Patent Publication Number: US-9895487-B2

Title: Compact non-electric medicament infuser

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from International Patent Application No. PCT/US2012/000550 filed on Nov. 8, 2012. 
     FIELD OF THE INVENTION 
     The following invention relates to infusion equipment for delivering medicament (medication or other medical preparations) into the bloodstream or other locations within the body of a patient or animal. More particularly, this invention relates to infusion devices which work with a standard medical syringe to deliver medicament from the syringe over a desired period of time and in a manner which does not require electronics or coupling to an external power source for proper function. 
     BACKGROUND OF THE INVENTION 
     Many medicaments require infusion into a patient or animal over an extended period of time, rather than in a single immediate dose. Infusion systems are known in the art to allow such medicaments to be so infused in a controlled fashion over a period of time. Such infusion systems generally include an intravenous access point where a medical professional has already placed an “IV” into the patient with medical tubing coupled to a needle penetrating the skin and typically into a vein of the patient. Additionally, such infusion systems include some form of reservoir for containing the medicament to be delivered and some form of infusion device for causing the medicament to move along the infusion tubing and through the IV into the patient. 
     In perhaps a simplest infusion system, gravity provides the force required by merely placing the reservoir at a height elevated relative to the IV intravenous access point. Gravity fed infusion systems have limitations in that the amount of force cannot be readily changed, other than through the imprecise method of increasing the elevation of the supply reservoir. 
     In other infusion systems an infusion pump is provided which applies a force on the fluid in the reservoir or along the infusion tubing to cause the fluid to move into the patient at the intravenous access site. One form of infusion pump acts on a medicament containing vessel in the form of a syringe by merely pushing on the plunger of the syringe at its proximal terminal end to deliver a medical preparation from the syringe. Such infusion pumps generally include some form of complicated electromechanical linear displacement transducer which converts an electric signal from a controller into mechanical motion in the form of linear motion acting on the plunger, to cause dispensing of the medical preparation from the syringe reservoir. The linear displacement transducer can be in the form of a solenoid type device or in the form of some form of motor, such as a stepper motor acting upon a rack and pinion type gear to convert rotating motion into linear motion. Other linear displacement transducers can also be utilized within such infusion pumps to convert the electric control signal into mechanical motion. 
     These electronic infusion pumps have the benefit of being able to utilize electrically driven displays and commonly available buttons and dials for thorough control of infusion rates and volumes, but also have significant deficiencies including a reliance on their internal mechanisms and a continuous source of electricity. If the power supplied from the AC plug or the DC battery is discontinued, full or partial failure of the pump may occur, causing incomplete or inaccurate medication delivery. The pump may also fail with respect to its electronic or mechanical parts within. These sorts of failures often lead to medication errors causing significant patient morbidity and mortality. These complex, expensive pumps increase the cost of delivering medical care, are cumbersome to use, require troubleshooting and frequent service. In addition, some magnetic or electric medical equipment can be interfered with by other equipment containing metal or generating electric signals, presenting a need for non-electric and/or nonmetallic infusion devices. These electronic devices cannot be used near an MRI scanner, but the patients often require ongoing infusion of their medicines, therefore a nonmagnetic/non-electronic device would be desirable. 
     Accordingly, a need exists for a simple but reliable medicament infusion system which utilizes an infusion device that does not require an electric power supply, can function reliably, and has low cost. 
     The prior art patents to Yamada (U.S. Pat. No. 5,807,337) and Mitchell (U.S. Pat. No. 5,024,664) demonstrate vacuum powered infusion devices with several limitations and have never attained significant clinical use. These devices connect the drive section to the syringe/load chamber section, which does not allow for independent operation of the two sections. This deficiency does not allow one to use the syringe section to self load by aspiration, nor does it allow one to readily discontinue and/or restart infusion by disengaging or reengaging the drive section from the medicament containing (syringe-like) section. These devices require the user to obtain and load a separate syringe so they can forcefully inject the desired medicament into the load chamber against the vacuum force of the connected drive section through a loading port which is occasionally separate from the infusion port. This obviously requires one to measure and load a separate syringe containing the medicament, attach it to the load chamber of the infusion device and apply an undue amount of finger pressure to force the medicament from the separate syringe into the load chamber as the user must overcome the vacuum force during this filling procedure. These additional steps, such as loading one syringe first to inject medicament into another, greatly increases the chance of medication error. Another limitation with these infusers is the lack of a guide or stabilizer to assure linear translation of the plungers during infusion. If the Yamada or Mitchell device plungers were significantly extended as with a significantly “full” device, there would be degree of rotation, flex and increased “play” in the apparatus which would allow increased friction and unreliable or nonlinear infusion rates. Another limitation of the Yamada and Mitchell devices is the difficulty faced with a loss of vacuum. The Mitchell device does not have a port to reestablish a vacuum should it be lost and the Yamada device has a “plug formed of a resilient material such as rubber” which requires removal in the event the vacuum needs to be replenished or if one wishes to alter the degree of vacuum force. Manipulation of a rubber plug is cumbersome and time consuming. Another limitation of these devices is the lack of a handle to independently operate the drive section. This deficiency is severely limiting and clearly demonstrates these devices are meant to be loaded with medicament only through the use of the second syringe as mentioned above, thereby extending the load chamber and drive section together and not allowing for independent operation of either section. This deficiency yields an inability to rapidly discontinue, start, or restart medicament infusion and maintains the load chamber in an always pressurized state making any attempt at placing medicament into the device cumbersome. 
     A prior art patent to Minezaki (U.S. Pat. No. 7,041,081) demonstrates a vacuum powered infusion device with many limitations. The device rigidly connects the drive section to the syringe/load chamber section, which does not allow for independent operation of the two sections. These deficiencies do not allow one to use the syringe section to self load by aspiration, nor does it allow one to readily discontinue and/or restart infusion by disengaging or reengaging the drive section from the medicament containing section. The device requires the vacuum section to be cocked back and locked with a “stopper capable of locking the piston at the rear end of the vacuum pump barrel against atmospheric pressure,” before the two sections are placed together, and requires the vacuum barrel to be placed “in a state in which the front end of the vacuum pump barrel of said first structure extends further forward than the front end of the liquid syringe.” One preferred embodiment of this device includes a version with the need for two medicament reservoirs connected together which is complicated and expensive. A second preferred embodiment demonstrates a rigidly aligned coaxial version which does not offer the independent functions required as the two sections are again rigidly connected. Other prior art patents Minezaki (U.S. Pat. No. 6,685,673) and Hiejima (U.S. Pat. No. 6,139,530) also demonstrate coaxial mechanisms with similar limitations. 
     Accordingly, a need still remains for a simple but effective non-electric self powered infusion device and system for delivering medicament into a patient in a reliable controlled fashion. 
     SUMMARY OF THE INVENTION 
     With this invention a medication infuser is provided which is compact and not reliant on electric power, and which includes an infusion device as part of an overall infusion assembly which is of a simple nature and yet can reliably deliver medicament from a reservoir into the patient. The overall assembly includes an infusion device coupled lateral to a standard syringe. This coupled arrangement may be reversible where the syringe is removable or may include a unification of the syringe and infuser through bonding or molding. A preferred embodiment of the infusion device includes a chamber within an outer body coupleable to the medicament containing syringe, such as by way of a clamp. A reciprocating arm is provided which is aligned with a long axis of the chamber to move into and out of the chamber. This arm has a sliding sealed piston on one end and a driver with a handle at the other end. This sliding sealed piston prevents air from passing around the arm and into a space between the sliding sealed piston and an interior of the chamber. This space can thus reliably hold a vacuum therein to provide a resistance force tending to cause the arm to move into the chamber (incursion) unless sufficient opposing forces are applied. Such opposing forces would include activating the infusion device by pulling out on the handle (excursion) or resistance by the syringe plunger as it pushes fluid out during infusion. 
     The reciprocating arm is configured so that it can rotate in a preferred form of this invention. Such rotation allows the driver to engage a plunger of the medicament containing syringe in some orientations and be free of interference with the plunger of the medical preparation containing syringe in other orientations. During infusion, the arm is generally prevented from rotation or lateral motion so that it provides stable linear force transfer for infusion to the plunger of the medication containing syringe. 
     The infusion assembly also preferably includes a valve, such as in the form of a stopcock to which the medicament containing syringe is coupled through a first port. A second port leads to an intravenous access port or other interface with a patient, typically through a flow rate regulator. The stopcock valve can have other ports, such as a port through which medicament is initially supplied for loading of the medicament containing syringe. This medicament can be supplied through a single port or through multiple ports, such as through a medical vial adapter interface or through a secondary syringe, or through both, such as when the medication within the vial needs to be measured or mixed with a diluent material such as saline before being loaded into the medicament delivery syringe. 
     This stopcock is preferably configured so that it is easily manipulated between different positions to cause flow of the medicament or constituents thereof in different directions depending on whether the medicament delivery syringe is being loaded or unloaded and whether the medicament is being supplied from a vial or syringe, or is ready to be delivered to the patient. All parts of the infusion assembly including the infusion device operate without requiring electric power or other electric systems. Furthermore, such systems do not require a particular orientation relative to gravity for effective operation. 
     OBJECTS OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provides an infusion device which is non-electric. 
     Another object of the present invention is to provide a medicament infusion device which can operate reliably and which is durable for reliable and long-term use. 
     Another object of the present invention is to provide a medicament infuser which is compact in form and easy to set up and operate. 
     Another object of the present invention is to provide a medicament infuser which can be flexibly operated in a variety of different ways, including receiving medical preparations from a variety of different initial sources and being readily activated and deactivated for flexible performance in accordance with the desires of medical professionals. 
     Another object of the present invention is to provide a low cost medicament infusion system. 
     Another object of the present invention is to provide a medicament infusion system where at least part of the system is disposable. 
     Another object of the present invention is to provide a medicament infusion system with a lower rate of medication errors. 
     Another object of the present invention is to provide a medicament infusion assembly which can be utilized to accept medicament from a variety of different initial sources, including liquid and powdered preparations, into a reservoir from which it can be infused into a patient. 
     Another object of the present invention is to provide an infusion assembly which does not require a particular orientation relative to gravity for proper function. 
     Another object of the present invention is to provide a medicament infusion system which is compatible with MRI scanners. 
     Another object of the present invention is to provide an infusion device which can infuse a medicament from a standard syringe. 
     Another object of the present invention is to provide an infusion device which can be integrated into a standard type disposable intravenous administration set. 
     Another object of the present invention is to provide a medicament infuser that may be easily attached to the patient. 
     Other further objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the infusion assembly of this invention and showing the infusion device of this invention ready to be attached to a medicament containing syringe. Also, the stopcock valve, medication bottle and associated interface, second syringe coupling to the stopcock valve and patient interface are shown. 
         FIGS. 2 and 3  are top plan full sectional views of the stopcock valve of  FIG. 1 , showing two different alternative embodiments for orientation of internal embedded fluid flow pathways within a manifold hub of the stopcock valve to provide flow as desired within the infusion assembly. 
         FIG. 4  is a perspective view similar to  FIG. 1 , but with the infusion device having been clamped onto the syringe and with the syringe shown loaded with the medicament and with the infusion device arm and driver ready to be rotated into position to drive the plunger of the syringe and deliver the medicament through the infusion assembly into the patient. 
         FIGS. 5 and 6  are top plan full section views similar to that which is shown in  FIGS. 2 and 3 , but for different orientations for the stopcock valve that correspond with  FIG. 4 . 
         FIG. 7  is a perspective view similar to that which is shown in  FIGS. 1 and 4 , but after the infusion device arm and driver has been rotated into position to act on the plunger of the syringe, and shown in the process of moving the piston to deliver medicament into the patient through the infusion assembly. 
         FIGS. 8 and 9  are top plan full sectional views similar to that which is shown in  FIGS. 2, 3, 5 and 6  but for different orientations for the manifold hub of the stopcock valve. 
         FIG. 10  is a perspective view of the stopcock valve and associated manifold hub of this invention, particularly showing an alternative manifold hub according to an alternative embodiment of this invention. 
         FIG. 11  is an exploded parts view of that which is shown in  FIG. 10 . 
         FIG. 12  is a full sectional view of that which is shown in  FIG. 10 , taken along lines  12 - 12  of  FIG. 10 . 
         FIG. 13  is a full sectional view of the stopcock valve of  FIG. 10 , taken along lines  13 - 13  of  FIG. 10 . 
         FIGS. 14-17  are perspective views of the infusion device of this invention showing the various stages in the operation of the infusion device of this invention. 
         FIG. 18  is a full sectional view taken perpendicular to a long axis of the infusion device, and particularly showing how the arm of the infusion device has portions thereof which can rotate freely relative to a faceted alignment guide opposite a distal end of the infusion device, and other positions where such rotation of the arm relative to the alignment guide is prevented. 
         FIG. 19  is a perspective view similar to  FIGS. 1 and 7 , but with the infusion section and the syringe section molded or bonded together as a single unit. 
         FIG. 20  is a perspective view similar to  FIG. 7 , but with a dampening system shown consisting of a dampening cylinder attached to the infusion device body and a dampening rod attached to the force activator section (force activator is equivalent to the arm and driver together). The dampening system becomes active by allowing interaction of the cylinder and rod when the infusion device interacts with the syringe during infusion and allows infuser incursion at a controlled, desired infusion rate. The dampening system components (cylinder and rod) may be reversed with respect to their location. 
         FIG. 21  is a perspective view similar to  FIG. 7 , but with the infusion driver&#39;s handle and thrust area oriented differently. Here the thrust area is positioned on the end of the driver&#39;s loop like handle, rather than that location shown in the other figures where it is positioned on the transverse member more near the first bend in the arm. The handle and driver&#39;s function is still essentially identical, but there is a “loop” rather than an open “hook” formed by the handle during infusion. 
         FIG. 22  is a perspective view demonstrating the infusion system medicament syringe being integrated into a disposable intravenous administration set (commonly utilized in the practice of IV administration which connects the fluid to be infused with the IV catheter in the patient&#39;s vein) where it may accomplish the goals set forth in this disclosure, but with a step saved as it allows the infusion device to be already integrated into the “intravenous administration set,” thereby not requiring connection. This arrangement may allow a solitary integration or it may be placed in the position of the “drip chamber” and utilized for both functions (infuser and drip chamber), if so desired by the manufacturer or practitioner. This integration is shown with the syringe in the position of the drip chamber thereby acting as the drip chamber and as a syringe adapted to infuse. The infuser is positioned lateral to the syringe but not connected in this figure. 
         FIG. 23  is a perspective view of an infuser and syringe provided according to an alternative embodiment of the invention of this application, featuring a clamp assembly and retainer structure for holding the syringe to the infuser. 
         FIGS. 24-28  are perspective views of the infuser and syringe of  FIG. 23  in various different stages of interfacing together, and action of the infuser upon the syringe to drive fluids out of the syringe according to a method of this invention. 
         FIG. 29  is an exploded parts view of that which is shown in  FIG. 23 . 
         FIG. 30  is a detail of a portion of that which is shown in  FIG. 23  revealing details of a system featuring one-way biased O-rings. 
         FIG. 31  is a perspective view of the driver with one-way biased O-rings shown separated from other portions of the infuser. 
         FIG. 32  is a perspective view of a pair of infusers and a pair of syringes all assembled together illustrating one assembly which can be configured utilizing the infuser and syringe of this invention. 
         FIG. 33  is a perspective view of an alternate infuser which has a clamp assembly and retainer structure which are configured to facilitate attachment of three syringes to a single infuser. 
         FIG. 34  is a perspective view of an alternative embodiment gas driven infuser and associated syringe. 
         FIG. 35  is a perspective view of an alternative embodiment motorized infuser and syringe. 
         FIG. 36  is a perspective view of an alternative embodiment torsion spring driven infuser and associated syringe. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral  10  is directed to an infusion device for use with a syringe S, such as within an overall infusion assembly  2  for delivery of medicament over time from the syringe S into a patient or animal. The infusion device  10  utilizes a vacuum or another resistance based force to energize and “activate” the arm  40  and driver  50 . The arm  40  and driver  50  together are known as the force applicator and when activated, may act upon a plunger P of the syringe S so that a piston J within the syringe S moves to drive the medicament out of the syringe S and to the patient. 
     In essence, and with particular reference to  FIG. 1 , basic details of this invention are described, according to a preferred embodiment. The infusion assembly  2  in this preferred embodiment includes the infusion device  10  removably coupleable (along arrow F) to the syringe S. The syringe S is coupled to a stopcock valve  60  which has separate ports which act as inlets or outlets into or out of other portions of the infusion assembly  2 . These ports A, B, C, D can lead to a second syringe T, a vial adapter  90  adapted to receive and assist in removal of a medicament from a medication bottle M, and a patient interface generally in the form of a regulator  80 , a tube  82  and a connector  84 . The regulator  80  may be integrated into the stopcock valve  60 , the tube  82 , or the connector  84 , or may simply be accomplished by having small bore tubing  82  of appropriate diameter and length to act as a flow resistance regulator itself. The stopcock valve  60  includes a housing  62  which supports a manifold hub  70  therein. By rotation of the manifold hub  70 , different ports A, B, C, D within the stopcock valve  60  are brought into fluid communication with each other for passage of fluid between the aligned ports and equipment coupled to these ports. 
     In the most preferred embodiment the infusion device  10  includes a body  21  around a chamber  20  in which a vacuum can be drawn. This vacuum chamber  20  can be replaced with a spring, gas cylinder or other resistance force based energizing means. A clamp  30  is coupled to the body  21  in this embodiment which allows the infusion device  10  to be snapped onto the syringe S, or the syringe S to be snapped into the infusion device  10  (along arrow F). A reciprocating arm  40  translates into and out of the chamber  20  with a sliding sealed piston  42  on an innermost (distal) end of the arm  40  and a driver  50  on the proximal end of the arm  40  opposite the sliding seal  42 . The driver  50  is adapted to engage the proximal terminus H of a plunger P of the syringe S to cause the plunger P to move within the syringe S and cause medicament within the syringe S to be delivered therefrom. The arm  40  is rotatable to bring the driver  50  into and out of alignment with the proximal terminus H of the plunger P of the syringe S, for selective engagement and disengagement of the infusion device  10  by rotation of the arm  40  relative to the chamber  20 . 
     More specifically, and with continuing reference to  FIG. 1 , as well as  FIGS. 4 and 7 , standard details of the infusion assembly  2  which are generally available alone in the prior art are described to provide proper context for understanding of unique details of the infusion assembly  2  of this invention. 
     The syringe S is most preferably a standard syringe having a generally cylindrical hollow body forming a cylinder and with a plunger P translating into and out of this cylinder of the syringe S. The cylinder includes a fluid conveyance port typically at a distal end and an opening surrounded by a radially extending ledge R at a proximal end which allows the plunger P to pass into and out of the interior of the cylinder. The plunger P includes a proximal terminus H on a proximal end thereof and a piston J on an end of the plunger P opposite the proximal terminus H. The piston J includes seals thereon so that fluid cannot move around the piston J as the piston J moves within the syringe S cylinder. The fluid conveyance port of the syringe S is adapted to be coupled to one of the ports of the stopcock valve  60 . In this exemplary embodiment, the syringe S is shown with the fluid conveyance port coupled to port C of the stopcock valve  60 . Such a connection can merely be through a “luer” type fitting or some other type of coupling which is preferably a coupling which can be removably attached. 
     Because this syringe is preferably of a standard type, it would typically have graduation lines on a side of the body and associated indicia representative of volumetric capacity of the syringe S with the piston J at various different positions within the syringe S. With the syringe S in the form of a standard syringe in this preferred embodiment, the syringe S can be used in a variety of different ways known in the art either before or after attachment to the stopcock valve  60  (e.g. by utilizing any known technique for loading a syringe S before attachment to the stopcock valve  60  and utilization with the infusion assembly  2 ) or for loading of the syringe S in standard ways through the stopcock valve  60 , or for manipulation of the syringe S manually by a user pushing on the plunger P of the syringe S when such manipulation of the syringe S is desired by a medical professional. 
     In addition to the syringe S, a second syringe T can be coupled to one of the ports. In this embodiment, such a second syringe T is shown attached to port B of the stopcock valve  60 . The second syringe T can act as a medicament container, a measuring device or a mixing device, such as for accurately measuring a dose of medication or mixing a saline solution with a medication to properly measure, mix or dilute a medication contained in syringe T (or syringe S) or in a medication vial attached to another port before transferring the medication into the syringe S for delivery through the infusion assembly  2  of this invention. This capability would give the medical professional the ability to dilute a powdered (or liquid) medication attached at another port while in place, then dilute it, mix it, measure it, and transfer it to the syringe S for infusion. The second syringe T can also be utilized for holding a second volume of like or different medication which could either be co-infused along with a first medical preparation within the syringe S, or to be utilized on an itinerant basis at the direction of the medical professional. The second syringe T preferably interfaces with port B the same way that the syringe S interfaces with port C. Such syringes S, T and other components of the infusion assembly  2  can be coupled to any one of the ports A, B, C, D without any particular requirement that any particular component of the assembly  2  be coupled to any particular port A, B, C, D. 
     A medication bottle or vial M is known in the prior art which contains a medication and with a septum L often at an interface on the medication vial through which a needle can pass to draw a medical preparation out of the vial M. In this preferred embodiment, the infusion assembly  2  includes a vial adapter  90  with associated needle  92  extending axially therein. The vial adapter  90  and needle  92  are preferably coupled to one of the ports (port A in  FIGS. 1, 4 and 7 ) of the stopcock valve  60 . Such a coupling can be similar to the coupling for attachment of the second syringe T or syringe S to the stopcock valve  60  through other ports B, C. Thus, a medication vial M can be inserted into the vial adapter  90  and a needle  92  can pierce the septum L of the medication vial M. The medical preparation (medicament) can then be drawn out of the medication vial M through the needle  92  and into the stopcock valve  60  for delivery to any of the other portions of the infusion assembly  2  coupled to the stopcock valve  60 . 
     The vial adapter  90  is available as prior art and typically somewhat cylindrical and open at one end. It is typically long enough to prevent or discourage fingers of a medical professional from bumping into the tip of the needle  92 . Also, the vial adapter  90  helps to align the medication bottle M with the needle  92  so that the needle  92  can reliably hit the septum L and penetrate the septum L. The vial adapter  90  can have different diameters to accommodate different medication bottle sizes or could otherwise be configured to more flexibly accommodate different medication vials M of different sizes while still providing some degree of protection from inadvertent contact with the needle  92 . 
     With these various components of the infusion assembly  2  which are known in the prior art being able to interface with the stopcock valve  60 , the infusion assembly  2  is provided with equipment that is familiar to medical professionals so that the operation of the infusion assembly  2  is simple and intuitive for the medical professional. Furthermore, flexibility in the interconnection of various medical components is to some extent facilitated by the interchangeability of the ports in the stopcock valve  60  and the general configuration of the infusion assembly  2  which allows for flexible arrangement of different medical equipment into the infusion assembly  2 . 
     The fourth port D of the stopcock valve  60  typically is coupled to some form of patient interface, such as through a tubing  82 , a regulator  80  and a connector  84 . The regulator  80  may be a discreet part or may be integrated into the stopcock  60 , tubing  82  or connector  84 . The regulator  80  can act as a fixed or adjustable control for flow rates into the patient. If adjustable, it would typically have dials, buttons or some other manipulatable interface and perhaps a display indicating its current setting. The tubing  82  is preferably flexible and elongate so that the infusion assembly  2  is not required to be located too close to the patient. The connector  84  would typically be in the form of a male luer lock adapter, a simple intravenous access needle, or any other form of prior art connector able to connect into the patient&#39;s intravenous, intraarterial, intraosseous, or other body lumen system as desired by the medical professional. 
     With continuing reference to  FIGS. 1, 4 and 7  primarily, details of the infusion device  10  of the infusion assembly  2  are described. While the infusion device  10  is described in conjunction with the entire infusion assembly  2 , it is conceivable that the infusion device  10  could merely be used with a single syringe S directly coupled to some form of patient interface without the stopcock valve  60 . Furthermore, the infusion device  10  could conceivably be utilized for distribution of any fluid from the syringe S even in a non-medical environment, such as in a laboratory or industrial setting for timed release of a fluid. Furthermore, the infusion device  10  might be utilized on a syringe S for delivery of a fluid within some form of manufacturing process where delivery of a fluid at a somewhat regular rate over time is required, and where it is desired that the infusion device  10  exhibit the simplicity and non-electric nature of the infusion device  10  of this invention. 
     The infusion device  10  in this preferred embodiment utilizes an energy storage and resistance force application principle (resistance force energizer) that is generally associated with a vacuum within a chamber  20  of the infusion device  10 . It is known that within the atmosphere and in other environments where a fluid pressure is present, that if a vacuum is formed in a particular location that forces are exerted to tend to close up this vacuum space. Essentially, in our atmosphere the air within the atmosphere pushes on all walls of the vacuum space to try to close up this vacuum space. Such a force is utilized by the infusion device  10  in this preferred embodiment to provide the force required to act on the syringe S to cause delivery of medicament into the stopcock valve  60  for operation of the infusion assembly  2  of this invention. 
     The preferred embodiment infusion device  10  is generally configured similarly to a standard medical syringe. The body  21  and chamber  20  are thus generally cylindrical in form and elongate along a central axis. One end of the chamber  20  is closed defining a distal end  22 . This distal end  22  preferably includes a port with a form of closure  24  such as a cap or an open/close valve. Such a distal port and closure  24  are useful in that they allow installation of an arm  40  with an associated sliding sealed piston  42  into the chamber  20  and evacuation of any air or other fluids within the chamber  20  during such installation or such as to restore the vacuum state within the chamber  20  should it ever be lost for any reason (such as removal of the arm  40  or extension of the sliding sealed piston  42  too far out of the chamber  20 , causing loss of the vacuum state within the chamber  20 ). 
     A ported base  26  is provided on the proximal aspect of the infusion device body  21  opposite the distal end  22  acts as a proximal end of the chamber  20  which is generally perpendicular to the long axis of the body and does retain the sealed piston  42 , but is not a fluid tight barrier in the vacuum powered version because atmospheric pressure must reach the proximal side of the sealed piston to impart its force on the piston (as the vacuum chamber exists on the distal side of the piston). In a preferred embodiment, this ported base  26  includes a faceted alignment guide  28  which provides an opening through which the arm  40  can reciprocate. 
     In a most preferred embodiment of this invention this faceted alignment guide  28  has facets thereon which only allow the arm  40  to translate therethrough when the arm  40 , having matching or corresponding facets  46 , is properly aligned for passage through the faceted alignment guide  28 . In other orientations of the arm  40 , the faceted alignment guide  28  can interact with facets  46  on the arm  40  to prevent arm  40  translation through the faceted alignment guide  28  of the ported base  26 . 
     The chamber  20  may be sized larger, smaller or similarly to the syringe S to provide various different degrees of force application and various different associated infusion rates for the infusion device  10 . Typically, the chamber  20  is formed of plastic materials similar to those from which syringes are typically formed. The contour of the chamber  20  is preferably formed to be amenable to manufacture by injection molding or similar low cost manufacturing processes so that the infusion device  10  can be manufactured in a precision manner at low cost to desirably provide both robust and low cost performance to the user. 
     A clamp  30  is included with the infusion device  10  for attachment of the infusion device  10  to the syringe S. In this preferred embodiment, the clamp  30  is coupled directly to the body  21  of the infusion device  10 . The clamp  30  is elongate in form, and typically having a length approximating the syringe S length. The clamp  30  is attached to the body  21  through a joint  32  which is preferably fixed so that the clamp  30  does not move relative to the body  21  and may be molded with the body  21  as a unit. 
     The preferred clamp  30  is a semi-cylinder of hollow nature so that it has an inside wall  34  forming a portion of a cylinder and an outside wall  36  forming a portion of a cylinder (although shapes other than a cylinder could be utilized as an effective clamp). Edges  38  define ends of these walls  34 ,  36 . Preferably, the clamp  30  is slightly more than half of a full cylinder. Thus, the edges  36  extend slightly toward each other and are closer to each other than a diameter of the cylindrically shaped clamp  30 . The clamp  30  is preferably formed of sufficiently resilient material that the edges  38  can be flexed away from each other slightly. This material is also preferably sufficiently elastic that the clamp  30  will apply a clamping force tending to cause the clamp  30  to return at least partially back toward an original state and continue to maintain an inwardly directed clamping force to help the clamp  30  securely attach to the syringe S. 
     Furthermore, the clamp  30  has a proximal end  39  which is preferably substantially planar and perpendicular to a long axis of the clamp  30  and chamber  20 . This proximal end  39  is configured to abut against the ledge R at the proximal end of the syringe S. One such ledge R is shown in  FIGS. 1, 4 and 7  on a front side of the infusion assembly  2 . However, such a ledge R typically extends at two locations opposing each other on opposite sides of the syringe S, with a rearward ledge hidden behind the body of this syringe S, but having a similar form to that of the ledge R on the front side that is shown in  FIGS. 1, 4 and 7 . 
     The distal aspect of At least one of these ledges R on the syringe S provides an abutment surface for the proximal end of the clamp  30  so as to prevent translation of the infusion device  10  proximal to the syringe S and although not shown in the figure, an additional abutment surface attached to the body  21  and abutting upon the proximal aspect of the ledge R could be added to reduce translation of the infusion device  10  distal to the syringe S. With such an interface against the ledge R, it is not strictly necessary that the clamp  30  grip the syringe S sufficiently strongly to prevent translation of the clamp  30  and body  21  of the infusion device  10  along a central axis of the infusion device relative to the syringe S. Rather, the clamp  30  need merely provide sufficient force to keep the infusion device  10  on the syringe S, with the interface between the proximal end  39  of the clamp  30  and the ledge R preventing axial translation between the syringe S and the infusion device  10 . 
     Thus, the clamping force  30  that must be overcome to snap the clamp  30  onto the syringe S (along arrow F of  FIG. 1 ) does not need to be so great that it can also act to hold the infusion device  10  without translation relative to the syringe S. Vacuum forces within the chamber  20  and acting on the arm  40  can be quite high, and hence forces tending to translate the infusion device  10  longitudinally relative to the syringe S can be quite high. Because the clamping force requires factoring in of friction between the clamp  30  and the syringe S, clamping forces of the clamp  30  would need to be exceptionally high to alone prevent translation of the infusion device  10  relative to the syringe S. By having the proximal end  39  of the clamp  30  abut the ledge R, clamping forces  30  can be kept at a relatively low level so that even a medical professional with limited strength can easily attach and detach the infusion device  10  onto and off of the syringe S. 
     With continuing reference to  FIGS. 1, 4 and 7 , details of the arm  40  and associated driver  50  of the infusion device  10  are described, according to this preferred embodiment. The arm  40  provides the preferred form of interconnection between a sliding sealed piston  42  which slides within the chamber  20  and a driver  50  which is a preferred form of interface with the plunger P of the syringe S. This arm  40  is preferably an elongate substantially rigid structure sized to reside within the chamber  20  and reciprocate (translate axially) within the chamber  20  along a central axis thereof. 
     The sliding sealed piston  42  is provided at a distal end of the arm  40 . This sliding sealed piston  42  is similar to the piston J of the syringe S, and is configured to have a friction fit against interior walls of the chamber  20 , and formed with a sufficiently rigid material so that a fluid-tight fit is provided between the sliding sealed piston  42  and walls of the chamber  20 . Thus, as the arm  40  reciprocates into and out of the chamber  20 , the sliding sealed piston  42  also moves within the chamber  20  and a volume of a vacuum space between the sliding sealed piston  42  and the distal end  22  within the chamber  20  is caused to increase and decrease in size. 
     A preferred embodiment of the infusion device includes the sliding sealed piston  42  coupled to a free end  44  of the arm  40  which extends most deeply into the chamber  20 . This free end  44  preferably is configured with a neck  45  defining a portion of the arm  40  which has a slightly smaller cross-sectional diameter than other portions of the arm  40 . This cross-sectional diameter is preferably also circular in form, but also could have other shapes and still function as the neck  45  provided that it is either smaller in size or closer to round than other portions of the arm  40 . 
     The arm  40  extends proximally away from the free end  44 , the neck  45  preferably transitions into series of facets  46  which provide the arm  40  with a cross-sectional shape which remains constant but which is faceted rather than circular in form. These facets  46  can take on a variety of different configurations including convex and concave angles. In a simplest form of the invention, four similarly sized facets are provided so that the arm  40  has a generally square cross-section. 
     This contour for the cross-sectional shape of the arm  40  is similar to that of the faceted alignment guide  28  of the chamber  20 . Thus, the arm  40  can translate through the faceted alignment guide  28 , but the arm  40  is prevented from rotating relative to the faceted alignment guide  28 . However, when the neck  45  portion of the arm  40  is aligned with the faceted alignment guide  28 , such rotational restriction is eliminated and the arm  40 , sliding sealed piston  42 , as well as the driver  50  can be rotated as a unit relative to the chamber  20 , body  21  and clamp  30  (arrow G of  FIGS. 4 and 15 ). When the arm  40  is moved so that it is not aligned with its neck  45  portion adjacent the faceted alignment guide  28 , then the faceted portion  46  of the arm  40  will be mated with (and cooperating with) the faceted alignment guide  28 . This will tend to keep the arm  40  highly stable and precisely aligned along a central axis of the chamber  20  so that the driver  50  will remain precisely aligned with the proximal terminus H of the plunger P of this syringe S, to provide the infusion device  10  as a very stable force applying means, acting on the syringe S for infusion therefrom (along arrow K of  FIGS. 7 and 16 ). The force that the infusion device applies during incursion (translation inward), to the syringe proximal terminus, will be translated to actual work performed on the syringe plunger as the plunger moves inward causing infusion of medicament. 
     An end of the arm  40  opposite the free end  44  includes a bend  48  thereon which transitions into the driver  50 . The driver  50  is an extension or transition of the arm  40  which includes a handle  58  and a thrust area  52 ,  54 . The thrust area  52 ,  54  can interface with and thrust the proximal terminus H of the plunger P of the syringe S to cause infusion. In a preferred form of the invention, the driver  50  thrust area  52 ,  54  includes an engagement plate  52  and associated rim  54 . The engagement plate  52  is generally planar and oriented perpendicular to the central axis of the chamber  20 . This plate  52  preferably includes a cylindrical rim  54  extending distally from a perimeter of the plate  52 . This rim  54  has a diameter slightly greater than the proximal terminus H of the plunger P of the syringe S, with the proximal terminus H typically being substantially round. Thus, when the proximal terminus H is adjacent the engagement plate  52 , the rim  54  keeps the driver  50  aligned with the proximal terminus H to further assist in stabilizing the assembly of the infusion device  10  clamped to the syringe S. The rim  54  may not need to encompass the entire perimeter, but only a portion adequate to resist any movement of the proximal terminus H. 
     In  FIGS. 1, 4, 7, 14, 15, 16, 17 and 18  a transverse member  56  extends from the bend  48  to a rear side of the plate  52  to interconnect the engagement plate  52  to the arm  40 . This transverse member  56  preferably further bends to form a hook  58 . Such a hook  58  can be utilized to suspend the entire infusion assembly  2 , or at least the infusion device  10  and associated syringe S from an elevated support, if desired. In such an arrangement, the hook  58  would end up being the highest portion of the entire infusion assembly  2 . This hook  58 , also acts as a handle  58  which can be gripped by a user for pulling of the driver  50 , arm  40  and sliding sealed piston  42  (along arrow E of  FIGS. 4 and 14 ) against the resistance force (which in this embodiment includes the sliding sealed piston forced distally by the vacuum force) and for ease in rotation of the same structures (along arrow G of  FIGS. 4 and 15 ). An embodiment shown in  FIG. 21  demonstrates an alternate, but equivalently desirable design for the driver  50 , handle  58  and thrust area  52 ,  54 . In this embodiment the thrust area with the plate  52  and rim  54  are affixed to the distal most aspect of the handle  58 , leaving a loop rather than a hook, when the infusion device  10  is actively engaged with the syringe S. 
     The driver  50  and arm  40  act as a preferred form of force application member (force applicator) to apply a linear force on the plunger P of the syringe S. In this embodiment, the driver  50  is caused to move by action of the arm  40  and the sliding sealed piston  42  being drawn into the vacuum between the sliding sealed piston  42  and the distal end  22  within the chamber  20 . Provided that a pure vacuum exists between the sliding sealed piston  42  and the distal end  22  of the chamber  20 , this force remains entirely constant and is proportionate to the atmospheric pressure outside of the vacuum chamber  20 . Thus, a constant force is applied to the syringe S for discharge of medicament over the entire length of force applicator incursion. 
     In alternative embodiments, the vacuum chamber  20  can be replaced with some other form of energy storage and resistance force application principle (resistance force energizer). For instance, a tension spring could be placed between the driver  40  and a surface generally attached to the body  21 . The spring would tend to hold the force applicator (arm  40  and driver  50 ) at its resting point (maximum incursion) until the user applies energy to produce excursion of the force applicator  40 ,  50 , thereby stretching the tension spring and activating the infuser. The spring would then exert a force tending to return the force applicator  40 ,  50  back to its resting point, thereby inducing forced incursion (inward movement) of the driver  50  which would perform useful work on the syringe plunger P. Simultaneously, the driver  50  could supply this force to the plunger P of the syringe S. 
     As another alternative, the infusion device body  21  could contain a compressed gas chamber rather than a vacuum chamber  20 . Such a compressed gas chamber would typically be located on the proximal side of the sliding sealed piston  42 , between the sliding sealed piston  42  and the ported base  26 . This would require a fluid tight seal on the proximal aspect of the chamber near the ported base  26  and alignment guide  28 . Another compressed gas force energizer could include a compressed air cartridge removably attachable to such a compressed gas reservoir and provide a force proportionate to the difference between the pressure within the compressed air source and atmospheric pressure. If this compressed air supply is sufficiently high in pressure, as the driver  50  would move, along with any sliding sealed piston  42  coupled thereto, the pressure differential would reduce slightly relative to atmospheric pressure but would be sufficiently small that a substantially constant force would be applied to the syringe S. Other analogous alternative resistance force energizers could also be provided. 
     The resistance force energizers (vacuum chamber  20 , spring, compressed gas, etc.) will tend to hold the force applicator  40 ,  50  at its resting point, but can also act as an energy storage device when the force applicator (arm  40  and driver  50 ) section is locked out in some degree of excursion and temporarily held there by an interaction between the arm  40  and the infusion device base  26 . In the preferred embodiment, such locking of the arm  40  relative to the base  26 , through interaction of the facets  46  on the arm  40  with the faceted alignment guide  28  of the body  21  causes potential energy to be stored equivalent to the resistant force that is applied to the arm  40  multiplied by the distance that the force applicator (arm  40  and driver  50 ) and sliding sealed piston  42  have been translated outward (excursion). In the case of a spring, the potential energy is the distance traveled by the spring when the arm  40  or similar structure is able to move, multiplied by the spring force for the spring. 
     With particular reference to  FIGS. 2, 3, 5, 6, 8 and 9 , details of the stopcock valve  60  according to a preferred embodiment are described. In some of these embodiments ( FIGS. 2, 5 and 8 ), a manifold hub  70  is provided according to the most preferred embodiment. In other figures ( FIGS. 3, 6 and 9 ) an alternative manifold hub  170  is provided. For each of these stopcock valves  60 , a common housing  62  is provided. 
     This housing  62  is generally a short hollow cylinder in form which is open on one side so that it has a recess  64  therein which is generally cylindrical and generally with a diameter greater than a depth thereof. This recess  64  has its periphery defined by a wall of the housing  62  which is generally cylindrical and includes the ports A, B, C, D therein, preferably each in a common plane spaced 90° away from each other and extending radially away from a central axis of the housing  62 . 
     As an alternative, only three ports could be provided (one for a source of medicament, such as the second syringe T or vial adapter  90 , one for the syringe S and one for the patient infusion interface  84 ). Preferably, the ports A, B, C, D are generally cylindrical in form with central axes thereof extending radially away from a central axis of the housing  62  and with the ports A, B, C, D and housing  62  all formed together or rigidly attached together as a single construct. 
     The manifold hub  70  resides within the recess  64  and provides for fluid access between at least two of the ports A, B, C, D depending on the orientation of the manifold hub  70  within the recess  64 . This manifold hub  70  is preferably substantially cylindrical in form and has a size and shape which allows it to fit snugly within the recess  64 , but with rotation allowed about a central axis of the housing  62  (along arrow I of  FIGS. 2-10 ). This manifold hub  70  includes a selector  72  in the form of an arm which is preferably raised from a face  73  and extends beyond a perimeter of the manifold hub  70 . The selector  72  can be grasped manually and turned to set the valve  60  as desired. 
     The manifold hub  70  can be hollow or solid but is particularly characterized by one or more fluid flow paths contained therein. Most preferably, the manifold hub  70  includes a central fluid flow path  74  which extends linearly and radially through the manifold hub  70 , so that it can align ports A, C or ports B, D which are opposite each other directly together when the central fluid flow path  74  is aligned with such ports A, C or ports B, D. 
     However, in a most preferred embodiment, the tolerances followed in forming the manifold hub  70  and the housing  62  are preferably sufficiently tight that the manifold hub  70  is prevented from undesirable rotation within the housing  62 , and also a fluid tight fit is accomplished. Other techniques for leak prevention or mitigation can also be utilized, as is known in the art, for such valves. 
     In the manifold hub  70 , a preferred orientation of additional fluid flow paths demonstrates a first side leg  76  and a second side leg  78  are also provided which extend radially from a center of the manifold hub  70  and at angles 90° spaced from each other and 45° spaced from ends of the central fluid flow path  74 . With such a configuration, the first side leg  76  and second side leg  78  can be aligned with adjacent ports A, B, C, D for passage of fluid between any two adjacent ports A, B, C, D depending on the position of the manifold hub  70 , as controlled by gripping and rotation of the selector  72  (along arrow I). 
     With particular reference to  FIGS. 3, 6 and 9-13 , details of an alternative manifold hub  170  are described. This alternative manifold hub  170  is preferably similar to the manifold hub  70  except that fluid fluid flow paths therein are routed somewhat differently. In particular, a selector  172  and face  173  are similar to those of the manifold hub  70 . A first fluid flow path  174  is provided which is linear and extends radially through a middle of the alternative manifold hub  170  with no intersections at midpoints thereof. A second fluid flow path  176  is also provided which is positioned lateral and parallel with the first fluid flow path  174 , but is laterally spaced from the first conduit  174 . A version of the second flow path  176 , which is not shown, may be non linear and skirting along the periphery of the manifold hub  170 , but having openings on each side that would coincide with those shown on the second fluid flow path  176 . Sleeves  175  can be provided as depicted in  FIG. 11 . 
     The second fluid flow path  176  is positioned so that ends thereof are spaced 45° away from ends of the first fluid flow path  174 . Thus, ends of the first fluid flow path  174  and second fluid flow path  176  are similarly placed as ends of the central fluid flow path  74  and legs  76 ,  78  of the manifold hub  70  ( FIGS. 2, 5 and 8 ). By rotation of the manifold hub  70 ,  170  relative to the housing  62  (along arrow I of  FIGS. 2-10 ), ends of the fluid flow paths  74 ,  76 ,  78 ,  174 ,  176  can be brought into alignment with various different ports A, B, C, D to route medical preparations or other fluids through the stopcock valve  60  in a manner desired. 
     Preferably, the face  73  is printed with indicia which provide an indication as to where these fluid flow paths are within the manifold hub  70 ,  170 . Preferably, the selector  72  is provided extending radially at a location spaced from this indicia so that the selector  72  does not block the indicia from being easily viewed by a user. A user merely orients the indicia so that they are aligned with the ports A, B, C, D which the user desires to have brought together into fluid communication, and then the manifold hub  70 ,  170  is set properly for proper operation of the stopcock valve  60 . Such indicia are also useful in allowing a medical professional to, at a quick glance, verify that the stopcock valve  60  is set at the proper position, such as when inspecting a patient&#39;s care regimen. 
     In use and operation, and with particular reference to  FIGS. 14-18 , details of the operation of the infusion device  10  are described, according to a preferred embodiment. Initially, a user has the option of first snapping the infusion device  10  onto the syringe S (arrow F of  FIG. 1 ) or first charging the chamber  20  with a vacuum by excursion (movement of the driver  50 , arm  40  and associated sliding sealed piston  42  proximally out of the chamber  20 ) of the force applicator via its handle  58 , as shown in  FIG. 14 . Upon such movement, a vacuum is drawn within the chamber  20  and potential energy is induced, yielding a state of “activation.” If some time will elapse before the infusion device  10  will be utilized or if a pause is required, the force applicator may be reversibly disabled while in this activated state. This disabling requires the handle  58  of the driver  50  to be rotated (arrow G of  FIGS. 4 and 15 ) so that the facets  46  on the arm  40  no longer are aligned with the facets on the faceted alignment guide  28 . Thus, when the handle  58  of the driver  50  is released, and the vacuum pulls (actually the atmosphere pushes) the arm  40  toward the vacuum chamber  20  distally, the facets  46  on the arm  40  abut the faceted alignment guide  28  in this nonaligned disabling configuration to prevent further movement of the arm  40  into the chamber  20 . This activated but disabled configuration allows the device to store the potential energy. Other potential mechanisms exist for disabling the force applicator while activated including a pin or sliding plate that could be reversibly attached to the arm at various positions but not being able to traverse through the alignment guide, thereby halting incursion of the arm and infusion. 
     By providing four facets  46  on the arm  40  and four facets on the faceted alignment guide  28 , and a generally square cross-section for each, rotation of the arm  40  (along arrow G) 45° from the disabled configuration about a central axis thereof will cause the infusion device  10  to transition back from a disabled potential energy storage orientation to an enabled energy delivering force applicator (and vice versa). 
     Such rotation of the arm  40  (about arrow G of  FIGS. 4 and 15 ), can both be used to put the infusion device  10  into a potential energy storage orientation, but also can be utilized to provide clear access to the plunger P of the syringe S or to engage the driver  50  of the infusion device  10  with the proximal terminus H of the plunger P of the syringe S. For instance, after the infusion device  10  has been snapped on to the syringe S (arrow F of  FIG. 1 ) and after a vacuum has been drawn on the chamber  20  (by movement along arrow E of  FIGS. 4 and 14 ) and after the arm  40  has been rotated slightly (about arrow G of  FIG. 15 ) while the neck  45  of the arm  40  is aligned with the faceted alignment guide  28 , so that the infusion device  10  is in a potential energy storage orientation, the piston P of the syringe S can still be easily accessed. In such an orientation, a user can load the syringe S in a typical fashion, such as by pulling on the proximal terminus H of the plunger P to cause medicament to be drawn into the syringe. Such a loading of the syringe S can occur with medicament being supplied from another syringe such as the second syringe T, or from a medication vial M, or from some other source coupled to the stopcock valve  60  through one of the ports A, B, C, D. As another alternative, the syringe S could be a preloaded syringe or it could be loaded from a proximal end, or it could be removed from the stopcock valve  60  altogether and loaded in some other fashion. 
     Once the syringe S has been loaded and is ready for infusion, the arm  40  is further rotated so that the driver  50  can be aligned with the proximal terminus H of the plunger P of the syringe S. The driver  50  is then released slightly until the engagement plate  52  abuts the proximal terminus H of the syringe S. Force is now being applied to the plunger P of the syringe S and medicament is being delivered from the syringe S and through the stopcock valve  60  and into the patient through the patient interface section and its connector  84 . 
     The stopcock valve  60  would first be rotated appropriately (along arrow I) so that fluid flow would occur toward the patient interface section  80 ,  82 ,  84 . Such force application occurs along arrow K of  FIGS. 7 and 16 . Because the force occurs at a constant rate, as the force associated with the vacuum remains constant, a constant force is applied to the syringe S for delivery of the medicament at a constant rate. This force can be modified by modifying a volume of the chamber  20 , such as by modifying a diameter of the chamber  20 . Thus, different size infusion devices could be provided having different forces and hence different flow rates. As another alternative, the regulator  80  can be utilized for such flow rate regulation. Other flow restrictions at other locations, including at an interface between the syringe S and the stopcock valve  60  or as a function of the tubing itself could also alternatively be utilized for such infusion rate control. 
     If a user desires to provide an additional surge of medical preparation into the patient through the patient interface  80 ,  82 ,  84 , a medical professional can merely push on the handle  58  of the driver  50  to enhance the force that is otherwise being provided by the interaction of the atmosphere and the vacuum chamber  20  (or they could change the flow direction through the stopcock valve  60  to exit another port with a decreased or absent flow regulator  80 ). Similarly, infusion can be temporarily or permanently stopped by merely pulling on the handle  58  of the driver  50  (along arrow B of  FIG. 14 ) in the middle of an infusion process to pull the driver  50  off of the proximal terminus H of the plunger P of the syringe S, until the neck  45  of the arm  40  is aligned with the faceted alignment guide  28 . Then, the force activator with its arm  40  can be rotated slightly (along arrow G) to cause energy storage once again. The syringe S will then sit idle and disabled with no medicament infusing until the infusion device  10  is again positioned with the driver  50  acting on the proximal terminus H of the plunger P of the syringe S. Thus for instance, if the patient interface  80 ,  82 ,  84  requires adjustment, the infusion device  10  can be easily stopped and restarted in the midst of infusion. The infusion process may also be readily discontinued by truly deactivating the force activator. This deactivation discontinues infusion as well and is accomplished by pulling the force activator back to its neck, rotating it (and its arm  40 ) a full 90° or 180° in either direction to another corresponding faceted position (where the faceted arm may again undergo incursion through the faceted alignment guide, but with incursion occurring where the engagement plate will not interact with the syringe proximal terminus) where the force activator can be let down to its resting point thereby releasing the stored potential energy and stopping the infusion process. 
       FIG. 22  demonstrates an infusion syringe S “built in” to a typical disposable intravenous (IV) administration set. The syringe S is placed proximally in the set in an “inline” configuration and in this embodiment also takes the place of the “drip chamber” which is typically present in the prior art administration sets. 
     The  FIG. 22  preferred embodiment shown demonstrates the IV fluid flow path which would deliver the IV fluid from a plastic bag into the stopcock (not shown, but from stopcock port A to port C) and into the syringe S via the port at the distal tip (stopcock port C would typically be directly connected to the port at the syringe distal tip, but for clarity, it is shown adjacent in this figure). The IV fluid would enter the syringe tip through an embedded “drip needle”  101 , so that dripping IV fluid  102  could be visualized and quantified by counting drips per minute as it drips into the medicament reservoir  104 . The IV fluid or medicament in the medicament reservoir  104  exits via a second port called the piston fluid conveyance port  105  (positioned on the syringe piston J and allowing fluid conveyance through the piston J and into the IV fluid tubing  106  where it may traverse down along the syringe plunger P (or within the plunger P) through further IV fluid tubing  106  and eventually into the patient&#39;s vein). This embodiment would save the practitioner the trouble of locating a separate syringe for medicament delivery as it would already be present in the IV administration set where it could be utilized in similar fashion to descriptions of this invention noted elsewhere in this disclosure. 
     With reference to  FIGS. 23-33 , details of a specific embodiment of the infuser  410  of this invention are disclosed along with an exemplary syringe S in practicing the system and method of this invention. Referring to  FIG. 23  primarily, an infuser  410  is depicted which includes a chamber  420  in which a vacuum can be drawn. A piston  442  translates within the chamber  420  and is coupled to an arm  440  which extends out of the chamber  420 . A driver  450  is located on an end of the arm  440  opposite the piston  442 . A clamp  430  assembly is located closer to a distal end of the chamber  420  with a retainer  460  located closer to a proximal end of the chamber  420 . The clamp  430  assembly and retainer  460  act together to removably couple the infuser  410  to a syringe S. 
     The clamp  430  assembly preferably has multiple stations which can support a separate syringe S. Each station preferably includes a clamp  430  which is sized to allow an outlet end of the syringe S to snap thereinto. A boss  470  is preferably located adjacent each clamp  430  with the boss  470  sized similar to the outer periphery of the outlet of the syringe. In this way, a clamp  430  can either snap onto an outlet  485  end of the syringe S or onto a boss  470  of an additional infuser  410  (see for instance  FIG. 32 ). 
     The retainer  460  also includes multiple stations with a number of stations provided on the retainer  460  generally corresponding with the number of stations provided on the clamp  430  assembly and with such retainer  460  stations aligned with the clamp  430  stations. Each retainer  460  station has a semi-circular saddle which can cradle a portion of the cylinder  486  of the syringe S therein adjacent to a flange  487  of the syringe S. 
     The flange  487  of the syringe S preferably includes holes  488  therein which are sized and spaced from each other a distance similar to a distance between prongs  465  on the retainer  460  associated with each station and near ends of the saddle. The prongs  465  can reside within the holes  488  so that the flange  487  of the syringe S is held securely to the infuser  410 . A side of the retainer  460  opposite the prongs  465  preferably includes a series of bores  467  therein which are spaced apart a distance similar to a distance between the prongs  465 . In such an arrangement, the prongs  465  can optionally reside within bores  467  of an adjacent separate infuser  410  (see for instance  FIG. 32 ) to allow two infusers  410  to be attached together. 
     The arm  440  and driver  450  of the infuser  410  are adapted to translate relative to remaining portions of the infuser  410  with the driver  450  able to engage with a proximal end of a plunger P of the syringe S to apply a force on the plunger P tending to drive fluid out of the outlet  485  of the syringe S. A passage through the retainer  460  allows the arm  440  to pass therethrough in a manner that allows translation of the arm  440  but resists rotation of the arm  440 . The arm  440  has a contour which matches the contour of this passage through the retainer  460  except at a section on the arm  440 , preferably near the piston  442 , where the arm  440  has a differing cross-section which facilitates rotation of the arm  440 . The particular geometry for such structures is depicted in  FIG. 23 . 
       FIGS. 24-28  reveal a series of steps associated with aligning the arm  440  and driver  450  of the infuser  410  with the plunger P of the syringe S and acting over time to efflux fluid out of the outlet  485  of the syringe S as the piston  442  is drawn into the chamber  420  of the infuser  410  to replace the vacuum contained therein.  FIG. 29  is an exploded parts view of that which is shown in  FIGS. 23-28 . 
     The piston  442  preferably has a specific configuration such as that depicted in  FIGS. 30 and 31 . The piston  442  is preferably fitted with a series of O-ring  444  type seals which are biased. With such a bias, air is allowed to pass more readily past the piston  442  and toward the arm  440  than past the piston  442  and away from the arm  440 . With such a biased configuration for the O-rings  444 , the piston  442  and associated arm  440  can be readily inserted into the chamber  420  during initial assembly without compressing air against the distal end of the housing. As the piston  442  is initially driven into the chamber  420 , air originally within the chamber  420  is able to pass the biased O-rings  444  to exit the chamber  420 . Once the piston  442  has been driven all the way to the distal end of the chamber  420 , the infuser  410  is then in a configuration ready for operation. When the piston  442  is later translated toward the proximal end of the chamber  420  and away from the distal end of the chamber  420 , air cannot pass the biased O-rings  444  so that a vacuum is drawn within the chamber  420  at the distal end thereof. Such a piston  442  with biased O-rings  444  eliminates the need for a port at the distal end of the chamber  420  for initial piston  442  positioning. 
     With particular reference to  FIG. 32 , an assembly is depicted which utilizes a pair of infusers  410  and a pair of syringes S. The two infusers  410  have been coupled together utilizing the clamps  430  and bosses  470  of the clamp  430  assemblies and the prongs  465  and bores  467  of the retainers  460 . Each infuser  410  is also coupled to a syringe S in the manner depicted in  FIGS. 23-28 . Such interconnection of the infusers  410  can be useful where more than one medication is to be infused simultaneously, so that separate syringes S are provided with separate medications. With the infusers  410  able to be coupled together, a single assembly is provided for delivery of two or more such medications. 
     Furthermore, and with reference to  FIGS. 23-28 , it can be seen that preferably at least two stations are provided on each clamp  430  assembly and each retainer  460 . Hence, two syringes S can be coupled to a single infuser  410 . According to one use of the infuser  410  of this invention, two syringes S loaded with medication can be coupled to separate stations on the infuser  410 . The infuser  410  can be set to begin infusing from one syringe S. When medication within the first syringe S has been entirely dispensed, the infuser  410  can be recharged by pulling the piston  442  and arm  440  out of the chamber  420  and rotating the arm so that the driver  450  is aligned with the second syringe S and then medication from the second syringe S can be dispensed. Thus, a potential for an overall singular assembly which has twice the capacity is facilitated. If three or more stations are provided on the clamp  430  assembly and retainer  460  of each infuser  410 , three or more syringes S can be included in such an overall assembly. With reference to  FIG. 33 , an infuser  510  is depicted which exhibits three such stations on a clamp  530  assembly and on a retainer  560  to illustrate how such a multi-station infuser  510  could be configured according to this embodiment. 
     While the infuser  410  is depicted with a vacuum chamber  420 , as an alternative a spring could be interposed between the arm  440  of the infuser  410  and the chamber  420  or infuser body replacing such a chamber  420 . In one embodiment this spring could be a helical compression spring located within the chamber and generally between the proximal side of the piston  442  and the retainer  460 . The chamber  420  could still be provided to allow the spring to operate within a controlled environment. Similarly, a helical tension spring could be interposed between a distal end of the arm  440  and a distal end of the chamber  420 , or other distal end of the infuser  410 . 
     With particular reference to  FIG. 36  details of a torsion power spring driven infuser  610  are described, according to an alternative embodiment. The torsion power spring driven infuser  610  includes a torsion spring  662  mounted about a central shaft which also acts as a spool  664  upon which a cable  660  can be gathered. This cable  660  extends from the shaft and associated spool  664  at a distal end to an arm  640  attachment point at a proximal end. The torsion power spring  662  exerts a rotative force upon the shaft tending to cause the shaft to rotate and for portions of the cable  660  to be gathered upon the spool  664 . In turn, this tension on the cable  660  causes an energizing tension force to be maintained on the arm  640  which in turn causes the driver  650  to act upon a plunger of the syringe S to drive the plunger into the syringe S and deliver fluid out of the syringe S. 
     The torsion power spring  662  is caused to have energy stored and the spring  662  to be wound by having the arm  640  and driver  650  pulled away from the torsion spring  662 . This energy can be stored on the spring  662  until needed. Then, when the driver  650  is coupled to a plunger of the syringe S and the arm  640  released from any engagement structures which lock the arm  640  in position, the arm  640  is caused to be drawn towards the central shaft of the torsion spring  662  to provide the infusion force. An infusion rate is provided which correlates with a spring force of the torsion spring  662  and to resistance to fluid flow associated with the syringe S and downstream structures such as microbore tubing, flow rate control elements and any friction built into the system. 
     The holes  488  in the flange  487  of the syringe S are preferably configured to match an arrangement of prongs  465  on the retainer  460  of the infuser  410 . Such coordination of holes  488  and prongs  465  can include the position of the holes  488  and prongs  465 , the number of holes  488  and prongs  465 , and the location of the holes  488  and prongs  465 . In addition to stabilizing the syringe S relative to the infuser  410 , such a particular configuration for the holes  488  and prongs  465  can act to coordinate syringes S of a particular style with infusers  410  of a particular style. For instance, infusers  410  having different rates of infusion and different amounts of force applied can be produced, such as by changing a diameter of the chamber  420 . Different medications have different desired rates of infusion. Syringes S preloaded with a medication having a desired rate of typical infusion could be configured with a hole  488  pattern on the flange  487  which would correspond with the prong  465  pattern on an infuser  410  which provides the desired infusion rate. Such coordination assists a user in matching a proper infuser  410  with the proper syringe S and medication. 
     While the holes  488  and prongs  465  are shown on the flange  487  and retainer  460  respectively, the prongs  465  could be provided on the flange  460  of the syringe S and holes  488  provided on the retainer  460 . While the prongs  465  and holes  488  are each shown with a circular cross-section they could have differing shapes which would not fit unless the proper syringe S is mated with the proper infuser  410 . Furthermore, even with standard syringes S and infusers  410  it is desirable that the holes  488  and prongs  465  act together to securely hold the flange  487  of the syringe S adjacent the infuser  410 . By matching configurations of the prongs  465  and holes  488 , a quality control feature is also provided in that syringes S and infusers  410  which have been manufactured to the desired quality standards interface together while syringes S and infusers  410  of differing quality standards and without the authorized prong  465  and hole  488  configuration would not match together, such that the quality expectations of the user can be met. 
     With reference to  FIG. 34 , details of an alternative embodiment gas driven infuser  710  are described. With this gas driven infuser  710 , the chamber is fitted with a piston  742  with associated arm. However, a distal end of the chamber  720  is not sealed and not configured to contain a vacuum. Rather, a proximal end of the chamber  720  is enclosed and has a feed line  762  associated therewith which leads to a control valve  764  to which a CO 2  gas cartridge  766  or other gas cartridge  766  can be attached. Typically this cartridge  766  is removably attached to the control valve  764 . One configuration could be similar to that utilized in paintball marker compressed CO 2  gas firearms. 
     The control valve  764  acts as a regulator which can selectively allow compressed gas to pass into the housing  720  through the feed line  762 . Through calibration and control of design details such as a friction of the piston  742  as it slides within the housing  720 , and an amount of resistance to flow associated with an outlet of the syringe S and/or downstream resistance such as within microbore tubing or other flow restriction devices, a rate at which the gas driven infuser  710  operates can be controlled. 
     As an alternative, a more active control can be utilized which causes the control valve  764  to open and close appropriately depending on whether a rate of infusion is faster or slower than a desired rate. Such a basic control system would keep track of a position of the plunger within the syringe S and keep track of time and increase or decrease openness of the control valve  764  depending on whether a sensed rate of infusion is faster or slower than a desired rate. 
     A bleed port would typically be built into the control valve  764  which would allow for the piston  742  to return to a proximal end of the housing  720 , such as after infusion of fluid from the syringe S has been completed and it is desired to reset the infuser  710  with a new loaded syringe S. One advantage of such a gas driven infuser  710  would be its ability to operate consistently in environments having different pressures, such as at different altitudes within Earth&#39;s atmosphere or potentially underwater or in space where pressures radically diverging from atmospheric pressure are experienced. 
     With particular reference to  FIG. 35  details of a motorized infuser  810  embodiment of this invention are described. With the motorized infuser  810 , a housing which would otherwise have been filled with gas (or containing a vacuum) is fitted with a motor  860 , such as at a distal end, with a rotating output shaft. This rotating output shaft is preferably coupled to an elongate threaded shaft  864 . A threaded nut  862  is configured to ride along this threaded shaft  864  with threads which mate with the threaded shaft  864  to cause the nut  862  to translate when the threaded shaft  864  rotates. An arm  840  of the infuser  810  is coupled to the nut  862  (with portions of this arm  840  cut away in  FIG. 15  to reveal details of the threaded shaft  864 ). 
     A driver  850  is coupled to the arm  840  and acts upon a plunger of the syringe S. Thus, when the motor  860  rotates, the threaded shaft  864  rotates, causing the nut  862  to translate and the arm  840  coupled to the nut  862  is also caused to translate so that the driver  850  acts on the plunger of the syringe S to infuse fluid from the syringe S. Typically, some form of guide is provided on the nut  862  to keep the nut  862  from rotating with the threaded shaft  864 , so that the nut  862  is required to translate when the threaded shaft  864  rotates. 
     A controller would be provided for the motor  860  which would keep track of a rate of rotation and match a rate of rotation and a rate of translation of the nut  862  to match a rate of infusion desired for the syringe S. Such a controller could be adjustable with inputs to allow medical professionals to set and adjust a rate of infusion associated with the motor  860 . The motor  860  would also require some form of power source to provide motive force for operation of the motor  860 . Such a power source could be batteries, a self contained power source such as fuel cells or solar panels, or could be an electric cord which can plug into available standard electric service. 
     Other forms of springs or resilient members could also be interposed between the arm  440  and other portions of the infuser  410  to provide the resistance force energizer of this invention to cause the driver  450  to apply forces on the plunger P of the syringe S. 
       FIG. 20  is a perspective view similar to  FIG. 7 , but with a dampening system  210  shown consisting of a dampening cylinder  292  attached to the infusion device body through a pair of supports  296  and a dampening rod  290  (terminating at a seal  294 ) attached to the force activator section  56  (force activator is equivalent to the arm and driver together). The dampening system  210  becomes active by allowing interaction of the cylinder  292  and rod  290  when the infusion device interacts with the syringe S during infusion and allows infuser incursion at a controlled, desired infusion rate. The dampening system  210  components (cylinder  292  and rod  290 ) may be reversed with respect to their location. 
     This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.