FRONT-LOADING MEDICAL INJECTOR
AND SYRINGE FOR USE THEREWITH
CROSS-REFERENCE TO RELATED
APPLICATIONS 5
This application is a continuation of application Ser. No. 08/901,602, filed on Jul. 28, 1997, now U.S. Pat. No. 5,997,502, which is a continuation of application Ser. No. 08/780,012, filed on Dec. 23, 1996, now U.S. Pat. No. 5,741,232, which is a continuation of application Ser. No. 10 08/359,087, filed on Jan. 19,1995, now abandoned which is a division of application Ser. No. 07/929,926, filed on Aug. 17, 1992, now U.S. Pat. No. 5,383,858, the contents of which are hereby incorporated by reference.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a front-loading medical injector and a syringe for use therewith, and more particularly to a 2Q front-loading medical injector apparatus wherein a syringe of special construction is mountable upon and removable from a front wall of an injector housing by a first readily releasable mechanism, while a plunger in the syringe is simultaneously connected to or dissembled from an injector 2J drive member by a second readily releasable mechanism.
2. Description of the Prior Art
U.S. Pat. No. 4,006,736, issued to R. J. Kranys et al. on Feb. 8,1977, and entitled, "Angiographic Injector", which is assigned to the same Assignee as the subject application, 30 discloses an angiographic injector apparatus for injecting contrast media into the vascular system of an animal, in which angiographic syringes are rear-loaded into a pressure jacket of the injector. More specifically, the apparatus comprises a rotatable turret which carries a pair of the pressure 35 jackets and which is rotatable so that when one of the pressure jackets, into which an angiographic syringe has been rear-loaded, is in an injection position, the other pressure jacket is in a position in which an associated angiographic syringe can be rear-loaded. Subsequently, 40 when injection of contrast media from the first syringe is completed, the turret is rotated to move the first syringe to an unloading-loading position, with the second pressure jacket and the angiographic syringe then being moved into the injection position. In this apparatus, when each of the 45 pressure jackets and its associated syringe has been located in the injection position, a drive member of the injector is moved forward to become drivingly engaged with a plunger in the syringe; however, the manner of engagement between the drive member and plunger is such that the drive member 50 cannot be retracted without also retracting the plunger, which can cause body fluids of the animal to be retracted into the syringe unless the syringe is first disconnected from the animal.
An improved apparatus over the apparatus as disclosed in 55 the Kranys et al. patent, is disclosed in U.S. Pat. No. 4,677,980, issued to D. M. Reilly et al. on Jul. 7, 1987, and entitled "Angiographic Injector and Angiographic Syringe for Use Therewith", which also is assigned to the same Assignee as the subject application. In this apparatus, a drive 60 member of the angiographic injector can be drivingly connected to, or disconnected from, a plunger of an angiographic syringe at any point along the path of travel of the plunger by a readily releasable mechanism. Thus, the apparatus of the Reilly et al. patent represented certain improve- 65 ments over the Kranys et al. patent. However, the apparatus of the Reilly et al. patent, like that of the Kranys et al. patent,
is of a rear-loading type comprising a pair of pressure j ackets mounted upon a rotatable turret for moving the pressure jackets and syringes therein between injection and loading positions.
Accordingly, a need exists for a front-loading medical injector and a syringe of special construction so that the syringe can be readily and securely front-loaded directly and accurately in a desired position on the injector, thereby facilitating the loading-unloading operation, and a primary purpose of this invention is to provide such an arrangement with its various attendant advantages. Further, in certain instances, it is desirable that the syringe not be enclosed in a pressure jacket, in order that an operator be able to view the status of the syringe visually during an injection operation. By allowing the operator to see the syringe, the operator can, e.g., determine whether the syringe is empty or full, determine if it is being filled too fast and/or introducing too many air bubbles, when the syringe is filled, and the amount of contrast that has been delivered or remains in the syringe during a procedure. Another purpose of this invention is, in one embodiment, to provide an injector apparatus of such construction.
SUMMARY OF THE INVENTION
In general, in accordance with the invention, a readily releasable mechanism is provided for supporting a syringe on a front wall of an injector housing for an injection operation. For this purpose, the readily releasable mechanism includes at least one retaining portion on the mounting mechanism releasably engageable with a mating retaining portion on the syringe. Further, an actuating mechanism of the injector includes a drive member which is connectable to a plunger in the syringe for controlling the movement of the plunger in the syringe.
More specifically, the readily releasable mechanism is an interlocking mechanism which is activated and released upon rotation of a rearward portion of the syringe relative to the front wall of the injector housing. At the same time, a second readily releasable interlocking mechanism for connecting the injector drive member to the syringe plunger, and which also is activated and released upon rotation of the syringe relative to the front will of the housing, interconnects the drive member and the plunger. The first readily releasable mechanism may comprise a mounting mechanism on the front wall of the housing having at least a pair of slots for receiving retaining flanges on the rearward end of the syringe therethrough, with the syringe then being rotated to engage the flanges behind associated retaining flanges of the mounting mechanism. The second readily releasable mechanism comprises respective radially projecting parts on the drive member and the plunger which become drivingly engaged in a similar manner upon rotation of the syringe and the plunger.
The first readily releasable mechanism may be further defined by the mounting mechanism on the injector housing front wall having an annular sealing member against which a resilient annular sealing member on the syringe becomes seated as the syringe is positioned on the mounting mechanism, with the resilient annular sealing member and the retaining flanges on the syringe receiving the retaining flanges on the mounting mechanism therebetween with an interference fit. An audible-and-tactile indicator mechanism, alignment arrows, and/or alignment dots also may be provided to detect when the syringe has been essentially rotated into its desired mounted position against suitable stops, with this mechanism then further functioning to discourage
reverse rotation of the syringe on the injector housing. An indicator mechanism for providing liquid media injection information to an injector controller, and a sensor for reading the indicating mechanism, also may be provided on the syringe and the injector housing, respectively. The syringe 5 also may include a mechanism which provides a visual indication of whether the syringe still includes injection liquid, may have an injector nozzle of reduced diameter surrounded by a screw-threaded cylindrical attachment portion at its injection end (the reduced diameter nozzle serving to minimize the amount of contrast that remains in the syringe after the plunger has been fully extended), may be provided with reinforcing ribs which are longitudinally spaced so as to also function as volumetric gradations, and/or may be formed of relatively strong clear plastic.
In another embodiment of the invention, which utilizes a pressure jacket, the pressure jacket is in the form of an elongated tube having one end mounted on the front wall of the injector, housing, and having an opposite open outer end. In a syringe mounting operation, a syringe is inserted into 2Q the open end of the tubular jacket until an inner end of the syringe engages against a seat mechanism on the injector housing front wall. During this insertion operation, retaining flanges adjacent the forward end of the syringe pass through slots in the open end of the tubular pressure jacket, where- 2J upon the syringe is rotated to engage the flanges behind corresponding mating retaining flanges at the open end of the jacket. As the syringe is rotated, a plunger in the syringe also rotates into driving engagement with a drive member of the injector. An outer injection end of the syringe also may 3Q be provided with reinforcing-handle members.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial, isometric view of an injector apparatus in accordance with the invention, showing an injector hous ing and a syringe in disassembled relationship;
FIG. 2 is an enlarged isometric view of portions of the apparatus shown in FIG. 1, more specifically illustrating certain features of the invention;
FIG. 3 is a partial, cross-sectional view, taken essentially 4Q along the line 3—3 in FIG. 1, illustrating the injector housing and the syringe in assembled relationship;
FIG. 4 is an end view, as seen essentially along the line 4—4 in FIG. 1, illustrating features of the syringe;
FIG. 5 is an isometric view of a modified form of the 45 syringe shown in FIG. 1;
FIG. 6 is an enlarged isometric view of the syringe shown in FIG. 1, illustrating another feature of the invention;
FIG. 7 is an isometric view of portions of the apparatus shown in FIG. 1 in a different orientation, illustrating a 50 further feature of the invention;
FIG. 8 is a cross-sectional view taken essentially along the line 8—8 in FIG. 1, illustrating another feature of the invention;
FIG. 9 is an isometric view similar to FIG. 1, illustrating 55 an embodiment of the invention utilizing a pressure jacket, with an injector drive member and a syringe plunger in a retracted loading position; and
FIG. 10 is an isometric view similar to FIG. 9, illustrating the apparatus of the pressure jacket embodiment with the 60 injector drive member and the syringe plunger in an advanced loading position.
DESCRIPTION OF THE DISCLOSED
EMBODIMENTS
FIG. 1 discloses a injector apparatus 20 of the general type disclosed in the U.S. Pat. No. 4,006,736 to R. J. Kranys
et al. and U.S. Pat. No. 4,677,980 to D. M. Reilly et al, for injecting a liquid contrast media into a vascular system of an animal, but of front-loading construction, rather than rearloading construction, as disclosed in those patents. Thus, the apparatus of FIG. 1 utilizes a syringe 22 capable of being front-loaded into a mounting assembly 23 on. a front wall 24 of a housing 26 of an injector 27 by a first readily releasable mechanism 28, and also capable of functioning in a injection operation without the use of a pressure jacket, whereas each apparatus of those patents is of a type in which angiographic syringes are rear-loaded into respective pressure jackets supported on a rotatable turret for moving the jackets between injection and loading positions. However, to the extent not inconsistent with this disclosure, the disclosures of those two patents, which both are assigned to Medrad Inc, of Pittsburgh, Pa., the Assignee of the subject application, are hereby incorporated by reference.
With reference to FIGS. 1-3 and the first readily releasable mechanism 28, the mounting assembly 23 on the front wall 24 of the injector housing 26 is provided with an essentially cylindrical opening 29 for receiving a rearward end of the syringe 22. The opening 29 includes a pair of upper and lower slots 29s (best shown in FIG. 2) through which respective upper and lower retaining flanges 22/ of the syringe 22, having reinforcing ribs 22fr, may pass as the rearward end of the syringe is inserted in the opening. The mounting assembly 23 further includes opposed retaining flanges 23/ on opposite sides thereof so that, after the rearward end of the syringe 22 has been inserted into the opening 29, and the syringe is rotated clockwise, as viewed in FIG. 1, the retaining flanges 22/ on the syringe become engaged behind the retaining flanges 23/ to secure the syringe to the housing front wall 24. During this mounting of the syringe 22 on the housing front wall 24, the rotation of the syringe preferably is limited by suitable rearwardly projecting stops 30 at adjacent ends of the housing front wall retaining flanges 23/ The mounting assembly 23 also includes an inner annular ring 31 in spaced relationship to the retaining flanges 23/ to provide support for the rearward end of the syringe 22 and also define semi-annular guide slots 23s (best shown in FIG. 2) for receiving the syringe flanges 22/
As is disclosed in the aforementioned D. M. Reilly et al U.S. Pat. No. 4,677,980, and referring again to FIG. 1, the syringe 22 comprises an elongated main tubular body or barrel 32 and a coaxial discharge injection section 34, interconnected by an intermediate conical portion 36. A plunger 38 is slidably positioned within the tubular body 32 and is connectable to an actuating mechanism 40 in the injector housing 26 by a second readily releasable mechanism 42. The second readily releasable mechanism 42 is formed in part by the plunger 38 comprising a base member 43 having hook or lug members 44 (FIGS. 1, 3 and 4) extending rearwardly therefrom, with portions 46 of these members extending radially inward in opposed relationship. The plunger 38 serves to control the ejection of fluid contained within the syringe 22 in a desired quantity and at a desired rate, and the hook members 44 are designed to facilitate axial movement of the plunger in either direction when connected to the actuating mechanism 40 by the second readily releasable mechanism 42.
Further in this connection, as is best shown in FIGS. 2 and 3, the actuating mechanism 40, which reciprocates the plunger 38 in the syringe tubular body 32, comprises a reciprocable drive member 48 which includes a base portion 50, a stem 52 (FIG. 3) and an integral rectangular head 54 extending radially outward from the stem, all of which form
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