Abstract:
An ear sensor provides physiological parameter monitoring. The ear sensor may comprise an in-ear portion configured to fit in an ear of a user. The in-ear portion may include at least one light emitter configured to emit light into an ear tissue site of the user and at least one light detector configured output a signal responsive to at least a portion of the emitted light after attenuation by ear tissue of the ear tissue site.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of U.S. patent application Ser. No. 13/975,008, filed Aug. 23, 2013, titled “Ear Sensor,” which is a continuation of U.S. patent application Ser. No. 12/658,872, filed Feb. 16, 2010, titled “Ear Sensor,” which claims priority benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/152,964, filed Feb. 16, 2009, titled “Ear Sensor,” each of which is hereby incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Pulse oximetry systems for measuring constituents of circulating blood have gained rapid acceptance in a wide variety of medical applications, including surgical wards, intensive care and neonatal units, general wards, home care, physical training, and virtually all types of monitoring scenarios. A pulse oximetry system generally includes an optical sensor applied to a patient, a monitor for processing sensor signals and displaying results and a patient cable electrically interconnecting the sensor and the monitor. A pulse oximetry sensor has light emitting diodes (LEDs), typically one emitting a red wavelength and one emitting an infrared (IR) wavelength, and a photodiode detector. The emitters and detector are typically attached to a finger, and the patient cable transmits drive signals to these emitters from the monitor. The emitters respond to the drive signals to transmit light into the fleshy fingertip tissue. The detector generates a signal responsive to the emitted light after attenuation by pulsatile blood flow within the fingertip. The patient cable transmits the detector signal to the monitor, which processes the signal to provide a numerical readout of physiological parameters such as oxygen saturation (SpO 2 ) and pulse rate. 
         [0003]    Pulse oximeters capable of reading through motion induced noise are disclosed in at least U.S. Pat. Nos. 6,770,028, 6,658,276, 6,650,917, 6,157,850, 6,002,952, 5,769,785, and 5,758,644; low noise pulse oximetry sensors are disclosed in at least U.S. Pat. Nos. 6,088,607 and 5,782,757; all of which are assigned to Masimo Corporation, Irvine, Calif. (“Masimo”) and are incorporated by reference herein. An ear sensor is disclosed in U.S. Pat. No. 7,341,559 titled Pulse Oximetry Ear Sensor, also assigned to Masimo and also incorporated by reference herein. 
         [0004]    Advanced physiological monitoring systems may incorporate pulse oximetry in addition to advanced features for the calculation and display of other blood parameters, such as carboxyhemoglobin (HbCO), methemoglobin (HbMet) and total hemoglobin (Hbt), as a few examples. Advanced physiological monitors and corresponding multiple wavelength optical sensors capable of measuring parameters in addition to SpO 2 , such as HbCO, HbMet and Hbt are described in at least U.S. patent application Ser. No. 12/056,179, filed Mar. 26, 2008, titled Multiple Wavelength Optical Sensor and U.S. patent application Ser No. 11/366,208, filed Mar. 1, 2006, titled Noninvasive Multi-Parameter Patient Monitor, both incorporated by reference herein. Further, noninvasive blood parameter monitors and corresponding multiple wavelength optical sensors, such as Rainbow™ adhesive and reusable sensors and RAD57™ and Radical-7™ monitors for measuring SpO 2 , pulse rate, perfusion index (PI), signal quality (SiQ), pulse variability index (PVI), HbCO and HbMet among other parameters are also available from Masimo. 
       SUMMARY OF THE INVENTION 
       [0005]      FIG. 1  illustrates various areas of the ear  100  that are amenable to blood parameter measurements, such as oxygen saturation (SpO 2 ). An ear site has the advantage of more quickly and more accurately reflecting oxygenation changes in the body&#39;s core as compared to peripheral site measurements, such as a fingertip. Conventional ear sensors utilize a sensor clip on the ear lobe  110 . However, significant variations in lobe size, shape and thickness and the general floppiness of the ear lobe render this site less suitable for central oxygen saturation measurements than the concha  120  and the ear canal  130 . Disclosed herein are various embodiments for obtaining noninvasive blood parameter measurements from concha  120  and ear canal  130  tissue sites. 
         [0006]    One aspect of an ear sensor optically measures physiological parameters related to blood constituents by transmitting multiple wavelengths of light into a concha site and receiving the light after attenuation by pulsatile blood flow within the concha site. The ear sensor comprises a sensor body, a sensor connector and a sensor cable interconnecting the sensor body and the sensor connector. The sensor body comprises a base, legs and an optical assembly. The legs extend from the base to detector and emitter housings. An optical assembly has an emitter and a detector. The emitter is disposed in the emitter housing and the detector is disposed in the detector housing. The legs have an unflexed position with the emitter housing proximate the detector housing and a flexed position with the emitter housing distal the detector housing. The legs are moved to the flexed position so as to position the detector housing and emitter housing over opposite sides of a concha site. The legs are released to the unflexed position so that the concha site is grasped between the detector housing and emitter housing. 
         [0007]    In various embodiments, the ear sensor has a resilient frame and a one piece molded skin disposed over the resilient frame. A cup is disposed proximate the detector housing and has a surface that generally conforms to the curvature of the concha site so as to couple the detector to the concha site and so as to block ambient light. A sensor cable has wires extending from one end of the sensor cable and disposed within channels defined by the resilient frame. The wires electrically and mechanically attach to the optical assembly. A connector is attached to the other end of the sensor cable, and the cable wires electrically and mechanically attach to the connector so as to provide communications between the connector and the optical assembly. 
         [0008]    In other embodiments, a stabilizer maintains the position of the detector housing and the emitter housing on the concha site. The stabilizer may have a ring that encircles the legs. The ring has a hold position disposed against the legs and a release position spaced from the legs. A release, when pressed, moves the ring from the hold position to the release position, allowing the ring to slidably move along the legs in a direction away from the base so as to increase the force of the emitter housing and detector housing on the concha site in the hold position and in a direction toward the base so as to decrease the force of the emitter housing and the detector housing on the concha site in the hold position. The stabilizer may have an ear hanger that rests along the back of the ear and couples to at least one of the legs and the sensor cable. 
         [0009]    Another aspect of an ear sensor comprises providing a sensor body having a base, legs extending from the base and an optical housing disposed at ends of the legs distal the base. An optical assembly is disposed in the housing. The sensor body is flexed so as to position the housing over a concha site. The sensor body is unflexed so as to attach the housing to the concha site and position the optical assembly to illuminate the concha site. 
         [0010]    In various embodiments, an ear surface conforming member is molded to at least a portion of the housing so as to physically couple the housing to the concha site and block ambient light from the optical assembly accordingly. The force of the housing against the concha site is adjusted. The adjusting comprises positioning a force adjustment ring on the sensor body so as to encircle the legs. The positioning comprises squeezing a ring release so as to move ring grips away from the legs, moving the force adjustment ring along the legs and toward the housing so as to increase the force of the housing on the concha site, and moving the force adjustment ring along the legs and away from the housing so as to decrease the force of the housing on the concha site. 
         [0011]    In other embodiments, an aspect of the ear sensor comprises supporting at least a portion of the weight of the sensor body and corresponding sensor cable so as to reduce the force needed to attach the housing to the concha site. The supporting comprises attaching at least one of the sensor body and sensor cable to an ear hook placed over the ear. 
         [0012]    A further aspect of an ear sensor comprising a clip means having a flexed position and an unflexed position. An optical means transmits multiple wavelength light into a tissue site when activated and receives the light after attenuation by pulsatile blood flow within the tissue site. The optical means is disposed on the clip means so that the optical means can be positioned on a concha site in the flexed position and pinched against the concha site in the unflexed position. A connector means mechanically attaches to and electrically communicates with a monitor. A cable means interconnects the connector means with the optical means. In various embodiments, the clip means comprises a resilient frame means for securing the optical means in a fixed position relative to the tissue site. A housing means encloses the resilient frame means and the optical means. A cup means physically couples at least a portion of the optical means to the concha site and blocks ambient light from the optical means. An adjustable force means holds the clip means to the concha site. Alternatively, or in addition to, a support means holds the clip means to the concha site. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is an illustration of the pinna or external ear structure, including the concha; 
           [0014]      FIGS. 2A-B  and  3 A-B illustrate various ear sensor embodiments; 
           [0015]      FIGS. 2A-B  are a side view and a perspective view of an ear bud embodiment of an ear sensor; 
           [0016]      FIGS. 3A-B  are perspective views of a flexible ear pad embodiment of an ear sensor; 
           [0017]      FIGS. 4A-D ,  5 A-B,  6 A-B, and  7 A-C illustrate various ear bud/pad attachment embodiments for a concha site; 
           [0018]      FIGS. 4A-D  are side views of “C”-clip embodiments for attaching an ear sensor to a concha site; 
           [0019]      FIGS. 5A-B  are perspective views of alligator clip embodiments for attaching an ear sensor to a concha site; 
           [0020]      FIGS. 6A-B  are perspective views of a clear adhesive disk embodiment for attaching an ear sensor to a concha site; 
           [0021]      FIGS. 7A-C  are perspective views of a flexible magnet disk embodiment for attaching an ear sensor to a concha site; 
           [0022]      FIGS. 8A-B ,  9 A-B, and  10 A-B illustrate various “hearing aid” style ear sensor embodiments that integrate the ear sensor with an attachment mechanism; 
           [0023]      FIGS. 8A-B  illustrate a concha-placed reflective sensor embodiment; 
           [0024]      FIGS. 9A-B  illustrate an “in-the-canal” reflective sensor embodiment; 
           [0025]      FIGS. 10A-B  illustrate “behind-the-ear” transmissive and/or reflective sensor embodiments; 
           [0026]      FIGS. 11A-B  and  12 A-F illustrate additional integrated ear sensor and attachment embodiments; 
           [0027]      FIGS. 11A-B  illustrate an integrated ear lobe attachment and concha-placed sensor embodiment; 
           [0028]      FIGS. 12A-F  illustrate a “Y”-clip sensor embodiment for concha-placement; 
           [0029]      FIGS. 13A-F ,  14 A-B,  15 A-B, and  16  illustrate various ear sensor attachment support embodiments; 
           [0030]      FIGS. 13A-F  are side views of ear-hook support embodiments; 
           [0031]      FIGS. 14A-B  are perspective views of headband support embodiments; 
           [0032]      FIGS. 15A-B  are front and perspective views of a “stethoscope” support embodiment; 
           [0033]      FIG. 16  is a perspective view of a “headphone” support embodiment; 
           [0034]      FIGS. 17A-B ,  18 A-E,  19 ,  20 A-B,  21 A-B,  22 A-B,  23 A-B,  24 A-C,  25 A-E,  26 A-F, and  27 A-F illustrate a concha-clip sensor embodiment having an orthogonally-routed sensor cable; 
           [0035]      FIGS. 17A-B  are perspective views of a concha-clip sensor; 
           [0036]      FIGS. 18A-E  are top, perspective, front, detector-side and emitter-side views, respectively, of a concha-clip sensor body; 
           [0037]      FIG. 19  is an exploded view of an concha-clip sensor; 
           [0038]      FIGS. 20A-B  are assembly and detailed assembly views of a concha-clip sensor; 
           [0039]      FIG. 21A-B  are a mechanical representation and a corresponding electrical (schematic) representation of a concha-clip sensor having a DB9 connector; 
           [0040]      FIG. 22A-B  are a mechanical representation and a corresponding electrical (schematic) representation of a concha-clip sensor having a MC8 connector; 
           [0041]      FIG. 23A-B  are a mechanical representation and a corresponding electrical (schematic) representation of a concha-clip sensor having a M15 connector; 
           [0042]      FIGS. 24A-C  are assembly step representations for installing an optical assembly into a resilient frame and installing the resilient frame into a sensor housing; 
           [0043]      FIGS. 25A-E  are top, perspective, front, side cross-section; and side views, respectively, of a force adjustment ring; 
           [0044]      FIGS. 26A-F  are top, disassembled perspective, assembled perspective, front, detector-side and emitter-side views of a concha-clip sensor body and corresponding force adjustment ring; and 
           [0045]      FIGS. 27A-F  are top, bottom, perspective, detector-side, front, emitter side and perspective views, respectively of an concha-clip sensor body having a parallel-routed sensor cable. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0046]      FIGS. 2A-B  illustrate an ear bud embodiment of an ear sensor  200  having an emitter ear bud  210 , a detector ear bud  220  and connecting cables  230 . The emitter ear bud  210  has a generally concave surface for attachment to the back of an ear. The detector ear bud  220  has a generally convex surface  222  for attachment inside the ear at a concha site opposite the emitter ear bud  210 . Sensor cables  230  are attached at the back of each ear bud having wires for electrical communications with a physiological monitor, such as a pulse oximeter. In particular, the emitter ear bud  210  includes wires for receiving emitter drive current from a monitor and the detector ear bud  220  includes wires for transmitting photodiode current to the monitor. 
         [0047]      FIGS. 3A-B  illustrate a flexible ear pad embodiment of an ear sensor  300  having an emitter pad  310 , a detector pad  320  and corresponding cables  330 . The sensor pads  310 ,  320  advantageously include a housing for each of the emitter pad  310  and the detector pad  320 , minimizing the number of unique parts for the ear sensor. The detector pad  320  houses a shielded detector assembly (not shown). The emitter pad houses  310  an emitter (not shown). Both the detector pad  320  and the emitter pad  310  are connected to a sensor cable  330 . The pads  310 ,  320  have an integrated bend relief  304  providing a finger grip. The pad face  306  provides a generally planar, pliant contact surface that can adapt to the curved front and back surfaces of a concha site. The pad face  306  has a relatively large area to minimize contact force. The housing  302  is injection molded of a pliant material. In one embodiment, the material is a medical grade thermoplastic elastomer. 
         [0048]      FIGS. 2A-B  and  3 A-B, above, illustrate various ear sensor embodiments. Although described with respect to ear bud and flexible ear pad enclosures, the sensor emitter and detector may be enclosed in any number of housings having various sizes and shapes of ear tissue contact surfaces, may use various types of electrical interconnnect and use various materials so as to noninvasively measure blood parameters from the concha area of the ear. As an example, the detector and emitter may both be mounted at one end of a “Y”-shaped flex circuit that has a connector at the opposite end. Although described above with respect to a detector placed inside the ear and an emitter placed outside the ear, a suitable alternative is the emitter inside and the detector outside the ear. Detector and emitter assemblies are described with respect to  FIGS. 19-20 , below. 
         [0049]      FIGS. 4A-D  illustrate “C”-clip embodiments  400  for attaching an ear sensor  410  to a concha site. The clip  400  is adapted for use with either the ear bud or the ear pad embodiments described above. The clip  400  has sensor mounts  420  fixedly attached to each end of a flexible “C”-shaped body  422 . The body  422  is made of a suitable material having an appropriate stiffness so as to provide a comfortable yet secure attachment to ear tissue. The sensor mounts  420  have mounting apertures sized for the ear buds or ear pads described above. The ear buds or pads are secured within the apertures with a friction fit or adhesive. In an alternative embodiment, the sensor housings are molded or otherwise integrated with the sensor mounts. 
         [0050]    As shown in  FIGS. 4A-B , in one embodiment  401  the unflexed clip  400  ( FIG. 4A ) is compressed between fingertips so that the clip ends  424  are crossed ( FIG. 4B ) and the contact surfaces of the ear sensor  412  are facing each other. The clip  400  is placed over the ear so that the detector and emitter ear buds are on opposite sides of the ear. Finger pressure on the clip  400  is then released so that the clip tension holds the sensor contact surfaces  412  against the concha tissue. As shown in  FIGS. 4C-D , in another embodiment  403  the clip ends  424  are crossed in both the flexed position ( FIG. 4C ) and the unflexed position ( FIG. 4D ). Otherwise, sensor attachment is as described above. Although described above as a “C”-shape, the clip body can be constructed of any of various springy, pre-formed materials having a variety of shapes and sizes so as to attach to ear tissue via compression and release between finger and thumb. 
         [0051]      FIGS. 5A-B  illustrate an alligator clip embodiment for attaching an ear sensor to a concha site. The alligator clip  500  has opposing heads  510 , each with a thru-hole  512  sized to accommodate either an ear pad sensor  300  ( FIG. 5A ) or an ear bud sensor  200  ( FIG. 5B ). The alligator clip  500  also has finger grips  520  each with a channel  530  for routing the sensor cabling  540 . The alligator clip is compressed and released to position and then attach the corresponding ear sensor to a concha site. 
         [0052]      FIGS. 6A-B  illustrate an adhesive disk embodiment for attaching an ear sensor to a concha site. Clear disks  600  have an adhesive on both surfaces. The adhesive is bio-compatible on at least the tissue-facing surface. The disks  600  are first attached to the sensor  200  or to a concha site  10 . Then the ear sensor  200  is attached on opposite sides of the concha tissue  10 . The disks  600  are sized to accommodate either an ear bud sensor  200 , as shown, or an ear pad sensor  300  ( FIGS. 3A-B ). 
         [0053]      FIGS. 7A-C  illustrate a flexible magnet disk embodiment for attaching an ear sensor to a concha site. Flexible magnetic disks  700 , such as made from a mixture of a ferrite powder and a rubber polymer resin, are permanently or temporarily attached to an ear sensor  200 . The attachment may be by friction fit or a removable or permanent adhesive. The ear sensor  200  is then placed on opposite sides of the concha site  10  and held in place by the magnetic force of the disks. One or both disks may be permanently magnetized during manufacture. The disks  700  are sized to accommodate either the ear bud sensor  200 , as shown, or the ear pad sensor  300  ( FIGS. 3A-B ). In an alternative embodiment, each of the ear sensor housings is at least partially composed of a high magnetic permeable material. One or both of the housings are magnetized. In another embodiment, one or more rare earth magnets are embedded in one or both housings. 
         [0054]      FIGS. 4A-D ,  5 A-B,  6 A-B, and  7 A-C, described above, illustrate various ear sensor attachment embodiments. Although described with respect to clips and adhesive or magnetic disks, the sensor emitter and detector may be attached to an ear tissue site using various other materials and mechanisms. For example, ear buds or pads may attach via suction cups or disks. Also, an emitter and detector may be integrated with disposable adhesive pads configured with snaps or other mechanical connectors for attaching and removing sensor leads from the disposable pads. In another embodiment, a sensor may be mounted in the concha or the ear canal using an expanding foam material that is first squeezed and then released after sensor placement within the ear. 
         [0055]      FIGS. 8A-B  illustrate a concha-placed reflective sensor embodiment. In one embodiment the sensor  800  has an ear canal extension  810  ( FIG. 8B ). In an embodiment, the ear canal extension has at least one emitter and at least one detector disposed proximate the extension surface so as to transmit light into ear canal tissue and to detect the transmitted light after attenuation by pulsatile blood flow within the ear canal tissue. In an embodiment, the emitter and detector are axially spaced on the extension. In an embodiment, the emitter and detector are radially spaced on the extension at a fixed angle, which may be, as examples, 30, 45, 90, 120, 135, 160 or 180 degrees. 
         [0056]    In an embodiment, the concha-placed sensor body  820  has at least one emitter and at least one detector in lieu of an ear canal extension emitter and detector. The sensor body emitter and detector are disposed proximate the concha surface so as to transmit light into concha tissue and to detect the transmitted light after attenuation by pulsatile blood flow within the concha tissue. In an embodiment, the concha-placed sensor body  820  and the ear canal extension  810  both have at least one emitter and at least one detector, creating a multi-site (concha and ear canal) reflective sensor. Connected with the sensor body  820  is a sensor cable  830  providing electrical communications between sensor body/ear canal emitter(s) and detector(s) and a monitor. Detector and emitter assemblies are described with respect to  FIGS. 19-20 , below. 
         [0057]      FIGS. 9A-B  illustrate an “in-the-canal” ear sensor embodiment. The ear canal sensor  900  has a base  910 , an ear canal extension  920  and a sensor cable  930 . Similar to the embodiment described above, the ear canal extension  920  has at least one emitter  922  and at least one detector  924  disposed proximate the extension surface so as to transmit light into ear canal tissue and to detect the transmitted light after attenuation by pulsatile blood flow within the ear canal tissue. The emitter  922  and detector  924  may be axially-spaced on the ear canal extension a fixed distance. Alternatively, the emitter and detector may be radially-spaced on the ear canal extension at any of various angles, such as 30, 45, 90, 120, 135, 160 or 180 degrees, to name a few. A sensor cable  930  is attached to the sensor so as to extend from the ear canal to a corresponding monitor. 
         [0058]      FIGS. 10A-B  illustrate “behind-the-ear” transmissive and/or reflective sensor embodiments. The ear sensor  1000  has a concha-placed body  1010 , an ear piece  1020 , a connecting piece  1030  attaching the concha body  1010  and the ear piece  1020  and a sensor cable  1040 . In one embodiment, a concha-placed body  1010  houses a detector and the ear piece  1020  houses an emitter opposite the detector so as to configure a transmissive concha sensor. In an embodiment, the concha-placed body  1010  or the ear piece  1020  has both an emitter and a detector so as to configure a reflective concha sensor. In an embodiment, the concha body  1010  and the ear piece  1020  are configured for multi-site transmissive and/or reflective concha tissue measurements. In an embodiment, the concha body  1010  also has an ear canal extension (see, e.g.  810   FIG. 8B ), which may also have an emitter and detector for multi-site concha and ear canal measurements. A sensor cable  1040  extends from the ear piece  1020  as shown. Alternatively, a sensor cable extends from the concha body, such as shown in  FIG. 8B , above. 
         [0059]      FIGS. 11A-B  illustrate a concha sensor  1100  having an alligator clip  1110 , a concha piece  1120 , a ear back piece  1130 , a lobe attachment  1140  and a sensor cable  1150 . In an embodiment, the alligator clip  1110  attaches to the ear lobe  20  so as to provide the physical support for a concha sensor  1100 . A convex body  1122  extends from the concha piece  1120 . A detector disposed at the convex body  1122  surface is disposed against the concha tissue  10 . A concave surface  1132  is defined on the back piece  1130  and positioned behind the ear. An emitter disposed at the concave surface  1132  is disposed against the ear wall opposite the concha detector. The concha piece  1120  and ear back piece  1130  are “springy” so as to securely contact the concha tissue  10  under the force of the alligator clip  1110 , but without undue discomfort. In an embodiment, the lobe attachment  1140  also has an emitter and detector so as to provide multi-site ear tissue measurements at the ear lobe  20  and the concha  10 . 
         [0060]      FIGS. 12A-F  illustrate a “Y”-clip ear sensor  1200  having a base  1210 , a pair of curved clips  1220  extending from the base, an emitter assembly  1230  extending from one clip end and a detector assembly  1240  extending from another clip end. The clips  1220  are tubular so as to accommodate wires from the emitter/detector assemblies, which extend from apertures  1212  in the base. Each assembly has a pad  1232 , a molded lens  1234  and a lid  1236 , which accommodate either an emitter subassembly or a detector subassembly. The Y-“clips” flex so as to slide over the ear periphery and onto either side of the concha. The integrated emitter and detector, so placed, can then transmit multiple wavelength light into the concha tissue and detect that light after attenuation by pulsatile blood flow within the concha tissue. 
         [0061]      FIGS. 13A-F  illustrate ear hook sensor support embodiments having an ear hook  1300  with cable  1310 , fixed  1320  or sliding  1330  support for either an alligator clip or a “Y”-clip sensor. These embodiments are also applicable to “C”-clip sensors and alligator clip sensors, among others. 
         [0062]      FIGS. 14A-B  illustrate headband sensor support embodiments. In one embodiment, the headband  1400  secures a concha body ( FIGS. 8A-B ) or an ear canal sensor ( FIGS. 9A-B ) by placement over the ear. In another embodiment, the headband  1400  provides a cable support for an ear clip sensor. 
         [0063]      FIGS. 15A-B  illustrate a “stethoscope”  1500  sensor support embodiment. In this embodiment, one ear piece  1510  is integrated with an ear canal sensor  1520 , such as described above with respect to  FIGS. 9A-B . In another embodiment, both stethoscope ear pieces  1510  are integrated with ear canal sensors for multi-site (both ears) blood parameter measurements. 
         [0064]      FIG. 16  illustrates a “headphone”  1600  support embodiment. In one embodiment (not shown), a headphone ear piece secures a concha body ( FIGS. 8A-B ) or an ear canal sensor ( FIGS. 9A-B ) by placement over the ear, in a similar manner as described with respect to  FIGS. 14A-B . In another embodiment, the headphone  1600  provides a “ring-shaped” earpiece  1610  that provides a cable support  1612  for an ear clip sensor  1200 , as shown. 
         [0065]      FIGS. 17A-B  illustrate a concha-clip ear sensor  1700  embodiment having a sensor body  1800 , a connector  1710  and a sensor cable  1720  providing communications between the sensor body  1800  and the connector  1710 . As described in further detail with respect to  FIGS. 18A-E , the sensor body  1800  has resilient legs that are manually flexed so as to slide over an ear periphery and onto either side of a concha site. As described in further detail with respect to  FIG. 19 , the sensor body  1800  incorporates an optical assembly  1910  ( FIG. 19 ) configured to transmit multiple wavelength light into the concha tissue and detect that light after attenuation by pulsatile blood flow within the concha tissue. In a particular embodiment, the sensor body  1800  has an emitter housing  1840  ( FIGS. 18A-E ) configured to fit inside the ear and a detector housing  1850  ( FIGS. 18A-E ) configured to fit outside the ear. In other embodiments, the sensor body is configured so as to place an emitter outside the ear and a detector inside the ear. In an embodiment, the sensor body  1800  is configured so that the sensor cable  1720  extends generally perpendicular to the sensor body  1800 , as shown and described with respect to  FIGS. 17-26 . In another sensor body embodiment  2700  ( FIGS. 27A-F ) the sensor cable  1720  extends generally parallel to the sensor body, as described in further detail with respect to  FIGS. 27A-E , below. Although the sensor body  1800 ,  2700  as described below has legs  1830  extending from a base  1810  so as to generally form a “U”-shape, the sensor body  1800 ,  2700  can be constructed of any of various resilient, pre-formed materials having a variety of shapes and sizes so as to attach to ear tissue, such as a concha site or ear lobe site. 
         [0066]      FIGS. 18A-E  further illustrate a sensor body  1800  having a base  1810 , a strain relief  1820  formed at a side of the base  1810  and a pair of resilient legs  1830  extending from the base  1810 . The strain relief  1820  has a cable aperture  1822  that accommodates the sensor cable  1720  ( FIGS. 17A-B ). An emitter housing  1840  extends from one leg  1830  and a detector housing  1850  extends from the other leg  1830 . The legs  1830  accommodate cable conductors extending between the connector  1710  ( FIGS. 17A-B ) and an optical assembly  1910  ( FIG. 19 ) located in the housings  1840 ,  1850 . Each housing  1840 ,  1850  has an optical end  1842 ,  1852  ( FIG. 20B ) having an aperture  1844 ,  1854  ( FIG. 20B ) that passes light from the emitter housing  1840  to the detector housing  1850 . In an embodiment, the housings  1840 ,  1850  fit on either side of a concha tissue site so that light is transmitted from an emitter  1916  ( FIG. 19 ), through the concha tissue and received by a detector  1912  ( FIG. 19 ), as described in detail below. In an embodiment, the emitter housing  1840  fits within the ear and the detector housing  1850  outside the ear. In an embodiment, a cup  1860  extends from the detector housing  1850 . The cup  1860  has a generally circular edge and a curvature that accommodates the surface behind the ear. Accordingly, the cup  1860  advantageously provides a more comfortable and secure fit of the detector housing  1850  to the ear and further functions as a light shield, blocking external light sources from the detector  1912 . The resilent legs  1830  are manually flexed so that the emitter housing  1840  is moved away from the detector housing  1850  so as to position the detector housing  1850  and emitter housing  1840  over opposite sides of a concha site. The legs are then released to an unflexed position so that the concha site is grasped between the detector housing  1850  and emitter housing  1840 . 
         [0067]      FIGS. 19 ,  20 A-B further illustrates a concha-clip ear sensor  1700  having a connector  1710  in communications with a sensor body  1800  via a sensor cable  1720 . The sensor body  1800  has an optical assembly  1910 , a resilient frame  1920 , a sensor housing  1930  and lenses  1940 . As shown in  FIGS. 19-20 , the optical assembly  1910  has a detector  1912 , a detector shield  1914 , a light barrier  1915 , an emitter  1916  and white electrical tape  1918 . The cable  1720  has emitter wires  1722  and detector wires  1724  that are soldered to the emitter  1916  and detector  1912 , respectively, and communicate emitter drive signals and detector response signals to/from the connector  1710 . 
         [0068]    Also shown in  FIGS. 19 ,  20 A-B, the resilient frame  1920  has an emitter channel  1926  terminating at an emitter holder  1924 , a detector channel  1927  terminating at a detector holder  1925 , a strain relief  1928  and a frame hole  1929 . The optical assembly  1910  fits within the resilient frame  1920 . In particular, the emitter wires  1722  are disposed within the emitter channel  1926 , the detector wires  1724  are disposed in the detector channel  1927 , the emitter is disposed in the emitter holder  1924  and the detector  1912  and corresponding shield  1914  and light barrier  1915  are disposed in the detector holder  1925 . In an embodiment, the sensor housing  1930  is a one piece silicon skin disposed over the resilient frame  1920  and the optical assembly  1910 , as described with respect to  FIGS. 24A-C , below. In an embodiment, the resilient frame  1920  is a polypropylene/ santoprene blend. The lenses  1940  are disposed within housing apertures  1844 ,  1854 . In an embodiment, the lenses  1940  are formed from a translucent silicone adhesive. In an alternative embodiment, the lenses  1940  are separately formed from clear silicone and glued into place with a translucent silicone adhesive. 
         [0069]      FIGS. 21A-B ,  22 A-B,  23 A-B further illustrate concha-clip sensor embodiments  2100 ,  2200 ,  2300  having a DB9 connector  2130  ( FIGS. 21A-B ), a MC8 connector  2230  ( FIGS. 22A-B ) or a M15 connector  2330  ( FIGS. 23A-B ). The sensor bodies  2110 ,  2220 ,  2330  have red and IR emitters  2112 ,  2212 ,  2312  and detectors  2114 ,  2214 ,  2314  in communication with connectors  2130 ,  2230 ,  2330  via emitter wires  2152 ,  2252 ,  2352  and detector wires  2154 ,  2254 ,  2354 . Sensor ID resistors  2132 ,  2232 ,  2332  are mounted in parallel with the emitters, and can be read by a monitor generating currents below the emitter-on thresholds. Compatibility resistors  2134 ,  2334  can be read by other monitor types. EEPROMs  2136 ,  2236 ,  2336  programmed with various sensor information can be read by more advanced monitors. Shield wires  2156 ,  2256 ,  2356  provide conductive paths via the connectors to a common shield ground. In an embodiment, ID resistors are 12.7 KΩ, compatibility resistors are 6.81 KΩ, and EEPROMs are 1-wire, 20 Kbit memories available from Maxim Integrated Products, Inc., Sunnyvale, Calif. 
         [0070]      FIGS. 24A-C  illustrate integration of the optical assembly  1910  disposed at the end of a sensor cable  1720 , the resilient frame  1920  and the sensor housing  1930 . As shown in  FIG. 24A , the optical assembly  1910  is threaded into the sensor housing  1930 . In particular, in a couple steps  2401 - 2402 , the optical assembly  1910  is inserted into the sensor housing  1930  through the cable aperture  1822 . In a further couple steps  2403 - 2404 , the optical assembly  1910  and portions of the attached sensor cable  1720  are pulled through the cable aperture  1822  and out of a U-slot  1932  of the sensor housing  1930 . 
         [0071]    As shown in  FIG. 24B , in a step  2405 , the optical assembly  1910  is integrated with the resilient frame  1920  to form a frame assembly  2490 . In particular, the detector assembly  1919  is inserted into a detector holder  1925  to form a framed detector  2495 . Also, the emitter  1916  is inserted into an emitter holder  1924  to form a framed emitter  2495 . 
         [0072]    As shown in  FIG. 24C , the frame assembly  2490  is integrated with the sensor housing  1930  to form the sensor body  1800 . In several steps  2406 - 2408  the framed emitter  2494  is inserted into a pocket within the emitter housing  1840 . In a couple additional steps  2409 - 2410 , the framed detector  2495  is inserted into a pocket within the detector housing  1850 . In a step  2411 , a housing post  1934  is inserted into the frame hole  1929 . In several additional steps  2412 - 2414 , excess cable  1720  is removed from the sensor housing  1930  via the cable aperture  1822 , and the U-slot  1932  is closed and sealed with an adhesive. The resulting sensor body  1800  is described in detail with respect to  FIGS. 18A-E , above. 
         [0073]      FIGS. 25A-E ,  26 A-F illustrate a force adjustment ring  2500  that slidably attaches to the sensor body  1800  so as to adjust the force of the sensor housings  1840 ,  1850  against concha tissue. The ring  2500  forms a generally oval opening  2526  having a pair of opposing sensor grips  2520  generally centered along a long axis of the opening  2526  and a pair of finger releases  2510  generally centered along a short axis of the opening  2526 . The sensor grips  2520  have toothed faces  2525  configured to contact the sensor body legs  1830 . The finger releases  2510  allow the ring to be squeezed between a finger and thumb, say, so as to compress the ring short axis, thereby lengthening the ring long axis and releasing the toothed faces  2525  from the legs  1830 . In this manner, the ring  2500  can be positioned closer to or farther from the housings  1840 ,  1850  so as to increase or decrease the force on a concha tissue site. 
         [0074]      FIGS. 27A-F  illustrate an sensor body  2700  configured for a parallel-routed sensor cable, as compared with the sensor body  1800  ( FIGS. 18A-E ) configured for a perpendicular-routed sensor cable, as described above. The sensor body  2700  has a base  2710 , a strain relief  2720  formed at a bottom end of the base  2710  and a pair of resilient legs  2730  extending from an opposite end of the base  2710 . The strain relief  2720  has an aperture  2722  that accommodates the sensor cable  1720  ( FIGS. 17A-B ). An emitter housing  2740  extends from one leg  2730  and a detector housing  2750  extends from the other leg  2530 . The legs  2730  accommodate cable conductors extending between a connector  1710  ( FIGS. 17A-B ) and an optical assembly  1910  ( FIG. 19 ) located in the housings  2740 ,  2750 . Each housing  2740 ,  2750  has an optical end having an aperture that passes light from the emitter housing  2740  to the detector housing  2750 . In an embodiment, the housings  2740 ,  2750  fit on either side of a concha tissue site so that light is transmitted from an emitter of the optical assembly, through the concha tissue and received by a detector of the optical assembly. In an embodiment, the emitter housing  2740  fits within the ear and the detector housing outside the ear. In an embodiment, a cup  2760  extends from the optical end of the detector housing  2750 . The cup  2760  has a generally circular edge and a curvature that accommodates the outside curvature of the ear. Accordingly, the cup  2760  advantageously provides a more comfortable and secure fit of the detector housing  2750  to the ear and further functions as a light shield, blocking external light sources from the detector assembly. 
         [0075]    A sensor body  1800  ( FIGS. 18A-E ),  2700  ( FIGS. 27A-F ) is described above with respect to directly flexing resilient legs in order to space apart emitter and detector housings for placement on a concha site. In another embodiment, a pair of finger levers can extend from the legs to a position below the sensor body base opposite the resilient legs. The finger levers can be squeezed between finger and thumb so as to flex the resilient legs for concha site placement. 
         [0076]    In a particular advantageous embodiment, a single finger lever can extend from one leg to a position below the base. This single finger lever can be squeezed using a sensor cable portion extending from the sensor body base for leverage. Such a single finger lever configuration eliminates potential discomfort from a second lever poking a patient&#39;s neck area. 
         [0077]    An ear sensor has been disclosed in detail in connection with various embodiments. These embodiments are disclosed by way of examples only and are not to be construed as limiting the scope of the claims that follow. One of ordinary skill in art will appreciate many variations and modifications.