Safe lancet injector

• US 5,423,847 A
• Filed: 04/08/1994
• Issued: 06/13/1995
• Est. Priority Date: 09/25/1992
• Status: Expired due to Fees

• Current Assignee: Selfcare Inc. (Johnson & Johnson)
• Original Assignee: AMG Medical Incorporated (AMG Medical USA Inc.)
• Inventors: Oringer, Robert, Strong, Bernard
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US08/225,309
• Time in Patent Office: 431 Days
• Field of Search: 606/181, 606/182, 606/183, 604/117, 604/136, 604/157, 128/770
• US Class Current: 606/182
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150183 Depth adjustment mechanism using end caps mounted at the distal end of the sampling device, i.e. the end-caps are adjustably positioned relative to the piercing device housing for example by rotating or screwing
• CPC Class Codes: A61B 5/150412 Pointed piercing elements, e.g. needles, lancets for piercing the skin blade-like piercing elements A61B5/150442
• CPC Class Codes: A61B 5/150519 Details of construction of hub, i.e. element used to attach the single-ended needle to a piercing device or sampling device
• CPC Class Codes: A61B 5/150549 Protectors removed by rotational movement, e.g. torsion or screwing
• CPC Class Codes: A61B 5/150618 Integrally moulded protectors, e.g. protectors simultaneously moulded together with a further component, e.g. a hub, of the piercing element
• CPC Class Codes: A61B 5/150786 Optical identification systems, e.g. bar codes, colour codes
• CPC Class Codes: A61B 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/15117 comprising biased elements, resilient elements or a spring, e.g. a helical spring, leaf spring, or elastic strap
• CPC Class Codes: A61B 5/1513 comprising linear sliding guides comprising tooth-shaped elements A61B5/15132
• CPC Class Codes: A61B 5/15194 fully automatically retracted, i.e. the retraction does not require a deliberate action by the user, e.g. by terminating the contact with the patient's skin

Abstract

Disclosed is a lancet injector for use with a lancet and an isolating platform to obtain blood samples for diagnostic purposes in a very safe and accurate manner. This lancet injector makes use of two elastomeric bands to push the lancet forwards and to rapidly withdraw the needle from the skin. The lancet injector also has an interlocking mechanism which completely precludes a lancet from being used more than once and thus obviates accidental misuse which could cause cross-contamination between patients. It further has a mechanism which allows the lancet itself to dislodge the platform thereby causing it to automatically jump forward in front of the needle as it collapses and thus to hood the needle and grip the main body of the lancet. It may also be provided with a window in its housing, through which a three color display panel can be viewed. When the lancet injector is ready for loading, a color is displayed, thus indicating that the injector has been emptied and may now be loaded and then cocked. When cocked, another color is displayed, thus indicating that the injector is ready to be fired. After firing, a third color is displayed to give warning signal that the ejector contains a lancet which has been used and should immediately be ejected. The third color display remains locked until the lancet is completely ejected.

Claims

1. A lancet injector for use with a lancet and an isolating platform through which said lancet passes when it is projected by said injector, said lancet injector comprising:

(a) an elongated chassis having;

a longitudinal axis extending between a front end and a rear end;

wherein the front end is open forming a mouth on which said isolating platform can be detachably fixed;

said chassis defining an elongated passage opening into said mouth and comprising a longitudinal front slot and a longitudinal rear slot both opening into said passage, said slots being aligned,

(b) a shaft slidably mounted in a non-rotatable manner within said passage, said shaft having;

a forward end integrally connected to a launching socket in which the lancet to be injected is detachably insertable;

a first abutment at a first distance rearward the launching socket;

a leaf spring at a second distance rearward the first abutment, said leaf spring projecting forwardly outwardly from said shaft and being lockingly engageable within a stop made in the rear slot of the chassis when said shaft is moved rearwardly within the passage; and

a rearward end defining a second abutment;

(c) a first elastomeric band held under slight tension between the second abutment of the shaft and a first elastomeric band attachment point provided on the chassis rearward the mouth;

(d) a lancet ejector slidably mounted in a nonrotatable manner within the passage of the chassis between the mouth and the first abutment of the shaft, said ejector comprising;

a forwardly projecting stem that is slidably movable within the launching socket through a rear opening provided in the launching socket;

an operating knob projecting out of said chassis through an elongated opening provided in the chassis opposite to said front slot; and

a small hook opposite to the knob, said hook being slidably engageable into said front slot of the chassis,

(e) a second elastomeric band held under slight tension between the lancet ejector and a second elastomeric band attachment point provided on the chassis forward the chassis rear end;

(f) a slide member slidably mounted onto the chassis so as to extend longitudinally over the front and rear slots of said chassis when said member is slid forward and rearward, said slide member comprising;

a resilient front tip that is engaged by the hook of the ejector when said ejector moves from a maximum forward position to the rear;

a lower rib that projects downwardly and is slidably engaged into the rear slot of the chassis; and

a rear edge,

(g) an actuating button slidably mounted at the rear end of the chassis so as to be movable along the longitudinal axis of said chassis, said button having a front surface that extends close to the rear edge of the slide member when the shaft is pushed rearwardly within the passage and the leaf spring is lockingly engaged with the stop in the rear slot in front of the lower rib of said slide member, and

(h) a housing enclosing all the above components except for the mouth of the chassis, the knob of the ejector and the actuating button;

whereby, in use, one may carry out the following steps;

i) loading the lancet injector by manually inserting the lancet into the launching socket while pressing on the know of the ejector to deflect the adjacent shaft and thus prevent it from moving rearward;

ii) cocking said injector by pushing rearwards the know of the ejector bearing on the abutment of the shaft so as to push rearwards said shaft until its leaf spring is lockingly engaged with the stop in the rear slot of the chassis, such pushing also causing the slide member to move freely rearward behind the leaf spring engaged with the stop in the rear slot, and the first elastomeric band to tension;

iii) firing said injector by pressing forward onto the actuating button, such pressing causing the slide member to move forward and its lower rib to disengage the spring and thus to release the shaft that is projected forwardly and then rearwardly rapidly under the action of the first and second elastomeric bands, such a movement causing in turn the lancet in the launching socket to move out of the mouth of the chassis past the isolating platform and to penetrate for a very short period of time in the skin of a patient bearing onto said isolating platform; and

iv) ejecting the lancet from said injector by pushing forward the lancet ejector until the lancet falls out of the mouth of the chassis, said ejector and the slide member hooked by the same being then moved back to step (i) under the action of the second elastomeric band.

2. The lancet injector of claim 1, wherein:

the chassis (a) has two opposite sidewalls that extend bilaterally and symmetrically on both sides of the longitudinal front slot and elongated opening of said chassis, each of said sidewalls comprising an angulated slot that extends forwardly at a sight angle towards said front slot said angulated slot being of substantially the same length as said front slot and being provided with a notch at substantially mid-length, that extends in a direction opposite to said elongated opening; and

the lancet ejector (d) comprises two opposite pins that extend transversally to the stem and are slidably engaged into the angulated slots of the chassis, respectively,

whereby;

during the loading step (i), the pressure exerted on the knob causes the pins to engage the notches made in the angulated slots of the chassis and to be locked therein;

during the cocking step (ii), the angulated slots cause the lancet ejector to move away from the front tip of the slide member and thus to avoid any interference with the same until the injector is fired;

during the firing step (iii), the angulated slots cause the lancet ejector to move toward the front tip of the slide member and its hook to engage said front tip rearwardly of the same and to push said slide member forwards; and

during ejecting step (iv), the angulated slots cause the hook of the ejector to deflect the front tip of the slide member and to pass in front of the same, thereby causing said ejector to push back the slide member when it moves rearwards under the action of the second elastomeric band, whereby one must necessarily eject the lancet contained in the injector when said lancet has been used before said injector can be cocked again.

3. The lancet injector of claim 1, wherein the actuating button (g) is slidably mounted into a tubular safety shield attached to the housing at the rear end of the chassis, said safety shield being of such a length that only a meniscus formed on a user'"'"'s fingertip pressed onto said shield, may push the actuating button to such an extent as to cause the slide member to disengage the leaf spring and thus to fire the injector.

4. The lancet injector of claim 3, wherein said safety shield has an internally chamfered rearward edge to assist in raising the meniscus formed on the user'"'"'s fingertip without requiring undue amount of finger pressure.

5. The lancet injector of claim 3, wherein:

the slide member (f) has an upper surface opposite to said lower rib which comprises a front portion of a first color, a medium portion of a second color and a rear section of a third color; and

the housing (h) has a window opening onto the upper surface of the slide member and positioned with respect to said chassis so that;

when the lancet injector is in its loading position in step (i), the second color is displayed through said window;

when the lancet injector is in locked position at the end of step (ii), the first color is displayed through the window; and

when the lancet injector has been fired but the lancet has not been ejected yet in step (iii), the third color is displayed through the window.

6. The lancet injector of claim 5, wherein the housing (h) is made of two clippable half-parts that form together an elongated enclosure in which are located all the other components of the injector, except for the mouth of the chassis the actuating button and the knob of the ejector (d) that slidably extends into an elongated opening provided along one of said half-parts.

7. The lancet injector of claim 3, wherein the housing (h) is made of two clippable half-parts that form together an elongated enclosure in which are located all the other components of the injector, except for the mouth of the chassis, the actuating button and the knob of the ejector (d) that slidably extends into an elongated opening provided along one of said half-parts.

8. The lancet injector of claim 1, wherein:

the slide member (f) has an upper surface opposite to its lower rib, which comprises a front portion of a first color, a medium portion of a second color and a rear section of a third color; and

the housing (h) has a window opening onto the upper surface of the slide member and positioned with respect to said chassis so that;

when the lancet injector is in its loading position in step (i), the second color is displayed through said window;

when the lancet injector is in locked position at the end of step (ii), the first color is displayed through the window; and

when the lancet injector has been fired but the lancet has not been ejected yet in step (iii), the third color is displayed through the window.

9. The lancet injector of claim 8, wherein the housing (h) is made of two clippable half-parts that form together an elongated enclosure in which are located all the other components of the injector, except for the mouth of the chassis, the actuating button and the knob of the ejector (d) that slidably extends into an elongated opening provided along one of said half-parts.

10. The lancet injector of claim 1, wherein the housing (h) is made of two clippable half-parts that form together an elongated enclosure in which are located all the other components of the injector, except for the mouth of the chassis, the actuating button and the knob of the ejector (d) tibet slidably extends into an elongated opening provided along one of said half-parts.

11. The combination of a lancet injector as claimed in any one of claims 1 to 10 with a lancet and an isolating platform through which said lancet passes when it is projected by said injector, wherein:

(j) said lancet comprises;

an elongated body of a given diameter that is snugly insertable into the launching socket of the lancet injector; and

an axial needle embedded into said body, said needle having a sharp end projecting out of said body at a given distance away from one end of the same; and

(k) said isolating platform comprises;

a front plate that extends transversally to the mouth of the chassis when said isolating platform is connected thereto, said plate having a given thickness and a central through-hole of a diameter smaller than the one of the body of the lancet so as to stop said body while allowing the needle of the lancet to pass through the through-hole and to project out of said plate when the injector is fired; and

a fixation sleeve coaxial to the plate and sized to snap onto the mouth of the chassis so as to detachably connect said isolating platform to said mouth;

whereby, by properly selecting the thickness of the plate of the isolating platform, one may adjust the depth of penetration of the sharp end of the needle into the skin of the patient when the lancet injector is fired.

12. The combination of claim 11, wherein:

the one end of the body of the lancet where the sharp end of the needle projects out, has at least one radially extending section that projects from said one end in the same direction as the sharp end of the needle; and

the front plate of the isolating platform has an inner surface, that faces said at lest one radially extending section of the body when the lancet is inserted in the launching socket and the platform is snapped onto the mouth of the ejector, said inner surface having at least two different radial sections that project at different distances away from an average plane parallel to said plate;

whereby proper adjustment of the position of the isolating platform by rotation of the same about the mouth of the lancet injector relative to the lancet when the same is inserted into the launching socket, allows each radially extending section projecting from the one end of the body to be brought into alignment with a preselected radial section of the inner surface of the front plate of the platform and thus to control the depth of penetration of said lancet.

13. The combination of claim 12, wherein:

the elongated body of the lancet has at least one longitudinal rib;

said at least one rib is sized and positioned to fit into a key slot provided in the launching socket so as to lock the lancet in a given position within said launching socket;

a ring defining a supporting shelf is coaxially and rotatably mounted onto the mouth of the chassis; and

the fixation sleeve of the isolating platform is snappable onto the supporting shelf of the ring to detachably connect said platform to the mouth of the injector;

whereby proper rotation of the ring about the longitudinal axis of the injector causes the requested adjustment of the position of the isolating platform relative to the lancet.

14. The combination of claim 13, wherein:

the supporting shelf of the ring is provided with a longitudinal key; and

the fixation sleeve of the isolating platform is in the form of a cylinder that is longitudinally slotted over its full length and is of such a diameter that it can be resiliently opened to snap onto the longitudinal key of the ring.

15. The combination of claim 14, wherein the ring and mouth are provided with marks allowing a user to check the position of the platform relative to the lancet and thus to ascertain the maximum depth of penetration of the sharp end of the needle of the lancet when the injector is fired.

16. The combination of claim 15, wherein the isolating platform also comprises a medium section in the form of an open ring connected by small tabs to the front plate and to the fixation sleeve respectively, said open ring extending in a plane parallel to the front plate and defining with thee same and with the fixation sleeve a set of gripping slots,

whereby, in use, when the lancet is to be ejected, forward motion of said lancet pushed by the stem of the ejector causes the isolating platform to be projected out of the shelf of the ring and to leap ahead of the lancet body and the sharp end of the needle by virtue of the dissipation of the kinetic energy previously stored within the resilient fixation sleeve due to it being stretched over and onto the supporting shelf, the so-projected platform then snapping onto the lancet which remains locked into the gripping slots, thereby obviating accidental needle-sticks and preventing the same lancet to be used more than once, either intentionally or accidentally.