Lancing device

[0001] The present invention relates to lancet devices, and in particular, but not exclusively, to such devices intended for single use. In many conventional lancet devices, such as Unistik® lancet devices, the pointed lancet body of the elongated form is held in the housing and energized by a compression spring. The sharp tip is typically provided by the pointed end of the lancet needle around which the lancet body is formed. After actuation, the lancet body performs a longitudinal extension and retraction motion to provide a linear puncturing action. The linear puncturing effect allows the use of a linearly acting spring and affects the high reliability of the device. Longitudinal movement and the resulting simplicity of operation lead to a low number of components, which facilitates production and assembly. Also, the low number of components means less cumulative tolerance, which is important when dimensional tolerance is critical to ensure that lancet penetration is predictable and is neither too deep nor too shallow.

[0002] In some situations, when collecting a drop of blood from a newborn's heel, or when a larger volume of blood is required, a different puncture effect may be needed. Instead of a linear puncturing action, a cutting action may be preferred to cut the capillaries. There are, therefore, many designs of puncture devices that use the blade instead of the needle and which generally rotate the blade to cause the blade to move through the opening in the puncture device housing to cut the skin to form a short slit or a short cut in the skin through which blood can flow into skin surface. In the latter type of devices, the construction is generally more complex, using the blade instead of the needle, as well as typically using an articulated system driven by a torsion spring to cause the blade to follow the arc-shaped path.

[0003] US4157086 discloses a system in which a torsion spring provides a rotary drive for a mandrel that causes predetermined and repeatable blade movement.

[0004] US5527333 discloses a system in which a user presses a trigger that extends an initially unstretched spring to stretch against its force to slide the blade out of the housing. Accordingly, the blade is moved forward by the user pressing the trigger, and not by releasing the tension energy stored in the spring.

[0005] US2823677 discloses a device driven by a torsion spring.

[0006] US2007 / 0095178 discloses a device in which the blade is connected to a switching connector via a transverse spring. The device is started by pressing the draining cap, which pushes and then releases the connector.

[0007] US5571132 discloses a system in which the blade is driven forward along a predetermined path by a user exerting an input force rather than releasing stress energy.

[0008] US4643189 discloses a system in which a rotatably or transversely operating spring drives a blade to make an incision.

[0009] US 5 571 132 A discloses a device for producing blood drops, comprising a housing with a cam channel, a blade assembly with cam channel pushers and a manual trigger mechanism. The lower end of the cam channel is inclined to provide articulation of the lancet tip when the trigger mechanism is fully depressed by the user.

[0010] We have designed a device that implements the cutting action of the tool with a cutting edge and which preferably uses a longitudinally directed spring that is under tension to exert a force on the lancet that is directed forward to provide its drive to make the incision, thereby taking advantage of the many advantages of said devices first. Another object of the invention is to provide a device that obtains cutting action by means of a modified needle profile.

[0011] Accordingly, in a first aspect, the invention provides a lancet device comprising:

The lancet body in an elongated form and comprising a sharp tip at its front end;

a longitudinally operating drive spring for pushing the lancet body forward;

a housing receiving the lancet body and comprising an opening at its front end through which the sharp tip of the lancet body protrudes in use when the device is activated;

wherein said device comprises means for controlling movement of the lancet body to provide lateral movement of the tip as it protrudes from said hole.

[0012] In another aspect, the invention provides a lancet device comprising:

a housing with a puncture hole at the front end;

a lancet comprising a lancet body and a lancet tip at the front end;

a longitudinally operating drive spring for pushing the lancet forward from the rear to a taut position in which the tip is inside the housing;

trigger that can be operated to hold said lancet in its rear position against the spring pushing action, but movable to release said lancet for forward movement when said drive spring moves said lancet forward to cause said tip to temporarily slide out of said housing and then tip return to the housing and interacting surfaces associated with said housing and said lancet, respectively, for causing said tip to deflect as said lancet moves forward, whereby said tip moves laterally as it extends through said puncture hole.

[0013] It should be noted that in this device, in the early stages of the movement of preferred embodiments, the significant, if not the main, component of the movement of the lancet body is the longitudinal component, in a similar way as in linear operating devices, thus allowing the use of at least some from the design principles of these earlier devices.

[0014] As in the previous linear devices cited, the puncturing force is preferably provided by a linear or longitudinally acting spring that is configured to release stress energy to deliver the lancet body thrust forward. The thrust can be provided by a tension or compression spring, and any suitable spring configuration can be used.

[0015] The means for controlling movement of the lancet body to cause lateral movement of the tip may take many forms. For example, they may include cooperating control surfaces on the lancet body and the housing, respectively. References to the housing include other components attached or otherwise associated with the housing, such as inserts or other components. Cooperating control surfaces may include a cam surface on the housing and a cam follower on the lancet body. Preferably, the lancet body includes a front and rear cam follower, each of which interacts with the cam surface for at least a portion of the stroke of the lancet body after actuation.

[0016] The cam surface can be profiled in a variety of ways to achieve lateral movement of the lancet tip when exposed. Thus, the surface of the cam may generally include an upstream portion and a curved or sloping downstream portion adapted to cause said lateral movement when the tip is exposed. The upstream portion is preferably generally straight and parallel to the longitudinal axis of the device. The later part may preferably be arched or otherwise curved. The upstream part can go directly to the downstream part, but in a preferred arrangement an intermediate part is provided that connects to the upstream and downstream parts. The intermediate part is preferably inclined with respect to the longitudinal axis, so that the cam surface deflects first in one direction in the intermediate part and then in the reverse direction in the later part, so that accordingly the tip of the lancet body moves laterally in one direction as it moves forward in the lancet housing against rapid movement in the opposite, transverse direction when the tip is exposed through an opening in the housing.

[0017] The earlier, intermediate and later parts may contain one, in a manner

EP 2806796 B1 a continuous curved portion or one or more straight portions oblique to each other. Parts may be continuous or discontinuous. Alternatively, there may be a surface associated with the lancet and a surface associated with the body that interact only in the direction of the end of the forward stroke of the lancet for lateral tip deviation.

[0018] Preferably, the lancet device is designed such that when the drive spring is actuated, it pushes the lancet body forward to cause the tip to slide out through the housing opening and then retract back into the housing when the spring rebounds, retracting the lancet body with it and thus ensuring that the device is secure. In such cases, the later part is preferably generally U-shaped with one U-arm connecting to the earlier part or intermediate part, depending on the circumstances, whereby when the device is activated, the front cam pusher is driven down along one arm to the base U because the lancet body is driven forward by the spring and then backwards along the second U arm as the lancet body is retracted by the reflection of the spring.

[0019] As before, the parts in the outward and reverse directions U may be continuous or spaced apart. In addition to the U-shape, the path can simply be a return arm that captures the cam follower when the lancet moves backwards after reflection, temporarily extending the tip. Preferably, the other end of the U-shaped lateral arm, or the return arm is blind or has a associated abutment surface on which, upon actuation, the lancet body is blocked from further rearward movement. This ensures irreversible operation, thus preventing attempts to arm the device by pushing the lancet body backwards. Alternatively, the cooperating surfaces on or associated with the lancet body may define predetermined outward and return paths for the front of the lancet body because the drive spring initially drives the lancet body forward and then rebounds.

[0020] The drive spring may be a compression or tension spring and the device may be equipped with a preloaded spring, or the user may have to initially tension the spring before use. In preferred embodiments, the spring tension energy is the only active force

EP 2806796 B1 acting on the lancet when activated.

[0021] The lancet body may be rigid along its length, but, in particular where an elongated incision arc is required, the lancet body may include articulated front and rear portions, the rear portion being held to follow a generally longitudinal path down the housing during when the front part is articulated or elastically attached to the rear part and is equipped with a guide pin that follows a contoured path. That is, in use, the lancet tip follows an arc with a smaller radius because the radius is defined by the distance between the tip and the hinge point, and not by the distance between the front and rear guide pins of the illustrated embodiment.

[0022] Preferably, the lancet body includes a further guide element moving in a slot or groove in the housing to guide its movement.

[0023] The sharp lancet tip can take many forms. It can be a cutting edge forming part of the lancet body or it can be a cutting edge on the insert. Preferably, the sharp tip of the lancet body is provided by the sharp front end of the lancet needle forming part of the lancet body e.g. in such a way that the body is formed around the needle. The needle is preferably cylindrical due to two mechanically machined surfaces defining the cutting edge of its front end. The machined surfaces are preferably flat, provided by grinding or similar operations. The angle between the face surfaces defining the cutting edge is preferably between 20 ° and 40 °. The cutting edge is preferably linear and preferably extends at an angle of 30^about up to 80^about relative to the longitudinal axis of the needle. This ensures that the edge of the knife is applied to the skin for effective cutting movement.

[0024] To facilitate the production and assembly of the device, the lancet needle is preferably provided with a mark backward from the tip. The marker can be used to ensure that the device moves in one plane during the cutting movement. It should be understood that it is important to provide such angular alignment and that a generally cylindrical needle will otherwise not have means for angular alignment beyond the ground face at the tip of the needle. The mark may take many forms but is preferably a flat surface formed around the periphery of the rear end portion e.g. by removing

EP 2806796 B1 sector shape by grinding.

[0025] In some embodiments, the invention may include a lancet needle for transverse movement thereof to provide an incision in use, the needle being in the cylindrical form and having two machined surfaces defining the cutting edge at its front end and being provided with a mark distant to back from the front end.

[0026] In other embodiments, the invention may include a lancet device comprising:

the lancet body in an elongated form and having a sharp tip at its front end;

a drive spring for imposing a generally longitudinal movement of said lancet body from a tensioned position toward a released position and then for reversing said lancet;

a housing receiving said lancet body and comprising an opening at its front end through which the sharp end of the lancet body protrudes temporarily, in use when the device is activated;

wherein said device comprises means for preventing re-tensioning to prevent the lancet from returning to the tensioned position after it has been actuated, said counteracting means comprises a path with a return portion provided in or on said lancet housing or body and a guide element in the path provided on the remaining element, in use when the lancet reaches its extreme forward position and when the lancet retracts, the guide element in the path moves along the return portion and further retraction of the lancet is limited by the interaction of the path and the guide element in the path.

[0027] Although the invention has been described above, it extends to any novel combination or sub-combination of the elements set out above.

[0028] The invention may be implemented in a number of ways and, by way of example only, one specific embodiment will now be described in detail with reference to the accompanying drawings, in which:

EP 2806796 B1

Figures 1, 2 and 3 respectively show a perspective, rear and side view of an embodiment of the lancet device according to the present invention; Figure 4 shows a cross section of the device;

Figures 5 (a) and (b) are perspective views of the lancet body coupled to the lower half of the housing, with the upper half of the housing removed, seen from different angles;

Figures 6 (a) to (d) show respectively a top and bottom perspective view and a top view and bottom view of the lancet used in the embodiment of Figures 1 to 5;

Figures 7 (a) to (c) show side, bottom and perspective views of the lancet needle used in the embodiment of Figures 1 to 6;

Figure 8 shows a cross-section of the lancet;

Figures 9 (a) to (f) are respective views of the device with the upper casing removed, showing the sequence of moving the lancet as it slides down the casing, protrudes and moves sideways to make the incision, and then retracts when the device is started;

Figures 10 (a) to (f) are views similar to those of Figures 9 (a) to (f) but a modified embodiment of the device with a lancet body having a resilient lateral projection;

Figure 11 is a view of the lancet body with the elastic side tab used in the embodiment of Figures 10 (a) to (f);

Figure 12 is a view of the modification of the lancet guiding path in the above embodiments to provide a snap action, non-reversible;

Figure 13 is a schematic view of an embodiment of a lancet device with a linear puncturing effect but cooperating with a J-shaped path to prevent re-tensioning after use;

Figures 14 (a) to (d) are views of another embodiment of a puncture device with a linear puncturing effect but cooperating with a branched profiled path to prevent re-tensioning after use; Figures 15 (a) to (e) show views of another embodiment of the device

EP 2806796 B1 for puncturing with a linear puncturing effect cooperating with the J-shaped path to prevent re-tensioning after use;

Figures 16 (a) to (d) show views of another embodiment of a puncture device with a linear puncturing effect cooperating with the J-shaped path to prevent re-tensioning after use; and

Figure 17 is a schematic view of an articulated lancet for use in the above embodiments.

[0029] Referring to the Figures, examples are shown of a lancet device comprising a housing 10, including an upper and lower portion 10 respectively¹ and 10² and surrounding lancet 12, consisting of the lancet body 14 formed around the sharpened lancet needle 16, as shown in Figures 6 to 8 below. The lancet 12 is held in a retracted position by a latch 17 at the front end of the trigger lever 18, mounted as a swingarm in the housing 10, by means of a flexible hinge 19 and lifting the trigger cushion 20 at its rear end (looking at Figure 4). It should be understood that the cutting edge provided by the needle may be interchangeably any other suitable cutting edge formed on the insert or directly as an integral part of the lancet body. The element on which the cutting edge is formed may be of any suitable material including metals and various plastics.

[0030] The wall of the front end of the housing 10 is provided with a longitudinal needle slot 22 through which the lancet needle 16 projects in use. Around the lancet slot 22 on the front wall are ten protrusions 24 that, when the device is applied to the skin before actuation, produce a distraction or confusion effect to reduce pain when the device is actuated. Lancet 12 is pushed forward by a spring 26 acting between the rear end of the lancet and the inner end wall of housing 10, as seen in Figure 4. In other views, the spring has been removed for clarity. The device can be delivered in a tensioned state, with the lancet held in the position of Figure 4, against spring force, by means of a trigger latch, or the device can be delivered in an unrestrained position, allowing the user to tension the device by pushing the lancet backward, against the spring force until it clicks into place behind the trigger latch.

[0031] In many conventional devices, the lancet 12 performs a pure longitudinal movement when it is activated to provide a puncture site in the puncturing operation. In the embodiments disclosed herein, the movement of the lancet 12 is controlled such that the lancet tip performs a lateral movement when it projects through the lancet slit 22 in the housing to thereby make a short incision in the body instead of a stab wound. To this end, the lancet 12 is equipped with a front and rear guide pin 28, 30, respectively, on its underside (see Figure 6 (b)). These guide pins move in a profiled path 32 or groove formed in the inner wall of the lower housing part 102, looking at Figures 5 and

9. The track 32 has a generally cranked J shape, consisting of a rear longitudinal section 32¹coinciding with the longitudinal axis of the device and the inclined part 32²which swivels to one side of the device (right, looking at Figure 9 (a)) and ο

end of part 32³ U-shaped. The free end of the U-shaped part is blind. The guide pins 28, 30 slide along the path 32, while the lancet 12 moves generally longitudinally down the body under the action of the drive spring 26. The system imposes a gentle angular movement to deflect the front end of the lancet in one direction when it moves from the position shown in Figure 9 (a) to the position shown in Figure 9 (b) before imposing the opposite sharp angular movement in the opposite direction, looking at Figures 9 (c ) to 9 (e) when the tip of the lancet needle 16 is extended through the lancet slot.

[0032] The drive spring 26 is designed such that, when activated, it initially passes out of rest position, driving the lancet to the position shown in Figure 9 (d), before the reflection pulling the lancet out of its apogee of movement and retracting it safely into the housing as shown in Figure 9 (f). In the position shown in Figure 9 (f) the engagement of the front pin 28 with the blind end 33 of the U-shaped part ensures that the device cannot be re-tensioned by applying backward pressure on the lancet through the lancet slot. The pin 28 may be flattened to ensure contact of the surface with the surface with the flat surface at the blind end 33 of the path.

[0033] Embodiments of the present invention ensure that the lancet needle is a cutting edge for making an incision when the lancet needle tip extends from the lancet slot. The needle tip 16 of the lancet is equipped with two facets 34, 36 or end faces that define the cutting edge. Planes

The faces defined by the faces intersect at an angle of typically 30 ° when looking at Figure 7 (a), although other angles may be selected to suit the application. In addition, the cutting edge (i.e. the line of intersection of these two planes) is inclined relative to the longitudinal axis, so that the edge acts as a knife. The edge may typically lie at an angle of 60 ° to the longitudinal axis of the needle, as seen in Figure 7 (b).

[0034] The production of the lancet needle 16 requires thorough grinding of the needle in the device to provide flattening 34 and 36. During production, typically, the needle lot is held in the device and the two face surfaces are ground on the needles. It is important to ensure that the needles are correctly positioned during installation in the puncture device after manufacture, so that the cutting edge moves in one plane as the needle tip extends from the housing lancet slot and moves laterally. Any angular position deviations can negatively affect the operation of the device, leading to ineffective and painful cutting. In the disclosed embodiments, the lancet needles 16 are thus initially provided with a mark 40, which is located at the rear end of the needle. The mark 40 can be used to align the needles before grinding and thus ensure that the ground faces are in the same position relative to the ground flattened 40. The flattening 40 is used to position the needle in a unique correct angular orientation in the forming tool (not shown) which is used to form the lancet body 14 around the lancet needle 16. The needle 16 can thus initially be positioned in the mold by three pins, two of which protrude from the mold after forming the lancet body from the holes 42 and 44, looking at Figure 8, and the third pin contacts the flattening of the marker 40 and stops the pin from moving to back during the plastic molding process and then emerges from the mold leaving the recess 46 visible in Fig. 8.

[0035] Referring now in more detail to Figure 6, the lancet body includes at its rear end a bulbous head 48 holding the spring, which is tapered at 50 before joining the generally rectangular flange 52 on which the rear pin 30 is formed. A pair of side the projections 54 protrude on each side of the collar and move in the respective guide slots 56 in the side wall of the housing 10 (as can be seen in Figures 1 and 3). Leading performances 54

EP 2806796 B1 stabilizes the movement of the rear end of the lancet 12 when its front end performs the lateral movements cited above. The front guide pin 28 is integrally formed at the rear of the front edge of the generally trapezoidal formation 58 at the front end of the body, the front edge acting as the latch face 60 for the latch 17.

[0036] As shown in Figures 10 and 11, to assist the movement of the lancet in ο

lateral direction when the front peg moves around the later part 32³ U-shaped path 32, the lancet body may be provided with a resilient tab 62, which is compressed when the front end of the lancet moves off the axis from the position of Figures 9 (a) to 9 (c) and then expands to push the front end in the opposite direction to assist the front pin 28 around the curved area of ​​the U-shaped part.

[0037] Referring to Figure 12, if desired, a back protector may be provided that blocks the lancet from moving forward from the actuated position (positions of Figures 9 (f) and 10 (f)). This may be the interaction of the lancet body and the housing. For example, as shown in Figure 12, the path 32 may include a ramp or portion 64 of a spring latch, beyond which the front pin 28 latches as it approaches the blind end 33 ο

later part 32³so that after the puncturing operation is completed, the lancet is blocked from forward movement.

[0038] Referring to Figure 13, in a further embodiment, the back safety device disclosed above may be embedded in a linearly moving puncture device to prevent re-tensioning. Thus, the lancet body 14, limited to only generally linear motion, may be provided with a pivoting plate 66 articulated to the lancet body at its midpoint and lifting a front pin 68, which moves in a J-shaped path 32 containing the return portion from retaining surface at the end. There may also be a rear pin on the plate as shown. The pin or pins on the plate moving in the J-profile path prevent re-tensioning, as in the above embodiments, while the respective guide pins 70 on the lancet body move in the linear guide groove 72, limiting its movement to linear.

[0039] Instead of a pin or pins on a separate element, one pin can be provided on the arm integral with the lancet body and capable of elastic bending movement. In such a device, as in operation in Figures 9 (a) to 9 (c), the drive spring extends excessively and then retracts so that the lancet tip temporarily slides out of the housing to puncture the puncture site and then returns to casing, but in this arrangement the movement of the lancet body is linear and it is the pin of the hinged plate that follows the J-shaped profile and after puncture prevents re-tensioning of the lancet.

[0040] Referring now to Figures 14 (a) to (d), another embodiment of a lancet device is shown in which the lancet housing 110, with the lancet opening 122 at its front end, surrounds the lancet 112, with the tip 116 at its front end. The lancet is limited to linearly moving within the housing by means of pins 170 protruding from the lancet body which move in a linear groove 172 provided on the inner side wall of the housing. The lancet is pushed forward by the interacting longitudinal helical compression spring 126 and held in a tensioned position as shown in Figure 14 (a) by means of the trigger assembly generally designated 120. The articulated side mounted lancet body opposite the studs 170 has a pivotable plate 166 with two ends, having a pin rotatably received in the pocket of the lancet body. The pivoting plate includes two protruding pins 168¹ and 168²that move in the profiled branched path 132 in the housing wall. Path 132 includes a main portion parallel to the linear guide groove 172, but its front end curves to one side to provide an overall J-shape. At some point along the main stem portion, there is also a return loop or branch portion to the other side.

In operation, after releasing trigger 120, the lancet body is fired forward from the tension position shown in Figure 14 (a) and (c), driven by the extending compression spring 126 until the needle tip 116 temporarily protrudes through the puncture opening 122 for puncturing the skin. As the lancet approaches its extreme front position, the front pin 168¹ enters the curvature J and thus begins to deflect the deflectable plate 166 counterclockwise, looking at Figures 14 (c) and (d), so that the pins 168¹ and 168² they enter into opposing curved parts facing away from each other

EP 2806796 B1 is provided in path 132. This is continued until the spring 126, after rebound, begins to shorten, when it pulls the lancet 122 back and thus the pins 168¹ and 168² pass back to the blind ends of the branch paths 132 when the tip is retracted in the housing. In this way, further backward movement of the lancet is prevented and therefore cannot be re-tensioned.

[0042] Referring now to the system of Figures 15 (a) to (e), it works on very similar principles as shown in Figure 14, except that the pivoting plate has one arm and lifts one pin 268, and the path 232 has one branch and therefore has a simple J-shape. The pivoting plate 266 and the pin 268 operate in the same way as the front end of the arm 168 etc. in the Figure will therefore not be described in detail again. Equivalent components in Figures 15 (a) to (e) have the same reference numbers, but increased by 100.

[0043] Referring now to the embodiment of Figures 16 (a) to (d), it is closely based on the arrangement shown in Figure 15, but uses an integral flexible arm or flexible hinge to allow the arm 366 to bend or deflect relative to the lancet body 312 in an analogous manner to the articulated arm 266 and the lancet 212 in the arrangement of Figure 15. As in Figure 15, the pin 368 that protrudes from the arm 366 moves in path J-shaped 332. The other components of the device of Figures 16 (a) to (d) are similar to the components of Figures (a) to (e) and have equivalent references to their equivalents, increased by 100.

[0044] In each of the arrangements of Figures 14 to 16, after actuation of the lancet, the lancet body is fired forward, temporarily extending the tip and then bounces, thereby pulling the pin or projection to the blind end of the J-shaped path and preventing re-tensioning the device.

[0045] Of course, it should be understood that the above arrangements can be inverted, so that one or more paths can be located on the lancet body, and one or more pins can be located on the housing, or on a flexible or articulated connector associated with the housing.

[0046] As noted above, the lancet body may be rigid along its length, but in particular where an elongated incision arc is required, the lancet body may include articulated front and rear portions, the portion

The rear part is limited to move in a generally longitudinal path down the housing, and the front part is articulated or elastically attached to the back part and is equipped with a guide pin that follows the profiled path. An example of such an articulated lancet is shown in Figure 17. As can be seen, the lancet body 414 is tapered in the front area, behind the tip 416, to provide a flexible connector that allows the tip area to bend or deflect relative to the rest of the body. The body is equipped with pins 430 that move in a straight portion of the steered groove when the lancet moves to its extreme forward position and is reflected so that the main body moves in a straight line back and forth. The pin 428 in the tip region initially moves in the straight part, but then is inserted into the arch part to ensure that the tip will follow the arc path as it protrudes from the housing.

[0047] In the various embodiments described above, the path has been described as being J-shaped. Of course, it should be understood that in some applications only a curved end can be used, with the lancet restricted to or otherwise oriented in general linear motion, in some other way, not requiring J's longer arm. In addition, the path may simply be at an angle to the longitudinal axis to provide lateral bending, with a linear, curved and continuous or broken path.

EP 2806796 B1