CN208808747U - A kind of valve clamping machine - Google Patents

Abstract

The utility model discloses a kind of novel valve clamping machines, including the first nip part, the second nip part and fixation member for fixing the first nip part and the second nip part, first nip part has at least two first clamping arms, second nip part has the second clamping arm of corresponding number, and the second corresponding clamping arm of each first clamping arm can be combined to a pair of of fixture.The fixation ring design of the top design of smooth transition, the design of the clip tooth of high clamping stability and " line is dual-purpose " can be used in the clamping machine, on the one hand clamping machine is reduced during the motion to the damage of valve, on the other hand valve is captured convenient for user, it reduces and improves clamping performance while damage to valve, furthermore the overall structure highly processable of this clamping machine is manufactured convenient for producer.

Description

A kind of valve clamping machine

Technical field

The utility model relates to a kind of valve clamping machine more particularly to a kind of valve folders for treating heart valve regurgitation Clutch.

Background technique

Bicuspid valve is attached to the two panels valve (as shown in Figure 1) of left atrioventricular orifice periphery, is connected in papillary muscle by means of chordae tendineae, there is prevention The blood of left ventricle flows back to the effect of atrium sinistrum.

Mitral regurgitation (MR) is organic or function occurs due to mitral valve leaflet and its dependency structure to sexually revise to lead to two Leaf coincide bad before and after cusp, and blood flow flows backward to atrium sinistrum from left ventricle, causes a series of pathophysiological change.Serious MR meeting Cause left room to expand, eventually leads to left systolic heart failure obstacle and heart failure, while left atrial pressure also increases because of reflux Greatly, Left atrium enlargement, atrial fibrillation and pulmonary hypertension are easy to cause.MR prognosis is poor, has symptom and non-row operator annual death rate 5% or so, and there is serious 5 annual death rate of heart failure person up to 60%.Meanwhile MR is also one of most common heart disease.According to system Meter, the disease incidence more than 65 and 75 years old crowd is respectively 6.4% and 9.3%.With economic society development and population it is old Age, the disease incidence of mitral regurgitation are in the situation obviously risen.

Clinical test shows that drug therapy can only improve patient symptom, and cannot extend survival of patients or opportunity of operation.Outside Section's surgical valve reparation or displacement technique are considered as the standard treatments of the disease, have been shown to reduction of patient symptom and Extend its service life.However, surgical operation has the shortcomings that wound is big, postoperative pain is obvious, it is slow to restore, risk is high, in addition, some There are out chest medical history, poor heart function at advanced age and merge the infull patient of multi-organ function often since surgical risk is refused greatly Exhausted surgical operation.Therefore, researching and developing minimally invasive, low-risk, treatment MR intervention therapeutic apparatus has great social profit and city Field demand.In recent years, as valve interventional therapeutic technique obtains breakthrough development, the intervention apparatus of MR has become the country at present One of the emphasis direction of outer cardiovascular devices research and development.

Wherein, the valve clamp instrument that foundation surgical valve edge researches and develops edge suturing skill principle is because of safety Height, technical principle are simple, feasibility is big at present most by certainly.Surgery valve edge is as shown in Figure 2 to edge suturing skill principle: two When cusp reflux, two leaflet edges of paradoxical expansion can not pairing closing there is gap, cause the blood flow of left ventricle from gap Return to atrium sinistrum；Surgery edge sutures by two leaflet edge intermediate point sutures of bicuspid valve, so that leaflet when paradoxical expansion edge Between gap two apertures are become by a macropore, to reduce mitral regurgitation (Fig. 2 a), and diastole mitral valve open When flow into left ventricle blood flow again unaffected (Fig. 2 b).The minimally invasive intervention apparatus of unique granted listing treatment MR is in the world The MitraClip of Evalve company is exactly a kind of valve jaw device.But it contains complicated control system, production and production Cost it is also very high；The instrument needs finally to reach left ventricle through vein, atrium dextrum, atrial septum, atrium sinistrum during operation, and road enters way Diameter is not only long but also many places are bent, therefore surgical procedure is extremely complex, and doctor needs fine tuning transportation system camber repeatedly, direction, level Position, vertical depth can just clamp valve after reaching ideal position, therefore doctor is frequently necessary to take a long time, could be complete Cheng Yitai operation, this disadvantage are denounced deeply.

By the exclusive patent CN106175986A of Zhongshan Hospital Attached to Fudan Univ's exploitation, our company disclose a kind of device and The relatively simple valve clamping machine of application method finds, which still exists by actual production and performance test results Many defects such as capture valve difficulty is big, may cause valve damage, clamping power is difficult to be promoted.

Therefore, those skilled in the art is dedicated to developing a kind of novel valve clamping machine, in traditional version clamping machine On the basis of, it is on the one hand reduced during the motion to the damage of valve, on the other hand captures valve convenient for user, and improve Its clamping performance, while facilitating production, improve its processability.

Utility model content

In view of the above drawbacks of the prior art, the technical problem to be solved by the utility model is to provide one kind to have more Add the valve clamping machine of excellent using effect and production realizability.

In order to achieve the above object, the utility model provides a kind of valve clamping machine for treating MR, the clamping machine is through minimally invasive MR can be effectively treated after Operative approch implantation human body.

The valve clamping machine specifically includes the first nip part, the second nip part and for fixing first clamping The fixation member of component and second nip part, first nip part has at least two first clamping arms, described Second nip part has the second clamping arm of corresponding number, corresponding second clamping of each first clamping arm Arm can be combined to a pair of of fixture, the distal end of at least part the first clamping arm along the clamping direction of the first clamping arm to It is provided with the first protrusion outside and is inwardly provided with the second protrusion, the first clamping arm has several phases with the second clamping arm The clip tooth mutually cooperated.

In the case where not illustrating, " distal end " described in the utility model refers to that the valve clamping machine is conveyed Far from one end of operator after entering in human body, " proximal end " described in the utility model refers to that the valve clamping machine is conveyed into One end of proximal operator is leaned on after in human body, " inside " described in the utility model is directed to the side that each component center line is drawn close To " outside " described in the utility model refers to the direction far from each component center line.

In a preferred embodiment of the utility model, which is set as the shape of femoral head end Shape is provided with protrusion along clamping direction and opposite direction, while the second clamping arm distal end is likewise provided as having second to prolong The flared structure of semi-girder.Therefore, when completing clamping, the first positive protrusion can be with the ball on the second adjutage top of outreach The cooperation of shape part, realizes even closer clamping.Simultaneously because the presence of the second reversed protrusion, the first clamping arm will not be outside Continue to draw close to center under the action of addition of constraints power, to limit the relative position of device distal end.At this point, passing through collar shape Fixation member continues the second nip part of banding, will be so that generating elastic deformation on the first clamping arm, the second clamping arm and generating The elastic stress to contend with additional restraining force, which will transmit in each inter-module, and step up device overall co-ordination more It is close, it is more stable for the clamping performance of valve.

Preferably, first nip part distal end be set as curved surface, corner be provided with round-corner transition plane or with Upper two kinds have the combination seamlessly transitted.

Further, the sandwich serface of the first clamping arm distal end is set as fan-shaped surface.Herein, sandwich serface refers to folder The reversed plane for closing direction, approximatively can be understood as the contoured surface in i.e. clamping arm side view.

Further, the setting direction of the clip tooth of the first clamping arm proximally tilts.

Further, several clip tooths of the first clamping arm are along the first clamping arm by proximal end to distal direction Discrete setting, and the length of each clip tooth is in the distribution changed from small to big along proximal end to distal direction.

Further, the fixation member includes being internally provided with the set ring region of the several first fixed teeth, second folder Closing arm has several the second fixed teeth with the described first fixed tooth cooperation, is inserted in second folder by changing the set ring region The opening angle of second nip part can be changed in the depth for closing component, and solid by the described first fixed tooth and described second The cooperation of fixed tooth is fixed.

Further, the fixed tooth of described first be arranged inside the set ring region is internal thread structure, second folder The proximal end for closing component is additionally provided with the external screw thread cooperated with the internal thread structure.

Further, the fixation member is substantially in tube-in-tube structure, and its proximal end barrel is than distal end adjacent thereto Barrel is thin.Lantern ring proximal end is relatively thin, for realizing the connection between delivery pipe.

Further, the fixation member is made using polyether-ether-ketone, high density polyethylene (HDPE) or combinations thereof.

Further, the second nip part distal end is set as spherical shape, ellipsoid, the cube with round-corner transition The combination with smooth transition of two or more shape of shape or any of the above.This is to the second nip part distal end shape Enumeration restriction should be understood as that the end face is set as not including or containing substantially no three-dimensional defined by the curved surface of any wedge angle Figure further includes 3-D graphic and the above-mentioned combination enumerated that such as hyperboloid, streamlined plane curved surface limit.Airflow design Be conducive to the smooth walking in delivery sheath, while valve will not be damaged because of the presence of wedge angle, solves conveying and device peace The problem of full property.

Further, which is characterized in that second nip part also has the second adjutage, second adjutage with The second clamping arm is in 110~150 degree of angles and expansion outward.In the present invention, expansion is and nip part outward Main shaft middle line in contrast, expansion extends to the direction far from main shaft middle line outward.

Further, the length of second adjutage is 3~5mm.

Further, the second clamping arm is the narrow structure in the wide proximal end in distal end.

Further, the valve clamping machine is made of the material with high support strength, especially by having strong reply The elastic alloy material of power is made, such as Nitinol.

Further, the clip tooth of the first clamping arm is long pointed tooth, and the clip tooth of the second clamping arm is short cognate.The The clip tooth of one clamping arm is more sharp, elongated, and the clip tooth of the second clamping arm is short and blunt, this is because when operation, the first clamping Arm is located at atrium, and the second clamping arm is located at ventricle, and ventricular side has many chordae tendineaes and atrial surface does not have, in order to same in increase clamping power When be avoided that again clip tooth damage ventricle inside chordae tendineae, take such design.

Compared with prior art, the technical solution of the utility model has the advantage that

When completing clamping, the first positive protrusion can cooperate with the spherical shape part on the second adjutage top of outreach, Realize even closer clamping.And the presence of the second reversed protrusion, so that the first clamping arm will not be in the work of outer addition of constraints power Continue to draw close to center under, to limit the relative position of device distal end, makes each component in clamping machine inside during clamping Cooperate it is even closer, it is more stable for the clamping performance of valve.

First nip part distal end is curved-surface structure, does not contain any wedge angle, is conducive to the smooth walking in delivery sheath, Simultaneously valve will not be damaged because of the presence of wedge angle.Therefore the curved design solves asking for conveying and equipment safety simultaneously Topic.In addition, distal side is set as fan-shaped, convenient for fixation of the valve in sewing process, while overlay film is conducive to quick endothelium Change.

Clip tooth is set as proximally tilting, convenient for being fixed valve using clip tooth when capture valve, is prevented because valve is sliding It is inconvenient caused by de- or fixed shakiness.In addition, clip tooth is proximally gradually increased to distal dimension, sandwich part can effectively ensure that More preferable fitting and stronger bite force between part, promote clamping stability.

Using the fixed nip part of thimble structure, the ability that clamping arm clamps valvular tissue can be further increased, and institute The valvular tissue clamped is drawn close to intermediate clamping.The thimble structure upper section contains screw thread, can be with second sandwich part The screw thread of the proximal end setting of part matches, to play the role of fixing the second nip part.In addition, thimble structure upper section contains Screw thread can be used as the first fixed tooth and the fixed tooth of the second sandwich part second is mutually fitted matching, is inserted in by changing the set ring region The opening angle of second nip part can be changed in the depth of second nip part.In this way, fixation member internal screw thread rises To the effect of " line is dual-purpose ".

Set the V-type extended out for the second nip part head, top be set as spherical shape or analogous shape without wedge angle Shape, such design is so that the second nip part is not likely to produce stress concentration point during capturing valve, and subtended angle is bigger, It easily realizes the capture to valve, while making it smaller to the damage of valve without pointed design.In addition, the second clamping Arm is wide at the top and narrow at the bottom, convenient for fixation of the valve in sewing process.

Make furtherly below with reference to technical effect of the attached drawing to the design of the utility model, specific structure and generation It is bright, to be fully understood from the purpose of this utility model, feature and effect.

Detailed description of the invention

Fig. 1 is cardiac anatomy schematic diagram；1 is superior vena cava in figure, and 2 be inferior caval vein, and 3 be atrium dextrum, and 4 be three Cusp, 5 be right ventricle, and 6 be pulmonary valve, and 7 be pulmonary artery, and 8 be pulmonary vein, and 9 be atrium sinistrum, and 10 be bicuspid valve, and 11 be the left heart Room, 12 be aorta petal, and 13 be aorta, and 14 be descending aorta, and 15 flow to for oxygenated blood, and 16 flow to for anoxemia；

Fig. 2 a and Fig. 2 b are surgery bicuspid valve edge to edge suturing skill schematic diagram, and when wherein 2a is mitral valve closure, 2b is When mitral valve open；

Fig. 3 a is the structural schematic diagram front view of the first nip part in a preferred embodiment of the utility model；

Fig. 3 b is the structural schematic diagram side view of the first nip part in a preferred embodiment of the utility model；

Fig. 4 a is the structural schematic diagram front view of the second nip part in a preferred embodiment of the utility model；

Fig. 4 b is the structural schematic diagram side view of the second nip part in a preferred embodiment of the utility model；

Fig. 5 is the structural schematic diagram cross-sectional view of the fixation member in a preferred embodiment of the utility model；

Fig. 6 is the operation principle schematic diagram of the valve clamping machine in a preferred embodiment of the utility model.

Appended drawing reference: the first nip part of 30-, 301- the first clamping arm, the first clip tooth of 302-, the first protrusion of 303-, The second protrusion of 304-, the fan section 305-；The second nip part of 40-, the second clip tooth of 401-, 403- ball top, 404- second extend Arm, 405- external screw thread, the fixed tooth of 406- second；50- fixation member, 501- internal screw thread, 502- delivery pipe junction.

Specific embodiment

This gives a kind of follow-on for treating the valve clamping machine of mitral regurgitation, the valve clamping machine With the first discrete nip part 30, the second nip part 40 and for being removably secured the first nip part 30 and second The fixation member 50 of nip part 40.Wherein, respectively arranged first folder on the first nip part 30 and the second nip part 40 It closes arm 301 and the second clamping arm constitutes a pair of of fixture, the two can be made to draw close and squeeze valve therein by external force, to reach To the purpose of clamping.

It is each in the utility model to understand in depth below by way of the detailed description to each functional assembly in the present embodiment The purpose and effect of component design.

Valve clamping machine in the present embodiment using the clamping arm worked in coordination on nip part to clamp valve, in order to mention High clamping arm prevents the valve clamped from slipping the clamping ability of valve, and the valve clamping machine in the present embodiment is in clamping arm Clamping valve position be provided with detent projection, as in Fig. 3 a and Fig. 3 b on the first nip part 30 the first clip tooth 302 and The second clip tooth 401 with the cooperation of the first clip tooth 302 in Fig. 4 a and Fig. 4 b on the second nip part 40.Wherein, the first clip tooth 302 Using thorn-like pointed tooth, which can be pierced into valvular tissue, reinforce the first clip tooth 302 for the crystallized ability of valve.In addition, first The bayonet fittings that clip tooth 302 is arranged proximally tilt, and capture when with the use of the first nip part 30 and the second nip part 40 When valve, partially valve can be fixed using bayonet fittings, prevent valve from slipping or fixing shakiness, reduce operator and catch Obtain the difficulty of valve.In addition, the set-up mode of the first clip tooth 302 on the first nip part 30 are as follows: proximally to distally prolonging Size is gradually increased on the direction stretched.Since the opening angle of the second clamping arm of usual second nip part 40 is typically larger than The opening angle of one clamping arm 301, if therefore setting equal length for all clip tooths and may make on the first nip part 30 The clip tooth of distal end can not be bonded the second clamping arm, cause the situation that clamping is unstable.Therefore, the first clip tooth 302 in the present embodiment Set-up mode can effectively ensure that the bite force between nip part, promote the stability of valve clamping.The clip tooth of first clamping arm It is more sharp, elongated, and the clip tooth of the second clamping arm is short and blunt, this is because the first clamping arm 301 is located at atrium when operation, Second clamping arm is located at ventricle, and ventricular side has many chordae tendineaes and atrial surface does not have, in order to be avoided that increasing clamping power simultaneously Clip tooth damages chordae tendineae inside ventricle, takes such design.

Another unique design of valve clamping machine in the present embodiment is 30 head of the first nip part using having Bilateral convex shape without pointed design.Wherein to referred to as the first protrusion 303 of protrusion on the outside of clamping machine, first protrusion 303 Main function be to cooperate the ball design more closely clamping valve of 40 distal end of the second nip part, realize between folder up and down Seamless clamping.Meanwhile on the 30 distal end other side of the first nip part, that is, the direction to come closer, it is additionally provided with second Protrusion 304, the main function of second protrusion 304 is, when pushing close ring tightening folder up and down, the second protrusion 304 is mutually Relative position at the top of the second clamping arm of restriction, can only be by the second clamping when continuing tightening so that pressing from both sides up and down The bending of arm realizes that, since the second clamping arm is supported using elastomeric alloy such as iron-nickel alloy, elastic deformation generates elasticity and answers Power, to produce the internal stress so that each member in tight fitting of clamping machine, the internal stress.

In addition, first nip part 30 also passes through more curved surfaces while designing the first protrusion 303 and the second protrusion 304 The mode of smooth transition, so that 30 distal end of the first nip part exists with the position that valve and sheath contact without wedge angle.In this reality It applies in example, 30 tip designs of the first nip part are the biomimetic features of similar human femur under loading cephalic par, and the sawtooth design is on the one hand It ensure that user is more smooth when nip part is conveyed into inside of human body using sheath, on the other hand also ensuring will not Because the presence of wedge angle generates the injury for valve.Meanwhile from side view, the top of nip part is set on sandwich serface It is calculated as fan section 305, which can be using the concave inward structure of its engaging portion two sides and the protrusion of top two sides in sewing process Preferably secure valve, while overlay film can be advantageously implemented quick endothelialization thereon.

Similarly, the top of the second nip part 40 equally uses no pointed design, using spherical shape design in the present embodiment, It is reduced during the motion to the damage of valve.Different from the first nip part 30, the second nip part 40 is in order to more Valve is captured well, needs to expand the top subtended angle of the second clamping arm.If will lead to but from the bottom bend of the second clamping arm On the one hand clamping arm entirety flare is relatively difficult to be inserted in, separately when push fixation member 50 is locked folder up and down for operator On the one hand it is unfavorable for the clamping stability of upper and lower ogival sections.Therefore, it uses in the present embodiment in the second clamping arm tip flexion, or It is interpreted as increasing the mode of the second additional adjutage 404, improves the top subtended angle of the second clamping arm.In the present embodiment, The angle α of second clamping arm and the second adjutage 404 is about 140 degree, the length about 3mm of the second adjutage 404, which protects It is internal when in use and will not generate stress concentration to valve to have demonstrate,proved the second adjutage 404, ensure that the second nip part 40 The damage to valve is reduced while intensity；Subtended angle bigger simultaneously is conducive to the capture in surgical procedure to valve, facilitates behaviour Make.

In the present embodiment, as is shown in figures 3b and 4b, the fixation for the ease of valve in sewing process, the first clamping Component 30 and the second nip part 40 are preferably wider using top, the relatively narrow structure in bottom.

Fig. 5 and Fig. 6 further illustrate the structure of fixation member 50 and the fixation member 50 in the present embodiment be as What the first nip part 30 of cooperation and the second nip part 40 realize the close clamping to valve.As shown in figure 5, this reality It applies the clamping machine provided in example to fix using close ring mode, is the thimble structure with internal screw thread 501 at the top of the close ring, it should On the one hand internal screw thread 501 can cooperate with 405 structure of external screw thread of 40 bottom of the second nip part, for fixing close ring and the On the other hand two nip parts 40 can cooperate with the second fixed tooth 406 in 40 middle part outside of the second nip part, limit the second folder Close the arm opening angle of component 40.Close ring bottom is thinner, is delivery pipe junction 502.It should be noted that the second sandwich part Second fixed 406 structure of tooth in 40 middle part outside of part is typically designed to anisotropic structure, i.e., the proximal end of each fixed tooth is adopted With obtuse angle domatic, Caton phenomenon will not be generated when pushing close ring, and distal end uses right angle or acute angle domatic, so that close ring When completing push, it will not make to fix between internal screw thread 501 and the second fixed tooth 406 because of skidding unstable.

When conveying the second nip part 40 with close ring, close ring can be first passed through to 405 structure of internal and external threads with second It connect, is transported at the valve of distal end with delivery pipe after clamping is fixed, after valve to be captured, screw close ring and pass through the second folder The thread segment of component 40 is closed, and further push close ring to its internal screw thread 501 and the second fixed tooth 406 partially overlaps.At this point, Valve will be pulled to center and tighten, and the position for going deep into the second nip part 40 by adjusting internal screw thread 501 adjusts nip part Between subtended angle and clamping power, to optimize the clamping state of valve.As shown in fig. 6, final valve clamping state answers stress Balanced, appropriate, top is close using the first protrusion 303 of the first nip part 30 and the ball top 403 of the second nip part 40 Ground clamping valve, middle part utilize the thorn-like clip tooth secure valve of the first nip part 30, and outside is solid using the restraining force of close ring Clamp clutch single unit system, entire clamping process stability and high efficiency injure valve smaller.

In the present embodiment, the quantity of clamping arm is two groups, in other preferred embodiments, can also use three groups or three Clamping arm more than group captures the structure of valve jointly.It will be understood by those skilled in the art that the quantity of the clamping arm can basis The actual conditions of patient select in operation.

The preferred embodiments of the present invention have been described in detail above.It should be appreciated that the ordinary skill people of this field Member according to the present utility model can conceive without creative work makes many modifications and variations.Therefore, all this technology necks Technical staff passes through logic analysis, reasoning or limited reality according to the design of the utility model on the basis of existing technology in domain Available technical solution is tested, it all should be within the scope of protection determined by the claims.

Claims (14)

1. a kind of valve clamping machine, which is characterized in that including the first nip part, the second nip part and for described in fixation The fixation member of first nip part and second nip part, first nip part have at least two first clampings Arm, second nip part have the second clamping arm of corresponding number, corresponding described of each first clamping arm Second clamping arm can be combined to a pair of of fixture, at least partially folder of the distal end of the first clamping arm along the first clamping arm It closes direction to be provided with the first protrusion outward and be inwardly provided with the second protrusion, the first clamping arm and the second clamping arm have There are several mutually matched clip tooths.

2. the setting direction of valve clamping machine as described in claim 1, the clip tooth of the first clamping arm proximally tilts.

3. valve clamping machine as described in claim 1, which is characterized in that the first clamping arm distal end is set as curved surface, turns Plane or both the above that round-corner transition is provided at angle have the combination of smooth transition.

4. valve clamping machine as described in claim 1, which is characterized in that the sandwich serface of the first clamping arm distal end is set as Fan-shaped surface.

5. valve clamping machine as described in claim 1, which is characterized in that several clip tooths of the first clamping arm are along described One clamping arm by proximal end to the discrete setting of distal direction, and the length of each clip tooth is in by small along proximal end to distal direction The distribution to become larger.

6. valve clamping machine as described in claim 1, which is characterized in that the fixation member includes being internally provided with several the The set ring region of one fixed tooth, the second clamping arm have several the second fixed teeth with the described first fixed tooth cooperation, pass through Change the set ring region and be inserted in the depth of second nip part and the opening angle of second nip part can be changed, and leads to The cooperation for crossing the described first fixed tooth and the described second fixed tooth is fixed.

7. valve clamping machine as claimed in claim 6, which is characterized in that described first be arranged inside the set ring region is fixed Tooth is internal thread structure, and the proximal end of second nip part is additionally provided with the external screw thread with internal thread structure cooperation.

8. valve clamping machine as claimed in claim 6, which is characterized in that the fixation member is substantially in tube-in-tube structure, and Its proximal end barrel is thinner than distal end barrel adjacent thereto.

9. valve clamping machine as described in claim 1, which is characterized in that the fixation member uses polyether-ether-ketone, high density Polyethylene or combinations thereof is made.

10. valve clamping machine as described in claim 1, which is characterized in that the second nip part distal end is set as ball Shape, ellipsoid, the cubic with round-corner transition or any of the above two or more shape have a smooth transition Combination.

11. valve clamping machine as described in claim 1, which is characterized in that second nip part also has the second extension Arm, second adjutage and the second clamping arm are in 110~150 degree of angles and expansion outward.

12. valve clamping machine as claimed in claim 11, which is characterized in that the length of second adjutage is 3~5mm.

13. valve clamping machine as described in claim 1, which is characterized in that the second clamping arm is that the wide proximal end in distal end is narrow Structure.

14. valve clamping machine as described in claim 1, which is characterized in that the clip tooth of the first clamping arm is long pointed tooth, institute The clip tooth for stating the second clamping arm is short cognate.