WO2005114185A2

WO2005114185A2 - Integrated glucose monitors and measurement of analytes via molecular oxygen modulation of dye fluorescence lifetime

Info

Publication number: WO2005114185A2
Application number: PCT/US2005/017886
Authority: WO
Inventors: Tom Shulte; David Cullen; Michael J. Owen
Original assignee: Pelikan Technologies, Inc.
Priority date: 2004-05-20
Filing date: 2005-05-20
Publication date: 2005-12-01
Also published as: WO2005114185A3; EP1766371A4; EP1766371A2

Abstract

Methods and apparatus are provided for an analyte detecting device. In one embodiment, the apparatus comprises an analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; with hydrophobic phase to hydrophilic phase volume ratios of 2:1.

Description

INTEGRATED GLUCOSE MONITORS AND MEASUREMENT OF ANALYTES VIA MOLECULAR OXYGEN MODULATION OF DYE FLUORESCENCE LIFETIME

BACKGROUND OF THE INVENTION Technical Field: The technical field relates to analyte detecting devices, and more specifically, to the chemistry used in analyte detecting devices. Background Art: Test strips are known in the medical health-care products industry for analyzing analyte levels such as but not limited to, glucose levels in blood. For this type of analysis, a drop of blood is typically obtained by making a small incision in the fingertip, creating a small wound, which generates a small blood droplet on the surface of the skin, A test strip is brought by the user to the blood droplet at the wound and engaged in a manner to bring blood to an analysis site on the test strip. The test strip is then coupled to a metering device which typically uses an electrochemical technique to determine the amount of glucose in the blood. Early methods of using test strips required a relatively substantial volume of blood to obtain an accurate glucose measurement. This large blood requirement made the monitoring experience a painful one for the user since the user may need to lance deeper than comfortable to obtain sufficient blood generation. Alternatively, if insufficient blood is spontaneously generated, the user may need to "milk" the wound to squeeze enough blood to the skin surface. Neither method is desirable as they take additional user effort and may be painful. The discomfort and inconvenience associated with such lancing events may deter a user from testing their blood glucose levels in a rigorous manner sufficient to control their diabetes. A further impediment to patient compliance is the amount of time that it takes for a glucose measurement to be completed. Known devices can take a substantial amount of time to arrive at a glucose level. The more time it takes to arrive at a measurement, the less the likely that the user will stay with their testing regime.

SUMMARY OF THE INVENTION The present invention provides solutions for at least some of the drawbacks discussed above. Specifically, some embodiments of the present invention provide an improved apparatus for measuring analyte levels in a body fluid. The present invention also provided improved techniques for emulsions used with such analyte detecting devices. At least some of these and other objectives described herein will be met by embodiments of the present invention. In one embodiment, the apparatus comprises an analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; with hydrophobic phase to hydrophilic phase volume ratios of 2: 1. In one embodiment, the present invention provides measurement of analytes via molecular oxygen modulation of dye fluorescence lifetime. The invention may use optical chemical analyte detecting members comprised of microemulsions. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase, with hydrophobic phase to hydrophilic phase volume ratios of 2 : 1. The device may further comprise a radial cartridge having a plurality of the analyte detecting members. Each of the detecting members may include a diffusion barrier. The detecting members may each include a glucose oxidase hydrogel layer. The detecting members may each include an oxygen sensing fluorophore silicone layer. The detecting members may each include an oxygen sensing fluorophore silicone layer with ruthenium. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase stabilized by non-ionic surfactants as emulsifiers. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase, whereing the non-ionic surfactant has an HLB of >15. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase, wherein the hydrophilic phase is cross-linked. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase wherein the hydrophilic phase contains an enzyme or other biological entity that reacts with a target analyte and, in a reproducible way, affects a second chemical moiety that can be sensed in the hydrophobic phase. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase, wherein the sensing means is a fluorescent dye responsive to the concentration of the second chemical moiety. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase, wherein the state of the fluorescent dye can be monitored by intensity or by lifetime changes. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase, wherein the hydrophilic and hydrophobic phases are cross-linked by a photo-initiated crosslinker. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members having at least one microemulsion wherein one phase as an emulsion is dispersed within another. Li another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received by at least one of the detecting members and drawn through a diffusion barrier into a enzyme hydrogel layer. The members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye. The analyte detecting members may be arranged in an array. In another embodiment of the present invention, an analyte detecting member is provided that comprises of optical chemical analyte detecting members comprised of at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received by at least one of the detecting members and drawn through a diffusion barrier into a enzyme hydrogel layer; wherein the members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye; wherein the analyte detecting members are arranged in an array inside a fluid pathway this is serpentine in shape. hi another embodiment of the present invention, a device is provided comprising a disc containing a plurality of penetrating members; optical chemical analyte detecting members coupled to the disc and each detecting member having at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received by at least one of the detecting members and drawn through a diffusion barrier into a enzyme hydrogel layer; wherein the members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye; wherein the analyte detecting members are arranged in an array. A further understanding of the nature and advantages of the invention will become apparent by reference to the remaining portions of the specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates an embodiment of a controllable force driver in the for of a cylindrical electric penetrating member driver using a coiled solenoid -type configuration. Figure 2A illustrates a displacement over time profile of a penetrating member driven by a harmonic spring/mass system. Figure 2B illustrates the velocity over time profile of a penetrating member driver by a harmonic spring/mass system. Figure 2C illustrates a displacement over time profile of an embodiment of a controllable force driver. Figure 2D illustrates a velocity over time profile of an embodiment of a controllable, force driver. Figure 3 is a diagrammatic view illustrating a controlled feed-back loop. Figure 4 is a perspective view of a tissue penetration device having features of the invention. Figure 5 is an elevation view in partial longitudinal section of the tissue penetration device of Figure 4. Figure 6 shows a cutaway perspective view of one embodiment of the device according to the present invention. Figures 7 and 8 are charts showing HLB emulsion characteristics. Figures 9 and 10 show embodiments of arrays according to the present invention. Figure 11 is a cross-section view of a structure according to the present invention. Figure 12 shows an embodiment of the present invention. Figures 13 A and 13B show embodiments of the present invention. Figure 14 shows a disposable that may incorporate optical detecting members according to the present invention. DESCRIPTION OF THE SPECIFIC EMBODIMENTS It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. It may be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a material" may include mixtures of materials, reference to "a chamber" may include multiple chambers, and the like. References cited herein are hereby incorporated by reference in their entirety, except to the extent that they conflict with teachings explicitly set forth in this specification. In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings: "Optional" or "optionally" means that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. For example, if a device optionally contains a feature for analyzing a blood sample, this means that the analysis feature may or may not be present, and, thus, the description includes structures wherein a device possesses the analysis feature and structures wherein the analysis feature is not present. The present invention may be used with a variety of different penetrating member drivers. It is contemplated that these penetrating member drivers may be spring based, solenoid based, magnetic driver based, nanomuscle based, or based on any other mechanism useful in moving a penetrating member along a path into tissue. It should be noted that the present invention is not limited by the type of driver used with the penetrating member feed mechanism. One suitable penetrating member driver for use with the present invention is shown in Figure 1. This is an embodiment of a solenoid type electromagnetic driver that is capable of driving an iron core or slug mounted to the penetrating member assembly using a direct current (DC) power supply. The electromagnetic driver includes a driver coil pack that is divided into three separate coils along the path of the penetrating member, two end coils and a middle coil. Direct current is alternated to the coils to advance and retract the penetrating member. Although the driver coil pack is shown with three coils, any suitable number of coils maybe used, for example, 4, 5, 6, 7 or more coils may be used. Referring to the embodiment of Figure 1, the stationary iron housing 10 may contain the driver coil pack with a first coil 12 flanked by iron spacers 14 which concentrate the magnetic flux at the inner diameter creating magnetic poles. The inner insulating housing 16 isolates the penetrating member 18 and iron core 20 from the coils and provides a smooth, low friction guide surface. The penetrating member guide 22 further centers the penetrating member 18 and iron core 20. The penetrating member 18 is protracted and retracted by alternating the current between the first coil 12, the middle coil, and the third coil to attract the iron core 20. Reversing the coil sequence and attracting the core and penetrating member back into the housing retracts the penetrating member. The penetrating member guide 22 also serves as a stop for the iron core 20 mounted to the penetrating member 18. As discussed above, tissue penetration devices which employ spring or cam driving methods have a symmetrical or nearly symmetrical actuation displacement and velocity profiles on the advancement and retraction of the penetrating member as shown in Figures 2 and 3. In most of the available lancet devices, once the launch is initiated, the stored energy determines the velocity profile until the energy is dissipated. Controlling impact, retraction velocity, and dwell time of the penetrating member within the tissue can be useful in order to achieve a high success rate while accommodating variations in skin properties and minimize pain. Advantages can be achieved by taking into account of the fact that tissue dwell time is related to the amount of skin deformation as the penetrating member tries to puncture the surface of the skin and variance in skin defoπnation from patient to patient based on skin hydration. In this embodiment, the ability to control velocity and depth of penetration may be achieved by use of a controllable force driver where feedback is an integral part of driver control. Such drivers can control either metal or polymeric penetrating members or any other type of tissue penetration element. The dynamic control of such a driver is illustrated in Figure. 2C which illustrates an embodiment of a controlled displacement profile and Figure 2D which illustrates an embodiment of a the controlled velocity profile. These are compared to Figures 2A and 2B, which illustrate embodiments of displacement and velocity profiles, respectively, of a harmonic spring/mass powered driver. Reduced pain can be achieved by using impact velocities of greater than about 2 m/s entry of a tissue penetrating element, such as a lancet, into tissue. Other suitable embodiments of the penetrating member driver are described in commonly assigned, copending U.S. Patent Application Ser. No. 10/127,395, (Attorney Docket No. 38187- 2551) filed April 19, 2002 and previously incorporated herein. Figure 3 illustrates the operation of a feedback loop using a processor 60. The processor 60 stores profiles 62 in non- volatile memory. A user inputs information 64 about the desired circumstances or parameters for a lancing event. The processor 60 selects a driver profile 62 from a set of alternative driver profiles that have been preprogrammed in the processor 60 based on typical or desired tissue penetration device performance determined through testing at the factory or as programmed in by the operator. The processor 60 may customize by either scaling or modifying the profile based on additional user input information 64. Once the processor has chosen and customized the profile, the processor 60 is ready to modulate the power from the power supply 66 to the penetrating member driver 68 through an amplifier 70. The processor 60 may measure the location of the penetrating member 72 using a position sensing mechanism 74 through an analog to digital converter 76 linear encoder or other such transducer. Examples of position sensing mechanisms have been described in the embodiments above and may be found in the specification for commonly assigned, copending U.S. Patent Application Ser. No. 10/127,395, (Attorney Docket No. 38187-2551) filed April 19, 2002 and previously incorporated herein. The processor 60 calculates the movement of the penetrating member by comparing the actual profile of the penetrating member to the predetermined profile. The processor 60 modulates the power to the penetrating member driver 68 through a signal generator 78, which may control the amplifier 70 so that the actual velocity profile of the penetrating member does not exceed the predetermined profile by more than a preset error limit. The error limit is the accuracy in the control of the penetrating member. After the lancing event, the processor 60 can allow the user to rank the results of the lancing event. The processor 60 stores these results and constructs a database 80 for the individual user. Using the database 79, the processor 60 calculates the profile traits such as degree of painlessness, success rate, and blood volume for various profiles 62 depending on user input information 64 to optimize the profile to the individual user for subsequent lancing cycles. These profile traits depend on the characteristic phases of penetrating member advancement and retraction. The processor 60 uses these calculations to optimize profiles 62 for each user. In addition to user input information 64, an internal clock allows storage in the database 79 of information such as the time of day to generate a time stamp for the lancing event and the time between lancing events to anticipate the user's diurnal needs. The database stores information and statistics for each user and each profile that particular user uses. In addition to varying the profiles, the processor 60 can be used to calculate the appropriate penetrating member diameter and geometry suitable to realize the blood volume required by the user. For example, if the user requires about 1-5 microliter volume of blood, the processor 60 may select a 200 micron diameter penetrating member to achieve these results. For each class of penetrating member, both diameter and penetrating member tip geometry, is stored in the processor 60 to correspond with upper and lower limits of attainable blood volume based on the predetermined displacement and velocity profiles. The lancing device is capable of prompting the μser for information at the beginning and the end of the lancing event to more adequately suit the user. The goal is to either change to a different profile or modify an existing profile. Once the profile is set, the force driving the penetrating member is varied during advancement and retraction to follow the profile. The method of lancing using the lancing device comprises selecting a profile, lancing according to the selected profile, determining lancing profile traits for each characteristic phase of the lancing cycle, and optimizing profile traits for subsequent lancing events. Figure 4 illustrates an embodiment of a tissue penetration device, more specifically, a lancing device 80 that includes a controllable driver 179 coupled to a tissue penetration element. The lancing device 80 has a proximal end 81 and a distal end 82. At the distal end 82 is the tissue penetration element in the form of a penetrating member 83, which is coupled to an elongate coupler shaft 84 by a drive coupler 85. The elongate coupler shaft 84 has a proximal end 86 and a distal end 87. A driver coil pack 88 is disposed about the elongate coupler shaft 84 proximal of the penetrating member 83. A position sensor 91 is disposed about a proximal portion 92 of the elongate coupler shaft 84 and an electrical conductor 94 electrically couples a processor 93 to the position sensor 91. The elongate coupler shaft 84 driven by the driver coil pack 88 controlled by the position sensor 91 and processor 93 form the controllable driver, specifically, a controllable electromagnetic driver. Referring to Figure 5, the lancing device 80 can be seen in more detail, in partial longitudinal section. The penetrating member 83 has a proximal end 95 and a distal end 96 with a sharpened point at the distal end 96 of the penetrating member 83 and a drive head 98 disposed at the proximal end 95 of the penetrating member 83. A penetrating member shaft 201 is disposed between the drive head 98 and the sharpened point 97. The penetrating member shaft 201 may be comprised of stainless steel, or any other suitable material or alloy and have a transverse dimension of about 0.1 to about 0.4 mm. The penetrating member shaft may have a length of about 3 mm to about 50 mm, specifically, about 15 mm to about 20 mm. The drive head 98 of the penetrating member 83 is an enlarged portion having a transverse dimension greater than a transverse dimension of the penetrating member shaft 201 distal of the drive head 98. This configuration allows the drive head 98 to be mechanically captured by the drive coupler 85. The drive head 98 may have a transverse dimension of about 0.5 to about 2 mm. A magnetic member 102 is secured to the elongate coupler shaft 84 proximal of the drive coupler 85 on a distal portion 203 of the elongate coupler shaft 84. The magnetic member 102 is a substantially cylindrical piece of magnetic material having an axial lumen 204 extending the length of the magnetic member 102. The magnetic member 102 has an outer transverse dimension that allows the magnetic member 102 to slide easily within an axial lumen 105 of a low friction, possibly lubricious, polymer guide tube 105' disposed within the driver coil pack 88. The magnetic member 102 may have an outer transverse dimension of about 1.0 to about 5.0 mm, specifically, about 2.3 to about 2.5 mm. The magnetic member 102 may have a length of about 3.0 to about 5.0 mm, specifically, about 4.7 to about 4.9 mm. The magnetic member 102 can be made from a variety of magnetic materials including ferrous metals such as ferrous steel, iron, ferrite, or the like. The magnetic member 102 may be secured to the distal portion 203 of the elongate coupler shaft 84 by a variety of methods including adhesive or epoxy bonding, welding, crimping or any other suitable method. Proximal of the magnetic member 102, an optical encoder flag 206 is secured to the elongate coupler shaft 84. The optical encoder flag 206 is configured to move within a slot 107 in the position sensor 91. The slot 107 of the position sensor 91 is formed between a first body portion 108 and a second body portion 109 of the position sensor 91. The slot 107 may have separation width of about 1.5 to about 2.0 mm. The optical encoder flag 206 can have a length of about 14 to about 18 mm, a width of about 3 to about 5 mm and a thickness of about 0.04 to about 0.06 mm. The optical encoder flag 206 interacts with various optical beams generated by LEDs disposed on or in the position sensor body portions 108 and 109 in a predetermined manner. The interaction of the optical beams generated by the LEDs of the position sensor 91 generates a signal that indicates the longitudinal position of the optical flag 206 relative to the position sensor 91 with a substantially high degree of resolution. The resolution of the position sensor 91 may be about 200 to about 400 cycles per inch, specifically, about 350 to about 370 cycles per inch. The position sensor 91 may have a speed response time (position/time resolution) of 0 to about 120,000 Hz, where one dark and light stripe of the flag constitutes one Hertz, or cycle per second. The position of the optical encoder flag 206 relative to the magnetic member 102, driver coil pack 88 and position sensor 91 is such that the optical encoder 91 can provide precise positional information about the penetrating member 83 over the entire length of the penetrating member's power stroke. An optical encoder that is suitable for the position sensor 91 is a linear optical incremental encoder, model HEDS 9200, manufactured by Agilent Technologies. The model HEDS 9200 may have a length of about 20 to about 30 mm, a width of about 8 to about 12 mm, and a height of about 9 to about 11 mm. Although the position sensor 91 illustrated is a linear optical incremental encoder, other suitable position sensor embodiments could be used, provided they posses the requisite positional resolution and time response. The HEDS 9200 is a two channel device where the channels are 90 degrees out of phase with each other. This results in a resolution of four times the basic cycle of the flag. These quadrature outputs make it possible for the processor to determine the direction of penetrating member travel. Other suitable position sensors include capacitive encoders, analog reflective sensors, such as the reflective position sensor discussed above, and the like. A coupler shaft guide 111 is disposed towards the proximal end 81 of the lancing device 80. The guide 111 has a guide lumen 112 disposed in the guide 111 to slidingly accept the proximal portion 92 of the elongate coupler shaft 84. The guide 111 keeps the elongate coupler shaft 84 centered horizontally and vertically in the slot 102 of the optical encoder 91. Referring now to Figure 6, a still further embodiment of a cartridge according to the present invention will be described. Figure 6 shows one embodiment of a cartridge 300 which may be removably inserted into an apparatus for driving penetrating members to pierce skin or tissue. The cartridge 300 has a plurality of penetrating members 302 that may be individually or otherwise selectively actuated so that the penetrating members 302 may extend outward from the cartridge, as indicated by arrow 304, to penetrate tissue. In the present embodiment, the cartridge 300 may be based on a flat disc with a number of penetrating members such as, but in no way limited to, (25, 50, 75, 100, ...) arranged radially on the disc or cartridge 800. It should be understood that although the cartridge 300 is shown as a disc or a disc-shaped housing, other shapes or configurations of the cartridge may also work without departing from the spirit of the present invention of placing a plurality of penetrating members to be engaged, singly or in some combination, by a penetrating member driver. Each penetrating member 302 may be contained in a cavity 306 in the cartridge 300 with the penetrating member's sharpened end facing radially outward and may be in the same plane as that of the cartridge. The cavity 306 may be molded, pressed, forged, or otherwise formed in the cartridge. Although not limited in this manner, the ends of the cavities 306 may be divided into individual fingers (such as one for each cavity) on the outer periphery of the disc. The particular shape of each cavity 306 may be designed to suit the size or shape of the penetrating member therein or the amount of space desired for placement of the analyte detecting members 808. For example and not limitation, the cavity 306 may have a V-shaped cross-section, a U-shaped cross- section, C-shaped cross-section, a multi-level cross section or the other cross-sections. The opening 810 through which a penetrating member 302 may exit to penetrate tissue may also have a variety of shapes, such as but not limited to, a circular opening, a square or rectangular opening, a U-shaped opening, a narrow opening that only allows the penetrating member to pass, an opening with more clearance on the sides, a slit, a configuration as shown in Figure 75, or the other shapes. In this embodiment, after actuation, the penetrating member 302 is returned into the cartridge and may be held within the cartridge 300 in a manner so that it is not able to be used again. By way of example and not limitation, a used penetrating member may be returned into the cartridge and held by the launcher in position until the next lancing event. At the time of the next lancing, the launcher may disengage the used penetrating member with the cartridge 300 turned or indexed to the next clean penetrating member such that the cavity holding the used penetrating member is position so that it is not accessible to the user (i.e. turn away from a penetrating member exit opening). In some embodiments, the tip of a used penetrating member may be driven into a protective stop that hold the penetrating member in place after use. The cartridge 300 is replaceable with a new cartridge 300 once all the penetrating members have been used or at such other time or condition as deemed desirable by the user. Referring still to the embodiment in Figure 6, the cartridge 300 may provide sterile environments for penetrating members via seals, foils, covers, polymeric, or similar materials used to seal the cavities and provide enclosed areas for the penetrating members to rest in. In the present embodiment, a foil or seal layer 320 is applied to one surface of the cartridge 300. The seal layer 320 may be made of a variety of materials such as a metallic foil or other seal materials and may be of a tensile strength and other quality that may provide a sealed, sterile environment until the seal layer 320 is penetrate by a suitable or penetrating device providing a preselected or selected amount of force to open the sealed, sterile environment. Each cavity 306 may be individually sealed with a layer 320 in a manner such that the opening of one cavity does not interfere with the sterility in an adjacent or other cavity in the cartridge 800. As seen in the embodiment of Figure 6, the seal layer 320 may be a planar material that is adhered to a top surface of the cartridge 800. Depending on the orientation of the cartridge 300 in the penetrating member driver apparatus, the seal layer 320 may be on the top surface, side surface, bottom surface, or other positioned surface. For ease of illustration and discussion of the embodiment of Figure 6, the layer 320 is placed on a top surface of the cartridge 800. The cavities 306 holding the penetrating members 302 are sealed on by the foil layer 320 and thus create the sterile environments for the penetrating members. The foil layer 320 may seal a plurality of cavities 306 or only a select number of cavities as desired. In a still further feature of Figure 6, the cartridge 300 may optionally include a plurality of analyte detecting members 308 on a substrate 822 which may be attached to a bottom surface of the cartridge 300. The substrate may be made of a material such as, but not limited to, a polymer, a foil, or other material suitable for attaching to a cartridge and holding the analyte detecting members 308. As seen in Figure 6, the substrate 322 may hold a plurality of analyte detecting members, such as but not limited to, about 10-50, 50-100, or other combinations of analyte detecting members. This facilitates the assembly and integration of analyte detecting members 308 with cartridge 300. These analyte detecting members 308 may enable an integrated body fluid sampling system where the penetrating members 302 create a wound tract in a target tissue, which expresses body fluid that flows into the cartridge for analyte detection by at least one of the analyte detecting members 308. The substrate 322 may contain any number of analyte detecting members 308 suitable for detecting analytes in cartridge having a plurality of cavities 306. In one embodiment, many analyte detecting members 308 may be printed onto a single substrate 322 which is then adhered to the cartridge to facilitate manufacturing and simplify assembly. The analyte detecting members 308 may be electrochemical in nature. The analyte detecting members 308 may further contain enzymes, dyes, or other detectors which react when exposed to the desired analyte. Additionally, the analyte detecting members 308 may comprise of clear optical windows that allow light to pass into the body fluid for analyte analysis. The number, location, and type of analyte detecting member 308 may be varied as desired, based in part on the design of the cartridge, number of analytes to be measured, the need for analyte detecting member calibration, and the sensitivity of the analyte detecting members. If the cartridge 300 uses an analyte detecting member arrangement where the analyte detecting members are on a substrate attached to the bottom of the cartridge, there may be through holes (as shown in Figure 76), wicking elements, capillary tube or other devices on the cartridge 300 to allow body fluid to flow from the cartridge to the analyte detecting members 308 for analysis, hi other configurations, the analyte detecting members 308 may be printed, formed, or otherwise located directly in the cavities housing the penetrating members 302 or areas on the cartridge surface that receive blood after lancing. The use of the seal layer 320 and substrate or analyte detecting member layer 822 may facilitate the manufacture of these cartridges 10. For example, a single seal layer 320 may be adhered, attached, or otherwise coupled to the cartridge 300 as indicated by arrows 324 to seal many of the cavities 306 at one time. A sheet 322 of analyte detecting members may also be adhered, attached, or otherwise coupled to the cartridge 300 as indicated by arrows 325 to provide many analyte detecting members on the cartridge at one time. During manufacturing of one embodiment of the present invention, the cartridge 300 may be loaded with penetrating members 302, sealed with layer 320 and a temporary layer (not shown) on the bottom where substrate 322 would later go, to provide a sealed environment for the penetrating members. This assembly with the temporary bottom layer is then taken to be sterilized. After sterilization, the assembly is taken to a clean room (or it may already be in a clear room or equivalent environment) where the temporary bottom layer is removed and the substrate 322 with analyte detecting members is coupled to the cartridge as shown in Figure 6. This process allows for the sterile assembly of the cartridge with the penetrating members 302 using processes and or temperatures that may degrade the accuracy or functionality of the analyte detecting members on substrate 322. As a nonlimiting example, the entire cartridge 300 may then be placed in a further sealed container such as a pouch, bag, plastic molded container, etc...to facilitate contact, improve ruggedness, and/or allow for easier handling. In some embodiments, more than one seal layer 320 may be used to seal the cavities 306. As examples of some embodiments, multiple layers may be placed over each cavity 306, half or some selected portion of the cavities may be sealed with one layer with the other half or selected portion of the cavities sealed with another sheet or layer, different shaped cavities may use different seal layer, or the like. The seal layer 320 may have different physical properties, such as those covering the penetrating members 302 near the end of the cartridge may have a different color such as red to indicate to the user (if visually inspectable) that the user is down to say 10, 5, or other number of penetrating members before the cartridge should be changed out. Referring now to Figures 7 and 8, these embodiments of the present invention relate to chemical -based optical analyte detecting members using emulsions. Some forms of chemical analyte detecting members that use chemical components that individually need disparate phases. This problem of disparate phases (hydrophobic and hydrophilic) is sometimes solved by simply layering one phase over another. But this arrangement can be constraining if one is seeking to design a fast-responding analyte detecting member, and poses problems in manufacture. A better solution to the problem, which is the subject of this application, is to disperse one phase as an emulsion, or micro-emulsion, within the other. One attractive method of monitoring blood glucose content is by oxygen modulation of dye fluorescence lifetime (1). For such a device to operate adequately, it is desired to generate the oxygen in one phase and monitor it in another. Since blood is an aqueous system this means that the oxygen generating phase will be hydrophilic to enable the glucose to diffuse in and affect oxygen concentrations, and the fluorescent dye will be in an adjacent hydrophobic phase. Consequently, at the heart of such a analyte detecting member is an interface between a hydrophobic and a hydrophilic phase. Organosilicon polymers such as but not limited to silicones and related polymers are good potential candidates for the hydrophobic phase because of their excellent oxygen permeability. A variety of hydrogel materials would make possible hydrophilic phases. A number of analyte detecting members of this type have been described where the organosilicon polymer carries a ruthenium complex fluorescent dye and the hydrogel phase contains glucose oxidase (GOX) that consumes oxygen on contact with blood glucose. By way of example and not limitation, there would appear to be two prime advantages to dispersing the hydrophobic phase in the hydrophilic phase, namely to increase measurement sensitivity and to aid in analyte detecting member production. Essentially, what is desired is an emulsion of a dispersed organosilicon phase in a continuous aqueous hydrogel phase. Silicone- in-water emulsions are familiar articles of commerce but little is known either about the emulsification of other organosilicon monomers or about the impact of significant quantities of hydrophilic polymers in the aqueous phase. Silicone-in-water emulsions are usually stabilized by conventional organic emulsifiers, there seems to be no need to employ specialty silicone-based surfactants as are required for water-in-silicone emulsions. Recently, there has been considerable interest in the patent literature (particularly from China and Japan) in emulsions of organosilicon-modified acrylates and methacrylates, related to paints and coatings with improved properties. This literature confirms the adequacy of conventional emulsifiers such as sodium dodecyl sulfate (3) and polyoxyethylene alkyl ether sulfate ammonium salts (4). For our purposes, we were concerned about the potential detrimental impact of ionic surfactants on the biopolymers in our formulations, so have restricted our investigations to nonionic emulsifiers. Not only do conventional organic emulsifiers offer a good point from which to start such an investigation for an improved analyte detecting member but it was further anticipated that conventional emulsification concepts such as the HLB system would also be helpful in this endeavor. HLB stands for hydrophile-lipophile balance and is an essentially empirical scale that indicates the balance between oil soluble and water soluble moieties in the surfactant; the more oil soluble the lower the HLB. Typical water-in-oil emulsifiers have HLB in the range of 4-8, oil-in-water emulsifiers are usually in the range of 11-16. This system enables formulators to match the HLB of an emulsifier with the "preferred" or "required" HLB of any organic oil. For example, the "preferred" HLB of polydimethylsiloxane (PDMS) is 9-11. Compilations of HLB numbers of surfactants are readily available (5). If the "preferred" HLB of a material is unknown, it can be experimentally determined by assessing stability of a series of emulsions prepared using a range of emulsifiers of various HLB. The so-called Spans (sorbitan esters) and Tweens (ethoxylated sorbitan esters) are the best known such surfactant series. Table 1 lists the various hydrophobic monomers we explored together with their calculated solubility parameters, δ.

Table 1 : Hydrophobic monomers No. Name δ (cal/cm3)l/2 1 Trimethylsilylmethylmethacrylate 8.20 2. Acryloxyproρyltris(trimethylsiloxy)silane 7.81 3. Methacryloxypropylpentamethyldisiloxane 8.05 4. l,3-bis(3-methacryloxypropyl)tetrakis- 8.16 (trimethylsiloxy)disiloxane 5 l,3-bis(3-methacryloxypropyl)tetramethyldisiloxane 8.70 Polydimethylsiloxane (PDMS) 7.39 We also explored a variety of hydrogel systems for the continuous aqueous phase. The present application shows examples of results with the poly[(ethylene oxide) methacrylate] (PEGMA)/poly[(ethylene oxide) dimethacrylate] (PEGDA) system but hydroxyethylmethacrylate (HEMA) systems were also investigated. Variables such as but not limited to hydrophobic/hydrophilic phase ratio and surfactant emulsifier concentration were found not to be critically sensitive variables. We typically used a 1 :2 (v/v) hydrophobic to hydrophilic phase ratio and an emulsifier concentration of 1 wt % of the hydrophobic monomers which in all cases (see, for example, Table 2) was well above the CMC (critical micelle concentration) of the surfactant. The emulsions were prepared using a conventional mini- homogenizer (Ultra-Turrax T8, Ika-Werke, Staufen, Germany). The initial studies with Spans and Tweens were not very promising and indicated the need for a range of higher HLB emulsifiers. The widest range of commonly available, non-ionic high-HLB surfactants is the Tergitol 15-S series available from Dow Chemical Company, Midland MI. These are materials with a 15-carbon secondary alcohol hydrophobe precursor with polyoxyethylene hydrophobes of varying chain-length, e.g. 15-S-9 has 9 ethylene oxide (EO) units, 15-S-40 has 40. The series we employed and their HLBs are shown in Table 2. They were used as received. Table 2: Tergitol 15-S Surfactants Designation Cloud point CMC HLB (1% aqueous, °C) (ppm)

15-S-9 60 56 13.3

15-S-12 89 110 14.5

15-S-15 >100 180 15.4

15-S-20 >100 280 16.3

15-S-30 >100 710 17.4

15-S-40 >100 2200 18.0 Figures 7 and 8 are chosen to illustrate some unexpected observations regarding the preparation of these emulsions. Firstly, monomer 1 proved to be much more difficult to emulsify than other monomers. As can be seen from Figure 7 some breaking of the emulsion is evident after only a few hours whereas in a 4:1 ratio of monomer 5 to monomer 1 the emulsion is completely stable for 100 hours (Figure 8). A 100% monomer 5 emulsions behaves very similarly to the 4:1 combination, our interest in mixtures derives from the fluorescence properties of the materials, some monomer 1 content being desired to optimize this aspect. A second unexpected feature is that both the monomer combinations shown in Figures 7 and 8, and in fact all the monomers and combinations we investigated, have maximum stability at the highest HLB emulsifier used. Tergitol 15-S-40 has HLB of 18; had higher HLB emulsifiers been available one wonders whether yet more stable emulsions would be formed and would different "preferred" HLBs have been evident. At present we can only state that the "preferred" HLB of all the monomers is at least 18, i.e. in a much higher HLB region than would have been predicted from their relatively low, hydrophobic, solubility parameters. The emulsions shown in the figures do not contain the oxygen-sensitive fluorescent dye complex in the hydrophobic phase, neither do they contain the photo-initiators or glucose oxidase that are needed in the fully formulated materials. Inclusion of these makes no significant difference to emulsion formulation and stability unless surface active agents are involved. It has proved possible to prepare fully-formulated emulsions of organosilicon-modified acrylates and methacrylates and aqueous hydrogels that are sufficiently stable to be useful in the manufacture of glucose sensing devices. However, conventional HLB-based approaches to formulation of these emulsions do not seem to be very helpful in directing their development. A clear need emerges for more fundamental studies on this type of emulsion.

Referring now to Figure 9, in yet another aspect of the present invention, micro- fabricated biosensor arrays may enable multi-analyte detection and enable increased analytical robustness. This may allow for high-volume production / low unit-cost devices. Figure 9 shows one embodiment of a 1st generation μ-biosensor array test structures 100 (fluorescence photomicrograph). Referring now to Figure 10, another embodiment of the present invention will now be described. Figure 10 shows a 2nd generation μ-biosensor array test structure 110 with μ-fluidic sample delivery. A reverse S shaped fluid path 112 is shown with the test structure 110. Other embodiments may use a normal S shaped path or other single or multiple curved path. One end of the pathway may be open to receiving the body fluid or blood via a sample capture opening. The sample capture may use capillary action, mesh, and/or wicking to draw fluid into the pathway. Embodiments of the present invention may be manufacturable and to scale-up from low- yield, low-throughput manual fabrication in a commercial environment. This may allow for automated, high-throughput, low unit-cost mass-manufacture and retain appropriate analytical performance and compliance within regulatory frameworks. In one embodiment, the present invention provides enzyme coupled oxygen modulation of fluorescence dye lifetime measurement. The dyes fluorescence output is determined through quantum yield and excited state lifetime modulated by local molecular oxygen concentration. Use of fluorescence dye lifetime measurement allows for tolerance to variation in absolute dye amount. The present invention is compatible with a range of molecular oxygen consuming enzyme systems. Spinout of optoelectronics technology from telecoms R&D may enable a low- cost handheld reader. In another embodiment, the present invention provides a micro-emulsion approach to dye and enzyme immobilization. This gives favorable and different environments for enzyme (hydrophilic) and fluorescent dye (hydrophobic) components. The present invention may provide a single-step liquid emulsion deposition / integration for simplified mass-manufacture. The present invention may desire to control sensor response - dynamic range and response time via emulsion formulation. Figure 11 shows one embodiment of the present invention. A diffusion barrier 130 is provided over a glucose oxidase hydrogel layer 132 and an oxygen sensing fluorophore silicone layer 134. It should be understood that enzyme - glucose oxidase for glucose analyte may be compatible with variety of other oxidase enzymes. The present invention may also provide UV initiated polymerisable hydrogel matrix for enzyme immobilization. Figure 12 shows another portion of structure 100 according to the present invention. In one embodiment of the present invention, the fluorescent ruthenium complex dye may have the following properties: VA »3.5 μs in 02 ambient air

Polymerizable silicone-based matrix may be used for fluorescent dye immobilisation and 02 reservoir / mobility. Stability of liquid emulsion during manufacture is desirable, and it is also desirable that the emulsion be suitable for transcontinental shipping. The formulation may be varied to obtain appropriate performance - e.g. response within 10 seconds - without changing deposition / manufacturing. As seen, the present invention provides a micro-emulsion approach. In one embodiment, the initial implementation gives sub-10 second response from dry with working range compatible with blood glucose levels. It should be understood that the micro-emulsion approach offers single liquid-handling step fabrication route where complexity / performance introduced and controlled "pre" production line. The use of fluorescence lifetime (vs. intensity) measurement increases tolerance for manufacturability. The fabrication may involve liquid handling - dispensing (for inclusion in μ-devices); casting as thin-films for R&D - i.e. control of thickness; and UV-initiated polymerization. Figure 13A shows an example of thin-layer sensing material test device (slide). Figure 13B shows an optical FLT interrogation device 150 with optical performance equivalent to handheld reader. The device 150 may include a blue LED source, a mount for the test device 152, and a PIN photodiode 154. Figure 14 shows a disposable for holding a plurality of penetrating members in a disc 160 with analyte detecting members using the emulsion described herein on a layer 162. The disc 160 may include up^'to 50 or more penetrating members. The penetrating members may be bare, without molded parts. The sharpened tips are arranged to point radially outward from the center of the disc. The seal layer 164 will provide a sterility barrier. The entire disposable may be used in a hand held device which can actuate the penetrating members and also obtain a blood or fluid sample for use in analyte measurement. While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols maybe made without departing from the spirit and scope of the invention. For example, with any of the above embodiments, the analyte detecting member may be used with any of the cartridges disclosed herein or in related patent applications. The publications discussed or cited herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. All publications mentioned herein are incorporated herein by reference to disclose and describe the structures and/or methods in connection with which the publications are cited. U.S. Provisional Application Ser. No. 60/573,110 (Attorney Docket No. 38187-2732) filed: May 20, 2004 and U.S. Provisional Application Ser. No. 60/576,985 (Attorney Docket No. 38187-2732) filed June 3, 2004 are fully incorporated herein by reference for all purposes. Expected variations or differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.

Claims

WHAT IS CLAIMED IS:

1. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions.

2. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; with hydrophobic phase to hydrophilic phase volume ratios of 2:1.

3. The device of claim 2 further comprising a radial cartridge having a plurality of said analyte detecting members.

4. The device of claim 2 wherein the detecting members each include a diffusion barrier.

5. The device of claim 2 wherein the detecting members each include a glucose oxidase hydrogel layer.

6. The device of claim 2 wherein the detecting members each include an oxygen sensing fluorophore silicone layer.

7. The device of claim 2 wherein the detecting members each include an oxygen sensing fluorophore silicone layer with ruthenium.

8. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; stabilized by non-ionic surfactants as emulsifiers.

9. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; where the non-ionic surfactant has an HLB of >15

10. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; where the hydrophilic phase is cross-linked.

11. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; where the hydrophilic phase contains an enzyme or other biological entity that reacts with a target analyte and, in a reproducible way, affects a second chemical moiety that can be sensed in the hydrophobic phase.

12. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; where the sensing means is a fluorescent dye responsive to the concentration of the second chemical moiety.

13. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; where the state of the fluorescent dye can be monitored by intensity or by lifetime changes.

14. An analyte detecting member comprising: optical chemical analyte detecting members comprised of microemulsions of hydrophobic phase in hydrophilic phase; where the hydrophilic and hydrophobic phases are cross-linked by a photo- initiated crosslinker.

15. An analyte detecting member comprising: optical chemical analyte detecting members having at least one microemulsion wherein one phase as an emulsion is dispersed within another.

16. An analyte detecting member comprising: optical chemical analyte detecting members having at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received by at least one of the detecting members and drawn through a diffusion barrier into a enzyme hydrogel layer; the members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye.

17. An analyte detecting member comprising: optical chemical analyte detecting members having at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received ^!by at least one of the detecting members and drawn through a diffusion barrier into a enzyme hydrogel layer; the members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye; wherein the analyte detecting members are arranged in an array.

18. An analyte detecting member comprising: optical chemical analyte detecting members having at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received by at least one of the detecting members arid drawn through a diffusion barrier into a enzyme hydrogel layer; the members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye; wherein the analyte detecting members are arranged in an array inside a fluid pathway this is serpentine in shape.

19. An device comprising: a disc containing a plurality of penetrating members; optical chemical analyte detecting members coupled to the disc and each detecting member having at least one microemulsion wherein one phase as an emulsion is dispersed within another, wherein oxygen and glucose are received by at least one of the detecting members and drawn through a diffusion barrier into a enzyme hydrogel layer; the members are configured so that a fluorescence dye moves from a silicone layer into the hydrogel layer and oxygen is drawn into silicone layer containing the dye; wherein the analyte detecting members are arranged in an array.