GB2283918A

GB2283918A - Gas-propelled trocar needle

Info

Publication number: GB2283918A
Application number: GB9421632A
Authority: GB
Inventors: Marc Waisman
Original assignee: WAIS MED Ltd
Current assignee: WAIS MED Ltd
Priority date: 1993-11-18
Filing date: 1994-10-27
Publication date: 1995-05-24
Also published as: FR2712480A1; DE4440045A1; IL107650A0; CA2134245A1

Description

2283918 LLED SURGICAL INSTRUMENT FOR IMPACT GAS-PROPE INSERTION OF

INTicAOSSEOUS TRO1CAR-NEEDLE

BACKGROUND OF THE INVENTION

The invention relates to a surgical instrument for impact insertion Gf a trocar-needle into a bone for the purpose of infusion, injection, transfusion, aspiration, anesthesis or any other drug delivery or treatment of patients, be they human beings or animals. It relates particuldrly isertion of a S i to. 1, f., n ir to an instrument sulit-II-Ile for instantaneou trocar-needle, be it. n a battle Field, t 11 e accident, r, r a n Y, - i -, h,.. r cc c a s i c, n w,"i e r c, j ri s. t a n 1 an, L. c. u s infusion or injection i:,.,-:comes necessary. '. 1. is especially necessary in tn e c d of n e w - b o r n, e s r, r c h i 1 L' r e n A c r e; t is of.Len.1i-i"fictilt to find a vein. In the case of ad u 11.1 s i t L).-,- e s an alLernative to intravenous infu.)ii-jn or injection as a Y.51Pid access and for bone ra a r i,,:, w aspiration or -1, r a n s p 1 t u. t j c. n..

Intraosseous i n f u. -,- i on, and b o ne marrow transfusion were f i rst irit)-oduc,.d i,. j,,urties of tr, is century, and t-.,ere espec i al Jy used i n cases during World War 11, to avoild the lenct.h. d i ng the suit,6,1, g, t il -s for f 1 0 bt 1 ood vessel for i i;.. er 1. 10 n ol: the needle. the method is well known, but nol, riatich in use, becatise of the diff iculty to forcefully drive a needle or a trocar into the bone with resulting great pain, on the one hand, and the danger of inf-ction owing to the necessity to provide an opening through the skin and the tissue surrounding +t..he bone. The conventional trocar used is in the for.m of a sharp stylet enclosed;n a tube (cannula) and Inserted through the containing wall,f the bone, whereafter the stylet is withdrawn permitting fluid to be infused or to 10 be drained through the tube.

Infusion injection, resuscil.3t!on, delivery of drugs and anesthels,s through a major vein or peripheral vein may often cause com'iic,,tionr, which,,..n easily be avoided by intraosseouss infusion, and it is th-e mnain object of the -ially designed trocar is present invention to provide a spec needle and an instrurTtit which will drive or shoot it into the marrow of a Lone without causing pain to the patient.

bpecial cases where bone injection becomes necessary are for rapid vasculdr access, injection of dru,s and aspiration of bone marrow.

It is another ohiect to provide an instrument for the above purposes, w1hich is practically foolproof and easil_,! handled by any surgeon, nurse, medic or paramedic in the 3 battlefield, as well as in ambulances, and especially in the emergency room of a hospital.

Still another object is to provide a surgical instrument which can be readily sterilized for re-use, but the main idea is to produce it at low cost so as to permit its disposal after a single use.

SUMMARY OF THE INVENTION

In the following description of the surgical instrument it should be noted that the expression "fronC will be used for tihe end of the instrument to be pres-d onto the skin of the patient, and that the expression llrearll for the other end, and that the expression "forward" and "rearward" will be used in the same sense.

It should also be noted that the surgical instrurcent of the invention i s being used f or trea t",rierit cif s ick - or heal-i.iiy - persons, of new-borne; children, of horses cattle, and of any living being in need of treatment, that in the following the expression "patient" will used in short to include all the ebove.

a, fl (1 but be 4 - The surgical instrument or "gun" serving to drive a trocar-needle into a bone of a patient works on the principle that the rear end of the trocar- needle is releasingly attached to the front end of a piston which is driven in forward direction by gas released from a compressed gas bottle, both piston and gas bottle being positioned insiJe the instrument. The gas bottle is normally closed by a valve which is opened by pressure oF the front end of the gun onto the skin of the patient, after a safety catch has been released, thereby driving the trocar-needle in forward direction at high velocity and releasinn it trow its hold on the piston.

AS shown in Figure, the instrument includes a trocarneedle which has the external shape of a conventional is hypodermic needle, whereof the front end is in Ce form of a sharp point 21 closing the lumen 23 of the needle and forming communication between the lumen and the outside by one or more transverse holes 22 in the tube wall close to the sharp point. The rear end of the needle is formed, again in a conventional manner, by a flange 20 serving for its attachment to an infusion set or the like.

A preferred embodim,nt of the instrument or "gun" includes essentially:- A cylindrical housing having a front end 1 - closed by a perforatable membrane for keeping the need-le in sterile state, and having a rear end closed by an axially movable plug. The housing contains the aforedescribed trocar-needle with its sharp point close to the membrane, a piston releasably holding t,:,e needle end by flexible grips attached to the front end of the piston, and a cylinder surrounding the piston and forming an integral part of the housing.]he rear end of the cylinder has an opening connecting the outlet end of a valve body which normally keeps the gas bottle closed. The gas bottle is held in its normal, rearward position by a safety pin thereby preventing inadvertent shooting of the needle which is thus firmly held in its rearward possition. The plug is provided with a catch holuing it in its forward is position against gas pressure acting on the front of the cylinder.

The "gi;.n" is prepared for action by pul ling the sdf ety pin whi.rh permits forward movement of the gas bottle; in order to drive or. to shoot the trocar-needle into the predesig- nated bone,, the front end of the housing is pressed aga!nst the relevant skin covering the bone by hand pressure on the slidable plug at the rear end; -,he plug moves forward and simultaneously pushes the gas bottle in the same direction, causing the valve body to enter the bottle and to open it. Gas flows out into the cylinder at high pressure driving the piston and the attached trocar- -ion through the needie at great velocity in forward direct membrane, through the skin and tissue into the bone. The piston is, at the end of the travel, stopped by an inwardly extending flange at the end of the cylinder, causing the resilient grips at the piston front to release the trocar-needlels rim. The housing is now withdrawn and the trocar-needle is connected to an infusion set or a sy,inge by means o'lF' its rim outside the patient'-- body.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a longitudinal section of the surgical instrument or gun, in cocked position, Figure 2 is an enlarged drawing of the central p7jrtion, Figure 3 is a longitudinal section of the tror;r.-neeULe of the invention, arid, Figure 4 is a of the trocar longitudinal section of a second embodimen.L needle.

7 LETAILED-DEISCRIPTION OF THE DRAWINGS The trocar-needle ilustrated in Figure 3 has the external shape of a conventional hypodermic needle 23 with the he lumen 24 stops short off the sharp difference that t front end 21 and communicates with the outside - in the present case the bone interior - through 4.

bores 22. The rear end of the needle is in the form of a circumferential rim 20 for connection to a syringe, an infusion set or the like.

The trocar needle illustrated in Figure 4 comprises a solid stylet 25 which has a sharp front end 21 and a rear end mounted in a cylindrical block 26 which tilpers tow.trds its front end. The stylet is enclosed in a carnitle 27 which includes a hollow frusto-conical rear end 28 which is is fitted on the front end of block 26 and terminates in a circumferential rim 20 identical with that shown in Figure 3 and serving the same purpose.

The instrument or "guC for driving or shooting the trocar-needle illustrated in Figures 3 or 4 into a Pdtient's b on e f c, r infusion, transfusion and other treatment includes essentially a housing 1, a trocer needle 2 releasably held by a piston 3, and a gas bo.,,,tle 4. The housing has its front end closed by a membrane 5 which is firmly and tightly attached to the housing by a cenzrally perforated cap 10 which serves as a stopper preventing accidental shooting of the trocar- needle. Its rear end is closed by a movable plug 14 which is provided with a spring-operated catch 15. The front portion of the housing is formed in the shape of a smooth cylind;.,r 11 the - end of which is provided with an inwardly protruding front 1 collar 12 serving as frort- Stop for the piston 3.

is The central portion of the medical instrument illustrated in detail in Figure 2, and in the following reference will be made to this figure only. The housing incILdes a parti+,.i,...ii 13 forming the rear wall of the cylinder, centrally perforated by a gas inlet opening 16. To the rear of the partition the houAng forrt- a smooth cylindrical guide 17 for the iront end of the valve housing of the gas bottle permitting ready motion of the latter in forward direction.

The piston 3 is in the form of a disc 30 extendea tr the front by an axle 31 which has its front end perforated bv -N rear end a cylindrical recess 35 configured to receive 41. of the trocdr needle iilustrated in Figure 4. The d:sk and the axle are made of metal -to give the nee-dle the necessary impetus. The axle carries aL its front end another disc 32 of a plastic material which comprises two or more hook-shaped, elastic grips 33 which attach the trocar needle to the piston by means of its rear flange 20 (v.Fig.3 and 4) and release it upon sudden contact of the piston with the collar 12. A ring seal 34 is inserted into a circum- ferential groove on the periphery of disc 30 preventing gas from escaping.

The gas bottle contains compressed air or another suitable gas and is closed by a valve body 40 axially mov;.ble in a valve housing 41. The valve housing is fastened in the tapped neck of the bottle and is provided with two parallel circumferential grooves 42 and 43, of whico the latter contains a ring seal 44 serving to prevent gas from is penetrating into the rear portion of the housing. Groove 43 engages the end of a sdfety pin 45 which has a ball shaped handle protruding out of the housing. The valve housing is centrally perforated and contains a valve in the form of a tube 46 closed at its rear end by a flange le 47 and communicating, in opened state, with the bot-L interior by means of one or more lateral openj:;,s 48. In closed state of the gas bottle as shown in the drawing the openings are covernd by the valve housing. Additional closure is effected by a gasket 48 positioned between the rear end of the valve housing arid the flange 47 Whi C h i.> urged onto the housing end by the pressure of tte gas in the bottle.

As mentioned before, the instrument is prepared for the "shoC by withdrawing the safety pin 45 out of the housing. The front end is now pressed onto thz.; skin the + 1 :,--rated by t roc needle covering the bone to be penl and the gas bottle is pushed forward by pressure onto plug 'ug being lied in its 14 at the end of the housing, the pA position by safety catch 15. Forward motion of the bottle urges the valve body inwardly thereby uncovering openings 48 and effecting communication between the bottle interior and the cylinder. Gas pressure drives the piston and the attached needle forwdrd at great speed, the needle being is pushed through the membrane into the patient'--) body into the bone. The is 5..opped by collar 12, whereu,-,on 1 the needle is re,'eased from the piston by the flexible grips 33.. Now the instrument is removed and the needle connected to a syringe,, an infusion or transfusion set.

The main advantage of the invention is the rapid introduction of the trocar-needlle into the bone, almost without -antaneous release from pain to the patient, and its inst the shooting device. This method is preferable to intra- jP - 1 1 - venous infusion, since it takes so less time than finding the suitable blood vessel, a fact that is most important in the field, during accidents, riots and similar conditions. As mentioned above, it is very usefull with newbornes and children, where it is often difficult to detect the vein. Since the instrument is completely sterile there is no danger of infection or, other complications.

It will be understood that the mechanism for driving the gas from the gas bottle into the ear of the cylinder as shown and described herein before, is only one way of moving the bottle in forward direction and that any other mechanism may be conceived and carrried into effect by a person skilled in the art. Similarly the shape of the is housing, the piston and the other components may be modified as long as the method of shooting a trocar ilkedle into a bone is maintained.

12 - C L A 1 M S 1. A surgical instrument for forcefully driving a trocar needle into the bone marrow of a patient through the skin and the tissue, by the force of release of initially compressed gas, the instrument comprising, - and a rear and a longitudinal housing hdving a front being divided by a centrally perforia-ted partition into a frontal portion and into a rear portion, said frontal portion forming 9 cylinder containing a PiS'L'on movable therein and a trocar-needle releasably attached to the front of said piston, and said rear port.-on containing a compressed gas bottli and means for causing said bottle to be opened, thereby rel?asing compressed gas into said cylinder and effecting said piston and said trocar needle to be driven in forward direction, said rear portion fur-ther containing is,,,ans for effecting said trocai- needle to be released fr-(m said piston at the end of said piston's stroke after hL..-ing penetrated into said bone.

Claims

2. The surgical i n strument of Claim 1 ' where 1 n said trocar-needle is

in the shape of a conventional hypodermic needle positioned in the front of said housing with its shai-p end poink'.i,,i,, towards the front, said trocar-reedle i 13 - being characterized by a sharp closed point and by at least one transverse hole close to said sharp point serving as communication with the needle bore and the outside.

3. The surgical instrument of Claim 1, wherein said trocar-needle includes a sharp stylet which is firmly connected to the front end of said piston,, said stylet being enclosed in a cannule and having a rear end releasably mounted in the rear end of said stylet and terminating in the form of a circumferential rim.

4. The surgical instrument of Claim 1, wherein said gas bottle includes a valve body axially movable in a valve housing and protruding out of said hodsing in forward direction, with its front end in close relationship to said perforation in said partition, said valve body keeping said bottle closed in its forward position and opening it while being pushed rearwardly in-,,.o said bottle.

5. The surgical instrument of Claim 4, wherein said valve body is in the shape of a tube closed at its rear end by a flange and being perfn.rated by at least one transverse 14 - opening at its rear end close to said flange, and wherein the front end of said tube cooperates with said perforation in said partition.

6. The surgical instrument of Claim 4, wherein the rear end of said housing contains a plug which is axially movable by manual pressure exerted thereon effecting said bottle to be moved in forward direction, said valve body to be pressed into said bottle, thereby opening said bottle and effecting gas to flow out of said bottle through said valve body into said cylinder and to drive said piston and said trocar needle in forward direction.

7. The surgical instrument of Claim 5, wherein said piston is provided with resilient grips adapted to hcld the rear rim of said trocar-needle and to release it after insertion of said trocar into the bone.

8. The surgical instrument of Claim 1, wherein said housing is of cylindriral shape having its front end closed by a perforatable membrane held in position by a centrally pei^forated cap.

9. The surgical instrument of Claim 6, wherein said plug is provided with a spring-loaded catch to hold it in its forward position.

10. The surgical instrument of Claim 1, wherein said piston includes a rear portion of metal in the form of a disc and a forwardly extending axle and a frontal disc of a plastic material fastened to said axle, said frontal disc being provided with elastic grips of plastic material for releasably holding said circumferential rim of said trocar needle.

11. The surgical instrument of Claim 10, wherein said metal disc of said piston is provided with a sealing ring mounted in a circumferential groove.

12. The surgical instrument of Claim 5, wherein En annular gasket is placed on the frontal surface of said flange of said valve body, ensuring tight closure of said boLtle.

13. The surgical instrument of Claim 4, wherein said v1 alve housing is provided with a circumferential groove engaging the pin of a safety catch extending from the - 16 outside of said housing and holding said gas bottle in its rearward position during non-use.

14. The surgical instrument of Claim 1, wherein said houing is made of a plastic material.

15. The surgical instrument of Claim 1, wherein said housing is made of a metal.

16. The surgical instrument of Claim 2, wher-_.in said trocar needic is provided with two opposed laterall holes close to said sharply pointed front end.

17. The sur,,ical instrument as claimed in any of Claims 1 through 16 and substantially as described with reference to the accompanying drawings.