U.S. patent application number 09/840255 was filed with the patent office on 2001-08-16 for wireless myoelectric control apparatus and methods.
Invention is credited to Hill, William Colyer, Pereira, Fernando Carlos, Singer, Yoram, Terveen, Loren Gilbert.
Application Number | 20010014441 09/840255 |
Document ID | / |
Family ID | 26801658 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010014441 |
Kind Code |
A1 |
Hill, William Colyer ; et
al. |
August 16, 2001 |
Wireless myoelectric control apparatus and methods
Abstract
Myoelectric and wireless technologies are used for the control
of a portable electronic device, such as a cellular telephone or a
personal digital assistant (PDA). That is, a portable electronic
device has a wireless myoelectric user interface. An apparatus
includes a material which forms a forearm or wrist band,
myoelectric sensors attached to the band, a digital processor
coupled to the myoelectric sensors, and a wireless transmitter
coupled to the digital processor. The apparatus is operative to
sense and detect particular hand and/or finger gestures, and to
broadcast control signals corresponding to the gestures for
operative control of the portable electronic device.
Inventors: |
Hill, William Colyer;
(Montville, NJ) ; Pereira, Fernando Carlos;
(Westfield, NJ) ; Singer, Yoram; (Murray Hill,
NJ) ; Terveen, Loren Gilbert; (Basking Ridge,
NJ) |
Correspondence
Address: |
Samuel H. Dworetsky
AT&T CORP.
P.O. Box 4110
Middletown
NJ
07748-4110
US
|
Family ID: |
26801658 |
Appl. No.: |
09/840255 |
Filed: |
April 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09840255 |
Apr 23, 2001 |
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09419376 |
Oct 15, 1999 |
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6244873 |
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60104534 |
Oct 16, 1998 |
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Current U.S.
Class: |
434/236 |
Current CPC
Class: |
G06F 3/015 20130101;
G06F 3/017 20130101 |
Class at
Publication: |
434/236 |
International
Class: |
G09B 019/00 |
Claims
What is claimed is:
1. A wireless myoelectric control apparatus suitable for use in
operating a portable electronic device, comprising: a material
which forms a forearm or wrist band; one or more myoelectric
sensors carried on said band; a digital processor; said digital
processor coupled to said myoelectric sensors; a wireless
transmitter; and said wireless transmitter coupled to said digital
processor.
2. The apparatus according to claim 1, wherein said digital
processor further comprises a gesture detector.
3. The apparatus according to claim 1, further comprising: said
digital processor comprising a gesture detector; and memory coupled
to said digital processor.
4. The apparatus according to claim 1, further comprising: said
digital processor comprising a gesture detector; memory coupled to
said digital processor; and said memory for storing a plurality of
gesture patterns.
5. The apparatus according to claim 1, wherein said digital
processor further comprises a training module.
6. The apparatus according to claim 1, wherein said material is
elastic.
7. The apparatus according to claim 1, further comprising: an
antenna; and said antenna coupled to said wireless transmitter.
8. An apparatus, comprising: one or more myoelectric sensors; a
gesture detector; said gesture detector coupled to said myoelectric
sensors; an output of said gesture detector providing a portable
electronic device command corresponding to a detected gesture; a
wireless transmitter coupled to the output of said gesture
detector; and an antenna coupled to said wireless transmitter.
9. The apparatus according to claim 8, further comprising: a
training module; and said training module coupled to said
myoelectric sensors.
10. The apparatus according to claim 8, further comprising: memory;
said memory coupled to said gesture detector; and said memory for
stored a plurality of gesture patterns.
11. A battery-operable portable electronic device, comprising: a
wireless myoelectric user interface.
12. The device according to claim 11, wherein said wireless
myoelectric user interface comprises: a wireless receiver.
13. The device according to claim 11, wherein said wireless
myoelectric user interface comprises: electronic circuitry,
including: a wireless receiver; said wireless receiver operative to
receive user interface commands; a processor; and said processor
operative to receive and process the received user interface
commands.
14. The device according to claim 12, further comprising: a
housing; and said electronic circuitry carried in said housing.
15. The device according to claim 11, wherein the device comprises
one of a portable computer, a portable wireless or cellular
telephone, a portable audio player, a portable calculator, and a
personal digital assistant (PDA).
16. A method of processing myoelectric sensor signals, comprising:
receiving myoelectric sensor signals indicative of one of a
plurality of hand or finger gestures; detecting one of the
plurality of gestures based on the myoelectric sensor signals; and
selectively issuing one of a plurality of commands associated with
the detected gesture.
17. The method according to claim 16, further comprising:
broadcasting the command with a wireless transmitter.
18. The method according to claim 17, further comprising:
amplifying the myoelectric sensor signals; and digitizing the
amplified myoelectric sensor signals.
19. The method according to claim 16, further comprising: in
response to detecting, activating a wireless transmitter to
broadcast the command.
20. The method according to claim 16, wherein the plurality of hand
or finger gestures includes a first gesture which reflects contact
between a thumb and an index finger of a human hand, a second
gesture which reflects contact between the thumb and a middle
finger of the human hand, and a third gesture which reflects
contact between the thumb and a ring finger of the human hand.
Description
[0001] This application claims benefit of the priority of U.S.
Provisional Application Ser. No. 60/104534, filed Oct. 16,
1998.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the field of user
interfaces for portable electronic devices, as well as to the field
of wireless myoelectric control.
[0004] 2. Description of the Related Art
[0005] Portable electronic devices have become increasingly
popular. These devices can operate with the use of a small battery
pack or battery cells. Examples of these devices include wireless
or cellular telephones, personal digital assistants (PDAs), and
audio or music delivery devices. Some devices have become
increasingly small such that they are now deemed "pocketable"
and/or "wearable."
[0006] A portable electronic device typically has a user interface
for operative control. Most if not all conventional user interfaces
for such portable electronic devices employ physical buttons,
stylus, or voice control. In some devices, a large number of
operations or functions are possible with the user interface.
[0007] One major shortcoming of a button or stylus-based user
interface is that the user must physically retrieve and position
the portable electronic device appropriately for physical contact
therewith. In addition, as the size of a device becomes smaller,
the interface becomes increasingly inappropriate from an ergonomic
standpoint. The major shortcoming of a voice-controlled interface
is that the user must speak openly in such a way that other nearby
people may hear.
[0008] Myoelectric technologies are known and have been used for
control in some applications. In U.S. Pat. No. 4,149,716, a head
band with electrodes is used to generate signals for wired control
of visual displays in a television display game. In U.S. Pat. No.
5,482,051, electromyographic sensors are placed on the back of a
user's hand to provide for the realistic "squeezing of objects" in
a virtual reality application. U.S. Pat. No. 2,252,102 discloses
orthotic and prosthetic devices which are controlled with
myoswitches in connection with wireless communication. As described
in U.S. Pat. No. 5,679,004, a body suit has myoelectric sensors for
contact with an arm, where the signals therefrom are broadcasted to
a remote station for comparison of teacher and student motions.
U.S. Pat. No. 5,692,417 describes the combined use of EEG and EMG
signals to produce control signals for electronic musical
instruments and video games. None of these patents describes a
wireless myoelectric apparatus for operative control of a portable
electronic device with a relatively large number of clearly
discernible human commands.
[0009] Accordingly, there is an existing need to provide a
convenient and easy-to-use user interface for small portable
electronic devices.
SUMMARY OF THE INVENTION
[0010] As described herein, the inventive methods and apparatus
involve the use of myoelectric and wireless technology for the
control of a portable electronic device. That is, the inventive
portable electronic device has a wireless myoelectric user
interface.
[0011] In one aspect of the invention, the apparatus comprises a
material which forms a band, myoelectric sensors attached to the
band, a digital processor coupled to the myoelectric sensors, and a
wireless transmitter coupled to the digital processor. The band is
sized and configured to fit around a human forearm or wrist. In
general, the apparatus is operative to sense and detect particular
hand and/or finger gestures, and to broadcast control signals
corresponding to the gestures for operative control of the portable
electronic device.
[0012] The apparatus may employ a method of receiving and
digitizing signals from the myoelectric sensors, determining
whether a correlation exists between the digitized signal data and
one of a plurality of prestored gesture patterns, selecting and
generating a control signal or message associated with the
prestored gesture pattern when a correlation exists, and modulating
and transmitting a radio frequency (RF) signal with the control
signal for control of the portable electronic device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a diagram of a wireless communication system
having a wireless myoelectric apparatus and a portable electronic
device.
[0014] FIG. 2 is a schematic block diagram of electronic circuitry
of the wireless myoelectric apparatus of FIG. 1.
[0015] FIG. 3 is a flowchart describing a method of processing
myoelectric sensor signals which may be carried out by the wireless
myoelectric apparatus of FIG. 1.
[0016] FIG. 4 is a method of processing control signals which may
be carried out by the portable electronic device of FIG. 1.
[0017] FIG. 5 is a flowchart describing a method of learning
gestures which may be carried out by the wireless myoelectric
apparatus of FIG. 1.
[0018] FIG. 6 is a table showing exemplary detectable gestures of
the wireless myoelectric apparatus of FIG. 1, exemplary controlled
functions of the portable electronic device of FIG. 1, and
exemplary relationships between such gestures and functions.
[0019] FIG. 7 is another table showing exemplary detectable
gestures of the wireless myoelectric apparatus of FIG. 1, exemplary
controlled functions of the portable electronic device of FIG. 1,
and exemplary relationships between such gestures and
functions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIG. 1 is a diagram of a wireless communication system 100
including a wireless myoelectric apparatus 102 and a portable
electronic device 104. Apparatus 102 is operative to communicate to
portable electronic device 104 via radio frequency (RF) signals 106
or other suitable over-the-air signals.
[0021] Apparatus 102 includes a material which forms a band 108,
myoelectric sensors 110, electronic circuitry 112, and an antenna
114. Band 108 has a hole 116, and is sized and configured to fit
around a human forearm in a "snug-fit" fashion. Band 108 may be
referred to as a "sleeve." In the preferred embodiment, the
material of band 108 is elastic, and may be made of well-known
spandex or spandex-like material. Thus, band 108 may be stretched
for attachment to and detachment from the forearm. In an alternate
embodiment, the material of band 108 is a sheet of cloth having
snaps or Velcro.TM. for attachment and detachment. In another
embodiment, two bands with myoelectric sensors are used; one for
the left forearm and a similar one for the right forearm.
[0022] The band may be alternatively sized and configured to cover
a part of the forearm that is smaller than that shown as being
covered by band 108. As an example, FIG. 1 shows a band 150, which
may be referred to as a "wristband". Band 150 has a dimension along
the length of the forearm that is smaller than that shown by band
108. This dimension may be about three inches (7.62 cm), for
example, but may vary; for example, the dimension may vary from
around one inch (5.08 cm) to five inches (12.7 cm). Preferably,
band 150 is not suited to cover most of the forearm, but rather to
cover only an upper part of the forearm (e.g., where the muscle is
the thickest). Left and right wristbands may be used in combination
as well.
[0023] Myoelectric sensors 110, such as a myoelectric sensor 118,
are coupled to electronic circuitry 112 via conductors 120, such as
a conductor 122. Myoelectric sensors 110 may be adhesively attached
to band 108, and conductors 120 may be embedded within and/or
carried on band 108. In any case, each of myoelectric sensors 110
is attached to and carried on band 108 such that, when the forearm
carries the band 108, the myoelectric sensor makes contact with the
outer surface of the forearm.
[0024] Electronic circuitry 112, which is described below in
relation to FIG. 2, may be carried on band 108 as indicated in FIG.
1. In one embodiment, electronic circuitry 112 is carried in a
pocket (not shown) of band 108. The pocket may be formed to
completely enclose electronic circuitry 112, or remain partially
open. In an alternate embodiment, electronic circuitry 112 is not
carried on band 108 but rather contained outside of band 108,
carried in a small housing (not shown), and coupled to myoelectric
sensors 110 and/or conductors 120 via wires (not shown). Electronic
circuitry 112 is coupled to antenna 106 which is configured to send
commands via RF signals 106 to portable electronic device 104.
[0025] FIG. 2 is a schematic block diagram of electrical circuitry
112 of wireless myoelectric apparatus 102 of FIG. 1. Electronic
circuitry 112 includes myoelectric sensors 110, a signal amplifier
202, a gesture detector 204, a training module 206, memory 208, an
encryption module 216, a transmitter 218, and antenna 114, coupled
as indicated in FIG. 2. Memory 208 may include a read-only memory
(ROM) 210, a random access memory (RAM) 212, and an
electrically-erasable/programmable ROM (EEPROM) 214. Preferably,
gesture detector 204, training module 206, and at least portions of
memory 208 are included in a digital processor 220. Myoelectric
sensors 110 of FIG. 2 refers to the sensors from the one or more
bands in use. To provide energy for electronic circuitry 112, a
portable energy source 222 is included. Portable energy source 222
may include a battery pack or one or more battery cells.
[0026] Referring back to FIG. 1, portable electronic device 104
generally includes electronic circuitry 138 carried in a housing
(see outline of 104). Electronic circuitry 138 shown in FIG. 1
allows for communication and control of portable electronic device
104 by apparatus 102. Electronic circuitry 138 includes a processor
124, a receiver 126, an antenna 128, a user interface 132 (which
may include an earpiece or headset 134), and a decryption module
136, coupled as indicated.
[0027] Examples of portable electronic device 104 include a
portable audio player (having an AM/FM radio, tape cassette, and/or
compact disc (CD) player), a wireless or cellular telephone, a
personal digital assistant (PDA), a computer, a calculator, to name
a few. As apparent, the electronic circuitry of portable electronic
device 104 may include circuitry and devices in addition to
electrical circuitry 138 shown in FIG. 1, and will depend on the
particular chosen application.
[0028] Portable electronic device 104 may be freely carried by a
user since it can operate without externally fixed wired
connections. To make this possible and convenient, electronic
circuitry 138 is powered by a portable energy source 130 which is
carried by the housing. Portable energy source 130 may include a
battery pack or one or more battery cells. Portable electronic
device 104 also has a small size and a light weight. In one
embodiment, portable electronic device 104 is sized to fit within a
hand of a user; it may be referred to as a "hand-held" device.
Portable electronic device 104 may be small enough to be considered
"wearable" or "pocketable". For example, portable electronic device
104 may have dimensions no greater than 3".times.4".times.1/2", and
a weight no greater than eight ounces. Thus, a user may carry or
wear portable electronic device 104 outside of his/her view and
accessibility, while listening to audio from portable electronic
device 104 via earpiece 134.
[0029] Generally, apparatus 102 is a wireless myoelectric interface
for portable electronic device 104. Put another way, portable
electronic device 104 has a wireless myoelectric user interface. In
one embodiment, the conventional user interface 132 of portable
electronic device 104 does not exist (except for perhaps earpiece
104) and the wireless myoelectric interface is the primary user
interface for portable electronic device 104. That is, buttons or
stylus that would otherwise be present are missing from portable
electronic device 104. In another embodiment, conventional user
interface 132 is present but may overridden by apparatus 102.
[0030] FIG. 3 is a flowchart describing a method of processing
myoelectric sensor signals. This method may be carried out by
wireless myoelectric apparatus 102. As apparent, at least some
steps of the methods described herein are embodied and implemented
in connection with software and a digital processor. In the
following description, FIGS. 2 and 3 will be referred to in
combination with FIG. 1.
[0031] A user has band 108 attached to his/her forearm or wrist. As
the user moves hands and fingers, myoelectric sensors 110 pick up
electrical signals from muscles that control the hands and fingers.
Beginning at a start block 300 of FIG. 3, signals from myoelectric
sensors 110 are received (step 302), amplified by signal amplifier
202 (step 304), and digitized by digital processor 220 (step 306).
Gesture detector 204 detects whether a correlation exists between
the digitized data and one of several prestored data patterns in
memory 208 (step 308). Each one of the prestored data patterns
corresponds to a particular gesture that is uniquely detectable by
gesture detector 204. Preferably, these patterns are stored in
EEPROM 214, and may be transferred to RAM 212 during operation.
[0032] If no correlation exists at step 308, the flowchart ends at
an end block 316. If a correlation exists at step 308, gesture
detector 204 selects and generates a control signal or message that
corresponds to the prestored data pattern (step 310). The control
signal or message may be referred to or regarded as a "command" for
portable electronic device 104. Next, gesture detector 204 enables
encryption module 216 to encrypt the control signal or message
(step 312). Gesture detector 204 also enables transmitter 218 so
that an RF signal is modulated by the control signal or message and
transmitted from antenna 114 (step 314) (see RF signals 106).
Assuming portable electronic device 104 is within close proximity
to apparatus 102, portable electronic device 104 will receive RF
signals 106. Other electronic devices within close proximity will
receive RF signals 106 as well. The flowchart ends at the end block
316, but the method may be repeated for continuous operation.
[0033] FIG. 4 is a flowchart describing a method of processing
control signals or commands. This method may be carried out by
portable electronic device 104 of FIG. 1. This method may follow or
occur at substantially the same time as the method of FIG. 3.
[0034] Beginning at a start block 400 of FIG. 4, antenna 128 and
receiver 126 receive and demodulate RF signals 106 broadcasted by
apparatus 102 (step 402). Decryption module 136 attempts to decrypt
the received signals (step 404). If the signals cannot be decrypted
at step 404, then the flowchart ends at an end block 410. If the
signals are decrypted at step 404, processor 124 obtains the
control signal or message corresponding to the particular gesture
(step 406). Advantageously, the signals can only be decrypted by
portable electronic device 104 and not other nearby devices.
Processor 124 uniquely associates the control signal or message
with a particular function. Once the association is made, processor
124 performs that function (step 408). The flowchart ends at an end
block 410, but may be repeated for continuous operation.
[0035] Preferably, the user receives confirmation for whether a
particular gesture has been detected and/or acted upon by portable
electronic device 104. The confirmation may be provided at and by
apparatus 102 (given an appropriate user interface), or at and by
portable electronic device 104 (e.g., appropriate audio provided at
earpiece 134). This confirmation may take place after step 308 of
FIG. 3, or around steps 406 and 408 of FIG. 4.
[0036] FIG. 6 is a table showing exemplary detectable gestures of
wireless myoelectric apparatus 102 of FIG. 1, exemplary controlled
functions of the portable electronic device 104 of FIG. 2, and
exemplary relationships between such gestures and functions. The
table in FIG. 6 shows four finger gestures detectable by gesture
detector 204, where each gesture is uniquely associated with a
function of portable electronic device 104. In the table, symbols
are used to denote the finger gestures. Here, "T" signifies the
thumb, "i" signifies the index finger, "r" signifies the ring
finger, and "p" signifies the pinky finger. A dash "-" is used
between these signifiers to indicate physical contact therebetween.
For example, a gesture "T-r" indicates the thumb in contact with
the ring finger of the same hand.
[0037] As indicated in FIG. 6, the thumb in contact with the index
finger corresponds to a "forward" command or function; the thumb in
contact with the middle finger corresponds to a "play" command or
function; the thumb in contact with the ring finger corresponds to
a "stop" command or function; and the thumb in contact with the
pinky finger corresponds to a "rewind" command or function. As
apparent, these or similar functional associations may be used in,
for example, audio/video player applications, voice mail retrieval
applications, etc.
[0038] As alternatively indicated in FIG. 6, the thumb in contact
with the index finger corresponds to a "scroll up" command or
function; the thumb in contact with the middle finger corresponds
to a "s elect" command or function; and the thumb in contact with
the ring finger corresponds to a "scroll down" command or function.
As apparent, these or similar functional associations may be used
in, for example, scrolling through long data lists, selecting
prestored telephone numbers for dialing, voice mail applications,
etc.
[0039] FIG. 7 is another table showing other exemplary detectable
gestures of apparatus 102 of FIG. 1, exemplary controlled functions
of portable electronic device 104 of FIG. 1, and exemplary
relationships between such gestures and functions. The table in
FIG. 7 shows thirteen finger gestures detectable by gesture
detector 204, where each gesture is uniquely associated with a
function of portable electronic device 104. In FIG. 7, the same
symbols are used as in the table of FIG. 6. Here, however, the
control is provided by gestures from both hands, the left hand
("LH") and the right hand ("RH").
[0040] As indicated in FIG. 7, combinations of simultaneous
gestures from both the left and right hands may be associated with
a particular function. For example, the number "1" is selected in
response to the left thumb being in contact with the left index
finger while the right thumb is in contact with the right index
finger; the number "2" is selected in response to the left thumb
being in contact with the left index finger while the right thumb
is in contact with the right middle finger. Similarly, the number
"4" is selected in response to the left thumb being in contact with
the left middle finger while the right thumb is in contact with the
right index finger; the number "5" is selected in response to the
left thumb being in contact with the left middle finger while the
right thumb is in contact with the right middle finger, etc. As
apparent, these or similar functional associations may be used in,
for example, selecting from one of many retrievable items, manually
selecting telephone numbers for dialing, etc.
[0041] Also as indicated in FIG. 7, a right hand "snap" between the
right thumb and the right middle finger provides a "SEND" command
or an "END" command, depending on what state portable electronic
device 104 is in. For example, if portable electronic device 104
provides cellular telephone functionality, the right hand snap
provides a "SEND" command or function when portable electronic
device 104 is in an idle or standby mode, and an "END" command or
function when portable electronic device 104 is in a talk or
communication mode. As another example, if portable electronic
device 104 provides telephone functionality, the right hand snap
provides an "OFF-HOOK" command or function when portable electronic
device 104 is on-hook and an "ON-HOOK" command or function when
portable electronic device 104 is off-hook. As another example, the
right hand snap provides a "POWER-UP" command or function when
portable electronic device 104 is powered down, and a "POWER-DOWN"
command or function when portable electronic device 104 is powered
up.
[0042] Preferably, apparatus 102 employs what are referred to as
"gesture-activated transmission" and "gesture-activated interface
enabling." "Gesture-activated transmission" allows for the enabling
and disabling of the RF broadcast based on whether any gestures are
detected. That is, when a gesture is detected, the transmitter is
enabled and RF signals are broadcasted; when no gesture is
detected, the transmitter is disabled and no RF signals are
broadcasted. More precisely, when a gesture is detected, the
transmitter is enabled for a first predetermined time period before
the command is sent. After the command is sent, the transmitter
remains enabled for a second predetermined time period. If no other
gesture is detected during the second predetermined time period,
the transmitter is disabled and the RF signal broadcast ceases. If
another gesture is detected during the second predetermined time
period, however, the next command is immediately sent and the
second predetermined time period is reset so that the RF broadcast
is maintained for that time. In addition to prolonging battery
life, this feature allows for sufficient signal hysteresis and
receiver "pre-time" in order to adequately receive signals and
commands.
[0043] On the other hand, "gesture-activated interface enabling"
allows for the enabling and disabling of gesture commands based on
a predetermined gesture. As an example, a right hand snap may
activate the gesture interface and a left hand snap may deactivate
the gesture interface. Given a right hand snap, commands and
functions are issued and performed "as normal" for some set of
predetermined gestures (e.g., those in FIG. 6). That is, the right
hand snap "enables" the commands. However, no commands or functions
are issued or performed for any predetermined gestures following a
left hand snap, until the right hand snap is again given. This
feature allows for the convenient activation and deactivation of
the interface when necessary. Any suitable gestures may be applied,
and the same gesture may provide for both activation and
deactivation using concepts similar to that described in relation
to the "SEND" and "END" functions in FIG. 7.
[0044] Referring now to FIG. 5, a flowchart describing a method of
learning gestures is shown. This method may be carried out by
wireless myoelectric apparatus 102 of FIG. 1, which may be referred
to as a wireless adaptive myoelectric interface ("WAMI") in this
context. Beginning at a start block 500, a "gesture learning mode"
is enabled for apparatus 102. This mode may be activated at initial
powerup (prior to any operation), in response to a particular
gesture or activation, or in response to a detection of some error
between incoming gestures and prestored patterns. Once the gesture
learning mode is enabled at step 502, an indication is provided as
to what gesture is to be learned (step 504). This indication may be
provided at and by apparatus 104, but preferably it is provided at
and by portable electronic device 104 (e.g., an audio indication at
earpiece 134).
[0045] In response, the user performs the indicated gesture and
signals are generated at myoelectric sensors 110. Digital processor
220 and training module 206 receive and process the signals (step
506), and store the results in memory 208. As indicated at step
508, the same gesture and processing may be repeated for a
predetermined number of repetitions or until training module 206 is
"satisfied" with the data already received. After any repetition of
the gesture, training module 206 determines a gesture pattern
associated with the gesture (step 510) and stores it in memory 208
(step 512). Preferably, the gesture pattern is stored in EEPROM
214.
[0046] If there are no more gestures to learn at step 514, the
flowchart ends at an end block 516. If there are more gestures to
learn at step 514, the next gesture is selected (step 518) and the
method repeats at step 504. The number of gestures to learn for
portable electronic device 104 may be relatively large, and in some
implementations on the order of 10-20 gestures. The number and the
positioning of myoelectric sensors 110 and the discernability of
digital processor 220 are collectively configured so that detection
is possible with a relative large number of hand gestures, such as
those indicated in FIGS. 6 and 7. As one example, one to three
myoelectric sensors 110 are positioned on band 108 so that twenty
or more finger or hand gestures can be recognized.
[0047] Thus, training module 206 as described in relation to FIG. 5
allows for accurate learning for a given individual. Preferably,
the determining of the gesture patterns is performed using a
discriminative algorithm. The learning algorithm first maps the
high dimensional myoelectric recordings into an internal compact
representation. Next, a machine learning technique called
"boosting" is used to find a set of discriminative features.
Finally, the features are combined into a single highly accurate,
yet compact, gesture classifier. For best performance, special
attention is given to potential crosstalk from synchronous muscle
activations as described in "Surface Myoelectric Crosstalk Among
Muscles Of The Leg," C. DeLuca, R. Merletti, EEG & Clin.
Neurophysiol., vol. 69, pp. 568-575, 1988, and "Detection Of Motor
Unit Action Potentials With Surface Electrodes: Influence Of
Electrode Size And Spacing," A. Fuglevand et al., Biol. Cybern.,
vol. 67, pp. 143-153, 1992.
[0048] As described, the inventive wireless myoelectric control
apparatus is suitable for use in operating a portable electronic
device. The wireless myoelectric control apparatus may include a
material which forms a forearm or wrist band, one or more
myoelectric sensors carried on the band; a digital processor
coupled to the myoelectric sensors; and a wireless transmitter
coupled to the digital processor.
[0049] In other inventive aspects, a battery-operable portable
electronic device has a wireless myoelectric user interface. This
device may have a housing and electronic circuitry carried in the
housing. The electronic circuitry includes at least part of the
wireless myoelectric user interface (e.g., the wireless
receiver).
[0050] In yet other aspects, an apparatus includes one or more
myoelectric sensors; a gesture detector coupled to said myoelectric
sensors; an output of said gesture detector providing a portable
electronic device command corresponding to a detected gesture; a
wireless transmitter coupled to the output of said gesture
detector; and an antenna coupled to said wireless transmitter.
[0051] The apparatus may employ a method of receiving and
digitizing signals from the myoelectric sensors, determining
whether a correlation exists between the digitized signal data and
one of a plurality of prestored gesture patterns, selecting and
generating a control signal or message associated with the
prestored gesture pattern when a correlation exists, and modulating
and transmitting a radio frequency (RF) signal with the control
signal for control of the portable electronic device.
[0052] Also, an inventive method of processing myoelectric sensor
signals comprises the steps of receiving myoelectric sensor signals
indicative of one of a plurality of hand or finger gestures, where
the plurality of gestures includes a first gesture which reflects
contact between a thumb and an index finger of a human hand, a
second gesture which reflects contact between the thumb and a
middle finger of the human hand, and a third gesture which reflects
contact between the thumb and a ring finger of the human hand;
detecting one of the plurality of gestures based on the myoelectric
sensor signals; and selectively issuing one of a plurality of
commands based on the detected gesture.
[0053] The methods described have been used in connection with
apparatus 102 and portable electronic device 104. However, the
methods may be employed between apparatus 102 and a number of
wireless-controlled devices that are owned and operated by the user
(including portable electronic device 104).
[0054] As readily apparent, the inventive aspects described herein
provide several advantages in the field of myoelectric control. The
present invention is a more particular breakthrough in connection
with user interfaces for portable electronic devices. Thus, the
scope of the invention should be understood to be quite broad and
warrant a broad range of equivalent structures and
functionalities.
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