MXPA00000880A - Lancing device causing reduced pain - Google Patents

Abstract

A lancing device has a spring-loaded lancet holder slidably mounted within a housing for carrying a disposable lancet and needle. A knob on the back of the device has forward-extending fingers that stop the lancet holder at an adjustable predetermined point after the device has been fired. The fingers not only control the penetration depth of the needle, but also absorb vibrations and reduce noise to cause less pain to the user.

Description

LANCET DEVICE THAT REDUCES PAIN BACKGROUND OF THE INVENTION 1. - FIELD OF THE INVENTION This invention relates to a lancet device for traversing the skin in order to obtain a blood sample; more in particular, a lancet device that causes less pain to the user. 2. - BACKGROUND OF THE RELATED TECHNIQUE Lancet devices are an unfortunate reality for the millions of people with diabetes who have to test their blood glucose levels up to 5 or more times each day. Typically, these people use the devices to draw a drop of blood from a finger, apply the blood on a disposable strip, and measure the concentration of glucose in the blood in a meter. The obvious goals of such lancet devices are to provide a sufficient blood sample with minimal pain, minimal inconvenience and minimal cost to the user. U.S. Patent 4,503,856, issued March 12, 1985 to Cornell et al, discloses a lancet device having a tubular housing, a sliding lancet holder in the housing, and a compressible spring that provides the force to move the lancet fastener. linear way to a position to traverse the skin, after which it returns to a neutral position. U.S. Patent 4,527,561, issued July 9, 1985 to Burns, discloses a lancet unit that includes a second spring for retracting the lancet holder after the lancet has penetrated the skin of the user (see also U.S. Patents 4,535,769 Y 4,553,541). U.S. Patent 4,895,147, issued January 23, 1990 to Bodicky et al, discloses a lancet device that includes a depth of penetration selector and a mechanism to create a vacuum after the skin has been traversed to help draw blood of the puncture site. US Patent 4,976,724, issued December 11, 1990 to Nieto et al, discloses a lancet device that includes a mechanism that allows the user to eject a used lancet without touching it. U.S. Patent 5,318,584, issued June 7, 1994 to Lange et al, discloses a lancet device that includes a rotary / sliding transmission system that allows a puncture to be made with an adjustable / reproducible depth of penetration and with less pain.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a lancet device for drawing a blood sample. It consists of a generally elongated housing having a cap with a through hole at an anterior end and containing: (a) a lancet holder, slidably mounted within the housing, (b) a first spring for pushing the holder forward , having a first end related to the housing and a second end related to the fastener, (c) a slider, slidably mounted on a wall of the housing, comprising (i) a projection off the wall and (ii) a pushing means, which is reversibly coupled to the fastener, for pushing the fastener back to a raised position and for pushing a lancet forward from the device, (d) a second spring for pushing the return fastener, which has a first end that is related to the fastener and a second end related to the slider, (e) a button, movable between a first position in which the fastener is restricted when the The device is lifted and a second position in which the restriction is removed, allowing the first spring to push the clip forward, and (f) a closure at the rear end, consisting of (i) a plurality of elements extending forward to stop the forward movement of the fastener in a predetermined position and (ii) an adjustment means to controllably change and adjust the predetermined position. The present device causes less pain during the lancet application procedure, since the oscillations and noise of the needle are reduced in comparison with the lancet application devices of the prior art. In addition, control of the depth of penetration from the back of the device provides advantages over devices in which the depth control is at the front. It allows the present device to have an inexpensive front cover, which is desirable since contamination of the latter may require it to be replaced. Thus, also, by controlling the penetration depth at the back of the device, the fingers that are holding the device are less likely to hide the depth setting.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a device of this invention to which half of the housing has been removed.

Figure 1a is an enlarged view of the rear end of the device of Figure 1. Figure 2 is a cross section of the device of Figure 1 in its rest position. Figure 3 is a cross section of the device of the figure 1 when it is getting up. Figure 4 is a cross section of the device of Figure 1 in a very upright position. Figure 5 is a cross section of the device of Figure 1 when lifted. Figure 6 is a cross section of the device of Figure 1 while it is firing.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a lancet device that provides a mechanism that reduces noise and vibration to cause less pain during the lancet application operation. Figure 1 describes a lancet device 10 of this invention, which has one side of the housing removed to allow an interior view. The front end of the device has a lid 12, with an orifice 14. The lid 12 is removably attached, for example by means of a screw thread, to the housing 16, which is conveniently formed of two parts. One half 16a is shown, while the other half has been removed. At the rear end of the cover in front of the device 12, the housing 16 is attached to the knob 18. The knob 18 has cantilevered projections 18a that provide a mechanical stop, whose position can be varied by a thread, such as a spiral thread, which joins the knob to the housing. A lancet holder 20 holds and guides a disposable lancet during the entire operation of the device. A pulse spring 22 stores the energy needed to drive the lancet forward. The thrust spring 22 is contained within the fastener 20 and is related to the post 23 of the housing. A second "retraction" spring 24, which is also contained in the fastener 20, provides a mechanism for removing the lancet needle from the skin after the lancet has been punctured. The spring constant of the retraction spring 24 is substantially less than that of the thrust spring 22; therefore, the thrust spring 22 is substantially "stronger". The slider 26 is slidably mounted on the housing 16 and has a projection 26a outside the housing that can be moved manually - backward to lift the device and forward to eject the lancet. When the device is being lifted, the slider 26 engages the fastener 20. The button 30 is mounted through the housing, with the tongue 30a projecting into the housing. After the device is lifted, pressing the button 30 releases the restriction on the lancet holder 20 to allow the spring 22 to push the holder forward. The reference to element 30 as a "button" is not to suggest that the illustrated actuator element is the only one contemplated. In this specification and in the appended claims, it should be understood that button is generally applied to any actuator, of the type well known in the art, which can release the restriction on the lancet holder. Figure 1A describes an extension of the rear portion of the lancet device 10. In a preferred embodiment of the mechanical stop feature, described herein, the cantilevered projections 18a, which extend forwardly from the knob 18, have front ends of biased cut, which form protrusions that extend inward. When the fastener 20 moves forward, in the direction shown by the arrow on the left, the flange of the fastener 20a finally contacts the projections of the cantilevered ends 18A. The strength of the flange of the fastener 20 causes the projections to bend, which decreases or absorbs impact vibration and reduces noise. These two effects reduce the pain caused to the user. The position of the protuberances in relation to the front of the device determines how deep the lancet needle will penetrate the skin. That position, in turn can be adjusted by turning knob18, which runs on thread 18B. The indicator 18C which is on the knob, together with marks in the housing (not shown), allows the device to be adjusted to given and reproducible puncture depths given. Variable puncture depths are desirable, since the user usually wants to provide only enough blood for the particular test and because the characteristics of the user's fingers are different. By providing a depth scale of approximately 1.8 mm in approximately 7 steps, the needs of almost all potential users can be met. The operation of the lancet device can be understood with the help of a series of figures showing the configuration of the elements of the device in order during the operation of the device. Figure 2 shows a cross-section of the device at rest, with the internal part 26B of the slider 26 resting against the upper part 28A of the detachable connector 28. The impulse spring 22 and the retraction spring 24 are in equilibrium, one in relation to the other. Both springs are compressed, the thrust spring 22 much less than the return spring 24, since its spring constant is much greater. The lancet 40 and the needle 42 are seen inside the lid 12. Figure 3 shows a cross section of the device in an intermediate position while it is in the process of being lifted, by the slider 26 being moved backwards (to the right in figure 3). The force exerted by the backward movement of the thrust element 26C of the slider 26 causes the retraction spring 24 to be compressed more than in Figure 2. Due to its much greater constancy of elasticity, the thrust spring 22 remains relatively uncompressed . Figure 4 illustrates the lancet device when it is in the very raised position; that is, the slider 26 has been moved to a later position farther. The cantilever extension 44 of the lancet holder 20 has moved slightly further (to the right) from the stop of the housing 46. The impulse spring 22 is compressed and the retraction spring 24 remains compressed to approximately the same degree as in the figure 3. Figure 5 describes the lancet device when it is lifted and at rest. The thrust spring 22 is forcing the extension 44 of the lancet holder 20 against the housing stop 46. The slider 26 has returned to its initial position (FIG. 2). The retraction spring 24 is less compressed than in FIGS. 3 and 4. If the button 30 is now depressed, the tab 30A pushes the extension 44 without the stop 46 constituting an obstacle (below) and allows the lancet holder. 20 is pushed forward (to the left) in response to the force exerted by the compressed pulse spring 22. That sequence leads to the instantaneous situation described in FIG. 6, in which the lancet 40 has reached its left position. extreme, with the needle 42 coming out through the opening of the lid 14. The protuberances in the cantilevered projections 18A, which are internal elements of the knob 18, have stopped the forward movement (to the left) of the fastener of lancet 20. As mentioned above, the cantilever projections deviate slightly, by means of which they absorb some vibrations and reduce the noise to reduce pain to the user. These effects are intensified, in the preferred embodiment shown, by cutting at a corresponding angle the protuberances in the projections 18A and flange 20A, so as to make contact in a large area. The slider 26 is still in its initial position. The thrust spring 22 has moved forward with the fastener 20 and is not compressed. The retraction spring 24 is compressed, whereby it will exert a backward (right) force on the fastener 20, resulting in the lancet 40 and needle 42 retracting and the configuration of the elements returning to the which is shown in Figure 2. Those skilled in the art will understand that the description and the foregoing figures illustrate the practice of the present invention, but in no way limit it. Variations of the detail presented herein can be made without departing from the scope and spirit of the present invention.

Claims (3)

NOVELTY OF THE INVENTION CLAIMS

1. - A lancet device for obtaining a blood sample, comprising a generally elongated housing having a cover with a through hole at an anterior end and containing a) a lancet holder, mounted slidably within the housing, b ) a first spring for pushing the fastener forward, having a first end that is related to the housing and a second end related to the fastener, c) a slider, slidably mounted on a wall of the housing, consisting of: i) a projection off the wall and ii) a pushing means, which reversibly engages the fastener, to push the fastener back into a raised position and to push a lancet forward from the device, d) a second spring for pushing the clip back, which has a first end that is related to the clip and a second end related to the slider, e) a button, movable between a pr It is a position in which the fastener is restricted when the device is lifted and a second position in which the restriction is removed, allowing the first spring to push the fastener forward and f) a closure at the rear end, comprising: i) a plurality of forwardly extending elements for stopping the forward movement of the fastener in a predetermined position and ii) an adjustment means for controllably changing and adjusting the predetermined position.

2. The device according to claim 1, further characterized in that the forwardly extending members comprise cantilevered projections having projections extending inwardly to engage a surface of the fastener.

3. The device according to claim 1, further characterized in that the adjustment means consists of a spiral thread to join the closure to the housing, by means of which when rotating the closure on the housing are placed forward and backward the elements that extend forward.