CN112043290B

CN112043290B - Negative pressure blood sampling pen

Info

Publication number: CN112043290B
Application number: CN202011074868.8A
Authority: CN
Inventors: 胡超宇
Original assignee: Puang Hangzhou Medical Technology Co ltd
Current assignee: Puang Hangzhou Medical Technology Co ltd
Priority date: 2020-10-09
Filing date: 2020-10-09
Publication date: 2021-05-11
Anticipated expiration: 2040-10-09
Also published as: CN112043290A

Abstract

The invention relates to the technical field of medical treatment, in particular to a negative pressure blood sampling pen, which at least comprises a negative pressure forming process in a pressure change cavity, wherein the negative pressure forming process comprises a first stage, a second stage and a third stage, the first stage of forming negative pressure in the pressure change cavity is isolated from the outside, the adsorption effect of a negative pressure environment in the pressure change cavity on peripheral skin is stable and reliable, a bulge extending to the pressure change cavity is formed at the peripheral skin, a blood sampling needle punctures on the bulge, and the pain of a patient is lower; after the blood taking needle punctures, although the pressure variation intracavity has the outside air to get into in second stage, third stage, still can keep negative pressure environment in certain time, make the interior blood of tip swell collect to puncture department, so, can gather required blood sampling volume under the less shallow condition of puncture for patient's pain is felt less, experiences better.

Description

Negative pressure blood sampling pen

Technical Field

The invention relates to the technical field of medical treatment, in particular to a negative pressure blood sampling pen.

Background

A blood taking pen for taking peripheral blood is a common medical instrument and is matched with a disposable blood taking needle for use. In the prior art, the conventional blood sampling pen has unstable control of pain, puncture depth, bleeding amount and the like in the using process.

Therefore, a blood sampling pen with a negative pressure function is provided in the market, namely, a negative pressure cavity is formed in the blood sampling pen when a blood sampling needle is triggered, a tip skin is absorbed into the negative pressure cavity through negative pressure to form a bulge, and the blood sampling needle punctures on the bulge to form a blood sampling point. The advantage of negative pressure blood sampling pen lies in, can reduce patient's pain during the puncture and feel, simultaneously because the absorption of negative pressure environment to skin, blood can be to the gathering of swell department, and the amount of bleeding can be bigger, so can obtain required blood sampling volume through less puncture degree of depth.

For example, the chinese utility model patent with publication number CN211066647U discloses a negative pressure painless blood sampling pen, which has the function of negative pressure blood sampling. In the above patent, the vent hole 100 penetrates through the key 17 and the trigger 18, and after triggering, in the process of negative pressure formed in the inner cavity, since the vent hole is communicated with the outside, the outside air can enter the negative pressure cavity, so that the formed negative pressure environment has limited suction force, the negative pressure adsorption effect on the skin is general, and the effect is poor.

Disclosure of Invention

The invention aims to solve the technical problem of poor blood sampling effect caused by a blood sampling method of a negative pressure blood sampling pen in the prior art.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: the utility model provides a negative pressure blood sampling pen, includes striking blood sampling device, the body of rod and actuating mechanism at least, striking blood sampling device includes at least:

-a base;

a front cover, the front end of which is provided with a puncture hole, the rear end of which is detachably connected with the base, the front cover and the base forming a first space;

-a needle hub located within the first space;

-a strike block comprising at least a first state of abutment with the tail end of the needle hub and a second state of separation from the tail end of the needle hub, the strike block being connected to the needle hub by the second elastic member;

the rod body is connected with one end of the base far away from the front cover, and the side wall of the rod body is provided with a vent hole;

actuating mechanism includes the piston at least and sets up in the absorption piece of piston tip, the striking piece be configured into can with absorption piece magnetism is inhaled the formula and is connected, the piston is located in the body of rod and with body of rod axial swing joint, the space between piston front end and the puncture forms the pressure change chamber, the negative pressure formation process in the pressure change chamber includes at least:

the method comprises the following steps that in the first stage, the volume of a pressure change cavity is rapidly increased and is isolated from the outside, before the first stage begins, the pressure in the pressure change cavity is equal to the outside air pressure, along with the change of the volume of the pressure change cavity, first negative pressure is formed in the pressure change cavity, and the first negative pressure is continuously increased along with the change of the volume of the pressure change cavity;

a second stage in which the pressure change chamber is communicated with the outside through a vent hole; and

and in the third stage, the volume of the pressure change cavity is continuously increased, and in the volume increasing process of the pressure change cavity, the outside air continuously enters the pressure change cavity from the vent hole and forms second negative pressure.

In a preferred embodiment, after the volume of the pressure change chamber is increased to a limit position, the external air continues to enter the pressure change chamber under the action of the pressure difference until the pressure in the pressure change chamber is equal to the external pressure.

In a preferred embodiment, in the second stage, the volume of the pressure change chamber is equal to 0.2-0.8 times the maximum volume of the pressure change chamber.

In a preferred embodiment, before the first stage starts, the lancet in the negative pressure lancet is in a state of waiting to be triggered, and a time node at which the lancet is triggered from the state of waiting to be triggered is after the first stage starts.

In a preferred embodiment, the lancet further comprises a puncture state in which the negative pressure forming process in the pressure change chamber is located in a second half of the first stage to a first half of the third stage.

In a preferred embodiment, the lancet returns to the initial state after the puncture is performed.

In the negative pressure blood sampling pen of the embodiment, in the first stage of forming negative pressure in the pressure change cavity, the pressure change cavity is isolated from the outside, the adsorption effect of the negative pressure environment in the pressure change cavity on the peripheral skin is stable and reliable, so that a bulge extending into the pressure change cavity is formed at the peripheral skin, and the blood sampling needle punctures on the bulge, so that the pain of a patient is lower; after the blood taking needle punctures, although the pressure variation intracavity has the outside air to get into in second stage, third stage, still can keep negative pressure environment in certain time, make the interior blood of tip swell collect to puncture department, so, can gather required blood sampling volume under the less shallow condition of puncture for patient's pain is felt less, experiences better.

Drawings

FIG. 1 is a schematic external view of a blood collection pen according to the present embodiment;

FIG. 2a is a schematic diagram of the first embodiment of the impact lancing device in an exploded configuration;

FIG. 2b is a schematic diagram of an exploded state of an impact type blood sampling device according to a second embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a base in the present embodiment;

FIG. 4a is a schematic structural view of an inner front cover of the first embodiment in this embodiment;

FIG. 4b is a schematic structural diagram of an inner front cover of the second embodiment in this embodiment;

FIG. 5 is a schematic partial sectional front view of the outer front cover in this embodiment;

FIG. 6 is a schematic view of a partially cut-away perspective structure of the outer front cover in this embodiment;

FIG. 7 is a front view schematically illustrating the structure of the needle holder in the present embodiment;

fig. 8 is a schematic perspective view of the needle holder in the present embodiment;

FIG. 9 is a schematic perspective view of the needle hub according to another embodiment of the present invention;

FIG. 10 is a schematic structural view of an impact block in the present embodiment;

FIG. 11 is a structural diagram of the rod and the driving mechanism in an exploded state in the present embodiment;

FIG. 12 is a schematic view of a first rod of the present embodiment;

FIG. 13 is a sectional view of the second rod of the present embodiment;

FIG. 14 is a schematic structural view of a piston according to the present embodiment;

FIG. 15 is a schematic structural diagram of a junction block in the present embodiment;

fig. 16 is a schematic structural view of the drive lever in the present embodiment;

fig. 17 is a schematic connection diagram of the second rod, the adapter block and the driving rod in the initial state according to the embodiment;

FIG. 18 is a schematic connection diagram illustrating the second rod, the connecting block and the driving rod in the armed ready-to-trigger state according to the present embodiment;

FIG. 19 is a sectional view schematically showing the structure of the lancet in the initial state in the present embodiment;

FIG. 20 is a schematic structural view of the impact type blood collecting device in the initial state in the present embodiment;

FIG. 21 is a schematic sectional view of the lancet in the armed ready to trigger state in the present embodiment;

fig. 22 is a schematic structural view of the impact type blood collecting device of the present embodiment in a puncturing state.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as being fixedly connected, integrally connected, or detachably connected; may be communication within two elements; they may be directly connected or indirectly connected through an intermediate, and those skilled in the art will understand the specific meaning of the above terms in the present invention in specific situations.

The blood collection method of the negative pressure blood collection pen of the present application will be described in detail with reference to specific embodiments.

A negative pressure blood sampling pen of the present embodiment is shown in fig. 1, and includes an impact type blood sampling device 10, a rod 20, and a driving mechanism 30.

The impact-type blood sampling device 10 of the present embodiment is structured as shown in fig. 2a and 2b, and includes a base 11 and a front cover formed by nesting an outer front cover 13 and an inner front cover 12, wherein the front cover and the base 11 are detachably connected.

In this embodiment, the front cover and the interior of the base 11 form a first space, in which the needle hub 14 is mounted. The needle holder 14 is located in the first space, as shown in fig. 7 to 9, wherein the needle holder 14 includes a lancet mounting portion 141 and a needle holder body 144, and a lancet mounting groove 142 for mounting the disposable lancet 18 is provided at a front end of the lancet mounting portion 141. Preferably, the lancet mounting portion 141 is provided with a deforming groove 143 extending in the longitudinal direction and the circumferential direction, and the deforming groove 143 is provided to facilitate attachment and detachment of the lancet 18.

As shown in fig. 7-9, the outer wall of the hub body 144 of this embodiment is provided with a plurality of first guiding grooves 149 distributed along the circumferential direction, the lower end of the hub body 144 is provided with a hub flange 148, and the end surface of the lower end of the hub body 144 is further provided with a striking cavity 147 for accommodating the striking block 15.

As shown in fig. 10, the striking block 15 of this embodiment includes a striking block body 151, a first receiving groove 152 for receiving the elastic ring 16 is disposed on one side of the striking block body 151 away from the needle holder 14, and second receiving grooves 153 communicating with the first receiving groove 152 are disposed on both sides of the striking block.

Preferably, in this embodiment, the striking block 15 is connected to the needle holder 14 by an elastic ring 16. The elastic ring 16 is the second elastic member of this embodiment, and when the elastic ring 16 is in a natural state, the elastic ring has an effect of driving the striking block 15 to be attached to the tail end of the needle seat, i.e. the striking cavity. Here, the natural state does not mean that the elastic ring is not elastically deformed, but means that the elastic ring is not driven by an external force.

Preferably, as shown in fig. 7-9, the hub body 144 is provided with a third receiving groove 145 for receiving said elastic ring 16, and a through groove 146 for receiving the elastic ring 16 entering said third receiving groove 145 from the side of the hub body, the through groove 146 communicating with the third receiving groove 145.

As shown in fig. 3, the base 11 includes a rod connecting section 111 for connecting with the rod 20, a front cover connecting section 112 for connecting with the front cover, and a flange boss 113 between the rod connecting section 111 and the front cover connecting section 112. The front end of the front cover connecting section 112 is provided with two first clamping grooves 115 which are symmetrically arranged, the inner wall of the front cover connecting section is provided with a limiting ring table 114 and a plurality of first guide blocks 117 which axially extend, the first guide blocks 117 are used for being matched with the first guide grooves 149 to realize the axial movement guiding of the needle base, and the outer wall of the front cover connecting section is provided with a first sealing groove 117.

In this embodiment, the hub 14 has a first position within the first space adjacent one end of the base and a puncturing position remote from the end of the base and is configured for axial movement between the first position and the puncturing position. As shown in fig. 19 and 20, in which needle holder 14 is located at the first position, needle holder 14 is maintained at the first position based on the action of first resilient member 17. Fig. 22 shows the needle hub in the puncturing position, in which the needle hub is advanced a distance from the first position to effect distal skin puncture, and an advancing space 50 is formed between the trailing end of the needle hub and the shaft.

In this embodiment, the first resilient member 17 is preferably a spring, and is disposed on the hub body between the stop ring 114 and the flange 148. The first elastic element 17 makes the needle seat keep at the first position, and is in a compressed energy storage state when the needle seat is located at the puncture position, so that after puncture is realized, the compressed potential energy of the first elastic element 17 is released, and the needle seat is driven to recover to the first position from the puncture position.

In this embodiment, the impact block 15 includes a first state attached to the impact cavity at the tail end of the needle seat and a second state separated from the tail end of the needle seat, when the impact block is in the second state, the elastic ring is stretched to store energy, and after potential energy generated by stretching of the elastic ring is released, the impact block moves from the second state to the first state under the driving action of the elastic ring and drives the needle seat to move from the first position to the puncture position through impact.

It should be noted that the drive mechanism in which the strike is driven out of engagement with the hub can be implemented in a variety of configurations, and this embodiment will show a preferred embodiment.

In the embodiment, the impact block is kept at the first position in the process of moving to the state to be triggered, so that the technical concept that the state of the needle seat can change along with the state to be triggered in armed equipment in the prior art is changed, the stroke of the needle seat is short, and the puncture stability and the puncture precision are higher. In the process of replacing the disposable blood taking needle, particularly in the process of installing the disposable blood taking needle, the needle seat is kept at the first position based on the structure limitation, the ineffective work of an elastic part is avoided, and the service life of the blood taking pen is prolonged.

In a preferred embodiment, the puncture depth of the disposable blood taking needle in the embodiment can be controlled. Specifically, an axial displacement adjustment mechanism is provided between the inner front cover 12 and the outer front cover 13.

In this embodiment, the structure of the inner front cover 12 shows two embodiments, which are shown in detail in fig. 2a, fig. 2b, fig. 4a and fig. 4 b.

The first embodiment, as shown in fig. 4a, includes an inner front cover body 121, an inner front cover flange 125 is disposed at a tail end of the inner front cover body 121, and a first latch 124 adapted to be connected to the first latch groove 115 is disposed on a side of the inner front cover flange 125 away from the inner front cover body 121. A pair of elastic arms 122 are oppositely arranged on the side wall of the inner front cover body 121, and a guide projection 123 facing one side of the outer front cover is arranged at the free end of the elastic arm 122.

In the present embodiment, a tapered body 126 is disposed at an end of the inner front cover body 121 away from the inner front cover flange 125, the tapered body 126 is provided with an end face 127, and the end face 127 is provided with a pinhole 128.

In this embodiment, the elastic arm 122 extends from a position close to the tapered body 126 to an end of the inner front cover flange 125 on the inner front cover body 121.

The second embodiment of this embodiment, as shown in fig. 4b, includes an inner front cover body 121, an inner front cover flange 125 is disposed at a rear end of the inner front cover body 121, and a first latch 124 adapted to be connected to the first latch groove 115 is disposed on a side of the inner front cover flange 125 away from the inner front cover body 121. A pair of elastic arms 122 are oppositely arranged on the side wall of the inner front cover body 121, and a guide projection 123 facing one side of the outer front cover is arranged at the free end of the elastic arm 122.

The difference between this embodiment and the first embodiment is that the end of the inner front cover body 121 away from the inner front cover flange 125 is open, and the tapered body 126 of the first embodiment is not provided. In this embodiment, the elastic arm 122 extends upward from the inner front cover flange 125 on the inner front cover body 121.

As shown in fig. 5 and 6, the outer front cover 13 of the present embodiment includes an outer front cover main body 131, and a piercing hole 133 is provided at the front end of the outer front cover main body 131, and similarly, a piercing hole corresponding to the position of the piercing hole 133 is provided at the front end of the inner front cover 12. Wherein, the inner wall of the outer front cover body 131 is provided with a guide groove 132 spirally extending along the axial direction, wherein the guide projection is connected with the guide groove in a matching way.

The elastic arm, the guide lug and the guide groove form an axial displacement adjusting mechanism between the inner front cover and the outer front cover in the embodiment. Under the condition that the relative position of the inner front cover is fixed, the axial displacement of the outer front cover relative to the inner front cover can be adjusted by rotating the outer front cover, and then the control of the puncture depth is realized.

Preferably, as shown in fig. 5 and 6, the guide groove 132 of the present embodiment is provided with a continuous stopper 135, and the stopper 135 is used to make the puncture depth have a clear shift position, so that the puncture depth can be controlled more accurately; especially, in the process of replacing the disposable blood taking needle, the outer front cover can be prevented from rotating relative to the inner front cover, and even if relative rotation occurs, the corresponding gear can be found quickly and quickly to recover quickly.

In addition, in this embodiment, as shown in fig. 2a, 2b, 3, and 6, in this embodiment, a limit block 118 is disposed on the flange boss 113 of the base 11, a limit groove 136 corresponding to the limit block is disposed at the bottom of the outer front cover 13, and the rotation stroke is limited in the process of controlling and adjusting the puncture depth by rotating the outer front cover. The two limit positions of the limit block in the limit groove correspond to the maximum and minimum puncture depths.

Preferably, the outer wall of the outer front cover of the embodiment is also provided with a puncture depth mark 134.

The rod 20 of the present embodiment, as shown in fig. 11, includes a first rod 21 and a second rod 22 connected in sequence, wherein the first rod 21, as shown in fig. 12, includes a first rod body 211, one end of the first rod body 211 is used for connecting with the base 11, and the other end is provided with a first rod connecting portion 216 used for connecting with the second rod 22. The first rod body 211 is provided with an air vent 215 penetrating through a sidewall of the first rod body, an inner partition 212 is disposed at an end of an inner side of the first rod body 211 adjacent to the second rod body, a first via hole 213 is disposed at a center of the inner partition 212, and a plurality of second guide grooves 214 extending from the first via hole in a radial direction are further disposed on the inner partition.

As shown in fig. 12, the second rod 22 of the present embodiment includes a second rod body 221, a second rod body connecting hole 222 for accommodating the first rod body connecting portion 216 is disposed at a front end of the second rod body 221, and a limiting step 223 is disposed at a hole bottom of the second rod body connecting hole 222.

In this embodiment, a plurality of axially extending protruding strips 224 are arranged on the inner wall of the second rod body 221 along the circumferential direction, an axially extending sliding slot 225 is formed between adjacent protruding strips 224, one end of the sliding slot 225 close to the first rod body is open, and one end close to the tail end of the second rod body is provided with a limiting portion 229. The top end of the protruding strip 224 is provided with a locking groove 228, one side of the locking groove 228 is provided with a first inclined surface 226, and the step surface of the locking groove 228 is a second inclined surface 227.

The drive mechanism in this embodiment, as shown in fig. 11, includes a piston 31, an adapter block 32, and a drive rod 33. As shown in fig. 14, the piston 31 includes a piston body 311, and a second seal groove 315 for mounting the seal ring 40 is provided on the piston body 311. A piston rod 312 is connected to one side of the piston body 31, the piston rod 312 can pass through the first through hole 213, and a guide rib 316 matched with the second guide groove 214 is provided on the piston rod 312.

In this embodiment, the piston rod is sleeved with a third elastic member 35, which is preferably a spring. In order to facilitate the installation and the limiting of the spring, the free end of the piston rod is provided with a pair of oppositely arranged elastic connecting arms 313, and the free ends of the elastic connecting arms are provided with limiting fixture blocks 314. When the third elastic piece is disassembled and assembled, the limiting clamping blocks are gathered towards the middle, and after the third elastic piece is assembled, the pair of limiting clamping blocks play a role in limiting the displacement of the third elastic piece.

As shown in fig. 15, the transfer block 32 of this embodiment includes a transfer block body 321, a plurality of first sliding blocks 323 adapted to the sliding groove 225 are axially distributed on the periphery of the transfer block body 321, a third inclined surface 324 is provided at the lower end of the first sliding block, and when the third inclined surface 324 acts relatively with the first inclined surface 226 and the second inclined surface 227, the transfer block is driven to move in an axial and circumferential direction. Wherein, the lower extreme of switching piece body is provided with switching connecting rod 322.

As shown in fig. 16, the driving rod 33 of this embodiment includes a driving rod body 331, a plurality of second sliding blocks 332 adapted to the sliding grooves 225 are distributed on an outer wall of the driving rod body 331 along a circumferential direction, a transfer connecting cavity 334 in clearance fit with the transfer connecting rod is arranged at an upper end of the driving rod body, and a plurality of tooth sockets 333 used for interacting with a bottom end of the first sliding block 323 are arranged on an upper end surface of the driving rod body along the circumferential direction.

As a special feature of the present embodiment, wherein the upper end of the piston body is provided with an adsorption block 34, the impact block is configured to be magnetically coupled with the adsorption block. In this embodiment, one of the striking block and the adsorbing block is made of a magnet material, and the other component is made of a material capable of being magnetically adsorbed by the magnet material.

The working process of the blood sampling pen comprises the following steps:

the method comprises the following steps: the front cover is separated from the base to replace the disposable lancet, and after the disposable lancet is replaced, the front cover and the base are attached again, and the attached state is as shown in fig. 17, 19, and 20.

Step two: promote the actuating lever, the actuating lever transmits effort to switching piece and piston in proper order, promotes the first slider roll-off spout on the switching piece, and at this moment, the one end of third elastic component is blockked by the interior baffle, and the other end is spacing by spacing fixture block, is in by compressed state.

And continuously pushing the driving rod, and under the double acting force of the pushing force and the third elastic piece, the third inclined plane of the first sliding block and the first inclined plane on the convex strip interact, so that the transfer block performs axial and circumferential combined motion until the lower end of the first sliding block falls into the clamping groove. Under this state, the lower extreme of first slider is spacing by the clamping groove, and the piston is in a relatively fixed position, and the third elastic component is in the compression energy storage state. Under the state, because the distance between the adsorption block and the impact block is short, under the action of suction force, the impact block moves to the adsorption block to be connected with the adsorption block in a suction way, and under the state, the elastic ring is stretched and is in a stretching energy storage state.

Thus, the blood sampling pen is in an armed state to be launched, and the schematic diagrams are shown in fig. 18 and 21.

And step three, the puncture hole of the front cover is tightly attached to the peripheral skin of the patient, so that the puncture hole and the skin are in a basically sealed state, and at the moment, the driving rod is pressed down, so that the puncture action can be finished.

The specific principle is that the driving rod is pressed to drive the third inclined surface of the first sliding block to interact with the second inclined surface, the transfer block performs axial and circumferential combined motion until the third inclined surface is separated from the second inclined surface, the first sliding block enters the sliding groove, and in this state, potential energy of the third elastic piece is released to drive the piston, the transfer block and the driving rod to recover to the initial state.

In the process of backward movement of the piston, when the suction force between the impact block and the adsorption block is smaller than the elastic pulling force of the elastic ring, the impact block is separated from the piston, the impact block quickly impacts on the needle seat under the action of the restoring force of the elastic ring, and the needle seat is driven by the impact force to move forward to the puncture position shown in fig. 22.

When the hub is in the puncturing position shown in fig. 22, the first resilient member is compressed to be in a charged state, and after puncturing, the first resilient member drives the hub to return to the first position.

The blood sampling pen of the embodiment has the characteristic of the process of forming negative pressure in the pressure change cavity. In this embodiment, the space between the front end of the piston and the puncture hole is a pressure change cavity, and a negative pressure environment is formed in the pressure change cavity in the process that the piston is triggered to move backwards from the armed state to be triggered, so that the peripheral skin at the puncture hole is sucked out of the bulge towards the pressure change cavity by the negative pressure environment.

In this embodiment, the negative pressure forming process at least includes:

in the first stage, the piston is under the effect of third elastic component, the in-process of backward quick motion, and the volume in pressure change chamber grow rapidly, and the pressure change chamber is isolated with external before the first stage begins, pressure in the pressure change chamber is equal with external atmospheric pressure, along with the change of pressure change chamber volume, the pressure change intracavity forms first negative pressure, first negative pressure lasts the grow along with the change of pressure change chamber volume.

In the second stage, when the piston moves to the state where the seal ring passes through the vent hole, the second stage of the present embodiment is formed, and in the second stage, the pressure change chamber is communicated with the outside through the vent hole.

And in the third stage, after the piston passes through the vent hole, the volume of the pressure change cavity is continuously increased, and in the volume increasing process of the pressure change cavity, the outside air continuously enters the pressure change cavity from the vent hole and forms second negative pressure.

When the piston returns to the initial state, namely after the volume of the pressure change cavity is increased to the extreme position, the outside air continuously enters the pressure change cavity through the vent hole under the action of pressure difference until the pressure in the pressure change cavity is equal to the outside pressure.

Preferably, in this embodiment, in the second stage, the volume of the pressure change cavity is equal to 0.2-0.8 times the maximum volume of the pressure change cavity.

In this embodiment, before the first stage of negative pressure formation starts, the lancet in the negative pressure lancet is in a state of waiting to be triggered, and a time node at which the lancet is triggered from the state of waiting to be triggered is after the first stage starts. When the blood taking needle is in a puncture state, the negative pressure forming process in the pressure change cavity is positioned from the second half of the first stage to the first half of the third stage. So that the blood in the skin bulge is gathered towards the puncture position, and the required blood can be conveniently collected at the puncture depth as shallow as possible.

In conclusion, the above description is only for the preferred embodiment of the present invention and should not be construed as limiting the present invention, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a negative pressure blood sampling pen, its characterized in that includes striking blood sampling device, the body of rod and actuating mechanism at least, striking blood sampling device includes at least:

-a base;

-a needle hub located within the first space;

-an impact block comprising at least a first state of abutment with the tail end of the needle hub and a second state of separation from the tail end of the needle hub, the impact block being connected to the needle hub by a second elastic member;

actuating mechanism includes the piston at least and sets up in the absorption piece of piston tip, the striking piece be configured into can with absorption piece magnetism is inhaled the formula and is connected, the piston is located in the body of rod and with body of rod axial swing joint, the space between piston front end and the puncture forms the pressure change chamber, the negative pressure formation process in the pressure change intracavity includes at least:

2. The negative pressure blood collection pen according to claim 1, wherein after the volume of the pressure change chamber is increased to the extreme position, the external air continues to enter the pressure change chamber by the pressure difference until the pressure in the pressure change chamber is equal to the external pressure.

3. The negative pressure blood collection pen according to claim 1, wherein the volume of the pressure change chamber is equal to 0.2 to 0.8 times the maximum volume of the pressure change chamber in the second stage.

4. A negative pressure lancet according to any of claims 1 to 3, wherein the lancet in the negative pressure lancet is in a cocked state before the first stage begins, and the time node at which the lancet is cocked from the cocked state is after the first stage begins.

5. The negative pressure lancet according to claim 4, wherein the lancet further comprises a puncture state in which the negative pressure forming process in the pressure varying chamber is located in the second half of the first stage to the first half of the third stage.

6. The negative pressure lancet according to claim 5, wherein the lancet is restored to an initial state after the puncture is performed.