US007894888B2
`
`(12) United States Patent
`Chan et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,894,888 B2
`Feb. 22, 2011
`
`(54) DEVICE AND METHOD FOR MEASURING
`THREE-LEAD ECG IN A WRISTWATCH
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`(75) Inventors: Hsiao-Lung Chan, Gueishan Township,
`Taoyuan County (TW); Pei-Kuang
`s
`Chao, Gueishan Township, Taoyuan
`County (TW); Jia-Chen Jheng,
`Gueishan Township, Taoyuan County
`(TW)
`(73) Assignee: Chang Gung University, Taoyuan
`County (TW)
`
`... 600,519
`4,120,294. A * 10/1978 Wolfe ..... ...
`... 600/301
`5,515,858 A * 5/1996 Myllymaki ...
`... 600, 509
`5,613,495 A * 3/1997 Mills et al. .....
`... 600, 509
`6,832,109 B2 * 12/2004 Nissila ......
`... 600, 509
`7,171,259 B2 *
`1/2007 Rytky ............
`2008/0287751 A1* 11/2008 Stivoric et al. .............. 600/301
`* cited by examiner
`Primary Examiner Carl H Layno
`Assistant Examiner Brian T. Gedeon
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 177 days.
`
`(21) Appl. No.: 12/236,558
`1-1.
`(22) Filed:
`
`Sep. 24, 2008
`
`(65)
`
`O
`O
`Prior Publication Data
`US 201O/OO76331 A1
`Mar. 25, 2010
`
`(51) Int. Cl.
`(2006.01)
`A6 IB5/04
`(52) U.S. Cl. ...................................................... 6OOASO9
`(58) Field of Classification Search ................. 600/301
`600/508, 509,485,595
`See application file for complete search history.
`
`
`
`ABSTRACT
`(57)
`A wristwatch worn by a user for measuring a three-lead ECG
`includes three electrodes placed separately on the front, either
`side, and back or strap thereof. The wristwatch further
`includes an electrode panel having the electrode on the front
`or either side of the watch, sensing elements, pressure, infra
`red or impedance detectors, and circuits. The electrode panel
`is capable of sensing the contact or press offingers to trigger
`the ECG measuring. While the electrode in the back-side of
`the watch contacts the hand wearing the watch, the electrode
`and electrode panel on the front or either side of the watch are
`pressed by fingers from the other hand, and the electrode in
`the Strap contacts the abdomen or left leg simultaneously.
`Thus, a three-lead ECG can be measured. ECG data can be
`transmitted to a personal or hospital computer by wireless
`networks or flash memory.
`19 Claims, 14 Drawing Sheets
`
`APPLE 1048
`
`1
`
`

`

`U.S. Patent
`
`Feb. 22, 2011
`
`Sheet 1 of 14
`
`US 7,894,888 B2
`
`
`
`FIG. A
`
`FIG.1B
`
`2
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 2 of 14
`Sheet 2 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`
`
`11
`
`11
`
`FIG.2
`FIG.2
`
`3
`
`

`

`U.S. Patent
`
`Feb. 22, 2011
`
`Sheet 3 of 14
`
`US 7,894,888 B2
`
`21st C
`
`FIG.3A
`
`4
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 4 of 14
`Sheet 4 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`
`
`
`
`FIG.3B
`FIG.38
`
`5
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 5 of 14
`Sheet 5 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`27
`27
`
`'
`)
`
`11
`11
`
`FIG.3C
`FIG.SC
`
`6
`
`

`

`U.S. Patent
`U.S. Patent
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`FIG.3D
`FIG.3D
`
`7
`
`

`

`U.S. Patent
`
`Feb. 22, 2011
`
`Sheet 7 of 14
`
`US 7,894,888 B2
`
`21
`
`FG4A
`
`8
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 8 of 14
`Sheet 8 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`
`
`
`
`FIG.4B
`FIG.4B
`
`9
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 9 of 14
`Sheet 9 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`11
`11
`
`9
`9
`
`
`
`14
`14
`13
`13
`
`6
`5
`
`27
`
`25
`25
`
`27
`
`FIG.4C
`FIG.4C
`
`10
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 10 of 14
`Sheet 10 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`11
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 11 of 14
`Sheet 11 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`N.
`IN
`
`N
`N.
`
`N.
`I\
`
`FIG.5A
`
`F
`v
`N
`Ix
`
`CO
`00
`N
`rx
`
`LO
`L0
`N
`N
`
`6 I
`O
`
`NN
`‘
`
`O
`L0
`s N. N
`V-l\l\-
`
`N N
`
`CN N
`
`E
`t
`
`CY)
`(‘0
`N
`[x
`
`12
`
`12
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 12 of 14
`Sheet 12 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`N
`“-
`O)
`07
`
`sm V
`f"
`T—
`N.
`O)
`l\
`O)
`
`a
`»
`
`CN
`0]
`O)
`O)
`
`CY)
`or)
`O
`O)
`
`r.
`r
`v - CO
`r— 00
`N.
`[x
`
`O
`O
`LO
`L0.
`
`L
`LL
`
`827683
`
`FIG.SB
`
`13
`
`13
`
`

`

`U.S. Patent
`
`Feb. 22, 2011
`
`Sheet 13 of 14
`
`US 7,894,888 B2
`
`s
`LD
`
`O
`O
`
`N.
`r
`
`O)
`r
`
`OO
`r
`
`w
`CO
`r
`
`CN
`CO
`S
`
`v
`O
`r
`
`CN
`LO
`r
`
`CY)
`N
`
`CN
`S
`
`v-
`N
`st ||
`
`CN
`V
`| N |
`
`co
`CD
`
`--
`
`--
`
`r
`s
`
`v-
`ver
`v \O/ v
`
`-H
`
`Q9S
`N LO
`CN
`CO
`
`OO
`N s
`O
`v
`
`s V
`
`14
`
`

`

`U.S. Patent
`US. Patent
`
`Feb. 22, 2011
`Feb. 22, 2011
`
`Sheet 14 of 14
`Sheet 14 of 14
`
`US 7,894,888 B2
`US 7,894,888 B2
`
`
`
`FIG.7
`
`15
`
`15
`
`

`

`1.
`DEVICE AND METHOD FOR MEASURING
`THREE-LEAD ECG IN A WRISTWATCH
`
`BACKGROUND OF THE INVENTION
`
`10
`
`15
`
`25
`
`30
`
`35
`
`1. Field of Invention
`This invention relates to a wristwatch with the function of
`measuring and processing a three-lead electrocardiogram
`(ECG) and more particularly, to a wrist-watch that is capable
`of measuring a three-lead ECG and providing event-related
`reminders for alerting users to measure an ECG in a critical
`moment determined by a sensing system or by the user. In
`addition, this invention is related to a method for measuring
`the three-lead ECG by the wristwatch.
`2. Description of Related Art
`Regularly tracking on changes in cardiac function is usu
`ally suggested for the elderly to maintain fitness. In a hospital,
`a three-lead ECG measurement has been widely used to
`monitor cardiac function. While accepting a cardiac assess
`ment in the hospital, it can often cost time, can increase the
`risk to get an infection and may not be convenient for the
`elderly. To be capable of measuring an ECG conveniently,
`portable ECG recording devices have been developed.
`Although portable ECG measuring devices have been
`introduced to record an ECG outside a hospital, the need to
`wear electrodes on the chest and carry cables connecting to
`the device makes it difficult to use on an ambulatory and daily
`base. Some wristwatches have been made for measuring heart
`rates or heart pulses but have not been equipped with a three
`lead ECG measurement and arrhythmia analysis which pro
`vides more detail information about the cardiac system.
`A standard three-lead ECG indicates a measurement of
`cardiac potentials leaving from the heart in 3 directions,
`toward the right-arm (RA), toward the left-arm (LA), and
`toward the left leg (LL). The lead I of the ECG is the cardiac
`potential difference between LA and RA (LA-RA), the lead
`II of the ECG is the cardiac potential difference between LL
`and RA (LL-RA), and the lead III of the ECG is the cardiac
`potential difference between LL and LA (LL-LA). Also, 3
`augmented leads (lead AVR, AVL and AVF) can be calculated
`40
`based on the standard three-lead ECG. Lead AVR is RA
`(LA+LL)/2=-(I+II)/2, lead AVL is LA-(RA+LL)/2=(I-III)/
`2, and lead AVF is LL-(RA+LA)/2=(II+III)/2.
`To meet the need of convenience and medical expertise, it
`is desirable to have a portable device, e.g. a wristwatch, which
`can measure and process a three-lead ECG without extra
`cable connections. Further, the three-lead ECG data acquired
`by a portable device, which can be recorded and transmitted
`to a personal and hospital computer, will be highly convenient
`and needed.
`
`45
`
`50
`
`SUMMARY OF THE INVENTION
`
`The object of this invention is to provide a portable device,
`a wristwatch, with the function of measuring, recording, and
`analyzing a three-lead ECG. Three electrodes are placed on
`the front-side/lateral-side, the back-side, and the strap of the
`watch separately. When the watch is worn, the electrode in the
`back-side of the watch contacts the first hand which wears the
`watch. Then, a finger from the second hand contacting the
`electrode on the front-side of the watch can forman electrical
`loop to measure the lead I of ECG (ECG potential difference
`between right and left arms). To measure the other 2 ECG
`leads, the wearer needs to bring the electrode on the strap to
`touch his/her own abdominal area or left leg, while the fingers
`from the second hand still press on the electrode on the
`front-side of the watch to form a triangle electrical loop. The
`
`55
`
`60
`
`65
`
`US 7,894,888 B2
`
`2
`potential difference between each pair of electrodes repre
`sents a lead. The lead I of ECG is the potential difference
`between the left arm and right arm, the lead II of ECG is the
`potential difference between the left leg (or abdomen) and
`right arm and the lead III of ECG is the potential difference
`between the left arm and left leg (or abdomen). Therefore, a
`standard three-lead ECG can be obtained based on the 3
`electrodes. In addition, the trigger to start an ECG measure
`ment is an electrode panel that comprises sensing elements on
`the front-side/lateral-side of the watch. The sensing elements
`can be detectors of pressure, impedance or infrared to recog
`nize the contact or press of a finger. The watch has the func
`tion of providing reminders, which can be sound, light, vibra
`tion or all of them, to notify the user to measure an ECG. The
`events which can induce reminders comprise alarm setups,
`activity levels, temperature changes, etc. and temperature
`changes etc.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIGS. 1A and 1B show front and back views of one
`embodiment of the invention;
`FIG. 2 shows a back view of one embodiment to present a
`location of the electrode on the strap;
`FIGS. 3A, 3B, 3C, and 3D show an example of the use of
`the invention and demonstrate how to place the wristwatch to
`make electrodes be contacted by both hands and abdomen;
`FIGS. 4A, 4B, 4C, and 4D show another example of the use
`of the invention and demonstrate how to place the wristwatch
`to make electrodes be contacted by both hands and left leg:
`FIGS.5A, 5B, and 5C show examples of the structures of
`the sensing elements;
`FIG. 6 shows the schematic diagram of three-lead ECG
`loops with right and left hand modes; and
`FIG. 7 shows a general block diagram illustrating one
`embodiment of the invention and the flow for signal collect
`ing, processing and transferring.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`Referring to FIGS. 1A and 1B, there are shown views of a
`preferred embodiment of the invention including back-side 1
`and a front-side 2 of the wristwatch. In the back-side 1 of the
`watch, an electrode 3 is inserted for touching the hand which
`wears the watch. In the front-side 2 of the watch, there is
`another electrode 4 for fingers from the other hand to press on,
`while the watch is worn on one hand. An electrode panel 12,
`comprising the electrode 4 on the front-side 2 of the watch
`and sensing elements 6, is placed on the front-side 2 of the
`watch. The sensing elements 6 can detect pressure, imped
`ance or infrared for recognizing the contact or press made by
`fingers to initiate an ECG measurement. A display 7. Such as
`a liquid crystal display (LCD), is on the front-side 2 of the
`watch. The display 7 can demonstrate in text 15, which
`includes time, heart rate, condition (normal or arrhythmia),
`and graph/animation, for an event reminding 13 and ECG
`waveforms 14. To modify watch function and displaying
`contents, at least 1 control button 9 is set on the watch. To
`exhibit event-related reminders, output devices for light8 (for
`example, light emitting diode (LED), LCD, organic light
`emitting diode (OLED)) and/or sound 10 (for example, a
`miniature buZZer or speaker) may be positioned in the watch
`with an opening on the watch Surface. The watch can also
`have a miniature motor inside to provide the function of
`vibration as a reminder.
`
`16
`
`

`

`US 7,894,888 B2
`
`3
`Referring to FIG. 2, an electrode 5 is placed on the outer
`side of the strap 11 of the watch for making connection with
`the left leg or abdomen to form electrical loops for a three
`lead ECG measurement.
`Referring to FIGS. 3A to 3D, one of the methods according 5
`to the invention for measuring three-lead ECG is illustrated.
`The watch 25 is worn tightly on one hand 22 (FIG. 3A). In
`FIG. 3B, one finger 23 from the other hand 21 presses on the
`sensing elements 6, and another finger 24 from the other hand
`21 presses on the electrode 4 on the front 2 of the watch 10
`simultaneously. At the same time, the electrode 5 (as shown in
`FIG. 2) on the strap 11 of the watch 25 contacts the skin in the
`wearer's abdominal area to form a triangle electrical loop. In
`addition, the placement of fingers can be altered to be one
`finger (any one finger 27 from the other hand in FIG. 3C, or 15
`the thumb 28 from the other hand in FIG. 3D) touching both
`the sensing elements 6 and electrode 4 on the electrode panel
`12 to trigger and make a measurement. After measuring an
`ECG, the data obtained can be stored in a flash memory
`plugged or inserted in the watch and/or transmitted via a 20
`wireless module 56 to a personal computer or hospital com
`puter 62.
`Referring to FIGS. 4A to 4D, another method according to
`the invention for measuring a three-lead ECG is illustrated.
`The watch is worn tightly on one hand 22 (FIG. 4A). In FIG. 25
`4B, one finger 23 from the other hand 21 presses on the
`sensing elements 6, and another finger 24 from the other hand
`21 presses on the electrode 4 on the front 2 of the watch
`simultaneously. At the same time, the electrode 5 (as shown in
`FIG. 1) on the wrist-band 11 of the watch contacts the skin on 30
`the wearer's left thigh area 31 to form a triangle electrical
`loop. In addition, the placement offingers can be altered to be
`one finger (any one finger 27 from the other hand in FIG. 4C,
`or the thumb 28 from the other hand in FIG. 4D) touching
`both the sensing elements 6 and electrode 4 on the electrode 35
`panel 12 to trigger and make a measurement. After measuring
`an ECG, the data obtained can be stored in a flash memory
`plugged or inserted in the watch and/or transmitted via a
`wireless module 56 to a personal computer or hospital com
`puter 62.
`40
`Referring to FIGS. 5A to 5C, 3 examples of sensing ele
`ments are demonstrated. Firstly, FIG. 5A shows a switch
`sensor 77 on a circuitboard 76 embedded in the watch. When
`one finger 71 presses in a direction 73 on a soft surface 72 of
`the sensing elements 6, a solid pellet 78 inserted in a floating 45
`broad 74 under the soft surface 72 is pushed down to turn on
`the switch 77 to start an ECG measurement. The floating
`broad is supported by springs 75 which stand on the circuit
`board 76. Secondly, FIG. 5B shows a light source 82 and a
`photo detector 83 on the circuit board 76 embedded in the 50
`watch. When a finger 71 is placed on a small hole which is on
`the Surface 81 of the sensing elements 6, the light (e.g. infra
`red) released by the light source 82 reaches in the direction 84
`the finger and reflects in the direction 85 back to the photo
`detector 83. After receiving light, the photo detector 83 gen- 55
`erates a potential to initiate an ECG measurement. Thirdly,
`FIG. 5C shows an impedance detecting circuit is set on the
`circuit board 76 embedded in the watch. When one finger 71
`touches a conductive Surface 91 on the sensing elements 6, a
`low-energy current 93 released by a wire 92 goes through 60
`fingertip 71 and back to the circuit board via another wire 94.
`The voltage difference between the output and input currents
`to the circuit board 76 is used to be a trigger to start an ECG
`measurement.
`Referring to FIG. 6, the method to obtain three-lead ECG is 65
`shown. The method to compute a standard three-lead ECG is
`described as follows: the lead I of ECG is the cardiac potential
`
`4
`difference between LA and RA (LA-RA), the lead II of ECG
`is the cardiac potential difference between LL and RA (LL
`RA) and the lead III of ECG is the cardiac potential difference
`between LL and LA (LL-LA). In this invention, the potential
`difference between each pair of electrodes is obtained by
`differential amplifiers 41, 42, 43. The identification of ECG
`leads depends on which hand is wearing the watch. When the
`watch is worn on the left hand, the potential difference
`between electrodes 3, 4 on the front-side and back-side of 5 on
`the front-side and the band of the watch is identified as lead
`451, and the potential difference between electrodes 3, 5 on
`the back-side and band of the watch is identified as lead III
`461.
`When the watch is worn on the right hand, the potential
`difference between electrodes 3, 4 on the front-side and back
`side of the watch is identified as negative lead I 442, the
`potential difference between electrodes 4, 5 on the front-side
`and the band of the watch is identified as negative lead III 452,
`and the potential difference between electrodes 3, 5 on the
`back-side and band of the watch is identified as negative lead
`II 462. The reference potential of the ECG circuits is set as the
`combination of the signals from the 3 electrodes. All ECG
`data goes through filters 47, 48, 49 to sharpen signals and then
`an analog-to-digital converter 50 to change analog signals to
`be digital data for a microprocessor 54 disposed in the watch.
`For an augmented three-lead ECG, the calculation method is
`according to the standard three-lead ECG as follows: Lead
`AVR is RA-(LA+LL)/2=-(I+II)/2, lead AVL is LA-(RA+
`LL)/2=(I-III)/2, and lead AVF is LL (RA+LA)/2=(II+III)/
`2. All circuits for ECG measuring are embedded and hidden
`inside the watch or the strap 11.
`Referring to FIG. 7, a general block diagram of the embodi
`ment of the invention and the flow of signal collecting, pro
`cessing and transferring is illustrated. The invention has a
`microprocessor 54 in the center. The inputs for inducing
`spontaneous reminders for users to measure an ECG can be
`provided by a sensing element 51 such as for activity levels
`and temperature changes. Activity levels are measured by the
`sensing element 51 in the form of an accelerometer, and
`temperature changes are measured by the sensing element 51
`in the form of a thermometer. The signals collected by the
`sensing element 51 pass an A/D converter 50 before entering
`the microprocessor 54. When the activity level of users is
`intensive for a critical period of time or when the temperature
`changes dramatically, the microprocessor 54 will order the
`reminding function to be active in a form of light, Sound or
`vibration 58 or all of them. Also, users 59 of the invention can
`use the control button 60 or wireless settings to set a time
`alarm for reminding him/her-self to measure an ECG. After
`receiving the reminding signals, users 59 may start an ECG
`measurement by pressing on the electrode panel 53 and posi
`tioning the watch as in FIG. 2 and FIG.3 or turn offreminders
`by operating the control buttons 60. After measuring, ECG
`circuits 52 sent acquired data through the A/D converter 50 to
`the microprocessor 54 process and transfer data to the flash
`memory 55, wireless module 56, and/or display 57. The dis
`play 57 can show users 59 time, heart rate, waveforms and any
`other information 61, such as activity level and temperature,
`if needed. The data recorded in the flash memory 55 or trans
`mitted by the wireless module 56 can eventually reach per
`Sonal or hospital computers 62 for cardiac experts to make
`specific analyses.
`A unique design and concept of a wristwatch which can
`measure a three-lead ECG is shown and described here. Many
`changes and modifications can be carried out without depart
`ing the scope of the specific embodiment described herein.
`The description herein is intended to be illustrated only and is
`
`17
`
`

`

`5
`not intended to be limitative. The invention is intended to be
`limited only by the scope of the appended claims.
`What is claimed is:
`1. A wristwatch for measuring a three-lead ECG, compris
`1ng:
`a case including a front side and a back side opposite to the
`front side;
`a strap attached to both ends of the case and including an
`inside Surface and an outside Surface, with the inside
`surface being intermediate the back side and the outside
`Surface;
`a circuit board disposed in the case;
`a first electrode positioned on the outside surface of the
`strap;
`a second electrode positioned on the front side of the case;
`a third electrode positioned on the back side of the case,
`with the first, second and third electrodes being electri
`cally separate for detecting Voltage differences gener
`ated by cardiac systems, with the circuitboard detecting
`Voltage differences generated by the first and second
`electrodes, by the first and third electrodes, and by the
`second and third electrodes to obtain a set of ECG data
`comprising ECG lead I, ECG lead II, and ECG lead III;
`a display disposed on the case;
`a control panel comprising one of the electrodes and a
`plurality of sensing elements; and
`at least one control button for inputting information,
`changing function, and modifying user's mode of the
`wristwatch.
`2. The wristwatch of claim 1, wherein the electrode and the
`sensing elements of the control panel are adapted to be
`touched separately.
`3. The wristwatch of claim 1, wherein the control panel
`further includes an integrated unit covering both the electrode
`and the sensing elements of the control panel to allow the
`electrode and the sensing elements of the control panel to be
`activated simultaneously by one touch; wherein the inte
`grated unit is an interface activating both the electrode and the
`sensing elements of the control panel by one touch.
`4. The wristwatch of claim 1, further comprising an alert
`ing device disposed in the case alerting a user to practice the
`ECG measurement.
`5. The wristwatch of claim 4, wherein the alerting device
`emits light, makes sound, or vibrates.
`6. The wristwatch of claim 4, wherein the alerting device is
`an LED or OLED emitting light.
`7. The wristwatch of claim 4, wherein the alerting device is
`an OLED or LCD flashing light.
`8. The wristwatch of claim 4, wherein the alerting device is
`a buZZeror speaker.
`9. The wristwatch of claim 4, wherein the alerting device is
`a miniature vibrating motor for vibrating.
`
`10
`
`15
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`US 7,894,888 B2
`
`6
`10. The wristwatch of claim 4, further comprising a sensing
`element measuring temperature changes as a reference value
`to activate the alerting device.
`11. The wristwatch of claim 4, further comprising a sensing
`element measuring a user's activity levels as a reference value
`to activate the alerting device.
`12. The wristwatch of claim 1, further comprising a trans
`mission device for data transmission after the set of ECG data
`is obtained; with the transmission device comprising at least
`one of a flash memory and a wireless networkfortransmitting
`data to a remote personal or hospital computer.
`13. The wristwatch of claim 1, further comprising a wire
`less module receiving wireless control signals from a remote
`computer for modifying settings of the wristwatch.
`14. The wristwatch of claim 1, wherein the plurality of
`sensing elements are activated by infrared, pressure, or
`impedance.
`15. The wristwatch of claim 1, wherein the circuit board
`processes said set of ECG databased on a wearing hand mode
`which includes a left-hand mode and a right-hand mode.
`16. The wristwatch of claim 15, wherein when the circuit
`board processes said set of ECG data in said left-hand mode,
`the ECG lead I is taken as a potential difference between
`the second and third electrodes disposed on the back side
`and the front side of the case;
`the ECG lead II is taken as a potential difference between
`the first and second electrodes disposed on the strap and
`the front side of the case; and
`the ECG lead III is taken as a potential difference between
`the first and third electrodes disposed on the back side of
`the case and the strap.
`17. The wristwatch of claim 15, wherein when the circuit
`board processes said set of ECG data in said right-hand mode,
`the ECG lead I is taken as a negative potential difference
`between the second and third electrodes disposed on the
`back side and the front side of the case;
`the ECG lead II is taken as a potential difference between
`the first and third electrodes disposed on the strap and the
`back side of the case; and
`the ECG lead III is taken as a potential difference between
`the first and second electrodes disposed on the front side
`of the case and the strap.
`18. The wristwatch of claim 1, wherein the first, second and
`third electrodes are used to separately contact the skin in a
`right upper limb, a left upper limb, and a trunk of the user to
`obtain said set of ECG data.
`19. The wristwatch of claim 1, wherein the first, second and
`third electrodes are used to separately contact the skin in a
`right upper limb, a left upper limb, and a left lower limb of the
`user to obtain said set of ECG data.
`
`18
`
`