 30 minutes
`count in pulses per minute. The last read pulse rate is
`and 0 seconds while a typical pulse rate for one engaged
`stored and the values of the last "N" pulse rates are
`in athletic activity is displayed in the lower window 14.
`stored. The last pulse rate is displayed via the multi
`The instrument 10 registers an average rate of 122
`plexer and display. The average of the last "N" rates is
`pulses per minute with an instantaneous or last pulse at
`determined via a divide by "N' circuit and is likewise
`displayed via the multiplexer and the display.
`a rate of 119 pulses per minute.
`In addition to the desirability of dual independent
`Where six digits of time information are desired for
`example, hour, minutes and seconds, six-digit display is
`space for time and pulse information, simultaneous dis
`used for time. Employing this invention six digits are
`play of average pulse rates and instantaneous pulse rate
`required for a display of average and instantaneous
`is of significant importance. Prior art pulse rate meters
`pulse rates. Thus two identical six-digit displays are
`using less precise circuitry employ averaging to avoid
`employed in this invention. The time functions are pres
`displaying an abnormality related to either patient
`ented in a 3x2 digital display and the pulse rates are
`movement relative to the transducer or errors in signal
`presented in a 2X3 digital display.
`processing. In accordance with this invention, the si
`A novel infra-red source-detector combination is
`multaneous display of average and instantaneous pulse
`disclosed employing a concentric arrangement of light
`rate provides three important sets of information; the
`source and detector and light blocking bosses surround
`two values displayed plus the simultaneous comparson
`ing each.
`of the two. The average pulse rate is important in show
`ing the trend over a number of cycles and will tend to
`BRIEF DESCRIPTION OF THE DRAWING
`change less dramatically. Thus a jogger can watch his
`FIG. 1 is a front face view of the combined digital
`pulse climb from start of activity towards the limit he or
`watch and pulse rate meter of this invention with the
`his doctor has set.
`straps shown in fragmentary form;
`Any abnormality in any one pulse is clearly displayed
`FIG. 2 is a rear view of the invention of FIG. 1;
`in the right three digits of the pulse rate display. Its
`FIG. 3 is a side elevational view thereof;
`25
`displacement from the average rate indicates the abnor
`FIG. 4 is a rear face view of an alternate embodiment
`mality to the wearer at the same instant he is observing
`of this invention;
`the average rate. The abnormality may indicate a pre
`FIG. 5 is a side elevational view of the alternate em
`mature ventricular contraction of the heart about which
`bodiment of FIG. 4;
`the wearer should be concerned based upon his doctor's
`30
`FIG. 6 is a fragmentary sectional view of the sensor
`evaluation, or it may be due to some abnormality of
`portion of the embodiment of FIGS. 1 through 3 taken
`movement of the watch on the wrist or due to some
`along line 6-6 of FIG. 2;
`abrupt change in the activity of the user.
`FIGS. 7 and 8 constitute a block diagram of the cir
`Thus, the average value and the instantaneous value
`cuitry of this invention; and
`both bear significant information and the comparison of
`FIG. 9 is a layout diagram for FIGS. 7 and 8.
`the two values made possible by this simultaneous dis
`DETAILED DESCRIPTION OF THE
`play in the same window provides additional significant
`INVENTION
`information to the wearer. The time display is simulta
`neously available. Thus, time of occurrence is observ
`This invention is embodied in a combination wrist
`watch pulse rate meter in the form best seen in FIG. 1.
`able as well.
`There, the combination of this invention generally des
`The combination of this invention preferably includes
`ignated 10 is all enclosed within a watch type case 11
`three controls-15, 16, and 17 as follows:
`having a front face region 12 with a pair of windows 3
`and 14. Each of the windows 13 and 14 contain display
`means, for example, LED, liquid crystal, or other type
`of visual display commonly used in digital watches. In
`- the preferred embodiment each have a six-digit display
`which may be similar for purposes of minimization of
`types of parts utilized in the manufacture. Since it is
`preferred that the time display has multiple selectable
`time displays-typical labeling under the time displays
`is as disclosed. The time functions preferred to be avail
`able on demand include:
`Date-Day and hour
`Hours, Minutes, Seconds and elapsed time
`Minutes, Seconds, 0.01 seconds.
`In the window 14 again a six-digit display is used but
`in this case the first three digits display the average
`pulse rate and the legend indicating the average is lo
`cated on the front face 12 below the window 14, more
`60
`particularly below the first three digits space, and the
`last three digits display the instantaneous pulse rate and
`is so identified by legend on the face 12. The use of two
`separate displays is advantageous in that it presents the
`actual time of the reading and less confusing readout,
`particularly for the jogger or one who is wearing this
`invention for medical reasons, Time always appears in
`one window and pulse rate in the other.
`
`The timer function is useful particularly for one doing
`timed exercises or jogging but is not mandatory. It
`employs the accurate timing circuitry of the watch and
`uses its display as well. To aid in eliminating any ambi
`guity in the nature of the reading, the timer switch 17
`further produces the display of a decimal point ahead of
`the hundredths position. This signal plus the rapid
`change of the last two positions (hundredths of a sec
`
`Positions
`Display off
`Date on
`Time on
`(1) Sensor and
`Display OFF
`(2) Sensor and
`Display ON
`(3) Sensor OFF
`Display locked
`(1) Timer OFF/Reset
`Display OFF
`(2) Timer ON
`Display ON
`(3) Timer OFF
`Display Locked ON
`to fast recording.
`
`Timer or Switch Control Stop
`Stop
`17
`Watch Timer and
`Watch
`Display
`
`55
`
`65
`
`6
`
`

`

`4,224,948
`5
`6
`ond) gives the user a clear indication that the timer
`DESCRIPTION OF THE CIRCUITRY
`fraction is being displayed in the time window 13.
`The circuitry of this invention which provides for the
`Switch 15 will have three fixed positions to select the
`combination of time, average pulse rate and instanta
`time function display mode and pulse mode for setting
`neous pulse rate information is represented in accor
`or adjusting time functions.
`dance with the preferred circuitry as shown in block
`The combination 10 is held on the wearer's body by
`diagram form in-FIGS. 7 and 8.
`a pair of straps 20 and 21 which may be ordinary watch
`Now referring to FIGS. 7 and 8 in conjunction with
`straps in the preferred embodiment of this invention
`FIGS. 1 through 6 for reference, the basic timing ele
`since all powering, sensing and control features of this
`ment of this invention is an oscillator 100, for example a
`invention are contained within the case 11.
`crystal oscillator operating at a suitable frequency, for
`Now referring to FIGS. 2-5, which are side and
`example 221 Hz. There are precision oscillator crystals
`under side views of the invention of FIG. 1, the typical
`mass produced for watch circuits with nominal frequen
`relationship of the straps 20 and 21 to the case 11 are
`cies of 215 Hz and at 216 Hz, The 215 Hz is too slow for
`more clearly apparent, and in these views the trans- 15
`both precision timing and computation storage and and
`ducer portion on the underside of the case 11 may be
`is based upon every pulse period. The 216 Hz is mar
`seen. This transducer structure is contained within a
`ginal. The 221 Hz is also a mass produced, precision
`boss region 22 of substantial diameter in order to pro
`crystal which may be economically employed. At this
`vide a relatively large area of intimate contact with the
`frequency there is ample speed to execute all of the
`timing, storage, computational, transfer and display
`user's wrist. This will insure both comfortable wearing 20
`and sufficient contact for obtaining an accurate pulse
`functions. The output of the oscillator 100 is introduced
`indication by either a pulse transducer of the pressure
`into the cascaded divider network 101 constituting a
`plurality of divider steps so arranged to provide sub
`type contained therein shown in FIGS. 4 and 5, or by .
`multiples of the basic frequency. Typical frequencies of
`the preferred embodiment employing an infra-red
`the divider 101 used are 210 Hz used to control the
`source-detector combination as best shown in FIG. 2. 25
`' chronometric measurements, 23 Hz used to control fre
`Watch straps must provide adjustable tension in as
`quency steering logic and display logic; 29 Hz for use in
`much as the sensors must be forced into the flesh of the
`the pulse signal acquisition and processing circuit and
`wrist for a reading. This situation may be uncomfort
`22 Hz used in the processing storage and computing of
`able over a prolonged period of time and the strap may so pulse-rates.
`include provision for release of pressure during normal
`The 210Hz signal from the divider 101 is itself intro
`wearing.
`duced in two series connected converters or dividers
`A suitable detector is the type CLT 260 photo diode
`102 and 103; the former, converting the 210Hz signal to
`produced by Clairex Electronics, Inc., of Mount Ver
`the train of pulses of one millisecond duration, and the
`non, New York 10550.
`divider 103 providing 0.01 second timing pulses which
`Centrally located within the detector 23 is a second
`are used to drive a hundredth of a second counter 104.
`ary boss 22A, and an infra-red source 24 which may, for
`The 0.01 second counter 104 is in actuality two cas
`example, be a light emitting diode such as type SSL 55
`caded decade counters: Upon overflow after a count of
`CF of the General Electric Company, which provides
`99 this counter 104 automatically resets to a count of 00.
`emissions in the near infra-red region.
`The seconds counter 105 is actually two decade
`The circular detector array 23 surrounding the infra
`counters set to overflow and reset to 00 after reaching a
`red source 24 insures a detection of the change in opti
`count of 59. At each overflow and reset a pulse is sent
`cal backscatter of the subcutaneous arteriolar and capil
`to the minutes counter 106. Thus counter 104 produces
`an output pulse to a seconds counter 105 every 100
`lary bed of the wearer with each heart contraction and
`pulses constituting one second. The seconds counter
`resultant pulse of oxygenated blood. The boss 22 serves 45
`105 in turn produces one output pulse to a minutes
`to isolate the infra-red detector from ambient light. The
`counter 106 every sixty seconds. The second counter
`boss 22A prevents direct transmission of light between
`105 is actually two decade counters set to overflow and
`source 24 and detectors 23. The coaxial arrangement of
`reset to 00 after reaching a count of 59. At each over
`these three elements provides a relatively large contact
`flow and reset, a pulse is sent to the minutes counter
`surface area resulting in not only effective sensing of a
`106. The minutes counter in turn produces an output
`pulse rate but minimum discomfort to the wearer. The
`pulse each sixty counts to an hours counter 107. The
`circular array of the detector 23 allows the detection of
`hours counter 107 produces a single output pulse to a
`pulses in a substantial arteriolar-capillary bed within the
`day counter 108 once each 24 hours. The day counter
`hemispherical region denoted in FIG. 6 for increased
`108 in turn produces an output pulse for each pulse, and
`signal to noise ratio and energy utilization. In FIG. 3 in
`this latter pulse is introduced into the date counter 109
`partial cross-section, two sections of a single circular
`which in turn provides output pulses once each day to
`apertured disc photo-detector, 23a, are shown. The
`the multiplexer 112. The display elements must be pres
`single photo-detector 23a, or the circular array 23 of
`ented at a rate faster than the normal human flicker
`FIG. 2 allows integration of the backscatter field which 60
`perception which is approximately 16 Hz, or 2 Hz.
`serves the dual purpose of increasing signal sensitivity
`Digital displays at 64 Hz are perceived as a steady
`and reducing position dependence of the pulse meter.
`source. Strobe pulses for the multiplexer 112 are pro
`An alternate, less preferred transducer is illustrated in
`vided by a 2n Hz strobe and digit driver circuit 113
`FIGS. 4 and 5. There boss 32, similar to boss 22, is
`which is additionally connected to a strobe source for
`present however, a pressure transducer 33 constitutes 65
`the display if required. The multiplexer 112 provides the
`the pulse source in direct contact with the wrist of the
`output of the stored information introduced by each
`wearer. The transducer 32 may be of the piezoelectric
`time function source from 1/100th seconds through the
`or other type well known in the art.
`date counter to the segment decoder and segment
`
`7
`
`

`

`15
`
`4,224,948
`7
`8
`driver circuit 114 which is directly connected to the
`is itself under the control of flip-flop 153. As each
`counter is loaded via its respective AND gate and the
`date time display in windows 114 in FIG. 1. Each of the
`foregoing aspects of the chronometry circuitry is well
`flip-flop switches to the opposite state, a dump signal is
`known in the digital watch field and a mre complete
`received from the transferred logic circuit 156 followed
`understanding of the selection and operation of such
`by reset applied to that particular counter. The count in
`circuitry may be had by reference to a number of prior
`each counter is sequentially introduced into the last
`patents or publications but particularly the article enti
`period counter register-157, itself controlled by the
`tled "An I2L Watch Chip with Direct LED Drive'
`logic circuit 156. The count in register 157 is introduced
`article entitled ("An I Watch Chip with Direct LED
`into a divider 159 immediately before reloading. In the
`Drive') appearing in the Journal of Solid State Cir
`divider 159, the count present in the register 157 is
`10
`cuits, Vol. SC-11 No. 6, December 1976 at Page 847 et
`divided into the constant 60X29 from counter 168. The
`seq by Patrick A. Tucci and Louis K. Russell,
`output of the divider 159 is the rate in pulses per minute.
`It is introduced into counter register 160 and in turn
`PULSE METER
`introduced into last pulse rate register 161 where the
`The pulse measuring portions of this invention are all
`last pulse rate in pulse per minute is temporarily stored.
`driven by the same basic oscillator 100 which drives the
`Output lead 171 from the register 161 is used to convey
`chronometric system. The basic timing frequency from
`that last pulse rate signal to multiplexer 112 where it is
`the crystal oscillator 100 has been divided into sub-mull
`in turn applied to the instantaneous pulse display. In
`tiple frequencies 29Hz, 211 Hz, and 221 Hz in the divider
`addition to the register 161, there are four storage regis
`101 and are used in the pulse signal portions of the
`ters 163 through 166, each of which store the last four
`sequential pulse rates with the transfer of pulse rates
`invention.
`Signal acquisition employing our preferred embodi
`between the stages 16i through 166 under the control of
`ment is accomplished in the block identified as 150,
`shift logic circuit 162. The total number of pulses in the
`Signal Acquisition. It includes the infra-red signal
`registers 163 through 166 is obtained in adder 167. By
`dividing by 22 in divider 168, the number of storage
`source 24 which optionally, in order to save power,
`25
`may be pulsed under the control of a pulse power
`registers 163 through ió7, the average pulse rate for the
`source, 24A. Typically, a duty cycle of 20 percent is
`last four pulses is obtained and introduced via lead 172
`after passing through an average count register 169.
`suitable at a pulse rate of 2 KHz.
`The running average on lead 172 is also introduced into
`The infra-red detector 23 will detect the backscatter
`signal emanating from the wrist of the body portion of 30
`the multiplexer 112 for display in the average pulse
`position digits of display 14 of FIG. 1.
`the wearer in the form of a 2 KHz signal modulated in
`amplitude at the pulse rate of the individual. This signal
`What is claimed is:
`is then passed through a suitable amplifier having gain,
`1. A combined digital watch and pulse rate meter
`comprising:
`for example of 1000, and through a band pass filter BPF
`typically having a pass band of 1000 Hz centered at 2
`a case having an upper face and a lower face;
`35
`the upper face including display means for display in
`KHz. The signal is then envelope detected in a suitable
`detector to provide the pulse wave and filtered through
`digital form time of any information;
`said display further including means for displaying
`a low pass filter having a cutoff in the order of 10 Hz to
`eliminate such interference as 60 cycle hum or other
`the six digits of pulse information;
`higher frequency signals that might be picked up. The
`a timing signal generator within said case;
`timing circuitry coupled to said timing signal genera
`detected filtered pulse signal is then introduced into
`signal conversion circuit 152 which typically includes a
`tor for deriving fractions of seconds, seconds and
`pulse square and inverter to provide an output square
`minutes information;
`wave at the frequency of the wearer's pulse. This signal
`means for displaying said time information on said
`display;
`is then introduced as the switching signal to a bi-stable
`45
`multivibrator 153 having a pair of AND gates, each
`a transducer on the inner face of said case positiona
`having one input coupled to output leads of opposite
`ble in pulse sensing relationship with the wearer;
`said transducer coupled to signal processing circuitry
`states of the multivibrator 153. The second input to each
`AND gate is a timing signal at a 29Hz frequency. Each
`for deriving the pulse rate of the wearer;
`of these AND gates will pass the 29 Hz signals to their
`said signal processing circuitry coupled to said timing
`50
`respective counter 154 and 155 for the period that the
`signal generator to provide a time base for pulse
`measurement accuracy equal to the accuracy of the
`multivibrator i53 is in an ON state associated with that
`time of day signal;
`particular AND gate. The counter 154 termed the Nth
`period counter, stores the number of 29Hz pulses which
`means for coupling pulse information from said signal
`pass through its associated AND gate. Similarly, the
`processing circuitry to three digits of said display
`55
`counter 155 which is identified as Nth -- 1 period
`on a pulse by pulse basis to provide instantaneous
`counter, stores the number of 2N Hz pulses passing
`pulse rate display;
`through its associated AND gate when enabled. When
`means for storing the last "N" pulse rates detected;
`there is no change in the pulse rate between two succes
`means for averaging the last 'N' pulse rates stored;
`sive individual pulses of the wearer, the count in both
`and
`60
`counters 154 and 155 will be identical. As the pulse rate
`means for coupling the average pulse rate to the last
`of the wearer changes, the count in the counters 154 and
`set of three digits of said display whereby the pulse
`155 will each change accordingly. The change from
`rate average is displayed for the wearer.
`pulse rate from counter period to counter period re
`2. The combination in accordance with claim 1
`flects the wearer's change in pulse rate on a per pulse
`wherein said display means comprise a pair of six digit
`65
`decimal displays whereby time and pulse information
`basis.
`may be simultaneously displayed for continuous com
`Both the counters 154 and 155 are under the control
`of a counter transfer and reset logic circuit 156, which
`parison by the wearer.
`
`8
`
`

`

`user;
`
`o
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`4,224,948
`9
`10
`3. The combination in accordance with claim 2
`means holding one side of said case against the wear
`wherein said pulse rate display is controlled and enabled
`ers body;
`by a single switch means whereby average and instanta
`said case enclosing
`neous pulse rate values are simultaneously displayed.
`(a) a timing signal source;
`(b) a sensor in pulse sensing relationship with the
`4. The combination in accordance with claim 1
`wearer for producing an electrical signal for each
`wherein "N' is four.
`5. A combined digital watch and pulse rate meter
`pulse of the user;
`comprising:
`(c) means for converting the pulse rate of the user
`a case having an upper and a lower face;
`into a train of timing signals, the number of which
`the upper face including digital display means for
`define the pulse period for each pulse period of the
`displaying time information;
`(d) two counting means;
`said display means including means for displaying six
`(e) means coupling trains of timing signals in alternate
`digits of pulse information;
`sequential order to said two counting means;
`a timing signal generator within said case;
`(f) a register;
`timing circuitry coupled to said timing signal genera
`(g) control means for alternately introducing the
`tor for deriving fraction of seconds, seconds and
`count of said two counting means into said register
`minutes information;
`and for resetting said counting means;
`means for displaying said time information on said
`display;
`(h) means for converting the count from said register
`into the wearer's pulse rate;
`a transducer on the inner face of said case positiona
`(i) a display means on an outer wall of said case;
`ble in pulse sensing relationship with the wearer;
`1 (j) means for applying the output of said converting
`said transducer coupled to signal processing circuitry
`means to said display to display the user's pulse rate
`for deriving the pulse rate of the wearer;
`for th