Abstract:
The present invention is directed to a holder for use in positioning a pulse oximeter sensor in multiple selectable locations relative to a patient&#39;s extremities. The holder includes at least one flexible elongate member that is conformable to and, preferably, about a patient&#39;s extremity. A connector on the elongate member is utilized to secure the elongate member to the patient&#39;s extremity. Additionally, the elongate member&#39;s inside surface contains one or more recesses for selectively receiving a sensor and holding that sensor relative to one or more positions on the inside surface of the flexible sensor holder. The inclusion of multiple recesses allows medical personnel flexibility in positioning a medical sensor. In one embodiment, the holder includes two elongate members for conforming about two portions of a patient&#39;s extremity to reduce movement between the extremity and a sensor held by the sensor holder.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. 119(e)(1) to U.S. Provisional Application No. 60/366,330 entitled: “Neonatal Bootie Wrap,” filed on Mar. 21, 2002; the contents of which are incorporated herein as if set forth in full. 
    
    
     FIELD OF THE INVENTION 
     The present invention is generally directed to a holder for positioning medical sensors relative to a patient&#39;s tissue. More specifically, the present invention is directed to a holder for use in positioning a pulse oximeter sensor in multiple selectable locations relative to a patient&#39;s extremities. 
     BACKGROUND OF THE INVENTION 
     In many medical applications it is desirable to hold one or more sensors in contact with a patient&#39;s tissue such that various non-invasive measurements of physiological events may be made. For example, pulse oximeter sensors may be held in contact with a patient&#39;s tissue to non-invasively determine pulse rate and/or blood oxygenation levels. When using a pulse oximetry sensor, it is important to properly position the sensor relative to the patient&#39;s tissue to ensure its proper operation. If the sensor is held too loosely relative to the tissue, it may not function; in contrast, if the sensor is pressed into the tissue, it may interfere with the physiological properties it is supposed to monitor. 
     Pulse oximeter sensors generally comprise a detector and at least one light source, which may be focused on or through a patient&#39;s tissue. Reflective type pulse oximeter sensors generally focus the light source(s) on the patient&#39;s tissue and the detector ‘receives’ light reflected back. Accordingly, reflective type sensors&#39; light source(s) and detector(s) may be contained in a single discrete unit and be held in contact with the same surface on a patient&#39;s tissue. Transmittance type pulse oximeter sensors, which transmit light through tissue a patient&#39;s tissue, require that the light source(s) and detector(s) be held to a patient&#39;s tissue such that an optical path through the tissue exists between the light source(s) and the detector(s) (e.g., through a finger, ear lobe, hand, foot etc.). Therefore, transmittance type sensors generally have light source(s) and detector(s) that are somewhat separated. Irrespective of the type of pulse oximetry sensor utilized, it is important that a holder provide flexibility in positioning the sensor in order to provide good conformance between the light source(s), detector(s), and the patient&#39;s tissue. 
     There are a number of additional considerations for sensor holders. First, the sensors used with such holders should have the ability to achieve a reliable interface between the sensor and the patient&#39;s tissue. Inherent in this first design consideration is the need to securely hold a sensor in place relative to the patient&#39;s tissue so the holder and sensor are resistant to unintended removal and/or slippage relative to the tissue. This is especially important for patients that are unable to control their movements or are likely to interfere with the sensor, such as infants. Second, the holder and sensor should be adapted for ready application and removal from the patient with minimal patient discomfort and ease of use for the applicator. Finally, the holder and sensor should provide a gentle interface with the patient&#39;s skin. 
     SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide a flexible sensor holder that provides a gentle interface for holding a sensor relative to multiple regions on one or more patient extremities. 
     Another object of the present invention is to provide a flexible sensor holder that provides improved sensor to tissue interface through the reduction of motion artifact. 
     Another object of the present invention is to provide a flexible sensor holder that is resistant to accidental removal and/or slippage relative to a patient extremity. 
     A further objective of the present invention is to achieve one or more of the above objectives where the flexible sensor holder comprises a low part count assembly that is simple to manufacture and cost efficient. 
     These and other objectives are addressed by the flexible sensor holder of the present invention that is used to hold a medical sensor relative to patient tissue. In a principal application the sensor holder is utilized to hold pulse oximetry sensors, therefore, the term “sensor” hereafter is meant to include both reflective and transmittance type pulse oximetry sensors unless otherwise stated. The flexible sensor holder is conformable to a patient&#39;s extremity and contains at least one connector to connect the flexible sensor holder to that extremity. Preferably, the connector is operative to selectively connect a first portion of the flexible sensor holder to a selectable second portion of the flexible sensor holder, thereby allowing the flexible sensor holder to accommodate extremities of varying sizes. A surface of the flexible sensor holder, which interfaces with a patient&#39;s tissue upon application to an extremity, includes one or more recesses for selectively receiving a medical sensor. Upon application of the sensor holder to a patient extremity, a sensor disposed within one such recess may be securely held in contact with the patient&#39;s tissue without pressing the sensor into the patient&#39;s tissue, which may result in, for example, blood vessel constriction (i.e., pressure necrosis). 
     According to a first aspect of the invention, a flexible sensor holder is provided having a plurality of sensor recesses to allow for added flexibility in positioning a medical sensor relative to a patient extremity. The flexible sensor holder includes a flexible elongate member that is conformable to and, preferably, about a patient&#39;s extremity. A connector on the elongate member is utilized to secure the elongate member to the patient&#39;s extremity. Additionally, an inside surface of the elongate member contains first and second spaced recesses for selectively receiving a sensor and holding that sensor relative to first and second positions on the inside surface of the flexible sensor holder. The inclusion of the first and second recesses allows medical personnel flexibility in positioning a medical sensor by providing two alternate positions along the elongate member to hold a sensor. Accordingly, upon application of the flexible sensor holder to a patient&#39;s extremity, a sensor may be held in first and second alternate positions relative to the patient&#39;s tissue. 
     In one recess spacing embodiment, the first and second recesses are entirely separated and, thereby, capable of holding a sensor to separate positions on the inside surface of the elongate member. These separate recesses may each further comprise discrete portions. For example, each recess may comprise a first portion for receiving a first portion of a sensor and a second portion for receiving a second portion of that sensor. In this regard, a first portion of each recess may be oriented along a portion of the elongate member&#39;s length while a second portion of each recess is oriented across the elongate member&#39;s width. These first and second recess portions may be connected forming, for example, L-shaped or T-shaped recess configurations. If the discrete portions of each recess are not connected, apertures through the elongate member may be utilized to “weave” a sensor through the elongate member thereby allowing a portion of that sensor to be seated in each recess portion, as will be more fully discussed herein. 
     Regardless if individual portions of each recess are connected, at least one portion of each recess will preferably extend to a lateral edge of the elongate member to provide access beneath the elongate member when the flexible sensor holder is connected about a patient&#39;s extremity. As will be appreciated, this allows for wiring attached to a sensor (e.g., a sensor cable) to pass beneath the flexible sensor holder without applying pressure to the patient&#39;s tissue. Further, each recess may extend to different lateral edges of the elongate member, allowing a sensor cable to be routed forward or rearward relative to the elongate member, depending on the recess utilized to receive the sensor. As will be appreciated, in some instances (e.g., patient&#39;s with sensitive skin) it may be desirable to route the sensor cable away from the patient to prevent skin irritation and/or to prevent a patient from pulling on the sensor cable. 
     The recesses may be sized and shaped to receive correspondingly configured sensors (e.g., L-shaped recesses for receiving L-shaped sensors). In this regard, each sensor recess may generally correspond to the shape of a sensor intended for use with the sensor holder. In one embodiment, the first and second sensor recesses are commonly shaped for holding a commonly shaped sensor at alternate locations along the elongate member. However, it will be appreciated that the recesses need not be commonly shaped nor correspondingly-shaped to a medical sensor. For example, the recesses may be differently shaped for receiving different sensors. Furthermore, where differently shaped recess are utilized, one recess may define a shape encompasses the shape defined by the other recess. In this regard, the former recess may be configured to hold the sensors that are utilized with the latter recess while also being configured to receive and hold alternatively shaped medical sensors. In any case, the recesses will preferably have a depth that allows a sensor received therein to be substantially planar with the surface of the elongate member (e.g., the recess depth and sensor thickness are substantially equal). In this regard, upon application to a patient&#39;s extremity, pressure applied by the sensor to the patient&#39;s tissue may be reduced or eliminated. 
     Generally, a connector is used to connect the elongate sensor holder around a patient&#39;s extremity by connecting a first portion of the elongate member to a second portion of the elongate member. Preferably, the connector is adjustable to allow selective connection of the first portion and second portions such that the length of the elongate member may be adjusted to accommodate extremities of varying sizes. Tapes, snaps and other connectors may be utilized, however, a particularly apt connector comprises of a plurality of loops or hooks attached to a portion of the elongate member&#39;s inside surface and a plurality of matching hooks or loops attached to a portion of the elongate member&#39;s outside surface. For example, the portion of the elongate member containing hooks/loops on its outside surface may have its inside surface conformed to the patient&#39;s tissue, thereby exposing the hooks/loops on its outside surface. The elongate member may then be “wound” around the patient&#39;s extremity allowing the matching hooks/loops on the inside surface of the elongate member to connect with the exposed hooks/loops. As will be appreciated, in this embodiment, a first portion of the elongate member will overlap a second portion of the elongate member creating a “flap.” In some instances, it may be preferable to orient this flap on the patient to minimize rubbing and/or the patient&#39;s ability to disconnect the connector through movement. For example, it may be preferable to orient the flap on the inside of the patient&#39;s hand with the flap directed toward the outside edge of the hand. 
     The use of a sensor holder with multiple recesses extending to opposing sides of the elongate member allows for both selective routing of a sensor cable (i.e., forward or backward) and selective orientation of the flap on the patient&#39;s extremity to minimize patient interference and/or discomfort. That is, by utilizing an elongate sensor holder having first and second recesses extending to opposing edges of the elongate member, enhanced patient comfort may be realized. Further, use of multiple recesses may allow for improved sensor placement that may result in improved optical paths through a patient&#39;s tissue (e.g., thinner tissue portions) as well as the ability to apply a sensor holder to an extremity without regard to right left extremity orientation. 
     The recesses may also contain retention means for selectively attaching a sensor to the flexible sensor holder. In this regard, the bottoms of the recesses may be coated with an adhesive and/or a peel-away release liner for selectively adhering a sensor within one of the recesses. That is, the peel-away release liner may be removed to expose an adhesive layer in one of the recesses that is utilized to adhere a sensor therein. Alternatively, a lip may be formed around an inside edge of each sensor recess allowing a sensor having a width greater than a corresponding width of the recess to be seated beneath the lip. This enables a portion of a sensor to be trapped beneath the lip while another part of the sensor has access to the patient&#39;s tissue. 
     In one embodiment the retention means comprises one or more apertures or “slits” passing through the flexible sensor holder. These slits allow a sensor to be weaved through the sensor holder. Preferably, these slits will pass through the sensor holder to allow access to one or more of the recesses. Utilizing one of these slits, a first portion of a sensor may be seated within a recess while a second portion of the sensor extends through the backside of the flexible sensor holder. More preferably, two slits are utilized, allowing the sensor to be threaded through the two slits wherein first and second portions of the sensor are seated in first and second recess portions. As will be appreciated, in this configuration the sensor is weaved through the flexible sensor holder similar to a needle threaded through fabric. 
     In a second aspect of the present invention, a method for positioning a sensor relative to a patient&#39;s tissue is provided. The method includes the steps of positioning a flexible sensor holder relative to a patient&#39;s tissue to, for example, determine the best orientation and/or tissue region for sensor placement. One of two provided sensor-holding recesses associated with a patient interface surface of the flexible holder is selected to hold a sensor. This may further include determining which recess will locate the sensor to a preferred location on the sensor holder and/or hold the sensor relative to a preferred tissue region on the patient. A sensor is located within the selected sensor holding recess. This may further entail, inter alia, orienting a sensor cable though a sensor cable slot interconnecting the selected recess to a lateral edge of the sensor holder and/or adhering the sensor to the selected recess. Once the sensor is properly located on the sensor holder (i.e., within the selected recess), a first portion of the sensor holder is connected to a second portion of the sensor holder to fasten the sensor holder about a patient&#39;s extremity. As will be appreciated, once attached to the patient&#39;s extremity, the sensor is held relative to the patient&#39;s tissue allowing the sensor to monitor one or more physiological events. 
     In a third aspect of the present invention, a flexible sensor holder operative to connect about two portions of a patient&#39;s extremity is provided. By providing a dual connection to the patient&#39;s extremity, the holder provides for further reduced movement between the sensor and the patient&#39;s tissue (e.g., reduced motion artifact). The dual connection flexible sensor holder comprises first and second elongate members that are connected by an interconnecting member. Each of these first and second elongate members is conformable to, and connectable about a patient&#39;s extremity. Accordingly, each elongate member contains a connector for selectively connecting that elongate member about the patient&#39;s extremity. Finally, the inside surface of at least one of the first and second elongate members contains one or more recesses for selectively receiving a sensor. Preferably, this elongate member will contain at least two recesses to provide medical technicians added flexibility in positioning a sensor relative the sensor holder in accordance with the present invention. 
     The first and second elongate members are spaced relative to one another so that they may be connected about first and second portions of a patient&#39;s extremity. Further, the interconnecting member may also be flexible to allow the first and second elongate members to move relative to one another and, thus, connect about first and second portions of an extremity in transverse planes. For example, the sensor holder may be manipulated such that the first elongate member is connectable around a patient&#39;s forefoot and the second elongate member is connectable around the patient&#39;s ankle. As will be appreciated, by connecting the flexible holder about two portions of a patient&#39;s extremity, the flexible sensor holder is more resistant to accidental slippage and/or removal. Additionally, by connecting about two portions of an extremity in transverse planes, motion between a sensor and a patient&#39;s tissue may be reduced. 
     As noted, at least one of the first and second elongate members contains a first and preferably a second sensor holding recess. Accordingly, if two recesses are utilized, the two recesses may be spaced to allow positioning a sensor in first and second alternate positions relative to the elongate member and/or to first and second alternate tissue regions upon application of the holder to a patient&#39;s extremity. For example, upon application of the flexible sensor holder a patient&#39;s foot and ankle, a first sensor recess may be available to hold a sensor to the inside edge of the patient&#39;s foot and a second sensor recess may be available to hold a sensor to the outside edge of the patient&#39;s foot. As will be appreciated, when using a transmittance type pulse oximetry sensor it is generally desirable to have an optical path through a thinner portion of a patient&#39;s tissue (e.g., an outside edge of a patient&#39;s foot); therefore, flexibility in placing a sensor on the sensor holder may provide an improved optical path and, therefore, improved sensor performance. Further, by providing flexibility in placing the sensor on the sensor holder, the sensor holder may be applied to right or left extremities. 
     In accordance with a fourth aspect of the present invention, a method of providing dual point connection for positioning a sensor relative to a patient&#39;s tissue is provided. In this regard, a flexible sensor holder operative to be connected about two portions of a patient&#39;s extremity is provided. The flexible sensor holder is positioned relative to the patient&#39;s extremity where sensor placement is desired. A sensor is located on the patient interface surface of the flexible sensor holder (e.g., received/adhered in a selected sensor holding recess). Once the sensor is located and the flexible holder is properly positioned, a first portion of the flexible holder is connected about a first portion of a patient&#39;s extremity and then a second portion of the flexible holder is connected about a second portion of the patient&#39;s extremity. As will be appreciated, the first and second connecting steps secure the sensor holder to the patient&#39;s extremity, which in turn holds the sensor relative to a patient&#39;s tissue. The first and second connecting steps may be performed on any appropriate patient extremity, however in a preferred application they are connected about transverse planes of a patient&#39;s extremity, such as a foot and ankle, to provide increased isolation between the patient&#39;s tissue and the sensor. 
     In a fifth aspect of the present invention, a flexible sensor holder is provided that is convertible from a dual connection flexible sensor holder to a single connection flexible sensor holder. In this regard, the flexible sensor holder comprises first and second elongate members that are each conformable to, and connectable about a patient&#39;s extremity. An interconnecting member connects the first elongate member to the second elongate member. One or both of the interfaces between the interconnecting member and the first and second elongate members is selectively detachable. That is, one or both of the elongate members are releaseably attached to the interconnecting member. 
     The releasable attachment of the interconnecting member allows one or both of the elongate members to be disconnected from the interconnecting member, thus, converting the dual connection sensor holder into a single connection sensor holder. The interconnecting member may be releaseably attached to either or both the first or second elongate members in any manner that is readily detachable by a medical technician. Preferably, at least one of the interfaces between the interconnecting member and the elongate members will be perforated to allow one or both of the elongate members to be disconnected by hand. 
     The disconnected elongate member may include a connector for connecting about a patient&#39;s extremity and may contain one or more recesses for holding a sensor relative to a patient&#39;s tissue. As will be appreciated, this allows the disconnected elongate member to be used as a single connection sensor holder for holding a sensor relative to a patient&#39;s tissue. As will be further appreciated, the present aspect of the invention allows a medical facility to stock a single flexible sensor holder that may be used in a variety of contexts. That is, the present aspect allows a technician to convert a dual connection sensor holder into a single connection sensor holder when needed, thus, providing additional flexibility in sensor application. 
     In a further aspect of the present invention, a flexible sensor holder comprising releaseably laminated layers is provided. As presented, the flexible sensor holder generally comprises a compressible material layer, in which one or more recesses may be formed, a backing layer releaseably laminated to the compressible material layer to impart structural qualities, and a connector to hold at least a first portion of the flexible sensor holder to a second portion of the flexible holder once wrapped about a patient&#39;s extremity. 
     The compressible material layer may be formed from foam, neoprene, rubber, fabric, composites thereof and other suitable materials that permit desired compression. Additionally, the compressible material will typically be of a thickness that allows one or more recesses of a predetermined depth to be formed therein. To facilitate manufacture, a preferred embodiment utilizes a compressible material having the same thickness as the desired recess depth. In this regard, the recesses may be formed by “punching” holes entirely through the compressible material layer and then laminating this layer to a backing layer. 
     The backing layer may be any flexible material and will preferably have a increased tensile strength in relation to the compressible material layer. In addition, for pulse oximetry applications it is preferable that the backing material provide light blocking characteristics to reduce noise effects of ambient light. In any case, the backing layer is releaseably laminated to the compressible material layer. In a preferred embodiment, the backing layer comprises a hook and loop material. This hook and loop material may have a plurality of hooks on a first side and a plurality of loops on a second side. Accordingly, the compressible material layer may contain two or more layers, e.g., a compressible material for interfacing with a patient&#39;s tissue and a hook or loop attachment layer interconnected to one side of the compressible material. This attachment layer may be releaseably laminated with the hook/loop backing material. Alternatively, a surface of the backing layer (e.g., a plurality of hooks) may be laminated directly to the compressible material layer (e.g., an open cell foam). 
     By extending the releaseably laminated backing layer beyond at least one end of the compressible material layer(s), one side of the backing material (e.g., hooks) may connect to the other side (e.g., loops) when the flexible sensor assembly is wrapped around an extremity, providing sensor holder that does not require a separately formed connector. The use of a compressible material and backing layer releaseably laminated together provides another benefit, namely, individual adjustment of the flexible sensor holder. For example, if an elongate flexible sensor holder was too long, the backing layer and compressible material may be separated, cut to a desired length, re-laminated, and applied to a patient&#39;s extremity. Unlike other configurations, this embodiment allows altering the sensor holders length without affecting the holder&#39;s connector mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a two elongate member flexible sensor holder for use with an L-shaped pulse oximetry sensor; 
         FIG. 2  shows a perspective view of a single elongate member flexible sensor holder for use with an L-shaped pulse oximetry sensor; 
         FIGS. 3   a  and  3   b  show front and rear perspective views of the flexible sensor holder of  FIG. 1  applied to a patient&#39;s foot and ankle; 
         FIG. 4  shows a perspective view the two elongate member flexible sensor holder of  FIG. 1  being converted to the single elongate member flexible sensor holder of  FIG. 2 ; 
         FIG. 5  shows the flexible sensor holder  FIGS. 2 and 4  applied to a patient&#39;s hand; 
         FIG. 6  shows a perspective view of a two elongate member flexible sensor holder for use with a T-shaped pulse oximetry sensor; 
         FIGS. 7   a ,  7   b  and  7   c  show alternate retention means for holding a sensor within a recess; 
         FIG. 8  shows an alternate embodiment of a two elongate member flexible sensor holder that utilizes releaseably laminated layers and sensor retention slits as shown in  FIGS. 7   b  and  7   c ; and 
         FIG. 9  shows an exploded cross sectional view of a portion of the sensor holder of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described in relation to the accompanying drawings, which at least assist in illustrating its various pertinent features. The present invention, a flexible sensor holder, is described in all embodiments in conjunction with a transmittance type pulse oximetry sensor; however, it is to be expressly understood that the flexible sensor holder of the present invention may be utilized with reflective type pulse oximetry sensors as well as other non-invasive medical sensors. 
       FIG. 1  shows a first embodiment a dual connection flexible sensor holder  20 . The dual connection flexible holder  20  includes a first elongate member  30  for conformably wrapping around a first portion of a patient&#39;s extremity, a second elongate member  50  for conformably wrapping around a second portion of a patient&#39;s extremity and an interconnecting member  44  interconnecting the first and second elongate members  30 ,  50 . The interconnecting member  44  attaches the two substantially parallel elongate members  30 ,  50  such that the flexible sensor holder  20  generally comprises an H-shape prior to application to a patient&#39;s extremity. 
     The flexible sensor holder  20  further contains a compressible material layer  24  and a backing layer  28 . The compressible material layer  24  makes up part of or all of the inside surfaces for the first and second elongate members  30 ,  50  and the interconnecting member  44  while the backing layer  28  makes up the sensor holder&#39;s outside surface. As shown, the compressible material layer  24  does not extend to the ends of the first and second elongate members  30 ,  50 , however, it will be appreciated that in alternative embodiments the compressible material layer may fully cover the inside surface of the elongate members  30 ,  50 . The compressible material layer  24  provides for a gentle patient interface while the backing layer  28  provides light blocking qualities and structural integrity for the dual connection sensor holder  20 . 
     Formed into the compressible material layer  24  on the first elongate member  30  are first and second recesses  70  and  80 . These recesses  70 ,  80  are used to selectively receive a sensor  100  and hold that sensor  100  relative to a patients tissue upon application of the flexible sensor holder  20  to a patient&#39;s extremity. As shown, the sensor  100  is an L-shaped transmittance type pulse oximetry sensor that contains an emitter  104  and detector  102  interconnected by a flexible wiring conduit  106  and a cable  108  interconnecting the sensor  100  to a pulse oximetry monitor (not shown). 
     The flexible sensor holder&#39;s first and second elongate members  30 ,  50  each contain a hook and loop connector for connecting the first and second elongate members  30 ,  50  about a patient&#39;s extremity. The connectors comprise a plurality of hooks  40 ,  42  located on the inside surface of a first portion  36 ,  56  of each elongate member  30 ,  50  and a corresponding plurality of loops  41 ,  43  (shown in phantom) are located along a portion of the length of the outside surface  7  of each elongate member. The loops  41 ,  43  located on the elongate member&#39;s outside surfaces may be formed as a strip aligned with that member&#39;s longitudinal axis, thus providing means for adjusting each elongate member  30 ,  50  to fit about extremities of varying sizes. Though described as a hook and loop connector, it will be appreciated that any appropriate connector means (e.g., tapes, snaps, etc.) may be utilized. 
     The two elongate members  30 ,  50  may be connected around two portions of a patient&#39;s extremity thereby providing a dual connection sensor holder  20  that provides increased sensor holding force. As will be appreciated, by increasing the holding force, motion between the sensor  100  and the tissue may be reduced and, thus, provide for enhanced sensor readings. Alternatively, the force exerted by each elongate member  30 ,  50  may be reduced in comparison to a flexible sensor holder utilizing a single elongate member while still adequately securing the sensor  100  to the patient&#39;s tissue. This is especially desirable in cases where the patient has sensitive skin, such as premature infants. Additionally, tightly wrapping the sensor holder may affect blood flow within the tissue and, therefore, distort sensor readings. 
     The dual connection flexible sensor holder  20  may be utilized to secure a sensor  100  to any patient extremity. However, the configuration of the dual connection flexible sensor holder  20  of the present embodiment is especially apt for holding a sensor  100  on a patient&#39;s foot and leg/ankle. To facilitate conformance to the foot/ankle, the interconnecting member  44  contains an aperture  48  that is located and sized to receive a patient&#39;s heel upon application of the dual connection sensor holder  20  to the patient&#39;s foot and ankle (See  FIGS. 3   a  and  3   b ). In this regard, the first elongate member  30  and second elongate member  50  are conformably wrapped and secured around the patient&#39;s forefoot and the ankle, respectively. 
     In order to apply the sensor holder to the patient&#39;s foot, the ends  34 ,  54  of each elongate member  30 ,  50  which do not contain hooks on their inside surfaces are conformed about the patient&#39;s foot/ankle such that the plurality of loops  41 ,  43  on their outside surface are exposed. Then, the end  36 ,  56  of each elongate member  30 ,  50  containing a plurality of hooks  40 ,  42  on their inside surface, are pulled over the corresponding loops  41 ,  43 , securely attaching each elongate member  30 ,  50  about the extremity. This arrangement creates a sensor holding “bootie” or “sandal” wrap on the patient&#39;s foot and ankle where the first and second elongate members  30 ,  50  securely fasten about the patient&#39;s ankle and foot in two transverse planes. When utilized with a patient&#39;s foot and ankle, the dual connection flexible sensor holder  20  provides enhanced resistance to accidental removal and/or slippage. As will be appreciated, this is particularly important in neonatal and infant applications, as these patients are unable to control their movements and therefore apt to dislodging sensors. 
     As shown in phantom lines in  FIGS. 3   a  and  3   b , when applied to a patient&#39;s foot, the first and second sensor recesses  70 ,  80  are located on the inside and outside edge of the foot, providing a medical technician flexibility in sensor placement. As will be appreciated, it is generally desirable to utilize the thinnest part of the foot (e.g., the outside edge) to obtain better optical communications between the emitter  104  and detector  102  when using a transmittance type pulse oximetry sensor  100 . As shown in  FIG. 3B , the sensor  100  is held by the second recess  80  on the thinner outside edge of the patient&#39;s foot. By providing a sensor holder  20  with two spaced recesses  70 ,  80 , the sensor holder  20  can hold a sensor  100  relative to the inside or outside edge of a patient&#39;s foot regardless of which foot the holder  20  is applied, providing a bootie holder that is non right/left extremity specific. 
     Referring to  FIGS. 1 ,  2 ,  4  and  5 , there is shown the selective removal of the first elongate member  30  from the dual connection sensor holder  20 , effectively converting the dual connection sensor holder  20  or “bootie” wrap of the first embodiment ( FIG. 1 ) to a single connection sensor holder  90  shown in  FIGS. 2 and 5 . In this regard, the bootie wrap&#39;s first elongate member  30 , which contains the first and second recesses  70 ,  80 , is releaseably attached to the interconnecting member  44 . As shown in  FIGS. 1 and 4 , the interface between the interconnecting member  44  and the first elongate member  30  contains a plurality of perforations  46 . These perforations  46  extend through the flexible sensor holder  20  from the inside surface through the outside surface, enabling a medical technician to “tear” the first elongate member  30  away from the interconnecting member  44  when a single connection sensor holder  90  is desired. As shown in  FIG. 2 , this leaves a single connection sensor holder  90  having one elongate member  30  containing first and second recesses  70 ,  80 , and a hook and loop connector  40 ,  41  for connecting the elongate member  30  about a patient&#39;s extremity. This single connection sensor holder  90  as shown in  FIG. 2  may be used to hold a sensor  100  to a patient&#39;s hand as shown in  FIG. 5 , or any other extremity, such as a forearm, ankle, etc. Though shown as a removable portion of the dual connection sensor holder  20 , it will be appreciated that the single connection sensor holder  90  may be separately produced. 
     The recesses  70 ,  80  (See  FIGS. 1 and 2 ) are disposed in a spaced relationship in first and second positions on the elongate member  30 . As shown in  FIGS. 1 and 2  the recesses are entirely separated such that either recess (or possibly both recesses) may be selectively utilized to hold a sensor  100  relative to a first or second position along the elongate member  30 . For simplicity, the rest of the discussion regarding the recesses will be directed to the single connection sensor holder  90  of  FIG. 2 , however, it will be appreciated that the following description is applicable to dual connection sensor holder  20  of  FIG. 1 . Each recess  70 ,  80  further comprise a first and second interconnected portions  72 ,  74  and  82 ,  84  respectively. The recesses  70 ,  80  are formed generally in the shape of an “L” to correspond with the L-shaped pulse oximetry sensor  100 . In this regard, the first portion  74 ,  84  of each recess  70 ,  80  extends along a portion of the length of the elongate member  30 , while the second interconnecting portions  72 ,  82  extend across a portion of the width of the elongate member  90 . These second recess portions  72 ,  82  provide access for the sensor&#39;s cable  108  beneath the elongate member  30  when the elongate member is applied to a patient&#39;s extremity, as shown in relation to the dual connection sensor holder  20  in  FIG. 3   b.    
     As will be appreciated, these second or “access” portions  72 ,  82  of each recess  70 ,  80  allow a sensor cable  108  to exit the sensor holder  90  without applying pressure to the patient&#39;s tissue. Further, these access recess portions  72 ,  82  may extend to different lateral edges  92 ,  94  to provide a sensor holder  90  that allows a sensor cable  108  to be selectively routed out of either lateral edge  92 ,  94  of the sensor holder. As shown in  FIGS. 3   a  and  3   b  for the two elongate member sensor holder  20 , the sensor cable  108  exits the sensor holder  20  from the front. By utilizing the other recess to hold the sensor  100 , the cable  108  could exit toward the heel of the foot. As will be appreciated, in cases where the patient has sensitive tissue (e.g., premature infants) it is generally desirable to direct the cable  108  away from the patient. In contrast, for less sensitive patients it may be desirable to route the sensor cable  108  toward the patient where it may be affixed (e.g. taped) to prevent the cable  108  from pulling on the sensor  100  during patient movement. 
     In the case of the single connection sensor holder  90 , the sensor cable  108  can be routed forward or backward from either recess  70 ,  80  by turning the holder  90  around such that each recess&#39; access opening is in the desired direction. However, the overlap created by one end of the elongate member  30  being secured over a second end of the elongate member  30  creates a flap that may cause patient irritation or provide means for a patient to dislodge the sensor holder  90 . Therefore, it may be desirable to orient this flap in a particular location. As shown in  FIGS. 2 and 5  the second end  34  of the elongate member  30  is placed against the palm of the patient&#39;s hand and the first end  36  is connected over the second end  34  to secure the single connection sensor holder  90  to the patient&#39;s hand. This connection creates a flap  95  where the first end  36  overlaps the second end  34 . In order to orient this flap  95  in a desired direction (e.g., in the palm of the hand with the flap end away from the thumb) and route the sensor cable  108  a particular direction (i.e., forward or backward), two sensor recesses  70 ,  80  with openings to opposite lateral edges of the sensor holder  90  are required. 
       FIG. 6  shows an alternate embodiment of the flexible sensor holder of  FIG. 1 . The sensor holder of  FIG. 6  is substantially identical to the sensor holder of  FIG. 1  except for the shape of the sensor recesses  120 ,  130 . Accordingly, like features are labeled with like numbers. In this embodiment, the first and second recesses  120 ,  130  generally define a T-shape wherein a portion of each recess extends from a first lateral edge to a second lateral edge on the elongate member  30  while a second portion extends along the length of the elongate member  30 . The T-shaped recesses  120 ,  130  may be utilized with the T-shaped sensor  140  shown. As will be appreciated, in this embodiment, the T-shaped sensor  140  may be applied to either recess  120 ,  130  while its cable  148  is routed forward or backwards from either recess  120   130 , thus, further facilitating sensor positioning. As with the embodiment shown in  FIG. 1 , the elongate member  30  having the T-shaped recesses  120 ,  130  may be selectively removed from the H-shaped flexible sensor holder  20  to provide a single connection sensor holder. 
       FIGS. 7   a ,  7   b  and  7   c  show alternative means for securing a sensor  100  to the recesses utilized with any of the above described flexible sensor holders. In one embodiment, the bottom of a recess  70  is coated with an adhesive  97  for selectively adhering a sensor  100  within that recess  70 . This adhesive  97  is covered by a peel away release sheet  96  that may be removed prior to sensor adhesion. This release sheet  96  prevents the adhesive  97  from contacting and possibly irritating a patient&#39;s tissue.  FIGS. 7   b  and  7   c  show an alternate sensor retention means that utilizes two sensor retention slits  160  and  162  formed in the bottom on an L-shaped sensor recess  70 . These retention slits pass through the flexible sensor holder from its inside surface to its outside surface. When utilized with the L-Shaped sensor  100 , the sensor is inserted through the first retention slit  160  from the top surface and back through the second retention slit  162  from the sensor holder&#39;s bottom surface until the sensor  100  seats within the recess ( FIG. 7   c ). As will be appreciated, once the flexible sensor holder  20  is applied to a patient&#39;s tissue, the sensor  100  is securely fastened to the sensor holder without the use of any adhesives. 
       FIG. 8  shows another embodiment of a dual connection sensor holder of the present invention for use with the L-shaped pulse oximetry sensor  100 . The flexible holder  200  includes a first elongate member  230  for conformably wrapping around a first portion of a patient&#39;s extremity, a second elongate member  250  for conformably wrapping around a second portion of a patient&#39;s extremity, and an interconnecting member  240 , containing a “heel” aperture  248 , that interconnects the first and second elongate members  230 ,  250 . The interconnecting member  240  connects the two substantially parallel elongate members  230 ,  250  such that the flexible sensor holder  200  generally comprises a U-shape prior to application to a patient&#39;s extremity. 
     The sensor holder  200  contains a compressible material layer  224  that makes up the sensor holder&#39;s patient interface surface. This compressible material may be formed from foam, neoprene, rubber, fabric, composites thereof and other suitable materials as long as the compressible material has a plurality of void spaces within its structure to permit compression. In this regard, all that is required is that the compressible materials have a compression setting that, upon application of a predetermined pressure to the material, substantially conforms to the surface contacting the compressible material. The sensor holder  200  also contains two separate backing strips  232  and  252  releaseably interconnected to the outside surface of each elongate member  230  and  250 , respectively. As will be appreciated, in this embodiment the interconnecting member  248  contains no backing layer. 
       FIG. 9  shows an exploded cross sectional view taken along section lines A–A′ of  FIG. 8  (not to scale). As shown the backing strip  252  is formed from a hook and loop tape having an inside surface covered by a plurality of hooks  254  and an outside surface covered by a plurality of matching loops  256 . The compressible material layer  224  comprises a two-layer structure that contains an open cell foam layer  260  affixed (e.g., glued, sonically welded, etc.) to a layer of loop material  262 . Accordingly, when the sensor holder  200  is manufactured, the backing layer hooks  254  are releaseably laminated to the compressible material layer&#39;s loop material  262 . As will be appreciated, this provides a secure connection between the compressible material layer  224  the backing strip  252  without the use of additional adhesives or processing steps, thereby providing a simplified production process. 
     Referring to  FIG. 9 , it will be noted that the backing strips  232 ,  252  extend beyond the end of the compressible material layer  224  of each elongate member  230 ,  250 . This enables the exposed hooks  254  on each backing strip&#39;s inside surface to engage the loops  256  contained along the length of their outside surfaces when the elongate members  230  and  250  are wrapped around a patient&#39;s extremity. As will be appreciated, these hooks  254  may engage the loops  256  anywhere along the length of the backing strips  232 ,  252  providing enhanced adjustability to accommodate extremities of varying sizes. Further, the use of hook and loop tape backing strips  232 ,  252  eliminates the need for a separate connector reducing the sensor holder&#39;s overall part count. 
     The use of the hooks and loops to releaseably laminate the backing strips  232 ,  252  to the compressible material  224  provides an additional benefit, namely the ability to adjust (e.g. shorten) the length of each elongate member  230  and  250 . That is, by separating the compressible material  224  from the backing strips  232 ,  252 , the compressible material  224  and backing strips  232 ,  252  may be trimmed to a desired length. That is, the right side of the elongate members  230  and  250  as shown in  FIG. 8  may be shortened. After trimmed to their desired length, the elongate members  230  and  250  may be re-laminated and may be applied to a patient&#39;s extremity. 
     Formed into the compressible material layer  224  on the first elongate member  230  are first and second sensor holding recesses  270  and  280 . Again, these recesses  270 ,  280  are used to selectively receive an L-shaped pulse oximetry sensor  100  and hold that sensor  100  relative to a patients tissue upon application of the flexible sensor holder  200  to a patient&#39;s extremity. As shown, each sensor holding recess  270 ,  280  comprises two separated recess portions ‘A’ and ‘B’ that are formed by cutting out and removing sections of the compressible material layer  224 . A portion ‘B’ of each recess  270 ,  280  is shown aligned with along the first elongate member&#39;s center line and is sized to receive the emitter portion  104  of the pulse oximetry sensor  100  while the second portion ‘A’ of each recess  270 ,  280  is sized to receive the detector portion  102  of the pulse oximetry sensor  100 . In this embodiment, the first and second recess portions ‘A’ and ‘B’ are separated by a section of compressible material  224  that forms sensor a retaining member  276 . 
     To enable the L-shaped sensor  100  to be inserted into one the recesses  270 ,  280 , the backing strip  232  beneath each recess portion ‘A’ and ‘B’ contains sensor retention slits  160 ,  162 . In this regard, the emitter  104  is inserted through the first slit  160  from the topside of the sensor holder  200 . The emitter  104  is then routed through the second slit  162  from the backside of the sensor holder  200  until the emitter  104  seats in the second recess. At this point, the sensor&#39;s detector  102  is seated in the sensor recess portion ‘A’ and the emitter  104  is seated within sensor recess portion ‘B.’ More importantly, the flexible wiring conduit  106  interconnecting the emitter  104  and detector  102  is trapped behind both the backing strip  232  and compressible material layer  224  between the slits  160 ,  162 . As will be appreciated, this “weaved” arrangement securely fastens the sensor  100  within the sensor holder  200  without the need for any adhesives that may contact or otherwise irritate the patient&#39;s tissue. 
     As with the embodiments described above, the U-shaped flexible sensor holder  200  may be utilized to provide a dual point connection on any patient extremity, however, this configuration is again particularly apt for placement on a patient&#39;s foot and ankle. In this regard, after a sensor is inserted within one of the sensor holding recesses  270 ,  280  a patient&#39;s foot would be placed on the flexible sensor holder  200  having the heel centered within the interconnecting member&#39;s aperture  248  with the patient&#39;s toes extending past the sensor holding recesses  270  and  280 . The first elongate member  230  would then be wrapped around the patient&#39;s forefoot until the hooks on the backing strip&#39;s inside surface engage the loops on its outside surface. The second elongate member  250  would then be affixed about the patient&#39;s ankle/lower leg. In application, the U-shaped sensor holder  200  is substantially similar to the H-shaped sensor holder shown in  FIGS. 3   a  and  3   b.    
     While various embodiments of the present invention have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention, as set forth in the following claims.