Note: Descriptions are shown in the official language in which they were submitted.
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WIRELESS CONTROL FOR DENTAL E(,~UIPMENT
Cross-reference to related applications
The present application claims the benefit of United States provisional
patent application number 60/524,911 filed on November 26, 2003, the
disclosure of which is herewith incorporated by reference in its entirety.
Field of the Invention
The present invention relates to dental instruments and more
particularly to control devices for dental instruments.
Background of the Invention
Many tools ara operated by electrical power in a dentist's office. Unless they
are battery powered, such tools are tethered and corulected to the electrical
source by cables. Since most power inlets are installed around the walls of a
dentist's office, such cables traverse the room where dental procedures are
performed. Some tools are operated by manual foot pedals, which are also
corulected by cables to the power source. The cables can be a potential hazard
to both the dental professional and patient.
In addition, the complexity and clutter tends to reduce the efficiency of
dental procedures by slowing the activities of the dental professional.
Complexity and clutter in the environment alsa increases the risk of error and
accident. Tllus, there remains a need for another means of control that can
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r educe complexity and clutter in the working envir onment of the dental
professional and minimize potential hazards.
Summar~of the Invention
The present invention relates to a wireless remote control for dental
equipment, such as dental sealer tools, dental drills, prophy angles, rotary
instr uments.
In an exemplary embodiment of the present invention, a wireless
control such as a foot pedal is used to control the operation of an ultrasonic
dental tool comprising a base unit, a handpiece comprising a handle and an
insert, and a wireless control switch such as a foot switch. The handpiece is
coupled at one end (i.e., the proximal end) to an electrical energy source, a
fluid source and/or gas, via a cable. The cable includes a hose to provide a
fluid (e.g., water), and/or a gas, and conductors to provide electrical
energy.
The other end (i.e., the distal end) of the handpiece has an opening intended
to receive an insert with a transducer (e.g., a magnetostrictive transducer)
carried on the insert. The transducer extends from the proximal end of the
insert into a hollow interior of the handpiece. An ultrasonically vibrated tip
extends from a distal end of the insert. The handle has means therein which is
adapted to impart a vibration to the insert. Such means are well known in the
art and may be mechanical, magnetostrictive or piezoelectric in nature. The
dental tool described can be in the form of a dental sealer.
When the wireless control is a foot switch, depressing the foot switch
will result in activation of the ultrasonic handpiece and also delivery of
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cooling water to the insert tip. When the foot is removed from the foot
control, both the ultrasonic handpiece and water are shut off.
The wireless control, such as the foot switch, replaces manual and foot
operated controls formerly connected by cables to the dental tool and/or to
the power supply. This removes a potential safety hazard in the dentist's
office and makes the equipment control more versatile and easier to adapt to
various office conditions.
In another exemplary embodiment of the invention, the dental tool
comprises a base unit, a handpiece comprising a handle, a dental insert and a
wireless control switch such as a foot switch. The dental tool is corulected
to a
power, and/or fluid, and/or an air supply source through a conduit cable, so
that the supply source, though coupled to the tool, is located at a position
remote from the working end of the tool. The wireless foot switch, in the form
of such as a pedal, is located within easy reach of the operator to permit
t~.irn-
on and/or ttun-off of the tool. The signaling means which simply and yet
effectively provides for selective automatic turn on and turn off of the tool
while totally eliminating the need for an electrical connection between the
main supply unit and the remote control unit again removes a potential safety
hazard in the dentist's office and makes the equipment control more versatile
and easier to adapt to various office conditions. In addition to controlling
the
on and off of the dental tool, the wireless module can also be programmed to
control the speed of the tool by a switch on the tool.
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The dental tool includes a dental drill, a rotary instrument, an
endodontic file and a prophy angle. A common or different handpiece can be
used with various inserts to form these tools. For example, a dental drill
comprises a drill bit; a rotary tool comprises an insert, such as a mufti-use
diamond dental bur; a dental carbide bur; a dental sintered diamond bur; a
dental diamond disc; a dental laboratory tungsten carbide cutter; a steel
dental bur; an endodontic file; and a proplly angle comprising a longitudinal
body and a prophy cup. The insert comprises a shank or attachment adapted
to be fitted into the handpiece.
In addition to having wireless control in a dental office, a still further
embodiment of the invention comprises a wireless control such as a foot
switch for use with, especially rotary dental instruments or drills, in a
dental
laboratory. A dental drill or a rotary dental tool such as ~a carbide bur, is
connected to a power supply through a conduit cable so that the power
supply source, though again coupled to the handpiece, is located at a position
remote from the working end of the handpiece. The wireless control in the
form of such as a foot pedal is located within easy reach of the operator to
permit hirn-on and/or turn-off of the instrument, thus again eliminating the
need for an electrical connection between the main power supply unit and the
remote control unit. This removes a potential safety hazard in a dental
laboratory and makes the equipment control more versatile and easier to
adapt to various laboratory conditions.
In still a further aspect of the present invention, the above exemplary
dental tools can also be fitted with at least one light source. The light
source
can draw its power supply from the same or different power source that
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supplies the power for tile operations of the tool, or the light source can
draw
its power from the energy created by the ultrasonic vibrations. A wireless
control means for the selective energizing of the light supply source can be
separate or the same as the wireless means that controls the on and off of the
dental tool. if a separate control is used, it can also be located within easy
reach of the operator to permit tzun-on and/or turn-off of the light supply
source through simple foot pedal control provided within a remote control
unit
These and other advantages and features of flue invention will be more
readily understood in relation to the following detailed description of the
invention, which is provided in conjunction with the accompanying
drawings.
Brief Description of the Drawings
Figure 1 shows an ultrasonic dental instrument according to one
embodiment of the invention including a handpiece and a wireless foot pedal;
Figur a 2 shows a r otaiy dental instrument accor ding to one
embodiment of the invention including a llandpiece and a wireless foot pedal;
Figure 3 shows a perspective view of a dental instrument, including a
supply apparatus and a foot-pedal device, according to one embodiment of
the invention;
Figures 4a and 4b show dental burs for use in a wirelessly controlled
dental instrument according to one embodiment of the invention; and
Figure 5 shows an abrasive disk for use in a wirelessly controlled
dental instrument according to one embodiment of the invention;
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Figure 6 shows a dental file according to one embodiment of the
invention;
Figure 7 shows a dental prophy angle attachment according to one
embodiment of the invention;
Figure 8 shows aspects of a wireless control transmitter in block
diagram form according to one embodiment of the invention;
Figure 9 shows aspects of a wireless control receiver in block diagram
form according to one embodiment of the invention;
Figure 10 shows a transmitter for an energy-efficient wireless conhol
system according to one embodiment of the invention;
Figure 11 shows a receiver for an energy-efficient wireless control
system according to one embodiment of the invention;
Figure 12 shows a transmitter for an analog wireless control system
according to one embodiment of the invention;
Figure 13 shaves a transmitter for an analog wireless control system
according to another embodiment of the invention;
Figure 14 shows a transmitter for a digital wireless control system
according to a further embodiment of the invention;
Figure 15 shows a foot pedal device including a rotary digital encoder
according to one embodiment of the invention;
Figur a 16 shows a foot pedal device including a linear digital encoder
according to one embodiment of the invention;
Figure 17 shows a transmitter for a wireless control system including a
microprocessor device according to one embodiment of the invention;
Figure 18 shows a receiver for a digital wireless control system
according to one embodiment of the invention;
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Figure 19 shows a receiver for a wireless control system according to
one embodiment of the invention;
Figure 20 shows a receiver for a wireless control system according to a
further embodiment of the invention;
Figure 21 shows a further receiver for a wireless control system
according to another embodiment of tile invention;
Figure 22 shows another receiver for a wireless control system
according to still another embodiment of the invention;
Figure 23 shows another receiver, including a microprocessor, for a
dental instrument wireless control system.
Detailed Description of the Invention
Conventional ultr asonic units have a foots-witch connected to tile unit
with a cable. When the fact control is depressed, a solenoid valve is
activated
permitting tile flow of water and electricity through the regulator and
through the solenoid, to the handpiece and over the dental insert or tip.
Vibr ation of the inser t is thus initiated by energizing the ultr asonic
genes ation
mechanism.
Figur a 1 illustrates an embodiment of the present invention in
the form of an ultrasonic dental system 100 including an ultrasonic dental
tool 102 attached to an electrical energy & fluid source 104, via a cable 106
along with a wireless control switch, shown here as a wireless foot pedal 110,
conveniently disposed within easy reach by the dental professional. The cable
106 includes a conduit for carrying fluid as well as wires for carrying
electrical
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power and signals from the electrical energy and fluid source 104 to the
ultrasonic dental tool 102. The ultrasonic dental tool 102 W eludes a
llandpiece
112 and an insex't 114 inserted into the handpiece 112. The activation of the
electrical ever gy and fluid sour ce control is carried out by means of the
wireless foot pedal 110 located within communication range of the wireless
control. The wireless foot pedal 110 is also located within easy reach by the
dental professional.
In a preferred embodiment, the handpiece 112 is coupled at one end
(i.e., a pr oximal end 116) to an electrical ever gy and fluid source 104 via
a
cable 106. Tlle other end (i.e., a distal end 118) of the handpiece leas an
opening intended to r eceive therein an insert 114 with a transducer 122 which
is adapted to impart a vibration to a tip of the insert 124. The transducer
122
may be, for example, mechanical, magnetostrictive or piezoelectric in nature.
The transducer 122 extends from an aperhire at the distal end 118 of the
handpiece 112 into a hollow interior of the handpiece. An ultrasonically
vibrated tip 124 extends from a distal end of the insert. In one exemplary
embodiment, the insert 114 is a dental sealer.
In use, a dental practitioner touches a tip of the sealer lightly against a
tooth. The transducer 122 imparts a vibratory motion to the tip of the sealer.
The ener gy of this vibratory motion, is mechanically coupled to the tooth and
plaque and calculus are consequently removed from the tooth.
According to one embodiment of the invention, depressing the foot
pedal 110 results in activation of the ultrasonic transducer 122, and also in
the
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delivery of cooling water to the insert tip. In one embodiment, when the foot
pedal 110 is released, both the ultrasonic handpiece and water are shut off.
The absence of wires coupled between the foot pedal 110 and the
electrical energy and fluid source 104 obviates a potential safety hazard in
the
dentist's office or dental laboratory and makes the equipment control more
versatile and easier to adapt to various office conditions. This type of
control
can be adapted to control the speed of a device, such as a dentist's drill, or
a
rotary instrument, as shown and described in more detail below.
The ultrasonic insert can be made of metal, plastic or metallic alloys.
Suitable metals or metallic alloys include stainless steel, titanium, titanium
alloys such as nickel-titanium and titanium-aluminum-vanadium alloys;
aluminum and aluminum alloys; and combinations thereof. The preferred
materials are stainless steel and titanium alloys. Suitable plastics include
high
temperature plastics such as ULTEM~, which is an amorphous thermoplastic
polyetherimide or Xenoy~ resin, which is a composite of polycarbonate and
polybutyleneterephthalate or Lexan~ plastic, which is a copolymer of
polycarbonate and isophthalate terephthalate resorcinol resin, all available
from GE Plastics, or any other suitable resin plastic or composite. In
general,
the metal tips can be used for general cleaning, scaling and the like, while
the
non-metal tips may be used around sensitive gum lines, on expensive
restorations such as cro«ns, bridges, and/or around titanium implants which
may be more easily damaged by a metal tip.
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In addition to being an ultrasonic sealer, the dental instrument can also
be of a non-ultrasonic type, such as a vibratory type, which utilizes a
different
' handpiece from the ultrasonic handpiece described above in FIG. 1. The
handpiece can be a handpiece used in dental drills and rotary instruments as
5 shown, for example, in Fig. 2 below. Thus, the insert can also be in the
form
of an endodontic dental file, a drill, prophy angles or other instruments
useful
in the dental examination room or dental laboratory.
Although conventional dental drills, dental files, proplly angles and
10 rotary instruments are not normally fitted with a foot switch, such
instruments are also amenable to having a wireless switch for turning the
instrument on and off, or to vary the speed of operation, as noted above.
Thus, in another exemplary embodiment of the invention, a dental tool 130 as
shown in FIG. 2, includes a llandpiece 132 which is different from an
ultrasonic handpiece as shown in FIG. 1. The dental tool also includes a
wireless foot switch 110. The dental instrument is also corulected to an air,
water and power supply sour ce 13,6 through a conduit cable 138, so that the
supply sour ce 136, though coupled to the handpiece, is located at a position
remote from the working end of the handpiece 132.
The wireless foot switch 110 is again located within easy reach of the
operator to permit turn-on and/or turn-off of the instrument. The signaling
means can either provide for selective automatic hirn on and turn off of the
drill, or to vary the speed of the drill. This totally eliminates the need for
an
electrical cormection between the main supply unit and the remote control
unit and again removes a potential safety hazard in the dentist's office and
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11
makes the equipment control more versatile and easier to adapt to various
office conditions.
FIG. 3 shows a perspective view' of a dental instrument 1200 according
to one embodiment of the invention. According to the illustrated
embodiment, the dental instrument 1200 includes a hand-piece 1202 and an
insert 1204. The insert holds an ultrasonic sealer tip 1206 and includes a
light
sour ce 1208 such as a light emitting diode. The handpiece 1202 is coupled to
a
supply apparatus 1210 with an umbilical cable 1212. In the illustrated case,
the supply apparatus 1210 includes an ultrasonic power supply and a wireless
receiver. Also shown is a foot-pedal device 1214. The~foot-pedal device 1214
includes a first pedal portion 1216 adapted to control activation of the
ultr asonic power supply within the supply apparatus 1210, and to thereby
control activation of the ultrasonic sealer tip 1206. The foot-pedal device
1214
also includes a second pedal portion 1218 adapted to control a state of the
light source 1208. According to various embodiments of the invention,
applying pressure to the first foot-pedal portion 1216 allows simple on/off
control of the ultr asonic tool 1206 or continuously varying control of the
ultrasonic tool 1206. Also, according to various embodiments of the
invention, applying pressure to the second foot-pedal portion 1218 allows
simple on/off control of the light source 1208 or continuously varying control
of the light source 1208.
Rotary dental instruments such as multi-use diamond dental burs;
dental carbide burs; dental sintered diamond burs; dental diamond discs;
dental laboratory tungsten carbide cutters; dental steel burs; and surgical
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12
drills are all contemplated in the present invention. These rotary dental
inserts and other cutting tools for surgical placements of dental and
orthopedic implants, developed to aid dental professionals in removing
damaged portions of the tooth, including root canals, reconstructing and
shaping the restored tooth or replacement tootle, including dental implants,
all can be equipped with a wireless control.
Figures 4a and 4b show exemplary rotary dental burs 1250. The figure
19a bur 1250 comprises a shank 1252 having a non-abrading shank portion
I
1254 adapted to be fitted into a dental handpiece (not shown), and an
abrading working portion 1256 connecting to and extending outwardly from
tile non-abrading shank portion 1254. The abrading working portion 1256
comprises an abrading surface.
Tlle shank 1252 can be made of any suitable metal, such as that used in
the ultrasonic insert. Tlle preferred materials are stainless steel and
titanium
alloys. These metals have good flexibility and resistance to torsional
breakage.
The abrading surfaces can be formed in a number of different ways.
One way of generating an abrading surface is by coating or embedding
diamond particles or clops 1258 into the working surface of working portion
1256 of the substrate shank 1252. The abrading particles can in turn be coated
with a coating such as a titanium nitride or a diamond-like carbon coating.
Another way of generating an abrading sur face is by forming cutting
surfaces or edges on the surface of the working portion 1256 of the shank 1252
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13
as shown in figure 4b, connecting to and extending downwardly from the
shank portion. The abrading portion can also comprise a coating, such as
titanium nitride coating or diamond-like carbon coating.
Figure 5 shows an abrading tool for use i11 yet another embodiment of
the invention. An abrading disc 1270 comprises a flexible substrate 1272
adapted for mounting onto a driver (not shown) and having diamond
particles 1274 coated or embedded or having cutting edges 1276 formed
thereon the surface of the substrate, the abrading surface can also be coated
with a coating such as titanium nitride or flexible diamond-like coating that
substantially covers the abrading surface during use. The disc can be
attached to shank portion.
The flexible substrate 1272 can be made of metal or polymer. The
surface of the substr ate is coated or embedded with diamond particles 1274
having cutting edges formed thereon the surface of the substrate. The
abrading surface can in turn be coated with a diamond-like carbon coating.
The materials suitable for use as a flexible substrate of the disc include
those identified above as suitable also for the shanks of dental burs. One of
skill in the art will appreciate that the desirable characteristics of
substrate
materials include good flexibility.
One of skill in the art will appreciate that a wide variety of other
shapes and configurations of cutting tools may be employed in a dental tool
having wireless remote control, such as the already mentioned dental drill, in
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14
the form of a drill bit insert (not shown) an endodontic file and reamer, as
shown in FIG. 6 a prophy angle, as shown, for example, in figure 7, and such
as those described i1z U.S. Patent Nos. 4,097,995, 4,266,933, 4,854,870,
5,007,832,
5,028,233, 5,062,796, 5,156,547, 5,209,658, 5,328,369, 5,642,994, 5,667,383,
5,692,901, 5,697,773, 6,099,309 and 6,203,322, incorporated herein by
reference.
In one pr eferr ed embodiment of the present invention, the above
exemplary dental tools can also be fitted with at least one light source 101,
as
shown in FIG. 3 above. The light source can draw its power from the same or
different power source that supplies the power for the operations of the tool,
or the light source 1208 can draw its power from the already available
ultrasonic vibrational energy already created by the ultrasonic vibrations.
The wireless control discussed above is also applicable here. As noted,
the footswitch can be designed to indicate only on/off conditions where
proportional control is not necessary, since some ultrasonic dental hygiene
tools only need an on/off control. For such applications, the footswitch need
only have two states, also to be described in more detail below.
As noted above, figure 6 shows a dental file adapted for use in a dental
instrument according to the present invention. The dental file 179 includes a
shaft 180 with a smooth portion 181 adapted to be colleted to a rotary
instrument and an abrasive pOltloll 182 adapted to the shaping of tootle,
bone,
or other dental substrate. According to one preferred embodiment, the
material of the dental file 179 is stainless steel. According to another
preferred embodiment, the material of the dental file is an alloy of nickel
and
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titanium. Further description of dental files suitable for employment within
the invention is found in United States patents numbered 5,527,205, 5,464,362,
5,941,760, 5,623,674, 5,655,950 and 5,762,541, incorporated herein by
reference.
5 As also noted above, figure ~ shows a prophy angle attachment 190
accor ding to one aspect of the invention. As illustrated, the prophy angle
attachment includes a handle 191 with a proximal end 192 and a distal end
193. A mechanical coupling 194 at the distal end is adapted to receive
mechanical po'~er into the prophy angle. In the illustrated embodiment, a
10 polishing cup 195 is coupled to a rotary mechanical output of the proplly
angle at the distal end 193 thereof. As will be understood by one of skill of
the art, wide variety of polishing and cutting tools may be employed in place
of tile polishing cup 195.
15 Figure 8 shows, in block diagram form, a wireless transmitter 200
according to one aspect of the invention. The wireless transmitter includes an
actuator 202, a tr ansducer 204, a radio frequency modulator 206, a radio
frequency tr ansmitter 208, and an antenna 210. The actuator 202 is
mechanically coupled to the transducer 204. The achiator 202 is adapted to
receive a mechanical input, for example the pressure of a foot against a foot
petal, and to provide a responsive mechanical output to tile tr artsducer 204.
The transducer 204 receives the mechanical output of the actuator at a
mechanical input of the transducer and produces a signal output, such as an
electrical signal output at an output of the transducer. The signal output of
the transducer 204 is received at an input of the radio frequency modulator
206. The radio frequency modulator 206 produces a radio frequency output
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16
that is received at an input of the radio frequency transmitter 208. Tlle
radio
frequency transmitter 208 is electrically coupled to the antenna 210 and
drives
the antenna in accordance with the radio frequency signal that it receives
from the radio frequency modulator 206.
According to one embodiment of invention, the actuator 202 is a foot
pedal such as that identified with reference numeral 110 in figure 1. The
transducer 204 senses a position and/or a motion of the foot pedal. According
to one embodiment, the transducer 204 is an optical encoder device. Also
according to one embodiment of invention, the achlator, transducer and RF
encoding device produce a signal that is proportional to a mechanical signal
applied to the actuator 202.
Figure 9 shows, in block diagram form, a wireless receiver 250 for
controlling a dental instrument. The wireless receiver includes an antenna
252, a receiver 254 and RF decoder 256, and a control device 258. The antenna
252 is coupled to the receiver 250 which is, in turn, coupled to tile RF
decoder
25G. The RF decoder is coupled to the tool control 258. According to one
embodiment of the invention, a signal received at the antenna 252
corresponds to a signal transmitted from the antenna 210 of transmitter 200
(as shown in figure 8). An output signal of the taol control 258 is thereby
related to the mechanical signal applied to the actuator 202.
As shown in figures 8 and 9, the actuating device connects to a
transducer to convert the physical motion of the actuator into an electrical
signal proportional to the motion of the actuator. The electrical signal
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17
representing the motion of the achiator is coded into a radio frequency signal
that is transmitted by a low power RF transmitter through a small antenna
210. Alternatively, the actual position of the actuator can be converted to a
digital signal, encoded into an RF signal, transmitted to the receiver 250,
and
decoded. It does not matter whether the signal carries position indicator or
movement indicator signals. Either can be made to operate the dental tool
when transmitted to a receiver 250.
Figure 10 shows, in block diagram form, a transmitter 300 for an
' energy-efficient wireless control system according to one embodiment of the
invention. As will be understood by one of skill in the art, electrical
batteries
have a finite operational lifetime. Although some batteries are rechargeable,
the time inter val between char ge cycles is nevertheless finite. To the
extent
that replacable or rechargeable batteries is required for a wireless
transmitter
according to the invention, the advantages of the invention are
correspondingly limited. Ther efor a it is valuable to have a transmitter that
conserves battery life. The transmitter 300 is adapted to transmit dental tool
control signals without unduly taxing its battery.
Transmitter 300 includes a first single pole double throw (SPDT) switch
302 and a second SPDT switch 304. A common connection to 306 of switch
302 is coupled to a first capacitor terminal 308 of a capacitor 310. A second
capacitor terminal 312 of capacitor 310 is coupled through a resistor 314 to a
first output terminal 316 of switch 302. The output terminal 312 is also
coupled to an ilzput terminal 318 of a first code transmitter 320.
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The footswitch sends a first signal when the actuator is pressed and a
second signal when the actuator is released. The first signal, when received
at
the base unit, turns on the equipment. The reception of the second signal
causes the equipment to turn off. In the footswitch, it is preferred that
there is
no electrical activity after the initial signal is sent so as to conserve
energy in
the battery that powers the device. The footswitch is preferably battery
powered in most embodiments so that the cables presently needed for the
footswitch operation can also be completely abandoned.
In this embodiment, powering only the signaling of an on and off
signal allows the footswitch to operate far hundreds of activations before the
battery must be replenished (if rechargeable) or replaced (if not).
One approach for such on/off control means is to provide an electrical
circuit including switch means mounted within the remote contr of unit and
coupled across a pair of conductive leads extending between the remote
control unit and the supply source. The switch may be selectively turned on
and off in order to respectively energize and deenergize the dental tool or
instrument.
A battery 322 has a first battery terminal 324 coupled to ground and a
second battery terminal 326 coupled to a second output terminal 328 of switch
302. Second battery terminal 326 is also coupled to a third output terminal
330 of switch 304. A second capacitor 332 includes a third capacitor terminal
334 coupled to a second common terminal 336 of switch 304. A fotu th
capacitor terminal 338 of capacitor 332 is coupled through a second resistor
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19
340 to a fourth output terminal 342 of switch 304. The capacitor terminal 338
is also coupled to an input terminal 344 of a second code tr ansmitter 346.
The
first and second code transmitters 320, 346 are mutually connected to ground
at respective ground terminals 348, 350. Code transmitter 320 includes a first
pulldown resistor 352 coupled between input terminal 318 and ground
terminal 348. Code transmitter 346 includes a second pulldown transistor 354
coupled between input terminal 344 and ground terminal 350.
A pedal 356, or other actuator, is mechanically coupled to both
switches 302 and 304. When the pedal 356 is depressed by a user, both
switches 302 and 304 change their respective states substantially
simultaneously.
In a prelminary state, prior to depression of the pedal capacitor 310
discharged and terminal 334 of capacitor 332 is charged to the voltage of
battery 322 (e.g., 12 volts). Common terminal 306 is electrically connected to
output terminal 316, and common terminal 336 is electrically connected to
output terminal 330.
When the pedal is depressed the states of the switches transition (state
transition 1), so that common terminal 306 is electrically connected to output
terminal 328 and common terminal 336 electrically connected to output
terminal 342. In response to these electrical connections, terminal 308 of
capacitor 310 rapidly charges to battery voltage and terminal 334 of capacitor
332 substantially discharges through resistor 340 and pulldown resistor 354 to
ground potential. This discharging of terminal 334 occurs during a first
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transient time beginning immediately after state transition 1 and results in
an
electrical current that flows through resistors 340 and 354. A resulting first
transient voltage appears that terminal 344. This first transient voltage is
detected by internal circuitry of code transmitter 346, which responsively
transmits a wireless signal indicating depression of the pedal.
It should be noted that the first transient time is of limited duration, as
substantially determined by an RC time constant of capacitor 332 and
r esistors 340 and 354. Curr ent flows from the battery 322 to terminal 308 of
10 capacitor 310 during a similarly brief transient. Thereafter, no power is
required from the battery until the next state transition, with the exception
of
power required to compensate for any leakage current of capacitor 310. Such
leakage current will be substantially negligible.
15 When the pedal 356 is released, the states of the switches again
transition (state transition 2). The terminal 334 of capacitor 332 is
recharged
by a transient cu went OLlt of the battery 322. At the same time, terminal 308
of
capacitor 310 discharges by way of switch terminals 306 and 316, resistor 314
and resistor 352 to ground. A consequent transient electrical current flows
20 through resistors 349 and 352 that results in a transient voltage at
terminal
318. This transient voltage is detected by internal circuitry of transmitter
320.
The transmitter 320 responsively transmits a wireless signal indicating
release
of the pedal. Again, power transmission froze the battery 322 to capacitor 332
is limited by the brief duration of the second transient time interval.
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The internal circuitry of transmitter 320 and 346 may be configured to
transmit ~n~ireless signals of time and duration appropriate to the
environment
in which the wireless transmission systerri is to be employed. One of skill in
the art will understand, however, that by limiting the duration of signal
transmission, the power requirements of the transmitters 320, 346 may be
correspondingly limited.
Figure 11 shows a receiving circuit 400 of a wireless control system in
block diagram form. In the illustr ated embodiment, the receiving circuit 400
includes a first code receiver 402, a second code receiver 404 and a latch
circuit 406. The latch circuit 406 includes a first single pole single throw
electromechanical relay 403, a second single pole single throw
electromechanical r elay 410, and a double pole double throw
electromechanical relay 412.
The double pole double throw electromechanical relay 412 includes a
first switch 414. The first switch 414 has a first common terminal coupled to
a
second output terminal 416 of the latch circuit 406 and a third normally open
terminal coupled to a fourth output terminal 413 of the, latch circuit 406.
Relay 412 includes a second switcll 420 with a fifth common terminal
422 and a sixth normally open terminal 424. Also included in relay 412 is an
activation coil 426. The activation coil 426 is coupled at seventh output
terminal 428 to a source of ground potential.
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Relay 408 includes a third switch 430 with an eighth common terminal
432 coupled to a ninth input terminal 434 of activation coil 426. Relay 408
also
includes a tenth normally open terminal 436 mutually coupled to input
terminal 424 and to an eleventh output terminal 438 of first code receiver
402.
Relay 408 also includes a second activavon coil 440 with a pair of input
terminals 442, 444 coupled to respective output terminals of the first code
receiver 402.
Relay 410 includes a four th switch 446 with a 12th common terminal
448 coupled to common terminal 432 of relay 408. Relay 410 also includes a
13tH normally closed terminal 450 coupled to common terminal 422 of switch
420 (relay 412). Relay 410 also includes an activation coil 452 with a further
pair of input terminals 454, 456 coupled to respective output terminals of the
second code receiver 404.
First code receiver 402 is coupled to a power supply at power supply
terminals 458, 460. Second code receiver 404 is coupled to a power supply at
power supply terminals 462, 464. In addition, first code receiver 402 is
coupled to a source of ground potential at a signal ground terminal 466.
Flyback diodes 468, 470 and 472 are coupled across activation coils 440, 452
and 426 respectively.
In operation, code receiver 402 is adapted to receive a first signal from
a corresponding first code transmitter, such as code transmitter 346 as shown
in figure 10. Code receiver 404 is adapted to receive a second signal from a
corresponding second code transmitter, such as code transmitter 420 as
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shown in figure 10. Responsive to the receipt of the first signal by code
receiver and 402, latch cir cuit 406 is adapted to activate coil 426 and latch
normally open switch 414 in a closed position, such that a substantially short
circuit condition is provided between output terminals 416 and 418.
This substantially short-circuit condition may be used to control a
dental instrument. For example, a power supply rnay be coupled in series
with the switch 414 and the motor of an electric dental drill. Alternately,
'the
power supplies may be coupled in series with the switch 414 and an
ultrasonic power supply of an ultrasonic sealer instrument. In another
example, a power supply may be coupled in series with an activation coil of a
solenoid valve. The solenoid valve controls a flow of high-pressure air to a
pneumatic dental instrument, such as a pneumatic dental drill.
The latch cir cuit 406 operates as follows. When code receiver 402
receives the first signal, it impresses an electrical voltage sufficient to
activate
coil 440 across terminals 442, 444. The resulting electromagnet of coil 440
closes switch 430 and produces a substantially short-circuit between terminals
432 and 436. Terminal 438 is thus switchingly coupled to terminal 434. The
terminal 438 exhibits a voltage, taken with respect to ground terminal 466
(and thus with respect to terminal 428) that is sufficient to activate coil
426.
The consequent electromagnet of coil 426 closes both switch 414 and switch
420.
As discussed above, the closure of switch 420 is adapted to activate a
dental instrument. The closure of switch 420 provides a substantially short-
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circuit between terminals 422 and 424. This short-circuit, in series with
normally closed switch 446 provides a current path that is electrically
parallel
to switch 430. The parallel current path couples output terminal 438 to input
terminal 434 of coil 426. Consequently, coil 426 remains active after code
receiver 402 stops providing the activation voltage across terminals 442 and
444, and after switch 430 responsively reopens.
Since the active state of coil 426 keeps both switch is 420 and 414 in
their respective closed states, the dental instrument coupled to terminal 416
and 418 remains active. This active state persists until the circuit supplying
coil 426 is broken by the activation of relay 410. The latch circuit 406 is
said to
be in a latched state.
When a second signal (such as that generated by code transmitter 320
of figure 10) is received by second code receiver 404, receiver 404 activates
coil
452. Normally closed switch 446 is opened by active coil 452, and the
electrical path supplying current to coil 426 is rendered discontinuous. As
coil 426 is thus deactivated, switches 420 and 414 transition back to their
open
states, and the latch circuit 406 is said to be unlatched.
One of skill in the art swill appreciate that the above described
operation of receiving circuit 400 allows continuous operation of a dental
tool,
and subsequent termination of the tool's operation, to be effected with two
signals, each signal being of a relatively brief duration. As described above,
in relation to figure 10, it is beneficial to employ signals of 1'rief
duration in
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the context of a wireless dental instrument, since this allows conservation of
battery life in, for example, a battery powered foot pedal transmitter.
As illustrated in figures 10 and 11, the footswitch is designed to
indicate only on/off conditions where proportional control is not necessary,
as
some dental hygiene tools, for example, an ultrasonic dental tool, only need
an on/off control. For such applications, the footswitch need only have two
states.
10 In Figure 10, the footswitch is designed to send a first signal when the
actuator is pressed and a second signal when the actuator is released. The
first signal, when received at the receiver 400, hirns on the equipment. The
reception of the second signal causes the equipment to turn off. In the
footswitch, it is preferred that there is no electrical activity after the
initial
15 signal is sent so as to conserve the power in the battery that powers tile
device. The footswitch is preferably battery powered in most embodiments
so that the cables presently needed for the footswitch operation can also be
completely abandoned.
20 In this embodiment, powering only the signaling of an on and
off signal allows the footswitch to operate for hundreds of activations before
the battery must be replenished (if rechar geable) or replaced (if not).
It should be noted that the embodiments described above in relation to
25 figures 10 and 11 are merely exemplary. For example the latch circuit 406
of
figure 11 could really be implemented witr,, for example, transistor gates
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rather than electromechanical relays. Moreover, the plural code transmitters
of figure 10 and code receivers of figure 11 could readily be implemented as a
single transmitter and a single receiver respectively. In addition, in Iight
of
the foregoing disclosure, one of skill in the art would understand that there
are other means of producing a signal of limited duration, such as by digital
timer or by analog delay Iine.
Figure 12 shows, in block diagram form, a wireless transmitter 500
according to one embodiment of the invention. In the illustrated
embodiment, a single r adio tr ansmitter cir cuit 501 is employed to send more
than one signal. The wireless transmitter includes a foot pedal 502
operatively coupled to a mechanical input of a single pole double throw
switch 504. The switch 504 leas a first common input terminal 506 coupled to
a second terminal 508 of a power source sucll as, for example, an
electrochemical battery. A third terminal 512 of the power source is coupled
to a common node or source of ground potential.
A fourth terminal 514 of switch 504 is coupled through a first voltage
divider to the source of ground potential. The first voltage divider includes
fir st 516 and second 518 r esistor s mutually coupled in series; at common
fifth
terminal 520.
A sixth terminal 522 of switch 504 is coupled through a second voltage
divider to the source of ground potential. The second voltage divider
includes tllird 524 and fourth 52G resistors mutually coupled in series at a
common seventh terminal 528.
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Terminals 520 and 528 are mutually coupled to an input terminal 530
of a voltage controlled oscillator 532. As is understood by those of ordinary
skill of the art, a voltage controlled oscillator produces an output signal
having a frequency related to a voltage applied at an input of the oscillator
532.
The ratio of resistances, of resistors 516 and 518, of the first voltage
divider are selected to be different from the ratio of resistances, of
resistors
524 and 526, of the second voltage divider. Consequently, the electrical
potential of input terminal 530 depends on a state of the switch 504. Because
the output frequency of the oscillator 532 depends on the potential of input
terminal 530, changing the state of switch 504 changes a frequency of a signal
output at output terminal 534.
The output terminal 534 is coupled to an input terminal 536 of a
modulator 538. A further input terminal 540 of modulator 538 receives a
radio frequency signal from an output 542 of a radio frequency oscillator 544.
The modulator 538 produces a modulated signal at an output 546.
The modulated signal is received at an input 548 of a radio frequency
amplifier 550 which produces an amplified radio frequency signal at its
output 552. The output 552 of the radio frequency amplifier 550 is mutually
coupled to an antenna 554 and, through a ballast or load 556, to a source of
ground potential.
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In operation, the wireless transmitter 500 is placed on the floor of
examining room at a location convenient to the foot of the dentist. When the
dentist wishes the dental tool to operate, he or she depresses the foot pedal
502. This causes switch terminal 506 to be electrically corulected to terminal
522. Accordingly, the voltage of battery 510 is applied across resistors 524
and 526.
As is understood by one of skill of the art, a resulting first signal
voltage is impressed at node 528 that is different from the voltage of battery
510, and depends upon the voltage of battery 510 and upon the resistance
values of resistors 524 and 526. This first signal voltage is received at
input
530 of voltage controlled oscillator 532. It is characteristic of a voltage
controlled oscillator that an output frequency at output 534 corresponds to
the
voltage input at terminal 530. Thus a first output frequency is received at
modulator 538. The modulator 538 mixes this first output frequency with a
radio frequency carrier signal received from RF oscillator 544. The resulting
mixed (or RF modulated) signal it amplified with RF amplifier 550 and the
resulting amplified signal is used to drive antenna 554. This results in the
broadcasting of a first modulated RF signal over an area determined
principally by the signal power available from the RF amplifier 550 and the
configur ation of the antenna 554.
When the foot pedal 502 is released, the connection between terminals
506 and 522 is broken. Immediately thereafter, a new connection is formed
between terminal 506 and terminal 514. This acts to couple resistors 516 and
518 in series with battery 510. The voltage of battery 510 is dropped across
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tile series combination of resistor s 516 and 518, producing a second signal
voltage at node 520. This second signal voltage produces a second frequency
at the output 534 of the voltage controlled oscillator 532. As with the first
signal frequency, this second signal frequency is RF and modulated in the
modulator 538, amplified in the RF amplifier 550, and broadcast as a second
RF signal from the antenna 554.
The first and second RF signals are received at a receiving apparatus
that~includes a control system adapted to, for example, turn on a dental
instrument in response to receiving tile first RF signal and turn off the
dental
instrument in r esponse to receiving the second RF signal.
It will be understood by one of skill in the art that, in a fu rther
embodiment, the switch 504 may be replaced with a pulse generator circuit
adapted to respond to an input from foot pedal 502 by connecting terminal
506 and 514 for a particular time interval. The pulse generator circuit may be
configured to connect. terminal 506 to terminal 522 for a second particular
time interval upon release of the foot pedal 502. In this way, savings in
battery lifetime, along the lines of those described above in relation to
figures
10 and 11, may be achieved.
Figure 13 shows a wireless transmitter 600 according to another
embodiment of the invention, in block diagram form. As shown in figure 13,
a foot pedal 502 is mechanically coupled to a mechanical input of a variable
resistor 602. The variable resistor 602 has a first terminal 604 coupled to a
second terminal 606 of an electrical battery 608. A third terminal 612 of the
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electrical battery 608 is coupled to a common node 610, which is, in one
embodiment, at ground potential. A fourth terminal 614 of the variable
resistor 602 is also coupled to the common node 610.
The mechanical input of resistor 602 is adapted to vary respective
resistances between output terminal 616, and terminals 604 and 614.
Consequently, the voltage divider arrangement shown produces a voltage at
terminal 616 that varies in relation to the degree to which foot pedal 502 is
depressed.
The variable voltage at terminal 616 is received at an input 618 of a
voltage controlled oscillator 620. The voltage controlled oscillator also has
a
first power supply terminal coupled to battery terminal 606 and second
power supply terminal coupled to common node 610. An output 622 of the
voltage controlled oscillator is coupled to an input 624 of a buffer amplifier
626.
An output 628 of the buffer amplifier 626 is coupled to a first input 630
of a modulator cir cuit 632. A second input 634 of the modulator cir coif is
connected to an output 636 of a radio frequency oscillator 638. The modulator
circuit 632 has an output 640 coupled to an input 642 of a radio frequency
(RF)
amplifier 644. An output 646 of the RF amplifier is mutually coupled to an
antenna 648 and, through a ballast, to a sour ce of ground potential.
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Like the voltage controlled oscillator G18, the buffer amplifier 626, the
modulator circuit 632 and the RF amplifier each has a power terminal coupled
to battery terminal 606 and a power terminal coupled to common node 610.
Tn operation the foot pedal 502 is placed at a convenient location for
access by the dental professional. When the dental professional wishes to
activate a dental tool controlled by the foot pedal, he or she presses on the
foot pedal 502.1 As will be understood by one of skill in the art, the foot
pedal
is mechanically coupled to a wiper of the variable resistor 602. Moving the
wiper over the internal resistance element of the variable resistor forms a
continuously varying voltage divider. The voltage output at terminal 61G
depends on the voltage of battery G08 and the relative resistances of the
portions of resistor G02 above and below the wiper.
Tlle result, at terminal 61G, is a continuously varying voltage, having a
value at any particular moment that is related to the activation of the foot
pedal at that par ticular moment. This voltage at terminal 616 is applied to
the
input G18 of voltage controlled oscillator G20. In response to the voltage at
terminal G1G at a particular moment, the voltage controlled oscillator
produces a corresponding output signal at output 622. The output signal has
a frequency with an instantaneous value corresponding to the voltage at
terminal 61G, which is related to the degree to which pedal 502 is depressed.
This output signal is amplified in amplifier 626, RF modulated in modulator
G34, RF amplified in amplifier 644 and broadcast via antenna 648. Because the
RF modulated signal broadcast by antenna 648 contains a continuously
varying signal that may be extracted by receiver, a dental instrument coupled
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to receiver may be controlled in continuous fashion. For example, a rotary
drill may be controlled from a stopped state continuously to a state of
maximum rotation. In another example, and ultrasonic sealer may be
controlled from a stopped continuously to a state of maximum vibration in
amplitude and/or frequency.
Figure 14 shows a tr ansmitter circuit 700, accor ding to a fur ther
embodiment of the invention, in block diagram form. In the embodiment of
figure 14, a foot pedal 502 is operatively coupled to a mechanical input of a
digital encoder device 702. The digital encoder 702 includes ,a first power
terminal 704 coupled, for example, to a first battery terminal 706 of an
electrochemical battery 708 and a second power terminal 710 coupled to a
common node (such as a grounded node) 712.
I
Tlle battery 708 includes a second battery terminal 714 coupled to the
common node 712. In the illustrated embodiment, the digital encoder
pr oduces a pulse train signal at a first output por t 716 and a second sense
signal at a second output port 718. The first 716 and second 718 output ports
are coupled to respective third X20 and fourth 722 input ports of a digital
up/down counter 724. A fifth parallel output port ~2G of the digital up/down
counter 724 is adapted to output a digital count value in parallel format.
The parallel output por t 726 is coupled to a parallel input port 728 of a
modem circuit 730. The modem circuit X30 includes a parallel to digital shift
register adapted to convert a parallel count value received from the digital
up/down counter 724 into a serial bit-stream. In addition, in various
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embodiments the modem circuit 730 includes additional devices adapted to
insert control bits such as stop and start bits into a serial bit stream
output
from a serial OutpLlt por t X32 of the modem circuit 730.
Tlle modem circuit 730 also includes first 758 and second 759 clock
inputs. Clock inputs 758 and X59 are signalingly coupled to respective clock
outputs of a clock and control circuit X61. Clock signals received from the
clock and control circuit 761 control the latching of parallel data at input
port
X28 and the subsequent serial output of that data at output port 732.
In the illustrated embodiment, the serial output port 732 is coupled to
an input port 734 of a signal amplifier X36. An output 738 of the signal
amplifier 736 is coupled to a low-frequency input 738. A high frequency
input 742 of the modulator circuit 740 is coupled to an output 744 of an RF
oscillator 746.
A modulated signal output 748 of the modulator cir cuit 740 is coupled
to an input X50 of an RF axriplifier 752. An output 754 of amplifier 752 is
coupled to an antenna 754 and, through a ballast circuit 756, to common node
712 and thus to ground.
Power is supplied to the digital encoder 702, the digital up/down
counter 726, tile modem circuit X30, the signal amplifier 736, the modulation
cir cuit 740, the RF oscillator 746, and the RF amplifier 752 by way of
respective power terminals, each coupled to battery terminal X06, and ground
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terminals, each mutually coupled to the common node 712 (and thus to
battery terminal 714).
Figure 15 shows an exemplary foot pedal device 760 such as would be
employed in various embodiments of the invention. The foot pedal device 760
includes a foot pedal 502, a rotary encoder disk 762, an integrated sensor
module 764 with a pulse train output 720 and a sense output 722. As is
known in the art, tile integrated sensor module may include, for example, an
optical source and an optical detector, along with a Schmidt trigger and
amplification circuitry. In other embodiment, the integrated sensor module
may include a magnetic sensor such as a Hall effect sensor. The pedal device
760 also includes a rack X66 and pinon 768 mechanism adapted to rotate the '
rotary encoder disk 762 in a first direction 770 as the foot pedal 502 is
progressively depressed, and in a second direction X72 as the foot pedal 502
is
progressively released.
Figure 16 shows a further exemplary foot pedal device 780. Like foot
pedal device 760, foot battle device 780 includes a foot pedal 502, an
integrated sensor module X64 with a pulse train output 720 a~ld a sense
output 722. Unlike foot pedal device 760, foot pedal device 780 includes a
linear encoder grating 782 instead of a rotary encoder disk.
One of skill in the art will appreciate that the foregoing disclosure
teaches a variety of alternative embodiments including such alternative
position and motion transducers as, for example, rotary resolver devices,
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linear resolver devices, ultrasonic position measuring devices and linear Hall
effect magnetic position measuring devices, among others.
Figure 17 shows a signal transmitter 800, including a microprocessor,
5 according to another further embodiment of the invention. As illustrated,
signal transmitter 800 includes a plurality of pushbutton switches. These
pushbutton switches may be mechanically coupled to a corresponding
plug ality output switches, or to a combination of foot and hand switches,
according to various exemplary embodiments of the invention. The
10 pushbuttons include a first pushbutton 802, a second pushbutton 804, a
third
pushbutton 806, a fourth pushbutton 808, and a fifth pushbutton 810.
Pushhuttort 802 is adapted to increase the speed, power, or other
operating par ameter of a dental tool with which the signal tr ansmitter 800
15 communicates. Pushbutton 804 is adapted to reduce the speed, power, or
other operating parameter of the dental tool. Pushbutton 806 is adapted to
immediately reduce to zero the power, or other operating parameter of the
dental tool. Pushbutton 808 is adapted to turn on a light, water jet, air jet,
or
other ancillary feattue of the dental tool and pushbutton 810 is adapted to
20 turn off the light, water jet, air jet, or other and slurry feat-tire of
the denfal
tool.
Each pushbuttan 802, 804, 806, 808, 810 includes a first terminal
mutually coupled to an output node 812 of a power control device 813 . A
25 second terminal of each pushbutton is coupled to a respective input
terminal
814, 816, 818, 820, 822 of an I/O port device 824. The Ii0 port device 824
also
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includes an output terminal 826, a power supply terminal 828 and a port 830
(typically a parallel port) for receiving and sending data and control
signals.
The signal transmitter 800 also includes a microprocessor 832 with a
power supply terminal 834 arid a port 836 (typically a parallel port) for
receiving and sending data and control signals.
A data and control bus 838 is mutually coupled between data and
control por t 830 and data and control port 836. In addition, data and control
bus 838 is coupled to a data and control port 840 of a memory device such a
read-only memory device 842. In the illustrated embodiment, the memory
device also includes a power supply terminal 844. The power supply
terminal 844 is mutually coupled with a power supply terminal 834 of the
microprocessor 832, with the power supply terminal 828 of the I/O port 824,
and with the output node 812 of the power control device 813.
In the illustrated embodiment, output terminal 826 of I/O port device
824 is coupled to an input 846 of a buffer amplifier 848. An output 850 of
buffer amplifier 848 is coupled to a first input 852 of a modulation circuit
854.
A second input 856 of modulation circuit 854 is coupled to a output 858 of an
RF oscillator 860. The modulation circuit 854 includes an output 862 coupled
to an input 864 of an RF amplifier 8G6. The RF amplifier 866 leas an output
868 coupled to an antenna 8~0. The output 868 of the RF amplifier 866 is also
coupled to an input 872 of an antenna ballast 874. According to one
embodiment of the invention, the antenna ballast 874 also includes a terminal
876 coupled to a sour ce of ground potential.
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When foot pedal 502 is depressed, it causes a digital pulse train to be
sent from the optical encoder 702 to the up/down counter 724. The pulses of
this digital pulse train are counted by the counter, which increments were
decrements a count value that it maintains internally. On a periodic basis, as
determined by the clock/controller 761 this count is converted from parallel
to
serie form by the multiplexer 730. This serial digital signal is used by
modulator 740 to RF modulate an RF carrier signal produced by RF oscillator
746. The resulting RF modulated signal is amplified by amplifier 752 and
broadcast via antenna 754.
Figure 18 shows a wireless receiver 900, in block diagram form,
according to one embodiment of the invention. As illustrated, the wireless
r eceiver 900 includes a power supply 902. The power supply 902 includes a
first power terminal 904 and a second power terminal 906. The second power
terminal 906 is coupled to a common node 908. According to one
embodiment of the invention, the second common node 908 is coupled to a
source of ground potential.
An antenna 910 is coupled to a first input 912 of a preamplifier circuit
914. The preamplifier circuit 914 includes an output 916 coupled to an input
918 of a demodulator circuit 920. According to one aspect of the invention,
tile d~ modulator circuit 920 includes an RF oscillator and is adapted to
extract
a modulation signal from and amplified RF signal received from the antenna
910 by way of the preamplifier circuit 914.
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An output 922 of the demodulator circuit 920 is coupled to a serial
input 924 of a demultiplexer circuit 926. In addition, in a typical embodiment
the demultiplexer circuit 926 itzeludes a serial input parallel output shift
register along with control circuitry adapted to detect and interpret
ancillary
bits such as star t and stop bits. The demultiplexer circuit 926 also includes
a
clock input 928 and a parallel digital output 930.
The parallel digital output 930 of the demultiplexer circuit 926 is
coupled to a parallel digital input 932 of a digital to analog converter 934.
The
digital to analog converter 934 includes a clock input 936 and an analog
output 938.
A clock and control device 929 includes a first clock output 931 coupled
to clock input 928 and a second clock output 933 coupled to clock input 936.
The analog output 938 is coupled to an input 940 of a power control
circuit 942. According to one embodiment of the invention, the power control
circuit is a linear power amplifier, or a switched power amplifier adapted to
control the drill motor of a rotary electric dental tool. According to another
embodiment of the invention, the power contr of circuit is coupled to an
ultrasonic power supply, including an ultrasonic oscillator and power
amplifier. The ultrasonic power supply is adapted to control an ultrasonic
dental tool. According to a further embodiment, an output of the power
control circuit 942 is coupled to an input 944 of a dental tool 946 such as an
electric rotary dental drill. According to one embodiment of the invention,
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the electric rotary dental drill also includes a further terminal 947 coupled
to
the common node 908.
In a further aspect, according to one embodiment, the invention
includes a further digital output 948 of the demultiplexer circuit 926. The
further digital output 948 is coupled to an input 950 of a buffer amplifier
952.
The buffer amplifier 952 leas an output 954 coupled to a first terminal 956 of
a
solenoid valve activation coil 958. A second terminal 960 of the solenoid
valve activation coil 958 is coupled to common node 908. The solenoid valve
activation coil 958 is magnetically coupled to a valve 962, such as a water
control valve or air control valve.
In a further aspect of the invention, po~%ver terminal 904 of power
supply 902 is coupled to respective power input of the preamplifier 914, the
demodulator 920, the clock and control device 929, the demultiplexer 926, the
digital to analog converter 934, the power control circuit 942 and the buffer
amplifier 952. In like fashion, respective brown terminals of the preamplifier
914, the demodulator 920, the clock and control device 929, the demultiplexer
926, the digital to analog convey ter 934, the power control circuit 942 and
the
buffer amplifier 952 are coupled to common node 908.
Figure 19 shows a wireless receiver 1000 according to another
embodiment of the invention. The wireless receiver 1000 of figure 19 is
adapted to control both a mechanical tool portion of a dental instrument and
a light source associated with the dental instrument. Accordingly, the
wireless receiver 1000 includes a power supply 1002 with a power output
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1004. The power output 1004 is coupled to a power input 1006 of a wireless
receiving device 1008. An antenna 1010 is coupled to an antenna input 1012
of the receiving device 1008. A power output 1014 of the receiving device
1008 is coupled to a power input 1016 of a motor 1018, such as a rotational
5 motor or a vibratory motor, of the dental tool. The power output 1014 of the
r eceiving device 1008 is also coupled to an input 1020 of a voltage modifying
device 1022.
In the illustrated embodiment, the voltage modifying device 1022 is a
10 voltage divider including a first resistor 1024 and a second resistor 1026.
An
i
output of the voltage modifying device 1022 includes a node 1028 between the
two resistors 1024 and 1026. Node 1028 is electrically coupled to an input
1030 of a light source 1032, such as a light emitting diode, or an array of
light
emitting diodes. The light emitting diode 1032, the motor 1018, the voltage
15 modifying circuit 1022, the wireless receiving device 1008, and the power
supply 1002 all include a mutual connection to a common node 1034.
According to one embodiment of the invention, the common node 1034 is
maintained at ground potential.
20 It should be noted that the wireless receiver 1000 is best adapted to be
used with a dental instrument where simple on-off control of the rnator 1018
is required. Under such circumstances, the electrical potential maintained at
the output 1014 of the wireless receiving device 1008 may be either zero
Volts,
or a substantially constant non-zero voltage. Under such circumstances, the
25 illumination produced by the light source 1032 also will be substantially
constant. Alternately, where stepped or continuously varying control of the
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motor 1018 is desired, it is appropriate to provide a separate controlled
power
source for the light source 1032. Figure 20 shows one exemplary embodiment
of such an arrangement.
Figure 20 illustrates a wireless control circuit receiver 1050 according to
still another embodiment of the invention. Like wireless receiver 1000,
wireless receiver 1050 includes a power supply 1002 a motor 1018 and a light
sour ce 1032.
Unlike wireless receiver 1000, however, wireless receiver 1050 includes
a separate controlled power supply for the light source. In the illustrated
embodiment, this power supply is an electrochemical battery 1052. A first
terminal of the electrochemical battery is connected to a common or ground
node. A second terminal 1056 of tile battery 1052 is coupled to an input 1054
of a control device 1058.
According to one embodiment of the invention, the control device
1058 includes a switching transistor. According to another embodiment of the
invention, the control device 1058 includes an elects omechanical relay. The
control device 1058 includes a control input 1060 adapted to receive an
electrical signal. In response to the electrical signal received at control
input
1060, an output terminal 1062 is electrically connected to or disconnected
from
input terminal 1054. Output terminal 1052 is coupled to an input of a light
sour ce, such as the illustr aced light emitting diode 1032. Consequently,
whether the light emitting diode 1032 is illuminated or dark depends on a
state of tile signal received at control input 1060. Furthermore, because the
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light emitting diode 1032 has at its power source battery 1052, the
illumination provided by the diode 1032 remains substantially invariant as
the power supplied to the motor 1018 is varied.
Figure 21 shows, in block diagram form, still another example of a
wireless receiver 1100 for control of a dental instrument according to the
invention. In wireless receiver 1100, a configuration similar to that of
wireless
receiver 900 (as shown in figure 18) is used to control both a mechanical
transducer and a light source.
Like wireless receiver 900, wireless receiver 1100 includes a power
supply 902, an antenna 910, a preamplifier circuit 914, a demodulator circuit
920, a demultiplexer circuit 926, a clock and control device 929, a digital to
analog converter 934, a power control circuit 942 and a dental tool 946 such
as
an electric rotary dental drill or an ultrasonic vibrational dental sealer.
As illustrated, the multiplexes circuit 926 includes a digital output 948.
The digital output 948 is coupled to an input 1102 of a drives or device 1104.
The drives or device is electrically coupled to the power supply 902, from
which it receives electrical power, and includes an output coupled to a light
source such as a light emitting diode 1104.
The wireless receiver 1100 is adapted to receive a radiofrequency signal
and, based on the information content of that radiofrequency signal, control a
level of electrical power delivered by drive cis cuit 942 to the dental tool
946
and also control an on or off state of light source 1104.
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Wireless receiver 1150, as shown in figure 22, is also similar ilz some
aspects to wireless receiver 900. Like wireless receiver 900, wireless
receiver
1100 includes a power supply 902, an antenna 910, a preamplifier circuit 914,
a demodulator circuit 920, a demultiplexer circuit 926, a clock and control
device 929, a digital to analog converter 934, a power control circuit 942 and
a
dental tool 946 such as an electric rotary dental drill or an ultrasonic
vibrational dental sealer. In wireless receiver 1150, however, no separate
digital signal is provided for control of the light source. Instead, a light
sour ce 1152 is electrically coupled to an electric generator 1154. The
electric
generator 1154 is, in turn, mechanically coupled to an electromechanical
transducer of the dental tool 946.
For example, the electric generator 1154 may include a piezoelectric
generator mechanically coupled to a piezoelectric transducer of the dental
tool 946 and adapted to receive mechanical power therefrom. In this way, a
portion of the electrical energy transmitted from the power conhol circuit to
the dental tool 946 is converted Lay the dental tool 946 into mechanical
energy,
and then converted bacle into electrical energy for the purpose of powering
the light source 1152.
Figures 20 and 22 show the light source having a separate power
supply.
A wireless control means for the selective energizing of the light
supply source can be separate or the same as the wireless means that controls
the on and off state of the mechanical transducer of the dental tool. If a
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separate control is used, it can also be located within easy reach of the
operator to permit turn-on and/or hirn-off of the light supply sour ce through
simple foot pedal control provided within a remote control unit.
In particular, Figure 22 shows the light source drawing its power from
the ultrasonic vibrations of the ultrasonic transducer, as described in patent
application serial number 10/879,554 entitled "Ultrasonic dental tool having a
light source", incorporated herein by reference. By way of example, a
transducer such as and/or including an illumination ener gy coil is provided
and attached to the light source such that the light source is energized using
vibe ational ener gy converted by the transdwcer.
According to one embodiment of the invention, the activation of the
ultrasonic insert is controlled by the wireless foot control (110 as shown
e.g.,
in Figure 1 above). Depressing the foot control will result in activation of
the
ultrasonic handpiece, the light source and also delivery of cooling water to
the
insert tip. When the foot is removed from the foot control, the ulhasonic
handpiece as well as the light source and water are shut off.
Figure 23 shows a further embodiment of a wireless receiver 1160
according to the invention. In this embodiment the receiver 1160 includes a
microprocessor 1162. The microprocessor is coupled to a data and control bus
1164. The data and control bus is, in hun to coupled to receive circuit 1166
and, for example, a read only memory 1168. The data and control bus is also
coupled to an I/O port device 1168. The I/O port device 1168, is, in turn,
coupled to first 1170, second 1172, and third 1174 driver circuits.
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Tile first driver circuit 1170 is coupled to an electromechanical
transducer 1176, such as a motor, or piezoelectric oscillator, as would be
founded a dental instrument. The second driver circuit 1172 is coupled to a
light source 1178, such as an incandescent light, a fluorescent light, a light
emitting diode, or a combination thereof. The third driver circuit 114 is
coupled, for example, to a coil of a solenoid valve. The solenoid valve
controls a mass transfer function such as, for example an air jet, a waterjet,
or
a saliva vacuum.
One of skill in the art will understand that a dental office may be an
electrically noisy environment, especially when ultrasonic equipment is being
used. One advantage of incorporating a microprocessor in tile wireless
transmitter, as shown in figure 17 and/or the wireless receiver as shown in
figure 22 is it simplifies the transmission of more complex and complete
information between the actuator device and the dental instrument being
control. .This allows, for example, error-checking and confirmation codes that
prevent accidental activation of the dental tool in response to spurious
radiofrequency or other signals.
The use of a microprocessor or microcontroller also allows automatic
timing of tool activities, automatic adjustment of light levels, and other
automatic features desirable to a dental professional. For example, it is
possible to control various tools with a single foot pedal based on mutual
communications between the foot pedal device and a sensor, such as a finger
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switch or capacitive sensor, in the tool indicating that it is presently being
used.
The various receivers and transmitters discussed above have been
presented as embodiments employiizg radiofrequency signals for
communication. It will be understood by one of skill in the art, however, that
other signaling means, including optical signaling and audio signaling (such
as ultrasonic signaling) may be employed to good effect.
While this invention is described in detail with reference to a
certain preferred embodiments, it should be appreciated that the present
invention is not limited to those precise embodiments. Rather, in view of the
present disclosure which describes the current best mode for practicing the
invention, many modifications and variations would present themselves to
those of skill in the ar t without departing from tile scope and spirit of
this
invention.
What is claimed is:
