The present invention relates to a lancet assembly which comprises a cassette including a lancet and a lancet ejecting device. Such assembly ejects the lancet, and thus it is also referred to as a “lancet ejecting assembly”. Such assembly can be used for obtaining a small amount of blood from a predetermined portion (for example, a tip of a finger) of a human, an animal or the like. In a preferable embodiment, the cassette comprises a sensor for blood glucose level measurement, and the lancet ejecting device comprises a unit for blood glucose level measurement, so that the assembly according to the present invention allows both of blood collection and blood glucose level measurement of collected blood.
A blood glucose level measuring system is currently used wherein a small amount blood collecting device (that is, a lancet and a pricking device) and a blood glucose level measuring device for collected blood (that is, a sensor and a blood glucose level measuring device), which two devices are separate from each other, are to be used in combination so as to measure a blood glucose level of a diabetes patient.
For example, Accu-Chek Comfort from Roche (Switzerland), One Touch Ultra from Lifescan (U.S.), Dexter ZII from Bayer (Germany) and Dia-Meter α from Arkray (Japan) are commercially available as the blood glucose level measuring device. With the blood glucose level measuring system in which the above described blood glucose level measuring device is used, another separate small amount blood collecting device is required, and such system is mainly used domestically. As such separate small amount blood collecting device, Softclix and Softclix lancet from Roche, One Touch Ultra Soft and One Touch Ultra Soft lancet from Lifescan, Microlet and Microlet lancet from Bayer and Multilancet II and Multilet are commercially available.
In hospitals, blood glucose level measurement is performed as to general public patients, and there is a risk that an amount of blood having been deposited to a pricking device upon blood collection of a previous patient may attach to a pricking portion of a next patient, so that the next patient may be subject to an infectious disease (such as AIDS, hepatitis B, hepatitis C or the like) by virute of this attached blood. Due to such situation, a single use safety lancet which cannot be reused is used for blood collection as a pricking device. Measurement of a blood glucose level is performed using the blood glucose level measuring device as described above.
Recently, measurement of blood glucose level is required in animal hospitals. Since there is no commercially available system which is specific for animals, the small amount blood collecting device as described above is used for the animals.
In the above mentioned prior art, the two devices, namely the device for blood collection and the device for measurement are required, so that the measurement requires a large amount of labor, and as to conveniences of such operationality, portability or the like, those devices are not completely satisfactory.
For example, when a blood glucose level measuring system is used in which a blood glucose level measuring device such as One Touch Ultra from Lifescan as well as a small amount blood collecting device such as One Touch Ultra Soft and One Touch Ultra Soft lancet from Lifescan are used in combination, the following operations are required:
for preparation of blood collection using the blood collecting device, (1) preparing a pricking device, (2) removing a front cap from the device, (3) fitting a lancet into a lancet holder of the device, (4) twisting off and removing a needle tip shielding cap from the lancet, (5) placing on the pricking device the front cap which has been removed, and (6) pulling a cocking lever of the pricking device backward to be for a ready state; and
also, for preparation of measurement using the measuring device, (7) preparing a measurement sensor (i.e. test paper), and (8) inserting the sensor into the measuring device;
then, (9) taking up the pricking device which is in the ready state, (10) holding a blood collection portion against a tip portion of the pricking device, (11) pressing a lancet ejecting button so as to eject the lancet and piercing the blood collection portion, (12) confirming bleeding and putting the pricking device, (13) spotting an amount of bleeding blood on the sensor in the device, (14) reading an indicated measurement, (15) removing the sensor from the device and disposing the sensor, and (16) returning the measuring device to its original state;
as to the pricking device, (17) removing the front cap, (18) placing a safety cap on the lancet which is fitted into the lancet holder, (19) removing the lancet from the lancet holder and disposing the lancet, (20) placing the front cap on the pricking device, (21) returning the pricking device to its original state.
A system is commercially available which intends to alleviate the above described problem as to convenience. For example, Soft Tact from Abbott (U.S.) and Medi-Safe eZ from Terumo (Japan) are commercially available. These systems allow blood collection and measurement to be performed in a single unit so that convenience is improved. However, in these systems, the pricking device and the measuring device are merely mechanically integrated.
Apart from such systems, WO02/56769 discloses a unit in which a sensor includes a lancet therein, and such sensor is integrated with a blood glucose level measuring device. With this unit, there is a possibility that a needle is accidentally exposed from a front end of the sensor after using the lancet, which causes a safety related problem.
It is therefore desirable that a lancet assembly is provided which is further improved in terms of its operability, convenience and safety.
The present invention provides a lancet cassette comprising a lancet which includes a pricking member for piercing a predetermined portion, and a container which defines a space therein where the lancet moves, characterized in that
the lancet cassette is capable of mounting a thin sensor element thereon, and
a moving direction of the pricking member of the lancet intersects with an extending plane of the sensor element in the vicinity of a leading end of the sensor element.
Also, the present invention provides a lancet assembly comprising the lancet cassette as described above and a lancet ejecting device which comprises a lancet ejecting member and ejects the lancet, and the pricking member pierces the predetermined portion.
In addition, the present invention provides the lancet ejecting device which forms, in combination with the lancet cassette as described above, the above described lancet assembly.
In the present specification, the terms “front” and “rear” as well as the phrases which substantially include meanings of such terms (for example, “forward” and “front end”, and “backward” and “rear end”) are used based on a direction along which the lancet moves so as to prick (or pierce) the predetermined portion (which is also hereinafter referred to as a “pricking direction” corresponding to a direction indicated with arrow A in
Also, in the present specification, the terms “up(per)” and “low(er)” as well as phrases which substantially include meanings of such terms (for example, “upward” and “upper side”, and “downward” and “lower side”) are used based on the horizontal plane as described above unless otherwise mentioned.
The present invention will be hereinafter explained in detail, and merely for a purpose of easily understanding, reference numbers are given to concrete features which correspond to elements constituting the present inventions, but it is to be understood that such reference numbers do not intend to limit the elements which constitute the present inventions to such concrete features.
In the drawings, the reference numbers indicate the following elements:
In a first aspect, the present invention provides a lancet cassette 104 (which is also referred to as merely a “cassette”) comprising a lancet 100 which comprises a pricking member 106 (which may in the form of for example a needle or a blade, and preferably the needle) as well as a container 102 for the lancet. The lancet is substantially composed of the pricking member 106, a lancet body 108 and a shield member 110. The lancet body 108 and the shield member 110 are connected together through a weakened portion 112 in the lancet which has not been used. The pricking member 106 is enclosed with the lancet body 108 and the shield member 110. It is noted that the lancet is preferably produced by injection molding while the pricking member like a needle is inserted as described below, and in such case, a portion of the pricking member may be exposed because of production convenience. For example, a portion of the pricking member is exposed in a space 114 in
For a purpose of pricking, when a force is applied so as to separate the shield member from the lancet body (as shown for example with arrows in
The container defines a space wherein the lancet moves while its tip portion is exposed so as to prick a predetermined portion. That is, the lancet moves in the space toward the predetermined portion with the tip portion of the pricking member being exposed, followed by pricking the predetermined portion and then this exposed pricking member is held within the space of the container.
A sensor element 118 can be mounted on such container, which element is able to perform a predetermined measurement (for example, blood glucose level measurement) as to blood which bleeds from a pricked portion. The sensor element is of a thin type as shown in
As a concrete sensor element, a blood glucose level measuring sensor element may be exemplified such as Dia-Sensor (trade name) commercially available from Arkray or AutoDisc sensor (trade name) commercially available from Bayer. It is obvious for those skilled in the art that the above described blood glucose level sensor is merely an example, and sensors may be used which are for measurement items (such as a cholesterol level) other than the blood glucose level.
Various types of such sensor elements are commercially available, in which there is a device to absorb a body fluid to be measured from its front end to its thin layer portion of the agent. Usually, such sensor element can perform a predetermined measurement by depositing a body fluid to be measured to its front end.
The above sensor element can be mounted on an outer surface or an inner surface of an upper wall of the container which defines the space where the cassette moves. Thus, in one preferable embodiment of the present invention, the cassette comprises the sensor element 118 which performs a predetermined measurement as to blood, for example a so-called biosensor element.
In one embodiment, container 102 is comprised of an upper half 202 and a lower half 204, and the upper half forms an upper wall on which the sensor element can be mounted. That is, the sensor element is located on an outer surface or an inner surface of the upper wall. It is noted that in an embodiment shown in
In the present specification, with regard to the terms “up(per)” and “low(er)” and also the phrases related thereto which substantially include meanings of such terms (for example, “upward”, “upper side”, “downward” and “lower side”) as well as the terms “outer” and “inner” and also the phrases related thereto which substantially include meanings of such terms (for example, “outside” and “inside”), these terms are used based on the cassette and a lancet ejecting device, which are in their assembled states.
In one embodiment, the lancet cassette according to the present invention comprises the sensor element on its outer surface of its upper wall 207 and, the front end 120 of the sensor element is located close to a front end 206 of the container, preferably above its frontmost end or a vicinity thereof. In another preferable embodiment, the front end 120 of the sensor element may be retracted a little from frontmost end 209 of the container as shown in
Upon pricking the predetermined portion, when the front end 206 of the container is forced against the predetermined portion, a part of the predetermined portion enters somewhat inside from the front end 206. Thus, there is substantially no difference between a case where the front end 120 of the sensor element is retracted a little from the frontmost end of the cassette and a case where the front end 120 of the sensor element is located above the frontmost end of the container.
When the sensor element is located as described above, a distance between an amount of bleeding blood and a sample intake port of the sensor element becomes short, so that an amount of the bleeding blood is likely to be in contact with the sample intake port. In another preferable embodiment, the sensor element is placed on inner surface 201 of the upper half 202. In this case, the distance between an amount of bleeding blood and the sample intake port of the sensor element becomes shorter, so that an amount of the bleeding blood is more likely to be in contact with the sample intake port.
In another embodiment, the cassette does not have such sensor element, and in this case, a user mounts the sensor element onto the cassette before using the lancet for pricking, particularly on the outer surface or the inner surface of the upper half.
As to the cassette according to the present invention, a moving direction of the pricking member of the lancet intersects with an extending plane of the sensor element in the vicinity of a leading end of the sensor element.
The “extending plane of the sensor element” means a hypothetical flat surface which includes a main surface of the sensor element 118 which is of a flat thin type. Such flat surface 130 is schematically shown in
Clearly seen from
In another embodiment a front end portion of the sensor element 118 is set back in its center, for example as shown in
Basically, the position of intersecting point 138 may be shifted by changing an angle α formed by the pricking direction A and the extending plane B. Provided that the lancet and the container are not changed except for angle α, the intersecting point is shifted backward when this angle is increased and shifted forward when the angle decreased. When pricking direction A and extending plane B are parallel to each other (that is, angle α is 0°), pricking is likely to happen at an angle of 90° relative to the predetermined portion, but a distance between the front end of the sensor element and an amount of bleeding blood is long. When angle α is set greater than 0°, pricking direction A intersects with extending plane B.
The cassette according to one preferable embodiment of the present invention is configured such that an amount of bleeding blood after pricking is able to be in contact with the front end of the sensor element, namely, the intake port, so that the blood is supplied into the sensor element so as to perform a predetermined measurement without an additional operation after pricking. In other words, the “vicinity of the front end of the sensor element” in this embodiment means an area of the extending plane which allows an amount of the bleeding blood after pricking to be present at the intake port. Generally, the vicinity of the front end means an area of the extending plane located in a range from 3 mm behind the front end of the sensor element up to 10 mm ahead thereof, preferably in a range from 2 mm behind the front end of the sensor element up to 8 mm ahead thereof, and more preferably in a range from a position just at the front end of the sensor element up to 7 mm ahead thereof. When referring to such range, the moving direction of the pricking member is based on a central axis of the pricking member, and the extending plane is based on the lower surface of the sensor element.
The present invention, however, does not exclude an embodiment of the cassette wherein an amount of bleeding blood is more or less away from the intake port, which requires an additional operation after pricking so as to make an amount of bleeding blood be in contact with the intake port, and this embodiment is less preferable. In such embodiment, the moving direction of the pricking member of the lancet intersects with the extending plane in an area except the vicinity of the front end of the sensor element; that is, intersects in an area which is separated forward by a distance of more than 10 mm from the front end of the sensor element. Such distance is preferably not longer than 20 mm and more preferably not longer than 15 mm. An embodiment which requires an additional operation upon pricking can be generally discriminated from the embodiment which requires no additional operation upon pricking by the area of the vicinity of the front end as described above. Such discrimination is a kind of measure but not absolute. Thus, even when the same cassette is used, an additional operation may be required or not required depending on, for example, an angle of the predetermined portion relative to an opening at the front end of the cassette when pricking, an amount of blood which bleeds out by pricking or the like.
Recently, a thickness of the pricking member tends to be smaller for a purpose of alleviating pain of users. Therefore, an amount of blood which bleeds by pricking has become smaller, so that it is not easy to identify a pricked position. Particularly, a diabetic patient sometimes has bad eyes, and it may often not be so easy to make an amount of blood be in contact with the front end of the sensor element. By using the cassette according to the present invention, no additional operation becomes required as described above, which is very convenient to the diabetic patient.
When angle α is large, which is formed by the moving direction of the pricking member and the extending plane of the sensor element, an incision may be larger since pricking is performed at a substantially slant relative to a surface of the predetermined portion (for example, a skin surface of a finger tip). Therefore, an excessively large angle α is not preferable. In the present invention, angle α is preferably in a range between 2° and 10°, more preferably in a range between 3° and 8°, most preferably in a range between 4° and 5°, and for example 4.5°. This angle means a smallest angle defined by a plane and a straight line which intersects with the plane (i.e. a pricking direction). When such angle is excessively large, the angle which is formed by the surface of the predetermined portion to be pricked and the pricking direction is excessively away from 90°, so that an incision formed in the predetermined portion by pricking may become larger, which may cause more pain. Also, a thickness of the container which will be described below becomes larger, and a volume of a packaged cassette as an article is large, which is not preferable from viewpoints of, for example, packaging and transportation of the lancet assembly. On the other hand, when the angle is excessively small to be close to 0°, the distance between the intake port of the sensor element and the pricking position becomes excessively long, so that it is possible that an amount of bleeding blood cannot be in contact with the intake port of the sensor element after pricking.
In order that the lancet is moved obliquely upward as described above, the container is designed so that an inner surface of the lower half 204 of the container guides the lancet forward and obliquely upward. Since inner surface 215 of the lower half of the container in fact supports the lancet, the lower half is designed such that the inner surface 215 of the lower half of the container entirely extends forward and obliquely upward. In an embodiment shown in
Generally, it is preferable to design such that the inner surface of the upper half and the inner surface of the lower half are substantially parallel to each other. Therefore, when the container which houses the lancet is viewed from its side, a flat surface of the container (i.e. outer surfaces of the upper half and the lower half) extends horizontally while the lancet is contained in the container such that it extends forward and obliquely upward relative to this horizontally extending surface.
The lancet according to the present invention is substantially flat as a whole as seen from
The lancet 100 is substantially comprised of the pricking member 106, the lancet body 108 and the shield member 110, and the pricking member 106 is in the lancet body 108 and the shield member 110. In a state before use of the lancet, most of the lancet body 108 except a portion thereof is contained in the container 102 as described below. The shield member 110 comprises a tab portion 150 and a cap portion 152, which is contained in the container. The cap portion 152 covers the tip portion 116 of the pricking member while being present around the tip portion 116, so that the tip portion is shielded (or sealed or blocked) against its ambient environment. The tab portion 150 facilitates a user pinching and pulling off the shield member 110 so as to separate the shield member 110 from the lancet body 108.
The container 102 is formed by connecting the upper half 202 and the lower half 204, which are connected while they are opposed as described above, and the above explained lancet 100 is housed in a space defined by the container while it is able to be ejected. The container 102 includes an opening 208 at its front end 206 and an opening 212 at its rear end 210, and it is formed by connecting the upper half and the lower half together while they are opposed to one another. This connection may be performed in any appropriate manner. For example, an adhesive or a screw may be used. In a particularly preferable embodiment, the upper half and the lower half are connected by means of press fitting. For example in
From a viewpoint of production convenience, it is preferable to produce a container preform 220 in which the upper half 202 and the lower half 204 are connected together by a hinge portion 218 located between sides thereof. The preform may be produced by for example injection molding. The upper half and the lower half are connected together by folding the preform around the hinge portion. For such connection, it is preferable that posts (or small columns) 214 and holes 216 into which the posts are press fitted are provided to the halves, respectively.
The lancet having the pricking member of which tip portion 116 is exposed is ejected by a trigger member as explained below. Once ejected, the lancet is able to move forward and backward before and after pricking the predetermined portion in the space 222 defined by the upper half and the lower half, but it is substantially not able to move in other directions. Thereby, the lancet is surely ejected as predetermined. It is noted that prior to starting ejection, the lancet is engaged with the container so that movement of the lancet is limited and it is substantially not able to move as described below.
As to the lancet 100 which is able to move as explained above, the pricking member 106 (for example, a needle or a blade, and preferably the needle) is enclosed by the lancet body 108 and the shield member 110 in its unused state. Such lancet is preferably produced by insert molding of a resin (for example, a polyethylene resin (such as HDPE, LDPE and the like), a polypropylene resin, a nylon resin, a polyacetal resin, a polystyrene resin, and various copolymers of monomers for the above mentioned resins) so as to integrate the lancet body 108 and the shield member 110. Upon the insert molding, a border portion between the lancet body 108 and the shield member 110 may be made to have a small thickness around the pricking member 106 so as to form a notch portion which corresponds to weakened portion 112.
It is preferable that weakened portions 112 are produced while exposing a portion of the pricking member 106 around its entire periphery between the lancet body 108 and the shield member 110 by forming resin portions on either side of this exposed portion in which resin portions notches are provided, respectively. That is, the resin portions are formed to define a space 114 in which the portion of the pricking member 106 is exposed. When the portion of the pricking member is not exposed, a force required to break the weakened potion become excessively large.
Such notches are formed by inserting opposing blades vertically into a resin portion at predetermined positions thereof on either side of the exposed pricking member as if the blades sandwich the resin portion. For example, the blades (such as razors) are inserted into the resin portion from its top and bottom (or its left side and right side), respectively, so as to form the notches. It should be noted that some of the resin portion has to remain intact such that pulling off of the shield is possible as described later. Generally, the notches are formed such that a thickness of the resin portion between a bottom of one notch and a bottom of an opposing notch is preferably 0.02 mm to 0.2 mm, for example about 0.06 mm.
In an embodiment other than the embodiment wherein the notches are provided on both sides of the exposed pricking member portion, a weakened portion which separates the lancet 100 into the lancet shield member 110 and the lancet body 108 is formed of a resin in the form of a thin layer which is located around a portion of the pricking member which connects the lancet shield member 110 and the lancet body 108. Such thin resin layer surrounds the pricking member portion and it preferably comprises reinforcing portions in the form of wings which extend horizontally and vertically relative to the extending direction of the pricking member (i.e. a direction parallel to the direction shown with arrow C in
The above described weakened portion is illustrated in
The lancet body 108 further comprises a lancet rear end 142, lancet hook portions 144 on either side of the lancet rear end, and lancet pullout preventing portions 146 each located in front of the lancet hook portion. Before using the lancet, the lancet rear end 142 protrudes outward from the opening 212 of the rear end 210 of the container 102, and also the lancet hook portions 144 protrude outward from the opening 212 of the rear end 210 of the container 102 and are adjacent to and engaged with an exterior outside of the rear end 210 of the container. The lancet pullout preventing portions 146 are located in the space 222 within the container while being adjacent or near an interior of the rear end 210 of the container 102.
After ejection of the lancet, the lancet rear end 142 and the lancet hook portions 144 are located in the space 222 of the container. The lancet body 108 further comprises retracting portions 148 which move the lancet backward after having moved forward in the container and pricked as described below. Various portions (142, 144, 146 and 148) which the lancet includes are preferably formed integrally with the lancet body 108. For example, the above mentioned insert molding can produce a lancet body which is integrated with the various portions as well as which is simultaneously integrated with the shield member.
It is noted that the above described container 102 in which the lancet 100 is housed is called the “cassette” regardless of whether it is in a state after or before the lancet has been used. As shown in
In a second aspect, the present invention provides a lancet assembly which is comprised of the lancet cassette comprised of the above described lancet and container which houses the lancet, and a lancet ejecting device, and such assembly ejects the lancet so as to prick the predetermined portion.
In the specification, the term “ejection (or eject)” as to the lancet means that the lancet 100 moves forward by being instantaneously pushed forward of the rear end of the lancet (by a force applied by a spring device as explained below) via the lancet ejecting member 360 (which is also referred to as merely an ejecting member), particularly its leading end 362, and more particularly a protruding portion 364 provided to the leading end while a rear end abuts the ejecting member (see
That is, this relationship is discontinued in any one of the following: (a) in a case when the lancet rear end 142 disengages from the ejecting member 360, particularly its protruding portion 364 so that only the lancet 100 moves forward and protrudes from the opening at the front end of the container so as to prick the predetermined portion; (b) in a case when the lancet 100 moves forward while the lancet rear end 142 is abutting the ejecting member 360, particularly its protruding portion 364 so that it protrudes from the opening at the front end of the container so as to prick the predetermined portion, and then the lancet rear end 142 disengages from the ejecting member 360, particularly its protruding portion 364 during backward movement of the lancet; and (c) in a case when the lancet 100 moves forward while the lancet rear end 142 is abutting the ejecting member 360, particularly its protruding portion 364 so that it protrudes from the opening at the front end of the container so as to prick the predetermined portion and simultaneously with such pricking, the lancet rear end 142 disengages from the ejecting member 360, particularly its protruding portion 364. Since movement of the lancet upon ejecting is extremely rapid, it is substantially impossible to distinguish the above three cases with eyes.
In the case of (a), momentum of a moving lancet may be not completely sufficient for pricking. In the case of (b), a force which moves the ejecting member forward may be applied to the predetermined portion upon pricking, so that a pain upon pricking may increase. Considering these, the case (c) or a case (a′) wherein just prior to pricking, the rear end 142 of the lancet disengages from the ejecting member 360 in the case of (a), is most preferable.
In order to make the case (c) or (a′) possible, an upper edge portion 366 (see
In the present invention, the lancet body 108 comprises the retracting portions 148 as described above. The retracting portions 148 protrude obliquely forward from both sides of the lancet body 108. They are able to elastically deform, and move forward along the pricking direction such that they, preferably their leading end portions hit against collision portions (203 and/or 205) provided on both sides of and inside the upper half and/or the lower half just prior to, substantially simultaneously with or just after pricking the predetermined portion, followed by being deformed, preferably bent.
This above described retracting portion has a function to move the lancet backward after the lancet ejected forward has pricked the predetermined portion. When the lancet intensely moves along the pricking direction, the retracting portions hit against the collision portions (203 and/or 205) and deform due to energy upon hitting of the lancet so as to stop forward movement of the lancet. Immediately thereafter, the retracting portions tend to return to their original forms so as to move the lancet back so that the tip portion of the pricking member is pulled out of the pricked portion and retracted into the container. It is noted that stopping of the forward movement of the lancet and moving backward of the lancet are helped by the pricking member hitting against and pricking the predetermined portion.
The retracting portions in one embodiment are elongated and in the form of wings which extend obliquely forward from both sides of the lancet body as shown in
After pricking, when the lancet is moved back as described above, the lancet hook portions 144 hit against walls as the abutment portions 211 inside the rear end of the container, so that the lancet cannot further be moved backward. Also, when the lancet tries to move forward in the container, it cannot substantially move forward since the retracting portions 148 of the lancet 108 abut against the collision portions 203 and/or 205. Therefore, the tip portion 116 of the pricking member 106 does not protrude outward from the opening 208 at the front end 206 of the container 102. As a result, the rear end 142 of the lancet cannot protrude outward from the opening 212 of the rear end of the container. Therefore, after ejection, the lancet body 108 having the pricking member 106, of which tip portion 116 is protruding, is in a state wherein an entirety of the lancet body is substantially contained in the container 102. Prior to using the lancet (that is, before ejection), the lancet rear end 142 and the lancet hook portions 144 have been exposed outside from the opening 212 of the rear end of the containers 102, but they have not been exposed after the ejection, which differentiates post-ejection and pre-ejection. Thus, whether a lancet has been ejected (thus, whether it has been used) or not is readily seen by confirming with eyes whether or not the lancet rear end 142 and the lancet hook portions 144 are located outside the container.
It is configured that in a state wherein the lancet body 108 is contained in the container 102 after the ejection, even when any force which tries to move the lancet body 108 backward is applied accidentally, the lancet hook portions 144 abut the abutment portions 211 inside and at the rear end of the container, so that the lancet cannot be moved backward any more. For a purpose of such configuration, an angle of the abutment portions 211 relative to the pricking direction is large as shown (for example 30°, 45° or the like), i.e. the angle is to be nearer to 90°.
When the lancet is used, the shield member 110 which is integrated with the lancet body 108 is to be separated from the lancet body 108 as shown in
When the force is applied for the separation, such force to pull out is effectively used to facilitate the separation since the lancet hook portions 144 are engaged with the exterior of the container rear ends 210. Further, the hook portions 144 remain engaged with the rear end 210 so that the protruding tip portion 116 does not protrude outside from the container 102, and is kept retracted from the opening 208 at the front end 206 as shown in
The lancet has to move forward smoothly in the space of the container in a course of being ejected. For that purpose, the lancet has a guide groove 160 on its top side and/or bottom side which is parallel to the pricking member (and therefore, parallel to the pricking direction D), while an inner surface on the upper half 202 and/or the lower half 204 of the container has a protruding portion 230 which can fit into and smoothly move in the groove (and which is preferably complementary to the groove). Such relationship between the groove and the protruding portion fitted therein may be vice versa; that is, the hal(ves) has the groove(e) while the lancet has the protruding portion(s). The protruding portion is preferably elongate as shown in
The cassette above described is fitted into the lancet ejecting device (which is hereinafter also referred to as merely an “ejecting deice”), which leads to the lancet assembly according to the present invention. Using such lancet assembly, the pricking member can prick a predetermined portion. Thus, the cassette can have a function to be fitted into the ejecting device and to eject the lancet contained in the cassette.
Ejecting device 400 comprises the lancet ejecting member 360, a trigger member 370, a stopper 372 and a connector 374, which are contained in a housing 700 (see
In order to apply the forward force to the ejecting member as described above, an ejection spring 373 is provided, and also in order to apply a backward force to move the ejecting member 360 backward, a return spring 375 is provided, and both of the springs are provided so as to be associated with the ejecting member 360. Further, another return spring 376 is provided while associated with the trigger member 370, which spring applies a backward force so as to return the trigger member 376 to its original position.
The return spring 376 is arranged so as to apply the backward force to the trigger member 370 when no force is applied between the housing and the trigger member. As a result, a flange portion 378 which is located at a rear end of the trigger member 370 is kept in a bias condition by the return spring 376 wherein it is in contact with an interior around an opening 382 at the rear end 380 of the housing. When a force which tries to move the rear end 384 of the trigger member 370 forward is applied to the trigger member (for example, when the rear end 384 is pressed forward by a finger tip), the return spring 376 is compressed, and the trigger member is able to move forward provided that nothing prevents such movement. When such force is released (for example, when the finger tip which is pressing is taken away), the trigger member 370 moves backward since the return spring 376 tends to return to its original form, and the flange portion 378 abuts the interior of an opening periphery of the housing 380.
It is preferable that the return spring 376 is located between the inside of the flange portion 378 of the trigger member and a rear end 379 of a cover member 377 (or a protrusion provided thereon) which is fixed to the housing so as to cover the trigger member 370, so that when a forward force is applied so as to move forward the trigger member 370 relative to the housing, the return spring 376 is compressed, and on the other hand when such a force is released, the trigger member 370 moves backward since the return spring 376 tends to return to its original form.
The ejecting member 360 comprises the ejection spring 373 which is located in front of a partition member 384, fixed to the trigger member 370, as well as the return spring 375 behind the partition member 384. The ejection spring 373 is placed in its compressed condition (from its expanded condition when no force is applied) between the partition member 384 and a flange portion 386 located in a front portion of the ejecting member. The return spring 375 is placed in its compressed condition (from its expanded condition when no force is applied) between the partition member 384 and a flange member 388 located in a rear portion of the ejecting member. When the lancet rear end 142 is abutting the protruding portion 364 at the leading end portion of the ejecting member 360 and moves the ejecting member backward, the trigger member 370 cannot move forward due to a function of a stopper which will be described later, and it is kept substantially unmoved since the flange portion 378 is abutting the rear end of the housing as described above. The partition member 386 is kept in an unmoved state as to the trigger member 370 as described later.
Therefore, in a state wherein the two springs 373 and 375 are placed as described above, when the ejecting member 360 is moved backward by the lancet rear end 142, the flange portion 386 moves backward, but the partition member 384 does not move backward, so that the spring 373 is further compressed (primary compression). By virtue of the spring which is thus compressed and kept in such a compressed state, a least a portion of energy which is required for moving the ejecting member intensively forward upon ejecting the lancet is stored.
To the contrary, since a distance between a rear flange member 388 and the partition member 384 is increased, a compressed state of the return spring 375 is relaxed (but it is still in a compressed state). The return spring 375 is compressed when the ejecting member 360 is moved forward for a purpose of ejection and stores an energy so that it can apply a force which moves backward the ejecting member. As a result, in order that a next cassette can move the ejecting member backward, the ejecting member is moved backward after the ejection.
As shown in
For ejecting, when the rear end 384 of the trigger member 370 is pressed forward, the trigger member 370 is moved forward provided that such movement is not to be prevented by the stopper 372 as described later. When the trigger member 370 is moved forward, the partition member 384 which is fixed to the trigger member 370 is also moved forward, so that the ejection spring 373 is further compressed (secondary compression). By such compression, the spring 373 stores an energy which is required for intensely moving the ejecting member forward upon ejecting the lancet.
With the lancet ejecting device according to the present invention, ejection of a lancet is possible if at least one of the following is available: compression of the ejection spring 373 when a cassette is fitted into the ejecting device so as to move the ejecting member 360 backward (corresponding to the above mentioned primary compression); and compression of the ejection spring 373 when the trigger member is moved forward (corresponding to the above mentioned secondary compression). As described above, in addition to the primary compression, the spring member is preferably arranged such that it is further compressed (the secondary compression) when the trigger member is moved forward by pressing the rear end 384. In this case, the secondary compression of the ejection spring 373 in addition to the compression upon fixing the cassette into the ejecting device (the primary compression) makes a force which is acting on the ejecting member 360 increased so that the lancet is intensely ejected. Alternatively, when the ejection spring is strong, a distance over which the ejection spring is primarily or secondary compressed can be shortened, so that a distance over which the rear end 142 of the lancet moves the ejecting member 360 backward and/or a distance over which the trigger member 370 moves so as to release engagement of the lancet hook portions 144 can be shortened.
A leading end 371 of the trigger member 370 as described above has a function to discontinue an engagement state of the lancet hook portions 144 with an exterior of the rear end 210 of the container 102. The trigger member 370 also has being locked portion(s) 506 behind the leading end(s) 371 thereof, which portion(s) abuts rear end(s) 502 of oblique portion(s) 500 of the stopper 372, and preferably against projection(s) provided on the oblique portion(s). When the trigger member 370 is moved forward, the leading end(s) 371 thereof abuts the lancet hook portions, and when the trigger member is further moved forward, the leading end(s) thereof deforms the lancet hook portions such that those portions approach toward the lancet body.
For a purpose of such deformation, the trigger member is made of a material which is relatively hard and not readily deformed (for example, a hard plastic material such as a polycarbonate). A form of the leading ends 371 is preferably a tapered form or other similar form which diverges forward such that when the leading ends are forced to go over the hook portions after contacting them, the hook portions deform toward a center line (or axis) of the lancet body as a result of the hook portions being made of a more deformable material than material of the trigger member.
In consequence, an engaging state of the hook portions 144 is ended, and the lancet 100 is intensely pushed forward and ejected by the ejecting member since a forward force is applied to the rear end 142 of the lancet by the ejecting member.
As seen from
As shown in
As shown in
The connector 374 further comprises a locating member(s) 532, which has a function to facilitate arranging an electronic device plate 602 as predetermined. The locating member may be in any appropriate form, and it may be in the form of a column as shown. An inside surface of the connector may have a protruding portion 534 which extends along an insertion direction of the cassette so as to facilitate smooth insertion of the cassette. In the shown embodiment, the side wall has two protruding portions on its interior portion. Provision of such protruding portions makes not an entire but a portion of a side surface of the container be in contact with the inside surface of the connector, which helps smooth insertion. The protruding portions may be a series of projections in the form of dots along the insertion direction. Such protruding portion may be provided on only one side surface, and further it may be provided on an inside surface of an upper wall and/or a bottom wall of the container.
Further, a cross section of the cassette which is perpendicular to the insertion direction of the cassette is preferably asymmetric with respect to the up and down direction of the cassette. For example, the cross section has such a shape 536 that only upper corners of the cross section of the connector are chamfered or curved as shown. Correspondingly, the upper half of the cassette is formed such that the cassette has its upper edge portions which correspond to a chamfered or curved shape of the connector. By doing so, the upper side and the lower side of the connector should correspond to the upper side and the lower side of the cassette in order to insert the cassette into the connector.
As to the cassette according to the present invention, the moving direction of the lancet in the container, that is, the extending direction of the lancet is oblique relative to a horizontal plane, so that orientation of the cassette as to its up and down direction upon its insertion is important so as to move the ejecting member backward by the rear end of the lancet. When the cross section of the connector is asymmetric as described above, the up and down direction of the cassette which is able to be inserted is unambiguously defined, so that insertion of the cassette may be tried without confirming its orientation. If the insertion is unsuccessful, then the cassette is turned over and the insertion is again tried, and then the insertion becomes automatically successful so that the ejecting member is moved backward as predetermined.
For a purpose of using the cassette, preparation of use is performed by fitting an unused cassette into the ejecting device so that the cassette is engaged with the ejecting device. In a preferable embodiment, the lancet ejecting device 400 comprises the connector 374 at the opening 542 at the front end 540 of the device as described above, and insertion is performed by fitting the cassette into the connector. In the embodiment shown in
Upon inserting the cassette as described above, when the cassette is moved backward relative to the ejecting device, the lancet rear end 142 which protrudes from the rear end of the container abuts and moves back the leading end 362 of the ejecting member, and particularly its protruding portion 364. After the rear end of the lancet abuts the leading end of the ejecting member, when the cassette is further moved backward so as to fit the cassette, a forward force which tries to move the ejecting member forward (i.e. a force by the ejection spring 373) is applied to the cassette. When the force which tries to move the container backward (for example, a force applied by fingers of a user) is larger than such forward force, the ejecting member is moved backward by the rear end of the lancet. By moving the cassette backward and making it abut the ejecting member regardless of the force thus applied to the ejecting member, the spring is restrained while compressed. This restrained and compressed state of the spring represents that the spring can move the ejecting member forward instantaneously when such spring is put in an unrestrained state (i.e. in a condition under which the spring is able to return to its original form).
When the cassette is moved backward as described above, the engaging portion 510 which is provided in the ejecting device so as to bias to protrude upward is once pressed down, and when the cassette is further moved backward substantially over a predetermined distance from the opening 540 of the front end of the ejecting device, the protruding portion which has been once pressed down is automatically fitted into the concave portion 232 which is formed in the lower half of the cassette, whereby the cassette 104 is engaged with the ejecting device 400 with the ejection spring 373 in a compressed condition. In being fitted as described above, when the connector 374 is provided, the engaging portion 510 fits into the concave portion 232 while passing through the opening 530 of the connector, which finalizes charging the ejecting device with the cassette.
With the lancet assembly according to the present invention, in the above described state wherein the charge with the cassette is finalized, it is preferable that the front end of the lancet cassette which is engaged with the lancet ejecting device protrudes from the front end of the lancet ejecting device, and a distance between those two front ends is at least 7 mm, preferably at least 10 mm and for example 12 mm. Such protrusion prevents an amount of blood which bleeds upon pricking from depositing to the front end of the lancet ejecting device, which prevents an infection problem resulting from blood which is possible when the same lancet ejecting device is used for another patient.
When the lancet ejecting device is not loaded with the cassette, no force is applied to the engaging portion 510 of the ejecting device, so that engaging portion is in a biased state wherein it protrudes into the space of the connector 374 through the opening 530. In a process wherein the cassette is inserted into the space of the connector so as to load it with the cassette, when the rear end of the cassette encounters the engaging portion which protrudes into the space, the rear end 210 of the cassette once presses down the engaging portion 510, regardless of a force which is applied to the engaging portion 510 by the elastic member 512, and the rear end goes over the engaging portion. Then, when the concave portion 232 provided on an outer lower edge of the of the outer half encounters the engaging portion 510 which has been pressed down, the engaging portion 510 automatically goes up, because of no application of a pressing down force to the engaging portion 510, and fits into the concave portion 232 of the container through the opening 530 of the connector, so that an engagement relationship between the cassette and the lancet ejecting device is achieved. The manner thus explained above to achieve the engagement relationship is preferable. Inversely, when a downward force which pushes down the engaging portion is applied to the engaging portion by pressing a discharge button 710, the engaging portion 510 is able to be removed from the concave portion so that the engagement relationship between the cassette and the lancet ejecting device is disconnected.
In a state wherein the container is engaged with the lancet ejecting device as described above, the engagement relationship between the cassette and the lancet ejecting device cannot be ended unless the engaging portion moves downward. Also, in such engagement state, the rear end of the lancet protruding from the opening at the rear end of the container is pushing the leading end of the ejecting member backward. In other words, this state is a state wherein a forward force of the spring is applied to the lancet through the rear end of the lancet.
It is noted that even though the forward force is applied to the rear end 142 of the lancet, the lancet does not move and in its static condition since the lancet hook portions 144 are engaging with an exterior of the rear end 210 of the lancet. Therefore, forward movement of the ejecting member 360 is prevented by the lancet hook portions 144. However, when the engaging condition of the lancet hook portions is discontinued, the lancet 100 and thus the ejecting member 360 becomes in a condition to be able to move forward, so that the force applied by the ejection spring 373 moves the ejecting member instantaneously forward, and also the lancet which is abutting the ejecting member moves instantaneously forward, whereby ejection of the lancet is performed.
The lancet assembly according to the present invention preferably comprises an electronic device 600 which receives electronic signals from the sensor element 118, and processes the signals as predetermined so as to provide and display a converted figure (a blood glucose level) which relates to an intended measurement. An example of such electronic device is one used in a blood glucose level measuring device which processes electric signals from the sensor element to convert them into a blood glucose level. Such electronic device preferably comprises a display which indicates a measurement such as a blood glucose level.
In one embodiment, such electronic device is arranged on the electronic device plate 602, which is placed in the housing. As shown in
Electronic members and electronic circuits (including the display) which calculate and indicate a measurement from electric signals as described above are known, and those known for a blood glucose level measurement can be employed. For example, those used in Diameter a (commercially available from Arkray) as a blood glucose level measurement apparatus can be incorporated as the electronic device into the lancet ejecting device according to the present invention.
As to the ejecting device according to the present invention, the ejecting member is designed such that a moving direction of a leading end of the ejecting member forms an angle with the moving direction of the lancet during ejection of the lancet. As a result, in a process of this ejection, an area where the rear end of the lancet 142 abuts the leading end 362 of the ejecting member gradually decreases, so that an engagement relationship therebetween is finally discontinued as described above. In other words, the ejecting member is designed such that a moving direction of its leading end diverges from the moving direction of the lancet.
For example, an abutment region where the rear end 142 of the lancet abuts the leading end 362 of the ejecting member extends along a thickness direction of the lancet such that the region gradually shifts downward relative to the rear end of the lancet when the rear end of the lancet and the leading end of the ejecting member move forward while keeping an abutment relationship therebetween, and finally the abutment relationship cannot be maintained any more. At a time when maintenance of the abutment relationship becomes impossible, separation of the rear end of the lancet from the ejecting member occurs, so that the lancet is ejected forward, and the leading end of the ejecting member moves forward below a pricking direction. Such abutment region may be with the form of the protruding portion 364 provided on the leading end 362 of the ejecting member.
The embodiment where one moving direction diverges from another moving direction is based on a relative relationship between these two moving directions. As described above, the moving direction of the lancet, that is, the pricking direction, is obliquely upward with respect to the horizontal plane which corresponds to an extending plane of the sensor element. The moving direction of the leading end of the ejecting member is obliquely downward relative to the moving direction of the lancet. Such moving direction of the leading end of the ejecting member may be obliquely upward relative to the horizontal plane, horizontal, or obliquely downward relative to the horizontal plane.
In a particularly preferable embodiment, as shown in
Angle β is preferably from 6° to 20°, more preferably from 10° to 17°, particularly from 12° to 15°, and for example 13°. When the moving directions of the lancet and the leading end of the ejecting member form the angle as described, a discontinuation of an engagement relationship between the rear end of the lancet and the ejecting member becomes easy. Also, the ejecting member is surely moved backward when a cassette containing an unused lancet is fitted into the ejecting device. Further, the ejecting member is surely not moved backward when a cassette containing a used lancet is fitted into the ejecting device.
In addition, the obliquely upward movement of the lancet discontinues the engagement relationship between the rear end of the lancet and the leading end of the ejecting member. It is important to ensure that until such discontinuation, the rear end of the lancet and the leading end of the ejecting member move along the predetermined directions while they are abutting each other. The moving direction of the lancet is ensured by the inner space extending obliquely upward with a predetermined angle, which space is defined by the inner surface 201 of the container upper half and the inner surface 215 of the container lower half as described above. The moving direction of the leading end of the ejecting member is ensured by a guide portion 550 which directs the leading end of the ejecting member along a predetermined direction. In one embodiment, leading end 362 of ejecting member 360 has side protruding portions 367 preferably in the vicinity of or in front of a base portion of protruding portion 364, and the guide portions 550 which are provided on a lower outside surface of the connector 374 move the side protruding portions 367 along a predetermined direction. Each guide portion has an inclined surface which shifts a position of the leading end of the ejecting member downward as the member moves forward.
It is preferable that each side protruding portion 367 is located below the guide portion 550 even though the lancet rear end 142 is maintained abutting the protruding portion 364 of the leading end of the ejecting member. As a result, when the ejecting member moves forward, its leading end 362 moves smoothly, gradually, obliquely, downward and forward on the inclined surface of the guide portion 550.
As described above, the ejecting member is advanced up to its possible front most position and then moved back by the return spring 375 while the ejecting member is moved forward and the lancet is ejected. However, even when the ejecting member has been moved back, the leading end 362 of the ejecting member is preferably located below the above described guide portion 550. In order to facilitate movement of the leading end of the ejecting member 360 as described above, it is preferable to form the ejecting member by providing elasticity to a portion the ejecting member such that substantially only the leading end of the ejecting member can move obliquely downward while the ejecting member as a whole moves horizontally. In order to form such ejecting member, the ejecting member 360 is made of a plastic material (such as a polyacetal resin) and a portion 369 thereof is made thinner so that such portion has the elasticity while a remaining portion is relatively rigid.
It is noted that the lancet rear end does not abut and move backward the leading end of the ejecting member even though a used cassette is fitted into the cassette receiving member through its opening by error, since the lancet rear end 142 is contained inside the container.
The lancet ejecting device according to the present invention comprises a stopper 372 which locks the trigger member. The term “lock” used herein means that the trigger member cannot be moved substantially forward so that the lancet cannot be ejected except when pricking is performed. With the stopper, only when a cassette which contains a usable lancet (that is, a cassette in a state wherein the lancet hook portions 144 and the lancet rear end 142 protrude from the opening 212 at the rear end of the container) is fitted into the ejecting device, a locking state is released, so that it becomes possible to press so as to move the trigger member 370 forward. Concretely, the trigger member 370 can move forward only when the ejecting member 360 is kept in its retracted state by the lancet rear end 142.
The stopper 372 comprises a base portion 560 which is located on the bottom of the housing 561 of the ejecting device, and an oblique portion 562 which is inclined relative to the base portion. As shown in
When the stopper is in its original form as shown in
On the other hand, when the ejecting member 360 is moved backward by the lancet rear end 142, the leading end 362 of the ejecting member moving backward tries to move horizontally and backward. In a case wherein such leading end 362 approaches the rear end 570 of the stopper oblique portion 562 or the vicinity thereof, the leading end of the ejecting member contacts the oblique portion 562 and moves on the oblique portion while applying a downward pressing force (a component force) to the portion. That is, the leading end 362 of the lancet ejecting member applies a force to the oblique portion 562 of the stopper so as to elastically deform the stopper so that the rear end 570 of the oblique portion and the rear end 568 of the base portion which have been spaced from each other approach each other as shown in
In such state, when a force is applied so as to move the trigger member 370 forward, the being locked portion 506 of the trigger member which tries to move forward passes above the oblique portion 562 without colliding with the protruding portion 572 provided on the rear end of the oblique portion since that portion 562 is pushed downward. As a result, thus having passed trigger member 370 is able to release an engagement state of the lancet hook portions.
As clearly seen from the above description, the stopper has to deform elastically, and it may be of any form and made of any material so long as the stopper provides the above described function. In a preferable embodiment, the stopper is produced by molding a resin, and it has a V-shape when viewed from its side as shown in
The lancet assembly according to the present invention is schematically shown in
The lancet ejecting device according to the present invention comprises the lancet ejecting member 360, the trigger member 370, the stopper 372, the connector 374 and the engaging portion holding member 706 as well as other parts associated with those members in the housing 700 which is formed with the housing upper half 702 and the housing lower half 704. In the housing 700, the cover member 377 which covers most of the trigger member 370 is installed on the lower half 740 by press fitting, and the electronic device plate 602 is placed on the cover member. The electronic device 600 is located on the plate 602.
The engaging portion holding member 706 is placed on the elastic member 512 (such as a spring, an elastic form or the like) which is disposed on the lower half 704. The stopper 372 is located behind the engaging portion holding member 706, and the ejecting member 360 is placed such that its leading end 362 is located above the oblique portion 562 of the stopper 372. The ejection spring 373 and the return spring 375 are placed around a rear half portion of the ejecting member 360, and there is provided the partition member 384 between the springs which is movable along the longitudinal direction of the ejecting member. Compression states of these springs depend on a relative position of the partition member 384 which is placed between the flange member 386 located around the center of the ejecting member 360 and the flange member 388 located around the rear end of the ejecting member 360.
Most of the trigger member 370 is located between the walls 392 of the channel portion of the lower half 704 and the exterior of the ejecting member 360 so that the trigger member is able to move back and forth. The rear end 384 of the trigger member protrudes outward from the opening of the rear end of the housing. In order that the trigger member returns to its original state after the rear end is pressed forward, the return spring 376 is placed between the rear end 379 of the cover member fixed to the housing and the trigger member (particularly the protrusion 381 provided on the flange portion 389).
The partition member 384 is fitted into the slits 396 of the trigger member, and forward movement of the trigger member 370 moves the partition member 384 forward so that the spring 373 is subjected to secondary compression.
The connector 374 is placed over the engaging portion holding member 706 and the stopper 372 by press fitting into the front end 540 of the housing 700 such that its openings 530 provided on both its sides are aligned with the protruding portions 510. It is noted that posts 622 provided on the upper surface 620 of the connector 374 pass through holes 624 of the plate 602, so that the plate 602 is located within the housing.
The lancet ejecting device according to the present invention comprises the cassette discharge mechanism, which comprises a discharge slide button 710, an elastic member 712 and a pressing member 714. The button 710 is connected with the elastic member 712 through the upper half 702. Concretely, this connection is achieved by fitting leg portions 716 provided on a lower surface of the button 710 into slits 718 provided on the elastic member 712 which is located below the upper half 702 by, for example, snap fitting. The button 710 thus connected can be moved back and forth in the opening 720 provided through the upper half.
The pressing member 714 comprises leg portions 724 which pass through the openings 722 formed through the plate 602. When a downward force is applied to the leg portions, the leg portions can press the engaging portion holding member 706 downward which is biased upward by the elastic member 512. Such downward force is applied to the pressing member 714 by sliding the button 710 forward so as to move the elastic member 712 forward. For such purpose, the elastic member 712 and the pressing member 714 have inclined surfaces 726 and 728, respectively. These inclined surfaces can contact each other and when the inclined surface 726 is moved horizontally relative to the inclined surface 728 so as to form an angle between these surfaces (that is, moved not parallel to each other), the inclined surface 726 presses the inclined surface 278 downward, so that the pressing member 714 moves downward so as to press the engaging portion holding member 706 downward regardless of the elastic member 512.
In this way, moving the button 710 forward moves the engaging portions 510 downward, so that an engaging state of the engaging portions 510 with the concave portions 232 of the cassette is discontinued, whereby the cassette becomes free; that is, the cassette can be taken out from the device into which the cassette has been fitted. In the shown embodiment, the elastic member 712 has downward protruding members 719 behind the slits 718. As a result, when the slide button 710 is pushed forward subsequently, the downward protruding portions 719 of the elastic member 712 pushes the cassette forward which has become free, so that the cassette which has been fitted into the ejecting device is discharged out of the openings 522 at the front end 520 of the connector.
It is noted that the elastic member 712 has arm form spring portions 730 on both its sides such that their end portions are engaged with the inside of the upper half 702. In the shown embodiment, their end portions are curled, and these curled portions are engaged with projections provided on the inside of the upper half 702. The end portions remain engaged with the projections, so that the spring portions 730 are elastically deformed when the button 710 is moved forward by a force applied by, for example, a finger tip. When such force is released, the elastic member 712 returns to its original form due to elasticity of the spring portions so that the button is automatically moved back.
After locating the plate 602 on the connector 374 and the cover member 377, the pressing member 714 is placed on the plate 602, over which the upper half 702 is placed, so that the ejecting device is completed. It is noted that when various members or parts are placed as described above, any appropriate manner may be used so as to fix them if it is necessary to fix them. In the shown embodiment, press fitting may be used for installation.
The lancet ejecting device 400 which is assembled as described above is schematically shown in a perspective view in
Thereafter, by pulling the tab portion 150 in the embodiment shown in
Then, as shown in
Thereafter, the preform is folded around the hinge portion as shown in
The lancet 100 according to the present invention is schematically shown in
In the present invention, the moving direction of the lancet 100 within the container, and thus the pricking direction is not parallel to the horizontal plane which is defined by the sensor element 118, but the moving direction and the horizontal plane intersect to form angle α. Such state is schematically shown in
A sequence of the lancet moving in the container is schematically shown in
In the state of
As to this intensely having moved lancet 100, its retracting portions 148 hit against the collision portions 205 inside the container and then elastically bend. Such state is shown in
Since these bending retracting portions 148 try to return to their original forms, they decrease momentum of the lancet which is going to prick so as to alleviate impact upon pricking as well as move the lancet backward. Alternatively, when hitting is simultaneous with or after pricking, they move the lancet backward. An anteroposterior relationship in time between hitting and pricking may be any appropriate one. For example, when momentum of an ejected lancet is large, it is preferable that the momentum is decreased a little prior to pricking. When no alleviation of the momentum is required, hitting is preferably simultaneous with or after pricking.
Elastic returning of the retracting portions 148 to their original forms moves the lancet 100 backward, so that the tip portion 116 of the pricking member and the lancet rear end 142 are contained within the container as shown in
A sequence of loading the ejecting member with the cassette is schematically shown in
It is noted that in the state of
From
It is noted that a period after the discontinuation of the lancet hook portions by moving the trigger member 370 forward up to pricking is very short (for example from 6 milli-seconds to 10 milli-seconds), and a change from the state of
In such state, a topmost level of the protruding portions 572 provided on the oblique portion 562 is higher than a bottommost level of the being locked portion 506 of the trigger member 370, and the being locked portion 506 of the trigger member 370 which has advanced is present in front of the protruding portions 572 of the oblique portion (see
Therefore, even when the ejecting device is loaded with a cassette which contains a used lancet, the state shown in
Further, as clearly seen from
Thereafter, the discharge button 710 is moved forward so as to remove the protruding portions 510 out from the concave portions 232 of the container, and the engagement relationship between the cassette and the ejection device is discontinued. Then, the cassette is pulled out of the connector of the ejecting device so as to discharge the cassette.
As explained above, the cassette according to the present invention may comprise a sensor element. Such sensor element may be arranged on the outer surface 207 or the inner surface 201 of the upper half 202 of the assembled cassette. This arrangement may be attained in any appropriate manner. It is noted that the terms “outer surface” and “inner surface” mean a surface which is located outside the upper half shown in
In one embodiment wherein the sensor element is arranged on the outer surface, the outer surface 207 is formed such that it has a base surface 752 as well as side surfaces 754 beside the base surface, which define a concave portion 750 for receiving the sensor element 118. A level difference between the base surface 752 and the side surfaces 754 is preferably at least the same as a thickness of the sensor element. At least a portion of an edge of the side surface 754, which edge is closer to the base surface 752, has an extension 758 which extends above the base surface. The sensor element is put between the base surface 752 and the extensions 758, so that falling off of the sensor element 118 from the outer surface of the upper half is prevented. Therefore, it is preferable that a gap between the base surface 752 and the extension 758 is substantially the same as the thickness of the sensor element, so that the sensor element 118 is firmly held on the outer surface. In this shown embodiment, the sensor element 118 may be inserted from the container end while sliding the sensor element. A state after this insertion is shown in
In another embodiment, the sensor element may be placed from above of the outer surface as shown in
As explained above, in the lancet assembly according to the present invention, the pricking direction of the lancet is not parallel to the moving direction of the ejecting member, and these directions form angle β as shown in
Needles made of a stainless steel (SUS 304) which are conventionally used for lancets were used as pricking members 106. The needles had a diameter of 0.4 mm.
Lancets 100 as shown in
A connection between the shield member 110 and the lancet body 108 was made to be the weakened portion 112 as the notches as shown in the figures, and designed such that by pulling away (that is, pulling off) so as to separate toward opposing directions at the connection, breakage of the connection results. Concretely, a thickness (that is, a thickness of resin around the pricking member) at the notch portion was set at 0.4 mm such that the connection was broken by a force which would be applied when fingertips hold the shield member 110 and the container 102 and separate them (for example, a force of about 0.7 kg to 0.85 kg). A completed lancet had an overall size of 35.2 mm (length)×12.4 mm (width)×2.5 mm (thickness).
The preforms 220 for the container as shown in
It is noted that the container was designed such that angle α is 4.5° in order that the lancet 100 moves obliquely relative to the horizontal plane 136.
After molding of the container, the mold was opened such that the preform extended over the horizontal plane, and the lancet 100 was placed on the lower half 204 of the container such that the hook portions 144 were adjacent to the exterior of the rear end 210 of the container, the lancet rear end 142 protruded from the opening 212 at the rear end of the container, and other portions of the lancet were located within the container. Then, the container was folded around the hinge portion 218 so as to stack the upper half 202 on the lower half 204 and projections were press fitted into small circular holes, whereby the lancet cassette as shown in
Then, the sensor element 118 was placed in the concave portion (that is, on the base surface 752) defined by the step portions (or shoulder portions) formed on the outer surface 207 of the upper half of the lancet cassette. It is noted that the protruding portions 760 formed on the step portions were deformed by an ultrasonic welding machine so as to prevent the sensor element from falling off. This placed sensor element was located in the concave portion as predetermined so that it was not moved even when tried to be moved by a finger.
Since the protruding portions 154 which extended backward from the shield portion 150 remained between the upper half 202 and the lower half 204 immediately inside from the opening at the front end of the container, unity of the shield member 110 and the container 102 was increased. As a result, an operation to fit the cassette into the ejecting device was possible without any problem while holding the shield portion 150 itself without holding the cassette. It was of course possible without any problem to fit the cassette into the connector while holding the cassette after pulling off the shield member 110 from the cassette.
The lancet ejecting device as shown in
Similarly, the following were produced from resin blocks: the cover member 377 (made of an ABS resin), the stopper 372 (made of a polyacetal resin), the connector 374 (made of a polycarbonate resin), the trigger member 370 (made of a polycarbonate resin), the pressing member 714 (made of a polyacetal resin), the engaging portion holding member 706 (made of a polyacetal resin), the elastic member 712 (made of a polyacetal resin), the discharge button 710 (made of a polyacetal resin), the partition member for the ejecting member 384 (made of an ABS resin) and the guide 398 (made of an ABS resin). The guide portions 550 were formed on the connector such that angle β formed by the lancet ejecting member described later and the lancet moving direction was 13.2°.
Similarly to the above preparation for the housing except that a polyacetal resin in place of the ABS was used, the ejecting member 360, the stopper 372 and the flange member 388 were prepared by cutting resin blocks.
It is noted that the engaging portion holding member 706, and the cassette discharge mechanism 710, 712 and 714 were also prepared similarly. As the elastic member 512, a foam made of a silicone foam was used.
The ejection spring 373 had a capacity to provide a force of 565 g, and the return spring 375 had a capacity to provide a force of 270 g. The return spring 376 for the trigger member had a capacity to provide a force of 50 g. All of the springs were made of stainless steel (SUS 304).
The lancet ejecting device 400 as shown in
The cassette 104 of which shield member 110 has not been pulled off was inserted into the connector 374 of the lancet ejecting device 400 while the surface on which the sensor element was placed was upward. When the cassette was inserted over a distance of about 10 mm from the opening 522 of the connector, the rear end 142 of the lancet protruding from the rear end of the cassette abutted the protruding portion 364 provided on the leading end of the lancet ejecting member.
Then, when the cassette was further inserted, the engaging portions 510 of the engaging portion holding member fitted into the concave portions 232 of the cassette, so that the cassette was engaged within the connector as predetermined. Such engaging state means that the ejection spring has been primarily compressed as predetermined. Thereafter, the shield member of the lancet was pulled off so as to finish preparation for pricking. Upon insertion of the cassette, the trigger member 370 was not moved at all.
Next, a finger tip was pressed against the opening 208 of the cassette at its front end, and then the rear end 384 of the trigger member was pressed. While the trigger member was moved forward over a distance of about 5 mm, the ejection spring 373 was secondarily compressed, and at a final stage of such compression, the leading end 371 of the trigger member released an engagement relationship of the hook portions 144 with the exterior of the cassette, so that the lancet 100 was ejected.
As explained above, with the ejecting device according to the present invention, even though only the secondary compression is performed by pressing the trigger member when the lancet is ejected, energy used for the ejection is a sum of energies of the primary compression and the secondary compression. Therefore, the device according to the present invention gives a user of the device an impression that only a little push-in of the trigger member allows ejection of the lancet; that is, the ejection can be easily performed by pressing a button.
The lancet in the cassette was automatically moved back by force of the curved wings 148 to elastically revert back to their own forms (i.e. a spring like force) after pricking, so that the tip portion of the pricking member was located within the container 116, which resulted in a state wherein the needle end did not protrude outward from the front end of the container.
An amount of blood was bled and a portion thereof was deposited to the blood intake port in a spot form which was located at the end of the sensor element, and this deposited blood was taken into the element. Since the front end of the cassette was designated to be located about 8 mm ahead of the front end of the connector of the ejecting device, it was estimated that a possibility that the bled blood deposited to the ejecting device was substantially zero.
After pricking, followed by removing the finger tip from the trigger member so as to return the trigger member to its original form, forward pressing of the trigger member was tried. The being locked portions 506 provided on the leading ends of the trigger member abutted the protruding portions 572 provided on the oblique portions of the stopper, so that forward pressing of the trigger member was impossible. Thus, there was no influence at all due to such trial on the lancet retracted into the cassette. After discharging a spent cassette, the trigger member was similarly pressed, but the above explained locked state was caused as well, so that the trigger member was not moved.
Then, a used cassette was inserted into the connector again and engaged therein by the engaging portions 510. As to the used cassette, a whole of the lancet is contained in the container, and the rear end 142 of the lancet is also located substantially within the container. As a result, the rear end of the lancet was not able to abut the protruding portion provided on the leading end of the ejecting member, so that the projection member was not able to be moved backward, and the stopper remained working. That is, even when the trigger member was tried to be moved forward, it was locked so that the trigger member was not able to be pressed forward.
After discharging the used cassette, a cassette which contained a used lancet was inserted into the connector. During a process of this insertion, the cassette was grasped through a response to fingers through the cassette that the rear end of the lancet abutted the protruding portion of the leading end of the ejecting member, so that the ejection spring was compressed to be in a cocked state, wherein pressing the trigger forward was possible when it was tried. That is, through insertion of the cassette, the rear end of the lancet moves the leading end of the ejecting member backward so that the oblique surfaces of the stopper which lock the trigger member are pressed downward by the cam-like portion provided on the lower side of the leading end of the ejecting member, whereby even when the trigger member is moved forward, the trigger member does not abut the being locked portions. Therefore, in such state, ejection was possible by moving the trigger member forward.
The used cassette was observed. The lancet within the container was automatically retracted by a spring-like effect of the retracting portions provided on the lancet body as the wings, and a frontmost end of the pricking member was located 2 mm behind the opening of the front end of the container, and the rear end of the lancet was inside the opening of the rear end of the container. This state can be said to be the lancet being substantially shielded by the container. In such state, it is prevented as much as possible that an accidental force is applied to the lancet in the container so that the tip portion of the pricking member is exposed outward from the opening of the container at its front end.
Pricking properties of the cassette and the lancet ejecting device were checked. For a comparison, Multi-Lancet II (commercially available from Arkray, needle diameter: 0.4 mm) which was able to set five different pricking depths was used at a pricking depth of “3”. Stacked were twenty sheets of copy paper each having a thickness of 0.075 mm. These stacked sheets were regarded as a skin to be pricked as predetermined by the lancet, and a number of sheets which were pricked was counted.
With the lancet assembly according to the present invention, the number was 7.4 on average, while with Multi-Lancet, the number was 6.9 on average. From these results, it is seen that the lancet assembly according to the present invention has the same pricking properties as those of a commercially available lancet assembly.
It is noted that the present invention includes the following modes (or embodiments):
A lancet cassette comprising a lancet which includes a pricking member for piercing a predetermined portion, as well as a container which has a space therein where the lancet moves, characterized in that
the lancet cassette is capable of mounting a thin sensor element thereon, and
a moving direction of the pricking member of the lancet intersects with an extending plane of the sensor element in the vicinity of a front end of the sensor element.
The lancet cassette according to Mode 1, wherein the vicinity of the front end of the sensor element is any one of an immediate front from the front end of the sensor element, substantially the front end of the sensor element or an immediate rear of the front end of the sensor element.
The lancet cassette according to Mode 1 or 2, wherein a direction of the pricking member of the lancet intersects with an extending plane of the sensor element so as to form an angle between 3.5° to 7°.
The lancet cassette according to any one of Modes 1 to 3, wherein the lancet further comprises a lancet body and a shielding member which are connected through weakened portions with each other, and the pricking member is encapsulated with the lancet body and a shielding member except for a portion which is adjacent to the weakened portions.
The lancet cassette according to any one of Modes 1 to 4, wherein the lancet body comprises a lancet rear end, lancet hook portions located on either side of the lancet rear end, and a lancet pull-out preventive portion located in front of each of the lancet hook portions,
the lancet rear end protrudes outward from an opening at a rear end of the container,
each of the lancet hook portions is located outside and adjacent the rear end of the container and engages therewith,
the lancet pull-out preventive portion is located inside and adjacent the rear end of the container, and
the lancet is housed in the container.
The lancet cassette according to any one of Modes 1 to 5, wherein the lancet further comprises a retracting portion.
The lancet cassette according to any one of Modes 1 to 6, wherein the container comprises the sensor element which is mounted thereon.
The lancet cassette according to any one of Modes 1 to 7, wherein the container is composed of an upper half and a lower half which are connected together with a hinge portion.
A lancet assembly comprises (1) the lancet cassette according to any one of Modes 1 to 8, and (2) a lancet ejecting device which comprises a lancet ejecting member that ejects the lancet.
The lancet assembly according to Mode 9, wherein by fitting a rear portion of the lancet cassette into the lancet ejecting device through an opening at a front end of the lancet ejecting device, the rear end of the lancet abuts a leading end of the lancet ejecting member, then the container is moved back against a forward force acting on the lancet ejecting member so that the lancet ejecting member is moved back, and when the lancet cassette is inserted into the lancet ejecting device over a predetermined length from the opening of the front end of the lancet ejecting device, so that the lancet cassette is engaged with the lancet ejecting device, and so that the lancet cassette is held while a forward force acting on the lancet ejecting device is acting on the rear end of the lancet.
The lancet assembly according to Mode 10, wherein a front end of the lancet cassette which is engaged with the lancet ejecting device protrudes from the front end of the lancet ejecting device.
The lancet assembly according to any one of Modes 9 to 11, wherein the lancet ejecting device comprises a lancet ejection trigger member which releases engagement of the lancet hook portions with the exterior of the rear end of the container,
forward movement of the lancet ejection trigger member substantially releases the engagement of the lancet hook portions with the exterior of the rear end of the container, so that the lancet ejecting member and the lancet of which rear end abuts the lancet electing member instantaneously move forward by the forward force acting on the lancet ejecting member, so that the lancet hook portions and the lancet rear end get into the container in which they move forward, and
The lancet assembly according to any one of Modes 9 to 12, wherein when the lancet ejecting member and the lancet of which rear end abuts the lancet electing member instantaneously move forward, a moving direction of the lancet is forward and obliquely upward relatively to a moving direction of the lancet ejecting member,
The lancet assembly according to any one of Modes 9 to 13, wherein after piercing the predetermined portion, the container receives the lancet such that the rear end of the lancet is prevented from protruding outward from the opening of the rear end of the container,
as a result, when the rear portion of the cassette which includes this received spent lancet is engaged with the lancet ejecting device by inserting it into a lancet ejecting device through the opening at the front end of the lancet ejecting device over the predetermined length, the rear end of the lancet is located above and without abutting the leading end of the lancet ejecting member.
The lancet assembly according to any one of Modes 9 to 14, wherein the lancet ejecting member comprises a stopper which prevents forward movement of the trigger member which initiates ejection of the lancet except when a forward force acting on the lancet ejecting member acts on the rear end of the lancet while the rear end of the lancet is held abutting the leading end of the lancet ejecting member,
the stopper comprises a base portion and an oblique portion which is inclined with respect to the base portion, and front ends of these two portions are connected together while rear ends thereof are separated such that when a force is applied to the oblique portion, the stopper deforms elastically so that the rear end of the oblique portion and rear end of the base portion, which are separated, get closer to each other, and when such force is removed the stopper elastically reverts to its original form,
in a case in which the stopper is in its original form, the rear end of the oblique portion abuts a being locked portion of the trigger member which tries to move forward so as to prevent forward movement,
when the rear portion of the cassette is fitted into the lancet ejecting device through the opening at its front end so that the lancet ejecting member is moved back while the rear end of the lancet abuts the leading end of the lancet ejecting member, the leading end of the lancet ejecting member moved back moves on the oblique portion of the stopper, so that the leading end of the lancet ejecting member applies a force onto the oblique portion of the stopper, whereby the stopper elastically deforms and makes the rear end of the base portion and the rear end of the oblique portion, which have been separated, get closer to each other, and
as a result, the trigger member which tries to move forward is able to move forward while passing over the oblique portion with the being locked portion of the trigger member not abutting the rear end of the oblique portion.
The lancet assembly according to any one of Modes 9 to 15, wherein the lancet ejecting device further comprises an electronic device which performs a predetermined measurement with respect to an amount of blood which bleeds due to pricking.
A lancet ejecting device which forms, in combination with the lancet cassette according to any one of Modes 1 to 8, the lancet assembly according to any one of Modes 9 to 16.
Number | Date | Country | Kind |
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2003-352206 | Oct 2003 | JP | national |
This application is a divisional of U.S. application Ser. No. 10/959,085, filed Oct. 7, 2004, which claims priority under the Paris Convention based on Japanese Patent Application No. 2003-352206 (filed on Oct. 10, 2003, title of invention: lancet cassette and lancet ejecting device, and lancet assembly composed of them). The contents of that application are incorporated herein by reference in their entirety.
Number | Date | Country | |
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Parent | 10959085 | Oct 2004 | US |
Child | 12408038 | US |