Front load pressure jacket system with syringe holder

Abstract: A pressure jacket system of the invention is used to permit the front loading and removal of a syringe (214) from an injector (20), and includes a jacket cylinder (216) having an open front end (218) for receiving a syringe (214) and a rear end coupled to the injector front face (23), first and second tie rods (238, 240) having rear ends pivotly attached to the injector front face (23) by pivots and bushings (230, 234, 232, 236), and a front retaining plate (222) attached to the front ends of the first and second tie rods (238, 240), such that the retaining plate (222) and tie rods (238, 240) are pivotable between a closed position for holding the syringe (214) within the jacket cylinder (216) and an open position to allow the insertion and removal of the syringe (214) from the jacket cylinder (216).

Description: This invention relates to pressure jacket systems for securing a syringe in an injector head. More specifically, the invention relates to pressure jacket systems which allow front loading and removal of a syringe, and which hold the syringe securely to an injector head during injection procedures. BACKGROUND OF INVENTION In the medical field, patients often are injected with fluids in procedures such as angiography. In such procedures, which require controlled injection of a large volume of fluid into a patient, a needle is used as a conduit for the fluid which is connected to the syringe by a connector tube. The syringe is mounted on a motorized injector having an injector head. For long term compatibility with injectable fluids, syringes may be made of polypropylene with a certain minimum wall thickness. The thickness is critical as typical pressures of up to 82 bars (1200 p.s.i) are used to inject the fluids into a patient. For safety and sanitary reasons, different disposable syringes are used for different fluids and different patients. Pressure jackets are known in the art for enclosing and retaining syringes while in use. A pressure jacket serves to limit radial expansion of a syringe which may lead to bursting or to leaks of the pressurized fluid around the seals of the syringe plunger. Another function of a pressure jacket is to prevent forward motion of the syringe. For example, typically a force of 8896 N (2000 pounds) is required to restrain the forward motion of a 200 ml syringe with a cross-section of 1.7 in 2 at 1200 p.s.i. (11 cm 2 at 82 bars) Certain present pressure jackets are one piece designs, where the syringe is inserted into the jacket from the rear end of the jacket. An example of such a pressure jacket is found in U.S. Patent No. 4,677,980, assigned to the common assignee of this application. The neck of the syringe protrudes from the front end of the pressure jacket for connection of fluid lines which lead to the patient. Because the diameter of the syringe neck is much smaller than that of the syringe barrel, it can withstand both radial and forward force. However such an arrangement causes a problem when the syringe is removed from the pressure jacket. The neck of the syringe must pass through the present pressure jacket configurations. This requires the patient fluid path to be disconnected which presents a potential biohazard and may result in spilling fluids onto the pressure jacket. Additionally, fluid spilled during loading and purging air from the syringe may get inside the pressure jacket and require cleaning. Thus, a pressure jacket system is needed which permits a syringe to be front loaded onto an injector head and removed from the injector head without disconnecting the patient fluid path. Further, a pressure jacket system is needed which reduces the materials required for the manufacture of the syringe. US-A-5 078 698 discloses a hypodermic syringe holder adapted to receive a disposable carpule and eject it in an axial direction. The syringe holder includes a pair of pivotable jaws disposed on pivots on opposite sides of the body of the holder and a sleeve element for opening and closing the jaws slidably disposed around the body of the holder. US-A-4 695 271 discloses a fluid injection apparatus comprising a housing with a front opening through which a drive mechanism can reach a plunger or piston inside a syringe and a holding mechanism attached to the housing, the holding mechanism consisting of two parts, namely a pivotable door receiving the syringe and a fixed part supporting the rear end of the syringe. US-A-2 634 889 discloses a dispensing device for calking material having a handle assembly to which a cartridge of calking material may be detachably secured, and a plunger mechanism carried by the handle assembly adapted to advance a piston through the cartridge and force the material therefrom. A pivotable wire system is attached to a hollow cup. DE-C-3 443 435 discloses a dispensing device for putty-cartridges whereby the aspects for possible sterilization are quite different. The cartridge is held in position in a cylindrical housing by a pivoting plate at the front. Yet the plate is not mounted on any rod but pivots in a hollow bearing which only occupies a portion of the front of the cylindrical housing. SUMMARY OF INVENTION The present invention relates to front loadable pressure jacket systems for use with injectors having an injector head with a housing and a front opening. A syringe is connected to the injector front opening to allow the flow of fluids through the syringe. A pressure jacket holds the syringe to the injector head. A piston extendible through the injector front opening imparts motive force to a plunger in the syringe to cause fluid flow. One embodiment of the present invention includes a pressure jacket with a jacket cylinder having an open front end and a rear end coupled to the injector head. A first pivot is coupled to the injector head and a first tie rod is attached to the first pivot. A second pivot is coupled to the injector head and a second tie rod is attached to the second pivot. A front retaining plate joining the front ends of the tie rods allows the retaining plate to be pivotable between a closed position for holding the syringe within the jacket cylinder and an open position to allow the insertion or removal of the syringe from the jacket cylinder. Another embodiment of the present invention includes a pressure jacket with a jacket cylinder having an open front end for receiving the syringe and a rear end coupled to the injector head by a first coupling attachment, at least one arm member having a front end and a rear end coupled to the injector head by a second coupling attachment, and a front retaining plate attached to the front end of the arm member. At least one of the first coupling attachment and the second coupling attachment is a pivot means for permitting relative angular movement between the jacket cylinder and the arm member. In one embodiment the jacket cylinder is transversly pivoted to the front face of the housing to allow the cylinder jacket to be pivoted between a closed position and an opened position. The front retaining plate attached to the front end of the arm member retains the syringe in the jacket cylinder when the jacket cylinder is in a closed position. The jacket permits the loading or removal of the syringe when the jacket cylinder is in an opened position. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of an injector head and front loading syringe that may be used with the embodiments of the present invention; Fig. 2 is a perspective view of a first embodiment of the present invention in an open position; Fig. 3 is a perspective view of the first embodiment of the present invention in a closed position; Fig. 4 is a perspective view of a second embodiment of the present invention in an open position; Fig. 5A is a perspective view of the second embodiment of the present invention in a closed position; Fig. 5B is an isolated view of an alternative to the second embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION Fig. 1 shows an injector head indicated generally at 20 and a syringe 22 which may be used in connection with various embodiments of the present invention. The injector head 20 includes a housing 21 and a front face 23. The injector head 20 is used to actuate syringe 22 which is mounted on the injector head 20. The syringe 22 includes a tubular body 24 and a plunger 26 slidably positioned therein. In operation, the rear of the syringe 22 is fixed in or against an opening 30 on the injector front face 23. Syringe 22 may be affixed to opening 30 by any suitable means, such as mounting flanges (not shown), as described in U.S. Patent No. 5,383,858, assigned to the common assignee of this application and which is fully incorporated herein by reference. Any of the pressure jacket systems which are described below may be used to retain syringe 22 when syringe 22 is affixed to the injector front face 23. The fluid within syringe 22 is pushed forward by a drive means, such as motorized piston 32, extendable and retractable through opening 30, which engages the rear surface 29 of plunger 26 to push plunger 26 forward in the syringe. Figs. 2 and 3 show a first embodiment of the present invention. Fig. 2 shows a fluid injector indicated generally at 210 having a pressure jacket 212 of a swing front retainer type in an open position. Fig. 3 shows the pressure jacket 212 in a closed position. Like the other embodiments previously discussed, the pressure jacket 212 is mounted at its rear end 220 on the injector front face 23 by any suitable means. A syringe 214 inserted into the front end 218 of pressure jacket 212, as shown in Fig. 3, includes a neck 226. The syringe 214 is held in place against force exerted by the injector drive means on the syringe plunger (neither shown) by a front retaining plate 222 which has a slot 224 that allows the neck 226 of the syringe 214 to extend from the cylinder 216 through the front retaining plate 222. The slot 224 is significantly smaller in a direction transverse to the longitudinal axis than the diameter of the syringe 214, so that the remainder of the retaining plate may resist forward-directed force placed on it by the syringe 214 during an injection operation. The slot 224 extends from the center of retaining plate 222 in a direction of the pivot of front plate 222 (discussed below) to the margin of plate 222. In a preferred embodiment, the inside surface of slot 224 is contoured to engage the outside surface of syringe neck 226. For example, if neck 226 is cylindrical in shape, the inside surface of slot 224 is cylindrical. If neck 226 is conical in shape, the inside surface of slot 224 is angled. An adapter 228, which is an annular collar for tie rod connections, is mounted or integrally formed on the injector front face 23 and adjoins the pressure jacket cylinder 216. The collar 228 has a pair of tie rod pins 230 and 232. Bushings 234 and 236 rotate about tie rod pins 230 and 232, forming pivots. Bushings 234 and 236 are connected to and may be integrally formed with to the rear ends of tie rods 238 and 240. The front ends of tie rods 238 and 240 are connected to the front retaining plate 222. It is understood that pins 230 and 232 may be located either on the injector front face 23 or on the exterior of jacket cylinder 216. To open the pressure jacket 212, the tie rods 238 and 240, and front retaining plate 222 are pivoted about the pins 230 and 232 by bushings 234 and 236 which allow the syringe 214 to be inserted into the front end 218 of the jacket cylinder 216. The front plate 222 and the rods 238 and 240 are then pivoted back into place to retain syringe 214. It is understood that an alternative to this embodiment may include a front plate 222 formed by two halves each connected to a rod 238 and 240 such that each halve of the front plate 222 is pivoted into place to retain syringe 214. The advantages relating to the first embodiment, as discussed above, are also realized by this embodiment. Fig. 4 shows a fluid injector indicated generally at 250 having a pressure jacket 252 of a "caulking gun" type. Like the embodiments already described, the pressure jacket 252, when assembled, permits a piston (not shown) housed within an injector head 20 to apply forward force to a plunger (not shown) within a hollow body of a syringe 254, thereby forcing fluid from a front connector end 256 thereof. The pressure jacket 252 has a jacket cylinder 258 which may be made of clear plastic. The jacket cylinder 258 may be rotated about pins 260 and 262 (the last shown in phantom) which are rotatably attached to the front face 264 of the injector head 20. Front face 264 is curved or slanted which allows cylinder 258 to pivot about pins 260 and 262. Cylinder 258 has an open front end 265 by which the syringe 254 may be loaded or removed. Attached to the injector head 20 is the rear end of an elongated arm 266 which is disposed in parallel to the longitudinal axis of syringe 254 when the latter is loaded into pressure jacket 252 and is ready for an injection operation. A retaining wall 268 is orthogonally attached to the front end of arm 266. The retaining wall 268 has an internal surface 270 which is generally spherical or conical in shape so as to mate with an external spherical or conical surface of a syringe transition region 272 located between a syringe cylindrical body 274 and syringe tip 256. Retaining wall 268 has an upwardly open slot 276 for the insertion of the neck 256 of the syringe 254 when the pressure jacket cylinder 258 is moved to a closed position, as shown in Fig. 5A. The slot 276 is cut in the same direction as the direction of articulation of the pivoting pressure jacket 252. As shown in Fig. 4, cylinder 258 of pressure jacket 252 is pivoted to an open position to allow the loading or removal of the syringe 254 into the open end 265 of the cylinder 258. The cylinder 258 is then pivoted back to rest against the arm 266 and the syringe neck 256 is lowered into the slot 276 of the retaining wall 268. The advantages discussed above are also realized by this embodiment. Fig. 5B shows an alternative embodiment to that shown in Fig. 5A. A prong 277 attached to cylinder 258 is provided for engaging slot 276 of retaining wall 268 when the pressure jacket 252 is in the closed position so as to further secure syringe 254 within pressure jacket 252.

Claims: Fluid injection apparatus comprising: an injector head (20) having a housing (21) and a front opening (30) in said housing (21) for connection to a rear end of a syringe (214), drive means (32) extendible through said opening (30) and through an opening in said rear end of the syringe (214) for imparting motive force to a plunger (26) disposed in the syringe (214), and a pressure jacket (212) for holding the syringe (214) to the injector head (20), the pressure jacket (212) including: a jacket cylinder (216) having an open front end (218) and a rear end (220) coupled to the injector head; a first tie rod (238) having a rear end pivotally (230) attached to said injector head and a front end; a second tie rod (240) having a rear end pivotally (232) attached to said injector head and a front end; a front retaining plate (222) joined to said front ends of said first and second tie rods (238, 240), said retaining plate (222) and said tie rods (238, 240) being pivotable between a closed position for holding the syringe (214) within said jacket cylinder (216) and an open position to allow the insertion and removal of the syringe (214) from said jacket cylinder (216). The fluid injection apparatus of Claim 1 wherein the front retaining plate is formed of two halves, each half connected to its respective tie rod (238, 240) for pivoting between the closed and open positions. The apparatus of claim 1 or 2 wherein the cylinder jacket (216) is substantially clear plastic. The injection apparatus of any one of claims 1 to 3 wherein said jacket cylinder (216) is formed around a longitudinal axis, said front retaining plate (222) having an opening (224) formed therein to permit a syringe neck (226) of reduced diameter to protrude therethrough, when said plate (222) and said tie rods (238, 240) are in said closed position, said front retaining plate opening (224) being smaller in a direction transverse to said axis than a diameter of a body portion of the syringe (214). The injection apparatus of Claim 4, wherein said opening of said front retaining plate (222) is a slot (224) formed from a lateral margin of said plate (222) through a center thereof, said slot (224) formed in the direction of pivot of said retaining plate (222) and tie rods (238, 240). The injection apparatus of any one of claims 1 to 5 wherein said rear ends of said tie rods (238, 240) are pivotally affixed to an upstanding annular collar (228) of said injector head (20). Fluid injection apparatus comprising: an injector head (20) having a housing (21) and a front opening (30) in said housing (21) for connection to a rear end of a syringe (254), drive means (32) extendible through said opening (30) and through an opening in said rear end of the syringe (254) for imparting motive force to a plunger (26) disposed in the syringe (254), and a pressure jacket (252) for holding the syringe (254) to the injector head (20), the pressure jacket (252) including: a jacket cylinder (258) having an open front end (265) for receiving the syringe (254) and a rear end coupled to the injector head (20) by a first coupling attachment (260, 262); at least one arm member (266) having a front end and a rear end coupled to the injector head (20) by a second coupling attachment; and a front retaining plate (268) attached to the front end of the arm member (266), wherein at least one of the first coupling attachment and the second coupling attachment is a pivot means for permitting relative angular movement between the jacket cylinder (258) and the arm member (266).

Inventors: GELBLUM EUGENE A, HIRSCHMAN ALAN D, REILLY DAVID M, UBER ARTHUR E, GELBLUM, EUGENE A., HIRSCHMAN, ALAN D., REILLY, DAVID M., UBER, ARTHUR E.
Applicants: MEDRAD INC, MEDRAD, INC.
Application year: 1996
Main classification: A61M5
IPC codes: A61M5, B05C17, A61M37