This .Iadd.application is a continuation of Ser. No. 07/316,868 filed Jul. 7, 1989, abandoned, which .Iaddend.is a continuation-in-part of application Ser. No. 617,807, filed June 6, 1984, and now abandoned.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relies to the field of angiography. Angiography is the study of blood vessels with the use of x-rays while injecting an iodine-based or other fluid (contrast media) into the body through a catheter situated in a blood vessel. An angiographic injector utilizes an angiographic syringe filled with contrast media and serves to control the delivery rate, amount, pressure. etc., of the fluid being injected.
2. Background of the Prior Art
Although there are many angiographic injectors (see U.S. Pat. Nos. 4,006,736, for example) and many angiographic syringes commercially available in the world market, there are certain areas where improvements or advances can be made. For example, there is no known multiple-syringe angiographic injector permitting the syringe plunger to be disengaged without retracting the plunger back through the syringe and hence possibly drawing blood and other fluid from the patient. Also, the design of the prior art syringe may not maximize the purging of air from within because of the taper angle of the syringe's end. Finally, the length of the discharge extension in prior art syringes does not permit efficient handling of the syringe by the surgeon.
Accordingly, it is an object of this invention to provide an angiographic injector which utilizes a means for engaging an angiographic syringe which is capable of unilaterally disengaging and retracting from the syringe plunger without drawing the plunger back through the syringe.
Another object of the invention is to provide an angiographic syringe fixedly mountable within the pressure jacket to maintain alignment between the syringe and the pressure jacket
Yet another object of this invention is to provide an angiographic syringe which promotes improved air removal therefrom.
Still another object of this invention is to provide an angiographic syringe which increases the size of the sterile work field.
SUMMARY OF THE INVENTIONIn general, an angiographic syringe includes a plunger which is advanceable through a tubular body for forcing contrast media from a discharge end of the tubular body into the vascular system of an animal in an injection operation. The plunger is advanced through the tubular body by an actuating mechanism of an angiographic injector. After the injection operation has been completed, the actuating mechanism is retractable relative to the plunger of the syringe without causing any substantial retraction of the plunger in the tubular body so as to draw body fluid of the animal into the syringe.
More specifically, the foregoing and other objects of the invention are achieved by providing a novel angiographic injector utilizing a specially adapted novel angiographic syringe. The angiographic injector has an injector portion which includes a rotating turret for housing multiple syringes in readiness for injection. The injector further employs a driving mechanism for connecting with and controlling the movement of the syringe plunger once the syringe is in place for injection. Through the use of guide means on the syringe and corresponding alignment means on the pressure jacket, the syringe is alignably and securely mounted within the pressure jacket on the rotating turret. In certain arrangements, the syringe plunger is positioned within the syringe such that when the syringe is mounted within the pressure jacket, a plunger connecting means will be properly aligned for mating with the driving mechanism. This mating occurs upon rotation of the turret into position for injection on the injector portion. Once the injection is complete, the driving mechanism may be disengaged from the plunger connecting means by rotating the driving mechanism or the syringe plunger, thereby freeing the driving mechanism from the plunger so the driving mechanism can be retracted from the syringe. In other arrangements, prealignment of the plunger and the drive mechanism, and/or rotation of either the syringe plunger or the drive mechanism to release the driving mechanism from the plunger are not necessary. A discharge extension of the angiographic syringe also has been lengthened and an intermediate portion of the syringe has been given a less severe taper.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a perspective view of an angiographic injector of the present invention, illustrating an injector portion and turret assembly;
FIG. 2 is a cross-sectional view of a syringe of the present invention;
FIG. 3 is a sectional plan view of a tapered neck portion of the syringe of FIG. 2;
FIG. 4 is a transverse cross-sectional view taken alongline 4--4 of FIG. 2:
FIG. 5 is a side view of a pressure jacket and syringe assembly of the present invention;
FIG. 6 is a front view of the pressure jacket of FIG. 5;
FIG. 7 is a view of the injector of FIG. 1 wherein the turret is rotated out of operative position to expose the plunger-engaging driving mechanism of the injector portion;
FIG. 8 is an end view of the syringe of FIG. 2;
FIG. 9 is a side view of the syringe and driving mechanism as mated and prepared for injection;
FIG. 10 is a view similar to that of FIG. 9, showing the syringe and driving mechanism in a plunger-release position as a result of rotation of the driving mechanism;
FIG. 11 is a plan view of an alternate form of rotatable-type plunger release mechanism of the present invention, in a released position, with a part of the mechanism as shown in cross-section, as viewed along the line 11--11 in FIG. 12;
FIG. 12 is a view of part of the plunger release mechanism of FIG. 11 as viewed in the direction of thearrows 12--12 in FIG. 11;
FIG. 13 is a developed pattern view of an internal cam arrangement formed in the part of the plunger release mechanism shown in FIG. 12;
FIG. 14 is a partial developed pattern view of another form of internal cam arrangement which may be utilized in the plunger release mechanism shown in FIGS. 11, 12, and 13;
FIG. 15 is a partial view or a portion of the apparatus of the present invention, demonstrating another form of plunger release mechanism which may be utilized with the internal cam arrangement shown in FIG. 14;
FIG. 16 is a cross-sectional side view of a reciprocable-type plunger release mechanism of the present invention;
FIG. 17 is a plan view of another rotatable-type plunger release mechanism of the present invention, in a released position;
FIG. 18 is a partial view taken along theline 18--18 of FIG. 17;
FIG. 19 is a partial view illustrating the plunger release mechanism shown in FIG. 17, in a locked position as viewed along a line designated 19--19 in FIG. 17;
FIG. 20 is a plan view, partially in cross-section, of a first electromagnetic-type plunger release mechanism of the present invention; and
FIG. 21 is a plan view, partially in cross-section, of a second electromagnetic-type plunger release mechanism of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTReferring now to FIGS. 1 and 2, the angiographic injector of the present invention is shown generally at 10. Theinjector 10 comprises aninjector head portion 12 and a control unit (not shown),injector head portion 12 further comprising aturret 14 rotatably mounted about ashaft 61.Shaft 61 includes an aperture (not shown) which aligns with aperture 62a inturret 14 whenturret 14 is in position for injection.Pin 62 passes through the apertures, thereby holdingturret 14 in its proper position. Twopressure jackets 16 and 16a are fixed inturret 14 and houserespective syringe cartridges 18 and 18a.
Thesyringe 18 comprises an elongatedtubular body 22 and acoaxial discharge extension 20, connected by anintermediate portion 24. Thetubular body 22 has a circular, outwardly extendingflange 32 on one end, as well as a plunger 38-1 slideably positioned within thetubular body 22.Flange 32 serves as an abutment face for associating with the rear portion ofpressure jacket 16. Plunger 38-1 comprises abase member 38a, and two hook orlug members 38b extending therefrom; the plunger 38-1 serving to control the ejection of fluid contained withinsyringe 18 in a desired quantity and at a desired rate.Hook members 38b are designed to facilitate axial movement of plunger 38-1.
Intermediate portion 24 ofsyringe 18 is in the shape of a funnel and comprises two sections, ahollow cone 24a and atapered neck 24b. On the surface of the taperedneck 24b are located one or more guide extension tabs, three being illustrated at 26, 28 and 30. Extending axially from the taperedneck 24b isdischarge extension 20 which includes a nozzle 20a, and terminates indischarge outlet 36.Discharge extension 20 serves as a guide means and provides an attachment point forconnector 42 which engages with a catheter (not shown). The configuration of the nozzle 20 a ofdischarge extension 20 corresponds with generally accepted taper lengths and angles as described in ASA Standard Z-1955 so as to be matcable with conventional catheters.Inner passageway 34 withinextension 20 can be generally cylindrical, and provides communication betweendischarge outlet 36 and the interior oftubular body 22.
In an effort to improve the air removal capability ofsyringe 18,hollow cone 24a has a taper angle ranging between 40° and 50°, as compared to the 30° angle of conventional prior art syringes. In the illustrated embodiment,cone 24a has a 45° taper angle so as to compromise between maximum air removal and manufacturing ease. Similarly, plunger 38-1 has a taper angle corresponding to that ofhollow cone 24a. In addition, the combined length oftapered neck 24b anddischarge extension 20 ranges between 27/8 inches and 31/2 inches, thereby providing the physician with a larger sterile work field. In the prcrerred embodiment, this combined length is set at 31/4 inches so as to compromise between maximum strength and length oftapered neck 24b anddischarge extension 20, and manufacturing case.
FIGS. 3 and 4 illustrate more clearly the features and disposition ofguide extensions 26, 28 and 30. In essence, guideextensions 26, 28 and 30 are raised portions ofsyringe 18 which extend from the end ofhollow cone 24a to approximately the middle oftapered neck 24b. Although preferably made of the same material assyringe 18 and integrally formed therewith, guideextensions 26, 28 and 30 may be made of other types of plastic or suitable materials,syringe 18 preferably being formed from a relatively rigid, translucent plastic material. While the preferred embodiment employs threeguide extensions 26, 28 and 30, more or less may be used. Also, the extensions may be identical, or they may be of different dimensions. For example, as shown,side guide extension 28 is larger in width but smaller in height than eithertop guide extension 26 orbottom guide extension 30. It also should be noted that located on theflange 32 oftubular body 22 is analignment edge 40 which is in line withguide extension 28.
Alignment edge 40 is used to facilitate assemblage ofsyringe 18 withpressure jacket 16, as shown in FIGS. 5 and 6. Typically,syringe 18 is used together withpressure jacket 16 as a single, functional unit used in conjunction with an angiographic injector. In particular,pressure jackets 16 and 16a are securely and alignably mounted within theturret 14 so as to provide a means for mountingsyringes 18 and 18a onturret 14 for injection.Pressure jacket 16 has ahollow body portion 51, which is substantially the same length astubular body 22 ofsyringe 18, and aconical nose section 52, which is designed to fit over thehollow cone section 24a ofsyringe 18. At the end ofconical nose section 52 isend face 54 which has guide extension notches orslots 46, 48 and 50 formed therein.Guide extension notches 46, 48 and 50 correspond to and are substantially of the same dimensions asguide extensions 26, 28 and 30, respectively. While the preferred embodiment employs threeguide extension notches 46, 48 and 50, more or less may be used.
Located on the opposite end ofpressure jacket 16 is analignment indicator 44 which corresponds toalignment edge 40 ofsyringe 18.Alignment indicator 44 is used to ensure proper alignment ofguide extensions 26, 28 and 30 withguide extension notches 46, 48 and 50 assyringe 18 is placed intopressure jacket 16. Once withinpressure jacket 16, thetubular body 22 andhollow cone 24a portions ofsyringe 18 are completely enveloped bypressure jacket 16, whiletapered neck 24b anddischarge extension 20 protrude through theend face opening 56 so as to facilitate connection with a catheter. Being arranged in this manner, guideextensions 26, 28 and 30 preventsyringe 18 from rotating withinpressure jacket 16 and serve to alignsyringe 18 with bothpressure jacket 16 andturret 14.
Referring now to FIGS. 1 and 7, the two-syringe turret mechanism will be described in further detail.Turret 14, which housespressure jackets 16 and 16a andsyringes 18 and 18a is equipped with two projectingstops 58a and 58b. Fixed to theinjector portion 12 areabutment members 60a and 60b adapted to associate with thestops 58a and 58b, respectively. The association between thestops 58a and 58b and theabutment members 60a and 60b limits the rotation ofturret 14 from the position illustrated in FIG. 1 to the position which would be achieved by rotatingturret 14 in the direction of arrow T. Therefore, once syringe 18a is in position for injection as shown in FIG. 1,turret 14 can only turn in the direction of arrow T until stop 58a associates withabutment member 60a, thereby ending rotational movement ofturret 14 and aligningsyringe 18 for injection.
FIG. 7 illustrates the positions ofturret 14 achievable upon partial rotation in the direction of arrow T from the position shown in FIG. 1. In this intermediate position, a driving mechanism, shown generally at 66-1 in its fully retracted position, is exposed. Driving mechanism 66-1 includes abase portion 68, astem 69 and arectangular head 70 extending from thebase portion 68 and integrally formed therewith. In this embodiment, as seen best in FIG. 9,plunger hook members 38b are L-shaped and are disposed so as to define anaperture 39 therebetween and anaccess slot 39a communicating with theaperture 39. Thisaperture 39 andaccess slot 39a are designed to mate with thehead 70 and stem 69 of driving mechanism 66-1, such thathead 70 fits within theaperture 39 and stem 69 extends through theaccess slot 39a.Ram elements 64a and 64b are integral with and extend from the main surface of the driving mechanism. This piston and ram arrangement is motor driven by a mechanism mounted ininjector head 12, and has the same physical and operational characteristics as its counterpart disclosed in U.S. Pat. No. 4,006,736. Therefore, its configuration and operation will not be discussed in detail.
In operation, and referring now to FIGS. 1 and 7-10,syringes 18 and 18a are secured inpressure jackets 16 and 16a, respectively, by aligningsyringe alignment edge 40 with pressurejacket alignment indicator 44 upon insertion ofsyringes 18 and 18a. By effecting such alignment, guideextensions 26, 28 and 30 pass throughnotches 46, 48 and 50, respectively, thereby holdingsyringes 18 and 18a in alignment withinpressure jackets 16 and 16a.
The proper alignment ofsyringes 18 and 18a andpressure jackets 16 and 16a is of critical importance because of the operational characteristics of the driving mechanism 66-1. Specifically, syringeplunger hook members 38b must be in proper position to mate with thehead 70 of driving mechanism 66-1.
FIG. 8 is a rear view of thesyringe 18 illustrating the proper alignment of the plunger 38-1 therein. During manufacture ofsyringe 18, plunger 38-1 is disposed withinsyringe 18 such thathook members 38b extend in a predetermined relationship with thealignment edge 40 and hence withguide extensions 26, 28 and 30. As illustrated,hook members 38b extend inwardly toward the center of plunger 38-1 and are perpendicular toalignment edge 40. Therefore,pressure jacket 16 must be mounted onturret 14 so as to permit alignment ofhead 70 andhook members 38b. In the illustrated embodiment, this alignment is achieved by mountingpressure jacket 16 onturret 14 such thatalignment indicator 44 is in a horizontal disposition whenturret 14 is the position shown in FIG. 1.
Once thepressure jackets 16 and 16a are in place onturret 14, andsyringes 18 and 18a secured therein,turret 14 is rotated in the direction of arrow T, as shown in FIG. 7, until projecting stop 58a engages correspondingabutment member 60a. plunger 38-1 is disposed at the end ofsyringe 18 withhook members 38b protruding therefrom such thathook members 38b mate or releasably interlock withhead 70 of the driving mechanism 66-1 upon rotation of theturret 14, such that the hook members and the head form respective parts of a quick release driving connection between the plunger and the driving mechanism. In particular,head 70 fits into theaperture 39 formed byhook members 38b, withstem 69 extending out from theaperture 39 throughaccess slot 39a. FIG. 9 illustrates the configuration of driving mechanism 66-1 and plunger 38-1 upon mating, focusing only on the connection between the two. As this figure illustrates, the dimensions ofhook members 38b, as well ashead 70 and stem 69 are critical to a proper fit. Once in the position illustrated in FIG. 9, injection may proceed through the actuation of driving mechanism 66-1, as discussed in U.S. Pat. No. 4,006,736. In particular, driving mechanism 66-1 may be moved forward, thus driving plunger 38-1 throughsyringe 18 and expelling air therefrom. Aftersyringe 18 is connected to a source of contrast media, driving mechanism 66-1 may be retracted fromsyringe 18, thus pulling plunger 38-1 back throughsyringe 18 so as to draw contrast media intosyringe 18. Once filled,syringe 18 is ready for injection.
After the injection has been carried out, driving mechanism 66-1 may be disengaged from plunger 38 as shown in FIGS. 9 and 10. Without reversing its movement, driving mechanism 66-1, shown in FIG. 9, is rotated 90° in the direction of arrow R. This rotational movement results in the configuration shown in FIG. 10, whereinhead 70 extends fromaperture 39 on either side. As shown in FIG. 10, the depth d ofhead 70 must be smaller than the width of theaccess slot 39a so as to allow removal therefrom. Disengagement is then effected by retracting driving mechanism 66-1 in the direction of arrow D so thathead 70 passes throughaccess slot 39a. Because no reverse pressure is applied to plunger 38-1, the risks attendant to drawing the plunger 38-1 back through thesyringe 18 are eliminated. Thus, themating hook members 38b andhead 70 cooperate so that the plunger 38-1 can be placed in a driven retractable state or an undriven nonretractable state of any time during the injection operation and at any position of the plunger, without substantial force being applied therebetween.
FIG. 11 discloses an alternate form of plunger release mechanism 80-2 of a rotatable type in which prealignment of a plunger 38-2 and a drive mechanism 66-2 are not required to connect the plunger to the drive mechanism, or to release the plunger from the drive mechanism. In this embodiment of the invention, the plunger 38-2 includes a projectingcylindrical hub 88 having a pair of laterally projecting drive lugs 90. Further, the drive mechanism 66-2 is rotatably mounted for free rotation on one end of adrive piston 98.
The drive mechanism 66-2 comprises acamming assembly 91 made up of fourcamming segments 92, with each segment defining a quadrant of the cylindrical camming assembly. Thecamming segments 92 are held together by a clampingring 94 force-fitted and/or bonded about the periphery of thecylindrical camming assembly 91. Thecylindrical camming assembly 91 is rotatably mounted for its free rotation on thedrive piston 98, on astub shaft 96 projecting from the piston, and is held on the stub shaft by a suitable C-shapedretaining clip 100. Thecylindrical camming assembly 91 also includes an internalcylindrical aperture 102 for receiving thehub 88 of the plunger 38-2. The forming of thecylindrical camming assembly 91 from a plurality of parts, such as thequadrant camming segments 92, facilities molding and/or machining of an internal camming arrangement of the assembly, as shown in FIG. 13.
Referring to FIG. 13, a camming pattern formed on the internal side of each of thequadrant camming segments 92 includes a plurality of entry-exit openings 104 arranged about the internal periphery of thecylindrical camming assembly 91. The entry-exit openings 104 are defined by inclined camming surfaces 106 of a series ofcamming members 108. In operation, as thedrive piston 98 advances the drive mechanism 66-2 toward the plunger 38-2, each of the drive lugs 90 on thehub 88 of the plunger is received in a respective one of the entry-exit openings 104 as illustrated in FIG. 13. Eachdrive lug 90 is then guided by one or the other of the adjacent camming surfaces 106 into aninternal passageway 110, with the drive mechanism 66-2 rotating in one direction or the other for this purpose. Each of the drive lugs 90 then engages one of a plurality of cam surfaces 112 of arear wall 113 of an essentially saw-tooth configuration, and is guided by this cam surface into apocket 114 of the rear wall. Continued movement of thedrive piston 98 and the drive mechanism 66-2 then causes advancement of the plunger 38-2 through an associated syringe (not shown).
When the drive mechanism 66-2 then is retracted by thedrive piston 98, each of the drive lugs 90 engages anotherinternal camming surface 116 on theadjacent cam member 108 and is guided by the cam surface into apocket 118 in the cam member. The retracting drive mechanism 66-2 then also retracts the plunger 38-2 therewith through the associated syringe to fill the syringe with a contrast media for an injection operation.
As the drive mechanism 66-2 then is again advanced by thedrive piston 98, each of the drive lugs 90 engages another one of the internal camming surfaces 112 of therear wall 113, and is guided by this camming surface into another of theinternal pockets 114 in therear wall 113. Now, continued advancement of the drive mechanism 66-2 moves the plunger 38-2 through the associated syringe to inject the contrast media from the syringe in a normal manner.
After the injection operation has been completed, the drive mechanism 66-2 is again retracted by thedrive piston 98. Each of the drive lugs 90 now engages aninternal camming surface 124 on theadjacent cam member 108 and is guided by this cam surface through an adjacent second one of theinternal passageways 110 and out of thecylindrical camming assembly 91 through a second one of the entry-exit openings 104, to disengage the plunger 38-2 from the drive mechanism 66-2. Thus, the drive mechanism 66-2 then can be retracted without withdrawing the plunger through the associated syringe so as to draw body fluids from the patient into the syringe, as discussed hereinabove relative to the apparatus shown in FIGS. 1-10. During the above operation of the drive mechanism 66-2, the freely rotatable drive mechanism rotates relative to the plunger 38-2 as necessary in order to enable movement of the drive lugs 90 of the plunger through the drive mechanism.
FIG. 14 discloses a partial pattern of an alternate internal camming arrangement of a drive mechanism 66-2', which may be used in place of the internal camming arrangement of the drive mechanism 66-2 shown in FIGS. 11-13. In the internal camming arrangement shown in FIG. 14, as the drive mechanism 66-2' is advanced relative to the plunger 38-2 (FIG. 11), each of the pair of laterally projecting drive lugs 90 (only one shown) on thecylindrical hub 88 of the plunger is guided by cam surfaces 106' of adjacent camming portions 108' through apassageway 110' into an internal pocket 114' formed in a rear wall portion 113' of an associated quadrant camming segment 92'. The drive mechanism 66-2' then advances the plunger through the associated syringe (not shown) as above described.
When the drive mechanism 66-2' then is retracted, each of the plunger drive lugs 90 engages in an internal pocket 118' of the adjacent camming portion 108', to retract the plunger through the syringe and to fill the syringe with contrast media as above described. Subsequently, when the drive mechanism 66-2' is again advanced for an injection operation, each of the plunger drive lugs 90 reseats in the respective internal pocket 114' and the plunger is advanced through the syringe for an injection operation. Then, when the injection operation is completed, as the drive mechanism 66-2' is again retracted by an associated drive piston (not shown), the drive piston, and thus the drive mechanism through inherent friction, also may be rotated slightly such that each of the plunger drive lugs 90 disengages from the drive mechanism through thesame passageway 110' through which the drive lug became engaged with the drive mechanism.
FIG. 15 discloses an arrangement in which, rather than rotate the drive mechanism 66-2' in FIG. 14 as the drive mechanism is retracted, in order to disengage the plunger drive lugs 90 from the drive mechanism, the plunger 38-2 is rotated relative to the drive mechanism. In this connection, the embodiment of the invention shown in FIG. 15, which is a back view of a portion of a modified turret 14', includes a modified pressure jacket 16' which receives thesyringe 18 shown in the embodiment of the invention shown in FIGS. 1-10. Further, thesyringe 18 receives the plunger 38-2 as shown in the embodiment of the invention of FIGS. 11-13.
More specifically, the pressure jacket 16' is mounted on the modified turret 14' from the back thereof and is retained on the turret by a pair ofmachine screws 124 mounted on the back of the turret. The pressure jacket 16' is retained against rotation in the turret 14' by adetent member 126 pivotally mounted in a recess in the back of the turret and including a resilientintegral biasing spring 128.
To mount the pressure jacket 16' on the turret 14',notches 130, formed in aperipheral flange 132 of the pressure jacket, arr aligned with themachine screws 124, and anotch 133 in the peripheral flange is aligned with a detenting portion 126a of thedetent member 126. Theperipheral flange 132 of the pressure jacket 16' is then engaged against the turret 14' and the jacket is rotated slightly counterclockwise, as viewed in FIG. 15, so that themachine screws 124 are received inseats 134 formed in the flange, and so that thespring detent member 126 rides into asmall retaining notch 136 in the flange.
When it is desired to release the plunger 38-2 from the drive mechanism 66-2' in FIG. 14 utilizing the arrangement of FIG. 15, the pressure jacket 16' is manually rotated clockwise, as viewed in FIG. 15, so that themachine screws 124 travel inrespective grooves 138 formed in theperipheral flange 132 of the pressure jacket 16'. As a result, thesyringe 18 in the pressure jacket 16', being in fixed relationship thereto as described herein above in the embodiment of the invention shown in FIGS. 1-10, also rotates with the jacket. Similarly, the plunger 38-2, as a result of inherent friction between the plunger and thesyringe 18, is rotated with the syringe to disengage the plunger drive lugs 90 from the drive mechanism 66-2' as the drive mechanism is retracted at the conclusion of an injection operation.
FIG. 16 discloses a plunger release mechanism 80-3, which is of a reciprocable-type and does not require rotation of an associated plunger 38-3 or drive mechanism 66-3. The plunger release mechanism 80-3 includes asmall latching device 140 of a type as disclosed in U.S. Pat. No. 2,637,576, the disclosure of which, to the extent not inconsistent with this disclosure, is hereby incorporated by reference. Thelatching device 140 is substantially enclosed in a box-shapedhousing 141 suitably mounted on acylindrical hub 142 of thepiston rod 98. Thelatching device 140 includes apivotable latch member 143 having integral dependingside flanges 144 provided with upper and lower sets ofnotches 145 and 146 for receiving respective upper and lower pivot pins 147 and 148 mounted in side-walls (only one shown) of thehousing 141. Acoil spring 149 is connected at one end to a tab on thelatch member 143 and at an opposite end to atang 150a of aslide member 150 mounted on a housing bottom wall. Abumper coil spring 151 also is supported on theslide tang 150a and theslide 150 includes a pair of upwardly inclined stop lugs 150b. The plunger 38-3 includes alatch member 152 rigidly mounted thereon.
In operation, as thedrive piston 98 advances, therigid latch member 152 on the plunger 38-3 is received into an open end of the latchingdevice housing 141, to cause theslide member 150 to move relative to the housing, to the left in FIG. 16. When ahook portion 152a on therigid latch member 152 clears a dependinghook portion 143a on thepivotable latch member 143, as illustrated by broken lines in FIG. 16, the latter latch member is pulled downward by thespring 149 about theupper pivot pin 147, into thehook portion 152a. At substantially the same time, aflange 155 of thelatch member 152 is engaged by the adjacent end of thehousing 141 to cause movement of the plunger 38-3 through an associated syringe (not shown).
As thedrive piston 98 then retracts thelatching device 140, the latchmember hook portions 143a and 152a interengage so that the plunger 38-3 is retracted through the syringe to fill the syringe with contrast media in a normal manner. The retracting operation also causes thepivotable latch member 143 to be shifted slightly to the right in FIG. 16 into position for subsequent pivoting about thelower pivot pin 148.
Subsequently, when thedrive piston 98 again advances thelatching device 140 in an injection operation, the pivotable latchmember hook portion 143a is released from the rigid latchmember hook portion 152a so that thecoil spring 149 now pivots thepivotable latch member 143 upward about thelower pivot pin 148, thereby returning the pivotable latch member to its inoperative position. Accordingly, when thelatching device 140 is retracted by thedrive piston 98 at the conclusion of the injection operation, therigid latch member 152 releases from thelatching device 140, leaving the plunger 38-3 is an advanced position in the syringe.
FIG. 17 discloses another rotatable-type plunger release mechanism 80-4 which includes a plunger 38-4 and a drive mechanism 66-4. The plunger 38-4 includes arotatable member 156 mounted for free rotation on a projectingstem 158. Therotatable member 156 includes a series of raised screw-type threads 160 which define a plurality ofinclined channels 162 therebetween. Therotatable member 156 is retained on thestem 158 in a suitable manner, such as by a C-shapedclip 164.
The drive mechanism 66-4 includes a pair ofopposed hook assemblies 166 fixedly mounted at inner ends thereof on thedrive piston 98. Each of thehook assemblies 166 includes aright angle member 168 having ahook member 170 fixedly mounted thereon adjacent an outer end thereof, with the hook member being of an essentially inverted V-shaped configuration, as viewed in FIGS. 18 and 19.
In use, as the drive mechanism 66-4 is initially advanced by thedrive piston 98, the hook shapedmembers 170 enter respective ones of thechannels 162 between thescrew threads 160, with therotatable member 156 rotating to permit passage of the hook members through the channels. Eventually, outer ends of thehook assemblies 166 engage the plunger 38-4 to move the plunger through an associated syringe (not shown) in the usual manner. In the alternative, by proper dimensioning, thedrive piston 98 can engage an adjacent end of theplunger stem 158 to cause this movement.
When thedrive piston 98 then is retracted to retract the drive mechanism 66-4, the outer end portions of thehook members 170 engage over adjacent ones of thescrew threads 160 as shown in FIG. 19, such that the plunger 38-4 then is retracted with the drive piston to fill the associate syringe with contrast media. When thedrive piston 98 is then advanced in an injection operation, the plunger 38-4 again is advanced as above described. Subsequently, before thedrive piston 98 is retracted at the conclusion of the injection operation, the drive piston and thehook assemblies 166 thereon may be rotated slightly to align the outer end portions of thehook members 170 with the adjacentrespective channels 162, such that when the drive piston is retracted the hook members move back through the channels to disengage from therotatable member 156 on the plunger 38-4. In the alternative, the plunger 38-4 may be mounted in a rotatable pressure jacket as disclosed by the pressure jacket 16' in FIG. 15 and the plunger 38-4 may be rotated by rotation of the pressure jacket to cause the desired disengagement.
FIG. 20 discloses a plunger release mechanism 80-5 of an electromagnetic-type, which comprises a plunger 38-5 and a drive mechanism 66-5. The plunger 38-5 includes a projecting stem 172 having anannular flange 174 fixedly mounted thereon.
The drive mechanism 66-5 includes anelectromagnet 176 which comprises aferromagnetic core 178 and acoil 180 surrounding the core. The drive mechanism 66-5 further includes a pair ofopposed latch members 182 of ferromagnetic material pivotally mounted adjacent inner ends thereof on themagnetic core 178 of theelectromagnet 176. Thelatch members 182 includeouter latch portions 184 for engaging around theannular flange 174 of the plunger 38-5. Theouter latch portions 184 include tapered camming surfaces 184c and are dimensioned so as to substantially fill the space between theannular flange 174 and the plunger 38-5, so that lost motion between thelatch members 182 and the plunger is essentially eliminated. Thelatch members 182 are biased toward one another into a closed position by an interconnectingcoil spring 186. Theelectromagnet 176 is mounted within a substantiallyU-shaped pole piece 188 of ferromagnetic material, having a base 190 fixed to thedrive piston 98 and having a pair of projectingside legs 192.
In use, theelectromagnet 176 of the drive mechanism 66-5 may be energized in preparation for an injection operation, so that theferromagnetic latch members 182 are attracted toward theside legs 192 of theferromagnetic pole piece 188 into open broken line positions as indicated in FIG. 20. The drive mechanism 66-5 then is advanced by thedrive piston 98 until thehook portions 184 of the latch members have advanced past theannular flange 174 on the plunger 38-5, whereupon theelectromagnet 176 is deenergized. Thelatch members 182 are then returned by thecoil spring 186 to their closed position on opposite sides of theplunger flange 174 as illustrated in solid lines in FIG. 20. In the alternative, theelectromagnet 176 may be left deenergized and thelatch members 182 may be cammed outward by engagement of the camming surfaces 184c with theannular flange 174 as the drive mechanism 66-5 is advanced. In either instance, continued advancement of the drive mechanism 66-5 then causes thehook portions 184 of thelatch members 182 to engage the plunger 38-5, to advance the plunger through an associated syringe.
Subsequently, when the drive mechanism 66-5 is retracted by thedrive piston 98, thehook portions 184 on thelatch members 182 engage rear portions of the plungerannular flange 174 to cause retraction of the plunger 38-5 in the syringe, to fill the syringe with a contrast media. As the drive mechanism 66-5 is then advanced by thedrive piston 98 in an injection operation, the latchmember hook portions 184 again engage the plunger 38-5 to advance the plunger through the syringe. At the end of the injection operation, theelectromagnet 176 is again energized, causing thelatch members 182 to be attracted to theside legs 192 of theferromagnetic pole piece 188, thus releasing the plunger 38-5 from the drive mechanism 66-5. The drive mechanism 66-5 then may be retracted from the syringe relative to the plunger 38-5 by thedrive piston 98.
Referring to FIG. 21, there is disclosed a second electromagnetic form of a plunger release mechanism 80-6 in which no rotation or prealignment of a plunger 38-6 and a drive mechanism 66-6 is required. In this connection, the plunger 38-6 includes a ferromagnetic member ormaterial 194, which may include iron filings or be a permanent magnet, suitably mounted in a rear portion of the plunger. The drive mechanism 66-6 includes an electro-magnet 196 suitably mounted on thedrive piston 98. Theelectromagnet 196 includes aferromagnetic core 198 and acoil 200 disposed in anannular housing 202 of ferromagnetic material.
In use, as the drive mechanism 66-6 is advanced by thedrive piston 98, theelectromagnet 196 engages the plunger 38-6 to initially advance the plunger through an associated syringe. With theelectromagnet 196 energized so as to attract the ferromagnetic member orpermanent magnet 194 of the plunger 38-6 to theferromagnetic core 198 andhousing 202 of the electromagnet, when the drive mechanism 66-6 then is retracted by thedrive piston 98, the plunger is also retracted with the drive mechanism to fill the syringe with a contrast media. When the drive mechanism 66-6 then is again advanced, theelectromagnet 196 pushes the plunger 38-6 through the associated syringe for an injection operation. Theelectromagnet 196 is then deenergized or reversed in polarity, to release the ferromagentic member orpermanent magnet 194, respectively, therefrom, whereupon the drive mechanism 66-6 can be retracted from the syringe by thedrive piston 98 relative to the plunger.
Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifictions can be made without departing from the spirit and scope of the present invention. For example, the relative positions of the parts of the plunger release mechanisms on the plungers 38 and the drive mechanisms 66, such as thehook members 38b on the plunger 38-1, and thestem 69 andhead 70 of the driving mechanism 66-1, in FIGS. 1-10, can be reversed, with the stem and head mounted on the plunger and the hook members mounted on the drive mechanism. Further, with reference to FIGS. 11-13, the camming arrangement of the drive mechanism 66-2 may be formed on external sides of thequadrant camming segments 92, with thelugs 90 on the plunger 38-2 extending rearwardly (downwardly in FIG. 11) and having laterally projecting portions extending radially inward, in a manner similar to the configuration of thehook members 38b in FIG. 2. It therefore is the intent to encompass within the appended claims all such changes and modifications that fall within the scope of the present invention.