Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/151—Devices specially adapted for taking samples of capillary blood, e.g. by lancets, needles or blades
  • A61B5/15186—Devices loaded with a single lancet, i.e. a single lancet with or without a casing is loaded into a reusable drive device and then discarded after use; drive devices reloadable for multiple use
  • A61B5/15188—Constructional features of reusable driving devices
  • A61B5/15192—Constructional features of reusable driving devices comprising driving means, e.g. a spring, for retracting the lancet unit into the driving device housing
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/14—Devices for taking samples of blood ; Measuring characteristics of blood in vivo, e.g. gas concentration within the blood, pH-value of blood
  • A61B5/1405—Devices for taking blood samples
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue
  • A61B5/14546—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/150007—Details
  • A61B5/150015—Source of blood
  • A61B5/150022—Source of blood for capillary blood or interstitial fluid
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/150007—Details
  • A61B5/150053—Details for enhanced collection of blood or interstitial fluid at the sample site, e.g. by applying compression, heat, vibration, ultrasound, suction or vacuum to tissue; for reduction of pain or discomfort; Skin piercing elements, e.g. blades, needles, lancets or canulas, with adjustable piercing speed
  • A61B5/150061—Means for enhancing collection
  • A61B5/150099—Means for enhancing collection by negative pressure, other than vacuum extraction into a syringe by pulling on the piston rod or into pre-evacuated tubes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/150007—Details
  • A61B5/150374—Details of piercing elements or protective means for preventing accidental injuries by such piercing elements
  • A61B5/150381—Design of piercing elements
  • A61B5/150389—Hollow piercing elements, e.g. canulas, needles, for piercing the skin
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/150007—Details
  • A61B5/150374—Details of piercing elements or protective means for preventing accidental injuries by such piercing elements
  • A61B5/150381—Design of piercing elements
  • A61B5/150503—Single-ended needles
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/150007—Details
  • A61B5/150755—Blood sample preparation for further analysis, e.g. by separating blood components or by mixing
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/151—Devices specially adapted for taking samples of capillary blood, e.g. by lancets, needles or blades
  • A61B5/15101—Details
  • A61B5/15103—Piercing procedure
  • A61B5/15107—Piercing being assisted by a triggering mechanism
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/151—Devices specially adapted for taking samples of capillary blood, e.g. by lancets, needles or blades
  • A61B5/15101—Details
  • A61B5/15115—Driving means for propelling the piercing element to pierce the skin, e.g. comprising mechanisms based on shape memory alloys, magnetism, solenoids, piezoelectric effect, biased elements, resilient elements, vacuum or compressed fluids
  • A61B5/15117—Driving means for propelling the piercing element to pierce the skin, e.g. comprising mechanisms based on shape memory alloys, magnetism, solenoids, piezoelectric effect, biased elements, resilient elements, vacuum or compressed fluids comprising biased elements, resilient elements or a spring, e.g. a helical spring, leaf spring, or elastic strap
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/15—Devices for taking samples of blood
  • A61B5/151—Devices specially adapted for taking samples of capillary blood, e.g. by lancets, needles or blades
  • A61B5/15186—Devices loaded with a single lancet, i.e. a single lancet with or without a casing is loaded into a reusable drive device and then discarded after use; drive devices reloadable for multiple use
  • A61B5/15188—Constructional features of reusable driving devices
  • A61B5/1519—Constructional features of reusable driving devices comprising driving means, e.g. a spring, for propelling the piercing unit
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue
  • A61B5/14532—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue for measuring glucose, e.g. by tissue impedance measurement

Definitions

• the present invention relates generally to testing systems for determining the concentration of an analyte in a fluid sample, and more particularly, to a system for lancing a test subject's skin, harvesting a body fluid sample, and determining the concentration of an analyte in the body fluid sample.
• BACKGROUND OF THE INVENTION It is often necessary to quickly obtain a sample of blood and perform an analysis of the blood sample.
• One example of a need for obtaining a sample of blood is in connection with a blood glucose monitoring system, which a user must frequently use to monitor the user's blood glucose level.
• One method of obtaining a blood sample and analyzing the sample for determining the glucose level is with a lancing device and a separate blood collection device.
• obtaining a blood sample a drop of blood is obtained from the fingertip using the lancing device, and the blood is harvested using a test strip, which is then analyzed by a test unit to determine the glucose concentration in the blood, often using an electrochemical- or colorimetric-based analysis.
• Test strips are also used for determining the concentration or presence of various other analytes ⁇ e.g., fructosamine, hemoglobin, cholesterol, glucose, alcohol, drugs including illegal drugs, etcX) in a variety of body fluids ⁇ e.g., blood, interstitial fluid, saliva, urine, etc.).
• body fluids e.g., blood, interstitial fluid, saliva, urine, etc.
• a drawback associated with using physically separate lancing and collection devices is that a patient/user must manipulate two different instruments requiring the user/patient to bring the collection device ⁇ e.g., the test strip) to the area of skin that has been lanced to collect the sample. Because the user must align the collection device with the sample to be collected, a larger than necessary sample amount is often produced and collected to ensure an accurate analysis.
• the method comprises the acts of lancing the skin of a test subject with the hollow lancet having an interior of the hollow lancet that forms a capillary channel, collecting a body fluid sample from the lanced skin in the capillary channel of the hollow lancet, and analyzing the body fluid sample for determining the analyte concentration in the body fluid sample while the collected body fluid sample remains in the lancet.
• FIG. 1 is a side view of a lancing device according to one embodiment of the present invention.
• FIG. 2 is an enlarged cross-sectional view of the forward end of the lancing device of FIG. 1.
• FIG. 3 is an enlarged cross-sectional view of the forward end of the lancing device of FIG. 1 shown while lancing a test subject's skin.
• FIG. 4 is an enlarged cross-sectional view of the forward end of the lancing device of FIG. 1 shown while harvesting a body fluid sample.
• FIG. 5 is a side view of a lancing device according to an another embodiment of the present invention.
• FIG. 6 is a side view of a vacuum-assisted lancing device according to another embodiment of the present invention.
• FIGS. 1 and 2 a lancing device 10 according to one embodiment of the present invention is shown.
• the lancing device 10 is vacuum assisted as is described in detail below and as is known in the art.
• the device 10 includes a body 12 that houses a plunger 14 and a lancing mechanism 16 for driving a lancet 18.
• a top end 20 of the plunger 14 extends beyond the body 12.
• a user grasps the device 10 by the body 12 and depresses the top end 20 of the plunger 14 — moving the plunger 14 into the body 12 of the device 10 — -to downwardly advance the lancet 18 into a test subject's skin.
• the lancet 18, one end of which is embedded in a base 22, is removably attached to a lancet holder 24, which is coupled to the plunger 14 through the lancing mechanism 16 within the body 12.
• An end cap including an outer end cap 30 and an inner-locating end cap 32 are removably attached to a forward end 34 of the device 10 opposite the plunger 14.
• the inner- locating end cap 32 is located within the outer end cap 30.
• the outer end cap 30 contacts a test subject's skin, and the test subject's skin is pulled against the inner end cap 32 during the ensuing lancing operation for puncturing the test subject's skin and collecting the sample produced at the lance site.
• Both the outer end cap 30 and the inner end cap 32 have open ends 36, 38 though which the lancet 18 passes to puncture a test subject's skin during the lancing operation.
• the end caps are removably attached to the lancing device 10 so that a used lancet can be replaced with a new lancet after a lancing procedure.
• the end caps which may come into contact with a sample during testing, may also be disposable in some embodiments of the present invention.
• the outer and inner end caps 30, 32 are integrally formed such that detaching the outer end cap 30 from the forward end 34 of the device 10 also removes the inner end cap 32.
• the lancet 18 is constructed of a substantially optically clear material and includes a micro-capillary channel according to one embodiment of the present invention.
• the lancet 18 has a hollow interior, which forms the micro-capillary channel.
• the micro-capillary channel includes a reagent or enzymatic indicator system disposed along its inner walls.
• the lancet 18 is used to both puncture a test subject's skin and then to harvest the body fluid sample produced at the puncture site.
• the analyte of interest e.g., glucose
• the reagent disposed within the lancet 18 reacts with the reagent disposed within the lancet 18 to produce a colorimetric reaction indicative of the concentration of the analyte in the sample. This reaction is then measured by an optical readhead such as a light detector.
• the lancet 18 is used for puncturing the test subject's skin, harvesting a sample produced at the punctured area of the test subject's skin, and for providing an area within the lancet 18 that the harvested sample reacts with the reagent.
• the lancet 18 is a microcapillary tube constructed of fused silica and has a polygonal cross section ⁇ e.g., rectangular, square, hexagonal, etc.)
• the lancet 18 is constructed of another substantially optically clear material such as, for example, pyrex, quartz, acrylic, polycarbonate, or polyester.
• the puncturing end or tip 40 of the microcapillary tube lancet 18 is cleaved as shown in FIG.
• the lancet 18 has a square cross section having an outer dimension of about 300 microns, which is smaller than a 360 micron diameter of a typical 28-gauge steel lancet, resulting in a small puncture site on a test subject's skin. A smaller laceration is desirable because it translates to less pain for the test subject.
• the fused silica microcapillary tubing for use in constructing the lancet 18 is commercially available having interior channel widths of about 50, 75, or 100 microns, with corresponding volumes of about 13, 29, and 50 nanoliters ("nl"), respectively, for a lancet 18 having a length of about 5 ram, which can used in alternative embodiments of the present invention.
• the fused silica microcapillary tubing for use in constructing the lancet 18 according to one embodiment of the present invention is commercially available from Polymicro Technologies, LLC of Phoenix, Arizona.
• the flat surfaces of the lancet 18 provide a substantially optically clear window for transmitting light through the sample. As is described below, transmission spectroscopy may be used to analyze the sample.
• the absorbance of the sample reacted with the analyte in the lancet 18 is used to determine analyte concentration.
• the transmission of light through fused silica for example, is spectrally flat from the ultra-violet region ⁇ e.g., wavelengths ranging from about 350 mn to about 2000 run) into the infrared region.
• the square fused microcapillary lancet 18 reduces the path length error associated with transmission spectroscopy measurements. For example, the path length error is limited to one tolerance inside the square fused silica microcapillary lancet 18.
• a fused silica microcapillary tube with a path length of 100 microns has a path length tolerance of ⁇ 5 ⁇ m, which reduces errors occurring in the analyte concentration analysis.
• Another advantage of the lancet 18 having a square cross section is that square shape provides a two-fold increase in transverse optical interaction path length wl ⁇ en compared to round capillaries.
• the square lancet 18 can be smaller than round capillaries used in a optical transmission environment, resulting in a smaller sample (e.g. . as low as about 8 ⁇ l) for filing the square lancet 18 and a smaller puncture on a test subject's skin. Referring to FIGS.
• the open end 36 of the outer end cap 30 is placed on an area of the test subject's skin ⁇ e.g. , a forearm or finger).
• the plunger 14 is depressed to advance the lancet 18 from a retracted position (FIG. 2), wherein the lancet 18 is completely contained within the end caps 30, 32, to a lancing position (FIG. 3), wherein the lancet 18 extends through the open ends 36, 28 of the end caps 30, 32 and into the test subject's skin S. Movement of the plunger 14 by the user triggers a drive spring within the lancing mechanism 16 that advances the lancet 18 into a test subject's skin S.
• the lancing device 10 is vacuum-assisted to facilitate the production of a blood sample at the puncture site on the test subject's skin.
• the outer end cap 30 forms a substantially airtight seal with the forward end 34 of the device 10.
• the lancing device 10 includes a vacuum member 44 such as a diaphragm or bellows that displaces air within the lancing device 10 and the end cap 30.
• the vacuum member 30 which evacuates air from the inner and outer end caps 14, 18.
• the vacuum member 44 When the vacuum member 44 is activated, the test subject's skin S is drawn inside the outer end cap 14 to the inner-locating end cap 32 as is depicted in FIG. 3. As the created vacuum pulls the test subject's skin S into the device 10, the test subject's skin S bulges around the locating end cap 32. The test subject's skin S is stretched flat across the open end 38 of the inner end cap 32. This stretched, flat skin facilitates sample formation and collection. The vacuum holds the skin and puncture sight in a fixed position while the sample harvesting occurs. Referring now to FIG.
• a body fluid sample B ⁇ e.g., blood
• the lancet 18 is hollow for harvesting the body fluid sample produced at the lance site.
• the lancing mechanism 16 holds the skin under vacuum and positions the hollow tip 40 of the lancet 18 in a collection position adjacent the lance site for collecting the produced body fluid sample B.
• the sample B contacts the hollow lancet 18 and the sample moves into the lancet 18 via capillary action. If the tip 40 of the microcapillary lancet 18 rests too far from the skin S, the sample B will not be drawn into the microcapillary channel.
• a reagent or enzymatic indicator system is disposed within the lancet 18 for reacting with the analyte of interest in the harvested sample for producing a colorimetric reaction indicative of the analyte concentration in the body fluid sample.
• the colorimetric reaction is read by optical instruments as it described below in connection with FIG. 5. Colorimetric testing is described in detail in U.S. Patents
• the lancing mechanism 16 retracts the lancet 18 away from the skin S ⁇ i.e., into the lancing device 10) after the sample B is collected from the lance site on the skin S for analyzing the blood according to one embodiment of the present invention.
• the lancing device 10 may maintain the lancet 18 in the collection position for analyzing the analyte concentration in the blood sample.
• the lancing device 10 includes an illumination unit 60, which may include a light source such as an LED, illumination optics for directing and collimating light, or both.
• the illumination unit 60 may comprise the output end of a fiber optic cable that pipes in light from a light source.
• the colorimetric reaction within the substantially optically clear lancet 18 between the reagent and the analyte of interest in the harvested body fluid sample is measured using transmission spectroscopy.
• the illumination unit 60 outputs a monochromatic collimated beam of light 62 onto the microcapillary lancet 18.
• Light transmitted through the microcapillary lancet 18 referred to with reference number 64 — is detected by a light detector 66 that outputs a signal indicative of the received light.
• the detected transmitted light is then compared to a reference sample ⁇ e.g., light from the source directly detected by the detector without the sample or lancet 18 present).
• the difference in light absorption between the two is used to determine the analyte concentration in the blood sample.
• the results of the analysis axe communicated to the user via a user interface including a display (not shown) of the lancing device 10.
• the amount of light transmitted through the sample is used to determine the time at which to begin analyzing the reaction between the reagent and the analyte of interest.
• the detector 66 may constantly detect light transmitted through the lancet 18 upon retracting the lancet 18 to analyze the sample.
• the processor waits a predetermined about of time after the expiration of which the transmitted light detected by the detector 66 is used by the processor to determine the analyte concentration in the fluid sample. Because the colorimetric reaction requires a predetermined about of time to develop, only transmitted light detected after the expiration of the predetermined time are used in the analysis. Waiting for the reaction to develop guards against an inaccurate analysis according to one embodiment of the present invention.
• FIG. 6 a vacuum-assisted lancing device 100 is shown, which may be adapted for use as the lancing device 10 according to an alternative embodiment of the present invention.
• a vacuum member, such as a diaphragm 138, within the lancing device 100 is activated when the plunger 112 is depressed by the user and travels toward the open end of the lancing device 100.
• a rebound spring 132 captured between a return 134 and a release 136 is expanded and extended. This action displaces the rolling diaphragm 138 toward the end cap 114.
• a central portion of the rolling diaphragm 138 is secured to the stem of the plunger 112 and a piston 140 such that the central portion moves with the plunger

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• Health & Medical Sciences (AREA)
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• Physics & Mathematics (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• Pathology (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Medical Informatics (AREA)
• Veterinary Medicine (AREA)
• Surgery (AREA)
• Biophysics (AREA)
• General Health & Medical Sciences (AREA)
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• Optics & Photonics (AREA)
• Dermatology (AREA)
• Pain & Pain Management (AREA)
• Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
• Investigating Or Analysing Biological Materials (AREA)

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Citations (5)

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• 2005
  • 2005-02-04 JP JP2006552277A patent/JP2007521121A/ja not_active Withdrawn
  • 2005-02-04 EP EP05712897A patent/EP1761169B1/en not_active Expired - Lifetime
  • 2005-02-04 KR KR1020067015914A patent/KR20060134056A/ko not_active Withdrawn
  • 2005-02-04 BR BRPI0507280-8A patent/BRPI0507280A/pt not_active IP Right Cessation
  • 2005-02-04 CN CNA2005800041443A patent/CN1917810A/zh active Pending
  • 2005-02-04 US US10/590,531 patent/US8398567B2/en active Active
  • 2005-02-04 DE DE602005025214T patent/DE602005025214D1/de not_active Expired - Lifetime
  • 2005-02-04 AT AT05712897T patent/ATE490729T1/de not_active IP Right Cessation
  • 2005-02-04 WO PCT/US2005/003621 patent/WO2005077274A1/en not_active Ceased
  • 2005-02-04 RU RU2006132050/14A patent/RU2006132050A/ru not_active Application Discontinuation
  • 2005-02-04 CA CA002554077A patent/CA2554077A1/en not_active Abandoned
  • 2005-02-04 AU AU2005212296A patent/AU2005212296A1/en not_active Abandoned
• 2006
  • 2006-08-25 NO NO20063798A patent/NO20063798L/no not_active Application Discontinuation

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