`
`EXHIBIT
`
`EXHIBIT
`DSS-2005
`
`DSS-2 005
`
`

`
`United States Patent
`(12) United States Patent
`(12)
`Loftin et al.
`Loftin et a].
`
`(10) Patent N0.:
`(10) Patent No.:
`(45) Date of Patent:
`(45) Date of Patent:
`
`US 7,092,762 B1
`US 7,092,762 B1
`Aug. 15, 2006
`Aug. 15,2006
`
`US007092762Bl
`US007092762B1
`
`(54) LOW-POWER, HIGH-MODULATION-INDEX
`(54) LOW-POWER, HIGH-MODULATION-INDEX
`AMPLIFIER FOR USE IN
`AMPLIFIER FOR USE IN
`BATTERY-POWERED DEVICE
`BATTERY-POWERED DEVICE
`
`(75) Inventors: Scott M Loftin, Simi Valley, CA (US);
`(75)
`Inventors: Scott M Loftin, Simi Valley, CA (US);
`Kelly H McClure Simi Valley C A
`Kelly H McClure, Simi Valley, CA
`’
`’
`(US)
`(Us)
`
`(73) Assignee: Advanced Bionics Corporation,
`(73) Assignee: Advanced Bionics Corporation,
`Valencia, CA (US)
`valencla’ CA (Us)
`
`( * ) Notice:
`( * ) Not1ce:
`
`.
`
`.
`
`.
`
`.
`
`Subject to any disclaimer, the term of this
`Subject' to any d1scla1mer,the term of this
`patent is extended or adjusted under 35
`patent 1s extended or adjusted under 35
`U.S.C. 154(b) by 613 days.
`U.S.C. 154(b) by 613 days.
`
`.
`
`(21) Appl. No.: 10/445,121
`21 A l. N .: 10/445 121
`(
`)
`pp
`0
`’
`(22) Filed:
`May 23, 2003
`(22)
`Filed:
`May 23, 2003
`
`Related US. Application Data
`Related U.S. Application Data
`
`(62) Division of application No. 09/945,303, filed on Aug.
`(62) Division of application No_ 09/945,303’ ?led on Aug
`31, 2001, now Pat. No. 6,591,139.
`31, 2001, now Pat NO_ 6,591,139
`_
`_
`_
`_
`(60) Provisional application No. 60/230,399, filed on Sep.
`(60) Provlslonal apphcanon NO‘ 60/230’399’ ?led on Sep'
`6, 2000.
`6’ 2000'
`I t Cl
`51
`Int. Cl.
`(51)
`2006 01
`(
`) An6}N /02
`(2006.01)
`A61N 1/02
`(2006'01)
`H04B 5/00
`(2006.01)
`H04B 5/00
`_
`_
`_
`(
`'
`)
`(52) U.S. Cl.
`........................ ..
`607/60; 607/156; 607/32;
`(52) US. Cl. ........................ .. 607/60, 607/156, 607/32,
`128/903; 128/902
`_
`_
`_
`128/903’ 128/902
`(58) Field of Classification Search ................ .. 607/60,
`(58) Field of Classi?cation Search ................ .. 607/ 60,
`607/32, 156, 61; 128/902, 903; 340/870.01;
`607/32> 156: 61; 128/902’ 903; 340/87001;
`455/41.1, 41.2
`_
`_
`455(41~1> 41-2
`See application file for complete search history.
`See apphcanon ?le for Complete Search hlstory-
`R f
`Ct d
`References Cited
`e erences 1 e
`U.S. PATENT DOCUMENTS
`U.S. PATENT DOCUMENTS
`4,223,679 A
`9/1980 Schulman et al.
`i *
`15101111111?“ e; 3}‘
`455/41 1
`4,441,210 A *
`4/1984 Hochmair et al.
`....... .. 455/41.1
`4,571,589 A
`2/1986 Slocum et al.
`4’57l’589 A
`21986 slzccumagt 21 a ' """" "
`'
`5,193,539 A
`3/1993 Schulman et al.
`5’l93’539 A
`3 / 1993 Schulman et'al
`5,193,540 A
`3/1993 Schulman et al.
`5,193,540 A
`3/1993 Schulman et al.
`5,697,076 A
`12/1997 Troyk et al.
`5,697,076 A 12/1997 Troyk et a1.
`
`(56)
`(56)
`
`4/1998 Chen et al.
`5,741,316 A
`4/1998 Chen et a1.
`5,741,316 A
`6/1998 Grevious et al.
`5,766,232 A
`6/1998 Grevious et al.
`5,766,232 A
`9/1999 Mann
`5,948,006 A
`9/1999 Mann
`5,948,006 A
`4/2000 Mueller et al.
`6,047,214 A
`4/2000 Mueller et al.
`6,047,214 A
`6/2000 Griifith
`6,073,050 A
`6/2000 Gnfi?th
`6’073’050 A
`8/2000 Christopherson et al.
`6,099,479 A
`8/2000 Chrlstopherson et al.
`6,099,479 A
`12/2000 Thompson
`6,163,721 A
`6,163,721 A 12/2000 Thompson
`6,185,452 B1
`2/2001 Schulman et al.
`6,185,452 B1
`2/2001 Schulman et al.
`FOREIGN PATENT DOCUMENTS
`FOREIGN PATENT DOCUMENTS
`W0 98/43700
`8/1998
`WO 98/43700
`8/1998
`W0 98/37926
`9/1998
`W0 98/43701
`10/1998
`WO 98/43701
`“M998
`
`WO 98/37926
`
`9/1998
`
`W0
`W0
`W0
`W0
`W0
`
`W0
`
`* cited by examiner
`* Cited by examiner
`Primary Examiner—Kennedy Schaetzle
`Primar ExamineriKenned SchaetZle
`y
`y
`(74) Attorney, Agent, or Firm—Bryant R. Gold; Victoria A.
`(74) Attorney, Agent, or F irmiBryant R. Gold; Victoria A.
`Poissant
`P01558111‘
`
`ABSTRACT
`(57)
`ABSTRACT
`(57)
`An external transmitter circuit drives an implantable neural
`An external transmitter circuit drives an implantable neural
`stimulator having an implanted coil from a primary coil
`stimulator having an implanted coil from a primary coil
`driven by a power amplifier. For efficient power consump-
`driven by a poWer ampli?er. For ef?cient poWer consump
`tion, the transmitter output circuit (Which includes the pri
`tion, the transmitter output circuit (which includes the pri-
`mary coil driven by the poWer ampli?er inductively coupled
`mary coil driven by the power amplifier inductively coupled
`with the implanted coil) operates as a tuned resonant circuit.
`With the implanted coil) operates as a tuned resonant circuit.
`When operating as a tuned resonant circuit, it is difficult to
`When operating as a tuned resonant circuit, it is dif?cult to
`modulate the carrier signal with data having sharp rise and
`modulate the carrier signal With data having sharp rise and
`fall times without using a high power modulation amplifier.
`fall times Without using a high poWer modulation ampli?er.
`Sharp rise and fall times are needed in order to ensure
`Sharp rise and fall times are needed in Order to ensure
`reliable data transmission. To overcome this difficulty, the
`reliable data transmission. To overcome this dif?culty, the
`present invention includes an output switch that selectively
`present invention includes an Output Switch that Selectively
`inserts a resistor in the transmitter output coil circuit in order
`inserts a resistor in the transmitter output coil circuit in order
`to de-tune the resonant circuit only during those times when
`to de-tune the resonant circuit only during those times When
`data modulation is needed. Such de-tuning alloWs sharp rise
`data modulation is needed. Such de-tuning allows sharp rise
`and fall times in the data modulation without the need for
`and fall times in the data modulation Without the need for
`using a high power modulation amplifier. Because data
`using a high poWer modulation ampli?er. Because data
`modulation is typically needed for only a small percent of
`modulation is typically needed for only a small percent of
`the time that a carrier signal is present, it is thus possible
`the time that a carrier signal is present, it is thus possible
`using the present invention to achieve reliable data modu-
`using the present invention to achieve reliable data modu
`lation, transmission and reception without having to use a
`lation, transmission and reception Without having to use a
`high power modulation amplifier in the transmitter.
`high poWer modulation ampli?er in the transmitter.
`
`7 Claims, 4 Drawing Sheets
`7 Claims, 4 Drawing Sheets
`
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`U.S. Patent
`U.S. Patent
`
`Aug. 15, 2006
`Aug. 15,2006
`
`Sheet 1 of4
`Sheet 1 of4
`
`US 7,092,762 B1
`US 7,092,762 B1
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`
`U.S. Patent
`U.S. Patent
`
`Aug. 15, 2006
`Aug. 15,2006
`
`Sheet 2 of4
`Sheet 2 of4
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`US 7,092,762 B1
`US 7,092,762 B1
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`U.S. Patent
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`
`Aug. 15,2006
`Aug. 15,2006
`
`Sheet 3 of4
`Sheet 3 0f 4
`
`US 7,092,762 B1
`US 7,092,762 B1
`
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`

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`U.S. Patent
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`US 7,092,762 B1
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`US 7,092,762 B1
`US 7,092,762 B1
`
`1
`1
`LOW-POWER, HIGH-MODULATION-INDEX
`LOW-POWER, HIGH-MODULATION-INDEX
`AMPLIFIER FOR USE IN
`AMPLIFIER FOR USE IN
`BATTERY-POWERED DEVICE
`BATTERY-POWERED DEVICE
`
`The present application is a Divisional of U.S. application 5
`The present application is a Divisional of US. application
`Ser. No. 09/945,303, filed Aug. 31, 2001 now U.S. Pat. No.
`Ser. No. 09/945,303, ?led Aug. 31, 2001 now US. Pat. No.
`6,591,139; which claims the benefit of U.S. Provisional
`6,591,139; Which claims the bene?t of US. Provisional
`Application Ser. No. 60/230,399, filed Sep. 6, 2000, which
`Application Ser. No. 60/230,399, ?led Sep. 6, 2000, Which
`applications are incorporated herein by reference.
`applications are incorporated herein by reference.
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`
`The present invention relates to modulation amplifiers,
`The present invention relates to modulation ampli?ers,
`and more particularly to a low-power, high-modulation-
`and more particularly to a loW-poWer, high-modulation
`index amplifier suitable for use in battery-powered devices,
`index ampli?er suitable for use in battery-poWered devices,
`e.g., an implantable battery-powered medical device.
`e.g., an implantable battery-poWered medical device.
`Modulation is the process of varying some characteristic
`Modulation is the process of varying some characteristic
`of one wave in accordance with another wave. In radio
`of one Wave in accordance With another Wave. In radio
`broadcasting, for example, some stations use amplitude
`broadcasting, for example, some stations use amplitude
`modulation (AM), while other stations use frequency modu-
`modulation (AM), While other stations use frequency modu
`lation (FM). In television, the video portion of the program
`lation (PM). In television, the video portion of the program
`is amplitude modulated and the audio portion is frequency
`is amplitude modulated and the audio portion is frequency
`modulation. In other types of transmissions, such as are used
`modulation. In other types of transmissions, such as are used
`with satellite transmissions or transmissions to and from an
`With satellite transmissions or transmissions to and from an
`implantable medical device, some sort of digital modulation
`implantable medical device, some sort of digital modulation
`is typically employed, e.g., pulse-amplitude, pulse-code,
`is typically employed, e.g., pulse-arnplitude, pulse-code,
`pulse-duration, pulse-frequency, pulse-position, or pulse
`pulse-duration, pulse-frequency, pulse-position, or pulse-
`time modulation. These types of digital modulation are
`time modulation. These types of digital modulation are
`typically employed to convey binary bit information, e.g.,
`typically employed to convey binary bit information, e.g.,
`strings of 1’s and 0’s, arranged in words and bytes.
`strings of 1’s and 0’s, arranged in Words and bytes.
`A class of small implantable medical devices is known in
`A class of small implantable medical devices is knoWn in
`the art that comprises tiny microstimulators and/or sensors.
`the art that comprises tiny microstimulators and/or sensors.
`These tiny microstimulators or sensors, which are hereafter
`These tiny microstimulators or sensors, Which are hereafter
`referred to as BIONTM devices, are described more fully,
`referred to as BIONTM devices, are described more fully,
`e.g., in U.S. Pat. Nos. 5,193,539; 5,193,540 and PCT Pub-
`e.g., in US. Pat. Nos. 5,193,539; 5,193,540 and PCT Pub
`lications WO 98/37926; WO 98/43700 and WO 98/43701,
`lications WO 98/37926; WO 98/43700 and WO 98/43701,
`each of which patents or publications are incorporated
`each of Which patents or publications are incorporated
`herein by reference. Advantageously, the BION devices are
`herein by reference. Advantageously, the BION devices are
`generally small enough to be implanted in a minimally
`generally small enough to be implanted in a minimally
`invasive manner through the lumen of a needle, or a similar-
`invasive manner through the lumen of a needle, or a similar
`sized cannula.
`siZed cannula.
`It has been discovered that the sharpness (rise time and/or
`It has been discovered that the sharpness (rise time and/or
`fall time) of the pulsed modulation used with the BION
`fall time) of the pulsed modulation used With the BION
`device has a direct affect on the reliability of the operation
`device has a direct affect on the reliability of the operation
`of the BION device, and more particularly on the ability of
`of the BION device, and more particularly on the ability of
`the BION device to properly decode and validate com-
`the BION device to properly decode and validate com
`mands. Disadvantageously,
`the sharp rise times and fall
`mands. Disadvantageously, the sharp rise times and fall
`times of the pulsed modulation signals needed for reliable
`times of the pulsed modulation signals needed for reliable
`operation of a BION-type device have heretofore required
`operation of a BION-type device have heretofore required
`the use of high power modulation amplifiers. High power
`the use of high poWer modulation ampli?ers. High poWer
`modulation amplifiers, in turn, are not compatible with the
`modulation ampli?ers, in turn, are not compatible With the
`low power requirements of an implantable medical device
`loW poWer requirements of an implantable medical device
`systems, particularly systems that include battery-powered
`systems, particularly systems that include battery-powered
`devices. There is thus a need in the art for a low power
`devices. There is thus a need in the art for a loW poWer
`modulation amplifier having sharp rise/fall times that may
`modulation ampli?er having sharp rise/fall times that may
`be used within an implantable device system, such as a
`be used Within an implantable device system, such as a
`system that uses the BION device described in the refer-
`system that uses the BION device described in the refer
`enced patents and patent applications.
`enced patents and patent applications.
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`
`10
`
`15
`
`20
`20
`
`25
`25
`
`30
`30
`
`35
`35
`
`40
`40
`
`45
`45
`
`50
`50
`
`55
`55
`
`The present
`invention addresses the above and other
`The present invention addresses the above and other
`needs by providing an external transmitter circuit that drives
`needs by providing an external transmitter circuit that drives
`an implantable BION device, or other implantable neural
`an implantable BION device, or other implantable neural
`stimulator, from a primary coil driven by a power amplifier.
`stimulator, from a primary coil driven by a poWer ampli?er.
`For efficient power consumption,
`the transmitter output
`For ef?cient poWer consumption, the transmitter output
`circuit (which includes the primary coil driven by the power
`circuit (Which includes the primary coil driven by the poWer
`amplifier
`inductively coupled with an implanted coil
`ampli?er inductively coupled With an implanted coil
`included as part of the implantable BION device) operates as
`included as part of the implantable BION device) operates as
`a tuned resonant circuit. Disadvantageously, when operating
`a tuned resonant circuit. Disadvantageously, When operating
`
`60
`60
`
`65
`65
`
`2
`2
`as a tuned resonant circuit, it is difficult to modulate the
`as a tuned resonant circuit, it is di?icult to modulate the
`carrier signal with data having sharp rise and fall times
`carrier signal With data having sharp rise and fall times
`without using a high power modulation amplifier. In order to
`Without using a high poWer modulation ampli?er. In order to
`overcome this difficulty, the present invention includes an
`overcome this dif?culty, the present invention includes an
`output switch that selectively inserts a resistor in the trans-
`output sWitch that selectively inserts a resistor in the trans
`mitter output coil circuit in order to de-tune the resonant
`mitter output coil circuit in order to de-tune the resonant
`circuit only when data modulation is needed. Such de-tuning
`circuit only When data modulation is needed. Such de-tuning
`allows sharp rise and fall
`times in the data modulation
`alloWs sharp rise and fall times in the data modulation
`without the need for using a high power modulation ampli-
`Without the need for using a high poWer modulation ampli
`fier. Advantageously, because the data modulation is typi-
`?er. Advantageously, because the data modulation is typi
`cally needed for only a very small percent of the time that
`cally needed for only a very small percent of the time that
`a carrier signal is present, e.g., 2—4%,
`it is thus possible
`a carrier signal is present, e.g., 244%, it is thus possible
`using the present invention to achieve reliable data modu-
`using the present invention to achieve reliable data modu
`lation,
`transmission and reception within the implanted
`lation, transmission and reception Within the implanted
`BION (or other) neural simulation device without having to
`BION (or other) neural simulation device Without having to
`use a high power modulation amplifier in the transmitter.
`use a high poWer modulation ampli?er in the transmitter.
`In accordance with one aspect of the invention, there is
`In accordance With one aspect of the invention, there is
`provided an implantable medical device, such as an implant-
`provided an implantable medical device, such as an implant
`able neural stimulator, having an implanted coil through
`able neural stimulator, having an implanted coil through
`which an extemally-generated carrier signal,
`transmitted
`Which an extemally-generated carrier signal, transmitted
`from an external primary coil, may be inductively received.
`from an external primary coil, may be inductively received.
`The carrier signal is modulated with data at a low duty cycle,
`The carrier signal is modulated With data at a loW duty cycle,
`e.g., 4% or less, in order to transfer control data into the
`e.g., 4% or less, in order to transfer control data into the
`implantable medical device. The carrier signal provides
`implantable medical device. The carrier signal provides
`operating power for the implantable device, either directly
`operating poWer for the implantable device, either directly
`by continuously supplying operating poWer, or indirectly by
`by continuously supplying operating power, or indirectly by
`supplying power on an as-needed basis to recharge a
`supplying poWer on an as-needed basis to recharge a
`rechargeable battery housed within the implantable medical
`rechargeable battery housed Within the implantable medical
`device. The carrier signal, when not modulated with data
`device. The carrier signal, When not modulated With data
`(which is typically most of the time, e.g., 96% or more), is
`(Which is typically most of the time, e.g., 96% or more), is
`inductively coupled to the implant coil through a high Q
`inductively coupled to the implant coil through a high Q
`resonant circuit, e.g., a resonant circuit having a Q greater
`resonant circuit, e.g., a resonant circuit having a Q greater
`than about 10. The high Q resonant circuit includes the
`than about 10. The high Q resonant circuit includes the
`primary coil and the implant coil. Such high Q resonant
`primary coil and the implant coil. Such high Q resonant
`circuit promotes the efficient transfer of power into the
`circuit promotes the ef?cient transfer of poWer into the
`implantable medical device. A switch selectively connects a
`implantable medical device. A sWitch selectively connects a
`resistor in circuit relationship with the external coil
`to
`resistor in circuit relationship With the external coil to
`de-tune the tuned resonant circuit when the carrier signal is
`de-tune the tuned resonant circuit When the carrier signal is
`modulated with data (which is typically a very small percent
`modulated With data (Which is typically a very small percent
`of the time). Such de-tuning advantageously lowers of the Q
`of the time). Such de-tuning advantageously loWers of the Q
`of the resonant circuit to about four or less, and allows the
`of the resonant circuit to about four or less, and alloWs the
`data modulation to have sharper rise and fall times at lower
`data modulation to have sharper rise and fall times at loWer
`power transmission levels. The sharper rise and fall times, in
`poWer transmission levels. The sharper rise and fall times, in
`turn, allow more reliable data communication to occur with
`turn, alloW more reliable data communication to occur With
`the implantable medical device.
`the implantable medical device.
`One embodiment of the invention may be characterized as
`One embodiment of the invention may be characterized as
`an implantable medical device system comprising: (1) an
`an implantable medical device system comprising: (1) an
`external power amplifier having a primary coil;
`(2) an
`external poWer ampli?er having a primary coil; (2) an
`implant device having an implanted coil; (3) means within
`implant device having an implanted coil; (3) means Within
`the power amplifier for generating a carrier signal that is
`the poWer ampli?er for generating a carrier signal that is
`inductively coupled from the primary coil to the implanted
`inductively coupled from the primary coil to the implanted
`coil through a high Q resonant circuit (Qé 10) that includes
`coil through a high Q resonant circuit (Q; 10) that includes
`the primary coil and the implanted coil; (4) means within the
`the primary coil and the implanted coil; (4) means Within the
`power amplifier for modulating the carrier signal with data;
`poWer ampli?er for modulating the carrier signal With data;
`(5) a resistor and a switch within the power amplifier,
`(5) a resistor and a sWitch Within the poWer ampli?er,
`wherein the resistor is connected to the primary coil through
`Wherein the resistor is connected to the primary coil through
`the switch, and wherein the resistor, when connected to the
`the sWitch, and Wherein the resistor, When connected to the
`primary coil, de-tunes the high Q resonant circuit (Q§4);
`primary coil, de-tunes the high Q resonant circuit (Q24);
`and (6) means within the power amplifier for operating the
`and (6) means Within the poWer ampli?er for operating the
`switch to de-tune the resonant circuit when the carrier signal
`sWitch to de-tune the resonant circuit When the carrier signal
`is modulated with data, wherein the de-tuned resonant
`is modulated With data, Wherein the de-tuned resonant
`circuit allows the data modulation of the carrier signal to
`circuit alloWs the data modulation of the carrier signal to
`occur with sharper rise and fall times, which sharper rise and
`occur With sharper rise and fall times, Which sharper rise and
`fall times, in turn, are more reliably detected as data within
`fall times, in turn, are more reliably detected as data Within
`the implant device.
`the implant device.
`Another embodiment of the invention may be viewed as
`Another embodiment of the invention may be vieWed as
`a low power modulation amplifier that comprises: (1) an
`a loW poWer modulation ampli?er that comprises: (1) an
`amplifier having an output port; (2) a first capacitor (C1)
`ampli?er having an output port; (2) a ?rst capacitor (C1)
`connected between the output port of the amplifier and a
`connected betWeen the output port of the ampli?er and a
`voltage reference, e.g., ground; (3) an antenna coil (L1)
`voltage reference, e.g., ground; (3) an antenna coil (L1)
`
`

`
`US 7,092,762 B1
`US 7,092,762 B1
`
`3
`3
`connected to the output port of the amplifier through a
`connected to the output port of the ampli?er through a
`second capacitor (C2), the second capacitor functioning as a
`second capacitor (C2), the second capacitor functioning as a
`coupling capacitor; (4) a resistor connected to the antenna
`coupling capacitor; (4) a resistor connected to the antenna
`coil; and (5) a switch (SW1) that switchably connects the
`coil; and (5) a sWitch (SW1) that sWitchably connects the
`resistor in circuit relationship with the antenna coil.
`resistor in circuit relationship With the antenna coil.
`Yet another embodiment of the invention may be charac-
`Yet another embodiment of the invention may be charac
`terized as a method of reliably and efficiently transmitting
`terized as a method of reliably and ef?ciently transmitting
`data and power to an implantable medical device from an
`data and poWer to an implantable medical device from an
`external power amplifier. The implantable medical device
`external poWer ampli?er. The implantable medical device
`includes an implanted coil. The external power amplifier
`includes an implanted coil. The external poWer ampli?er
`includes a primary coil. The method includes the steps of:
`includes a primary coil. The method includes the steps of:
`(1) generating a carrier signal in the power amplifier; (2)
`(l) generating a carrier signal in the poWer ampli?er; (2)
`inductively coupling the carrier signal from the primary coil
`inductively coupling the carrier signal from the primary coil
`to the implanted coil through a high Q (QEIO) resonant
`to the implanted coil through a high Q (QZIO) resonant
`circuit that includes the primary coil and the implanted coil
`circuit that includes the primary coil and the implanted coil
`when only power is to be transmitted to the implantable
`When only poWer is to be transmitted to the implantable
`medical device; (3) modulating the carrier signal with data
`medical device; (3) modulating the carrier signal With data
`when data is to be transmitted to the implantable medical
`When data is to be transmitted to the implantable medical
`device; and (4) inductively coupling the modulated carrier
`device; and (4) inductively coupling the modulated carrier
`signal from the primary coil to the implanted coil through a
`signal from the primary coil to the implanted coil through a
`low Q (Q§4) resonant circuit that includes the primary coil
`loW Q (Q24) resonant circuit that includes the primary coil
`and the implanted coil. In a preferred implementation, the
`and the implanted coil. In a preferred implementation, the
`low Q circuit is obtained by electrically connecting a resistor
`loW Q circuit is obtained by electrically connecting a resistor
`to the primary coil so as to detune the high Q resonant circuit
`to the primary coil so as to detune the high Q resonant circuit
`so that it becomes a low Q circuit.
`so that it becomes a loW Q circuit.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other aspects, features and advantages of
`The above and other aspects, features and advantages of
`the present invention will be more apparent from the fol-
`the present invention Will be more apparent from the fol
`lowing more particular description thereof, presented in
`loWing more particular description thereof, presented in
`conjunction With the following drawings Wherein:
`conjunction with the following drawings wherein:
`FIG. 1 is a functional block diagram that illustrates the
`FIG. 1 is a functional block diagram that illustrates the
`main components of a system that uses an implantable
`main components of a system that uses an implantable
`BION-type device;
`BION-type device;
`FIG. 2 illustrates various signal and spectra waveforms
`FIG. 2 illustrates various signal and spectra Waveforms
`that may be used with the system of FIG. 1;
`that may be used With the system of FIG. 1;
`FIG. 3 depicts a data waveform (A) having slow or
`FIG. 3 depicts a data Waveform (A) having sloW or
`sluggish rise and fall times, which are generally not com-
`sluggish rise and fall times, Which are generally not com
`patible with reliable operation of a BION-type stimulation
`patible With reliable operation of a BION-type stimulation
`system, and a data waveform (B) having short or sharp rise
`system, and a data Waveform (B) having short or sharp rise
`and fall times, which result from use of the present inven-
`and fall times, Which result from use of the present inven
`tion, and which promote the reliable operation of a BION-
`tion, and Which promote the reliable operation of a BION
`type stimulation system;
`type stimulation system;
`FIG. 4A illustrates one embodiment of the circuitry used
`FIG. 4A illustrates one embodiment of the circuitry used
`in the external transmitter in order to implement the present
`in the external transmitter in order to implement the present
`invention;
`invention;
`FIG. 4B shows an alternative embodiment of the circuitry
`FIG. 4B shoWs an alternative embodiment of the circuitry
`of FIG. 4A; and
`of FIG. 4A; and
`FIG. 5 shows a representative schematic implementation
`FIG. 5 shoWs a representative schematic implementation
`of the circuitry of FIG. 4A.
`of the circuitry of FIG. 4A.
`Corresponding reference characters indicate correspond-
`Corresponding reference characters indicate correspond
`ing components throughout the several views of the draw-
`ing components throughout the several vieWs of the draW
`1ngs.
`ings.
`
`DETAILED DESCRIPTION OF THE
`DETAILED DESCRIPTION OF THE
`INVENTION
`INVENTION
`
`The following description is of the best mode presently
`The folloWing description is of the best mode presently
`contemplated for carrying out the invention. This descrip-
`contemplated for carrying out the invention. This descrip
`tion is not to be taken in a limiting sense, but is made merely
`tion is not to be taken in a limiting sense, but is made merely
`for the purpose of describing the general principles of the
`for the purpose of describing the general principles of the
`invention. The scope of the invention should be determined
`invention. The scope of the invention should be determined
`with reference to the claims.
`With reference to the claims.
`In order to better understand the present invention, it will
`In order to better understand the present invention, it Will
`first be helpful to provide an overview of an implantable
`?rst be helpful to provide an overvieW of an implantable
`medical device system, e.g., a neural stimulation system,
`medical device system, e.g., a neural stimulation system,
`
`10
`
`15
`
`20
`20
`
`25
`25
`
`30
`30
`
`35
`35
`
`40
`40
`
`45
`45
`
`50
`50
`
`55
`55
`
`60
`60
`
`65
`65
`
`4
`4
`with which the present invention may be used. A functional
`With Which the present invention may be used. A functional
`block diagram that illustrates the main components of such
`block diagram that illustrates the main components of such
`a system is shown in FIG. 1. As seen in FIG. 1, the system
`a system is shoWn in FIG. 1. As seen in FIG. 1, the system
`includes an implantable BION-type device 20 and one or
`includes an implantable BION-type device 20 and one or
`more external components 12 or 14. The implantable device
`more external components 12 or 14. The implantable device
`20 includes electronic circuitry 24 connected to electrodes
`20 includes electronic circuitry 24 connected to electrodes
`23a and 23b. An implanted coil 22 is also connected to the
`23a and 23b. An implanted coil 22 is also connected to the
`circuitry 24. All but the electrodes 23a and 23b are housed
`circuitry 24. All but the electrodes 23a and 23b are housed
`within an hermetically sealed case 21.
`Within an hermetically sealed case 21.
`The implantable device 20 interfaces with either an exter-
`The implantable device 20 interfaces With either an exter
`nal charger unit 12 and/or an external control unit 14 (also
`nal charger unit 12 and/or an external control unit 14 (also
`referred to as an “extemal controller”). The charger unit 12
`referred to as an “extemal controller”). The charger unit 12
`has a primary coil 1311 connected to it. It is through the
`has a primary coil 1311 connected to it. It is through the
`primary coil 1311 that the charger unit electromagnetically
`primary coil 1311 that the charger unit electromagnetically
`couples a carrier signal 15a to the implanted coil 22, and
`couples a carrier signal 15a to the implanted coil 22, and
`hence to the electrical circuitry 24 included within the
`hence to the electrical circuitry 24 included Within the
`device 20. The external controller 14 similarly has a primary
`device 20. The external controller 14 similarly has a primary
`coil 13b connected to it through which a carrier signal 15b
`coil 13b connected to it through Which a carrier signal 15b
`is coupled to the implanted coil 22 of the implantable device
`is coupled to the implanted coil 22 of the implantable device
`20.
`20.
`In operation, either the external charger 12 or the external
`In operation, either the external charger 12 or the external
`controller 14 inductively couples a carrier signal 1511 or 15b
`controller 14 inductively couples a carrier signal 1511 or 15b
`to the implanted coil 22. The implanted circuitry 22 extracts
`to the implanted coil 22. The implanted circuitry 22 extracts
`operating power from the carrier signal, e.g., through recti-
`operating poWer from the carrier signal, e.g.