Puncture device

The invention provides a lancing apparatus for moving a lancet holder (32) retaining a lancet in a lancing direction (N1) from a standby position to a lancing position together with the lancet so as to cause the lancet to stick into an object. In the lancing apparatus the lancet is inserted into the lancet holder (32) in a retreating direction (N2), thus to be retained by the lancet holder. The lancet holder (32) includes a first member and a second member (33, 34) relatively movable with respect to each other, so that the first and the second members (33), (34) are relatively moved so as to fix the lancet. Preferably, the lancet holder (32) is constructed such that at least either of the first and the second members (33, 34) applies a pressing force to the lancet, so as to fix the lancet.

TECHNICAL FIELD

The present invention relates to a lancing apparatus used for collecting e.g. blood or a tissue via skin.

BACKGROUND ART

Some of the existing lancing apparatuses include a lancet holder that holds a lancet, which is caused to move together with the lancet holder so as to stick into a skin (see JP-A-2001-425 for example). The lancing motion of the lancing apparatus disclosed in this document can be achieved by the structure of a lancing apparatus9shown inFIGS. 32A-32C. The lancing apparatus9utilizes the spring force of a coil spring90, thereby moving a lancet92together with a lancet holder91.

In the lancing apparatus9, as shown inFIG. 32A, an engaging hook93of the lancet holder91is latched on a stepped portion95of the housing94, so that the coil spring90can store the spring force. When an operating knob96is pressed down, a working portion97of the operating knob96acts on the engaging hook93as shown inFIG. 32B, so as to release the engaging hook93. This permits the spring force of the coil spring90to act on the lancet holder91as shown inFIG. 32C, so that the lancet92is moved in a lancing direction N1together with the lancet holder91.

As is apparent fromFIG. 32C, in the lancing apparatus9the lancet92is inserted into a bore98of the lancet holder91, to be retained. The lancet92is retained by friction between the outer surface of the lancet92and the inner surface of the bore98. With such an arrangement, a relatively large frictional resistance is required between the outer surface of the lancet92and the inner surface of the bore98, in order to enable the lancet holder91to firmly retain the lancet92. Conventionally, it is difficult to check whether the lancet92has been fully inserted into the bore98of the lancet holder91, when loading the lancet92in the bore98. The structure of the lancing apparatus9allows the lancing action to be performed regardless of whether the lancet92is fully inserted into the bore98. Thus, it could happen that the lancing action may be performed, with the lancet92inserted only halfway into the bore98. In this case, the lancet92may stick too deeply into the skin. Further, the large frictional resistance between the outer surface of the lancet92and the inner surface of the bore98incurs additional drawbacks. For example, it requires a relatively large force for inserting the lancet92into the bore98, and also makes it difficult to remove the lancet92from the lancet holder91.

It could be an option to redesign both of the lancet and the lancet holder so as to allow the lancet to be securely loaded in position on the lancet holder and to be easily removed from the holder, in order to eliminate the foregoing drawbacks. Redesigning the shape of the lancet, however, reduces the compatibility of the lancet with different types of lancing apparatuses, thus spoiling the versatility of the lancet.

DISCLOSURE OF THE INVENTION

Accordingly, it is an object of the present invention to provide a lancing apparatus with which an existing lancet is properly loaded into the lancet holder without modifying the design of the lancet, and also with which the loaded lancet is easily removed.

The present invention provides a lancing apparatus comprising a lancet holder for retaining a lancet. The lancet holder is movable in a lancing direction from a standby position to a lancing position together with the lancet so as to cause the lancet to stick into an object. The lancet is inserted into the lancet holder in a retreating direction which is opposite to the lancing direction, and retained by the lancet holder. The lancet holder includes a first member and a second member that are movable relative to each other. The first and the second members are relatively moved so as to fix the lancet to the holder.

Preferably, in the lancing apparatus, at least one of the first and the second members applies a pressing force to the lancet for fixing the lancet.

In the lancing apparatus according to the present invention, when loading the lancet for example, the first member relatively moves with respect to the lancet, while the second member moves together with the lancet with respect to the first member in the retreating direction from a first position toward a second position. In this case, it is preferable that the lancet holder applies a greater pressing force to the lancet when the second member is located at the second position, than when the second member is at the first position.

In the lancing apparatus according to the present invention, it is preferable that the second member includes fixing means that applies a pressing force to the lancet so as to fix the lancet when the second member is at the second position. In this case, it is preferable that the first and the second members respectively include a first engaging portion and a second engaging portion that are engaged with each other when the second member is at the second position, and that constitute the fixing means. At least one of the first and the second engaging portions is formed so as to project toward the other of the first and the second engaging portions. Preferably, one of the first and the second engaging portions comprises a recess, while the other of the first and the second engaging portions comprises a projection to be fitted into the recess.

The first member may include a pressing portion that applies a pressing force to the lancet. In this case, it is preferable that the second member includes a working portion that displaces at least a part of the pressing portion so as to separate from the lancet when the second member is at the first position or between the first position and the second position.

The pressing portion may include a pair of movable portions, between which is defined a gap through which the working portion is caused to move. The gap is expanded when the working portion moves through the gap, so that at least a part of the movable portions is displaced so as to separate from the lancet. At least one of the movable portions may include at least one cutaway that defines a part of the gap, and that the working portion is fitted into.

The above-mentioned cutaway may comprise a first cutaway portion into which the working portion is fitted in fixing the lancet, and a second cutaway portion into which the working portion is fitted in discharging the lancet. The cutaway portion may be arranged to make the gap continuously or incrementally narrower when the working portion relatively moves with respect to the first member in the lancing direction. Specifically, the cutaway portion preferably includes at least one tapered portion that makes the gap wider continuously as proceeding in the lancing direction, and may also include at least one stepped portion that makes the gap wider sequentially as proceeding in the lancing direction.

The pressing portion may include a fixed portion and a movable portion that define a gap through which the working portion is moved. In this case, the gap is expanded when the working portion moves through the gap, so that at least a part of the movable portions is displaced so as to separate from the lancet.

The second member may include a pair of movable portions for holding the lancet therebetween. In this case, the movable portions are displaced so as to separate from the lancet when the second member is relatively moved with respect to the first member in the lancing direction, while also being displaced toward the lancet when the second member is relatively moved with respect to the first member in the retreating direction.

Use may be made of a lancet provided with a recessed portion. In this case, the movable portion may include an engaging portion to be engaged with the recessed portion of the lancet.

Preferably, the lancing apparatus according to the present invention may further comprise a pushing member that moves the second member in the lancing direction. The pushing member may include a working portion to interfere with the second member and an operating portion to be manipulated so as to move the working portion.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the accompanying drawings, a first to a fifth embodiments of the present invention will be described below.

First, description is made on the first embodiment of the present invention. A lancing apparatus X shown inFIG. 1is used for moving a lancet1from a standby position (where the lancet1is depicted in solid lines inFIG. 1) to a lancing position (where the lancet1is depicted in imaginary lines inFIG. 1) so as to stick into a skin to cause bleeding. The lancing apparatus X includes a housing2, a lancet moving mechanism3, a latch-release mechanism4and a lancet discharge mechanism5.

The lancet1, an element that sticks into the skin as noted above, is retained by a lancet holder32to be described later, so that it can be moved by the movement of the lancet holder32. The lancet1includes a main body10and a needle11projecting from the body, and may be used as a disposable item. The main body10is made of a resin or the like into a column shape. The needle11, made of a metal for example, is insert-molded in the main body10.

The housing2provides a space that accommodates various components, and includes a first and a second sleeves21,22.

The first sleeve21is formed with a protrusion21aand a first to a third openings21bto21d. The protrusion21ais engageable with a moving plate31of the lancet moving mechanism3for holding it in place. The first opening21bpermits an operating knob31B of the moving plate31to move through it. The second opening21cpermits a movement of a release button42of the latch-release mechanism4to be described. The third opening21dpermits a movement of a manipulating portion51of the lancet discharge mechanism5to be described.

The second sleeve22is open at both ends so as to allow the lancet holder32to move. The second sleeve22can be removably attached to a tip portion of the first sleeve21, a shown inFIGS. 1 and 2. Accordingly in the lancing apparatus X, the lancet1can be easily loaded on the lancet holder32when the second sleeve22is removed from the first sleeve21.

As shown inFIG. 3, the lancet moving mechanism3includes a link unit30, the moving plate31, and the lancet holder32. The lancet moving mechanism3serves to convert a reciprocating motion of the moving plate31into a reciprocating motion of the lancet holder32via a circular motion of the link unit30.

Referring toFIGS. 3 and 4, the link unit30causes the lancet holder32to move as the moving plate31moves. The link unit30includes a first movable pin30a, a second movable pin30b, a fixed pin30c, a first arm30A and a second arm30B.

The first movable pin30ais engaged with the moving plate31, and also serves to connect the first and the second arms30A,30B. Specifically, the first movable pin30ais connected with the first and the second arms30A,30B at the respective end portions30Aa,30Ba, such that the other end portions30Ab,30Bb of the first and the second arms30A,30B are offset from each other.

The second movable pin30b, which is engaged with the lancet holder32, is disposed so as to project in the opposite direction to the first movable pin30a, from the end portion30Ab of the first arm30A.

The fixed pin30cis disposed so as to project from the end portion30Bb of the second arm30B in the opposite direction to the first movable pin30a, to serve to pivotally fix the link unit30to the housing2.

In the link unit30, since the pins30ato30care mutually linked via the first and the second arms30A,30B as shown inFIG. 5, the positional relation among the pins30ato30cis fixed. Specifically, the first and the second movable pins30a,30bare equally spaced from the fixed pin30c, while the second movable pin30bis shifted by 45 degrees with respect to the first movable pin30aon a circular plane with the fixed pin30cas the center. Accordingly, rotating the link unit30around the fixed pin30ccauses the first and the second movable pins30a,30bto make a circular motion around the fixed pin30c, and the first and the second movable pins30a-30b, as viewed in a lancing direction and a retreating direction N1-N2, constitute sine waves, the phases of which are shifted by 45 degrees from each other.

The moving plate31, which is movable with respect to the housing2in the lancing direction N1and the retreating direction N2as shown inFIGS. 6A and 6B, is connected to the housing2via a coil spring Sp. The moving plate31is formed with a slot31A, an operating knob31B and a hook portion31C.

The slot31A permits the movement of the first movable pin30aof the link unit30(seeFIG. 3). The slot31A includes an inclined portion31Aa obliquely extending with respect to the lancing and the retreating directions N1, N2, and straight portions31Ab connected respectively to the end portions of the inclined portion31Aa. As shown inFIGS. 15A-15D, the first movable pin30ais caused to move in the inclined portion31Aa at least when the lancet1moves from the standby position to the lancing position, while it is caused to move in the straight portion31Ab at least when the lancet1moves away from the lancing position in the retreating direction N2.

With the slot31athus formed, the position of the moving plate31inside the housing2is determined by two positions, i.e., an absolute position of the first movable pin30aas viewed in the lancing and retreating directions N1-N2and a relative position of the first movable pin30aas viewed in the slot31A. More specifically, the position of the moving plate31is determined by the difference between a position of the first movable pin30awith respect to the fixed pin30cin the directions N1-N2and a position of the first movable pin30awith respect to the center of the slot31A in the directions N1-N2. Thus, a clockwise rotation of the link unit30causes the moving plate31to reciprocate between a free position (upper dead point) and a latch position (lower dead point), with the fixed pin30cset as the center of the operation.

As is understood fromFIGS. 6A and 6B, the operating knob31B is used to manually move the moving plate31. The operating knob31B, a portion of which protrudes out of the housing2through the first opening21b, can be moved in the lancing and retreating directions N1, N2within the first opening21b.

The hook portion31C is engaged with the protrusion21aof the housing2, so as to latch the moving plate31thereon. As is apparent fromFIG. 6B, when the coil spring Sp is shrunk the moving plate31is positioned such that the hook portion31C is located behind the protrusion21aalong the retreating direction N2. In contrast, as shown inFIG. 6A, when the hook portion31C is engaged with the protrusion21a, the moving plate31is biased in the retreating direction N2by the expanded coil spring Sp.

Referring toFIGS. 7,8A and8B, the lancet holder32serves to retain and move the lancet1(seeFIG. 1), and is movable in the lancing and retreating directions N1, N2, like the moving plate31(seeFIGS. 6A and 6B). The lancet holder32includes a first and a second members33,34that are relatively movable with respect to each other.

The first member33includes a holder35for retaining the lancet1(seeFIG. 1), a first plate36linked to the moving plate31via the link unit30(seeFIGS. 3 to 5), and a second plate37disposed so as to oppose the first plate36, as shown inFIGS. 7 to 9.

The holder35includes a lancet chamber38in which the lancet1(seeFIG. 1) is loaded, and a confining portion39that inhibits a radial movement of the lancet1(FIG. 1). The lancet chamber38is of a semicylindrical shape having an inner surface that fits on the outer surface of the lancet1, and includes a pair of guide portions38A and a wall portion38B. As seen inFIGS. 8A and 8B, the guide portion38A serves to guide a movement of an arch portion34of the second member34which will be described later. The wall portion38B is formed with a cutaway portion38b. The cutaway portion38bis formed in a semicircular shape at and end portion of the lancet chamber38as shown inFIG. 9, so as to serve to guide a movement of a pin34bof the second member34. The confining portion39is integrally formed with the holder35, so as to have an inner diameter that fits on the outer diameter of the lancet1(FIG. 1).

The first plate36is elongated in the lancing and retreating directions N1, N2, and formed with a slot36aat an end portion. The slot36aprovides, as seen fromFIGS. 1 and 3, room for allowing the second movable pin30bof the link unit30to move, and is orthogonally elongated with respect to the lancing and retreating directions N1, N2. Accordingly, as shown inFIGS. 15A to 15D, the position of the first plate36(lancet holder32) corresponds to the position of the second movable pin30bin the lancing and retreating directions N1, N2. Consequently, a rotation of the link unit30causes the lancet holder32to perform a reciprocating movement with the fixed pin30cas the center of the stroke.

Referring toFIGS. 8A,8B and9, the second plate37serves to guide the movement of a pushing member50(seeFIGS. 14A and 14B) of the lancet discharge mechanism5, in cooperation with the first plate36. The second plate37is connected to the first plate36via a bridge portion37A. The bridge portion37A includes a recess37Aa to be engaged with a protrusion34C of the second member34.

The second member34is moved in the lancing or retreating direction N1or N2, when loading the lancet1(seeFIG. 1), by an action of the lancet discharge mechanism5, as shown inFIGS. 8A and 8B. The second member34includes an arch portion34A and a stopper34B.

Referring toFIG. 10, the arch portion34A is semicylindrical so as to cover the outer surface of the lancet1(seeFIG. 1), and is bridged over the guide portion38A of the first member33, as shown inFIGS. 7,8A and8B.

Referring toFIGS. 8A and 8B, the stopper34B is butted to the wall portion38B of the first member33when the second member34relatively moves with respect to the first member33in the lancing direction N1, thus to limit the relative movement of the second member34with respect to the first member33in the lancing direction N1. The stopper34B includes a pin34bprojecting in the lancing direction N1. The pin34bis butted to the lancet1(seeFIG. 1) when loading the lancet1in the lancet holder32, and is moved through the cutaway portion38bin the wall portion38B of the first member33.

The second member34includes a semispherical protrusion34C located close to the stopper34B. The protrusion34C, which is fitted to the recess37Aa in the bridge portion37A of the first member33, is slightly larger in dimension than the recess37Aa. The protrusion34C is located so as to be fitted to the recess37Aa when the lancet1is inserted so deeply as to be butted to the wall portion38B of the first member33. In this state, since the protrusion34C is slightly larger in dimensions than the recess37Aa, the arch portion34A is caused to apply a pressing force to the lancet1. Accordingly, when the protrusion34C is fitted to the recess37Aa, the arch portion34A and the lancet chamber38hold the lancet1(seeFIG. 1) therebetween, with the pressing force being applied to the lancet1. This allows the lancet holder32to retain the lancet1(seeFIG. 1) securely. In contrast, when the protrusion34C is disengaged with the recess37Aa, the arch portion34A only applies a smaller pressing force to the lancet1(seeFIG. 1), thereby making it easier to remove the lancet1from the lancet holder32.

As shown inFIGS. 6A and 6B, the latch-release mechanism4, which serves to unlatch the moving plate31from the housing2, includes a swinging member40. The swinging member40includes, as shown inFIG. 11, a pair of spring portions41, a release button42and a working portion43.

The pair of spring portions41has an appropriate elasticity and is extending from the working portion43. As is seen fromFIGS. 11 and 12, the pair of spring portions41are spaced from each other so as to allow the hook portion31C (seeFIGS. 6A and 6B) of the moving plate31to move through between the spring portions41. The spring portions41respectively include a fixing portion41A. The fixing portion41A serves to fix the swinging member40to the housing2. The fixing portion41A includes a pair of rib portions41a, between which an engaging piece21eprovided on the first sleeve21of the housing2is engaged.

The release button42is provided for a user to press down, and the pressing of the release button42unlatches the hook portion31C of the moving plate31, as shown inFIGS. 13A to 13C. The release button42is exposed via the second opening21cof the housing2, and movable within the second opening21c. The release button42can swing together with the working portion43with the fixing portion41A set as a fulcrum, since the swinging member40is fixed to the housing2via the fixing portion41A (seeFIG. 12), and the spring portions41have an appropriate elasticity.

The working portion43serves to apply a pressing force to the hook portion31C when the release button42is pressed down. When such a pressing force is applied, the hook portion31C is displaced toward an inner region of the housing2, thus to be disengaged as shown inFIGS. 13B and 13C. As stated above, when the hook portion31C is latched on the protrusion21a, the moving plate31is biased in the retreating direction N2. Accordingly, the unlatching of the hook portion31C causes the moving plate31to move in the retreating direction N2, as shown inFIG. 6B.

Referring toFIGS. 14A and 14B, the lancet discharge mechanism5serves to remove the lancet1from the lancet holder32after the lancing action. The lancet discharge mechanism5includes a pushing member50relatively movable with respect to the housing2and the lancet holder32in the lancing and retreating directions N1, N2. The pushing member50includes an operating portion51and a working portion52. The operating portion51is manually utilized by a user for moving the pushing member50, and movable in the lancing and retreating directions N1, N2within the third opening21d. The working portion52is butted to the stopper34B of the second member34in the lancet holder32. The working portion52is moved in the lancing direction N1between the first and the second plates36,37when the operating portion51is moved in the lancing direction N1. Accordingly, in the lancet discharge mechanism5, moving the operating portion51in the lancing direction N1causes the working portion52to move in the lancing direction N1, to move the second member34of the lancet holder32. The movement of the second member34thus caused makes the pin34bof the second member34move in the lancing direction N1, to cause the lancet1to move in the lancing direction N1.

The usage of the lancing apparatus X and its principle of operation will now be described. It should be noted here thatFIG. 15Ashows an “initial state” in which: the moving plate31is located at a free position (upper dead point) in the retreating direction N2; the first movable pin30ais at the left end portion of the inclined portion31Aa in the slot31A of the moving plate31; and the second movable pin30bis at the left end portion of the slot36aof the lancet holder32.

When lancing a skin with the lancing apparatus X, firstly the hook portion31C of the moving plate31is engaged with the protrusion21aof the housing2(“latch state”), and then the lancet1is loaded in the lancet holder32, as shown inFIGS. 1 and 15C. Alternatively, the lancet1may be loaded in the lancet holder32before the moving plate31is latched on the housing2.

The latch state can be achieved by moving the operating knob31B of the moving plate31in the lancing direction N1, as shown inFIGS. 15A to 15C.

When the moving plate31is moved in the lancing direction N1in the state shown inFIG. 15A, the link unit30as a whole, including the second movable pin30b, rotates clockwise around the fixed pin30cas shown inFIGS. 15A and 15B, so that the lancet holder32is lifted in the retreating direction N2. When the moving plate31is moved farther in the lancing direction N1in the state shown inFIG. 15B, the link unit30rotates clockwise further, thereby lowering the lancet holder32in the lancing direction N1, as shown inFIG. 15C. This causes the coil spring Sp to expand, and hence the moving plate31is biased in the retreating direction N2. In this state, the hook portion31C of the moving plate31comes into engagement with the protrusion21aof the housing2.

In first loading the lancet1, on the other hand, the second sleeve22is removed from the first sleeve21, so as to expose the confining portion39of the lancet holder32as shown inFIG. 2. Then the end portion of the lancet1opposite to the needle is inserted through the confining portion39. When the lancet1is fully inserted, the end face of the lancet1is butted to the pin34of the second member34, so that the second member34moves in the retreating direction N2together with the pushing member50of the lancet discharge mechanism5, as shown inFIG. 14B. Once the second member34has moved over a predetermined distance, the end face of the lancet1is butted to the wall portion38B of the first member33, so that the lancet1is inhibited from moving further in the retreating direction N2. At this point, the protrusion34C of the second member34fits with the recess37Aa of the first member33. This causes the second member34to be pressed against the first member33, to allow the first and the second members33,34to firmly hold the lancet1therebetween, thus assuring the secure retention of the lancet1by the lancet holder32. In addition, the click feeling sensed upon fitting the protrusion34C with the recess37Aa clearly notifies the user that the lancet1has been duly loaded in position. Such a structure prevents the lancet1from being insufficiently inserted and hence from sticking too deeply into the skin, which makes the lancing operation much safer.

After the moving plate31has been latched and the lancet1has been loaded, the release button42of the latch-release mechanism4is pressed to cause the lancet1to stick into the skin, as shown inFIGS. 6A,6B and13A to13C. When the release button42is pressed down, the swinging member40, including the release button42and the working portion43, is moved toward an inner region of the housing2with the fixing portion41A set as a fulcrum. By such action, the working portion43is butted to the hook portion31C thus to inwardly displace the hook portion31C, whereby the hook portion31C is unlatched from the protrusion21a, as shown inFIG. 13B.

Since the moving plate31is biased in the retreating direction N2in the latch state as stated above, the moving plate31moves in the retreating direction N2when the latch is released, which causes the link unit30to rotate clockwise, and thus the lancet holder32is pressed down in the lancing direction N1as shown inFIGS. 15C and 15D. Thereafter the moving plate31moves farther in the retreating direction N2, which causes the lancet holder32to be lifted in the retreating direction N2, and to return to the free position where the lancet holder32was before being latched on the housing2, as shown inFIG. 15A. Such action causes the lancet1to be drawn out of the skin.

When the lancing action has been completed, the lancet1is removed from the lancet holder32. To remove the lancet1, the lancet discharge mechanism5is utilized as shown inFIGS. 14A and 14B. Specifically, the operating portion51of the lancet discharge mechanism5is moved in the lancing direction N1to cause the lancet1to be removed from the lancet holder32.

When the operating portion51is moved in the lancing direction N1, the working portion52also moves in the lancing direction N1, to be butted to the stopper34B. Moving further the operating portion51in the lancing direction N1applies a force to the stopper34B in the lancing direction N1, via the working portion52. When a force of appropriate strength is applied to the stopper34B, the protrusion34C of the second member34is disengaged from the recess37Aa of the first member33, so that the second member34is moved in the lancing direction N1. Accordingly, the pin34bof the second member34presses the end face of the lancet1, so as to move the lancet1in the lancing direction N1. Since the protrusion34C is disengaged from the recess37Aa at this stage, the arch portion34A of the second member34only applies a small force to the lancet1, thus allowing the lancet1to be easily removed from the lancet holder32, without applying a great force to the lancet1.

In the lancet holder32of the foregoing lancing apparatus X, the arch portion34A of the second member34relatively moves with respect to the guide portion38A of the first member33in close contact therewith, however the lancet can be retained in the lancet holder only if a pressing force is applied to the lancet, for which purpose the arch portion34A′,34A″ of the second member34′,34″ may relatively move with respect to the guide portion38A′,38A″ of the first member33′,33″ with an appropriate spacing, so that the arch portion34A′,34A″ of the second member34′,34″ is inwardly displaced to be pressed against the lancet1, as shown inFIGS. 16A and 16Bor inFIGS. 16C and 16D.

Specifically, in the lancet holder32′ shown inFIGS. 16A and 16B, the protrusion34C′ of the second member34′ is fitted to the recess37Aa′ of the first member33′, so as to inwardly displace the arch portion34A′.

In contrast, in the lancet holder32″ shown inFIGS. 16C and 16D, another protrusion34D″ is provided on the second member34″ in addition to the protrusion34C″ to be fitted to the recess37Aa″ of the first member33″, and also another protrusion37B″ is provided on the first member33″, so as to be fitted to the protrusion34D″. The protrusion37B″ is inwardly protruding, with its top located at an inner position than the top of the protrusion34D″ of the second member34″. Accordingly, when the second member34″ is relatively moved so as to make access to the first member33″ until the protrusion34D″ of the second member34″ interferes with the protrusion37B″ of the first member33″, the arch portion34A″ of the second member34″ is inwardly displaced.

According to the present invention, for engaging the second member of the lancet holder with the first member to cause the second member to apply a pressing force to the lancet, the structure shown inFIGS. 17A to 17C, or inFIGS. 18A and 18Bmay be employed.

FIG. 17Ashows a structure in which the first member33of the lancet holder32is provided with a semispherical protrusion37A, while the second member34is formed with a recess34Ca into which the protrusion37Ab is fitted. InFIG. 17B, the first member33of the lancet holder32includes a semispherical protrusion37Ab, and the second member34is fixed into the first member33and held by the resistance between the protrusion37Ab and the second member34. InFIG. 17C, a semispherical protrusion34C is provided on the second member34of the lancet holder32, and the second member34is fixed into the first member33and held by the resistance between the protrusion34C and the first member33.

InFIG. 18A, the first member33of the lancet holder32includes a tapered protrusion37Ac, so that the second member34is fixed into the first member33and held by the resistance between the protrusion37Ac and the second member34. InFIG. 18B, the second member34of the lancet holder32includes a tapered protrusion34Cb, so that the second member34is fixed into the first member33and held by the resistance between the protrusion34Cb and the first member33.

Now, a second embodiment of the present invention will be described.

FIGS. 19A and 19Bshows a lancet holder6, in which a second member60includes a first and a second flexible portions61,62. The first flexible portion61includes a protrusion61ato be fitted into a recess64aprovided on a bridge portion64of a first member63. The first member63A includes through-holes65a,65blocated on a wall portion65, so as to permit a movement of a working portion66of the second member60and the second flexible portion62.

As shown inFIG. 19A, the first and the second flexible portions61,62do not touch the lancet1when the second member60is on the side indicated by the arrow N1, and hence do not apply a pressing force to the lancet1. In contrast, when the second member60is moved in a direction indicated by the arrow N2from the state ofFIG. 19Ato the state shown inFIG. 19B, the first flexible portion61interferes with the bridge portion64thus to be displaced in a direction of accessing the lancet1, and the second flexible portion62interferes with an inner wall of the through-hole65bthus to be displaced in a direction of accessing the lancet1. Consequently, the first and the second flexible portions61,62are brought into contact with the lancet1, thereby applying a pressing force to the lancet1.

Now, a third embodiment of the present invention will be described.

A lancet holder according to this embodiment can be suitably employed for a lancet1′ shown inFIG. 20A. The lancet1′ is also a general-purpose product like the foregoing lancet1(seeFIG. 2) having a column-shaped main body10, and includes a recessed portion12′ on a main body10′. The lancet1′ includes a stepped portion13′ defined by the recessed portion12′.

As shown inFIGS. 20B and 20C, a lancet holder7is basically similar to the lancet holder6(seeFIGS. 19A and 19B) according to the third embodiment. A difference in the lancet holder7from the lancet holder6(seeFIGS. 19Aand19B) lies in that a first and a second flexible portions71,72respectively include a protrusion71b,72bat en end portion. The protrusions71b,72bserve to get engaged with the stepped portion13′ of the lancet1′, as explicitly shown inFIG. 20C.

The lancet holder7is unable to apply a pressing force to the lancet1′ when the first and the second flexible portions71,72of a second member70are located on the side indicated by the arrow N1. However, when the second member60is moved in a direction indicated by the arrow N2under the state ofFIG. 20Bthus to present a state as shown inFIG. 20C, the first and the second flexible portions71,72are brought into contact with the lancet1′, thereby applying a pressing force to the lancet1′. In this state, the protrusions71b,72bof the first and the second flexible portions71,72are respectively engaged with the stepped portion13′ of the lancet1′. Such a structure ensures the secure retention of the lancet1′, by the first and the second flexible portion71,72.

While this embodiment represents a case where the general-purpose lancet including the recessed portion12′ is employed, a lancet including a customized recessed portion that fits the protrusions71b,72bof the first and the second flexible portions71,72may be produced, for use with the lancet holder7.

Now, a fourth embodiment of the present invention will be described. This embodiment relates to a modification of the lancet holder.

Referring toFIG. 21, a lancet holder8includes a first and a second members80,81relatively movable with respect to each other.

As shown inFIGS. 22 and 23, the first member80includes a holder body82, a confining portion83and a guide portion84.

The holder body82has an inner surface that fits on the outer surface of the lancet1, with an inner diameter equal to or slightly smaller than the outer diameter of the lancet in a natural condition of the holder body82. The holder body82includes a lancet chamber85, a pair of movable portions86and a stopper87.

The lancet chamber85is of a semicylindrical shape. The pair of movable portions86, which are formed as an extension of the holder body82to cover an inner portion of the lancet chamber85, serve to apply a pressing force to the lancet1. The movable portions86have an arc-shaped inner surface, such that the respective end faces86A oppose each other across a gap86B. The gap86B has a uniform width along its main portion86Ba, while includes arc-shaped cutaway portions86Bb at the respective corners of the movable portions86, thus having a larger width at an end portion thereof. The pair of movable portions86can be outwardly displaced by expanding the gap86B. The stopper87can interfere with the end face of the lancet1when loading the lancet, thus to inhibit further movement of the lancet1. The stopper87includes a cutaway portion87a. The cutaway portion87aserves to guide a movement of a column-shaped portion89bof the second member81to be described later.

The confining portion83inhibits a radial movement of the lancet1. The confining portion83constitutes an extension of the holder body82in a ring shape, with an inner diameter slightly larger than the outer diameter of the lancet1(inner diameter of the holder body82).

As seen fromFIGS. 21 and 22, the guide portion84serves to guide a movement of the second member81, and includes a sliding portion88a. Two block portions88bextend from the sliding portion88a, and a gap88cis provided between the sliding portion88aand the respective block portions88b.

As shown inFIGS. 21 and 24, the second member81is to be moved in the lancing or retreating direction N1or N2, along the sliding portion88aof the first member80. The second member81is made of a plate89awith a column-shaped portion89blocated at an end portion, and with a flange portion89cextending from a plate-shape portion.

The column-shaped portion89bserves to interfere with the lancet1and to expand the width of the gap86B of the first member80, as seen inFIGS. 25A,25B,26A and26B. The column-shaped portion89bhas a larger diameter than the width of the main portion86Ba of the gap86B, and an outer surface that fits on the inner surface of the cutaway portions86Bb of the first member80. The flange portion89cis to be guided by the block portions88bof the first member80, so as to move through the gap88con the first member80.

When loading the lancet1in the lancet holder8, an end portion of the lancet1opposite to the needle11(seeFIG. 23) is inserted through the confining portion83. In the lancet holder8at this stage, as shown inFIGS. 25A and 26A, the gap86B of the first member80is expanded since the column-shaped portion89bof the second member81is located in the main portion86Ba of the gap86B. When the lancet1is inserted by a predetermined depth, the end face of the lancet1is butted to the column-shaped portion89b, so as to move the column-shaped portion89bin the retreating direction N2through the main portion86Ba of the gap86B. When the lancet1has moved over a predetermined distance, the end face of the lancet1is butted to the stopper87of the first member80, which inhibits further movement of the lancet1in the retreating direction N2, as shown inFIGS. 25B and 26B. At this stage, the column-shaped portion89bfalls in the cutaway portions86Bb of the first member80. This causes the movable portions86to be inwardly displaced thus to reduce the width of the gap86B, so that the movable portions86of the first member80apply a pressing force to the lancet1. In addition, when the column-shaped portion89bfits into the cutaway portions86Bb, the user feels a click, to be assured that the lancet1has been properly loaded in the lancet holder8.

In contrast, the removal of the lancet1from the lancet holder8is performed by moving the second member81in the lancing direction N1. The second member81may be moved via the lancet discharge mechanism5according to the first embodiment.

Specifically, by moving the column-shaped portion89bin the lancing direction N1when the column-shaped portion89bis fitted in the cutaway portions86Bb, the column-shaped portion89bis disengaged and caused to move through the main portion86Ba of the gap86B. This expands the main portion86Ba of the gap86B by outwardly displacing the movable portions86, thereby reducing the pressing force so far applied to the lancet1by the movable portions86. This ensures easy removal of the lancet1from the lancet holder8.

The structures of the gap86of the first member80and the column-shaped portion89bof the second member81are not limited to those described in the foregoing embodiment. For example, the gap86B has only to include a portion narrower than the diameter of the column-shaped portion89b, and does not necessarily have to include a cutaway portion.

A fifth embodiment of the present invention will now be described. This embodiment also relates to a modification of the lancet holder.

As shown inFIG. 27, a lancet holder8C is of a similar shape to the lancet holder8according to the fourth embodiment (seeFIGS. 21,22), and includes a first and a second members80C,81C relatively movable with respect to each other. In the first member80C, movable portions86C respectively include two arc-shaped cutaway portions86Ca,86Cb, so that a gap86CA defined therebetween has a larger width at both end portions. However, the first member80C does not include the confining portion83(seeFIGS. 21,22and so on) included in the foregoing lancet holder8. The second member81C is of generally the same structure as the second member81of the lancet holder8.

The cutaway portions86Ca of the movable portions86C have a similar function to that of the cutaway portions86Bb (seeFIGS. 21,22) of the lancet holder8. More specifically, the cutaway portions86Ca are to be engaged with the column-shaped portion89Cb of the second member81C, to provide a click feeling when the lancet1(seeFIGS. 28A to 28C) is fixed in place in the lancet holder8C. The cutaway portions86Cb are to be engaged with the column-shaped portion89Cb when the lancet1is discharged from the lancet holder8. Accordingly, the user recognizes that the lancet1(seeFIGS. 28A to 28C) has been discharged upon feeling the click when the column-shaped portion89Cb fits into the cutaway portions86Cb.

As shown inFIGS. 28A to 28C, when loading the lancet1in the lancet holder8C, the end portion of the lancet1opposite to the needle11is inserted, with the column-shaped portion89Cb of the second member81C engaged with the cutaway portions86Cb of the first member80C. At this moment in the lancet holder8C, as shown inFIGS. 28A and 28B, the lancet1is butted to the column-shaped portion89Cb so as to move the column-shaped portion89Cb in the retreating direction N2through a main portion86CA′ of a gap86CA. This expands the width of the gap86CA from the natural state. When the lancet1has moved over a predetermined distance, the end face of the lancet1is butted to the stopper87C of the first member80C, so that the lancet1is inhibited from moving further in the retreating direction N2, as shown inFIGS. 28B and 28C. At this point, the column-shaped portion89Cb falls in the cutaway portions86Ca of the first member80C. This causes the movable portions86C to be inwardly displaced thus to reduce the width of the gap86CA, so that the movable portions86C of the first member80C apply a pressing force to the lancet1. In addition, when the column-shaped portion89Cb fits into the cutaway portions86Ca, the user feels a click, to know that the lancet1has been properly loaded in the lancet holder8C.

In contrast, the removal of the lancet1from the lancet holder8C is performed by moving the second member81C in the lancing direction N1. The second member81C may be moved via the lancet discharge mechanism5(seeFIGS. 14A and 14B) according to the first embodiment.

As seen fromFIGS. 28B and 28C, moving the column-shaped portion89Cb in the lancing direction N1when the column-shaped portion89Cb is fitted in the cutaway portions86Bb causes the column-shaped portion89bto be disengaged and to move through the main portion86CA′ of the gap86CA. This expands the main portion86CA′ of the gap86CA by outwardly displacing the movable portions86C, thereby reducing the pressing force so far applied to the lancet1by the movable portions86C. This ensures easy removal of the lancet1from the lancet holder8. As seen fromFIGS. 28A and 28B, moving the column-shaped portion89Cb farther in the lancing direction N1causes the lancet1to be discharged from the lancet holder8C, since the movable portions86C is barely applying a pressing force to the lancet1. At this point, the column-shaped portion89Cb falls in the cutaway portions86Cb. Accordingly, the user recognizes that the lancet1has been discharged from the lancet holder8C upon feeling a click when the column-shaped portion89Cb fits into the cutaway portions86Cb.

The foregoing structure of the cutaway portions86Cb of the movable portion86C may be modified in various manners, as shown inFIGS. 29A to 29F. Cutaway portions86Db to86Ib shown therein are shaped such that gaps86DA to86IA become wider at a position farther ahead in the lancing direction N1.

Specifically, the cutaway portion86Db shown inFIG. 29Aincludes a stepped portion86Dc, so that the width of the gap86DA becomes wider sequentially at the stepped portion86Dc. The cutaway portion86Eb shown inFIG. 29Bincludes a plurality of stepped portions86Ec in a stair shape, so that the gap86EA becomes wider over a number of stages at the stepped portion86Ec. The cutaway portions86Fb to86Ib shown inFIGS. 29C to 29Frespectively include tapered portions86Fc to86Ic, so that the tapered portions86Fc to86Ic continuously expand the width of the gaps86FA to86IA.

In the case where the movable portions86D to86I include the cutaway portions86Db to86Ib, the movable portions86D to86I return to the natural state once the column-shaped portions89Db to89Ib fit in the cutaway portions86Db to86Ib, thereby applying a returning spring force to the column-shaped portion89Db to89Ib. When this spring force of the movable portions86D to86I acts on the column-shaped portions89Db to89Ib, the force may drive the column-shaped portion89Db to89Ib, and hence the second member81D to81I to abruptly move in the lancing direction N1, thus causing the lancet1(seeFIG. 2) to jump out of the lancet holder8D to8I.

In the lancet holder8D to8I, however, because of the shapes of the foregoing cutaway portions86Db to86Ib, the width of the gap86DA to86IA is continuously or incrementally reduced when the column-shaped portion89Db to89Ib moves in the lancing direction N1. Accordingly, the movable portions86D to86I gradually return to the natural state, rather than abruptly. This prevents the column-shaped portion89Db to89Ib from being abruptly subjected to a large force. Therefore, the lancet holder8D to8I can prevent the lancet1(seeFIG. 2) from jumping out, when discharging the lancet1.

Here, in order to assure the foregoing advantage with respect to the cutaway portions86Fb to86Ib including the tapered portions86Fc to86Ic, it is preferable to form the tapered portions86Fc to86Ic in a gentle slope with respect to the lancing direction N1, specifically in a range of 10 to 45 degrees, for example.

The movable portions86,86C to86I according to the fourth and the fifth embodiments of the present invention do not necessarily have to constitute a pair. For example as shown inFIG. 30, a lancet holder8J may be designed such that a holder body82J includes a fixed portion86Ja and a movable portion86Jb located so as to oppose the fixed portion86Ja across a gap86JB. With such structure, moving the column-shaped portion89Jb of the second member81J through a main portion86Jba of the gap86JB can displace the movable portion86Jb with respect to the fixed portion86Ja. This results in a decrease in the pressing force so far applied to the lancet1by the movable portion86Jb, thus allowing easy removal of the lancet1from the lancet holder8J.

In a lancet holder8K shown inFIGS. 31A and 31B, a second member81K includes a tapered portion81KA at an end portion, so as to outwardly displace a movable portion86K. With such structure, since the movable portion86K touches different regions of the tapered portion81KA when the second member81K is moved, the movable portion86K can be thus displaced.

The present invention may be modified in various manners without limitation to the foregoing embodiments. To cite a few examples, while the lancing apparatus X is constituted such that a spring force of the coil spring Sp is applied to the moving plate31so as to move the lancet holder32, an elastic material other than the coil spring Sp may be employed to apply a spring force to the moving plate31, or the moving plate may be moved by a driving force such as a pneumatic power or an electromagnetic power. Further, the moving plate may be omitted so that the driving force is directly applied to the lancet holder, to thus move the lancet holder.

While the second member of the lancet holder is provided as an independent component from other constituents including the pushing member50(seeFIGS. 14A and 14B) of the lancet discharge mechanism5in the foregoing embodiments, a constituent that serves as both the second member and the pushing member may be provided as a unified member.