MXPA06008844A - Dampening and retraction mechanism for a lancing device - Google Patents

Abstract

A lancing device (10) is disclosed that includes a main housing (12) having an internal surface enclosing a portion of a lancing mechanism. The lancing mechanism includes a lancet holder (36) attached to a shaft (38) and a drive spring (42) surrounding a portion of the shaft (38). The lancing device (10) also includes a movable housing (14) adjacent the main housing(12). The moveable housing (14) has an internal surface enclosing a portion of the shaft (38) of the lancing mechanism. The enclosed portion of the shaft (38) has a retainer (40) and a secondary spring(46) surrounding at least a section of the shaft (38). The secondary spring (46) is adapted to move the movable housing (14) from a cocking position to a resting position. The secondary spring (46) is further adapted to move the lancing mechanism from a puncture position to a resting position.

Description

ili Publishcd: - with intemational s' earch report For two-leller codes and other abbreviations. refer to the. "Guidance Notes on Codes and Abbrevialions" appearing at lhe begin-ning or each regular issue. ofthe PCT Gazette.

MECHANISM OF CUSHIONING AND RETRACTION FOR A DRILLING DEVICE FIELD OF THE INVENTION The present invention relates, in general, to diagnostic instruments and, more particularly, to a; system and method for the repositioning of a movable housing, to the damping of a lancet using a secondary spring.

BACKGROUND OF THE INVENTION The quantitative determination of analytes in bodily fluids is of great importance in the diagnosis and maintenance of certain physiological abnormalities. For example, lactate, cholesterol and bilirubin should be monitored in certain individuals. In particular, the determination of glucose in body fluids is important for diabetic individuals who have to frequently check the level of glucose in their body fluids to regulate the consumption of glucose in their diets. One method of obtaining a sample of body fluid, such as a complete blood sample is through the use of a puncture or piercing device. The whole blood sample could be used to monitor an individual's glucose. Existing piercing devices use a lancet to puncture or puncture the skin tissue, allowing a sample of - blood forms on the surface of the skin. Next, the entire blood sample is transferred to the test device. The entire blood sample is often taken from the finger tips of the test subject for glucose monitoring because of the high concentration of capillaries that can provide an effective blood supply. However, taking blood from the tips of the fingers is a disadvantageous condition due to the high concentration of nerve terminals that causes pain and discomfort in many individuals. In addition to the pain and discomfort inherent in pricking or piercing the fingertip, existing piercing devices could cause increased pain in many individuals by failing to adequately cushion the spear after initially piercing the skin. This could cause multiple perforations in the individual's skin, requiring additional healing time and increased user discomfort.

Alternately, excessive cushioning can reduce the force of the lancet and adversely affect the depth of the perforation, causing insufficient sample size and the need to puncture once more. It would be desirable to have a puncture or piercing device and method that addresses these problems while decreasing the number of components required to manufacture the piercing device and, thereby, decreasing the total cost of the device.

SUMMARY OF THE INVENTION According to one embodiment of the present invention, a puncturing or piercing device is described. The piercing device comprises a main housing having an internal surface enclosing a portion of the piercing mechanism. The puncture or piercing mechanism includes a lancet fastener attached with an axis and a drive spring that surrounds a portion of the shaft. The drive spring is located between the lancet holder and the inner surface. The piercing mechanism is adapted to move between a rest position, a firing position and a lancing position. The punching or piercing device further comprises a movable housing adjacent to the main housing. The movable housing is adapted to move from a rest position to a position of shot. The movable housing has an internal surface that encloses a portion of the axis of the drilling mechanism. The enclosed portion of the shaft has a retainer and a secondary spring that surrounds at least one section of the shaft. The secondary spring is located between the retainer and the inner surface of the movable housing. The secondary spring is adapted to move the movable housing from the firing position to the rest position. The secondary spring is further adapted to move the piercing mechanism from the lancing position to the rest position. According to another embodiment of the present invention, a method for damping a lancet using the punching or piercing device described above is described. The method includes the steps of providing the previously described perforating device and compressing the driving spring and the secondary spring through the displacement of the movable housing out of the main housing towards the firing position. The method further includes the steps of decompressing the secondary spring to move the movable housing from the firing position to the rest position, adjacent to the main housing and driving the actuation spring: causes the lancet holder to move from the firing position to the puncture position. The method further comprises the steps of re-compressing the secondary spring as the lancet holder moves from the firing position to the lancing position and decompression of the secondary spring moves the lancing holder from the lancing position to the lancing position. the position of. repose. It is not intended that the foregoing summary of the present invention represent each embodiment, or each aspect of the present invention. This is the purpose of the figures and the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other advantages of the invention will be apparent on the basis of reading the following detailed description and based on the reference to the drawings. Figure 1 is a perspective view of a piercing device and an end cap according to an embodiment of the present invention. Figure 2 is a front view of the piercing device of Figure 1. Figure 3 is a front view of the piercing device of Figure 1 with a lancet received therein. Figure 4 is a cross-sectional view of the piercing device of Figure 1 with a lancet received therein, the piercing device being in a rest position.

Figure 5 is a cross-sectional view of the perforating device of Figure 1 in a firing position. Figure 6 is a cross-sectional view of the perforating device of Figure 1 in a fired position. Figure 7 is a cross-sectional view of the perforating device of Figure 1 in a penetrating position. Figure 8 is a front view of a push button of the piercing device of Figure 1, according to an embodiment of the present invention. Figure 9 is a perspective view of a drilling mechanism contained within the drilling device of Figure 1, according to one embodiment of the present invention. While the invention is susceptible to various modifications and alternative forms, the specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms described. Rather, the invention is to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the invention as defined by the appended claims.

DESCRIPTION OF ILLUSTRATIVE MODALITIES The present invention is directed to a puncture or piercing device that is adapted to receive a lancet for use in the removal of a body fluid from a test subject. In general, the body fluid contains at least one analyte that could then be examined to determine its concentration in the body fluid sample. The puncture or piercing devices and lancets could be used to produce a sample of blood or body fluid from a test subject. Then, this sample could be analyzed with a meter and a test strip, or similar device, to determine the concentration of the analyte that will be examined. Examples of the types of analytes that could be collected with a device, drilling include glucose, lipid profiles (eg, cholesterol, triglycerides, LDL and HDL), microalbumin, hemoglobin A1C, fructose, lactate or -bilirubin. Next, with reference to the drawings and initially to Figures 1-3, there is illustrated a punching or perforating device 10 for obtaining a fluid sample from a test subject, according to an embodiment of the present invention. The piercing device 10 has a main housing 12 with a movable housing 14 movable relative to the main housing 12. The main housing 12 includes a first main housing portion 12a and a second main housing portion 12b. The first and second main housing portions 12a, b could be removably attached or they could be formed or molded as a permanently attached piece. An end cap holder 16 is connected to the main housing 12 at the test end of the piercing device 10. An end cap 18 could be removably attached to the end cap holder 16. When it is attached, the end cap 18 is retained on the end cap holder 16, for example, by a pair of support arms 20a-b integrally formed with the end cap holder 16. When used, the movable housing 14 is removed from the main housing 12 to move an internal piercing mechanism to a fired position, and subsequently, the push button 22 is depressed to operate the piercing mechanism 24 (Figure 9) so that a sharp tip of a lancet 34 of a lancet 30 is forced to pass through an opening (not shown) formed in the end cap 18. The pricking or piercing device 10 could be provided with a number of different end caps 18, each with a different width for facilitate the formation of skin punctures of different depths. Alternatively, the end cap 18 could include an adjustable disc 26 which allows perforations of different depths to be made using a single end cap 18. Figures 2-3 illustrate the piercing device 10 with the end cap 18 removed . The lancet holder 36 includes a generally cylindrical central opening 28 which is formed therein. The opening 28 is adapted to receive the lancet 30, as illustrated in Figure 3. The lancet 30 includes a lancet body 32 with a sharp-pointed lance 34 extending therefrom. The lance 34 could be enclosed within a protective cover 70 (Figure 9) to protect the user from unintentional perforations. In addition, the protective cap 70 helps to preserve the lance 34 from being contaminated before use and could also be replaced after the use of the lance 34, before discarding the lancet 30. Also, with reference to Figure 4, A cross-sectional view of the pricking or piercing device 10 is illustrated in a rest position with the end cap 18 separated. The lancet holder 36 is connected to an elongated shaft 38 by being integrally formed therewith. The shaft 38 has a retainer 40 which is supported within the movable housing 14. A driving spring 42 is located about the axis 38 between the lancet fastener 36 and a spring stop 44 integrally formed with the first main housing portion 12a. Movable housing 14 has a pair of elongated columns 48a, b integrally formed therewith. Each of the columns 4.8a, b extends towards the main housing 12 through an opening (not shown) formed in the first main housing portion 12a. A secondary spring 46 is located around the axis 38 within the movable housing 14. A first end of the secondary spring 46 is located against the inner surface of the movable housing 14 and a second end of the secondary spring 46 is located against the shaft retainer 46 38. The secondary spring 46 is positioned centrally within the movable housing 14 along the longitudinal axis of the piercing device 10. Figure 4 illustrates the interior of the piercing device 10 when it is not in use. position, the lancet holder 36 is located in a resting position between a lancing position and a fired position.In the rest position, both the driving spring 42 and the secondary spring 46 are substantially decompressed and are in equilibrium. Fig. 5 illustrates the interior of the puncture or piercing device 10 (the lancet 30 is not shown) when The lancet holder 36 and the movable holder 14 are in a firing position in which the movable housing 14 has been pulled out of the main housing 12. In the firing position, both the drive spring 42 and the secondary spring 46 are substantially compressed as the user moves the movable housing 14 out of the housing 12 in the direction of the Arrow A., with reference to Figures 4-6 and Figure 8, to move the lancet holder 36 from its rest position to its fired position, the movable housing 14 is pulled from the main housing 12 in the direction of the Arrow A. movable housing 14 continues to be pulled, against the force of the driving spring 42 and the secondary spring 46, until a plurality of angled stop members 50a, b formed on the lancet holder 36, move through (toward the right as illustrated in Figures 4-6) of a plurality of capture arms 52a, b located on the push button 22 (as best illustrated in Figure 8). Each of the capture arms 52a, b has a respective end 53a, b adapted to engage the angle stop members 50a, b. The ends 53a, b of the capture arms 52a, b are at angles opposite the angle stop members 50a, b, so that when the angled stop members 50a, b are moved in the direction of the arrow These make contact with the ends 53a, b of the capture arms 52a, b. The movement of the corner stop members 50a, b forces the ends 53a, b of the capture arms 52a, b, as well as the attached push button 22, to be directed in the direction of the first main housing portion. 12a. Once the angle stop members 50a, b have moved through the ends 53a, of the capture arms 52a, b, a spring mechanism 64 (Figure 8), located between the second main housing portion 12b and the push button 22, forces the capture arms 52a, b to move towards the first housing portion 12a. This movement causes the ends 53a, b of the capture arms 52a, b to engage the angled stop members. 50a, b. In this position, the movement of the lancet fastener 36 in the direction of the Arrow B due to the driving spring 42 is avoided. Once the angled stop members 50a, b have been engaged, the user releases the movable housing 14. and allows the now compressed secondary spring 46 to urge the movable housing 14 to return to its initial position adjacent the main housing 12, as illustrated in Figure 6. The piercing device 10 is now in its fired position, where the drive spring 42 is substantially compressed, while secondary spring 46 is substantially decompressed. The lancet holder 36 is guided between its rest and firing positions through a guide shoulder 56 (Figure 9) formed on a portion of the lancet holder 36. The guide shoulder 56 travels within a groove 58 formed between a pair of elevated guide rails 60a, b formed in an inner portion of the first main housing 12a. To perform a puncture on the skin of a test subject, the end cap 18 is attached to the piercing device 10. The lancing holder 36 could be in the fired position at the time the end cap 18 is attached or it could be fired once the end cap 18 has been removably attached with the end cap holder 16. Next, the end cap 18 is firmly placed against the skin where the piercing will be performed, and the push button 22 is pressed. Pressing the push button 22 causes the capture arms 52a, b (Figure 8), integrally formed with the lower part of the push button 22, to move towards the first main housing portion 12a outside the lancet holder 36. From this In this manner, the lancet holder 36 is no longer prevented from moving in the direction of the Arrow B by contacting the ends 53a, b of the capture arms 52a, b with the angular stop members 50a, b of the lancet fastener 36. The spring mechanism 64 (Figure 8), for example, of an elastically deformable foam material, is located between the push button 22 and a portion of the main housing 12 for biasing the push button 22 to its non-position. triggered Based on the release of the lancet holder 36 as described above, the driving spring 42 will force the lancet holder 36 to continue in the direction of the Arrow B until the sharp point of the lance 34 (Figure 3) pass through opening 24 in end cap 18 to perform punching or piercing. As the lancet holder 36 moves in the direction of the Arrow B, the attached shaft 38 also moves in the direction of the Arrow B. The retainer 40 of the shaft 38 causes the secondary spring 46 to compress as it moves. the lancet holder 36 moves to the puncture position. Eventually, the return force of the compressed secondary spring 46 becomes larger than the puncturing force of the driving spring 42. At this point, the return force of the secondary spring 46 causes the lancet holder 36 to change direction and return to its rest position moving in the direction of Arrow A. Alternately, in some embodiments a stop member is provided to stop the lancet holder 36 from moving too far in the direction of Arrow B, at which time the secondary spring 46 returns the lancet holder 36 to its rest position. However, the lancet holder 36 normally moves in the direction of Arrow A more than required to return to its rest position. In this way, slight recompression of the drive spring 42 causes the lancet holder 36 to move again in the direction of the arrow B. As the lancet holder 36 begins to move back in the direction of the arrow B (due to the light recompression of the drive spring, 42), the secondary spring 46 is again compressed. The force required to recompress the secondary spring. 46 effectively dampens the movement of the lancet holder 36. This cushioning helps prevent or prevent the drive spring 42, and its natural tendency to oscillate (because it is being elastically deformed), from causing a second Unintentional piercing of the skin. Next, with reference to Figure 8, pushbutton 22 is illustrated according to one embodiment of the present invention. The push button 22 includes a body 62 from which the two capture arms 52a, b extend. Each of the capture arms 52a, b includes one end 53a, b in a respective manner, opposite the body 62. Each end 53a, b is adapted to engage with an angled stop member 50a, b of the lancet holder 36. A spring mechanism 64, such as an elastically deformable foam, is located on the lower part of the body 62. When the push button 22 is incorporated in the piercing device 10, the spring mechanism 64 makes contact with a portion of the second. main housing portion 12b for biasing the push button 22 in the non-actuated position, as discussed above with respect to Figures 4-6. Next, with reference to Figure 9, a perspective view of the lancet 30 located within the lancet holder 36 is illustrated. The lancet 30 is shown with a protective cover 70 having a portion that is integrally formed with the body. of lancet 32 and covering the sharp tip of the lance 34. Before using the piercing device 10, the lancet body 32 of a new lancet 30 is inserted into the cylindrical opening located in the lancet holder 36, and subsequently, the protective cap 70 is rotated from the lancet assembly 30 in the direction of the Arrow C shown in Figure 9. The lancet holder 36 includes a guide projection 56 that is adapted to be inserted into the groove. 58 (Figures 5-6). The guide shoulder 56 and the slot 58 are adapted to assist in providing a linear puncture of the skin of the test subject by the lancet 30. Linear punctures are preferable because they tend to produce less pain and faster healing by puncturing the skin . The structure of the punching or piercing device 10 described above provides a number of advantages not previously realized through common piercing devices. For example, the secondary spring 46 is used both to move the movable housing 14 from the firing position to the rest position, as well as to return the lancing holder 36 from its lancing position to its rest position. Therefore, the piercing device 10 is, fully functional using only two springs. The use of two opposing springs allows the puncture resistance to be adjusted simply by regulating the spring ratio between the drive spring 42 and the secondary spring 46, reducing the need to calculate the friction interaction and the mass of the various components of the spring. device. Commonly, the spring constant of the driving spring 42 is larger than the spring constant of the secondary spring 46, which causes the secondary spring 46 to be initially compressed by the force provided by the driving spring 42. The perforating device 10 described above also allows both the driving spring 42 and the secondary spring 46 to remain floating freely on the shaft 38. In this way, the need to join one or both ends of each -spring is eliminated, decreasing the cost and time required to manufacture the piercing device 10. While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes could be made thereto without departing from the spirit and scope of the present invention. Each of these modalities and obvious variations thereof is contemplated to fall within the spirit and scope of the claimed invention, which is pointed out in the following claims.

Claims (13)

1. CLAIMS 1. A piercing device, characterized in that it comprises: a main housing having an internal surface that encloses a portion of a piercing mechanism, the piercing mechanism includes a lancet holder attached with a shaft and a driving spring surrounding 'a portion of the shaft, the driving spring is located between the lancet holder and the inner surface, the piercing mechanism is adapted to move between a rest position, a firing position and a lancing position; and a movable housing adjacent to the main housing, - the movable housing is adapted to move from a rest position to a trip position, the movable housing has an inner surface enclosing a portion of the axis of the piercing mechanism, the enclosed portion of the housing. The shaft has a retainer and a secondary spring that surrounds at least one section of the shaft, the secondary spring is located between the retainer and the inner surface of the movable housing, wherein the secondary spring is adapted to move the movable housing from the firing position. in the rest position, the secondary spring is further adapted to move the piercing mechanism from the lancing position to the rest position. The drilling device according to claim 1, characterized in that the secondary spring has a spring constant which is smaller than the spring constant of the driving spring. 3. The piercing device according to claim 1, characterized in that the driving spring is not connected with the lancet holder or with the internal surface of the main housing. The drilling device according to claim 1, characterized in that the secondary spring is not connected to the shaft retainer or to the internal surface of the movable housing. The drilling device according to claim 1, characterized in that neither the drive spring nor the secondary spring are connected with any component of the drilling mechanism. The piercing device according to claim 1, characterized in that the secondary spring surrounds the entire portion of the shaft enclosed within the movable housing. 7. A method for damping a lancet, characterized in that it comprises the steps of: providing a drilling device that includes (i) a main housing having an internal surface enclosing a portion of a drilling mechanism, the mechanism of The perforation includes a lancet holder attached with an axis and a drive spring that surrounds a portion of the shaft, the drive spring is located between the lancet holder and the inner surface, the piercing mechanism is adapted to move between a position of rest, a firing position and a puncture position; and (ii) a movable housing adjacent to the main housing, the movable housing is adapted to move from a rest position to a trip position, the movable housing has an internal surface enclosing a portion of the axis of the piercing mechanism, the portion enclosed by the shaft has a retainer and a secondary spring surrounding at least a portion of the shaft, the secondary spring is located between the retainer and the inner surface of the movable housing; compressing the drive spring and the secondary spring by moving the movable housing out of the main housing to the trip position; decompressing the secondary spring to move the movable housing from the firing position to the rest position, adjacent to the main housing; actuating the drive spring causing the lancet holder to move from the firing position to the lancing position; re-compress the secondary spring as the lancet holder moves from the firing position to the lancing position; and decompressing the secondary spring to move the lancet holder from the -punch position to the rest position. The method according to claim 7, further characterized in that it comprises the step of adjusting the elasticity ratio between the driving spring and the secondary spring to regulate the force applied to the lancet holder as it moves from the position of firing to the puncture position. The method according to claim 7, characterized in that the drive spring is not connected with the lancet holder or with the internal surface of the main housing. The method according to claim 7, characterized in that the secondary spring is not connected to the shaft retainer or to the internal surface of the movable housing. The method according to claim 7, characterized in that neither the drive spring nor the secondary spring are connected with any component of the drilling mechanism. 12. The method in accordance with the claim 7, characterized in that the secondary spring has a spring constant less than the spring constant of the drive spring. The method according to claim 7, further characterized in that it comprises the step of piercing the skin of a test subject with a lancet received by the lancet holder as the lancet holder moves from the firing position. to the puncture position.