Patent Publication Number: US-7717863-B2

Title: Method and apparatus for penetrating tissue

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part, and claims priority under 35 USC §120 to commonly assigned, U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002 now U.S. Pat. No 7,025,774. This application is also a continuation-in-part, and claims priority under 35 USC §120 to commonly assigned, U.S. patent application Ser. No. 10/237,261 filed Sep. 5, 2002 now U.S. Pat. No. 7,344,507. All applications listed above are fully incorporated herein by reference for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     Lancing devices are known in the medical health-care products industry for piercing the skin to produce blood for analysis. Typically, a drop of blood for this type of analysis is 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. 
     Early methods of lancing included piercing or slicing the skin with a needle or razor. Current methods utilize lancing devices that contain a multitude of spring, cam and mass actuators to drive the lancet. These include cantilever springs, diaphragms, coil springs, as well as gravity plumbs used to drive the lancet. The device may be held against the skin and mechanically triggered to ballistically launch the lancet. Unfortunately, the pain associated with each lancing event using known technology discourages patients from testing. In addition to vibratory stimulation of the skin as the driver impacts the end of a launcher stop, known spring based devices have the possibility of harmonically oscillating against the patient tissue, causing multiple strikes due to recoil. This recoil and multiple strikes of the lancet against the patient is one major impediment to patient compliance with a structured glucose monitoring regime. 
     Another impediment to patient compliance is the lack of spontaneous blood flow generated by known lancing technology. In addition to the pain as discussed above, a patient may need more than one lancing event to obtain a blood sample since spontaneous blood generation is unreliable using known lancing technology. Thus the pain is multiplied by the number of tries it takes to successfully generate spontaneous blood flow. Different skin thickness may yield different results in terms of pain perception, blood yield and success rate of obtaining blood between different users of the lancing device. Known devices poorly account for these skin thickness variations. 
     A still further impediment to improved compliance with glucose monitoring are the many steps and hassle associated with each lancing event. Many diabetic patients that are insulin dependent may need to self-test for blood glucose levels five to six times daily. The large number of steps required in traditional methods of glucose testing, ranging from lancing, to milking of blood, applying blood to the test strip, and getting the measurements from the test strip, discourages many diabetic patients from testing their blood glucose levels as often as recommended. Older patients and those with deteriorating motor skills encounter difficulty loading lancets into launcher devices, transferring blood onto a test strip, or inserting thin test strips into slots on glucose measurement meters. Additionally, the wound channel left on the patient by known systems may also be of a size that discourages those who are active with their hands or who are worried about healing of those wound channels from testing their glucose levels. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide improved tissue penetrating systems, and their methods of use. 
     Another object of the present invention is to provide tissue penetrating systems, and their methods of use, that provide reduced pain when penetrating a target tissue. 
     Yet another object of the present invention is to provide tissue penetrating systems, and their methods of use, that provide controlled depth of penetration. 
     Still a further object of the present invention is to provide tissue penetrating systems, and their methods of use, that provide controlled velocities into and out of target tissue. 
     A further object of the present invention is to provide tissue penetrating systems, and their methods of use, that provide stimulation to a target tissue. 
     Another object of the present invention is to provide tissue penetrating systems, and their methods of use, that apply a pressure to a target tissue. 
     Yet another object of the present invention is to provide tissue penetrating systems, and their methods of use, with penetrating members that remain in sterile environments prior to launch. 
     Still another object of the present invention is to provide tissue penetrating systems, and their methods of use, with penetrating members that remain in sterile environments prior to launch, and the penetrating members are not used to breach the sterile environment. 
     A further object of the present invention is to provide improved tissue penetrating systems, and their methods of use, that have user interfaces. 
     Another object of the present invention is to provide improved tissue penetrating systems, and their methods of use, that have human interfaces. 
     Yet another object of the present invention is to provide tissue penetrating systems, and their methods of use, that have low volume sample chambers. 
     Still another object of the present invention is to provide tissue penetrating systems, and their methods of use, that have sample chambers with volumes that do not exceed 1 μL. 
     Another object of the present invention is to provide tissue penetrating systems, and their methods of use, that have multiple penetrating members housed in a cartridge. 
     In one embodiment of the present invention, a tissue penetration device includes a penetrating member driver and a cartridge. A plurality of penetrating members are integrated with the cartridge. Each penetrating member is coupled to the penetrating member driver when advanced along a path into a tissue target. A penetrating member sensor is coupled to the plurality of penetrating members. The penetrating member sensor is configured to provide information relative to a depth of penetration of a penetrating member through a skin surface. 
     In another embodiment of the present invention, a tissue penetrating system includes a plurality of penetrating members coupled to a penetrating member driver. A cartridge transport device is included. A plurality of cartridges are provided, each being associated with a penetrating member. The cartridge transport device is configured to move each cartridge to a position aligning a penetrating member with the penetrating member driver to drive the penetrating member along a path into a target tissue site. 
     In another embodiment of the present invention, a tissue penetrating device includes a penetrating member. A penetrating member driver is coupled to the penetrating member. A penetrating member sensor is coupled to the penetrating member. The penetrating member sensor is configured to provide information relative to a depth of penetration of a penetrating member through a skin surface. A processor is coupled to the penetrating member sensor. The processor produces a signal indicative of a change in direction and magnitude of force exerted on the penetrating member. The processor is further configured to cause application of a braking force to the penetrating member. 
     In another embodiment of the present invention, a skin penetrating device includes a penetrating member driver. A penetrating member is coupled to the penetrating member driver. A damper is coupled to the penetrating member driver for preventing multiple oscillations of the penetrating member in the tissue target once the penetrating member has reached a desired depth. 
     In another embodiment of the present invention, a method of penetrating a target tissue advances a penetrating member through the target tissue. The penetrating member is stopped at a desired depth below a skin surface without multiple oscillations against the skin surface. The penetrating member is withdrawn from the target tissue. 
     In another embodiment of the present invention, a method of penetrating a target tissue provides a tissue penetrating system that includes a penetrating member driver, a plurality of cartridges, a plurality of penetrating members each associated with a cartridge, a plurality of sample chambers each associated with a penetrating member, and a penetrating member sensor. A penetrating member is advanced from a cartridge into the target tissue. The penetrating member is withdrawn from the target tissue. An analyte sample is received in a sample chamber. 
     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 
         FIG. 1  illustrates an embodiment of a controllable force driver in the form of a cylindrical electric penetrating member driver using a coiled solenoid-type configuration. 
         FIG. 2A  illustrates a displacement over time profile of a penetrating member driven by a harmonic spring/mass system. 
         FIG. 2B  illustrates the velocity over time profile of a penetrating member driver by a harmonic spring/mass system. 
         FIG. 2C  illustrates a displacement over time profile of an embodiment of a controllable force driver. 
         FIG. 2D  illustrates a velocity over time profile of an embodiment of a controllable force driver. 
         FIG. 3  is a diagrammatic view illustrating a controlled feed-back loop. 
         FIG. 4  is a perspective view of a tissue penetration device having features of the invention. 
         FIG. 5  is an elevation view in partial longitudinal section of the tissue penetration device of  FIG. 4 . 
         FIGS. 6A-6C  show a flowchart illustrating a penetrating member control method. 
         FIG. 7  is a diagrammatic view of a patient&#39;s finger and a penetrating member tip moving toward the skin of the finger. 
         FIG. 8  is a diagrammatic view of a patient&#39;s finger and the penetrating member tip making contact with the skin of a patient&#39;s finger. 
         FIG. 9  is a diagrammatic view of the penetrating member tip depressing the skin of a patient&#39;s finger. 
         FIG. 10  is a diagrammatic view of the penetrating member tip further depressing the skin of a patient&#39;s finger. 
         FIG. 11  is a diagrammatic view of the penetrating member tip penetrating the skin of a patient&#39;s finger. 
         FIG. 12  is a diagrammatic view of the penetrating member tip penetrating the skin of a patient&#39;s finger to a desired depth. 
         FIG. 13  is a diagrammatic view of the penetrating member tip withdrawing from the skin of a patient&#39;s finger. 
         FIGS. 14-18  illustrate a method of tissue penetration that may measure elastic recoil of the skin. 
         FIG. 19  is a perspective view in partial section of a tissue penetration sampling device with a cartridge of sampling modules. 
         FIG. 20  is a perspective view of a sampling module cartridge with the sampling modules arranged in a ring configuration. 
         FIG. 21  illustrate an embodiment of a cartridge for use in sampling having a sampling cartridge body and a penetrating member cartridge body. 
         FIG. 22A  shows a device for use on a tissue site having a plurality of penetrating members. 
         FIG. 22B  shows rear view of a device for use on a tissue site having a plurality of penetrating members. 
         FIG. 22C  shows a schematic of a device for use on a tissue site with a feedback loop and optionally a damper. 
         FIG. 23A  shows an embodiment of a device with a user interface. 
         FIG. 23B  shows an outer view of a device with a user interface. 
         FIG. 24  is a cut away view of a system for sampling body fluid. 
         FIG. 25  is an exploded view of a cartridge for use with a system for sampling body fluid. 
         FIG. 26  is an exploded view of a cartridge having multiple penetrating members for use with a system for sampling body fluid. 
         FIGS. 27-28  show cartridges for use with a system for sampling body fluid. 
         FIG. 29  shows a cutaway view of another embodiment of a system for sampling body fluid. 
         FIG. 30  shows the density associated with a cartridge according to the present invention. 
         FIG. 31  shows a cutaway view of another embodiment of a system for sampling body fluid. 
         FIG. 32  is a cut away view of a cartridge according to the present invention. 
         FIGS. 33-34  show views of a body sampling system using multiple cartridges. 
         FIG. 35  shows an embodiment of the present invention with a tissue stabilizing member. 
         FIG. 36  shows a cartridge according to the present invention with a tissue stabilizing member. 
         FIG. 37  shows a system according to the present invention with a moveable cartridge. 
     
    
    
     DESCRIPTION OF THE SPECIFIC EMBODIMENTS 
     The present invention provides a solution for body fluid sampling. Specifically, some embodiments of the present invention provides a penetrating member device for consistently creating a wound with spontaneous body fluid flow from a patient. The invention may be a multiple penetrating member device with an optional high density design. It may use penetrating members of smaller size than known penetrating members. The device may be used for multiple lancing events without having to remove a disposable from the device or for the user to handle sharps. The invention may provide improved sensing capabilities. At least some of these and other objectives described herein will be met by embodiments of the present invention. 
     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 should 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. 
     “Analyte detecting member” refers to any use, singly or in combination, of chemical test reagents and methods, electrical test circuits and methods, physical test components and methods, optical test components and methods, and biological test reagents and methods to yield information about a blood sample. Such methods are well known in the art and may be based on teachings of, e.g. Tietz Textbook of Clinical Chemistry, 3d Ed., Sec. V, pp. 776-78 (Burtis &amp; Ashwood, Eds., W.B. Saunders Company, Philadelphia, 1999); U.S. Pat. No. 5,997,817 to Chrismore et al. (Dec. 7, 1999); U.S. Pat. No. 5,059,394 to Phillips et al. (Oct. 22, 1991); U.S. Pat. No. 5,001,054 to Wagner et al. (Mar. 19, 1991); and U.S. Pat. No. 4,392,933 to Nakamura et al. (Jul. 12, 1983), the teachings of which are hereby incorporated by reference, as well as others. Analyte detecting member may include tests in the sample test chamber that test electrochemical properties of the blood, or they may include optical means for sensing optical properties of the blood (e.g. oxygen saturation level), or they may include biochemical reagents (e.g. antibodies) to sense properties (e.g. presence of antigens) of the blood. The analyte detecting member may comprise biosensing or reagent material that will react with an analyte in blood (e.g. glucose) or other body fluid so that an appropriate signal correlating with the presence of the analyte is generated and can be read by the reader apparatus. By way of example and not limitation, analyte detecting member may “associated with”, “mounted within”, or “coupled to” a chamber or other structure when the analyte detecting member participates in the function of providing an appropriate signal about the blood sample to the reader device. Analyte detecting member may also include nanowire analyte detecting members as described herein. Analyte detecting member may use potentiometric, coulometric, or other method useful for detection of analyte levels. 
     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  FIG. 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 may be used, for example, 4, 5, 6, 7 or more coils may be used. 
     Referring to the embodiment of  FIG. 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  FIGS. 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 deformation 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  FIG. 2C  which illustrates an embodiment of a controlled displacement profile and  FIG. 2D  which illustrates an embodiment of a the controlled velocity profile. These are compared to  FIGS. 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, filed Apr. 19, 2002 and previously incorporated herein. 
       FIG. 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, filed Apr. 19, 2002 and previously incorporated herein. The processor  60  calculates the movement of the penetrating member by comparing the  20  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&#39;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 lancet, both diameter and lancet 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 user 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. 
       FIG. 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  FIG. 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&#39;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 . 
     The driver coil pack  88 , position sensor  91  and coupler shaft guide  111  are all secured to a base  113 . The base  113  is longitudinally coextensive with the driver coil pack  88 , position sensor  91  and coupler shaft guide  111 . The base  113  can take the form of a rectangular piece of metal or polymer, or may be a more elaborate housing with recesses, which are configured to accept the various components of the lancing device  80 . 
     As discussed above, the magnetic member  102  is configured to slide within an axial lumen  105  of the driver coil pack  88 . The driver coil pack  88  includes a most distal first coil  114 , a second coil  115 , which is axially disposed between the first coil  114  and a third coil  116 , and a proximal-most fourth coil  117 . Each of the first coil  114 , second coil  115 , third coil  116  and fourth coil  117  has an axial lumen. The axial lumens of the first through fourth coils are configured to be coaxial with the axial lumens of the other coils and together form the axial lumen  105  of the driver coil pack  88  as a whole. Axially adjacent each of the coils  114 - 117  is a magnetic disk or washer  118  that augments completion of the magnetic circuit of the coils  114 - 117  during a lancing cycle of the device  80 . The magnetic washers  118  of the embodiment of  FIG. 5  are made of ferrous steel but could be made of any other suitable magnetic material, such as iron or ferrite. The outer shell  89  of the driver coil pack  88  is also made of iron or steel to complete the magnetic path around the coils and between the washers  118 . The magnetic washers  118  have an outer diameter commensurate with an outer diameter of the driver coil pack  88  of about 4.0 to about 8.0 mm. The magnetic washers  118  have an axial thickness of about 0.05, to about 0.4 mm, specifically, about 0.15 to about 0.25 mm. 
     Wrapping or winding an elongate electrical conductor  121  about an axial lumen until a sufficient number of windings have been achieved forms the coils  114 - 117 . The elongate electrical conductor  121  is generally an insulated solid copper wire with a small outer transverse dimension of about 0.06 mm to about 0.88 mm, specifically, about 0.3 mm to about 0.5 mm. In one embodiment, 32 gauge copper wire is used for the coils  114 - 117 . The number of windings for each of the coils  114 - 117  of the driver pack  88  may vary with the size of the coil, but for some embodiments each coil  114 - 117  may have about 30 to about 80 turns, specifically, about 50 to about 60 turns. Each coil  114 - 117  can have an axial length of about 1.0 to about 3.0 mm, specifically, about 1.8 to about 2.0 mm. Each coil  114 - 117  can have an outer transverse dimension or diameter of about 4.0, to about 2.0 mm, specifically, about 9.0 to about 12.0 mm. The axial lumen  105  can have a transverse dimension of about 1.0 to about 3.0 mm. 
     It may be advantageous in some driver coil  88  embodiments to replace one or more of the coils with permanent magnets, which produce a magnetic field similar to that of the coils when the coils are activated. In particular, it may be desirable in some embodiments to replace the second coil  115 , the third coil  116  or both with permanent magnets. In addition, it may be advantageous to position a permanent magnet at or near the proximal end of the coil driver pack in order to provide fixed magnet zeroing function for the magnetic member (Adams magnetic Products 23A0002 flexible magnet material (800) 747-7543). 
     A permanent bar magnet  119  is disposed on the proximal end of the driver coil pack  88 . As shown in  FIG. 5 , the bar magnet  119  is arranged so as to have one end disposed adjacent the travel path of the magnetic member  102  and has a polarity configured so as to attract the magnetic member  102  in a centered position with respect to the bar magnet  119 . Note that the polymer guide tube  105 ′ can be configured to extend proximally to insulate the inward radial surface of the bar magnet  119  from an outer surface of the magnetic member  102 . This arrangement allows the magnetic member  119  and thus the elongate coupler shaft  84  to be attracted to and held in a zero point or rest position without the consumption of electrical energy from the power supply  125 . 
     Having a fixed zero or start point for the elongate coupler shaft  84  and penetrating member  83  may be useful to properly controlling the depth of penetration of the penetrating member  83  as well as other lancing parameters. This can be because some methods of depth penetration control for a controllable driver measure the acceleration and displacement of the elongate coupler shaft  84  and penetrating member  83  from a known start position. If the distance of the penetrating member tip  96  from the target tissue is known, acceleration and displacement of the penetrating member is known and the start position of the penetrating member is know, the time and position of tissue contact and depth of penetration can be determined by the processor  93 . 
     Any number of configurations for a magnetic bar  119  can be used for the purposes discussed above. In particular, a second permanent bar magnet (not shown) could be added to the proximal end of the driver coil pack  88  with the magnetic fields of the two bar magnets configured to complement each other. In addition, a disc magnet could be used as illustrated in  FIG. 23(   a ). The disc magnet is shown disposed at the proximal end of the driver coiled pack  88  with a polymer non-magnetic disc disposed between the proximal-most coil  117  and disc magnet and positions disc magnet away from the proximal end of the proximal-most coil  117 . The polymer non-magnetic disc spacer is used so that the magnetic member  102  can be centered in a zero or start position slightly proximal of the proximal-most coil  117  of the driver coil pack  88 . This allows the magnetic member to be attracted by the proximal-most coil  117  at the initiation of the lancing cycle instead of being passive in the forward drive portion of the lancing cycle. 
     An inner lumen of the polymer non-magnetic disc can be configured to allow the magnetic member  102  to pass axially there through while an inner lumen of the disc magnet can be configured to allow the elongate coupler shaft  84  to pass through but not large enough for the magnetic member  102  to pass through. This results in the magnetic member  102  being attracted to the disc magnet and coming to rest with the proximal surface of the magnetic member  102  against a distal surface of the disc magnet. This arrangement provides for a positive and repeatable stop for the magnetic member, and hence the penetrating member. 
     Typically, when the electrical current in the coils  114 - 117  of the driver coil pack  88  is off, a magnetic member  102  made of soft iron is attracted to the bar magnet  119  or disc magnet. The magnetic field of the driver coil pack  88  and the bar magnet  119  or disc magnet, or any other suitable magnet, can be configured such that when the electrical current in the coils  114 - 117  is turned on, the leakage magnetic field from the coils  114 - 117  has the same polarity as the bar magnet  119  or disc magnet. This results in a magnetic force that repels the magnetic member  102  from the bar magnet  119  or disc magnet and attracts the magnetic member  102  to the activated coils  114 - 117 . For this configuration, the bar magnet  119  or disc magnet thus act to facilitate acceleration of the magnetic member  102  as opposed to working against the acceleration. 
     Electrical conductors  122  couple the driver coil pack  88  with the processor  93  which can be configured or programmed to control the current flow in the coils  114 - 117  of the driver coil pack  88  based on position feedback from the position sensor  91 , which is coupled to the processor  93  by electrical conductors  94 . A power source  125  is electrically coupled to the processor  93  and provides electrical power to operate the processor  93  and power the coil driver pack  88 . The power source  125  may be one or more batteries that provide direct current power to the  93  processor. 
     Referring to  FIGS. 29A-29C , a flow diagram is shown that describes the operations performed by the processor  93  in controlling the penetrating member  83  of the lancing device  80  discussed above during an operating cycle.  FIGS. 30-36  illustrate the interaction of the penetrating member  83  and skin  133  of the patient&#39;s finger  134  during an operation cycle of the penetrating member device  83 . The processor  93  operates under control of programming steps that are stored in an associated memory. When the programming steps are executed, the processor  93  performs operations as described herein. Thus, the programming steps implement the functionality of the operations described with respect to the flow, diagram of  FIG. 29 . The processor  93  can receive the programming steps from a program product stored in recordable media, including a direct access program product storage device such as a hard drive or flash ROM, a removable program product storage device such as a floppy disk, or in any other manner known to those of skill in the art. The processor  93  can also download the programming steps through a network connection or serial connection. 
     In the first operation, represented by the flow diagram box numbered  245  in  FIG. 6A , the processor  93  initializes values that it stores in memory relating to control of the penetrating member, such as variables that it uses to keep track of the controllable driver  179  during movement. For example, the processor may set a clock value to zero and a penetrating member position value to zero or to some other initial value. The processor  93  may also cause power to be removed from the coil pack  88  for a period of time, such as for about 10 ms, to allow any residual flux to dissipate from the coils. 
     In the initialization operation, the processor  93  also causes the penetrating member to assume an initial stationary position. When in the initial stationary position, the penetrating member  83  is typically fully retracted such that the magnetic member  102  is positioned substantially adjacent the fourth coil  117  of the driver coil pack  88 , shown in  FIG. 5  above. The processor  93  can move the penetrating member  83  to the initial stationary position by pulsing an electrical current to the fourth coil  117  to thereby attract the magnetic member  102  on the penetrating member  83  to the fourth coil  117 . Alternatively, the magnetic member can be positioned in the initial stationary position by virtue of a permanent magnet, such as the bar magnet, disc magnet or any other suitable magnet as discussed above with regard to the tissue penetration device illustrated in  FIGS. 20 and 21 . 
     In the next operation, represented by the flow diagram box numbered  247 , the processor  93  energizes one or more of the coils in the coil pack  88 . This should cause the penetrating member  83  to begin to move (i.e., achieve a non-zero speed) toward the skin target  133 . The processor  93  then determines whether or not the penetrating member is indeed moving. The processor  93  can determine whether the penetrating member  83  is moving by monitoring the position of the penetrating member  83  to determine whether the position changes over time. The processor  93  can monitor the position of the penetrating member  83  by keeping track of the position of the optical encoder flag  106  secured to the elongate coupler shaft  84  wherein the encoder  91  produces a signal coupled to the processor  93  that indicates the spatial position of the penetrating member  83 . 
     If the processor  93  determines (via timeout without motion events) that the penetrating member  83  is not moving then the process proceeds to where the processor deems that an error condition is present. This means that some error in the system is causing the penetrating member  83  not to move. The error may be mechanical, electrical, or software related. For example, the penetrating member  83  may be stuck in the stationary position because something is impeding its movement. 
     If the processor  93  determines that the penetrating member  83  is indeed moving (a “Yes” result from the decision box numbered  249 ), then the process proceeds to the operation represented by the flow diagram box numbered  257 . In this operation, the processor  93  causes the penetrating member  83  to continue to accelerate and launch toward the skin target  133 , as indicated by the arrow  135  in  FIG. 7 . The processor  93  can achieve acceleration of the penetrating member  83  by sending an electrical current to an appropriate coil  114 - 117  such that the coil  114 - 117  exerts an attractive magnetic launching force on the magnetic member  102  and causes the magnetic member  102  and the penetrating member  83  coupled thereto to move in a desired direction. For example, the processor  93  can cause an electrical current to be sent to the third coil.  116  so that the third coil  116  attracts the magnetic member  102  and causes the magnetic member  102  to move from a position adjacent the fourth coil  117  toward the third coil  116 . The processor preferably determines which coil  114 - 117  should be used to attract the magnetic member  102  based on the position of the magnetic member  102  relative to the coils  114 - 117 . In this manner, the processor  93  provides a controlled force to the penetrating member that controls the movement of the penetrating member. 
     During this operation, the processor  93  periodically or continually monitors the position and/or velocity of the penetrating member  83 . In keeping track of the velocity and position of the penetrating member  83  as the penetrating member  83  moves towards the patient&#39;s skin  133  or other tissue, the processor  93  also monitors and adjusts the electrical current to the coils  114 - 117 . In some embodiments, the processor  93  applies current to an appropriate coil  114 - 117  such that the penetrating member  83  continues to move according to a desired direction and acceleration. In the instant case, the processor  93  applies current to the appropriate coil  114 - 117  that will cause the penetrating member  83  to continue to move in the direction of the patient&#39;s skin  133  or other tissue to be penetrated. 
     The processor  93  may successively transition the current between coils  114 - 117  so that as the magnetic member  102  moves past a particular coil  114 - 117 , the processor  93  then shuts off current to that coil  114 - 117  and then applies current to another coil  114 - 117  that will attract the magnetic member  102  and cause the magnetic member  102  to continue to move in the desired direction. In transitioning current between the coils  114 - 117 , the processor  93  can take into account various factors, including the speed of the penetrating member  83 , the position of the penetrating member  83  relative to the coils  114 - 117 , the number of coils  114 - 117 , and the level of current to be applied to the coils  114 - 117  to achieve a desired speed or acceleration. 
     In the next operation, the processor  93  determines whether the cutting or distal end tip  96  of the penetrating member  83  has contacted the patient&#39;s skin  133 , as shown in  FIG. 8  and as represented by the decision box numbered  165  in  FIG. 6B . The processor  93  may determine whether the penetrating member  83  has made contact with the target tissue  133  by a variety of methods, including some that rely on parameters which are measured prior to initiation of a lancing cycle and other methods that are adaptable to use during a lancing cycle without any predetermined parameters. 
     In one embodiment, the processor  93  determines that the skin has been contacted when the end tip  96  of the penetrating member  83  has moved a predetermined distance with respect to its initial position. If the distance from the tip  261  of the penetrating member  83  to the target tissue  133  is known prior to initiation of penetrating member  83  movement, the initial position of the penetrating member  83  is fixed and known, and the movement and position of the penetrating member  83  can be accurately measured during a lancing cycle, then the position and time of penetrating member contact can be determined. 
     This method requires an accurate measurement of the distance between the penetrating member tip  96  and the patient&#39;s skin  133  when the penetrating member  83  is in the zero time or initial position. This can be accomplished in a number of ways. One way is to control all of the mechanical parameters that influence the distance from the penetrating member tip  96  to the patient&#39;s tissue or a surface of the lancing device  80  that will contact the patient&#39;s skin  133 . This could include the start position of the magnetic member  102 , magnetic path tolerance, magnetic member  102  dimensions, driver coil pack  88  location within the lancing device  80  as a whole, length of the elongate coupling shaft  84 , placement of the magnetic member  102  on the elongate coupling shaft  84 , length of the penetrating member  83  etc. 
     If all these parameters, as well as others can be suitably controlled in manufacturing with a tolerance stack-up that is acceptable, then the distance from the penetrating member tip  96  to the target tissue  133  can be determined at the time of manufacture of the lancing device  80 . The distance could then be programmed into the memory of the processor  93 . If an adjustable feature is added to the lancing device  80 , such as an adjustable length elongate coupling shaft  84 , this can accommodate variations in all of the parameters noted above, except length of the penetrating member  83 . An electronic alternative to this mechanical approach would be to calibrate a stored memory contact point into the memory of the processor  93  during manufacture based on the mechanical parameters described above. 
     In another embodiment, moving the penetrating member tip  96  to the target tissue  133  very slowly and gently touching the skin  133  prior to actuation can accomplish the distance from the penetrating member tip  96  to the tissue  133 . The position sensor can accurately measure the distance from the initialization point to the point of contact, where the resistance to advancement of the penetrating member  83  stops the penetrating member movement. The penetrating member  83  is then retracted to the initialization point having measured the distance to the target tissue  133  without creating any discomfort to the user. 
     In another embodiment, the processor  93  may use software to determine whether the penetrating member  83  has made contact with the patient&#39;s skin  133  by measuring for a sudden reduction in velocity of the penetrating member  83  due to friction or resistance imposed on the penetrating member  83  by the patient&#39;s skin  133 . The optical encoder  91  measures displacement of the penetrating member  83 . The position output data provides input to the interrupt input of the processor  93 . The processor  93  also has a timer capable of measuring the time between interrupts. The distance between interrupts is known for the optical encoder  91 , so the velocity of the penetrating member  83  can be calculated by dividing the distance between interrupts by the time between the interrupts. 
     This method requires that velocity losses to the penetrating member  83  and elongate coupler  84  assembly due to friction are known to an acceptable level so that these velocity losses and resulting deceleration can be accounted for when establishing a deceleration threshold above which contact between penetrating member tip  96  and target tissue  133  will be presumed. This same concept can be implemented in many ways. For example, rather than monitoring the velocity of the penetrating member  83 , if the processor  93  is controlling the penetrating member driver in order to maintain a fixed velocity, the power, to the driver  88  could be monitored. If an amount of power above a predetermined threshold is required in order to maintain a constant velocity, then contact between the tip of the penetrating member  96  and the skin  133  could be presumed. 
     In yet another embodiment, the processor  93  determines skin  133  contact by the penetrating member  83  by detection of an acoustic signal produced by the tip  96  of the penetrating member  83  as it strikes the patient&#39;s skin  133 . Detection of the acoustic signal can be measured by an acoustic detector  136  placed in contact with the patient&#39;s skin  133  adjacent a penetrating member penetration site  137 , as shown in  FIG. 8 . Suitable acoustic detectors  136  include piezo electric transducers, microphones and the like. The acoustic detector  136  transmits an electrical signal generated by the acoustic signal to the processor  93  via electrical conductors  138 . In another embodiment, contact of the penetrating member  83  with the patient&#39;s skin  133  can be determined by measurement of electrical continuity in a circuit that includes the penetrating member  83 , the patient&#39;s finger  134  and an electrical contact pad  240  that is disposed on the patient&#39;s skin  133  adjacent the contact site  137  of the penetrating member  83 , as shown in  FIG. 8 . In this embodiment, as soon as the penetrating member  83  contacts the patient&#39;s skin  133 , the circuit  139  is completed and current flows through the circuit  139 . Completion of the circuit  139  can then be detected by the processor  93  to confirm skin  133  contact by the penetrating member  83 . 
     If the penetrating member  83  has not contacted the target skin  133 , then the process proceeds to a timeout operation, in  FIG. 6B . In the timeout operation, the processor  93  waits a predetermined time period. If the timeout period has not yet elapsed, then the processor continues to monitor whether the penetrating member has contacted the target skin  133 . The processor  93  preferably continues to monitor the position and speed of the penetrating member  83 , as well as the electrical current to the appropriate coil  114 - 117  to maintain the desired penetrating member  83  movement. 
     If the timeout period elapses without the penetrating member  83  contacting the skin then it is deemed that the penetrating member  83  will not contact the skin and the process proceeds to a withdraw phase, where the penetrating member is withdrawn away from the skin  133 , as discussed more fully below. The penetrating member  83  may not have contacted the target skin  133  for a variety of reasons, such as if the patient removed the skin  133  from the lancing device or if something obstructed the penetrating member  83  prior to it contacting the skin. 
     The processor  93  may also proceed to the withdraw phase prior to skin contact for other reasons. For example, at some point after initiation of movement of the penetrating member  83 , the processor  93  may determine that the forward acceleration of the penetrating member  83  towards the patient&#39;s skin  133  should be stopped or that current to all coils  114 - 117  should be shut down. This can occur, for example, if it is determined that the penetrating member  83  has achieved sufficient forward velocity, but has not yet contacted the skin  133 . In one embodiment, the average penetration velocity of the penetrating member  83  from the point of contact with the skin to the point of maximum penetration may be about 2.0 to about 10.0 m/s, specifically, about 3.8 to about 4.2 m/s. In another embodiment, the average penetration velocity of the penetrating member may be from about 2 to about 8 meters per second, specifically, about 2 to about 4 m/s. 
     The processor  93  can also proceed to the withdraw phase if it is determined that the penetrating member  83  has fully extended to the end of the power stroke of the operation cycle of lancing procedure. In other words, the process may proceed to withdraw phase when an axial center  141  of the magnetic member  102  has moved distal of an axial center  142  of the first coil  114  as show in  FIG. 5 . In this situation, any continued power to any of the coils  114 - 117  of the driver coil pack  88  serves to decelerate the magnetic member  102  and thus the penetrating member  83 . In this regard, the processor  93  considers the length of the penetrating member  83  (which can be stored in memory) the position of the penetrating member  83  relative to the magnetic member  102 , as well as the distance that the penetrating member  83  has traveled. 
     With reference again to  FIG. 6B , if the processor  93  determines that the penetrating member  83  has contacted the skin  133  (a “Yes” outcome from the decision box  165 ), then the processor  93  can adjust the speed of the penetrating member  83  or the power delivered to the penetrating member  83  for skin penetration to overcome any frictional forces on the penetrating member  83  in order to maintain a desired penetration velocity of the penetrating member. 
     As the velocity of the penetrating member  83  is maintained after contact with the skin  133 , the distal tip  96  of the penetrating member  83  will first begin to depress or tent the contacted skin  137  and the skin  133  adjacent the penetrating member  83  to form a tented portion  243  as shown in  FIG. 9  and further shown in  FIG. 10 . As the penetrating member  83  continues to move in a distal direction or be driven in a distal direction against the patient&#39;s skin  133 , the penetrating member  83  will eventually begin to penetrate the skin  133 , as shown in  FIG. 11 . Once penetration of the skin  133  begins, the static force at the distal tip  96  of the penetrating member  83  from the skin  133  will become a dynamic cutting force, which is generally less than the static tip force. As a result in the reduction of force on the distal tip  96  of the penetrating member  83  upon initiation of cutting, the tented portion  243  of the skin  133  adjacent the distal tip  96  of the penetrating member  83  which had been depressed as shown in  FIGS. 32 and 24  will spring back as shown in  FIG. 11 . 
     In the next operation, represented by the decision box numbered  171  in  FIG. 6B , the processor  93  determines whether the distal end  96  of the penetrating member  83  has reached a brake depth. The brake depth is the skin penetration depth for which the processor  93  determines that deceleration of the penetrating member  83  is to be initiated in order to achieve a desired final penetration depth  144  of the penetrating member  83  as show in  FIG. 12 . The brake depth may be pre-determined and programmed into the processor&#39;s memory, or the processor  93  may dynamically determine the brake depth during the actuation. The amount of penetration of the penetrating member  83  in the skin  133  of the patient may be measured during the operation cycle of the penetrating member device  80 . In addition, as discussed above, the penetration depth suitable for successfully obtaining a useable sample can depend on the amount of tenting of the skin  133  during the lancing cycle. The amount of tenting of the patient&#39;s skin  133  can in turn depend on the tissue characteristics of the patient such as elasticity, hydration etc. A method for determining these characteristics is discussed below with regard to skin  133  tenting measurements during the lancing cycle and illustrated in  FIGS. 37-41 . 
     Penetration measurement can be carried out by a variety of methods that are not dependent on measurement of tenting of the patient&#39;s skin. In one embodiment, the penetration depth of the penetrating member  83  in the patient&#39;s skin  133  is measured by monitoring the amount of capacitance between the penetrating member  83  and the patient&#39;s skin  133 . In this embodiment, a circuit includes the penetrating member  83 , the patient&#39;s finger  134 , the processor  93  and electrical conductors connecting these elements. As the penetrating member  83  penetrates the patient&#39;s skin  133 , the greater the amount of penetration, the greater the surface contact area between the penetrating member  83  and the patient&#39;s skin  133 . As the contact area increases, so does the capacitance between the skin  133  and the penetrating member  83 . The increased capacitance can be easily measured by the processor  93  using methods known in the art and penetration depth can then be correlated to the amount of capacitance. The same method can be used by measuring the electrical resistance between the penetrating member  83  and the patient&#39;s skin. 
     If the brake depth has not yet been reached, then a “No” results from the decision box  171  and the process proceeds to the timeout operation represented by the flow diagram box numbered  173 . In the timeout operation, the processor  93  waits a predetermined time period. If the timeout period has not yet elapsed (a “No” outcome from the decision box  173 ), then the processor continues to monitor whether the brake depth has been reached. If the timeout period elapses without the penetrating member  83  achieving the brake depth (a “Yes” output from the decision box. 173 ), then the processor  93  deems that the penetrating member  83  will not reach the brake depth and the process proceeds to the withdraw phase, which is discussed more fully below. This may occur, for example, if the penetrating member  83  is stuck at a certain depth. 
     With reference again to the decision box numbered  171  in  FIG. 6B , if the penetrating member does reach the brake depth (a “Yes” result), then the process proceeds to the operation represented by the flow diagram box numbered  275 . In this operation, the processor  93  causes a braking force to be applied to the penetrating member to thereby reduce the speed of the penetrating member  83  to achieve a desired amount of final skin penetration depth  144 , as shown in  FIG. 26 . Note that  FIGS. 32 and 33  illustrate the penetrating member making contact with the patient&#39;s skin and deforming or depressing the skin prior to any substantial penetration of the skin. The speed of the penetrating member  83  is preferably reduced to a value below a desired threshold and is ultimately reduced to zero. The processor  93  can reduce the speed of the penetrating member  83  by causing a current to be sent to a  114 - 117  coil that will exert an attractive braking force on the magnetic member  102  in a proximal direction away from the patient&#39;s tissue or skin  133 , as indicated by the arrow  190  in  FIG. 13 . Such a negative force reduces the forward or distally oriented speed of the penetrating member  83 . The processor  93  can determine which coil  114 - 117  to energize based upon the position of the magnetic member  102  with respect to the coils  114 - 117  of the driver coil pack  88 , as indicated by the position sensor  91 . 
     In the next operation, the process proceeds to the withdraw phase, as represented by the flow diagram box numbered  177 . The withdraw phase begins with the operation represented by the flow diagram box numbered  178  in  FIG. 6C . Here, the processor  93  allows the penetrating member  83  to settle at a position of maximum skin penetration  144 , as shown in  FIG. 12 . In this regard, the processor  93  waits until any motion in the penetrating member  83  (due to vibration from impact and spring energy stored in the skin, etc.) has stopped by monitoring changes in position of the penetrating member  83 . The processor  93  preferably waits until several milliseconds (ms), such as on the order of about 8 ms, have passed with no changes in position of the penetrating member  83 . This is an indication that movement of the penetrating member  83  has ceased entirely. In some embodiments, the penetrating member may be allowed to settle for about 1 to about 2000 milliseconds, specifically, about 50 to about 200 milliseconds. For other embodiments, the settling time may be about 1 to about 200 milliseconds. 
     It is at this stage of the lancing cycle that a software method can be used to measure the amount of tenting of the patient&#39;s skin  133  and thus determine the skin  133  characteristics such as elasticity, hydration and others. Referring to  FIGS. 37-41 , a penetrating member  83  is illustrated in various phases of a lancing cycle with target tissue  133 .  FIG. 14  shows tip  96  of penetrating member  83  making initial contact with the skin  133  at the point of initial impact. 
       FIG. 15  illustrates an enlarged view of the penetrating member  83  making initial contact with the tissue  133  shown in  FIG. 14 . In  FIG. 16 , the penetrating member tip  96  has depressed or tented the skin  133  prior to penetration over a distance of X, as indicated by the arrow labeled X in  FIG. 16 . In  FIG. 17 , the penetrating member  83  has reached the full length of the cutting power stroke and is at maximum displacement. In this position, the penetrating member tip  96  has penetrated the tissue  133  a distance of Y, as indicated by the arrow labeled Y in  FIG. 16 . As can be seen from comparing  FIG. 15  with  FIG. 17 , the penetrating member tip  96  was displaced a total distance of X plus Y from the time initial contact with the skin  133  was made to the time the penetrating member tip  96  reached its maximum extension as shown in  FIG. 17 . However, the penetrating member tip  96  has only penetrated the skin  133  a distance Y because of the tenting phenomenon. 
     At the end of the power stroke of the penetrating member  83 , as discussed above with regard to box  179  of  FIG. 6C , the processor  93  allows the penetrating member to settle for about 8 msec. It is during this settling time that the skin  133  rebounds or relaxes back to approximately its original configuration prior to contact by the penetrating member  83  as shown in  FIG. 18 . The penetrating member tip  96  is still buried in the skin to a depth of Y, as shown in  FIG. 18 , however the elastic recoil of the tissue has displaced the penetrating member rearward or retrograde to the point of inelastic tenting that is indicated by the arrows Z in  FIG. 18 . During the rearward displacement of the penetrating member  83  due to the elastic tenting of the tissue  133 , the processor reads and stores the position data generated by the position sensor  91  and thus measures the amount of elastic tenting, which is the difference between X and Z. 
     Referring to  FIG. 19 , a tissue penetration sampling device  80  is shown with the controllable driver  179  of  FIG. 4  coupled to a sampling module cartridge  205  and disposed within a driver housing  206 . A ratchet drive mechanism  207  is secured to the driver housing  206 , coupled to the sampling module cartridge  205  and configured to advance a sampling module belt  208  within the sampling module cartridge  205  so as to allow sequential use of each sampling module  209  in the sampling module belt  208 . The ratchet drive mechanism  207  has a drive wheel  211  configured to engage the sampling modules  209  of the sampling module belt  208 . The drive wheel  211  is coupled to an actuation lever  212  that advances the drive wheel  211  in increments of the width of a single sampling module  209 . A T-slot drive coupler  213  is secured to the elongated coupler shaft  84 . 
     A sampling module  209  is loaded and ready for use with the drive head  98  of the penetrating member  83  of the sampling module  209  loaded in the T-slot  214  of the drive coupler  213 . A sampling site  215  is disposed at the distal end  216  of the sampling module  209  disposed about a penetrating member exit port  217 . The distal end  216  of the sampling module  209  is exposed in a module window  218 , which is an opening in a cartridge cover  221  of the sampling module cartridge  205 . This allows the distal end  216  of the sampling module  209  loaded for use to be exposed to avoid contamination of the cartridge cover  221  with blood from the lancing process. 
     A reader module  222  is disposed over a distal portion of the sampling module  209  that is loaded in the drive coupler  213  for use and has two contact brushes  224  that are configured to align and make electrical contact with analyte detecting member contacts  225  of the sampling module  209  as shown in  FIG. 77 . With electrical contact between the analyte detecting member contacts  225  and contact brushes  224 , the processor  93  of the controllable driver  179  can read a signal from an analytical region  226  of the sampling module  209  after a lancing cycle is complete and a blood sample enters the analytical region  226  of the sampling module  209 . The contact brushes  224  can have any suitable configuration that will allow the sampling module belt  208  to pass laterally beneath the contact brushes  224  and reliably make electrical contact with the sampling module  209  loaded in the drive coupler  213  and ready for use. A spring loaded conductive ball bearing is one example of a contact brush  224  that could be used. A resilient conductive strip shaped to press against the inside surface of the flexible polymer sheet  227  along the analyte detecting member region  228  of the sampling module  209  is another embodiment of a contact brush  224 . 
     The sampling module cartridge  205  has a supply canister  229  and a receptacle canister  230 . The unused sampling modules of the sampling module belt  208  are disposed within the supply canister  229  and the sampling modules of the sampling module belt  208  that have been used are advanced serially after use into the receptacle canister  230 . 
       FIG. 20  illustrates a further embodiment of sampling module cartridges.  FIG. 20  shows a sampling module cartridge  202  in a carousel configuration with adjacent sampling modules  204  connected rigidly and with analyte detecting members  206  from the analytical regions of the various sampling modules  204  disposed near an inner radius  208  of the carousel. The sampling modules  204  of the sampling module cartridge  202  are advanced through a drive coupler  213  but in a circular as opposed to a linear fashion. 
       FIG. 21  shows an exploded view in perspective of the cartridge  245 , which has a proximal end portion  254  and a distal end portion  255 . The penetrating member cartridge body  246  is disposed at the proximal end portion  254  of the cartridge  245  and has a plurality of penetrating member module portions  250 , such as the penetrating member module portion  250 . Each penetrating member module portion  250  has a penetrating member channel  251  with a penetrating member  83  slidably disposed within the penetrating member channel  251 . The penetrating member channels  251  are substantially parallel to the longitudinal axis  252  of the penetrating member cartridge body  246 . The penetrating members  83  shown have a drive head  98 , shaft portion  201  and sharpened tip  96 . The drive head  98  of the penetrating members are configured to couple to a drive coupler (not shown), such as the drive coupler  85  discussed above. 
     The penetrating members  83  are free to slide in the respective penetrating member channels  251  and are nominally disposed with the sharpened tip  96  withdrawn into the penetrating member channel  251  to protect the tip  96  and allow relative rotational motion between the penetrating member cartridge body  246  and the sampling cartridge body  247  as shown by arrow  256  and arrow  257  in  FIG. 21 . The radial center of each penetrating member channel  251  is disposed a fixed, known radial distance from the longitudinal axis  252  of the penetrating member cartridge body  246  and a longitudinal axis  258  of the cartridge  245 . By disposing each penetrating member channel  251  a fixed known radial distance from the longitudinal axes  252  and  258  of the penetrating member cartridge body  246  and cartridge  245 , the penetrating member channels  251  can then be readily and repeatably aligned in a functional arrangement with penetrating member channels  253  of the sampling cartridge body  247 . The penetrating member cartridge body  246  rotates about a removable pivot shaft  259  which has a longitudinal axis  260  that is coaxial with the longitudinal axes  252  and  250  of the penetrating member cartridge body  246  and cartridge  245 . 
     The sampling cartridge body  247  is disposed at the distal end portion  255  of the cartridge and has a plurality of sampling module portions  248  disposed radially about the longitudinal axis  249  of the sampling cartridge body  247 . The longitudinal axis  249  of the sampling cartridge body  247  is coaxial with the longitudinal axes  252 ,  258  and  260  of the penetrating member cartridge body  246 , cartridge  245  and pivot shaft  259 . The sampling cartridge body  247  may also rotate about the pivot shaft  259 . In order to achieve precise relative motion between the penetrating member cartridge body  246  and the sampling cartridge body  247 , one or both of the cartridge bodies  246  and  247  may be rotatable about the pivot shaft  259 , however, it is not necessary for both to be rotatable about the pivot shaft  259 , that is, one of the cartridge bodies  246  and  247  may be secured, permanently or removably, to the pivot shaft  259 . 
     The sampling cartridge body  247  includes a base  261  and a cover sheet  262  that covers a proximal surface  263  of the base forming a fluid tight seal. Each sampling module portion  248  of the sampling cartridge body  247 , such as the sampling module portion  248 , has a sample reservoir  264  and a penetrating member channel  253 . The sample reservoir  264  has a vent  965  at an outward radial end that allows the sample reservoir  264  to readily fill with a fluid sample. The sample reservoir  264  is in fluid communication with the respective penetrating member channel  253  which extends substantially parallel to the longitudinal axis  249  of the sampling cartridge body  247 . The penetrating member channel  253  is disposed at the inward radial end of the sample reservoir  264 . Still further description of the device of  FIG. 21  may be found in commonly assigned, copending U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002. 
     Referring to  FIG. 22A , one embodiment of the present invention is a tissue penetrating system  310  with a plurality of penetrating members  312  that each have a tissue penetrating tip  314 . The number of penetrating members  310  can vary, but numbers in the ranges of 10, 15, 25, 50, 75, 100, 500 or any other number, are suitable. Each penetrating member  312  can be a lancet, a traditional lancet with a molded body, a needle with a lumen, a knife like element, an elongate member without molded attachments, and the like, and may have a size in the range of 20 mm to 10 mm in length and between 0.012-0.040 mm in diameter. It should be understood of course that penetrating members of a variety of different sizes useful for lancing such as those of conventional lancets may be used in other embodiments. As seen in  FIG. 22A , the penetrating member may have an elongate portion with a bend near a proximal end of the member. 
     Each penetrating member  312  is coupled to a penetrating member driver  316 . Suitable penetrating member drivers  316  include but are not limited to, an electric drive force member, a voice coil drive force generator, a linear voice coil device, a rotary voice coil device, and the like. Suitable drive force generators can be found in commonly assigned, copending U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002. In one embodiment, the penetrating member driver or drive force generator  316  may be a single actuator used to advance the penetrating member and to withdraw the member. The driver  316  may also be used to stop the penetrating member in the tissue site. Penetrating member driver  316  can be a non-spring actuator for drawing penetrating member  312  in a direction back towards penetrating member driver  316 . A coupler  318  on penetrating member driver  316  is configured to engage at least a portion of an elongate portion of a penetrating member  312  in order to drive the penetrating member  312  along a path into and through target tissue  320 , and then withdrawn from target tissue  320 . 
     Referring now to  FIG. 22B , the tips of the penetrating members  312  can be uncovered when they are launched into a selected target tissue  320 . In one embodiment, sterility enclosures  322  are provided for covering at least the tip of each penetrating member  312 .  FIG. 22B  shows that the enclosure may also cover the entire lancet. In one embodiment, each sterility enclosure  322  is removed from the penetrating member  312  prior to actuation, launch, of penetrating member  312  and positioned so that penetrating member  312  does not contact the associated sterility enclosure  322  during actuation. As seen in  FIG. 22B , the enclosure  322  may be peel away to reveal the penetrating member  312  prior to coupling of the member  312  to the drive force generator  316 . In another embodiment, each penetrating member  312  breaches its associated sterility enclosure  322  during launch. 
     Tissue penetrating system  310  can also include one or more penetrating member sensors  324  that are coupled to penetrating members  312 . Examples of suitable penetrating member sensors  324  include but are not limited to, a capacitive incremental encoder, an incremental encoder, an optical encoder, an interference encoder, and the like. Each penetrating member sensor  324  is configured to provide information relative to a depth of penetration of a penetrating member  312  through a target tissue  320  surface, including but not limited to a skin surface, and the like. The penetrating member sensor  324  may be positioned as shown in  FIG. 22B . The penetrating member sensor  324  may also be positioned in a variety of location such as but not limited to being closer to the distal end of the penetrating member, in a position as shown in  FIG. 5 , or in any other location useful for providing an indication of the position of a penetrating member  312  being driven by the force generator  316 . 
     In various embodiments, the penetration depth of a penetrating member  312  through the surface of a target tissue  320  can be, 100 to 2500 microns, 500 to 750 microns, and the like. Each penetrating member sensor  324  can also provide an indication of velocity of a penetrating member  312 . Referring to  FIG. 22C , a damper  326  can be coupled to penetrating member driver  316 . Damper  326  prevents multiple oscillations of penetrating member  312  in target tissue  320 , particularly after penetrating member  312  has reached a desired depth of penetration. The damper  326  may be placed in a variety of positions such as but not limited to being coupled to the penetrating member, being coupled to the coupler  318 , being coupled to a core or shaft in the drive force generator  316 , or at any other position useful for slowing the motion of the penetrating member  312 . 
     A feedback loop  328  can also be included that is coupled to penetrating member sensor  324 . Each penetrating member  312  sensor can be coupled to a processor  330  that has control instructions for penetrating member driver  316 . By way of illustration, and without limitation, processor  330  can include a memory for storage and retrieval of a set of penetrating member  312  profiles utilized with penetrating member driver  316 . Processor  330  can also be utilized to monitor position and speed of a penetrating member  312  as it moves in first direction  332  to and through the target tissue  320 . 
     Processor  330  can adjust an application of force to a penetrating member  312  in order to achieve a desired speed of a penetrating member  312 . Additionally, processor  330  can also be used to adjust an application of force applied to a penetrating member  312  when penetrating member  312  contacts target tissue  320  so that penetrating member  312  penetrates target tissue  320  within a desired range of speed. Further, processor  330  can also monitor position and speed of a penetrating member  312  as penetrating member  312  moves in first direction  332  toward the target tissue  320 . Application of a launching force to penetrating member  312  can be controlled based on position and speed of penetrating member  312 . Processor  330  can control a withdraw force, from target tissue  320 , to penetrating member  312  so that penetrating member  312  moves in second direction  334  away from target tissue  320 . 
     Processor  330  can produce a signal that is indicative of a change in direction and magnitude of force exerted on penetrating member  312 . Additionally, processor  330  can cause a braking force to be applied to penetrating member  312 . 
     In one embodiment, in first direction  332  penetrating member  312  moves toward target tissue  320  at a speed that is different than a speed at which penetrating member  312  moves away from target tissue  320  in second direction  334 . In one embodiment, the speed of penetrating member  312  in first direction  332  is greater than the speed of penetrating member  312  in second direction  334 . The speed of penetrating member  312  in first direction  332  can be a variety of different ranges including but not limited to, 0.05 to 60 m/sec, 0.1 to 20.0 m/sec, 1.0 to 10.0 m/sec, 3.0 to 8.0 m/sec, and the like. Additionally, the dwell time of penetrating member  312  in target tissue  320 , below a surface of the skin or other structure, can be in the range of, 1 microsecond to 2 seconds, 500 milliseconds to 1.5 second, 100 milliseconds to 1 second, and the like. 
     As seen in  FIGS. 22A and 22B , tissue penetrating system  310  can include a penetrating member transport device  336  for moving each of penetrating member  312  into a position for alignment with penetrating member driver  316 . Penetrating members  312  can be arranged in an array configuration by a number of different devices and structures defining support  338 , including but not limited to, a belt, a flexible or non-flexible tape device, support channel, cog, a plurality of connectors, and the like. Support  338  can have a plurality of openings each receiving a penetrating member  312 . Suitable supports  338  may also include but are not limited to, a bandolier, drum, disc and the like. A description of supports  338  can be found in commonly assigned, copending U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002; commonly assigned, copending U.S. Provisional Patent Application Ser. No. 60/437,205 filed Dec. 31, 2002; and commonly assigned, copending U.S. Provisional Patent Application Ser. No. 60/437,359 filed Dec. 31, 2002. All applications listed above are fully incorporated herein by reference for all purposes. 
     As illustrated in  FIG. 22(   a ), tissue penetrating system  310  can include a single penetrating member driver  316  and a plurality of penetrating members  312 . Penetrating member driver  316  moves each penetrating member  312  along a path out of a housing that has a penetrating member exit and then into target tissue  320 , stopping in target tissue  320 , and then withdrawing out of the target tissue  320 . Support  338  couples the penetrating members  312  to define a linear array. Support  338  is movable and configured to move each penetrating member  312  to a launch position associated with penetrating member driver  316 . Penetrating member driver  316  can be controlled to follow a predetermined velocity trajectory into and out of target tissue  320 . 
     Tissue penetrating system  310  can include a user interface  340  configured to relay different information, including but not limited to, skin penetrating performance, a skin penetrating setting, and the like. User interface  340  can provide a user with at a variety of different outputs, including but not limited to, penetration depth of a penetrating member  312 , velocity of a penetrating member  312 , a desired velocity profile, a velocity of penetrating member  312  into target tissue  320 , velocity of the penetrating member  312  out of target tissue  320 , dwell time of penetrating member  312  in target tissue  320 , a target tissue relaxation parameter, and the like. User interface  340  can include a variety of components including but not limited to, a real time clock  342 , one or more alarms  344  to provide a user with a reminder of a next target penetrating event is needed, a user interface processor  346 , and the like. 
     User interface  340  can provide a variety of different outputs to a user including but not limited to, number of penetrating members  312  available, number of penetrating members  312  used, actual depth of penetrating member  312  penetration on target tissue  320 , stratum corneum thickness in the case where the target tissue  320  is the skin and an area below the skin, force delivered on target tissue  320 , energy used by penetrating member driver  316  to drive penetrating member  312  into target tissue  320 , dwell time of penetrating member  312 , battery status of tissue penetrating system  310 , status of tissue penetrating system  310 , the amount of energy consumed by tissue penetrating system  310 , or any component of tissue penetrating system  310 , speed profile of penetrating member  312 , information relative to contact of penetrating member  312  with target tissue  320  before penetration by penetrating member  312 , information relative to a change of speed of penetrating member  312  as in travels in target tissue  320 , and the like. 
     User interface  340  can include a data interface  348  that couples tissue penetrating system  310  to support equipment  350  with an interface, the internet, and the like. The data interface  348  may also be coupled to the processor  93 . Suitable support equipment  350  includes but is not limited to, a base station, home computer, central server, main processing equipment for storing analyte, such as glucose, level information, and the like. 
     Data interface  348  can be a variety of interfaces including but not limited to, Serial RS-232, modem interface, USB, HPNA, Ethernet, optical interface, IRDA, RF interface, Bluetooth interface, cellular telephone interface, two-way pager interface, parallel port interface standard, near field magnetic coupling, RF transceiver, telephone system, and the like. 
     User interface  340  be coupled to a memory  352  that stores, a target tissue parameter, target tissue  320  penetrating performance, and the like. The memory  352  may also be connected to processor  93  and store data from the user interface  340 . 
     In one embodiment, memory  352  can store, the number of target tissue penetrating events, time and date of the last selected number of target tissue penetrating events, time interval between alarm and target tissue penetrating event, stratum corneum thickness, time of day, energy consumed by penetrating member driver  316  to drive penetrating member  312  into target tissue  320 , depth of penetrating member  312  penetration, velocity of penetrating member  312 , a desired velocity profile, velocity of penetrating member  312  into target tissue  320 , velocity of penetrating member  312  out of target tissue  320 , dwell time of penetrating member  312  in target tissue  320 , a target tissue relaxation parameter, force delivered on target tissue  320  by any component of tissue penetrating device, dwell time of penetrating member  312 , battery status of tissue penetrating system  310 , tissue penetrating system  310  status, consumed energy by tissue penetrating system  310  or any of its components, speed profile of penetrating member  312  as it penetrates and advances through target tissue  320 , a tissue target tissue relaxation parameter, information relative to contact of penetrating member  312  with target tissue  320  before penetration by penetrating member  312 , information relative to a change of speed of penetrating member  312  as in travels in and through target tissue  320 , information relative to consumed analyte detecting members, and information relative to consumed penetrating members  312 . 
     In one embodiment, processor  330  is coupled to and receives any of a different type of signals from user interface  340 . User interface  340  can respond to a variety of different commands, including but not limited to audio commands, and the like. User interface  340  can include a sensor for detecting audio commands. Information can be relayed to a user of tissue penetrating system  310  by way of an audio device, wireless device  329 , and the like. 
     In another embodiment as seen in  FIG. 23B , tissue penetrating device includes a human interface  354  with at least one output. The human interface  354  is specific for use by humans while a user interface  340  may be for any type of user, with user defined generically. Human interface  354  can be coupled to processor  330  and penetrating member sensor  324 . Human interface  354  can be a variety of different varieties including but not limited to, LED, LED digital display, LCD display, sound generator, buzzer, vibrating device, and the like. 
     The output of human interface  354  can be a variety of outputs including but not limited to, a penetration event by penetrating member  312 , number of penetrating members  312  remaining, time of day, alarm, penetrating member  312  trajectory waveform profile information, force of last penetration event, last penetration event, battery status of tissue penetrating system  310 , analyte status, time to change cassette status, jamming malfunction, tissue penetrating system  310  status, and the like. 
     Human interface  354  is coupled to a housing  356 . Suitable housings  356  include but are not limited to a, telephone, watch, PDA, electronic device, medical device, point of care device, decentralized diagnostic device and the like. An input device  358  is coupled to housing. Suitable input devices  358  include but are not limited to, one or more pushbuttons, a touch pad independent of the display device, a touch sensitive screen on a visual display, and the like. 
     A data exchange device  360  can be utilized for coupling tissue penetrating system  310  to support equipment  350  including but not limited to, personal computer, modem, PDA, computer network, and the like. Human interface  354  can include a real time clock  362 , and one or more alarms  364  that enable a user to set and use for reminders for the next target tissue penetration event. Human interface  354  can be coupled to a human interface processor  366  which is distinct from processor  330 . Human interface processor  366  can include a sleep mode and can run intermittently to conserve power. Human interface processor  366  includes logic that can provide an alarm time set for a first subset of days, and a second alarm time set for a second subset of days. By way of example, and without limitation, the first subset of days can be Monday through Friday, and the second subset of days can be Saturday and Sunday. 
     Human interface  354  can be coupled to a memory  368  for storing a variety of information, including but not limited to, the number of target tissue penetrating events, time and date of the last selected number of target tissue penetrating events, time interval between alarm and target tissue penetrating event, stratum corneum thickness when target tissue  320  is below the skin surface and underlying tissue, time of day, energy consumed by penetrating member driver  316  to drive penetrating member  312  into target tissue  320 , depth of penetrating member  312  penetration, velocity of penetrating member  312 , a desired velocity profile, velocity of penetrating member  312  into target tissue  320 , velocity of penetrating member  312  out of target tissue  320 , dwell time of penetrating member  312  in target tissue  320 , a target tissue relaxation parameter, force delivered on target tissue  320 , dwell time of penetrating member  312 , battery status of tissue penetrating system  310  and its components, tissue penetrating system  310  status, consumed energy, speed profile of penetrating member  312  as it advances through target tissue  320 , a target tissue relaxation parameter, information relative to contact of a penetrating member  312  with target tissue  320  before penetration by penetrating member  312 , information relative to a change of speed of penetrating member  312  as in travels in target tissue  320 , information relative to consumed sensors, information relative to consumed penetrating members  312 . 
     As illustrated in  FIG. 24 , tissue penetrating system  310  can include a penetrating member driver  316  and a plurality of cartridges  370 . Each cartridge  370  contains a penetrating member  312 . The cartridges  370  can be coupled together in an array, which can be a flexible array. A cartridge transport device  372  moves cartridges  370  into a launch position that operatively couples a penetrating member  312  to penetrating member driver  316 . A support couples cartridges  370  to define an array. A plurality of sterility enclosures  322  can be provided to at least cover tips of penetrating members  312 . Sterility enclosure  322  (shown in phantom) is removed from their associated penetrating members  312  prior to launch of the penetrating member  312 . The enclosure may be peeled away (not shown) in a manner similar to that as seen in  FIG. 22B , with the enclosure  322  on one tape surface being peeled away. The enclosure  322  may be a blister sack, a sack tightly formed about each cartridge  370 , or other enclosure useful for maintaining a sterile environment about the cartridge  370  prior to actuation or launch. The enclosure  322  may contain the entire cartridge  370  or some portion of the cartridge  370  which may need to remain sterile prior to launch. During launch, enclosure or sterility barrier  322  can be breached by a device other than penetrating member  312 , or can be breached by penetrating member  312  itself. An analyte detection member, sensor, may be positioned to receive fluid from a wound created by the penetrating member  312 . The member may be on the cartridge  370  or may be on the device  80 . 
     Referring to  FIGS. 24 and 25 , one embodiment of tissue penetrating system  310  includes cartridge transport device  372  and a plurality of cartridges  370 . Each cartridge  370  is associated with a penetrating member  312 . Cartridge transport device  372  moves each cartridge  370  to a position to align the associated penetrating member  312  with penetrating member driver  316  to drive penetrating member  312  along a path into target tissue  320 . In one embodiment as seen in  FIG. 25 , each cartridge  370  has at least one of a distal port  374  and a proximal port  376 . A first seal  378  is positioned at distal or proximal ports. As seen in  FIG. 25 , the seal  378  may be placed at the distal port. First seal  378  is formed of a material that is fractured by penetrating member  312  before it is launched. A second seal  380  can be positioned at the other port. It will be appreciated that only one or both of distal and proximal ports  374  and  376  can be sealed, and that each cartridge  370  can include only one port  374  and  376 . For ease of illustration, the penetrating member  312  extending longitudinally through the lumen in the cartridge  370  is not shown. The seals  380  and  378  may be fracturable seals formed between the penetrating member and the cartridge  370 . During actuation, the seals  378  and  380  are broken. Seal  378  may be also be positioned to cover the distal port or exit port  374  without being sealed against the penetrating member (i.e. covering the port without touching the penetrating member). A third seal  381  may be positioned to cover an entrance to sample chamber  384 . The seal  381  may be configured to be broken when the penetrating member  312  is actuated. A still further seal  381 A may be placed in the lumen. The tip of a penetrating member may be located at any position along the lumen, and may also be at or surrounded by one of the seals  378 ,  381 ,  381 A, or  376 . 
     Referring still to  FIG. 25 , a cover sheet  383  may be a flexible polymer sheet as described in commonly assigned, copending U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002. It should be understood of course that the sheet may be made of a variety of materials useful for coupling an analyte detecting member  390 . This allows the analyte detecting member  390  to be sterilized separately from the cartridge  370  and assembled together with the cartridge at a later time. This process may be used on certain analyte detecting members  390  that may be damaged if exposed to the sterilization process used on the cartridge  370 . Of course, some embodiments may also have the analyte detecting member  390  coupled to the cartridge  370  during sterilization. The cover sheet  383  may also form part of the seal to maintain a sterile environment about portions of the penetrating member. In other embodiments, the lumen housing penetrating member may be enclosed and not use a sheet  383  to help form a sterile environment. In still further embodiments, the sheet  383  may be sized to focus on covering sample chamber  384 . 
     As illustrated in  FIG. 26 , cartridge  370  has at least one port  374 . A plurality of penetrating members  312  are in cartridge  370 . Although cartridge  370  is shown in  FIG. 26  to have a linear design, the cartridge  370  may also have a curved, round, circular, triangular, or other configuration useful for positioning a penetrating member for use with a drive force generator. A seal  382  is associated with each penetrating member  312  in order to maintain each penetrating member  312  in a sterile environment in cartridge  370  prior to launch. Prior to launch, seal  382  associated with the penetrating member  312  to be launched is broken. In one embodiment, a punch (not shown) is used to push down on the seal  382  covering the port  376  of the cartridge  370 . This breaks the seal  382  and also pushes it downward, allowing the penetrating member to exit the cartridge without contacting the seal  382 . The timing of the breaking of the seal  382  may be varied so long as the penetrating member remains substantially sterile when being launched towards the tissue site  320 . In other embodiments, the port  376  may have a seal  383  that protrudes outward and is broken off by the downward motion of the punch. One or more sample chambers  384  are included in cartridge  370 . In one embodiment, each penetrating member  312  has an associated sample chamber  384 . In one embodiment, illustrated in  FIG. 27 , penetrating member  312  is extendable through an opening  386  of its associated sample chamber  384 . In some embodiments, a seal  387  may be included in the sample chamber  384 . Seals  382  and  387  may be made from a variety of materials such as but not limited to metallic foil, aluminum foil, paper, polymeric material, or laminates combining any of the above. The seals may also be made of a fracturable material. The seals may be made of a material that can easily be broken when a device applies a force thereto. The seals alone or in combination with other barriers may be used to create a sterile environment about at least the tip of the penetrating member prior to lancing or actuation. 
     With reference now to the embodiment of  FIG. 28 , each sample chamber  384  may have an opening  388  for transport of a body fluid into the sample chamber  384 . The size of sample chambers  384  in  FIGS. 26 through 28  can vary. In various embodiments, sample chambers  384  are sized to receive, no more than 1.0 μL of the body fluid, no more than 0.75 μL of the body fluid, no more than 0.5 μL of the body fluid, no more than 0.25 μL of the body fluid, no more than 0.1 μL of the body fluid, and the like. It will be appreciated that sample chambers  384  can have larger or smaller sizes. 
     An analyte detecting member  390  may associated with each sample chamber  384 . The analyte detecting member  390  may be designed for use with a variety of different sensing techniques as described in commonly assigned, copending U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002. Analyte detecting member  390  can be positioned in sample chamber  384 , at an exterior of sample chamber  384 , or at other locations useful for obtaining an analyte. Analyte detecting member  390  can be in a well  392 , or merely be placed on a support. 
     In one embodiment, analyte detecting member  390  includes chemistries that are utilized to measure and detect glucose, and other analytes. In another embodiment, analyte detecting member  390  is utilized to detect and measure the amount of different analytes in a body fluid or sample. In various embodiments, analyte detecting member  390  determines a concentration of an analyte in a body fluid using a sample that does not exceed a volume of, 1 μL of a body fluid disposed in sample chamber  384 , 0.75 μL of a body fluid disposed in sample chamber  384 , 0.5 μL of a body fluid disposed in sample chamber  384 , 0.25 μL of a body fluid disposed in sample chamber  384 , 0.1 μL of a body fluid disposed in sample chamber  384 , and the like. For example and not by way of limitation, the sample chamber  384  may be of a size larger than the volumes above, but the analyte detecting member  390  can obtain an analyte reading using the amounts of fluid described above. 
     As illustrated in  FIG. 29 , tissue penetrating system  310  can include a housing member  394 , a penetrating member  312  positioned in housing member  394 , and analyte detecting member  390  coupled to a sample chamber  384 . Analyte detecting member  390  is configured to determine a concentration of an analyte in a body fluid using with a variety of different body fluid, sample, volumes. In various embodiments, the volume is less than 1 μL of body fluid disposed in sample chamber  384 , 0.75 of body fluid disposed in sample chamber  384 , 0.5 of body fluid disposed in sample chamber  384 , 0.25 of body fluid disposed in sample chamber  384 , 0.1 of body fluid disposed in sample chamber  384  and the like. Each tip of a penetrating member  312  is configured to extend through an opening of sample chamber  384 . A plurality of penetrating members  312  can be positioned in housing member  394 . Housing member  394  can be the same as cartridge  370 . Cartridge  370  can have distal and proximal ports  374  and  376 , respectively. Additionally, in this embodiment, a plurality of cartridges  370  can be provided, each associated with a penetrating member  312 . 
     Referring to  FIG. 30 , each penetrating member  312  has a packing density, or occupied volume, in cartridge  370 . In various embodiments, the packing density of each penetrating member  312  in cartridge  370  can be no more than, 5.0 cm 3 /penetrating member  312 , 4.0 cm 3 /penetrating member  312 , 3.0 cm 3 /penetrating member  312 , 2.0 cm 3 /penetrating member  312 , 1.0 cm 3 /penetrating member  312 , 0.75 cm 3 /penetrating member  312 , 0.5 cm 3 /penetrating member  312 , 0.25 cm 3 /penetrating member  312 , 0.1 cm 3 /penetrating member  312 , and the like. In other words, the volume required for each penetrating member does not exceed 5.0 cm 3 /penetrating member  312 , 4.0 cm 3 /penetrating member  312 , 3.0 cm 3 /penetrating member  312 , 2.0 cm 3 /penetrating member  312 , 1.0 cm3/penetrating member  312 , 0.75 cm3/penetrating member  312 , 0.5 cm 3 /penetrating member  312 , 0.25 cm 3 /penetrating member  312 , 0.1 cm 3 /penetrating member  312 , and the like. So, as seen in  FIG. 30 , if the total package volume of the cartridge is defined as X and the cartridge includes Y number of penetrating members  312 , penetrating members  312  and test area, or other unit  395 , the volume for each unit does not exceed 5.0 cm 3 /unit, 4.0 cm 3 /unit, 3.0 cm 3 /unit, 2.0 cm 3 /unit, 1.0 cm 3 /unit, 0.75 cm 3 /unit, 0.5 cm 3 /unit, 0.25 cm 3 /unit, 0.1 cm 3 /unit, and the like. 
     In various embodiments, each penetrating member  312  and its associated sample chamber  384  have a combined packing density of no more than about 5.0 cm 3 , 4.0 cm 3 , 3.0 cm 3 , 2.0 cm 3 , 1.0 cm 3 , 0.75 cm 3 , 0.5 cm 3 , 0.25 cm 3 , 0.1 cm 3 , and the like. 
     With reference now to  FIG. 31 , tissue penetrating system  310  can have a first seal  378  formed at distal port  374  and a second seal  380  formed at proximal port  376  of cartridge  370 . Prior to launching of penetrating member  312 , distal seal  378  and second seal  380  maintain a distal tip of penetrating member  312  and sample chamber  384  in a sterile environment. Second seal  380  is breached, and penetrating member  312  is then launched. 
     As illustrated in  FIG. 32 , a plurality of lumens  396  can be positioned between distal port  374  and proximal port  376  of cartridge  370  for slidably receiving a penetrating member  312 . Sample chamber  384  is defined by cartridge  370 , has an opening  398  and is associated with penetrating member  312 . First seal  378  covers distal port  374 , and a second seal  380  covers proximal port  376 . 
     In another embodiment as shown in  FIG. 33 , tissue penetrating system  310  includes a plurality of cartridges  370 , penetrating member driver  316 , and a plurality of penetrating members  312  coupled to penetrating member driver  316 . Each penetrating member  312  is associated with a cartridge  370 . A plurality of gas-tightly sealed enclosures  400  are coupled in an array. Each enclosure  400  fully contains at least one of cartridge  370 . Enclosures  400  are configured to be advanceable on cartridge transport device  372  that individually releases cartridges  370  from sacks or enclosures  400  and loads them individually onto penetrating member driver  316 . The enclosures  400  may be removed by peeling back a top portion of the tape as shown in  FIG. 22B . 
     In another embodiment, a plurality of penetrating members  312  each have a sharpened distal tip. A penetrating member driver  316  is coupled to each penetrating member  312 . A plurality of cartridges  370  are coupled in an array. Each cartridge  370  houses a penetrating member  312  and is configured to permit penetrating member driver  316  to engage each of penetrating members  312  sequentially. Each cartridge  370  has a plurality of seals positioned to provide that the sharpened distal tips remain in a sterile environment before penetrating target tissue  320 . Penetrating members  312  are launched without breaking a seal using the penetrating member. 
     Referring now to  FIG. 34 , a plurality of cartridges  370  are provided, each having distal and proximal ports  374  and  376 , respectively. A plurality of penetrating members  312  are each associated with a cartridge  370 . Each penetrating member  312  has a sharpened distal tip and a shaft portion slidably disposed within cartridge  370 . As seen in  FIG. 34 , the cartridges  370  may be coupled together by a connector or flexible support  403 . A seal  404  is formed by a fracturable material between the penetrating member  312  and each cartridge  370 . Seal  404  is positioned in at least one of distal or proximal ports  374  and  376 , respectively, of cartridge  370 . Cartridge transport device  372  moves each cartridge  370  to a position  405  that aligns penetrating member  312  with penetrating member driver  316  so that penetrating member  312  can be driven along a path into target tissue  320 . 
     In another embodiment of the present invention as seen in  FIG. 35 , tissue penetrating system  310  includes a housing member  406 , the plurality of penetrating members  312  positioned in housing member  406 , and a tissue stabilizing member  408 , which can also be a pressure applicator, stimulating member, stimulating vibratory member that imparts motion to a tissue surface, and the like. Tissue stabilizing member  408  can be positioned to at least partially surround an impact location of the penetrating member  312  on the target tissue  320  site. Tissue stabilizing member  408  can, enhance fluid flow from target tissue  320 , stretch a target tissue  320  surface, apply a vacuum to target tissue  320 , apply a force to target tissue  320  and cause target tissue  320  to press in an inward direction relative to housing member  406 , apply a stimulation to target tissue  320 , and the like. Tissue stabilizing member  408  can have a variety of different configurations. In one embodiment, tissue stabilizer member  408  includes a plurality of protrusions  410 . In some further embodiments, a vacuum source  412  may be provided to assist the creation of a low pressure environment in the tissue stabilizing member  408  or along the fluid path to a sample chamber associated with the system  310 . In some embodiments, the tissue stabilizing member  408  is mounted on the cartridge  370 . In other embodiments, the member  408  may be mounted on the housing  406 . The member  408  may also be pressed against the tissue site  320  and act as a pressure applicator. The member  408  may also be used against a variety of tissue including but not limited to skin or other body tissue. 
     Referring now to  FIGS. 36 and 37 , a cartridge  370  is shown with a penetrating member  312  creating a wound W in the tissue site  320 . In  FIG. 36 , a movable capillary member  420  is extended towards the wound W as indicated by arrow  422  to gather body fluid being expressed from the wound. The fluid may be drawn to a sample chamber  384  (not shown). In  FIG. 37 , the wound W is created and then the entire cartridge is moved to the tissue site  320  to gather body fluid from the wound W. In some embodiments, the cartridge  370  moves towards the wound W relative to the housing  406 . 
     Tissue penetrating systems  310  of  FIGS. 22 through 37 , can be utilized in a variety of different applications to detect any number of different analytes, including but not limited to glucose. The systems  310  may be used to measure potassium, other ions, or analytes associated with the process of glucose monitoring. The analyte detecting member  390  may further be adapted to measure other analytes found in body fluid. 
     In a still further embodiment, penetrating member  312  may be moved and positioned to be in engagement with penetrating member driver  316 . Penetrating member  312  is in a sterile environment, and prior to launch, the sterilizing covering, which can be a seal is removed. Tissue stabilizing member can apply a stimulation to a surface of the target tissue  320  prior to, and during penetration by penetration member. Penetrating member  312  is engaged with penetrating driving member and controllably pierces a target tissue  320  site. Penetrating member sensor  324  is utilized to control penetration depth and velocity of penetrating member  312 . Penetrating member  312  is stopped at a desired depth below a surface of target tissue  320  in order to reduce or eliminate without multiple oscillations against the surface of target tissue  320 . A wound is created, causing blood to flow into sample chamber  384 . In various embodiments, no more than 1 μL of a body fluid is collected in sample chamber  384 . 
     A number of different preferences, options, embodiment, and features have been given above, and following any one of these may results in an embodiment of this invention that is more presently preferred than a embodiment in which that particular preference is not followed. These preferences, options, embodiment, and features may be generally independent, and additive; and following more than one of these preferences may result in a more presently preferred embodiment than one in which fewer of the preferences are followed. 
     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 may be made without departing from the spirit and scope of the invention. Any of the embodiments of the invention may be modified to include any of the features described above or feature incorporated by reference herein. For example, the cartridge of  FIG. 26  may be adapted to include a distal portion with a tissue stabilizing member. The cartridge of  FIG. 26  may be adapted for use with a vacuum device. The cartridge may include indexing features such as notches on the distal portion or outer radial periphery for those cartridges with a radial configuration. The notches will facilitate positioning, among other things, and may be used for movement. Other cartridges or tapes herein may be modified with notches or tractor holes to facilitate movement. User interfaces, human interfaces, and other interfaces may be added to any of the embodiments of the present invention. 
     With any of the above embodiments, the location of the penetrating member drive device may be varied, relative to the penetrating members or the cartridge. With any of the above embodiments, the penetrating member tips may be uncovered during actuation (i.e. penetrating members do not pierce the penetrating member enclosure or protective foil during launch). With any of the above embodiments, the penetrating members may be a bare penetrating member during launch. With any of the above embodiments, the penetrating members may be bare penetrating members prior to launch as this may allow for significantly tighter densities of penetrating members. In some embodiments, the penetrating members may be bent, curved, textured, shaped, or otherwise treated at a proximal end or area to facilitate handling by an actuator. The penetrating member may be configured to have a notch or groove to facilitate coupling to a gripper or coupler. The notch or groove may be formed along an elongate portion of the penetrating member. The coupler may be designed to create a frictional only type grip on the penetrating member. 
     With any of the above embodiments, any open cavity housing the penetrating may be on the bottom or the top of the cartridge, with the gripper on the other side. In some embodiments, sensors may be printed on the top, bottom, or side of the cavities. The front end of the cartridge maybe in contact with a user during lancing. The same driver may be used for advancing and retraction of the penetrating member. The penetrating member may have a diameters and length suitable for obtaining the blood volumes described herein. The penetrating member driver may also be in substantially the same plane as the cartridge. The driver may use a through hole or other opening to engage a proximal end of a penetrating member to actuate the penetrating member along a path into and out of the tissue. 
     Any of the features described in this application or any reference disclosed herein may be adapted for use with any embodiment of the present invention. For example, the devices of the present invention may also be combined for use with injection penetrating members or needles as described in commonly assigned, copending U.S. patent application Ser. No. 10/127,395 filed Apr. 19, 2002. A sensor to detect the presence of foil may also be included in the lancing apparatus. For example, if a cavity has been used before, the foil or sterility barrier will be punched. The sensor can detect if the cavity is fresh or not based on the status of the barrier. It should be understood that in optional embodiments, the sterility barrier may be designed to pierce a sterility barrier of thickness that does not dull a tip of the penetrating member. The lancing apparatus may also use improved drive mechanisms. For example, a solenoid force generator may be improved to try to increase the amount of force the solenoid can generate for a given current. A solenoid for use with the present invention may have five coils and in the present embodiment the slug is roughly the size of two coils. One change is to increase the thickness of the outer metal shell or windings surround the coils. By increasing the thickness, the flux will also be increased. The slug may be split; two smaller slugs may also be used and offset by ½ of a coil pitch. This allows more slugs to be approaching a coil where it could be accelerated. This creates more events where a slug is approaching a coil, creating a more efficient system. 
     In another optional alternative embodiment, a gripper in the inner end of the protective cavity may hold the penetrating member during shipment and after use, eliminating the feature of using the foil, protective end, or other part to retain the used penetrating member. Some other advantages of the disclosed embodiments and features of additional embodiments include: same mechanism for transferring the used penetrating members to a storage area; a high number of penetrating members such as 25, 50, 75, 100, 500, or more penetrating members may be put on a disk or cartridge; molded body about a penetrating member becomes unnecessary; manufacturing of multiple penetrating member devices is simplified through the use of cartridges; handling is possible of bare rods metal wires, without any additional structural features, to actuate them into tissue; maintaining extreme (better than 50 micron-lateral- and better than 20 micron vertical) precision in guiding; and storage system for new and used penetrating members, with individual cavities/slots is provided. The housing of the lancing device may also be sized to be ergonomically pleasing. In one embodiment, the device has a width of about 56 mm, a length of about 105 mm and a thickness of about 15 mm. Additionally, some embodiments of the present invention may be used with non-electrical force generators or drive mechanism. For example, the punch device and methods for releasing the penetrating members from sterile enclosures could be adapted for use with spring based launchers. The gripper using a frictional coupling may also be adapted for use with other drive technologies. 
     Still further optional features may be included with the present invention. For example, with any of the above embodiments, the location of the penetrating member drive device may be varied, relative to the penetrating members or the cartridge. With any of the above embodiments, the penetrating member tips may be uncovered during actuation (i.e. penetrating members do not pierce the penetrating member enclosure or protective foil during launch). The penetrating members may be a bare penetrating member during launch. The same driver may be used for advancing and retraction of the penetrating member. Different analyte detecting members detecting different ranges of glucose concentration, different analytes, or the like may be combined for use with each penetrating member. Non-potentiometric measurement techniques may also be used for analyte detection. For example, direct electron transfer of glucose oxidase molecules adsorbed onto carbon nanotube powder microelectrode may be used to measure glucose levels. In all methods, nanoscopic wire growth can be carried out via chemical vapor deposition (CVD). In all of the embodiments of the invention, preferred nanoscopic wires may be nanotubes. Any method useful for depositing a glucose oxidase or other analyte detection material on a nanowire or nanotube may be used with the present invention. 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.