Blood lancet device for and method withdrawing blood for diagnostic purposes

Abstract

Blood lancet device for withdrawing blood for diagnostic purposes, in which with the aid of a lancet drive (3) in a housing (1) a lancet holder (6) with a lancet (34) positioned in it and moveable along a predetermined, straight puncture path is moved until the tip (35) of the lancet emerges from the outlet (84), in order to produce a wound in a body part adjoining the outlet (84). The lancet holder (6) also serves to retract the lancet (34) into a position in which the tip (35) is again positioned within the housing (1). In order to make possible a puncture involving especially little pain, the lancet drive (3) has a rotary/sliding transmission system (4) whose input side (16) is formed by a transmission member which is rotatable about an axis of rotation parallel to the predetermined puncture path. This input-side transmission member (5) of the rotary/sliding transmission system is coupled with the elastic drive element (9) of the lancet drive (3) and converts a torque transmitted to the transmission member (5) into a longitudinal displacement in the direction of the predetermined puncture path, which is transmitted to the lancet holder (6). .Iadd.A method for withdrawing blood for diagnostic purposes using the blood lancet device is also presented..Iaddend.

What is claimed is: 
     
       1. Blood lancet device for withdrawing blood for diagnostic purposes, comprising a lancet (34) comprising a metal needle (166,176) with a tip (35),   a housing (1) with an outlet (84) for the tip (35) of the lancet (34),   a lancet holder (6) located within the housing and connectable to the lancet (34) for holding the lancet (34),   a lancet guide means (15b) located within the housing for guiding the lancet holder (6) for movement on a predetermined puncture path, and   a lancet drive means (3) located within the housing for moving the lancet (34) in a puncturing and retraction direction comprising an elastic drive element (9), a locking device (83) for locking said lancet drive in a fist position in which the elastic drive element (9) is in a tensioned state and for releasing the tension of the elastic drive element (9) to accomplish a puncturing movement during which the lancet holder (6) is moved at high speed along the predetermined puncture path in a puncturing direction until the tip (35) emerges from the outlet (84) to produce a wound in a body part adjoining the outlet (84) and following which the lancet holder (6) is retracted to a position in which the tip of the lancet (34) is positioned within the housing,     the lancet drive (3) further comprising a rotary/sliding transmission system (4) with an input-side transmission member (5) rotatable about an axis of rotation (A) parallel to the predetermined puncture path and coupled to the elastic drive element (9) to be rotated thereby, and with an output-side transmission member connected to the rotatable input-side transmission member (5) for longitudinal displacing the lancet holder (6) in response to rotation of said input-side transmission member (5).   
     
     
       2. Blood lancet device according to claim 1, in which the rotary/sliding transmission system (4) comprising a cam drive mechanism with a recess (39) forming a driver cam (40), a driver pin (52) enagaging said recess such that at least a part of the puncturing and retraction movement is determined by a relative movement between the driver pin (52) and the recess (39), the drive pin (52) travelling along the recess (39). 
     
     
       3. Blood lancet device according to claim 1, in which the input-side transmission member (5) is in the form of a cylindrical sleeve (15) within which is located a piston-shaped part (20) which, during the longitudinal displacement in the direction of the puncture path, slides with a cylindrical outer wall (20b) within the sleeve (15). 
     
     
       4. Blood lancet device according to claim 3, in which the piston-shaped part (20) is connected to the lancet holder (6). 
     
     
       5. Blood lancet device according to claim 1, comprising a tensioning device (137) with an operating element (155) accessible from outside of the housing, said operating element being coupled to the input-side transmission member (5) of the rotary/sliding transmission system in such a way that the elastic drive element (9) can be brought into the tensioned state by rotation of the operating element (155) with respect to the housing (1). 
     
     
       6. Blood lancet device according to claim 5, in which the coupling of the operating element (155) of the tensioning device (137) with the rotary/sliding transmission system (4) has a free-wheeling mode and an elastic return element (140) in order to return the operating element (155) to the starting position after the tensioning of the drive element (9). 
     
     
       7. Blood lancet device according to claim 1, in which the locking device (83) comprising a locking pin (153) firmly connected with the input-side transmission member (5) and in the tensioned state of the lancet drive (3) engages with a stationary locking recess. 
     
     
       8. Blood lancet device according to claim 1, in which the elastic drive element (9) is a spatially wound coiled spring (10) located coaxially to the axis of rotation (A) of the rotary/sliding transmission system (4). 
     
     
       9. Blood lancet device for withdrawing blood for diagnostic purposes, comprising a lancet (34) comprising a metal needle (166, 176) with a tip (35), a plastic body (165) connected to said metal needle (166, 176), and a lancet positioning means (169, 178),   a housing (1) with an outlet (84) for the tip (35) of the lancet (34),   a lancet holder (6) located within the housing and contacting the lancet (34) for holding the lancet (34) and movable within the housing (1) along a predetermined puncture path, and   a lancet drive means (3) located within the housing for moving the lancet in a puncturing direction comprising an elastic drive element (9), a transmission system driven by said elastic drive element to contact and move the lancet positioning means (169, 178) through a precisely defined maximum longitudinal displacement, and   wherein the lancet holder accurately positions the lancet positioning means (169, 178) relative to the lancet drive (3) means such that the puncture depth at which during the puncturing movement tip (35) of the lancet (34, 175) emerges from the outlet (84) varies by no more than at most ±0.15 mm with unchanged setting of the blood lancet device and successive puncturing movements.   
     
     
       10. Blood lancet device according to claim 9 comprising means for adjusting the puncture depth of the lancet (34) within an adjustment range which includes adjustment values of less than 2 mm. 
     
     
       11. Blood lancet device according to claim 10, characterized in that the adjustment range includes adjustment values of less than 1.3 mm. 
     
     
       12. Blood lancet device according to claim 9, comprising means for adjusting the puncture depth of the lancet (34) in steps, the interval between steps being at least 0.2 mm and at most 0.4 mm. 
     
     
       13. Blood lancet device according to claim 9 in which said positioning means (169, 178) is accurately located with respect to the needle (166, 176) of the lancet (34) and a stop (170) on the lancet drive means (3), and wherein the lancet (34, 175) is held in the lancet holder (6) in such a way that the positioning means (169) is elastically pressed against the stop (170).   
     
     
       14. Blood lancet device according to claim 9 in which the puncture depth varies at most by ±0.1 mm. 
     
     
       15. Blood lancet device according to claim 14 in which said driver output member (40) is configured to have a cam segment 42 with an apex 43 which precisely defines the maximum longitudinal displacement of the needle (166, 176). 
     
     
       16. Blood lancet device according to claim 9 in which the puncture depth varies at most by ±0.05 mm. 
     
     
       17. Blood lancet device for withdrawing blood for diagnostic purposes comprising a lancet (34) comprising a metal needle (166, 176) with a tip (35) and a plastic body (165),   a lancet holder (6) for holding the lancet (34),   a lancet drive means (3) for driving the lancet needle (166, 176) along a predetermined straight path, the driving means comprising a driver input member rotatable about an axis parallel to the straight path, a driver output member connected to the lancet and the driver input member for converting the rotation of the driver input into longitudinal movement of the lancet along said straight path, and     means for accurately positioning the metal needle (166, 176) of the lancet (34) relative to the driving means, thereby accurately to control the puncture depth of the tip (35), the positioning means comprising a positioning means surface (169) on the needle (166, 176), a stop (170) on the lancet holder (6) for abutting the positioning means surface (169), and elastic means for pressing the positioning means surface (169) against the stop (170). .Iadd.   
     
     
       18.  A method for withdrawing blood for diagnostic purposes by puncturing a patient using the blood lancet device of claim 1, said method comprising: inserting the lancet into the lancet holder with a lancet positioning means surface on the lancet engaging a stop of the lancet holder which is connected to the output-side transmission member on the lancet drive means and wherein there is an elastic means for pressing the lancet positioning means surface against the stop;   holding the blood lancet device against the skin of a patient; and   actuating the lancet drive means to drive the lancet along the predetermined puncture path through a precisely defined longitudinal movement, wherein the needle tip will emerge from the blood lancet device and be driven into the skin of the patient..Iaddend..Iadd.   
     
     
       19.  A method according to claim 18, wherein the puncture depth can be varied without changing the precisely defined longitudinal movement by changing the relative position of the fully inserted needle tip with respect to the patient's skin..Iaddend..Iadd.20. A method according to claim 18, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.15 mm with unchanged setting of the puncture depth..Iaddend..Iadd.21. A method according to claim 20, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.1 mm with unchanged setting of the puncture depth..Iaddend..Iadd.22. A method according to claim 21, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.05 mm with unchanged setting of the puncture depth..Iaddend..Iadd.23. A method according to claim 18, wherein the puncture depth can be adjusted in an adjustment range which includes values of the puncture depth below 2 mm..Iaddend..Iadd.24. A method according to claim 23, wherein the puncture depth can be adjusted in an adjustment range which includes values of the puncture depth below 1.3 
     
     
        mm..Iaddend..Iadd.25.  A method for withdrawing blood for diagnostic purposes by puncturing a patient using the blood lancet device of claim 17, said method comprising: inserting the lancet into the lancet holder with the lancet positioning means surface engaging the stop on the lancet and wherein the elastic means presses the lancet positioning means surface against the stop;   holding the blood lancet device against the skin of a patient; and   actuating the lancet drive means to drive the lancet along the predetermined puncture path through a precisely defined longitudinal movement, wherein the needle tip will emerge from the blood lancet device and be driven into the skin of the patient..Iaddend..Iadd.26. A method according to claim 25, wherein the puncture depth can be varied without changing the precisely defined longitudinal movement by changing the relative position of the fully inserted needle tip with respect to the patient's skin..Iaddend..Iadd.27. A method according to claim 25, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.15 mm with unchanged setting of the puncture depth..Iaddend..Iadd.28. A method according to claim 27, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.1 mm with unchanged setting of the puncture   
     
     
        depth..Iaddend..Iadd.9.  A method according to claim 28, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.05 mm with unchanged setting of the puncture depth..Iaddend..Iadd.30. A method according to claim 25, wherein the puncture depth can be adjusted in an adjustment range which includes values of the puncture depth below 2 mm..Iaddend..Iadd.31. A method according to claim 30, wherein the puncture depth can be adjusted in an adjustment range which includes values of the puncture depth below 1.3 
     
     
        mm..Iaddend..Iadd.32.  A method for withdrawing blood for diagnostic purposes by puncturing the skin of a patient utilizing a blood sampling system comprising a blood withdrawal instrument and disposable lancets wherein the blood withdrawal instrument comprises a housing with a needle outlet, a pressure surface surrounding the needle outlet, a drive means and a lancet holder for exchangeably holding the disposable lancets and wherein the disposable lancets comprise a metal needle embedded in a plastic body with the needle having a needle tip extending outwardly from a first end of the plastic body and a flat end accessible adjacent an opposite end of the plastic body, said method comprising: inserting the disposable lancet, flat needle end forward, into the blood withdrawal instrument to a position in which the flat end of the needle contacts a stop on the lancet holder and in which the lancet is accurately positioned relative to the lancet holder by being pressed against the stop by elastic means;   placing the pressure surface of the blood withdrawal instrument against the skin of the patient; and   actuating the lancet drive means to have the lancet drive means move the lancet holder and the disposable lancet held therein along a predetermined puncture path through a precisely defined longitudinal displacement wherein the tip of the disposable lancet emerges from the needle outlet of the blood withdrawal instrument and past the pressure surface surrounding the outlet into the patients' skin..Iaddend..Iadd.33. A method according to claim 32 wherein the movement of the lancet holder driven by the lancet drive means and the positioning of the disposable lancet needle tip are so precise, that the puncture depth, the distance the lancet tip emerges past the pressure surface surrounding the outlet, varies by no more than at most 0.15 mm with unchanged setting of the blood withdrawal instrument and successive puncturing movements in which different lancets are inserted in the lancet holder..Iaddend..Iadd.34. A method according to claim 33, wherein the puncture depth varies by no more than at most 0.1 mm..Iaddend..Iadd.35. A method according to claim 33, wherein the puncture depth varies by no more than at most 0.05 mm..Iaddend..Iadd.36. A method according to claim 33, wherein the puncture depth of the tip of the needle of the disposable lancet can be adjusted, without a change in the defined longitudinal displacement, by changing the relative position of the pressure surface and the lancet holder..Iaddend..Iadd.37. A method according to claim 36, wherein the puncture depth may be adjusted in an adjustment range including values below 2 mm..Iaddend..Iadd.38. A method according to claim 37, wherein the adjustment range extends below 1.3 mm..Iaddend..Iadd.39. A method according to claim 32, wherein the pressing of the disposable lancet is obtained by a pair of tongue lugs extending from the lancet holder that penetrate into recesses in the plastic body of the disposable lancet for gripping the plastic body and urging the flat rear end of the needle of the disposable lancet against the stop of the lancet holder..Iaddend..Iadd.40. A method according to claim 32, wherein rotation of the disposal lancet during operation of the blood withdrawal instrument is avoided by mutually cooperating non-round shapes of an interior space of the blood withdrawal instrument and the plastic body of the disposable lancet..Iaddend..Iadd.41. The blood lancet device according to claim 9 wherein the lancet drive transmission system maintains contact with the lancet, after the movement to the defined maximum longitudinal displacement, to retract the lancet from the defined maximum displacement reversely along the puncturing direction..Iaddend..Iadd.42. The blood lancet device according to claim 9 wherein the lancet drive transmission system includes a rotatable input member and a driver output member; wherein the driver output member contacts and moves the lancet; and wherein the driver output member engages the rotatable input member to be longitudinally moved in a straight path to provide the maximum displacement in response to rotation of the rotatable input member..Iaddend..Iadd.43. The blood lancet device of claim 9 wherein the lancet holder is provided with elastic biasing means to press the lancet positioning means against an output member of the transmission system..Iaddend..Iadd.44. The blood lancet device of claim 43 wherein the lancet plastic body is provided with a plurality of recesses and wherein the lancet holder is provided with a plurality of tongue lugs that extend into the recesses to provide the biasing means to press the lancet positioning means..Iaddend..Iadd.45. The blood lancet device of claim 9 wherein the positioning means includes a surface on the lancet, which surface is in contact with and abuts an output member of the transmission system inside the lancet holder to provide the drive from the elastic drive element that moves the lancet..Iaddend..Iadd.46. The blood lancet device according to claim 9 wherein the housing and the plastic body of the lancet have mutual cooperating and contacting non-round shapes to prevent rotation of the lancet with respect to the housing during the puncturing movement of the lancet tip..Iaddend..Iadd.47. A method for withdrawing blood for diagnostic purposes by puncturing a patient using the blood lancet device of claim 43, said method comprising:   inserting the lancet into the lancet holder with the lancet positioning means engaging the output member of the transmission means and wherein the elastic biasing means presses the lancet positioning means surface against the output member;   holding the blood lancet device against the skin of a patient; and   actuating the lancet drive means to drive the lancet in the puncture direction through the precisely defined maximum longitudinal displacement, wherein the needle tip will emerge from the blood lancet device and be   
     
     
        driven into the skin of the patient..Iaddend..Iadd.48.  A method according to claim 47, wherein the puncture depth can be varied without changing the precisely defined longitudinal displacement by changing the relative position of the fully inserted needle tip with respect to the patient's skin..Iaddend..Iadd.49. A method according to claim 47, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.15 mm with unchanged setting of the puncture depth..Iaddend..Iadd.50. A method according to claim 49, wherein the puncture depth of the needle tip into the patient varies by no more than at most 0.1 mm with unchanged setting of the puncture depth..Iaddend..Iadd.51. A method according to claim 50, wherein the puncture depth of the needle tip into the patient varies by no more then at most 0.05 mm with unchanged setting of the puncture depth..Iaddend..Iadd.52. A method according to claim 47, wherein the puncture depth can be adjusted in an adjustment range which includes values of puncture depth below 2 mm..Iaddend..Iadd.53. A method according to claim 50, wherein the puncture depth can be adjusted in an adjustment range which includes values of the puncture depth below 1.3 mm..Iaddend..Iadd.54. The blood lancet device of claim 9 wherein the lancet drive means provides a positive drive connection for the lancet to move the lancet along its predetermined path through a first movement in the puncturing direction and a subsequent stopping and retraction of the lancet back into the housing..Iaddend..Iadd.55. The blood lancet device of claim 17 wherein the lancet drive means provides a positive drive connection for the lancet to move the lancet along its predetermined path through a first movement in the puncturing direction and a subsequent stopping and retraction of the lancet back into the housing..Iaddend..Iadd.56. The method according to claim 18 wherein the lancet drive means provides a positive drive connection for the lancet to move the lancet along its predetermined path through a first movement in the puncturing direction and a subsequent stopping and retraction of the lancet back into the housing..Iaddend..Iadd.57. The method according to claim 25 wherein the lancet driver output member connection positively drives the lancet along its predetermined straight path in a first puncturing direction and subsequently stops and then retracts the lancet..Iaddend..Iadd.58. The method according to claim 32 wherein the lancet drive means also subsequently stops movement of the lancet holder and then retracts the lancet holder to withdraw..Iaddend.