IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`Al-Ali et al.
`In re Patent of:
`7,761,127
`U.S. Patent No.:
`July 20, 2010
`Issue Date:
`Appl. Serial No.: 11/366,209
`Filing Date:
`March 1, 2006
`Title:
`MULTIPLE WAVELENGTH SENSOR SUBSTRATE
`
`Attorney Docket No.: 50095-00046IP1
`
`DECLARATION OF BRIAN W. ANTHONY, Ph.D.
`
`(Yamada Grounds)
`
`1
`
`APPLE 1003
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`

`

`TABLE OF CONTENTS
`
`V.
`
`
`Background .................................................................................................. 10
`I.
`Level of Ordinary Skill in the Art ............................................................... 17
`II.
`Interpretations of the ’127 Patent Claims at Issue ....................................... 18
`III.
`IV. Overview of the Prior Art ............................................................................ 18
`A. Yamada ............................................................................................. 18
`B.
`Chadwick ........................................................................................... 21
`C.
`Leibowitz ........................................................................................... 23
`D.
`Cheung .............................................................................................. 25
`E.
`Noguchi ............................................................................................. 26
`The Yamada-Chadwick Combination ......................................................... 29
`A. Overview of Combination ................................................................. 29
`B.
`Analysis ............................................................................................. 35
`1.
`Claim 7 .................................................................................... 35
`2.
`Claim 8 .................................................................................... 45
`3.
`Claim 9 .................................................................................... 46
`4.
`Claim 10 .................................................................................. 46
`VI. The Yamada-Chadwick-Leibowitz Combination ........................................ 47
`A. Overview of the Combination ........................................................... 47
`B.
`Analysis ............................................................................................. 50
`1.
`Claim 11 .................................................................................. 50
`2.
`Claim 12 .................................................................................. 52
`VII. The Yamada-Chadwick-Cheung Combination ........................................... 53
`A. Overview of the Combination ........................................................... 53
`B.
`Analysis ............................................................................................. 56
`1.
`Claim 13 .................................................................................. 56
`2.
`Claim 14 .................................................................................. 62
`3.
`Claim 15 .................................................................................. 63
`
`2
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`

`

`Claim 16 .................................................................................. 64
`4.
`Claim 17 .................................................................................. 65
`5.
`Claim 20 .................................................................................. 65
`6.
`Claim 21 .................................................................................. 67
`7.
`Claim 22 .................................................................................. 67
`8.
`Claim 23 .................................................................................. 68
`9.
`VIII. The Yamada-Chadwick-Cheung-Leibowitz Combination .......................... 69
`A. Overview of the Combination ........................................................... 69
`B.
`Analysis ............................................................................................. 69
`1.
`Claim 18 .................................................................................. 69
`2.
`Claim 19 .................................................................................. 70
`3.
`Claim 24 .................................................................................. 70
`4.
`Claim 25 .................................................................................. 70
`IX. The Yamada-Chadwick-Noguchi Combination .......................................... 71
`A. Overview of the Combination ........................................................... 71
`B.
`Analysis ............................................................................................. 74
`1.
`Claim 1 .................................................................................... 75
`2.
`Claim 2 .................................................................................... 78
`3.
`Claim 3 .................................................................................... 78
`4.
`Claim 6 .................................................................................... 79
`5.
`Claim 7 .................................................................................... 79
`6.
`Claim 8 .................................................................................... 81
`7.
`Claim 9 .................................................................................... 82
`8.
`Claim 10 .................................................................................. 82
`9.
`Claim 26 .................................................................................. 82
`10. Claim 27 .................................................................................. 84
`11. Claim 30 .................................................................................. 84
`The Yamada-Chadwick-Noguchi-Leibowitz Combination ........................ 84
`A. Overview of the Combination ........................................................... 84
`
`X.
`
`3
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`

`

`B.
`
`Analysis ............................................................................................. 85
`1.
`Claim 4 .................................................................................... 85
`2.
`Claim 5 .................................................................................... 85
`3.
`Claim 11 .................................................................................. 86
`4.
`Claim 12 .................................................................................. 86
`5.
`Claim 28 .................................................................................. 86
`6.
`Claim 29 .................................................................................. 87
`XI. Yamada Alone and in Combinations with Leibowitz, Cheung,
`and Noguchi ................................................................................................. 87
`XII. Legal Principles ........................................................................................... 92
`A. Anticipation ....................................................................................... 92
`B.
`Obviousness ...................................................................................... 93
`XIII. Conclusion ................................................................................................... 95
`
`
`
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`
`
`4
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`

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`I, Brian W. Anthony, of Cambridge, MA, declare that:
`
` My name is Dr. Brian W. Anthony. I am an Associate Principal
`
`Research Scientist at the Institute of Medical Engineering & Science at
`
`Massachusetts Institute of Technology (MIT). I am also a Principal Research
`
`Scientist at MIT’s Mechanical Engineering department, Director of the Master of
`
`Engineering in Advanced Manufacturing and Design Program at MIT, Director of
`
`Health Technology at the MIT Center for Clinical and Translational Research, a
`
`Co-Director of the Medical Electronic Device Realization Center of the Institute of
`
`Medical Engineering & Science, and Associate Director of MIT.nano. My current
`
`curriculum vitae is attached, and some highlights follow.
`
`
`
`I earned my B.S. in Engineering (1994) from Carnegie Mellon
`
`University. I earned my M.S. (1998) and Ph.D. (2006) in Engineering from MIT.
`
`My research focused on high-performance computation, signal processing, and
`
`electro-mechanical system design.
`
`
`
`In 1997, I co-founded Xcitex Inc., a company that specialized in
`
`video-acquisition and motion-analysis software. I served as the Chief Technology
`
`Officer and directed and managed product development until 2006. Our first demo
`
`product was an optical ring for human motion measurement used to capture user
`
`hand motion in order to control the user’s interaction with a computer. Many of
`
`the structural elements of our optical ring addressed the same system issues as
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`those described and claimed in the patent at issue. For example, our optical ring
`
`included multiple light emitting diodes, multiple photodetectors, techniques for
`
`modulation and synchronization, and noise reduction algorithms. We estimated
`
`human hand-motion based on how that motion changed the detected light. In our
`
`application, we did not try to eliminate motion artifact, we tried to measure it. In
`
`developing our ring, we considered well-known problems such as ambient light
`
`and noise. Motion Integrated Data Acquisition System (MiDAS) was our flagship
`
`video and data acquisition product which relied upon precise synchronization of
`
`multiple clocks for optical sensor and video acquisition, data acquisition, and
`
`external illumination.
`
`
`
`I joined MIT in 2006 and was the Director of the Master of
`
`Engineering in Advance Manufacturing and Design Program for over ten years.
`
`The degree program covers four main components: Manufacturing Physics,
`
`Manufacturing Systems, Product Design, and Business Fundamentals. Many of
`
`the courses, projects, and papers my students undertake involve technologies
`
`relevant to the patent at issue, for example, sensor devices including non-invasive
`
`optical biosensors.
`
`
`
`In 2011, I co-founded MIT’s Medical Electronic Device Realization
`
`Center (“MEDRC”) and currently serve as co-director. The MEDRC aims to
`
`create and deploy revolutionary medical technologies by collaborating with
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`clinicians, the microelectronics, and medical devices industries. We combine
`
`expertise in computation; communications; optical, electrical, and ultrasound
`
`sensing technologies; and consumer electronics. We focus on the usability and
`
`productivity of medical devices using, for example, image and signal processing
`
`combined with intelligent computer systems to enhance practitioners’ diagnostic
`
`intuition. Our research portfolio includes low power integrated circuits and
`
`systems, big data, micro electro-mechanical systems, bioelectronics, sensors, and
`
`microfluidics. Specific areas of innovation include wearable, non-invasive and
`
`minimally invasive optical biosensor devices, medical imaging, laboratory
`
`instrumentation, and the data communication from these devices and instruments
`
`to healthcare providers and caregivers. My experience with these devices is
`
`directly applicable to the technology in the patent at issue.
`
`
`
`I am currently the Co-Director of the Device Realization Lab at the
`
`Medical Electronic Device Realization Center at the Institute of Medical
`
`Engineering & Science at MIT. The Device Realization Lab designs instruments
`
`and techniques to sense and control physical systems. Medical devices and
`
`manufacturing inspection systems are a particular focus. We develop and combine
`
`electromechanical systems, complex algorithms, and computation systems to
`
`create instruments and measurement solutions for problems that are otherwise
`
`intractable.
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`7
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`
`
`The research of the Device Realization Lab focuses on product
`
`development interests cross the boundaries of computer vision, acoustic and
`
`ultrasonic imaging, large-scale computation and simulation, optimization,
`
`metrology, autonomous systems, and robotics. We use computation, and computer
`
`science, as methodology for attacking complex instrumentation problems. My
`
`work combines mathematical modeling, simulation, optimization, and
`
`experimental observations, to develop instruments and measurement solutions.
`
` My record of professional service includes recognitions from several
`
`professional organizations in my field of expertise.
`
`
`
`I am a named inventor on 10 issued U.S. patents. Most but not all of
`
`these patents involve physiological monitoring and other measurement
`
`technologies.
`
`
`
`I have published approximately 100 papers, and have received a
`
`number of best paper and distinguished paper awards. A number of papers that I
`
`have published relate to physiological monitoring and other measurement and
`
`instrumentation technologies.
`
`
`
`I have been retained on behalf of Apple Inc. to offer technical
`
`opinions relating to U.S. Patent No. 7,761,127 (“the ’127 Patent,” EX1001) and
`
`prior art references relating to its subject matter. I have reviewed the ’127 Patent
`
`and relevant excerpts of the prosecution history of the ’127 Patent (EX1002). I
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`8
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`

`have also reviewed the following prior art references and materials, in addition to
`
`other materials I cite in my declaration:
`
`• Certified English Translation of Japanese Patent Publication No. JP 2004-
`337605 A (“Yamada,” EX1004)
`
`• U.S. Patent No. 3,514,538 to Chadwick et al. (“Chadwick,” EX1005)
`
`• U.S. Patent No. 4,591,659 to Leibowitz et al. (“Leibowitz,” EX1006)
`
`• U.S. Patent No. 5,259,381 to Cheung et al. (“Cheung,” EX1007)
`
`• U.S. Patent No. 5,334,916 to Noguchi et al. (“Noguchi,” EX1008)
`
`• U.S. Patent Publication No. 2003/0033102 (“Dietiker,” EX1009)
`
`• U.S. Patent Publication No. 2005/0279949 (“Oldham,” EX1010)
`
`• J.A. Scarlett, The Multilayer Printed Circuit Board Handbook (1985)
`(selected excerpts) (EX1014)
`
`
` Counsel has informed me that I should consider these materials
`
`through the lens of one of ordinary skill in the art related to the ’127 Patent at the
`
`time of the earliest possible priority date of the ’127 Patent, and I have done so
`
`during my review of these materials. The application leading to the ’127 Patent
`
`was filed on March 1, 2006 and claims the benefit of priority to four provisional
`
`applications, all filed March 1, 2005 (the “Critical Date”). Counsel has informed
`
`me that the Critical Date represents the earliest priority date to which the
`
`challenged claims of ’127 Patent are entitled, and I have therefore used that
`
`Critical Date in my analysis below.
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`
`
`I have no financial interest in the party or in the outcome of this
`
`proceeding. I am being compensated for my work as an expert on an hourly basis.
`
`My compensation is not dependent on the outcome of these proceedings or the
`
`content of my opinions.
`
`
`
`In writing this Declaration, I have considered the following: my own
`
`knowledge and experience, including my work experience in the fields of
`
`mechanical engineering, computer science, biomedical engineering, and electrical
`
`engineering; my experience in teaching those subjects; and my experience in
`
`working with others involved in those fields. In addition, I have analyzed various
`
`publications and materials, in addition to other materials I cite in my declaration.
`
` My opinions, as explained below, are based on my education,
`
`experience, and expertise in the fields relating to the ’127 Patent. Unless otherwise
`
`stated, my testimony below refers to the knowledge of one of ordinary skill in the
`
`fields as of the Critical Date, or before. Any figures that appear within this
`
`document have been prepared with the assistance of Counsel and reflect my
`
`understanding of the ’127 Patent and the prior art discussed below.
`
`I.
`
`Background
` The ’127 patent, entitled “Multiple Wavelength Sensor Substrate,”
`
`generally describes a “physiological sensor” that emits light towards a
`
`measurement site on a patient, and measures physiological parameters such as
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`blood oxygen saturation or pulse rate. EX1001, Abstract, 2:49-65. The sensor
`
`includes “emitter” components (e.g., light emitting diodes (LEDs)) used to emit
`
`light into the measurement site, “detector” components (e.g., photodiodes,
`
`phototransistors) that detect the reflected light and provide a corresponding signal
`
`to a processor or other component representing the intensity of the reflected light,
`
`and a “temperature sensor [] thermally coupled” to the emitters such that the
`
`wavelengths of the emitted light “are determinable as a function of the drive
`
`currents” and a “bulk temperature” of the emitters. Id., Abstract. Measurements
`
`obtained with the sensors are dependent on the wavelengths of the emitted light,
`
`which can vary as a function of both drive current and temperature. According to
`
`the ‘127 Patent, measurement accuracy can be improved by tightly controlling the
`
`wavelengths of emitted light or compensating for spectral shifts in the wavelengths
`
`of emitted light due to changes in temperature, drive current, or other factors.
`
`Figure 6 shows an example assembly 500 that includes “multiple light emitting
`
`diodes (LEDs) 710” arranged on a substrate 1200:
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`11
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`

`
`
`EX1001, FIG. 6; 6:47-63 (annotated)
`
` The specification discloses that the substrate 1200 comprises a
`
`“thermal mass … disposed proximate the emitters 710 so as to stabilize a bulk
`
`temperature 1202 for the emitters.” Id., 10:22-31, FIG. 12. “A temperature sensor
`
`1230 is thermally coupled to the thermal mass 1220, wherein the temperature
`
`sensor 1230 provides a temperature sensor output 1232 responsive to the bulk
`
`temperature 1202 …” Id. Figure 12 illustrates an embodiment in which (i) light
`
`emitters 710 are positioned on one side of substrate 1200 / thermal mass 1220 and
`
`(ii) temperature sensor 1230 [is] positioned on the other side:
`
`12
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`

`

`EX1001, FIG. 12
`
`
`
` Figures 14 depicts an additional embodiment of a substrate 1200 with
`
`a thermal mass 1220. Id., 11:5-15, FIG. 14. In this embodiment, substrate 1200
`
`includes “a component layer 1401, inner layers 1402-1405 and a solder layer
`
`1406.” Id., 11:8-10. “The inner layers 1402-1405, e.g. inner layer 1402 (FIG. 18),
`
`have substantial metallized areas 1411 that provide a thermal mass 1220 (FIG. 12)
`
`to stabilize a bulk temperature for the emitter array 700 (FIG. 12).” Id. 11:10-13.
`
`13
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`

`

`EX1001, FIG. 14 (annotated)
`
`
`
`Independent claims 1, 7, and 13 of the ’127 patent are representative
`
`
`
`of the features described above:
`
`1. A physiological sensor comprising:
`
`a plurality of emitters configured to transmit optical radiation
`
`having a plurality of wavelengths in response to a corresponding
`
`plurality of drive currents, the plurality of emitters including a
`
`substrate;
`
`a thermal mass disposed proximate the emitters and within the
`
`substrate so as to stabilize a bulk temperature for the emitters; and
`
`a temperature sensor thermally coupled to the thermal mass,
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`14
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`wherein the temperature sensor provides a temperature sensor
`
`output responsive to the bulk temperature so that the wavelengths
`
`are determinable as a function of the drive currents and the bulk
`
`temperature.
`
`
`
`7. A physiological sensor capable of emitting light into tissue
`
`and producing an output signal usable to determine one or more
`
`physiological parameters of a patient, the physiological sensor
`
`comprising:
`
`a thermal mass;
`
`a plurality of light emitting sources, including a substrate of
`
`the plurality of light emitting sources, thermally coupled to the
`
`thermal mass, the sources having a corresponding plurality of
`
`operating wavelengths, the thermal mass disposed within the
`
`substrate;
`
`a temperature sensor thermally coupled to the thermal mass
`
`and capable of determining a bulk temperature for the thermal
`
`mass, the operating wavelengths dependent on the bulk
`
`temperature; and
`
`15
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`a detector capable of detecting light emitted by the light
`
`emitting sources after tissue attenuation, wherein the detector is
`
`capable of outputting a signal usable to determine one or more
`
`physiological parameters of a patient based upon the operating
`
`wavelengths.
`
`
`
`13.
`
`In a physiological sensor adapted
`
`to determine a
`
`physiological parameter using a plurality of light emitting sources
`
`with emission wavelengths affected by one or more dynamic
`
`operating parameters, a sensor method comprising:
`
`providing a thermal mass disposed within the substrate
`
`proximate the light emitting sources and a temperature sensor
`
`thermally coupled to the thermal mass;
`
`transmitting optical radiation from the plurality of light
`
`emitting sources into body tissue;
`
`detecting the optical radiation after tissue attenuation; and
`
`determining a plurality of operating wavelengths of the light
`
`emitting sources dependent on a bulk temperature of the light
`
`emitting sources so that one or more physiological parameters of
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`16
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`

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`a patient can be determined based upon
`
`the operating
`
`wavelengths.
`
`
`
`II. Level of Ordinary Skill in the Art
` Based on the foregoing and upon my experience in this area, a person
`
`of ordinary skill in the art as of the Critical Date of the ’127 patent (a “POSITA”)
`
`would have had a Bachelor of Science degree in an academic discipline
`
`emphasizing the design of electrical and thermal technologies, in combination with
`
`training or at least one to two years of related work experience with the capture and
`
`processing of data or information, including physiological monitoring
`
`technologies. Alternatively, a POSITA could have had a Master of Science degree
`
`in a relevant academic discipline with less than a year of related work experience
`
`in the same discipline.
`
` Based on my experiences, I have a good understanding of the
`
`capabilities of a POSITA. Indeed, I have taught, participated in organizations, and
`
`worked closely with many such persons over the course of my career.
`
`
`
`I have performed my analysis through the lens of a POSITA as of the
`
`Critical Date.
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`III.
`
`Interpretations of the ’127 Patent Claims at Issue
`
`I understand that, for purposes of my analysis in this inter partes
`
`review proceeding, the terms appearing in the patent claims should generally be
`
`interpreted according to their “ordinary and customary meaning.” See Phillips v.
`
`AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc). I understand that
`
`“the ordinary and customary meaning of a claim term is the meaning that the term
`
`would have to a person of ordinary skill in the art in question at the time of the
`
`invention.” Id. at 1313. I also understand that the person of ordinary skill in the
`
`art is deemed to read the claim term not only in the context of the particular claim
`
`in which the disputed term appears, but in the context of the entire patent,
`
`including the specification. Id.
`
`IV. Overview of the Prior Art
`A. Yamada
` Yamada describes an optical sensor that “detects light (reflected light)
`
`that has been directed toward the surface of the human body, scattered inside the
`
`human body, and returned toward the exposed surface.” EX1004, [0001]-[0002].
`
`An example of such an optical sensor is a pulse oximeter used to measure the
`
`oxygen saturation of blood. Id. Other uses can include measurement of blood
`
`glucose or measurement of sugar content in food produce. EX1004, [0106].
`
` Yamada recognized a problem with prior optical sensors “in that the
`
`LED used to emit light also generates heat, and the patient is exposed to this heat
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`because the optical sensor is attached to the surface of a fingernail.” Id., [0005].
`
`“As a result, the exposure time and power consumption (that is, the amount of light
`
`generated) have to be limited in order to suppress the amount of heat that is
`
`generated.” Id. To overcome this issue, Yamada proposed a design for an optical
`
`sensor that was intended to reduce the amount of heat to which the subject wearing
`
`the device is exposed. Id., [0001]-[0005]. This optical sensor disclosed in Yamada
`
`includes “a light emitting unit 11 (including LEDs 111, 112), a light receiving unit
`
`12, a main body 13, an optical passage 14,” and a “reflecting unit 131.” EX1004,
`
`[0042]-[0043], [0068], FIG. 5. The LEDs 111, 112 are disposed on a first surface
`
`of substrate 15, while the light receiving unit 12 is disposed on an opposite surface
`
`of the same substrate 15. Id. In this embodiment, light emitted from the LEDs
`
`111, 112 is reflected by the reflecting unit 131 and guided through optical passage
`
`14 to the measurement site (e.g., the surface of a finger) via end portion 141. Id.,
`
`[0059]-[0062]. A portion of the light emitted to the measurement site is scattered
`
`and reflected back toward the light receiving unit 12. Id.
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`
`
`EX1004, FIG. 5 (annotated)
`
` Yamada further describes how the board/substrate 15 “may have heat
`
`transferring properties that guide heat generated by the light emitting unit toward
`
`the outside.” EX1004, [0020]. In some embodiments, a “heat conductor 132” is
`
`“connected to the board 15 near the light emitting unit 11” to allow heat to be
`
`transmitted away from the light emitting unit. Id., [0102]-[0103]. In further
`
`embodiments, “the board 15 is composed of a first substrate 151, a second
`
`substrate 152, and an intermediate layer 153.” Id., [0080]-[0084], FIG. 19. The
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`20
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`intermediate layer 153 can be “made of a conductive material” such as “copper,
`
`aluminum, gold, [or] conductive resins.” Id., [0083].
`
`EX1004, FIG. 19 (annotated)
`
`
`
` Additionally, Yamada teaches that a “temperature sensor” can be
`
`attached to the optical probe in each embodiment. This temperature sensor can be
`
`positioned, for example, on the lower surface of the board 15 facing the user, or
`
`attached to the upper surface of the board 15 facing away from the user. EX1004,
`
`[0109]-[0110]. “When the temperature of the optical probe 1 is monitored using a
`
`temperature sensor, a warning can be issued when the temperature becomes too
`
`high or emission of light from the light emitting unit 11 can be stopped.” Id.,
`
`[0111].
`
`B. Chadwick
` Chadwick is a decades old patent—filed in November 1968—that
`
`teaches the long-established practice of constructing printed circuit boards (PCBs)
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`with a metallic core for thermal management. See EX1005. As explained in
`
`Chadwick, “[a]lthough circuit boards possesses of a core comprising a sheet of
`
`naturally electrically nonconducting material have been widely used and have been
`
`highly effective, they lack the desirable property of being capable of quickly and
`
`effectively dissipating heat which is generated by components in the circuit when
`
`the apparatus in which they are used is operated.” Id, 1:35-44. Chadwick further
`
`explains that the need for more effective heat dissipation had become particularly
`
`acute, “as circuits and components have become smaller, … in that connection of
`
`the components and circuits into increasingly smaller spaces diminishes the
`
`amount of space available around them for the circulation of cooling air whereby
`
`to keep the temperature of the electrical apparatus when operating at a desirable
`
`minimum.” Id., 1:44-52.
`
` To achieve improved thermal performance, Chadwick proposed “[a]
`
`metal core printed circuit board which includes multiple layers of synthetic plastic
`
`resin material on a sheet of metal.” Id., 1:14-16. An example of an embodiment of
`
`such a PCB is shown in Figure 11, which comprises a metal sheet 10 on which
`
`layers of material have been applied to form a substrate for the mounting of
`
`electronic components:
`
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`

`
`
`EX1005, FIG. 11 (annotated)
`
` Chadwick’s metal core 10 provides a substantial heat sink capable of
`
`absorbing heat from components on the surface of the PCB. To encourage heat
`
`transfer between surface components and the metal core 10, the intermediate layers
`
`include electrically non-conductive but thermally conductive material. EX1005,
`
`4:11-38; generally id., 2:2-29, 4:39-8:17 (describing detailed process for the
`
`formation of layers on metal core 10).
`
`C. Leibowitz
` Leibowitz, a U.S. patent filed in 1983, describes “a multilayered
`
`printed circuit board structure in which multiple layers of graphite are employed …
`
`to provide enhanced thermal conductivity.” EX1006, 2:30-34. Leibowitz
`
`recognized that “as larger numbers of components are mounted on circuit boards,
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`… the heat produced by the components must be dissipated in some manner,” but
`
`“[s]ince the principal materials used in circuit boards are insulators, the boards
`
`have traditionally played no significant role in dissipating heat from the
`
`components that they support.” EX1006, 1:56-64. To address this, and other
`
`problems with traditional circuit boards, Leibowitz proposed a multilayer PCB
`
`having “good thermal conduction properties to enhance conduction from devices
`
`mounted on the board.” Id., 2:24-27.
`
` Figure 2 illustrates an embodiment of Leibowitz’s PCB. As shown
`
`below, Leibowitz’s “circuit board 10 includes a plurality of layers of graphite 16
`
`interleaved between layers 18 of a dielectric material,” where “[s]ome of the layers
`
`18 are copper coated, as indicated at 20.” Id., 3:56-61. “The PTFE
`
`[polytetrafluoroethylene] layers 18 provide the basic dielectric material of the
`
`board 10, and the graphite layers 16 provide both thermal conductivity and control
`
`of thermal coefficient of expansion.” Id., 3:61-65.
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`EX1006, FIG. 2 (annotated)
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`D. Cheung
` Like Yamada, Cheung addresses the impact of temperature
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`fluctuations in optical probes for oximetry devices. Cheung is specifically
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`concerned with, among other things, “compensating for the effect temperature
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`variations have on the wavelength of light emitted by the oximeter sensor light
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`source (40, 42).” EX1007, Abstract. “Because current oximetry techniques are
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`dependent upon the wavelengths of light emitted by the LEDs (40, 42), the
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`wavelengths must be known.” Id. “Even when predetermined combinations of
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`LEDs (40, 42) having relatively precise wavelengths are employed, variations in
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`the wavelength of light emitted may result.” Id.
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`25
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` Further, Cheung teaches that “[b]ecause the sensor (12) may be
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`exposed to a significant range of temperatures while in use, the effect of
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`temperature on the wavelengths may be significant.” Id. “To compensate for this
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`effect, a temperature sensor (50) is included in the sensor (12) to produce a signal
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`indicative of sensor temperature.” Id. “This signal is interpreted by the oximeter
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`circuitry including, for example, a microcomputer (16), where the effect of
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`temperature on wavelength is compensated for.” Id. In particular, the temperature
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`sensor signal “allows microcomputer 16 to accurately determine the wavelengths
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`of the light emitted by LEDs 40 and 42 and subsequently produce an accurate
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`determination of oxygen saturation.” Id., 13:25-33; generally id., 12:7-14:2, FIGS.
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`10-11 (detailed descriptions of sensor assembly 48).
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`E. Noguchi
` Noguchi teaches techniques for “controlling the emission spectrum of
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`an LED with high precision,” including determining the wavelength of light
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`emitted by the LED based on (1) a measured temperature and (2) a measured level
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`of current or voltage driving the LED. EX1008, 1:7-12, 2:50-3:14, 1:33-50. For
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`example, Noguchi explains the following:
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`The temperature of the LED itself or the
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`surrounding ambient temperature and the driving
`power of the LED are detected. Then, the emission
`wavelength energy can be calculated by subtracting
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`26
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`the value of an applied power multiple by a
`specified coefficient and the difference from the
`standard
`temperature multiple by a specified
`coefficient from the optical band gap at the standard
`temperature.
`EX1008, 2:2-10 (emphasis added)
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` Noguchi explains how “[t]he temperature of the LED is measured by
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`a temperature sensor,” although “the temperature to be measured is not limited to
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`the temperature of the LED itself, but the temperature in the environment
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`surrounding the LED can also be measured.” EX1006, 2:20-29. Furthermore,
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`“[t]he number of LEDs or sensors used in the present invention can be more than
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`one each.” Id., 2:30-41.
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` Figure 1 is a block diagram of an example system for “LED emissi