Abstract: A medical fluid injector includes: an air detection system for detecting air in the neck of the syringe; a hand-operated control lever for controlling movement of the injector ram; magnetic conductors for delivering magnetic fields from a power head face plate to an internal circuit board to permit detection of different face plates; a tilt sensor detecting the tilt angle of the power head to control the speed of motion brought about by the hand-operated control lever and to control an invertible display; and a monitor microcontroller for monitoring the behavior of the central processing unit to detect and react to error conditions.

Abstract: An improved injection device includes containing a pump and pump control circuitry, a handle with a needle for delivering a therapeutic agent to a patient, a cartridge holding the agent and a tube for delivering the agent from the cartridge to the handle. Preferably the cartridge is disposed in a cartridge holder coupled to the tube. A quick disconnect coupling is provided between the cartridge holder and the housing so that it can be easily mounted thereon. The housing further has a receptacle for receiving and storing the tip of the handle.

Abstract: A front-loading syringe which comprises a movable plunger for injecting liquid contrast media, is rotatably mountable on a front wall of an injector housing with an interference fit and in sealed relationship with respect thereto, with or without a pressure jacket, by a first-quick release mechanism. At the same time, the plunger is connected to an injector drive mechanism by a second readily releasable mechanism. During the mounting operation, a sensor reads injection information from an indicator device on the syringe and feeds it to an injector control. An audible-and-tactile indicating mechanism also is activated when the syringe is essentially in the desired mounted position. The syringe may include reinforcing ribs which also function as volumetric gradations, and liquid media presence-or-absence indicating dots which appear circular against a liquid media background and oval-shaped against an air background.

Abstract: A front-load syringe injector system includes a front-load injector apparatus having mounted on a front face thereof a detachably engageable adapter. A driving head is engaged with a drive mechanism of the injector and the driving head disengageably engages a plunger mounted in an angiographic syringe mounted on the adapter. At least one of the plunger and driving head and syringe elements interacts with the adapter to effect engagement and disengagement of the plunger and driving head and syringe with respect to one another.

Abstract: Device for the dosed release of an injectable product, comprising a housing, a retainer for a container, containing the product, in which a piston is displaceably accommodated, whose displacement in a feed direction causes the release of a product dose, a driven member including a driven rod which protruding into the container when the container is accommodated in the housing pushes the piston in the feed direction to release the product, at least one drive member engaging with the driven member, the driven member being displaced in the feed direction by the activation of the drive member, wherein the driven member contains a driven bush surrounding the driven rod, which driven bush engages into the drive member and is displaced together with the driven rod, and a rear wall--in relation to the feed direction--of the container protrudes at least during a release into an annulus formed between the driven rod and the driven bush.

Abstract: A medical fluid injector includes: an air detection system for detecting air in the neck of the syringe; a hand-operated control lever for controlling movement of the injector ram; magnetic conductors for delivering magnetic fields from a power head face plate to an internal circuit board to permit detection of different face plates; a tilt sensor detecting the tilt angle of the power head to control the speed of motion brought about by the hand-operated control lever and to control an invertible display; and a monitor microcontroller for monitoring the behavior of the central processing unit to detect and react to error conditions.

Abstract: A front-loading syringe which comprises a movable plunger for injecting liquid contrast media, is rotatably mountable on a front wall of an injector housing with an interference fit and in sealed relationship with respect thereto, with or without a pressure jacket, by a first-quick release mechanism. At the same time, the plunger is connected to an injector drive mechanism by a second readily releasable mechanism. During the mounting operation, a sensor reads injection information from an indicator device on the syringe and feeds it to an injector control. An audible-and-tactile indicating mechanism also is activated when the syringe is essentially in the desired mounted position. The syringe may include reinforcing ribs which also function as volumetric gradations, and liquid media presence-or-absence indicating dots which appear circular against a liquid media background and oval-shaped against an air background.

Abstract: A device for dosing medicinal fluids, in particular a feeding solution for enteral alimentation, has a pump unit (2) with a displacement element (15) and a drive unit (3) for the displacement element. The pump unit (2) can be separated from the drive unit (3) and is realized in the form of a non-reusable, disposable item. After the device has been used, the pump unit is simply replaced with a new pump unit, so that it is unnecessary to clean the parts of the dosing device that carry the fluid.

Abstract: An injector head for medical use is provided with a position plate serving as both the position plate and a nut, placed at a rear end portion of a plunger, as well as a screw axis engaging with the position plate. A mechanical stopper which can slide only in a direction of an axis of the plunger is provided to the plunger. A female thread is formed on the surface of the mechanical stopper. A main body portion is provided which accommodates the mechanical stopper, the plunger, and the position plate and has a male thread formed on its inner surface and screwed together with the female thread. By utilizing this structure, an injector head for medical use can be provided which is scaled down and simplified while keeping its mechanical safety mechanism.

Abstract: The pressure jacket systems of the invention are used to permit the front loading and removal of a syringe from an injector and include a first jacket segment and a second jacket segment surrounding the exterior surface of the syringe, interior surfaces comformable to the exterior surface of the syringe, a mechanism which allows movement of the first jacket segment in relation to the second jacket segment to permit insertion and removal of the syringe from the pressure jacket, and a mechanism for securing the first and second jacket segments in a fixed relationship upon insertion of the syringe.

Abstract: The present invention relates to a drug delivery device wherein a dose to be apportioned from a cartridge is set by changing the relative position of co-operating dose setting elements (3, 5) and is injected by pressing a button (5) until this button abuts a stop (6). By operation of count up (7) or count down (8) buttons the dose is set and read into an electronic circuit (9) comprising a microprocessor and the dose setting movement of the dose setting elements relative to each other is performed by a motor (11) controlled by the circuit in accordance with the read in dose. The set dose is shown on a display (10). The motor (11) is further controlled to perform certain movements of the piston rod (3) so as retraction of this rod when a cartridge (1) is going to be changed an advancing of the piston rod to abutment with the piston (2) after the cartridge has been changed and further to advance this piston to expel air from the cartridge.

Abstract: A medical fluid injector includes: an air detection system for detecting air in the neck of the syringe; a hand-operated control lever for controlling movement of the injector ram; magnetic conductors for delivering magnetic fields from a power head face plate to an internal circuit board to permit detection of different face plates; a tilt sensor detecting the tilt angle of the power head to control the speed of motion brought about by the hand-operated control lever and to control an invertible display; and a monitor microcontroller for monitoring the behavior of the central processing unit to detect and react to error conditions.

Abstract: The pressure jacket systems of the invention are used to permit the front loading and removal of a syringe from an injector and include a first jacket segment and a second jacket segment surrounding the exterior surface of the syringe, interior surfaces comformable to the exterior surface of the syringe, a mechanism which allows movement of the first jacket segment in relation to the second jacket segment to permit insertion and removal of the syringe from the pressure jacket, and a mechanism for securing the first and second jacket segments in a fixed relationship upon insertion of the syringe.

Abstract: A medical fluid injector includes: an air detection system for detecting air in the neck of the syringe; a hand-operated control lever for controlling movement of the injector ram; magnetic conductors for delivering magnetic fields from a power head face plate to an internal circuit board to permit detection of different face plates; a tilt sensor detecting the tilt angle of the power head to control the speed of motion brought about by the hand-operated control lever and to control an invertible display; and a monitor microcontroller for monitoring the behavior of the central processing unit to detect and react to error conditions.

Abstract: The pressure jacket systems of the invention are used to permit the front loading and removal of a syringe from an injector and include a first jacket segment and a second jacket segment surrounding the exterior surface of the syringe, interior surfaces comformable to the exterior surface of the syringe, a mechanism which allows movement of the first jacket segment in relation to the second jacket segment to permit insertion and removal of the syringe from the pressure jacket, and a mechanism for securing the first and second jacket segments in a fixed relationship upon insertion of the syringe.

Abstract: The invention presents a syringe for injecting a dose of an agent and for electrically indicating the size of the dose. The syringe has a barrel for holding the dose and a plunger for expelling the dose from the barrel. The barrel has a conducting rim that contacts a surface of the plunger lined with electrical contact points. The position of the plunger inside the barrel determines which one of the contact points contacts the conducting rim. Each contact point is electrically connected to a different output terminal located on the syringe cap. The conducting rim is electrically connected to a voltage input terminal located on the syringe cap. A voltage applied to the input terminal causes an electric current to flow through a circuit comprising the conducting rim, the one contact point contacting the conducting rim, and the one output terminal connected to that one contact point.

Abstract: Method for the controlled injection of a liquid in a tube by means of a peristaltic type pump actuated by a rotary d.c. motor (12) controlled by a control unit (10) such as a microprocessor, wherein an optical encoder (18) sends pulses to said control unit (10) during the intermittent operation of the motor. The method comprises operating the motor for period corresponding to a number of pulses equal to a set value. For each operating phase of the motor (12), equal to a predetermined number of pulses, the set value is reduced by the number of pulses transmitted during the preceding deceleration phase when the power supply is interrupted. The resulting error in the level of the volume of liquid to be injected thus remains approximately constant for the entire length of the injection period. The method according to the invention may be advantageously used in a programmable portable infusion system.

Abstract: An animal fluid injector, replaceable syringe and method of replacement of the syringe in the injector are provided in which the syringe is loadable and unloadable into and from the injector through the open front end of a pressure jacket of the injector, thereby permitting replacement without retraction of the syringe plunger drive or disconnection of the injection tubing. The syringe is provided with a pressure restraining front end, such as an integral or removable cap with structure such as threads that lock the syringe to the front end of the jacket by mating with threads on the jacket. A mechanism in the injector, which includes, for example, a key on cam ring operated by a lever with one hand of an operator, interacts with structure such as symmetrically spaced notches on the back end of the syringe to, for example, rotate the syringe and simultaneously translate or rotate a coupling on the syringe plunger into and out of engagement with the plunger drive in the injector.

Abstract: A method and device for electrically measuring and recording injection syringe doses. The device has a voltage generator for applying a voltage to an input terminal of a syringe. The device also has a measuring instrument for measuring an electrical response from the syringe. The electrical response results from the voltage and indicates the size of the dose in the syringe. An electronic memory records the measurement of the electrical response so that there is an electronic record of the dose injected. A data port is connected to the electronic memory so that the dose records may be transmitted to a host computer.

Abstract: A releasably attachable manual dispensing aid is operable with a syringe having a syringe body and a syringe plunger that is movable within the syringe body. The dispensing aid includes a dispensing aid body that is releasably attachable to the syringe body. The dispensing aid further includes a dispensing aid plunger that is attachable to the syringe plunger, and has a slide that is slidable within the dispensing aid body. A fine adjustment, bottom stop, Chaney stop, and/or drag brake for the slide are optionally provided. An electronic linear position measuring device has a first portion fixed to the dispensing aid body and a second portion fixed to the dispensing aid plunger. Optionally, the dispensing aid includes a microprocessor that receives as inputs a calibration value for a particular syringe and the position signal, and determines as an output signal the true volume of liquid displaced by the syringe plunger movement.

Abstract: A medication delivery device, such as a pen-type injector, jet injector, medication pump, inhaler, spray or the like has a microprocessor coupled to the device that records the date, the time, and the amount of each medication administration. The microprocessor may also be coupled to a display to indicate the amount of medication to be administered. The medication delivery device can also be coupled with a blood characteristic monitor to analyze characteristics of the blood. This provides a single, all-in-one device that performs a variety of functions, and requires only a minimum of space. The medication delivery device may also use a disposable needle that substantially eliminates or reduces bleeding from an opening in the skin at the injection site.

Abstract: A cylinder pump having a controllable piston/drive detachment is disclosed that can engage or disengage a piston rod using a solenoid. Most any type of drive can be used. The cylinder pump could have one or more cylinders. Each cylinder and piston rod has quick connect and disconnect mountings. The cylinder pump could be a syringe pump or drive.

Abstract: A plunger driver system which engages a plurality of different sizes of syringes. A pushing surface includes a detector to determine syringe plunger presence. In the event that the plunger is not present and the pump is operating, a processor provides an alarm and may stop the pump motor. Arms retain the plunger flange in a fixed position in relation to the plunger driver. The arms have anti-siphon flanges to prevent too rapid movement of the plunger into the syringe barrel. A shelf for opposing downward movement of the syringe plunger and a ramp to guide the syringe plunger into position in relation to the plunger driver are included in the plunger driver. A cradle for containing all sizes of syringe barrels yet aligning the syringes with the plunger driver is included with a clamp to hold the syringe barrel in position in the cradle. The detector button includes a bevel at its top edge to facilitate loading the plunger in the driver.

Abstract: A medical injection device, such as a pen-type injector has a microprocessor coupled to the injector that records the date, the time, and the amount of each injection. The microprocessor may also be coupled to a display to indicate the amount of medication to be injected. The medical injection device can also be coupled with a blood characteristic monitor to analyze characteristics of the blood. This provides a single, all-in-one device that performs a variety of functions, and requires only a minimum of space. The medical injection device may also use a disposable needle that substantially eliminates or reduces bleeding from an opening in the skin at the injection site.

Abstract: The adapters of the present invention are used for releasably attaching syringes of various types having a body, a plunger reciprocally mounted therein, and a flange near the rear end of the syringe body, to a front-loading injector head. In a preferred embodiment, the adapter includes a syringe carrier having a front end, a rear end, and syringe retaining channel located between the carrier front and rear ends for engaging at least a portion of the syringe flange; mounting flanges near the carrier rear end for releasably mounting the carrier in a desired position relative to the front wall of the injector head; a follower reciprocally mounted within the carrier having a front end engagable with the syringe plunger when the syringe is installed in the carrier; and a drive head opening communicating with a pair of drive head slots positioned proximate to the rear end of the follower for releasably mounting the follower in a desired position relative to the drive head of the injector head.

Abstract: This invention relates generally to the field of Magnetic Resonance Imaging (MRI) systems for generating diagnostic images of a patient's internal organs and more particularly, this invention relates to improved MRI systems with decreased interference between the magnetic field used for producing diagnostic images and the magnetic fields generated by the electric motors used for driving the pistons of the contrast media injectors. Additionally, the system employs an improved communication link between an externally located system controller and the injection head control unit located within the electromagnetic isolation barrier which defines the magnetic imaging room.

Abstract: An animal fluid injector, replaceable syringe and method of replacement of the syringe in the injector are provided in which the syringe is loadable and unloadable into and from the injector through the open front end of a pressure jacket of the injector, thereby permitting replacement without retraction of the syringe plunger drive or disconnection of the injection tubing. The syringe is provided with a pressure restraining front end, such as an integral or removable cap with structure such as threads that lock the syringe to the front end of the jacket by mating with threads on the jacket. A mechanism in the injector, which includes, for example, a key on cam ring operated by a lever with one hand of an operator, interacts with structure such asymmetrically spaced notches on the back end of the syringe to, for example, rotate the syringe and simultaneously translate or rotate a coupling on the syringe plunger into and out of engagement with the plunger drive in the injector.

Abstract: An injector for delivering fluid to a preselected internal target tissue while avoiding fluid exposure to surface tissue. A needle housing assembly is concealed within a cartridge having a puncturable end cap and an ampule is also disposed within the cartridge separate from the needle housing assembly. The cartridge has a cylindrical bore which widens at one end such that the needle housing assembly which has walls while located within the narrower portion of the cylindrical bore prevents the ampule from being punctured by a hollow injection needle supported by the needle housing assembly. When the ampule is propelled toward the needle housing assembly with a plunger, the needle housing assembly enters the widened portion of the cylindrical bore, allowing its walls to be separated such that the hollow injection needle extends into the ampule allowing the fluid to be delivered from the ampule through the hollow injection needle to the internal target tissue.

Abstract: Providing fluid to an internal delivery site of a patient includes moving the fluid from a fluid reservoir through a conduit and through a delivery device at the delivery site while maintaining the fluid at a predetermined pressure. The delivery device may comprise an inflatable balloon with apertures formed in its periphery for directing the fluid into the vessel walls. Pressurized fluid is provided through the apertures of the balloon to the vessel wall. The pressure is automatically controlled to avoid both pressure spikes and unacceptable deflation of the balloon during administration of the fluid. A further feature includes comparing the pressure with the volume infused and in the event that pressure decreases while the volume infused increases beyond certain limits, the delivery of the fluid is stopped. Further features include a timer for limiting the inflation time of the delivery device and a volume detector for controlling the amount of fluid delivered.

Abstract: High viscosity materials are dispensed or aspirated by an assembly of cartridges having plungers reciprocally mounted within them. A device for translating rotary motion into linear motion is connected to the output shaft of a small electric motor so that operation of the motor effects linear movement of the plungers. The assembly replaces hydraulic and pneumatic systems and enables better control of the dispensing or aspirating process. In a first embodiment, a single cartridge dispenses a high viscosity material. In additional embodiments, plural cartridges are employed. In the final embodiments, the apparatus is equipped with a suitable assembly of one-way valves and other auxiliary equipment so that it can be used to perform liposuction or aspiration procedures and irrigation of surgical sites.

Abstract: An electromechanical injection device for medical and veterinary use comprises a frame (1) having the shape of a pistol provided with a stock (2) and bearing a movable carriage (3) that supports a removable syringe (4) having a needle (5) and a piston (6). A first motor (7) actuates a pusher (8) which acts against the piston (6) of the syringe (4). A cradle (9) is carried by the frame (1) and supports the syringe (4) on the movable carriage (3). A second motor (12) actuates the movable carriage (3). The forward portion of the frame has a stabilizing sight (10) for application to the skin which guides and predetermines the degree of penetration of the needle (5). An adjustment wheel (11) permits adjusting the position of the sight (10) to adjust the depth of penetration of the needle (5). A trigger (18) actuates the motors (7, 12). The second motor (12 ) is fixed to the frame (1) and has a rotatable axle (30) and a first cam (29) on that axle.

Abstract: An animal fluid injector, replaceable syringe and method of replacement of the syringe in the injector are provided in which the syringe is loadable and unloadable into and from the injector through the open front end of a pressure jacket of the injector, thereby permitting replacement without retraction of the syringe plunger drive or disconnection of the injection tubing. The syringe is provided with a pressure restraining front end, such as an integral or removable cap with structure such as threads that lock the syringe to the front end of the jacket by mating with threads on the jacket. A mechanism in the injector, which includes, for example, a key on cam ring operated by a lever with one hand of an operator, interacts with structure such asymmetrically spaced notches on the back end of the syringe to, for example, rotate the syringe and simultaneously translate or rotate a coupling on the syringe plunger into and out of engagement with the plunger drive in the injector.

Abstract: A belt driven infusion pump for emptying the contents of a syringe is disclosed. The pump includes a syringe pusher including an antisiphon catch and a pressure detector which is used for detecting occlusions or the end of infusion. A syringe clamp for locking a syringe in place is also provided. The syringe clamp is spring loaded and lockable. A syringe position detector is provided to ensure the proper placement of the syringe prior to and during pumping. A control knob is provided on the face of the pump for controlling both the locking of the syringe barrel clamp and the coupling of the drive belt with a d.c. motor. The pump includes a housing having an elongated slot through which the syringe pusher is connected to the drive belt. A sealing band is connected to the syringe pusher and is moveable with the syringe pusher for sealing the slot against moisture or other contaminants.

Abstract: A belt driven infusion pump for emptying the contents of a syringe is disclosed. The pump includes a syringe pusher including an antisiphon catch and a pressure detector which is used for detecting occlusions or the end of infusion. A syringe clamp for locking a syringe in place is also provided. The syringe clamp is spring-loaded and lockable. A syringe position detector is provided to ensure the proper placement of the syringe prior to and during pumping. A control knob is provided on the face of the pump for controlling both the locking of the syringe barrel clamp and the coupling of the drive belt with a d.c. motor. The pump includes a housing having an elongated slot through which the syringe pusher is connected to the drive belt. A sealing band is connected to the syringe pusher and is moveable with the syringe pusher for sealing the slot against moisture or other contaminants.

Abstract: A belt driven infusion pump for emptying the contents of a syringe is disclosed. The pump includes a syringe pusher including an anti-siphon catch and a pressure detector which is used for detecting occlusions or the end of infusion. A syringe clamp for locking a syringe in place is also provided. The syringe clamp is spring-loaded and lockable. A syringe position detector is provided to ensure the proper placement of the syringe prior to and during pumping. A control knob is provided on the face of the pump for controlling both the locking of the syringe barrel clamp and the coupling of the drive belt with a d.c. motor. The pump includes a housing having an elongated slot through which the syringe pusher is connected to the drive belt. A sealing band is connected to the syringe pusher and is moveable with the syringe pusher for sealing the slot against moisture or other contaminants.

Abstract: An infusion pump, suitable for medical applications, has a movable carriage which is arranged gradually to depress the plunger of a syringe. The carriage moves along a fixed rod at a rate determined by the rotation of a lead screw. Any excess pressure in the infusion line produces a back-pressure on the plunger which causes an axial force to be exerted on the carriage and thus on the lead screw. When this force exceeds a predetermined value, indicative of an occlusion of he infusion line, the lead screw will move axially so compressing a spring and causing a clutch to become decoupled, causing infusion to cease and an alarm to sound.

Abstract: A syringe of relatively simple construction which is capable of both accurate and reproducible sample volume withdrawals, including volumes of 1.0 .mu.l or less, is provided. The syringe drive mechanism is preferably adapted for use in a liquid sampling apparatus and includes a threaded lead screw, a drive for rotating the screw, and a syringe having a plunger for withdrawing a liquid sample. The plunger is mechanically connected to the rotating lead screw by a nut threaded onto the screw and a slider mechanism associated with the nut which also is secured to the plunger. The nut is designed so that lateral misalignment of the drive screw does not affect the precise linear movement of the slider mechanism, and consequently, the plunger. This provides a mechanism which is less expensive to assemble and align properly, but which has a high degree of accuracy and reproducibility.

Abstract: A syringe plunger position detection and alarm system continuously determines the position of a syringe plunger and provides near end of travel and end of travel alarms. Plunger movement is also monitored and if movement is less than a calculated amount, an alarm is provided. A variety of syringes of different sizes is usable. A potentiometer is mounted along the line of travel of the screw drive mechanism and a marker is mounted to extend from the screw mechanism to the potentiometer to force an internal contact in the potentiometer. The voltage provided by this internal contact is analyzed by the process to derive absolute and relative position of the plunger. The end of travel position of each plunger is stored in processor memory and from the operator input rate of infusion, the characteristic curve of the potentiometer also stored in memory, the plunger displacement of the syringe, and the time of the near end of travel alarm, the voltage of the near end of travel position is calculated.

Abstract: A belt driven infusion pump for emptying the contents of a syringe is disclosed. The pump includes a syringe pusher including an antisiphon catch and a pressure detector which is used for detecting occlusions or the end of infusion. A syringe clamp for locking a syringe in place is also provided. The syringe clamp is spring-loaded and lockable. A syringe position detector is provided to ensure the proper placement of the syringe prior to and during pumping. A control knob is provided on the face of the pump for controlling both the locking of the syringe barrel clamp and the coupling of the drive belt with a d.c. motor. The pump includes a housing having an elongated slot through which the syringe pusher is connected to the drive belt. A sealing band is connected to the syringe pusher and is moveable with the syringe pusher for sealing the slot against moisture or other contaminants.

Abstract: A system for simultaneously filling multiple reservoirs of an IV delivery system comprises a support frame, port positioners on the support frame for positioning a plurality of fill ports of a multiple chamber reservoir, a plurality of injection pumps for injecting a predetermined amount of a fluid, coupling devices for coupling the injection pumps to a fill port of a reservoir, and an actuator for simultaneously coupling the couplers to the fill ports and filling said reservoirs with a predetermined amount of a fluid.

Abstract: A syringe pump in which a movable member is attached to a frame so as to be movable forward and backward, a transmission roller, transmission gear and speed increasing gear are attached to the movable member, the drive force of a motor is transmitted to the transmission roller through a timing belt, and a clutch mechanism including a rotating member with teeth and a rotation preventing member with teeth engaged with the former teeth is provided whereby the drive force of the transmission gear is transmitted to the rotating member through a guide member comprising a timing belt. The movable member moves along the guide member in the state where the teeth of the rotating member and rotation preventing member are engaged with each other.

Abstract: This invention relates to a syringe-pusher device for ambulatory treatment, automatically delivering in a constant time compatible with the circadian rhythms, a fixed number of elementary volumes varying as a function of the prior filling volume of the syringe used by the operator. Said volume generally corresponding to the daily dose of drug can be directly read on the graduations on the syringe. A sound alarm is set off in the event of an impediment to the flow of the fluid as well as in the event of the untimely injection of elementary volume outside the set program.

Abstract: Automatic engagement of a lead screw with a lead screw drive mechanism. A plunger driver used to move the plunger of a syringe is connected to the screw drive mechanism. A first detector provides a plunger signal indicating the presence of a syringe plunger in the plunger driver and a second detector provides a thread engagement signal indicating engagement or disengagement of the lead screw drive mechanism with the lead screw. The thread engagement detector monitors movement of a rigid linkage at the screw drive mechanism which has a nonlinear characteristic curve. In the case where the plunger signal indicates the presence of a plunger and the thread engagement signal indicates engagement of the drive mechanism with the lead screw, the lead screw is rotated in a forward direction to remove the thread clearance.

Abstract: A half-nut block containing a threaded bore and a larger, overlapping, unthreaded bore is engaged with a lead screw. The larger bore overlaps the threaded bore so that effectively a half-nut results. The half-nut comprises a face having an acute angle in relation to the lead screw and this angled face contacts the inside of a bearing block within which the half-nut is mounted. The bearing block is slidably mounted on a C-tube which is mounted around and extends along a predetermined length of the lead screw. Also mounted on the C-tube is an arm for transmitting the linear motion of the bearing block to a remote point such as the plunger of a syringe. The arm is coupled to the bearing block at points selected so that transmission to the arm of any wobbling of the bearing block is reduced. The arm includes a lever which engages a cam formed on the half-nut to force the half nut to disengage from the lead screw when the arm is to be moved to a new location on the lead screw.

Abstract: An automatic syringe drive assembly and disposable heat exchanger cassette are used in combination to provide an improved thermodilution technique and apparatus. The automatic syringe drive assembly includes replaceable connecting rods on a slider crank mechanism which permit easy and accurate adjustment of the syringe injection volume. The drive assembly supports as insulated syringe for use in making the injection. The heat exchanger cassette includes a heat transfer plate and a thermoformed plastic labyrinth adhesively connected and used in combination with a thermoelectric chiller to provide a cold bolus of injectate.

Abstract: A drug infusion pump having a drive system including a drive motor (49), a worm gear (53) on the output shaft of said motor, a worm wheel (55) meshing with said worm gear (53) and constructed to drive an output reduction gear (60) and clutch means (62) associated with said output gear (60) for disengaging drive to a drive head (61) engaged by a drive belt (83) which is permanently connected to a syringe actuator (7) to cause controlled infusion of the contents of a syringe under the control of a central control system including a microprocessor (20) and programmable memory means (21 and 23) which determine the manner in which the infusion is performed. A syringe clamping arm (5) is associated with a potentiometer (24) which provides to the controller diameter information regarding the syringe. The programmable memory means (23) includes data relating to one or more standard syringe sizes to enable automatic operation on insertion of a standard syringe.

Abstract: A filling device for filling an injection syringe is provided which enables the user to count the intake dosage by means of a sound indicator which may be mechanical, electrical or an electronic sound device. The filling device includes a moveable syringe holder to which is attached a removable syringe that is connectable to a medicinal bottle. The filling device mounts a gear which is moveable one notch at a time to actuate a linear gear to which the syringe is mounted. The device is connected to a microprocessor controlled voice chip device to obtain a suitable voice readout indicating the amount of liquid medicinal uptake by the syringe.

Abstract: An infusion pump has a housing for receipt of a syringe, a motor to drive the plunger of the syringe to expel a medicant within the syringe, a computer for controlling the motor and a place to mount the syringe. A bar code reader is mounted adjacent the syringe and the syringe has a pharmacist-applied bar code that programs the computer with the data for the dispensing of the medicant.

Abstract: An angiographic injector has an injector portion which includes a rotating turret for housing two angiographic syringes in readiness for injection. The injector further employs a driving mechanism for connecting with and controlling the movement of a syringe plunger once one of the syringes is in place for injection. Through the use of guide means on each syringe and corresponding alignment means on a pressure jacket, the syringe is alignably and securely mounted within the pressure jacket on the rotating turret. Each syringe plunger is releasably connected to the driving mechanism for an injection operation, and released from the driving mechanism when the injection operation has been completed, such that the driving mechanism can be withdrawn from the syringe relative to the plunger without drawing body fluid of a patient into the syringe. Various types of plunger release mechanisms for this purpose are disclosed.The questions raised in reexamination request No. 90/003,918 filed Aug.

Abstract: This invention relates generally to the field of Magnetic Resonance Imaging (MRI) systems for generating diagnostic images of a patient's internal organs and more particularly, this invention relates to improved MRI systems with decreased interference between the magnetic field used for producing diagnostic images and the magnetic fields generated by the electric motors used for driving the pistons of the contrast media injectors. Additionally, the system employs an improved communication link between an externally located system controller and the injection head control unit located within the electromagnetic isolation barrier which defines the magnetic imaging room.