US 20070l23763Al
`
`(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2007/0123763 A1
`Al-Ali et al.
`(43) Pub. Date:
`May 31, 2007
`
`(54) OPTICAL SENSOR INCLUDING
`DISPOSABLE AND REUSABLE ELEMENTS
`
`Publication Classification
`
`(76)
`
`Inventors: Ammar Al-Ali, Tustin, CA (US);
`Yassir Abdul-Hafiz, Irvine, CA (US)
`
`Correspondence Address:
`KNOBBE MARTENS OLSON & BEAR LLP
`2040 MAIN STREET
`FOURTEENTH FLOOR
`
`IRVINE, CA 92614 (US)
`
`(21) Appl. No.:
`
`11/606,455
`
`(22)
`
`Filed:
`
`Nov. 29, 2006
`
`Related U.S. Application Data
`
`(60)
`
`Provisional application No. 60/740,541, filed on Nov.
`29, 2005.
`
`(51)
`
`Int. Cl.
`(2006.01)
`A61B 5/00
`(52) U.S.Cl.
`............................................................ .. 600/344
`
`(57)
`
`ABSTRACT
`
`An embodiment of the present disclosure provides a non-
`invasive optical sensor or probe including disposable and
`reusable components. The assembly of the disposable and
`reusable components is straightforward, along with the
`disassembly thereof. During application to a measurement
`site,
`the assembled sensor
`is advantageously secured
`together while the componentry is advantageously properly
`positioned.
`
`O01
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`Apple Inc.
`APL 1 01 1
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`U.S. Patent No.
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`8,989,830
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`001
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`Apple Inc.
`APL1011
`U.S. Patent No. 8,989,830
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`

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`May 31, 2007
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`OPTICAL SENSOR INCLUDING DISPOSABLE
`AND REUSABLE ELEMENTS
`
`PRIORITY CLAIM
`
`[0001] This application claims priority benefit under 35
`U.S.C. §
`ll9(e) from U.S. Provisional Application No.
`60/740,541, filed Nov. 29, 2005, entitled “Optical Sensor
`Including Disposable and Reusable Elements.” The present
`application incorporates the foregoing disclosure herein by
`reference.
`
`REFERENCE TO RELATED APPLICATIONS
`
`[0002] This application also relates to U.S. Pat. No. 6,920,
`345, filed on Jan. 24, 2003 and issued on Jul. 19, 2005,
`entitled “Optical Sensor Including Disposable And Reusable
`Elements.” The present application also incorporates the
`foregoing disclosure herein by reference.
`
`BACKGROUND OF THE DISCLOSURE
`
`[0003]
`
`1. Field of the Disclosure
`
`[0004] The present disclosure relates to noninvasive opti-
`cal sensors capable of detecting light attenuated by body
`tissue. More specifically, the disclosure relates to the com-
`bination of reusable and disposable components of such
`sensors.
`
`[0005]
`
`2. Description of the Related Art
`
`[0006] Early detection of low blood oxygen is important in
`a wide range of applications, including patient monitoring,
`the fitness industry, home care and the like. Noninvasive
`oximetry was developed to study and to measure, among
`other things, the oxygen status of blood. Pulse oximetry—a
`noninvasive, widely accepted form of oximetry—relies on a
`sensor attached externally to a patient to output signals
`indicative of various physiological parameters, such as a
`patient’s blood oxygen saturation.
`
`[0007] A pulse oximeter sensor generally includes one or
`more energy emission devices, such as specific wavelength
`emitting LEDs, and one or more energy detection devices.
`The sensor is generally attached to a measurement site such
`as a patient’s finger, ear, ankle, or the like, using an
`attachment mechanism such as a disposable tape, reusable
`housing, a plastic or hook-and-loop fastening strap, or the
`like. The attachment mechanism positions the emitters and
`detector proximal to the measurement site such that the
`emitters project energy into the blood vessels and capillaries
`of the measurement site, which in mm attenuate the energy.
`The detector then detects that attenuated energy. The detec-
`tor communicates at
`least one signal
`indicative of the
`detected attenuated energy to a signal processing device
`such as an oximeter. The oximeter generally calculates,
`among other things, one or more physiological parameters
`of the measurement site.
`
`[0008] Noninvasive oximetry sensors can be disposable,
`reusable, or some combination thereof. Reusable sensors
`ofler advantages of superior cost savings. However, reusable
`sensors are often available in a limited number of sizes even
`
`though patient measurement sites, such as fingers or toes,
`can have a much larger size distribution. Therefore, some-
`times reusable sensors do not readily conform to each
`patient’s measurement site. Disposable sensors on the other
`
`hand offer superior conformance to the measurement area.
`However, disposable sensors are generally more costly due
`to limited use of the relatively expensive sensor components
`which could otherwise last for repeated uses.
`
`[0009] Faced with the drawbacks of reusable and dispos-
`able sensors, manufacturers began designing a number of
`middle-ground sensors. For example, some manufacturers
`ofler a reusable detector portion that couples to a disposable
`emitter portion. After a single use, the disposable emitter
`portion is detached from the reusable detector portion and
`discarded. While this design reuses some of the expensive
`electronic components, obviously others are still discarded.
`
`[0010] Another example of a middle-ground sensor
`includes a reusable “Y” type sensor, where a reusable
`emitter portion connects to one branch of the “Y” while a
`reusable detector portion connects to the other branch. A
`disposable tape positions the two branches on a measure-
`ment site. In this design, the electronics are reusable; how-
`ever, the multiple wires tend to be somewhat diflicult to
`properly attach, especially with a moving patient.
`
`[0011] Other examples of middle-ground sensors include a
`disposable tape sandwich where a reusable flexible circuit
`housing an emitter portion and a detector portion, are
`“sandwiched” between adhesive layers. Separation of such
`disposable tape sandwiches can be cumbersome. In yet
`another example of a middle-ground sensor, the Assignee of
`the present application disclosed a reusable flexible circuit
`that is snapped into a disposable tape. In an embodiment of
`that disclosure, small pegs on the flexible circuit snap into
`mechanically mating elements on the disposable tape.
`Grooves allow some longitudinal travel between the reus-
`able portion and the disposable portion, thereby allowing for
`some self adjustment between components to account for
`differences in radial attachment requirements.
`
`SUMMARY OF THE DISCLOSURE
`
`[0012] However, even with the advances discussed in the
`foregoing, there continues to be a need for a commercially
`viable, straightforward, middle-ground solution that offers
`reusability of expensive electronic components while main-
`taining some of the advantages of disposable attachment.
`
`[0013] Accordingly, one aspect of an embodiment of the
`present disclosure is to provide a sensor having reusable and
`disposable components.
`In an embodiment,
`the sensor
`advantageously includes a disposable component structured
`to provide a locking feature capable of reducing a chance
`that the disposable and reusable components can separate
`when attached or otherwise in close proximity to the body.
`In an embodiment, a locking mechanism takes advantage of
`longitudinal displacement and engages when the reusable
`and disposable portions of the sensor are curved around the
`measurement site (such as a finger). Separation of the
`reusable portion from the disposable portion is then advan-
`tageously complicated until the sensor is removed from the
`patient and the displacement is reversed.
`
`[0014] A further aspect of an embodiment of this disclo-
`sure is that the tip of the reusable sensor component slides
`angularly into the front housing component on the dispos-
`able portion before sitting flat in a slot or guide. The slot or
`guide includes a rubber stop that in an embodiment advan-
`tageously provides a fluid-tight or at least fluid resistant
`contact.
`
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`In a further embodiment, a memory device or
`[0015]
`information element is provided as part of the disposable
`housing. An electrical contact is made between the memory
`device and the reusable components to, for example, ensure
`quality control in the disposable housing, provide inforrna-
`tion to the patient monitor about the type of sensor, type of
`patient, type of attachment mechanism or attachment posi-
`tion, information about operating characteristics of the sen-
`sor, product manufacture or sale history, distributor history,
`amount of use, combinations of the same or the like.
`
`[0016] For purposes of summarizing the disclosure, cer-
`tain aspects, advantages and novel features of the disclosure
`have been described herein. Of course, it is to be understood
`that not necessarily all such aspects, advantages or features
`will be embodied in any particular embodiment of the
`disclosure.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0017] The following drawings and the associated descrip-
`tions are provided to illustrate embodiments of the present
`disclosure and do not limit the scope of the claims.
`
`[0018] FIG. 1 illustrates an exemplary block diagram of an
`oximeter system including a sensor and a monitoring instru-
`ment, according to embodiments of the disclosure.
`
`[0019] FIG. 2 illustrates a perspective view of the sensor
`of FIG. 1, where reusable and disposable components of the
`sensor are separated according to an embodiment of the
`disclosure.
`
`[0020] FIGS. 3A-3B illustrate perspective views of the
`sensor of FIG. 2, where the components are connected in an
`assembly/disassembly position, according to an embodi-
`ment of the disclosure.
`
`[0021] FIG. 4 illustrates a perspective side view of the
`sensor of FIG. 2, where the components are in an attached
`position, according to an embodiment of the disclosure.
`
`[0022] FIG. 5A-SB illustrate top and bottom perspective
`views of a detector casing or housing of the reusable
`component, according to an embodiment of the disclosure.
`
`[0023] FIG. 6A-6B illustrate top and bottom perspective
`views of an emitter casing or housing of the reusable
`component, according to an embodiment of the disclosure.
`
`[0024] FIG. 7 illustrates a perspective view of a front
`holding clip of the disposable component, the clip being
`capable of mechanically mating with the detector casing of
`FIG. 5, according to an embodiment of the disclosure.
`
`[0025] FIG. 8 illustrates a perspective view of the assem-
`bly/disassembly clip of the disposable component, the clip
`being capable of mechanically mating with the emitter
`casing of FIG. 6, according to an embodiment of the
`disclosure.
`
`[0026] FIG. 9 illustrates a top planar view of the dispos-
`able component including the front holding clip and the
`assembly/disassembly clip of FIGS. 7-8, according to an
`embodiment of the disclosure.
`
`[0027] FIG. 10A illustrates an exploded view of the dis-
`posable component, according to an embodiment of the
`disclosure.
`
`FIG. 10B illustrates an exploded view of the reus-
`[0028]
`able component, according to an embodiment of the disclo-
`sure.
`
`FIG. 11 illustrates top planar and side views of
`[0029]
`component placement of conventional sensors.
`
`FIG. 12 illustrates top planar and side views of
`[0030]
`component placement according to an embodiment of the
`disclosure.
`
`FIG. 13 illustrates a top down planar view of a
`[0031]
`disposable sensor, according to an embodiment of the dis-
`closure.
`
`DETAILED DESCRIPTION
`
`[0032] An embodiment of the present disclosure is a
`sensor with a reusable component and a disposable compo-
`nent. The reusable component generally includes reusable
`expensive electronic components of a sensor, including, for
`example, the emitters and detector. In an embodiment, the
`emitters and the detector are located in respective casings
`connected by a short flexible circuit. In an embodiment, a
`disposable component includes mechanically matable por-
`tions adapted to mechanically mate with the casings of the
`reusable component. In an embodiment, the casings of the
`reusable component mate with the disposable component in
`a manner that provides an assembly/disassembly state, and
`an attached state. During the assembly/disassembly state, a
`caregiver can readily and straightforwardly assemble the
`sensor by aligning the casings on the reusable component
`and the mechanical housings of the disposable component
`and snapping them together. In an embodiment, the align-
`ment is generally vertical in nature and the snapping occurs
`by lightly pressing on the components while on a flat surface
`or supported from underneath by, for example, the hand of
`the assembler. Each detector housing generally vertically
`accepts the casings; however, one of the casings, such as, for
`example, the forward housing or clip accepts the casing in
`such a way as to keep the forward casing generally immo-
`bile.
`
`[0033] Disassembly is equally as straightforward, as the
`caregiver may advantageously lift on the reusable compo-
`nent wire, and the rearward casing extracts from the
`mechanically mated housing of the disposable element.
`Continual lifting then similarly extracts the forward casing
`from the mechanically mated housing of the disposable
`element. In an embodiment, the flexible circuit between the
`forward and rearward casing may be reinforced in order to
`withstand multiple disassembly stresses or forces occurring
`from the lifting of the reusable wire. In an embodiment,
`pressing the disposable portion onto a flat surface while
`lifting the reusable portion aids in the disassembly process.
`
`structures
`includes
`portion
`disposable
`[0034] The
`designed to attach the sensor to a measurement site. In an
`embodiment,
`the disposable portion comprises a flexible
`tape having an adhesive side capable of removably adhering
`to the measurement site.
`In an embodiment where the
`
`disposable portion wraps around a measurement site, the act
`of bending the flexible circuit advantageously causes the
`assembly/disassembly clip to recess into the mechanically
`mated portion of the disposable housing, thereby reducing
`the likelihood of disassembly during application to a mea-
`surement site. In an embodiment, the sensor components are
`
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`locked together through the longitudinal displacement of the
`clip with respect to the disposable housing. In such an
`embodiment, a stop diminishes the capacity of the clip to
`move vertically,
`thereby locking it
`into place.
`In this
`embodiment, removing the adhesive from the measurement
`site and straightening the sensor components unlocks the
`reusable and disposable components.
`
`In an embodiment, assembly also necessarily elec-
`[0035]
`trically connects electronic components of the disposable
`portion with those of the reusable portion. In an embodi-
`ment, then disposable portion includes an information ele-
`ment or memory device, such as, for example, a resistor, a
`single wire addressable memory device, such as those
`EPROMs or EEPROMs commercially available from Dallas
`Semiconductor, other memory or processing devices, com-
`binations of the same, or the like. The information element
`may include data accessibly by an attached patient monitor
`to accomplish quality control, monitor configuration, sensor
`use monitoring, combinations of the same, or the like.
`
`Still other advantages of embodiments of the
`[0036]
`present disclosure include proportionally positioning of the
`mechanically mating housings to provide for optical align-
`ment between the emitters and detector. Moreover,
`in
`embodiments including the disposable tape, the tape may
`advantageously be scored to assist the caregiver in proper
`alignment with the body tissue at the measurement site.
`
`[0037] To facilitate a complete understanding of the dis-
`closure, the remainder of the detailed description describes
`the disclosure with reference to the drawings. Correspond-
`ing parts refer to corresponding elements and the leading
`digit indicates the figure in which that element first appears.
`
`[0038] General Design
`
`[0039] FIG. 1 presents an exemplary block diagram of the
`components generally found in an oximeter sensor, accord-
`ing to an embodiment of the invention. For example, FIG. 1
`shows as oximeter system 100 including sensor 102, cable
`170, and monitor 172. The sensor 102 includes one or more
`emitters 174 for irradiating body tissue with light, and one
`or more detectors 176 capable of detecting the light after
`attenuation by the tissue. The sensor 102 also includes an
`information element 136 such as an EPROM. The sensor
`
`102 also includes a plurality of conductors communicating
`signals;
`including emitter drive signal conductors 180,
`detector composite signal conductors 182, and EPROM
`conductors 184. According to an embodiment, the sensor
`conductors 180, 182, 184 communicate their signals to and
`from the monitor 172 through cable 170.
`
`[0040] Although disclosed with reference to the cable 170,
`a skilled artisan will recognize from the disclosure herein
`that the communication to and from the sensor 106 may
`advantageously include a wide variety of cables, cable
`designs, public or private communication networks or com-
`puting systems, wired or wireless communications, combi-
`nations of the same, or the like.
`
`[0041] The information element 136 may comprise an
`EPROM, an EEPROM, combinations of the same, or the
`like. In general, the information element 136 may include a
`read-only device or a read and write device. The information
`element may advantageously also comprise a resistor, an
`active network, or any combination of the foregoing. The
`
`remainder of the present disclosure will refer to such pos-
`sibilities as simply an information element for ease of
`disclosure.
`
`[0042] The information element 136 may advantageously
`store some or all of a wide variety of data and information,
`including, for example, information on the type or operation
`of the sensor 104, type of patient or body tissue, buyer or
`manufacturer information, sensor characteristics including
`the number of wavelengths capable of being emitted, emitter
`specifications, emitter drive requirements, demodulation
`data, calculation mode data, calibration data, software such
`as scripts, executable code, or the like, sensor electronic
`elements, sensor life data indicating whether some or all
`sensor components have expired and should be replaced,
`encryption information, or monitor or algorithm upgrade
`instructions or data. The information element 136 may
`advantageously configure or activate the monitor, monitor
`algorithms, monitor functionality, or the like based on some
`or all of the foregoing information. For example, without
`authorized data accessibly on the information element 136,
`quality control functions may inhibit functionality of the
`monitor. Likewise, particular data may activate certain func-
`tions while keeping others inactive. For example, the data
`may indicate a number of emitter wavelengths available,
`which in turn may dictate the number and/or type of physi-
`ological parameters that can be monitored or calculated.
`
`FIG. 1 also shows the monitor 172 comprising one
`[0043]
`or more processing boards 186 communicating with one or
`more host instruments 188. According to an embodiment,
`the board 186 comprises processing circuitry arranged on
`one or more printed circuit boards capable of being installed
`in specialized monitoring equipment or distributed as an
`OEM component for a wide variety of patient monitoring
`equipment. As shown in FIG. 1, the board 186 includes a
`front end signal conditioner 190, a sensor controller 194, a
`digital signal processor or microcontroller 192, and a
`memory reader 1102. In an embodiment, the processor 192
`instructs the sensor controller 194 to output one or more
`drive signals capable of causing the emitters 174 to activate.
`The front end 190 receives detector output indicating detec-
`tion of light from the emitters 174 attenuated by body tissue
`of the measurement site. The front end 190 conditions the
`
`signal and outputs the signal and/or signal data to the
`processor 192. The processor 192 executes calculations
`adapted to determine values and/or indications or physi-
`ological parameters, trends of the parameters, alarms based
`on the parameters or the trends or combinations of trends
`and/or parameters, or the like. In addition, the reader 1102
`is capable of retrieving information stored on information
`element 136. The reader 1102 or the processor 192 may
`advantageously decrypt such information to the extent
`desired.
`
`In an embodiment, the host instrument 188, com-
`[0044]
`municates with the processor 192 to receive signals indica-
`tive of the physiological parameter information calculated
`by the processor 192. The host
`instrument preferably
`includes one or more display devices 196 capable of pro-
`viding indicia representative of the calculated physiological
`parameters of the tissue at the measurement site. Such
`display devices 196 may be controlled by a monitor con-
`troller 198 that accepts signals from processor 192. In an
`embodiment, monitor controller 198 may also accept signals
`from user interface 1100. Such signals may be indicative of
`
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`various display options for configuring the output to display
`196. In an embodiment, the host instrument 188 may advan-
`tageously be capable of displaying one or more of a pulse
`rate, plethysmograph data, perfusion quality, signal or mea-
`surement quality, values of blood constituents in body tissue,
`including for example, SpCO, functional or fractional SpO2,
`or the like. In other embodiments, the host instrument 188 is
`capable of displaying values for one or more of SpMet,
`HbO2, Hb, HbCO, HbMet, Hct, blood glucose, bilirubin, or
`the like. In still additional embodiments, the host instrument
`188 is capable of displaying trending data for one or more
`of the foregoing measured or determined data. Moreover an
`artisan will realize from the disclosure herein many display
`options for the data are available.
`
`instrument 188
`the host
`In an embodiment,
`[0045]
`includes audio or visual alarms that alert caregivers that one
`or more physiological parameters are falling below prede-
`termined safe thresholds, and may include indications of the
`confidence a caregiver should have in the displayed data. In
`further embodiment, the host instrument 188 may advanta-
`geously include circuitry capable of determining the expi-
`ration or overuse of components of the sensor 102, including
`for example, reusable elements, disposable elements, or
`combinations of the same.
`
`[0046] Although disclosed with reference to particular
`embodiment, an artisan will recognize from the disclosure
`herein many variations of the instrument 172. For example,
`in a broad sense, the instrument 172 accepts data from the
`sensor 102, determines values for one or more parameters,
`trends, alarms or the like, and outputs them to an interface
`such as a display.
`
`[0047] Sensor Configuration
`
`[0048] FIG. 2 illustrates an embodiment of sensor 102,
`having reusable component 204 and disposable component
`206. The components are shown detached. FIG. 3 shows a
`very similar perspective drawing, but with reusable compo-
`nent 204 and disposable component 206 in their attached, in
`their assembled state. Returning to FIG. 2,
`the reusable
`component 204 comprises an emitter casing 208, a detector
`casing 210, and a flexible circuit 212. The emitter casing 208
`comprises one or more emission devices operable to emit
`light at multiple wavelengths, such as red and infrared.
`Detector casing 210 houses one or more detectors, such as
`a photodiode detector. In an embodiment, a flexible circuit
`connects the emitter casing 208 and detector casing 210. In
`a preferred embodiment, the flexible circuit is housed in a
`protective cover and extends beyond the emitter casing 208.
`An artisan will understand from the disclosure herein that
`
`the emitter and detector electrical components may advan-
`tageously be housed in the casings disclosed or simply
`reversed from the foregoing disclosure. In an embodiment,
`the flexible circuit 212 and/or cabling extends significantly
`beyond the casings to advantageously remove any cable
`attachment mechanisms from the proximity of the tissue
`site.
`
`[0049] FIG. 2 also shows the disposable component 206
`including a base 214, an assembly/disassembly clip 216 and
`a front holding clip 218, the clips each adapted to accept the
`emitter casing 208 and detector casing 210, respectively. In
`the preferred embodiment, front holding clip 218 includes a
`front stop 220. Front stop 220 is advantageous for a number
`of reasons. It helps reduce the likelihood that the reusable
`
`component 102, and in particular detector casing 210, will
`slide forward in the front holding clip 218 during assembly
`or use. In addition, in an embodiment where the stop 220
`comprises rubber or other liquid resistant material, the stop
`220 provides a liquid resistant connection between the
`detector casing 210 and front holding clip 218, reducing the
`likelihood of sensor contamination and electrical shorts.
`
`Rubber or a similar material may be used in an embodiment
`to compose such a front stop 220.
`
`FIG. 3A shows detector casing 210 clipped or
`[0050]
`snapped into front holding clip 218 with a tip of the casing
`slid below a portion of the front stop 220. This allows the
`front stop 220 to reduce not only horizontal movement of the
`detector casing 210, but also helps reduce vertical release of
`the detector casing unless pulled from, for example, the
`cable. FIG. 3 also shows the front stop 220 with a generally
`rounded shape providing a relatively soft material with few,
`if any, sharp edges. Such an embodiment advantageously
`reduces damage to a patient or the sensor if the patient tries
`to scratch body tissue using the edges of the assembled
`sensor, or if the sensor is dropped, banged against something
`while worn, or the like. This is particularly useful when used
`with burn victims or other patients whose skin may damage
`easily.
`
`FIG. 3B highlights the ease of assembly. The
`[0051]
`disposable portion 206 is set on a surface or held in the one
`hand. The caregiver then aligns a front tip of casing 210 and
`guides it into front holding clip 218. This is more a vertical
`alignment with the front tip snapping below stop 220. The
`casing 210 including rounded wings 531 (FIG. 5) that
`mechanically associate with rounded side walls 739 (FIG.
`7). These mechanical structures allow the tip of casing 210
`to slide below stop 220, and snap down into place. Once
`casing 210 is in place, casing 208 aligns vertically and
`simply slides down, with tabs 262 (FIG. 6) located sliding
`into slots 222 (FIG. 8) on either side of assembly/disassem-
`bly clip 216. In an embodiment, the flexible circuit portion
`212 between the casings 208 and 210 may bulge slightly.
`
`FIG. 3B shows the emitter casing 208 after it has
`[0052]
`been slid onto assembly/disassembly clip 216. With the
`reusable sensor component 204 and the disposable sensor
`component 206 in a generally flat position,
`the emitter
`casing 208 remains vertically mobile in slots 222 of assem-
`bly/disassembly clip 216. When the sensor 102 is wrapped
`around a measurement site 426, such as a finger, as shown
`in FIG. 4, emitter casing 208 slides forward in assembly/
`disassembly clip 216 due to the tension from flexible circuit
`212 and detector casing 210 being substantially immobile in
`front holding clip 218. Tabs 262 (FIG. 6) slide away from
`slots 222 (FIG. 8) and under holding elements 224 (FIG. 8).
`Holding elements 224 prevent emitter casing 208 from
`moving vertically or further forward by restricting tabs 262.
`As stated before, the tension from flexible circuit 212 when
`it is wrapped around a measurement site 426 prevents the
`emitter casing 208 from moving horizontally backwards.
`The immobility of casing 210, combined with the tabs 262
`sliding out of alignment with slots 222, effectively secure the
`reusable sensor component 204 with respect to disposable
`component 206, with the emitters appropriately position
`with respect
`to the detector. Thus, realignment
`through
`release of tension, i.e., removing the sensor from an attach-
`ment site and straightening it out, ensure straightforward
`disassembly of the sensor components. Although shown
`
`O19
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`019
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`

`
`US 2007/0123763 Al
`
`May 31, 2007
`
`using tabs 262 and slots 222, a skilled artisan will recognize
`from the disclosure herein a wide variety of mechanical
`mechanisms that ensure reliable attachability when the sen-
`sor is applied to the tissue site and straightforward assembly/
`disassembly when the sensor is removed. For example, one
`or more detents that snap closed beyond a catch and are
`released through pinching could be used to secure the
`reusable portion 104 to the disposable portion 106.
`
`[0053] As alluded to previously, FIG. 4 depicts sensor 102
`as would be seen when in use on a measurement site 426. In
`
`this case, the measurement site is a finger, but other sites
`such as a toe, ear, wrist or ankle may also work. Disposable
`component 206 and reusable component 204 are attached,
`and reusable component 204 is
`in the assembled and
`attached position. Longitudinal tension on the flexible cir-
`cuit 212 from the differing radius between the tape and the
`circuit has pulled the emitter casing 208 forward, placing
`tabs 262 under holding elements 224. FIG. 4 shows that, in
`an embodiment, emitter casing 208 is rearward with respect
`to assembly/disassembly clip 216 when in the unattached
`position (FIG. 3B), but the front of emitter casing 208 is
`forward and in an embodiment, generally flush with assem-
`bly/disassembly clip 216 when in the attached position (FIG.
`4).
`
`[0054] FIGS. 5A-5B show close up top and bottom per-
`spective views of an embodiment of the detector casing 210.
`Electrical contact acceptors 528 are shown as insets on the
`sides of detector casing 210. In an embodiment, electrical
`contact acceptors 528 are located on either side of the
`detector casing 210 and include conductive material that
`would be connected to a wire in flexible circuit 212. Buttons
`
`530 found on either side of the detector casing 210 are, in the
`preferred embodiment, generally hemispherical protrusions
`adapted to sit in depressions 738 found on front holding clip
`218 (see FIG. 7).
`
`[0055] FIG. 7 shows a close up perspective view of an
`embodiment of the front holding clip 218, again to show
`detail less easily seen in smaller figures. While most of the
`front sensor clip 218 may be made of plastic or some other
`rigid material, the preferred embodiment has front stop 220
`made of rubber as has been discussed. Opening 732 is also
`shown here and may be a hole through front holding clip 218
`or may just be of a generally transparent material that will
`allow light from the LEDs to enter the tissue at the mea-
`surement site and allow light energy to be read by the
`photodiode. Having window 732 be transparent material
`will allow the sensor to obtain readings while keeping the
`LEDs and photodiode from becoming contaminated. Other
`optical filters or the like could also be housed in window
`732.
`
`[0056] Located inside front stop 220 are conducting
`prongs 734. Conducting prongs 734 are adapted to fit into
`electrical contact acceptors 528. In an embodiment,
`the
`conducting prongs 734 close the circuit with the information
`element 136. When the detector casing 210 clips into front
`holding clip 218,
`the conducting prongs 734 slide into
`electrical contact with acceptors 528. The completed circuit
`allows the sensor 102, and in turn an oximeter, to commu-
`nicate with information element 136. Depressions 738 are
`located on the interior of front holding clip 218. They are