Title:
SEPARABLE SURGICAL NEEDLE
United States Patent 3677243
Abstract:
A hollow surgical needle the shaft portion of which may be split in half longitudinally and the two mating halves of which are secured together with heat shrinkable material which includes two parallel score lines located externally of the band to facilitate tearing the band apart into two separate pieces so that the two halves of the needle can be removed from around a flexible tubular catheter having an enlarged fitting on one end after the other end of the catheter has been threaded through the hollow needle and is properly positioned in the patient.
US Patent References:
Expansile surgical needle
Richter - September 1951 - 2566499
Hypodermic needle for a cannula placement unit
Santomieri - July 1967 - 3330278
Venous catheter and needle
Rubin - May 1968 - 3382872
Guide needle for flexible catheters
Smith - December 1967 - 3359978
Expansile surgical needle
Richter - September 1951 - 2566499
Hypodermic needle for a cannula placement unit
Santomieri - July 1967 - 3330278
Venous catheter and needle
Rubin - May 1968 - 3382872
Guide needle for flexible catheters
Smith - December 1967 - 3359978
Application Number:
05/183572
Publication Date:
07/18/1972
Filing Date:
09/24/1971
View Patent Images:
Export Citation:
Primary Class:
International Classes:
A61M25/06
Field of Search:
128/214.4,221,347,348
Other References:
Dudrick et al. - "New Horizons for Intravenous Feeding" JAMA - Feb. 8, 1971 (pp. 939-49).
Primary Examiner:
Truluck, Dalton L.
Claims:
While the above described embodiment constitutes the presently preferred mode of practicing this invention, other embodiments and equivalents are clearly within the scope of the actual invention, which is claimed as
1. A surgical needle for performing medical operations having one end bevel sharpened for insertion in a patient and having at the other end an enlarged laterally protruding portion, an elongated hollow shaft portion therebetween comprising separate segments which mate together into an operable structure and also separate completely from each other in lateral fashion, at least one elongated band of flexible sterilizable plastic material laterally surrounding and extending axially along at least part of the shaft portion, the band being in tight engagement with the shaft portion and operating to secure the separate segments thereof together into an operable structure, and means including at least one weakened score line running lengthwise of the band to facilitate tearing it open for disengaging from the surgical needle to permit complete separation of the segments from each other in lateral fashion.
2. A surgical needle as in claim 1 wherein the band has two weakened score lines running lengthwise thereof to facilitate tearing it apart into two separate pieces.
3. A surgical needle as in claim 2 wherein the band is pre-separated along the score lines for a portion of its length to provide protruding portions to facilitate tearing it apart into separate pieces.
4. A surgical needle as in claim 3 wherein the end of the band nearest the sharpened end of the needle is bevelled, and the band is pre-separated along the score lines at its other end.
5. A surgical needle as in claim 1 wherein the band is of a heat shrinkable material.
6. A surgical needle as in claim 1 wherein the shaft portion is cylindrical and comprises two separate segments which mate together in a flat plane in which the longitudinal axis of the cylinder lies.
7. A surgical needle as in claim 6 wherein the enlarged laterally protruding portion comprises a single separate segment removable from the two separate segments of the hollow shaft portion, and the enlarged laterally protruding segment includes an internal cavity for receiving the ends of the two shaft portion segments.
8. A surgical needle as in claim 7 wherein the internal cavity is formed in an extension of the enlarged laterally protruding segment, and the band is in tight engagement with the extension to secure the two shaft portion segments with their ends in the internal cavity.
9. A surgical needle as in claim 8 wherein the band is pre-separated along score lines for a portion of its length adjacent the extension of the laterally protruding segment, the pre-separation providing protruding portions to facilitate tearing the band apart into separate pieces.
10. A surgical needle as in claim 9 wherein there are two score lines which are parallel and diametrically opposed to each other, and are located externally of the band of heat shrinkable material.
1. A surgical needle for performing medical operations having one end bevel sharpened for insertion in a patient and having at the other end an enlarged laterally protruding portion, an elongated hollow shaft portion therebetween comprising separate segments which mate together into an operable structure and also separate completely from each other in lateral fashion, at least one elongated band of flexible sterilizable plastic material laterally surrounding and extending axially along at least part of the shaft portion, the band being in tight engagement with the shaft portion and operating to secure the separate segments thereof together into an operable structure, and means including at least one weakened score line running lengthwise of the band to facilitate tearing it open for disengaging from the surgical needle to permit complete separation of the segments from each other in lateral fashion.
2. A surgical needle as in claim 1 wherein the band has two weakened score lines running lengthwise thereof to facilitate tearing it apart into two separate pieces.
3. A surgical needle as in claim 2 wherein the band is pre-separated along the score lines for a portion of its length to provide protruding portions to facilitate tearing it apart into separate pieces.
4. A surgical needle as in claim 3 wherein the end of the band nearest the sharpened end of the needle is bevelled, and the band is pre-separated along the score lines at its other end.
5. A surgical needle as in claim 1 wherein the band is of a heat shrinkable material.
6. A surgical needle as in claim 1 wherein the shaft portion is cylindrical and comprises two separate segments which mate together in a flat plane in which the longitudinal axis of the cylinder lies.
7. A surgical needle as in claim 6 wherein the enlarged laterally protruding portion comprises a single separate segment removable from the two separate segments of the hollow shaft portion, and the enlarged laterally protruding segment includes an internal cavity for receiving the ends of the two shaft portion segments.
8. A surgical needle as in claim 7 wherein the internal cavity is formed in an extension of the enlarged laterally protruding segment, and the band is in tight engagement with the extension to secure the two shaft portion segments with their ends in the internal cavity.
9. A surgical needle as in claim 8 wherein the band is pre-separated along score lines for a portion of its length adjacent the extension of the laterally protruding segment, the pre-separation providing protruding portions to facilitate tearing the band apart into separate pieces.
10. A surgical needle as in claim 9 wherein there are two score lines which are parallel and diametrically opposed to each other, and are located externally of the band of heat shrinkable material.
Description:
BACKGROUND OF THE INVENTION
The claimed invention relates to surgical instruments, and more particularly to hollow needles of the type used for positioning a catheter in a patient for one purpose or another, such as intra-venous feeding.
Prior to the present invention, hollow needles have been utilized in the medical and surgical fields to locate flexible tubular catheters in animal or human patients. In intra-venous feeding, to use an example, it has long been the practice to insert a hollow needle, approximately 2 inches long, into the patient's vein or vessel anteriorily at an acute angle. The needle is advanced a few mm. to insure that the entire bevelled tip of the needle is within the vessel lumen. A flexible tubular catheter is then inserted into the exposed end of the needle and threaded through the needle's full length. With the catheter tip thus in the vessel lumen, the hollow needle has served its purpose and is withdrawn back along the catheter until the needle is outside the patient, leaving the end of the catheter properly in place. The other end of the catheter is designed to be attached to a source of fluid to be introduced to the patient.
Proper disposition of the needle after it has performed its function and while the intra-venous feeding or other operation takes place, which may last a considerable length of time, has heretofore been a problem of no small significance. One early solution was to simply slide the needle back along and off the exposed end of the tubular catheter and remove it, and then attach the free end of the catheter to appropriate mechanical fittings which may in turn be secured to the container or other source of material to be introduced to the patient. This solution is not satisfactory, however, because the task of securing the fittings to the free end of the catheter utilizes valuable time of the medical staff -- which in some cases the patient can ill-afford -- and involves relatively rigorous manipulation of the free end of the catheter which may dislodge the other end from its proper location in the patient. Moreover, this manipulation seriously increases the ever-present danger of air being induced into the patient's blood stream.
To eliminate the necessity of attaching a fitting to the free end of the catheter after the other end has been inserted in the patient and the needle removed over the free end, medical supply houses have been supplying catheters with appropriate fittings integrally attached to one end. Such catheters save valuable time and eliminate many problems and have thus found favor with the medical profession, but they have created an additional problem. With the enlarged fitting on the end of the catheter, it is impossible to slide the hollow needle off the free end of the catheter once the needle is withdrawn from the patient. As a compromise, the medical staff in such instances slides the needle back along the catheter until the rear end of the needle is adjacent the enlarged fitting on the catheter and attaches the rear end of the needle to the fitting and/or wraps tape around the sharp end of the needle and catheter. The purpose of the tape is to prevent the needle from inadvertantly sliding back along the catheter and injuring the patient, and to prevent the catheter from pulling sideways abruptly at the sharp end of the needle, which could cut the catheter and destroy the operation.
To overcome this problem, other investigators have provided a hollow surgical needle which can be used to insert in a patient one end of a catheter having an enlarged fitting integrally associated with the other end, and can thereafter be removed from the catheter so as not to damage the catheter or the patient. This is accomplished by providing a hollow needle which is split in half longitudinally and the two mating halves are secured together in a detachable manner which permits the two halves of the needle to be removed from around the catheter after it is properly positioned in the patient. For instance, Santomieri U.S. Pat. No. 3,330,278 (July 1967) discloses a hypodermic needle for a cannula placement unit which is separable into two segments for the removal from the cannula, the two segments being secured together by means of a plug which is firmly fitted in place in a slot, plus if desired suitable adhesive may be used to bond the segments together. Smith U.S. Pat. No. 3,359,978 (December 1967) discloses a guide needle for flexible catheters which, in the FIG. 10 and 11 embodiments, comprises two separate segments secured together by inturned rolled edges adapted to slidably engage other rolled edges, and in the FIG. 11 embodiment they are secured together by flanges overlapping the edges of a U-shaped trough with a cement interposed therebetween. Rubin U.S. Pat. No. 3,382,872 (May 1968) discloses a venous catheter and needle, the latter consisting of separate segments secured together at their edges by gluing with an epoxy, soft soldering, or they may be defined by a pair of opposed longitudinally frangible lines.
But these attempts of skilled investigators to solve the needle removal problem were rendered obsolete, if indeed they ever experienced any commercial acceptance at all, by the invention of Robert J. Hassinger which involves the concept of utilizing a band of a heat shrinkable material to secure separate segments of the surgical needle together into an operational structure. This basic breakthrough is classic in its simplicity, and provided a clean and simple solution to a long standing problem which was welcomed by the medical and surgical professions despite their well-known high standards of perfection (see "New Horizons for Intravenous Feeding," Dudrick & Rhoads, JAMA, Feb. 8, 1971, pp. 939-49).
One disadvantage, however, encountered with the Hassinger invention is the removal of the band of heat shrinkable material from the hollow needle to permit separation of the needle segments from each other. Hassinger suggests as one possibility longitudinally cutting the heat shrunk material with a sharp instrument such as a scalpel to permit the separate segments of the needle to come apart for removal from the catheter. This procedure, however, requires the use of additional instruments for the careful cutting operation along the extremely narrow diameter needle, which is a delicate task at best.
Thus, the problem heretofore unsolved by the prior art is the provision of a band of material tightly securing separate segments of a surgical needle together into an operable structure wherein some quick and practical means is provided to remove the band and permit complete separation of the segments from each other in lateral fashion.
SUMMARY OF THE INVENTION
This invention provides a surgical needle having a hollow shaft which comprises separate segments which mate together into an operational structure and also separate completely from each other in lateral fashion, the separate segments being secured together by at least one band of material which is in tight engagement therewith, and at least one weakened score line running lengthwise of the band to facilitate tearing it open for disengaging from the surgical needle to permit complete separation of the segments from each other. In the preferred embodiment, the band is of heat shrinkable material and has two external weakened score lines, and the band is pre-separated along the two score lines for a portion of its length to provide two protruding "handle" portions to facilitate tearing it apart. The needle comprises separate segments which join together and are received in an internal cavity of an enlarged laterally protruding portion of the needle, the band also being in tight engagement therewith to secure the shaft portion segments with their ends properly received in the internal cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous advantages of the present invention will become apparent to one skilled in the art from a reading of the detailed description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts, and in which:
FIG. 1 is a view of the removable needle according to this invention with the bevelled tip inserted in a patent and one end of an elongated flexible catheter about to be inserted in the other end of the needle;
FIG. 2 is a view showing the catheter, with an enlarged mechanical fitting integrally associated with the free end, threaded through the needle and located in the patient, the needle being withdrawn back along the catheter until it is outside the patient;
FIG. 3 is a view showing the two separate segments of the hollow shaft portion of the needle laterally removed from the catheter, the enlarged laterally protruding portion of the needle moved back along the catheter, and the band of heat shrinkable material which was first torn apart into two separate pieces and removed from the needle;
FIG. 4 is a front end and elevational view of the needle according to this invention showing the two protruding portions which facilitate tearing it apart into two separate pieces;
FIG. 5 is a longitudinal sectional view of the needle according to this invention showing further details of its construction; and,
FIG. 6 is a lateral sectional elevational view on lines 6--6 of FIG. 5 showing the diametrically opposed external weakened score lines of the band.
DETAILED DESCRIPTION
Referring in more particularity to the drawings, a surgical needle 10 of this invention has an elongated hollow tubular shaft portion 12. One end thereof is sharpened by being bevelled as at 14, and the other end of the needle includes an enlarged laterally protruding portion 16 associated with the hollow shaft portion.
The needle is divisible into separate segments. In the presently preferred embodiment illustrated in the drawings, the elongated hollow shaft portion 12 is cylindrical, and comprises two separate segments which mate together in a flat plane, preferable the plane in which the longitidinal axis of the cylinder also lies. When the two halves of the shaft portion are mated together, the hollow center core 18 of the needle is designed and dimensioned to have a tubular catheter inserted therethrough.
The enlarged laterally protruding portion 16 comprises a single separate segment removable from the separate segments of the hollow shaft portion, and it includes an internal cavity 20 for receiving the ends of the two shaft portion segments. The internal cavity 20 is cylindrical in the illustrated embodiment, and is formed in an extension 22 of the enlarged segment 16. The internal cavity 20 includes an internal shoulder 24 against which the ends of the shaft portion segments are located when their ends are properly placed in the internal cavity.
To secure the three segments of the needle together into an integral, operational structure for inserting in a patient, disengageable means 26 are connected to secure the separate segments together when engaged and to permit complete separation of the segments when disengaged. The disengageable means comprises an elongated band 28 of material laterally surrounding at least part of the shaft portion 12, the band being easily disengaged therefrom. The forward edge of the band of material 28 may be bevelled as at 30, and the other edge of the band is in tight engagement with the extension 22 of the enlarged segment 16 to secure the two shaft portion segments with their ends in the internal cavity. Preferably, the band of material is a tube of known heat shrinkable material which, upon application of heat for a short period of time, contracts to tightly engage the elongated hollow shaft portion as well as the extension 22 to secure the three segments of the needle together into a unitary, operational structure. Bands of other material, such as silicone rubber molded directly into tight engagement with the needle, are also contemplated by this invention. This structure has the extremely important advantage of being air tight and leak proof, and it may be gas sterilized and/or autoclaved.
The band of surrounding material has at least one weakened score line, running lengthwise of the band, to facilitate tearing it open for disengaging from the surgical needle to permit complete separation of the segments from each other. With specific reference to FIG. 6, the preferred embodiment of this invention includes a band which has two weakened score lines 32 running lengthwise to permit tearing the band apart into two separate pieces. The two score lines 32 are parallel and diametrically opposed to each other, and are located externally of the band material. The non-bevelled end of the band is pre-separated along the two score lines for a potions of the length of the band to provide two protruding "handle" portions 34 to facilitate tearing the band apart. It will be noted that the band is in tight engagement with the extension 22 as at 36 to secure the two segments of the shaft portion 12 with their ends in the internal cavity 20, but the pre-separated portion which provides the two protruding portions 34 does not interfere with this function of the band.
The surrounding band, after the needle has served its purpose and been withdrawn from the patient along the catheter, is easily torn apart longitudinally into two separate pieces by grasping the protruding portions 34, as indicated in FIG. 2, and pulling to separate the band along the score lines, as indicated in FIG. 3. This permits the segments of the hollow shaft portion of the needle to be laterally removed from the catheter, and they may thereafter be discarded or may be preserved for re-use. The enlarged laterally protruding portion 16 of the needle is moved back along the catheter to a position of safety and non-interference.
Useful in conjunction with a needle constructed according to the foregoing is a catheter 38 comprising an elongated flexible tube 40 having one end 42 designed to be threaded through the hollow core 18 of the needle 10 and inserted in a patient. The other end of the catheter tube 40 has an enlarged mechanical fitting 44 integrally associated therewith. The fitting is designed for attachment to standard containers or other sources of material to be introduced into the patient. Preferably, the tubing 40 is made of medical grade silicon rubber, although catheters of teflon, polyethylene, vinyl and the like are also suitable.
Use of the removable catheter is apparent from the foregoing, which comprises inserting the bevelled end 14 of the hollow needle 10 into the patient, taking a catheter 38 having an enlarged fitting 44 integrally associated with one end, threading the other end 42 of the catheter through the hollow needle and locating it in place in the patient, sliding the needle 10 back along the catheter tube 40 without disturbing the located end 42 of the catheter until the needle is out of the patient, and then separating the needle into separate segments by grasping the protruding portions 34 of the band of material and tearing it apart along the longitudinal score lines 32, and thereafter removing the elongated hollow shaft portion segments from the internal cavity 20 and removing the hollow shaft portion segments from the catheter, all as is apparent from the foregoing description.
The claimed invention relates to surgical instruments, and more particularly to hollow needles of the type used for positioning a catheter in a patient for one purpose or another, such as intra-venous feeding.
Prior to the present invention, hollow needles have been utilized in the medical and surgical fields to locate flexible tubular catheters in animal or human patients. In intra-venous feeding, to use an example, it has long been the practice to insert a hollow needle, approximately 2 inches long, into the patient's vein or vessel anteriorily at an acute angle. The needle is advanced a few mm. to insure that the entire bevelled tip of the needle is within the vessel lumen. A flexible tubular catheter is then inserted into the exposed end of the needle and threaded through the needle's full length. With the catheter tip thus in the vessel lumen, the hollow needle has served its purpose and is withdrawn back along the catheter until the needle is outside the patient, leaving the end of the catheter properly in place. The other end of the catheter is designed to be attached to a source of fluid to be introduced to the patient.
Proper disposition of the needle after it has performed its function and while the intra-venous feeding or other operation takes place, which may last a considerable length of time, has heretofore been a problem of no small significance. One early solution was to simply slide the needle back along and off the exposed end of the tubular catheter and remove it, and then attach the free end of the catheter to appropriate mechanical fittings which may in turn be secured to the container or other source of material to be introduced to the patient. This solution is not satisfactory, however, because the task of securing the fittings to the free end of the catheter utilizes valuable time of the medical staff -- which in some cases the patient can ill-afford -- and involves relatively rigorous manipulation of the free end of the catheter which may dislodge the other end from its proper location in the patient. Moreover, this manipulation seriously increases the ever-present danger of air being induced into the patient's blood stream.
To eliminate the necessity of attaching a fitting to the free end of the catheter after the other end has been inserted in the patient and the needle removed over the free end, medical supply houses have been supplying catheters with appropriate fittings integrally attached to one end. Such catheters save valuable time and eliminate many problems and have thus found favor with the medical profession, but they have created an additional problem. With the enlarged fitting on the end of the catheter, it is impossible to slide the hollow needle off the free end of the catheter once the needle is withdrawn from the patient. As a compromise, the medical staff in such instances slides the needle back along the catheter until the rear end of the needle is adjacent the enlarged fitting on the catheter and attaches the rear end of the needle to the fitting and/or wraps tape around the sharp end of the needle and catheter. The purpose of the tape is to prevent the needle from inadvertantly sliding back along the catheter and injuring the patient, and to prevent the catheter from pulling sideways abruptly at the sharp end of the needle, which could cut the catheter and destroy the operation.
To overcome this problem, other investigators have provided a hollow surgical needle which can be used to insert in a patient one end of a catheter having an enlarged fitting integrally associated with the other end, and can thereafter be removed from the catheter so as not to damage the catheter or the patient. This is accomplished by providing a hollow needle which is split in half longitudinally and the two mating halves are secured together in a detachable manner which permits the two halves of the needle to be removed from around the catheter after it is properly positioned in the patient. For instance, Santomieri U.S. Pat. No. 3,330,278 (July 1967) discloses a hypodermic needle for a cannula placement unit which is separable into two segments for the removal from the cannula, the two segments being secured together by means of a plug which is firmly fitted in place in a slot, plus if desired suitable adhesive may be used to bond the segments together. Smith U.S. Pat. No. 3,359,978 (December 1967) discloses a guide needle for flexible catheters which, in the FIG. 10 and 11 embodiments, comprises two separate segments secured together by inturned rolled edges adapted to slidably engage other rolled edges, and in the FIG. 11 embodiment they are secured together by flanges overlapping the edges of a U-shaped trough with a cement interposed therebetween. Rubin U.S. Pat. No. 3,382,872 (May 1968) discloses a venous catheter and needle, the latter consisting of separate segments secured together at their edges by gluing with an epoxy, soft soldering, or they may be defined by a pair of opposed longitudinally frangible lines.
But these attempts of skilled investigators to solve the needle removal problem were rendered obsolete, if indeed they ever experienced any commercial acceptance at all, by the invention of Robert J. Hassinger which involves the concept of utilizing a band of a heat shrinkable material to secure separate segments of the surgical needle together into an operational structure. This basic breakthrough is classic in its simplicity, and provided a clean and simple solution to a long standing problem which was welcomed by the medical and surgical professions despite their well-known high standards of perfection (see "New Horizons for Intravenous Feeding," Dudrick & Rhoads, JAMA, Feb. 8, 1971, pp. 939-49).
One disadvantage, however, encountered with the Hassinger invention is the removal of the band of heat shrinkable material from the hollow needle to permit separation of the needle segments from each other. Hassinger suggests as one possibility longitudinally cutting the heat shrunk material with a sharp instrument such as a scalpel to permit the separate segments of the needle to come apart for removal from the catheter. This procedure, however, requires the use of additional instruments for the careful cutting operation along the extremely narrow diameter needle, which is a delicate task at best.
Thus, the problem heretofore unsolved by the prior art is the provision of a band of material tightly securing separate segments of a surgical needle together into an operable structure wherein some quick and practical means is provided to remove the band and permit complete separation of the segments from each other in lateral fashion.
SUMMARY OF THE INVENTION
This invention provides a surgical needle having a hollow shaft which comprises separate segments which mate together into an operational structure and also separate completely from each other in lateral fashion, the separate segments being secured together by at least one band of material which is in tight engagement therewith, and at least one weakened score line running lengthwise of the band to facilitate tearing it open for disengaging from the surgical needle to permit complete separation of the segments from each other. In the preferred embodiment, the band is of heat shrinkable material and has two external weakened score lines, and the band is pre-separated along the two score lines for a portion of its length to provide two protruding "handle" portions to facilitate tearing it apart. The needle comprises separate segments which join together and are received in an internal cavity of an enlarged laterally protruding portion of the needle, the band also being in tight engagement therewith to secure the shaft portion segments with their ends properly received in the internal cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous advantages of the present invention will become apparent to one skilled in the art from a reading of the detailed description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts, and in which:
FIG. 1 is a view of the removable needle according to this invention with the bevelled tip inserted in a patent and one end of an elongated flexible catheter about to be inserted in the other end of the needle;
FIG. 2 is a view showing the catheter, with an enlarged mechanical fitting integrally associated with the free end, threaded through the needle and located in the patient, the needle being withdrawn back along the catheter until it is outside the patient;
FIG. 3 is a view showing the two separate segments of the hollow shaft portion of the needle laterally removed from the catheter, the enlarged laterally protruding portion of the needle moved back along the catheter, and the band of heat shrinkable material which was first torn apart into two separate pieces and removed from the needle;
FIG. 4 is a front end and elevational view of the needle according to this invention showing the two protruding portions which facilitate tearing it apart into two separate pieces;
FIG. 5 is a longitudinal sectional view of the needle according to this invention showing further details of its construction; and,
FIG. 6 is a lateral sectional elevational view on lines 6--6 of FIG. 5 showing the diametrically opposed external weakened score lines of the band.
DETAILED DESCRIPTION
Referring in more particularity to the drawings, a surgical needle 10 of this invention has an elongated hollow tubular shaft portion 12. One end thereof is sharpened by being bevelled as at 14, and the other end of the needle includes an enlarged laterally protruding portion 16 associated with the hollow shaft portion.
The needle is divisible into separate segments. In the presently preferred embodiment illustrated in the drawings, the elongated hollow shaft portion 12 is cylindrical, and comprises two separate segments which mate together in a flat plane, preferable the plane in which the longitidinal axis of the cylinder also lies. When the two halves of the shaft portion are mated together, the hollow center core 18 of the needle is designed and dimensioned to have a tubular catheter inserted therethrough.
The enlarged laterally protruding portion 16 comprises a single separate segment removable from the separate segments of the hollow shaft portion, and it includes an internal cavity 20 for receiving the ends of the two shaft portion segments. The internal cavity 20 is cylindrical in the illustrated embodiment, and is formed in an extension 22 of the enlarged segment 16. The internal cavity 20 includes an internal shoulder 24 against which the ends of the shaft portion segments are located when their ends are properly placed in the internal cavity.
To secure the three segments of the needle together into an integral, operational structure for inserting in a patient, disengageable means 26 are connected to secure the separate segments together when engaged and to permit complete separation of the segments when disengaged. The disengageable means comprises an elongated band 28 of material laterally surrounding at least part of the shaft portion 12, the band being easily disengaged therefrom. The forward edge of the band of material 28 may be bevelled as at 30, and the other edge of the band is in tight engagement with the extension 22 of the enlarged segment 16 to secure the two shaft portion segments with their ends in the internal cavity. Preferably, the band of material is a tube of known heat shrinkable material which, upon application of heat for a short period of time, contracts to tightly engage the elongated hollow shaft portion as well as the extension 22 to secure the three segments of the needle together into a unitary, operational structure. Bands of other material, such as silicone rubber molded directly into tight engagement with the needle, are also contemplated by this invention. This structure has the extremely important advantage of being air tight and leak proof, and it may be gas sterilized and/or autoclaved.
The band of surrounding material has at least one weakened score line, running lengthwise of the band, to facilitate tearing it open for disengaging from the surgical needle to permit complete separation of the segments from each other. With specific reference to FIG. 6, the preferred embodiment of this invention includes a band which has two weakened score lines 32 running lengthwise to permit tearing the band apart into two separate pieces. The two score lines 32 are parallel and diametrically opposed to each other, and are located externally of the band material. The non-bevelled end of the band is pre-separated along the two score lines for a potions of the length of the band to provide two protruding "handle" portions 34 to facilitate tearing the band apart. It will be noted that the band is in tight engagement with the extension 22 as at 36 to secure the two segments of the shaft portion 12 with their ends in the internal cavity 20, but the pre-separated portion which provides the two protruding portions 34 does not interfere with this function of the band.
The surrounding band, after the needle has served its purpose and been withdrawn from the patient along the catheter, is easily torn apart longitudinally into two separate pieces by grasping the protruding portions 34, as indicated in FIG. 2, and pulling to separate the band along the score lines, as indicated in FIG. 3. This permits the segments of the hollow shaft portion of the needle to be laterally removed from the catheter, and they may thereafter be discarded or may be preserved for re-use. The enlarged laterally protruding portion 16 of the needle is moved back along the catheter to a position of safety and non-interference.
Useful in conjunction with a needle constructed according to the foregoing is a catheter 38 comprising an elongated flexible tube 40 having one end 42 designed to be threaded through the hollow core 18 of the needle 10 and inserted in a patient. The other end of the catheter tube 40 has an enlarged mechanical fitting 44 integrally associated therewith. The fitting is designed for attachment to standard containers or other sources of material to be introduced into the patient. Preferably, the tubing 40 is made of medical grade silicon rubber, although catheters of teflon, polyethylene, vinyl and the like are also suitable.
Use of the removable catheter is apparent from the foregoing, which comprises inserting the bevelled end 14 of the hollow needle 10 into the patient, taking a catheter 38 having an enlarged fitting 44 integrally associated with one end, threading the other end 42 of the catheter through the hollow needle and locating it in place in the patient, sliding the needle 10 back along the catheter tube 40 without disturbing the located end 42 of the catheter until the needle is out of the patient, and then separating the needle into separate segments by grasping the protruding portions 34 of the band of material and tearing it apart along the longitudinal score lines 32, and thereafter removing the elongated hollow shaft portion segments from the internal cavity 20 and removing the hollow shaft portion segments from the catheter, all as is apparent from the foregoing description.