Patent Application
20100049234
The present invention relates to a lancet assembly constituted from a lancet and a lancet case that houses the former, an injector used in combination with such lancet assembly, and a pricking device constituted from such lancet assembly and such injector. Such device is used in pricking a predetermined portion of a body with a sharp pricking member such as a needle for sampling a body fluid such as blood.
Various pricking devices have been used to take a small amount of blood for the purpose of measuring the blood sugar level of patients with diabetes. Such a device is constituted from a lancet having a pricking member (for example a needle formed from a metal) that pricks a predetermined portion of the body of a patient and an injector. The lancet is incorporated in the injector that launches the lancet with the pricking member exposed at the distal end thereof, the lancet being launched toward the predetermined portion by making use of the expanding action of a compressed spring provided in the injector.
When taking an amount of blood by using such a pricking device as described above, particular attention must be paid in the handling of the lancet that has been used. In the lancet that has been used, typically the distal end portion of the pricking member that bears a trace of the patient's blood is exposed from a lancet body. Should a portion of the body of a person other than the patient, for example a nurse who takes the blood sample, accidentally touches the distal end portion of the pricking member, the body portion may be pricked by the distal end portion of the pricking member causing a cut through which the patient's blood may enter the other person's body, thus posing the danger of infection of a disease.
Known pricking devices are not necessarily designed with due consideration given to the handling of the lancet that has been used. For example, it has been proposed to apply a cap on the exposed distal end portion of the pricking member after the pricking operation (refer to Patent Document 1 which will be mentioned later). This device requires the lancet to be carefully handle the lancet in the state of its distal end thereof exposed so as to apply the cap thereon, and therefore the danger described above is not sufficiently eliminated.
Accordingly, the pricking device requires utmost attention in handling the lancet after it has been used, and there is a demand for a pricking device that allows the lancet to be handled after safety thereof has been ensured.
Patent Document 1: U.S. Pat. No. 5,385,571
It is an object of the present invention to provide a pricking device that allows a lancet to be removed from an injector after isolating a protruding distal end portion of a pricking member from its surrounding, rather than removing the lancet from the injector with the distal end portion of the pricking member remaining in the state of protruding from a lancet body, after pricking.
In the first embodiment, the present invention provides a lancet assembly comprising a lancet and a lancet case that houses a portion of the former, wherein
the lancet comprises a lancet body, a lancet cap and a pricking member (generally, a pricking member made of a metal);
the lancet case comprises a case body having a front end opening and a rear end opening, and a pair of wings disposed on sides of the case body;
as for the lancet, the pricking member is disposed in the lancet body and the lancet cap while straddling over these members, and the distal end portion of the pricking member being enclosed by the lancet cap;
the lancet body has a protruding portion and a stopper located behind the protruding portion;
when the rear end portions of the wings are not fitted into the sides of the case body, the rear end portions are located outwardly from the case body, so that the wings protrude backward and obliquely from the sides of the case body; and
when the rear end portions of the wings are fitted into the sides of the case body, the wings extend along the sides of the case body (as a result, the rear sides of the abutting portions become able to contact the front sides of the protruding portions of the lancet body, and thereby the forward movement of the protruding portions is restricted). With such lancet assembly, it is that the lancet is a resin molded article (for example, an article produced by the injection molding of a resin).
In one embodiment of the lancet assembly of the present invention, the lancet cap and the lancet body are integrally connected to each other via a weakened portion, and a rear portion of the lancet cap that is located in front of the weakened portion, the weakened portion and a front portion of the lancet body that is located behind the weakened portion are housed in the lancet case as said portion.
In other embodiment of the lancet assembly of the present invention, the lancet cap and the lancet body may also be independent of each other, and in this case, the rear portion of the lancet cap and the front portion of the lancet body are disposed as said portions housed in the lancet case. In one embodiment, the lancet cap and the lancet body may be substantially adjacent to each other without being apart from each other. In another embodiment, these members may be apart from each other, and the pricking member may be partially exposed.
It is noted that when an outward force is applied to the rear end portion of the wing which is fitted in the side of the case body, the rear end portion is elastically able to return to its original shape. That is, the wing substantially splays out.
In the second embodiment, the present invention provides an injector to which has the lancet assembly of the present invention described above or to be described later in detail is set therein, and launches the lancet body with the distal end portion of the pricking member being exposed, the injector comprising therein a plunger that launches the lancet body with the distal end portion of the pricking member being exposed and a member that expands the wing outward (namely a wing splaying member).
In the case wherein the lancet assembly of the present invention and the injector of the present invention are combined and used as the pricking device of the present invention, preparation for the pricking operation is completed only by merely inserting the lancet assembly so as to load it into the injector and twisting off and removing the lancet cap. The pricking device also allows it, after the pricking operation, to remove the distal end portion of the pricking member from the injector in a state of being substantially isolated in the lancet case from the surrounding, although it is still protruding from the lancet body. It is noted that “the state of being substantially isolated from the surrounding” means that the distal end portion of the pricking member is located in the lancet case at a position sufficiently away from the front end opening of the case body, and therefore a person who takes the blood sample does not normally touch the distal end portion in the routine pricking operations.
The lancet assembly of the present invention, the lancet and the lancet case that constitute the same, the injector that is used in combination with the lancet assembly, and a pricking device of the present invention will be described below in detail with reference to the accompanying drawings.
In this specification, directions and positions are described by using the words “front” and “rear”. These words are used by making reference to a certain point (or a member or an element) which can be identified from the context, with the word “front” used to indicate a direction in which the pricking member moves to prick a predetermined portion from said certain point, namely the pricking direction, and the words “rear” is used to indicate the opposite direction. In this specification, directions and positions are described also by using the words “inward” and “outward”. These words are used by making reference to a certain point (or a member or an element) which can be identified from the context, with the word “inward” used to indicate a direction toward the pricking member, and the words “outward” is used to indicate the opposite direction.
The lancet assembly 100 of the present invention is shown in a schematic perspective view of
The lancet 200 and the lancet case 102 that constitute the lancet assembly shown in
The lancet assembly 100 is loaded in the injector 300 by first inserting the rear end portion 108 of the lancet case 102 through the front end opening 302 of the injector into the inside thereof (namely, toward the backward), and then inserting the most portion of the lancet case 102. The lancet case 102 has a bump (or protrusion) 112 provided on the outside of the rear portion of the front end 110. When the bump 112 has gotten over a protruding portion 304 provided on the wall that defines the front end opening 302 of the injector, or loading of the lancet assembly onto the injector is completed.
The state of completing of the loading as described above is shown in
The lancet 200 that constitutes the lancet assembly of the present invention, shown in
It is sufficient that the protruding portion 212 of the lancet body exists in a portion of the circumference of the lancet body, and it is preferable that the protruding portions are formed on portions of the circumference of the pricking member in a symmetrical relationship with respect the pricking member (for example, on the upper and lower sides of the pricking member as shown in
In another embodiment, the protruding portion 212 of the lancet body 204 may be composed of a plurality of separated protruding members provided along substantially the entire circumference of the lancet body as shown in
As to such protruding portion 212 provided on the lancet body as described above, the protruding member is indispensable for the restricting the movement of the lancet body. However, the protruding member is preferably provided but may not necessarily be provided for guiding the movement of the lancet body to help stabilize.
In the case the protruding portion comprises protruding members that have different functions, all of the protruding members may not necessarily be provided on the circumference at the same position of the lancet body with respect to the pricking direction. For example, the protruding member that restricts the movement of the lancet may be disposed at any appropriate position of the lancet body as long as it is ahead of the stopper 213, for instance ahead of the position shown in
Hereinafter in this specification, the mere reference to “the protruding portion of the lancet body” is intended to mean the protruding member that has the function of preventing the movement.
Thus while the protruding portion 212 of the lancet body restricts the forward and backward movements of the lancet body within the lancet case, the protruding portion of the lancet body may be either constituted from protruding members provided at two different positions of the lancet body which are located apart from each other with respect to the pricking direction (namely apart from each other to the front and back). In this case, these protruding members have to be located ahead of the stopper 213.
There is not any specific restriction as to the form of the protruding portion 212 of the lancet body described above, as long as it can restrict the movement. Accordingly, there can be various forms (for example, a single form of pin, bar, ridge, etc.) or a combination of these forms. As will be described in detail later, the wings 116 are formed to be fitted in the side surface of the case body (or extend along the side surface). In thus fitted in state, there may happen such a case wherein the wing presses the protruding portion for some reason (for example, the wing which is to fit in abuts against the top of the abutting portion because of a somewhat larger height of the protruding portion due to dimensional variability caused in the manufacturing process). The protruding portion may also have such a form that decreases the height thereof (i.e. a distance to the top of the protruding portion from the surface of the lancet body) when the wing presses as described above (that is, a flexible form). For example, the protruding portion may have a form of a claw or fold-back similar to the stopper 213 described hereinafter. In this case, it is preferable that the distal end of the protruding portion, that is the claw or the like protrudes obliquely forward from the lancet body, as illustrated. In another embodiment, the protruding portion, especially the protruding member located on the front side, may have such a shape that extends from the lancet body in an L-letter configuration as illustrated, such as the protruding member 230 shown in
The rear end portion 202 of the lancet body 204 is constituted so as to fit into the front end portion of the plunger 310 of the injector that launches the lancet, as will be described later, and the rear end portion 202 has a bump, preferably a bump 218 of a circumferential flange shape on the outside thereof, with the bump being adapted so as to fit in a recess 316 of a complementary shape provided on the inside of front end portion 314 (specifically on a leg to be described later) of the plunger 310. In place of the bump and the recess like these, the bump may be used for the rear end portion of the lancet body and the recess may be used for the front end portion of the plunger.
The lancet body 204 further comprises a surface 221 that opposes to the front side surface of the bump 218. This rearward surface 221 comes into close contact with a seat surface 315 provided on the distal end of the plunger when the rear end portion 202 of the lancet body is grasped by the plunger 310.
The lancet body 204 has a pair of stoppers 213 provided behind the rear of the protruding portion 212. The stoppers have a function of preventing the entry of the stoppers through the rear end opening 107 of the case body 114 after getting out of the rear end opening 107 of the case body 114. That is, with respect to the movement of the lancet body 204 through the rear end opening 107 of the case body 114, the movement in only one direction (namely rearward movement) is allowed and the stoppers 213 can get out of the lancet case through the rear end opening 107 to the outside. However, it is impossible to get from the outside into the inside of the lancet case. As a result, movement of the lancet body in the other direction (namely forward movement) is restricted.
Such stoppers 213 preferably has a form of a protruding portion that extends from the lancet body 204 forward in an outwardly oblique direction, preferably the form of a claw or a fold-back, and are preferably provided in a pair on both sides of and through the pricking member. In another embodiment, the stopper may have an L-letter shape similarly to the protruding member 230 as described above. The stoppers of such a form are designed so as to function as follows: the portion of the lancet body that portion has the stoppers can move from the inside of the lancet case through the rear end opening 107 rearward to the outside, but once the stoppers have passed through the rear end opening, cannot get from the outside of the lancet case through the rear end opening forward into the inside of the lancet case because the distal end portions of the stoppers 213 abut against the outside of the wall that defines the rear end opening 107 and, when the lancet body is subjected to a force acting forward intended to move forward in this state, the stoppers expands further outward. As a result, the stoppers act to prevent the movement only in one direction. By forming the lancet from a resin, the stoppers are caused to function further effectively by making use of the elasticity of the former.
For example, by moving the lancet case forward relative to the lancet body when discharging the lancet assembly from the injector after its use, the lancet body is restricted from moving forward as the stoppers of the lancet body cannot enter the lancet case after the stoppers have been moved through rear end opening to the outside, as will be described later. Since the lancet body is not capable of moving forward, the lancet assembly cannot be reused for the pricking operation once it has been used.
In one preferred embodiment, the lancet cap 206 has a protruding portion 216 that protrudes outward, preferably a protruding portion 216 that extends over substantially the entire circumference at a predetermined position with respect to the pricking direction of the lancet cap. In other embodiment, protruding portions may be provided at two positions that oppose to each other via the pricking member (for example, the upper and lower sides of the lancet cap) or more positions. The protruding portion has an external profile larger than the inner profile of the front end opening of the case body, so that the protruding portion 216 cannot enter the inner space of the lancet case 102 through the front end opening 106. As a result, when the lancet is inserted into the lancet case to form the lancet assembly, the protruding portion abuts against the front end portion of the lancet case so as to prevent the lancet from moving rearward further with respect to the lancet case.
The front portion 214 of the lancet cap 206 has a grip that can be held to break the weakened portion 208 (if any), and the protruding portion 216 is provided behind thereof. The protruding portion 216 preferably extends in the form of a flange provided around the lancet cap, or a bar or ridge provided on the side as illustrated. The protruding portion is adapted to abut against the wall that defines the front end opening 106 of the case body so that the lancet 200 is unable to move further backward relative to the lancet case 102. The grip 214 can be held by fingers to force it through the front end opening of the injector and retract for setting the lancet assembly into the injector 300. Accordingly, the front portion 214 may be formed in a flat configuration as illustrated.
It is preferable that the lancet cap has a fitting portion 217 provided behind the protruding portion 216 described above. The fitting portion is a portion located around the lancet cap, and an outermost portion of the profile of the fitting portion (cross section perpendicular to the pricking direction thereof) has such a shape that fits into the front end opening 106 of the case body. As a result, when the lancet cap is inserted into the lancet case, the fitting portion fits into the lancet case and the protruding portion 216 of the lancet cap resides in front of the front end opening 106 of the case body while being adjacent thereto.
In the case where there is such a fitting portion, it is advantageous in that, when the lancet cap is inserted into the lancet case to assemble the lancet assembly, temporary fixation can be achieved without unnecessary movement of the lancet cap in the lancet case as the fitting portion is fitted in the lancet case. There is no restriction on the form and the number of the fitting portion as long as the fitting portion can fitted into the front end opening of the case body so as to temporarily fix the lancet.
The fitting portion described above preferably has such a form that narrows rearward. With this configuration, the fitting portion located behind the protruding portion has at least one surface that inclines, preferably so as to approach the pricking member, toward the back (namely a sloped surface). When the sloped surface is rotated around the pricking member, the surface moves so as to rise over an edge of the wall that defines the front end opening of the case body. As a result, the lancet cap moves forward relative to the lancet case, when the lancet cap is turned (twisted) relative to the lancet case around the extending direction of the pricking member. This movement causes the weakened portion to receive forces effecting both rotation and pull off, and therefore assists breaking of the weakened portion 208. With this regard, the sloped surface is preferably formed so as to make contact with the edge of the wall that defines the front end opening of the case body when the lancet cap is turned around the pricking direction.
As shown in
The fitting portion located behind the protruding portion 216 may be either an extension of the rear portion of the protruding portion (hence integral with the protruding portion) as illustrated, or an independent portion spaced apart from the protruding portion. The narrowing form, when it is provided, may be such a form as a portion or whole of the fitting portion that narrows as described above. The lancet of the present invention shown in
In one embodiment of the present invention, it is preferable that the fitting portion of the lancet cap has such a form that is press-fitted in the front end opening of the case body, and the protruding portion of the lancet cap is held in the condition of abutting against the front end opening of the case body in the state of lancet assembly. In this case, when the fitting portion has the narrowing form in a portion thereof, the sloped surface that defines it assists press-fitting of the fitting portion in the front end opening of the case body.
When the fitting portion that is fitted as described above is provided, the lancet is temporarily fixed within the lancet case in the state shown in
In the lancet 200 as described above, the lancet body 204 and the lancet cap 206 are connected such that the weakened portion 208 is broken by applying such a force that the lancet body 204 and the lancet cap 206 turn in the opposite directions around the extending direction of the pricking member 210, or applying such a force that the lancet body and the lancet cap move away from each other along an extending direction of the pricking member. Then, when the lancet cap 206 is moved away from the lancet body 204, the distal end of the pricking member 210 is exposed from the lancet body.
In the embodiment illustrated, the case body 114 of the lancet case 102 has a form of square cylinder as a whole. The lancet assembly 100 can be assembled by inserting the rear end 202 of the lancet 200 backward through the front end opening 106 of the case body to the inside thereof. The lancet case 102 has openings 106 and 107 at both ends of the case body 114 that constitutes the lancet case. During the pricking operation, a predetermined portion of human body (for example, a finger tip) to be pricked is applied onto the front end opening 106.
The lancet case 102 that constitutes the lancet assembly of the present invention comprises the case body 114 and the wing 116 disposed on the side surface thereof. The wings 116, which may be called arm-like member, is elongated members that extends obliquely and backward from the side surface of the case body, and it is preferably provided in a pair on the opposing side surfaces of the lancet case. The wings 116 have abutting portions 122 that protrude inwardly between the front end portion 118 and the rear end portion 120 thereof. The front end portion 118 is integrally connected to the case body 114, and the rear end portion 120 is detached from the case body in a free state, that is, the state wherein the wing 116 splays out. It is noted that wing 116 is in the state wherein the wing 116 splays out a little outward from the case body as shown in
The lancet case is preferably a molded article of a resin. When a force is applied from the outside on the wings 166 to get in the state wherein the rear ends of the wings are fitted in the side of the case body as shown in
When the wing is located along the side of the case body as shown in
Fitted of the wing 116 into the receiving space 127 is preferably achieved by the snap fit or the press fit of the whole of the part (for example, the rear end portion) of the wing. In the latter case, the wing 116 has a protruding portion 129 in its side, and the receiving space 127 includes a recess 131 as a space into which such protruding portion is fitted. Also, the protruding portion 129 preferably has a shapes which gradually flares rearward, specifically the triangle wing as shown. In this case, the fitting of the rear end portion of the wing into the side of the case body gets easy, and also an outward force which is required to be applied to the rear end portion so as to allow the wing to return its original shape from its being fitted into the side.
It is noted that in the lancet case as shown, the width of the rear end portion of the wing is larger, and the width of the wing ahead of the rear end portion is smaller a little. As a result, there is formed small slits 121 between the case body and the both sides of the wing (see
The state of the lancet assembly according to the present invention wherein the wings 116 are splayed out is shown in
In the state wherein the wings 116 are fitted into the receiving space 127, the wings are elastically deformed as described above, and strictly the wings may be curved a little. In order that such curvature is minimized as much as possible, a wall portion located ahead of the front end portion of the wing which wall portion defines the case body is preferably thinner than the other portion of the wall, and in addition to this, it is more preferable that the wing is thinner. The provition of the thinner wall portion in the case body prevents the wing from being substantially curved so that substantially the whole of the wing is located along the side of the case body when the rear end portion of the wing is fitted into the side of the case body. For example, the wall portion which forms the portion ahead of the front end portion 118 of the wing 116 is formed to have a thinner wall thickness portion 133 as shown in
In place of and/or in addition to the application of the force to the rear end portion of the wing as described above, in order that the wing is fitted into the side of the case body, the wing may be designed such that a force is applied to a portion of the wing, for example a portion located ahead of the rear end portion rather than the rear end portion. In a further embodiment, such force is applied to substantially the entire wing. Thus, in other words, such force is applied to at least a portion of the wing.
It is noted that the lancet case preferably have a channel 135 on a side surface inside the case body 114 (a side surface without a wing), the protruding member 215 is guided along and in the channel. As described above, the lancet body 204 may comprise the two kinds of the protruding members 212 and 215, and these protruding members may be located at the same position or different positions with respect to the direction in which the pricking member extends. The embodiment shown in
The lancet case described above is preferably constituted by integrally forming the case body and the wings by molding (particularly injection molding) from a resin such as a polypropylene resin, a polyethylene resin, a polystyrene resin, a POM resin (polyacetal resin), a nylon resin, an ABS resin, a polycarbonate resin, a vinyl chloride resin, an elastomer resin, a silicone resin, a rubber based resin, a PBT resin (polybutylene terephthalate resin), a polyester copolymer resin or the like. As for the lancet, the pricking member is usually made of a metal, for example, a stainless steel, and the other portion may be formed of a resin similar to that of the lancet case, and is preferably formed by the injection molding with the pricking member being inserted.
The lancet assembly composed of the lancet and the lancet case as described above is set into the injector, and a predetermined portion is pricked. In the lancet assembly 100 that is assembled as shown in
In the embodiment of the lancet shown in
With the lancet assembly of the present invention as described above, in the state wherein the lancet is inserted into the lancet case, the weakened portion is positioned in the lancet case, and the protruding portion of the lancet body is disposed between the abutting portions of the wings of the lancet case and the rear end opening of the case body,
(a) a portion (rear portion) of the lancet cap and a portion (front portion) of the lancet body are accommodated in the lancet cap (that is, a portion of the lancet is accommodated);
(b) in the state wherein the wings of the lancet case are fitted in the sides of the case body, the protruding portions of the lancet body can move back and forth between the abutting portions of the wings and the rear end opening of the case body but is prevented from moving further forward by abutting against the abutting portion, and is prevented from moving further rearward by the abutment against the wall that defines the rear end opening of the case body (refer to
(c) in the state wherein the wings of the lancet case have expanded outward from the sides of the case body, the protruding portions of the lancet body do not contact the abutting portions of the wings so as to become capable of moving forward from the abutting portions (refer to
When the lancet assembly 100 that has been assembled as shown in
When the lancet assembly in such a state that the rear end portions of the wings are fitted into the sides of the case body and the entire wings extend along the sides of the case body is inserted through the front end opening into the injector, forces acting on the rear end portions of the wings are released by members that splay the wings outwardly (namely, wing splaying members, for example wedge-shaped members) provided inside of the injector, so that the wings deform to the state of being expanded outwardly. Such splaying members may apply the forces onto not only the rear end portion of the wing, but also the portion located in front thereof.
The lancet is grasped by the plunger of the injector when the lancet assembly of the present invention is loaded on the injector that is combined therewith. Then the relationship between the plunger and the trigger lever changes to “the state of the trigger lever being capable of holding x the plunger”, and then to the state where the wings expand outwardly from the position of being fitted in the sides of the case body. The latter state corresponds to the state of being capable of launching (launchable state, the so-called cocking state in which the lancet can be launched or triggered). The process of shifting to the launchable state will be described in detail below.
As shown in
With this configuration, when the lancet assembly 100 shown in
When the first leg 320 and the second leg 322 splay out as described above, the rear end portion 202 of the lancet body 204 can move further rearward, so that the bump 218 of the rear end portion 202 of the lancet body 204 fits into the recesses 316 and, at the same time, the legs that have expanded outward move to return somewhat so as to restore the original shape. As a result, the rear end portion 202 is held between the legs 320 and 322 and snugly fits into the gap 318, that is, held by the plunger. At this time, it is preferable that the surface 221 that opposes to the front side of the protruding portion 218 of the lancet body makes close contact with the seat surface 315 provided on the distal end of the plunger 310.
The state of the rear end portion 202 of the lancet body grasped by the plunger as described above is schematically shown in
Grasping of the rear end portion of the lancet by the front end portion of the plunger described above is preferably achieved by such a design that the rear end portion of the lancet is fitted into the front end portion of the plunger with a force smaller than the force necessary to substantially begin the compression of the launching spring S1. Specifically, the front end portion of the plunger is composed of a plurality of the legs so that, when the rear end portion of the lancet body is brought into the abutment against the distal end of the leg and then a force is applied further, the legs easily open and the protrusion of the rear end portion of the lancet fits into the recesses formed on the inside of the legs that have opened, and the legs then close due to their elasticity. The elasticity of the legs can be easily obtained by forming the plunger from a resin.
After rear end portion 202 of the lancet body has been held as described above, the lancet assembly 100 is retracted further. Then the rear end portion 202 of the lancet abutting against the front end portion 314 of the plunger forces the plunger to retract so as to compress the launching spring S1. At this time, the protrusion 324 of the plunger retracts gradually, so as to exert a force that gradually pushes upward the trigger lever pivoted by a shaft 326 against the force exerted downward by the trigger lever 328 at the lower edge of the trigger lever (as indicated by the arrows in
Then immediately after the gradually retracting protrusion 324 has passed below the shoulder (corner) 330 located at the rear end of the trigger lever, the shoulder 330 of the trigger lever abruptly moves downward. At this time of moving downward, the front side of the protrusion 324 is in contact or nearly in contact with the rear side of the shoulder 330. If the insertion of the lancet assembly is stopped at this time (that is, if the retraction of the plunger is stopped), the protrusion 324 of the plunger can be put into engagement with or abutment against the shoulder 330 of the trigger lever in such a state that the compressed launching spring S1 is exerting a force directed forward.
Thus the state of the rear end of the trigger lever just having moved downward may be referred to as “the state of the trigger lever being capable engaging with the plunger.” The lancet assembly and the injector are preferably designed such that, when loading the lancet assembly of the present invention, after the above-mentioned state has been achieved, the insertion of the lancet assembly is additionally continued further (namely the plunger is retracted further) so as to open the wings 116 that are in the closed condition. The wings 116 are opened by the wing splaying members 342 provided in the injector. The state of the wings 116 being opened is schematically shown in
It is preferable to design such that the plunger does not retract further when the wings 116 are opened. For example, such a design may be employed as the hitting member 365 provided on the rear end portion 365 of the plunger abuts against the rear inside wall of the pricking depth adjusting knob (or grip) 366 that covers the drum 360 which surrounds the rear end portion and is not capable of retracting further, as will be understood for example from
When the force applied to the lancet assembly is removed at this state, the launching spring S1 that has been compressed expands somewhat so that the plunger moves a little forward. As a result, the protrusion 324 of the plunger abuts against, namely engages with the rear end 330 of the trigger lever and “the launchable state” is established for the first time thus completing the loading of the lancet assembly in the injector. This means that, when this engagement gets undone in this state, the plunger can be caused to instantly move forward by the action of the launching spring S1. This state of the lancet being able to be launched is schematically shown in
Comparison of
The lancet case 102 is fitted in the injector by means of the protrusion 112 thereof and the protruding portion 304 of the injector 300 (therefore, the lancet case and the injector are attached to each other). Therefore, the lancet held by the plunger is caused to move a little forward by the small forward movement of the plunger. It is preferable that the fitting portion is caused to protrude as described above by this forward movement.
In either embodiment, it is preferable that, when the launchable state is achieved, at least a portion of the fitting portion of the lancet cap is positioned ahead of the front end opening of the case body. As a result, the function of the fitting portion to prevent the lancet cap from turning relative to the lancet body is substantially lost so as to enable the lancet cap to turn relative to the lancet body around the pricking member.
In the state where the protruding in the case where is engaged by the shoulder 330 that is located at the rear end of the trigger lever as described above, it is preferable that the gap 318 of front end portion 314 of the plunger 310 does not expand, namely the legs 320 and 322 do not deform to expand outward. In order to prevent such expansion, it is preferable that, in the state of the protruding in the case where abutting against the rear end 330 of the trigger lever as shown in
In the embodiment illustrated, a plate-shaped member 301 extends toward the rear from the upper edge of the end surface of the shoulder 330 located at rear end of the trigger lever. The plate-shaped member 301 is adapted such that an inward force is exerted between the protrusion 303 that supports it and the shaft 326, and an outward force is exerted in the portion ahead of the shaft 326. With this configuration, the inward force is always exerted at the rear end of the trigger lever so as to achieve “the state of the trigger lever being capable of engaging with the plunger” and “the launchable state” as described above. When a button 350 is depressed inward to launch the lancet, the plate-shaped member 301 presses the protrusion 303 and undergoes elastic deformation, so that a force is exerted by the deformation to push back the button.
The above description relates to the embodiment in which the wings 116 are opened after “the state of the trigger lever being capable of engaging with the plunger” has been achieved. In another embodiment, such a design may also be employed as the wings 116 begin to open before “the state of the trigger lever being capable of engaging with the plunger” is achieved, and the wings 116 become fully open when the state “the state of the trigger lever being capable of holding (or engaging with) the plunger” has been achieved.
In the latter embodiment described above, it is also preferable that the lancet assembly is set in the injector with the plunger being retracted a little, after “the state of the trigger lever being capable of engaging with the plunger” has been achieved and, as a result, at least a portion of the fitting portion of the lancet cap protrudes from the front end opening of the case body in “the launchable state.”
In a further embodiment, such a design may also be employed as the wings 116 begin to open before “the state of the trigger lever being capable of engaging with the plunger” is achieved, and the wings become fully open substantially at the same time as “the state of the trigger lever being capable of engaging with the plunger” is achieved. These various embodiments can be achieved by, for example, shifting the position of the wing splaying member forward or rearward within the injector. In other embodiment, it can be achieved also by changing the length of the wings.
According to this embodiment, upon loading the lancet assembly into the injector, when the lancet assembly is inserted through front end opening of the injector, the rear end portion of the lancet abuts against the front end portion of the plunger. When the inserting action is continued thereafter, the rear end portion of the lancet is held by the front end portion of the plunger and then the launching spring is compressed by the retraction of the plunger. The protrusion of the plunger causes the rear end of the trigger lever (or the shoulder located at the rear of the trigger lever) to move outward, that trigger lever is constituted such that a force is exerted to act inward (namely on the plunger side), to move outwardly. Then at the instant when the protrusion retracts further by getting over the rear end of the trigger lever (or the shoulder), the rear end of the trigger lever returns inward (the plunger does not retract further). As a result, the protrusion (for example, flange form) engages with or abuts against the rear end of the trigger lever (or the shoulder) while the spring remains compressed (after this state has been achieved, the plunger does not retract further, and preferably unable to retract further) and, substantially simultaneously, opening of the wings is completed.
In this case, when the rear end of the trigger lever has returned inward, “the state of the trigger lever being capable of engaging with the plunger” is achieved, and at the same time, opening of the wings toward outside is completed, and therefore it is unnecessary to cause the rear end of the lancet to retract further. As a result, in this embodiment, “the launchable state” is achieved at the same time as the rear end of the trigger lever has returned inward.
Also in the above further embodiment, it is preferable that at least a portion of the fitting portion of the lancet cap protrudes from the front end opening of the case body when “the state of the trigger lever being capable of engaging with the plunger” correspondingly to “the launchable state” is achieved.
In either embodiment, the wings of the lancet assembly are in the splayed out state when the launchable state” is achieved. As a result, the abutting portions 122 provided on the inside of the wings 116 do not hamper the forward movement of the protruding portion 212 of the lancet body. That is, the lancet body is in a free state in which the restriction on the forward movement is removed. When the state of the engagement or abutment in “the launchable state” is removed by moving the rear end of the trigger lever (or the shoulder) outward after “the launchable state” has been achieved, the launching spring S1 that has been compressed expands instantly. This expansion is utilized so as to launch the lancet body which has been in the free condition as described above while the distal end portion of the pricking member is exposed, and prick the predetermined portion. When the launchable state has not been achieved, on the other hand, the abutting portions 122 provided on the inside of the wings 116 hamper the forward movement of the protruding portion of the lancet body since opening of the wings toward outside has not been completed.
In the state where the loading of the lancet assembly 100 into the injector 300 has been completed as shown in
In one specific embodiment, the wing splaying member is in the form of a pair of wedge-shaped members provided in the injector which members are separated from each other while forming a tapered off shape (decreasing width toward the front end), preferably in the form of a pair of wedge-shaped members that define the sloped surfaces inclined inwardly toward the front end of the injector, front ends of which members can enter the inside of the rear ends of the wings fitted in the sides of the lancet case. When the lancet assembly is inserted rearward through the front end opening of the injector, the distal ends of the rear ends of the wings of the lancet case are positioned so as to come onto the front ends of the wedge-shaped sloped surfaces. As the insertion is continued, the rear ends of the wings slide over the sloped surfaces and, as a result, the force that maintains the wings in the state of folded along the case body is removed so that the wings expand outwardly and this state is maintained. Instead of the wedge-like members, plates may also be disposed obliquely so as to define the similar sloped surfaces.
In the embodiment illustrated, the wing splaying member 340 acts upon at least the rear ends (preferably only the rear ends) of the wings 116, more specifically applies an outward force to the rear end portion of the wing, thereby to expand the wings. More specifically, the wing splaying member may be a pair of wedge-like members 340. The wedge-like members 340 have a shape that tapers off (narrowing toward the front end) while departing from each other and, as a result, define the sloped surfaces 342 inclined inwardly toward the front end of the injector,
It is advantageous to provide the wing splaying member of the wedge shape since it makes possible to automatically expand the wings simply by inserting the lancet assembly rearward. When the wings have expanded in this way, loading of the lancet assembly is completed. Accordingly, it is preferable that the lancet assembly is fitted as predetermined in the injector by the above mentioned “two elements which engage or fit with each other” while the wings are expanded.
As seen from
Thereafter, the lancet cap is normally twisted off (the weakened portion is broken) to expose the distal end portion of the pricking member. Then the trigger lever is operated so as to move the plunger quickly forward, thereby launching forward the lancet body of which distal end portion s exposed and carrying out the pricking operation on the predetermined portion. At this time, the protruding portions of the lancet body passes between the pair of abutting portions 122 of the wings and moves further forward. After pricking, the lancet body quickly moves rearward and the protruding portions of the lancet body stays at a position behind the abutting portions of the wing, thus completing the pricking operation. This process will be described in more detail below.
After the loading of the lancet assembly 100 into the injector 300 has been completed as described above, the lancet cap 206 is removed. In “the launchable state”, it is preferable that at least a portion of the fitting portion 217 protrudes from the front end opening of the case body as described above. The weakened portion is broken by applying forces to the lancet body 204 and the lancet cap 206 in opposite directions around the extending direction of the pricking member (as indicated by the arrow in
In one preferred embodiment, the weakened portion of the lancet can be broken by turning (twisting) the lancet body and the lancet cap in opposite directions around the extending direction of the pricking member. In other words, the weakened portion 208 is designed so as to be broken with such a turning operation. For example, the kind of resin that constitutes the weakened portion and/or a thickness of the weakened portion is selected so as to enable such breaking. After breaking the weakened portion, the lancet cap is brought away from the lancet body, so as to expose the distal end portion of the pricking member from the lancet body.
In one preferred embodiment, in order to enable the rotation around the extending direction of the pricking member during the twisting operation described above, one of an end surface of the front end portion of the lancet body and an end surface of the rear end portion of the lancet cap which end surface opposes to the former end surface has protruding portions, and tops of such protruding portions define a hypothetical flat surface that extends at right angle to the extending direction of the pricking member, and the other end surface defines a flat surface that extends at right angle to the extending direction of the pricking member. In the embodiment illustrated (refer to, for example,
The “hypothetical flat surface” described above is not an actual plane that really exists, but a single imaginary plane that abuts against the tops of the protrusions. Mathematically speaking, a flat surface can be defined by identifying three points that do not lie on one straight line. Accordingly, in the lancet of the present invention, the hypothetical surface defined by the tops of at least three protrusions is perpendicular to the extending direction of the pricking member.
In order to make it easy to twist off the lancet cap 206 by applying such force that causes the lancet body and the lancet cap to turn in the opposite directions around extending direction of the pricking member in the lancet case 102, it is preferable that the lancet body 204 is formed with its cross section of which shape makes it impossible to rotate in the lancet case, while the rear portion of the lancet cap 206 located in the lancet case has a cross section of a shape that enables it to rotate in the lancet case. For example, in the case where the lancet case that accommodates the front portion of the lancet body and the rear portion of the lancet cap has a rectangular cross section, the front portion of the lancet body may have a rectangular cross section that makes it impossible to rotate therein and the rear portion of the lancet cap may have a circular cross section.
More specifically, with considering a cross section perpendicular to the extending direction of the pricking member, the lancet body and the lancet case are constituted such that at least a portion of the wall that defines the inner space of the lancet case is disposed inside the outermost of the trajectories of the lancet body profiles formed by rotating the lancet body around extending direction of the pricking member.
In this case, it is preferable that the lancet case is not formed in a shape symmetrical with respect to the extending direction of the pricking member. In other words, the lancet case is formed in a shape that makes at least a portion of the lancet body impossible to rotate in the lancet case around the extending direction of the pricking member. For example, such a design is employed as a portion of the lancet body that is preferably proximate to the lancet cap, namely the front portion of the lancet body is formed having an oval (or rectangle) cross section perpendicular to the extending direction of the pricking member, and a portion of the lancet case has a cross section (cross section perpendicular to the extending direction of the pricking member) of such a shape that circumscribes the cross section of the lancet body or encircles the cross section of the lancet body with a small gap between the both cross sections (for example, other rectangle that encloses said oval shape (or rectangle shape), other oval located around said rectangle (or oval) or the like).
In contrast, such a design is preferably employed as a portion of the lancet cap that is preferably proximate to the lancet body, namely the rear portion of the lancet cap is formed in such a shape that allows it to rotate around the extending direction of the pricking member. Specifically, a portion of the lancet case is formed in such a shape as an inner wall that defines the inner space of the lancet case is disposed outside of the outermost of a trajectory of said portion of the lancet cap formed by rotating the lancet cap around the extending direction of the pricking member. In this case, it is preferable that said portion of the lancet cap is formed in an axial symmetry shape with respect to extending direction of the pricking member such as a cylinder or a prism, so that said portion of the lancet cap can rotate in the inner space of the lancet case. More specifically, said portion of the lancet cap is formed in a cylinder form or a polygonal prism form, and said portion of the lancet case has such a shape as the cylinder or polygonal prism can rotate inside thereof (for example, a circular cylinder or other shaped cylinder that surrounds the cylinder or polygonal prism).
It is preferable that the inner space of the case body has a cross section perpendicular to the extending direction of the pricking member which cross section does not change significantly, and it is more preferable that the cross section does not substantially change. For example, the cross section of the inner space of the lancet case is formed in a rectangular shape. In this case, for example, the lancet body is formed to have a cross section of other shape (for example, rectangle, square or oval) that cannot rotate within the rectangular inner space, and the rear portion of the lancet cap is formed to have a circular cross section that enables it to rotate within the rectangular inner space.
The lancet comprising the lancet body, the lancet cap and the weakened portion provided therebetween is preferably manufactured by molding a resin with the pricking member being inserted therein (so-called insert molding process) as mentioned previously. This method is advantageous in that it is possible to easily manufacture the lancet in large numbers that comprises the lancet body and the lancet cap that are integrally connected via the weakened portion while the pricking member extends in these members straddling therebetween. The weakened portion is preferably formed by making the thickness smaller in the portion that constitutes the weakened portion among the body of resin that surrounds the pricking member, for example by forming a notch therein. In another preferable embodiment, the weakened portion can be formed by forming an incision in the resin layer (between the lancet body and the lancet cap) that does not reach the pricking member after forming the resin layer that surrounds the pricking member. As to the lancet without the weakened portion, it is preferably produced by the injection molding similarly.
As described above, the launching spring is kept in the compressed state when the in the case where of the plunger engages with the shoulder 330 of the trigger lever. Accordingly, in the state shown in
It is noted that the engaged state can be canceled by depressing the push button 350 inward, which is provided at the front end of the trigger lever. The trigger lever can rotate around a rotary shaft 326. It is preferable to provide a plate-like member 301 that extends from the outer edge of the rear end, such that the plate-like member exerts outward forces on the front portion from the push button and the portion of the trigger lever ahead of the shaft when there is no external force exerted, and an inward forces are exerted on the rear portion behind the shaft of the trigger lever. The state of the push button 350 having been depressed is schematically shown in
In the state shown in
The state at the instant when the distal end portion of the pricking member 210 is ejected from the front end opening 106 of the case body 114 is shown in
A return spring S2 is provided between the in the case where of the plunger 310 and the front partition 344 provided on the inside of the housing. As can be seen by comparing
The state of the lancet body 204 retracting from the state shown in
In such a state as the protruding in the case where of the plunger is fitted in the recess 348 located on the inner edge of the trigger lever (the edge on the side opposite to the side where the push button 350 is provided in the embodiment illustrated) as described above, the protrusion 346 disposed ahead of the recess 348 is constituted such that the engagement would not be canceled even when the plunger 310 receives a force acting forward. Specifically, a rear side surface 347 (refer to
As a result, the shoulder 346 does not lie on the trajectory of the forward movement of the protruding in the case where of the plunger, and therefore does not prevent the plunger from moving forward. The trigger lever is constituted so as to restore the initial state when the force depressing the trigger button 350 is removed.
When such a trigger lever is used, the relationship of the protruding in the case where of the plunger being fitted in the recess 348 of the trigger lever can be maintained even when the lancet case 102 is subjected to a force acting forward by the ejector and the force eventually acts also on the plunger upon discharging the lancet assembly from the injector as will be described later. In order to make sure of this relationship, the front side surface 325 that defines the protruding in the case where of the plunger extends in a direction perpendicular to the moving direction of the plunger or at an angle near such direction as shown in
The perpendicular front side surface and the oblique rear side surface that define the protruding portion 324 the plunger, and the oblique front side surface and the perpendicular rear side surface that define the protrusion 346 disposed on the inner side of the trigger lever described above are combined so that protruding portion 324 of the plunger can easily get over the protrusion 346 of the trigger lever and move rearward. However, once get over thereafter, the protruding portion of the plunger cannot easily get over the shoulder 346 to move forward. In fact, at least one of the shoulder 346 and the protruding portion 324 must be deformed or broken in order to get over.
Thus in one embodiment of the injector of the present invention, the trigger lever has a bump or a recess provided ahead of the rear end (or the shoulder) on the inner side thereof, and the protrusion of the plunger abuts against the rear end of the bump of the trigger lever or is fitted in the recess before loading the lancet assembly or after launching the lancet. In other embodiment, the trigger lever may have both of a bump and a recess disposed adjacent to each other as shown and, in this case, the protrusion of the plunger fits in the recess while abutting against with the bump. In the state where the plunger is fitted in, the plunger cannot move even when a force is exerted in the direction of moving the plunger forward. However, when a force is exerted in the direction of moving the plunger rearward (such as when the lancet assembly is being loaded), it is necessary that the rearward movement is not hampered. For this reason, it is preferable that both the front side surface that defines the bump and the rear side surface that defines the recess define slopes that extend from the trigger lever obliquely rearward, as illustrated.
In one preferable embodiment, the abutting portion of the wing as described above has a form of a protruding portion provided between the front end and the rear end of the wing. In this embodiment, the rear side of the abutting portion of the wing can abut against the front side of the protruding portion of the lancet body and therefore the forward movement thereof can be restricted, when the lancet is inserted into the lancet case and the wings are put into the position along the side of the case body after moving the lancet body rearward relative to the lancet case so as to move the protruding portion of the lancet body to a position behind the abutting portion.
In other preferable embodiment, the abutting portion of the wing as described above defines a step (or shoulder) provided between the front end portion and the rear end portion of the wing, more specifically, the inner wall that defines the wing defines a step h (refer to
The lancet assembly that has been used is discharged from the injector in the following procedure. First, in the state shown in
The stopper 213 is provided on the lancet body for the purpose of preventing the lancet assembly that has been used from being accidentally reused. As will be understood from the foregoing description of the stopper, once the stopper of the lancet body has got out of the rear end opening 107 by moving the lancet case forward relative to the lancet body for closing the wings after the pricking operation, the lancet body cannot enter the lancet case again.
The lancet assembly and the injector are designed so that the inward force closes the wings are automatically applied when the lancet assembly that has been used is discharged from the injector. By such design, a risk related to the distal end portion of the pricking member is substantially eliminated in the lancet assembly that has been discharged. Preferably, a force is applied such that the wall defining the front end opening of the injector when the wing passes through the opening as described below. For example, a distance between partial regions (for example, two points which are opposing to each other) of a profile of the front end opening, particularly a profile of the opening to which the wings are located most adjacently upon discharging is substantially the same as, or a little larger than a distance between the outsides of the pair of the wings, inward forces are applied to the wings by the opening upon passing through the opening, so that the wings are closed.
In one embodiment, it is preferable that the injector further comprises an ejector that is capable of applying a force acting forward on the lancet case that has been inserted. By moving such an ejector forward, a force can be applied to the rear end portion of the lancet case (for example, in the state where the bump 112 disposed on the outside behind the front end of the lancet case 102 has gotten over the bump 304 located on the inside behind the front end opening of the injector and fitted in the injector).
The plunger 352 is configured so that the front end portion 356 abuts or generally abuts against the rear end portion 108 of the lancet case 102 at the time when loading the lancet assembly 100 in the injector 300 is completed. The front end 356 applies a forward force as an acting member to press the rear end portion of the lancet case.
In the case a force is exerted on the rear end portion of the lancet case as described above when the lancet body is grasped by the plunger after the pricking operation, the bump 112 located on the outside behind the front end portion of the lancet cap that has gotten over the bump 304 of the front end opening of the injector and fitted in the injector gets over the bump 304 of the front end opening of the injector, so that the lancet case 102 moves forward relative to the plunger 310, and therefore relative to the lancet body 204 that is grasped by the plunger.
That is, when the state shown in
As described above, the forward movement of the plunger is blocked by the protrusion 346 of the trigger lever and the recess 348. As a result, the force applied by the ejector is used first for moving the lancet case 102 forward. At this time, since the wings 116 move away from the wing splaying members 340 and also the lancet case is passing through the front end opening of the injector, the wings 116 are fitted into the sides of the lancet case in turn.
Then, when the ejector is caused to slide further forward, the stoppers 213 (specifically the base portions thereof) of the lancet body abuts against the inside of the wall that defines the rear end opening 107 of the case body. When the force is increased, the wall that defines the rear end opening 107 of the case body gets over the stoppers 213 due to the shape and elasticity of the stoppers 213. As a result, the stopper 213 protrudes from the rear end opening 107 to the outside.
The state of the stopper 213 having got to the outside is shown in
As described above, when the lancet case 102 moves forward, each wing splaying member 342 does not act on the rear end portion 120 of the wing 1116, followed by the stoppers 213 of the lancet case getting out through the rear end opening 107 of the case body 114. Further, upon gradually getting out of the lancet case 102 while passing through front end opening of the injector, the profile of the front end opening 302 fits the wings 116 into the sides of the lancet case from their front portions in turn.
In order to be fitted into as described above, at least portion profiles of wall portions just beside of which the wings of the lancet case pass of the profile of the wall which defines the front end opening of the injector have to correspond to profiles of side surface of the lancet case which is in the state wherein the wings are fitted into the sides of the case body. That is, the wall portion of the injector which is opposing to the wing has a shape that allows it to contact with the wing of the lancet case which is getting out so as to apply the inward force to the wing. Therefore, the such wall portion is complementary to the side surface of the lancet case in the state wherein the wings are closed of course, the distance between thus opposing wall portions is substantially equal to the distance between the side surfaces of the lancet case in the state wherein the wings are closed.
As a result, the wings splaying outward are fitted into the sides of the case body by the application of the inward forces to the wings by means of the front end opening of the injector without being disturbed by the wing splaying members. Then, the lancet assembly which has been inserted into the injector is discharged by the ejector in the state wherein the wings have been fitted in the sides.
Then, when the ejector is caused to slide further forward, the wall 117 that defines the rear end opening 107 of the case body 114 abuts against the protruding portions 212 located ahead of the stoppers 213. This protruding portions are harder than the stoppers 213, and do not have the flexibility of the stoppers 212. As a result, the wall that defines the rear end opening 107 cannot get over the protruding portions 212. That is, the protruding portions 212, unlike the stopper 213, are not capable of getting out of the lancet case. The state of the protruding portions of the lancet body making contact with the wall 217 that defines the rear end opening 107 is also shown in
In the embodiment illustrated, since the stoppers 213 and the protruding portions 212 are located at a small distance from each other, the ejection of the stopper 213 to the outside and the abutment of the protrusion against the wall 217 that defines the rear end opening of the protruding portion 212 take place substantially at the same time.
As will be understood from
When a force is applied so as to cause the ejector to slide further forward in the state described above, the plunger cannot move forward because of the fitting described above, although the force that acts forward is transmitted to the protruding portion 218 of the lancet body grasped by the legs 320 and 322 of the plunger 310. As a result, the front side surface 231 (refer to
Then, when the ejector is caused to slide further forward, the lancet case that includes the lancet body separated from the plunger is discharged through the front end opening of the injector to the outside. The discharging operation is shown in
When the lancet case 102 moves forward, the rear end portions 120 of the wings 116 departs from the wedge member 342, and the wings 116 undergo elastic deformation so as to be positioned on the sides of the lancet case, assuming the state shown in
Thus since the lancet body 204 with the distal end portion of the pricking member 210 being exposed is prevented by the abutting portion 122 from moving forward, the distal end portion of the pricking member is prevented from moving forward beyond a position far inward from the front end opening 106 of the case body 114. It needs not to say that the protruding portions 212 of the lancet body 204 or the protruding members 232 are also not capable of getting rearward out of the rear end opening 107 of the case body 114. In this way, when the lancet case 102 moves forward and the wings 116 are fitted in the lancet case, the lancet body is held within the lancet case 102 with the distal end portion of the pricking member located at a position sufficiently rearward from the front end opening 106.
As will be easily understood from
It is preferable that the lancet case and the lancet body have means of making it smoother for the lancet body 204 to move in the lancet case 102 during pricking. The means may be, for example, the protruding member 215 of the lancet body described above. The channel 135 is defined by a pair of rails 140 provided on the inside of the side surface of the lancet case 102 so as to sandwich such protruding portion described above. Guiding means that makes it smoother for the lancet body 204 to move in the lancet case 102 can be constituted by combining such a protruding portion described above and the rails.
The lancet assembly and the injector of the present invention described above are formed from resin except for the pricking member and the springs, and particularly preferably formed by molding of resin. In addition to the ease of manufacturing, elasticity of resin can be preferably utilized in the function of the wings, the function of the stopper, a function of the plunger legs, and the fitting operation when loading the lancet assembly into the injector (for example, the relationship between the protruding portion of the lancet case 112 and the bump 304 at the front end opening 302 of the injector).
It is preferable that the injector has a mechanism that controls the depth of pricking. The injector of the present invention has a pricking depth adjusting drum disposed behind and adjacent to the rear partition in the injector housing. The plunger extends and terminates within the drum. The drum has a ring-shaped member that is capable of rotating around the plunger and that is secured on the inside at the front end of the drum. The length of the ring-shaped member in the pricking direction changes along the circumferential direction thereof, and preferably changes continuously or stepwise. The rear end of plunger has a hitting member that strikes the rear end surface in a portion along the circumferential direction of the ring-shaped member. When the plunger moves forward for pricking, the hitting member on the rear end of plunger strikes a portion of the rear end surface of the ring-shaped member in the drum, and is therefore unable to move further forward. The object which the hitting member provided on the rear end of the plunger strikes can be changed from said portion of the rear end surface of the ring-shaped member to the other portion by causing the ring-shaped member to rotate around the plunger by means of the drum rotation. As a result, it is made possible to change the position of the rear end of the plunger with respect to the pricking direction upon hitting the portion of the rear end surface of the ring-shaped member by the rear end of the plunger.
When the position of the rear end of the plunger relative to the pricking direction changes as described above, a length of a rear portion of the plunger which portion extends behind the rear partition changes. Since the length of the plunger itself is fixed, the change in the position of the rear end of plunger means a change in the length of a front portion of the plunger which portion extends ahead from the rear partition, hence a change in the distance between the rear partition and the distal end portion of the pricking member that protrudes from the lancet body grasped by the plunger. In the meantime, since the distance between the rear partition and the front end opening of the case body is fixed, the length of the distal end portion of the pricking member protruding beyond the front end opening of the case body, namely the depth of pricking changes.
It is preferable to provide a cap-like knob that can be fitted in the circumference of the drum, so that the drum can be turned easily from the outside of the injector. The portion of the rear end surface of the ring-shaped member which is hit by the hitting member can be selected by turning the knob.
With reference to the drawing that depicts the injector described above, for example
In the embodiment shown in
As a result, the hitting member 367 is allowed to strike the end surface 395 having a length a2 in the pricking direction, and the hitting member 367′ is allowed to strike the end surface 398 having a length a2, in the pricking direction.
As will be understood easily, as the lengths in the pricking direction of the ring-shaped member which the hitting portion strikes are different, for example the length in the pricking direction is different between step 371 and step 373, the distance over which the plunger can travel forward, namely the pricking depth changes. In this way, the pricking depth can be controlled by causing the hitting portion to strike other portion of rear end surface of the ring-shaped member which other portion has a different length in the pricking direction.
In the case at least one of the hitting member 365 and the ring-shaped member 361 is formed from an elastic material such as a silicone, an urethane or the like so that it has an impact relieving property, the impact generated by these members when hitting can be mitigated. This provides an advantage of mitigating the impact which the user feels upon the pricking operation.
As will be easily understood from the state of the injector after pricking shown for example in
As a result, after carrying out the pricking operation, or in the case the pricking operation was a failure for some reason (for example, when the lancet was launched before applying a finger tip to the front end of the lancet case), the launchable state can be resumed by pulling back the drum 360 (hence the knob 366), if the lancet assembly is loaded, namely when it has returned to the state as shown in
Thus it is preferable that the injector of the present invention is designed such that the launchable state can be achieved by pulling back the drum relative to the injector housing so as to move the plunger rearward. Specifically, with the injector that is in the launchable state, it is made possible for the protrusion of the plunger to pass over the rear end 330 of the trigger lever by pulling back the drum so as to move the plunger rearward. At the instant when the protrusion has passed over the rear end, the trigger lever moves inward, and the lancet becomes able to be launched again.
When the drum is pulled rearward in order to retract the drum as described above, a force that turns the drum may also be exerted, which may accidentally turn the drum around the pricking direction and cause inadvertently setting the pricking depth to an undesirable value. In order to prevent such an unintentional change of the pricking depth, it is preferable that the drum has a rotation limiter located ahead of the rear partition. The rotation limiter comprises a first cylindrical portion that is located ahead of the drum while passing through the rear partition and a second cylindrical portion located ahead of the first cylindrical portion. The plunger passes through the drum rotation limiter and extends in the drum. The drum can move along the longitudinal direction of the plunger together with the drum rotation limiter. It is preferable that the first cylindrical portion can rotate in the opening of the rear partition, but the second cylindrical portion cannot rotate in such opening.
Such rotation limiter can be formed by fitting the rotation limiting member 380 in the connection 382 that extends forward from the drum 360 that is composed of the drum forming components 364 shown in a schematic perspective view of
The second cylindrical portion has, for example, a profile of an equilateral polygonal shape and the opening has an equilateral polygonal shape that circumscribes the former equilateral polygonal shape or surrounds the equilateral polygonal shape with some gap between them, and the first cylindrical portion has a cross section of a shape that can turn within the opening of the equilateral polygonal shape (for example, circular, oval or equilateral polygonal shape).
In the embodiment illustrated, the second cylindrical portion 386 having a profile of equilateral decagon with the corners chamfered, the chamfered portion denoted as 388. The opening of the rear partition has an equilateral decagonal shape that circumscribes or surrounds, with keeping some distance, the former equilateral decagonal shape, and the first cylindrical portion 384 has a circular cross section that can turn within the opening of the equilateral decagonal shape.
Providing the rotation limiter makes it possible to prevent the inadvertent rotation of the drum due to the second cylindrical portion being disposed in the opening of the rear partition when the drum is moved or pulled rearward relative to the injector for the purpose of charging the injector again. The length L of the first cylindrical portion in the pricking direction is at least substantially the same as the thickness of the rear partition and preferably the same as or a little larger than the thickness of the rear partition. There is not restriction on the length of the second cylindrical portion.
When pulling the drum rearward, it is preferable to compress a spring, and the expansion of the compressed spring is utilized when the pulling force is removed, thereby causing the drum to automatically return to its original position. Specifically, the spring may be disposed around the drum rotation limiter at a position ahead of the rear partition. More specifically, for example, the return spring S3 may be disposed between the rear partition and the flange 390 provided at the front end of the second cylindrical portion.
It is noted that the present invention provides the lancet and the lancet case that constitute the lancet assembly of the present invention described above, the kit of the lancet and the lancet case for constituting the lancet assembly of the present invention described above, the pricking device composed of the lancet assembly of the present invention described above and the injector of the present invention described above, and the kit of the pricking device constituted from the lancet assembly of the present invention described above and the injector of the present invention described above.
The lancet, the lancet case and the lancet assembly constituted from these members and the injector of the present invention provide a safer and convenient device.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-163498 | Jun 2006 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/061804 | 6/12/2007 | WO | 00 | 4/14/2009 |
