Abstract: An extra-capillary fluid cycling unit for maintaining and cycling fluid volumes in a cell culture chamber includes a housing and a first flexible reservoir extra-capillary fluid reservoir disposed in the housing. The extra-capillary fluid reservoir is in fluid communication with a cell culture chamber. A second flexible reservoir is also located in the housing, the second flexible reservoir being in fluid communication with a pressure source. A sensor plate is movably disposed in the housing between the extra-capillary reservoir and the second reservoir, wherein the second reservoir is pressurized to move the sensor plate in relation to the extra-capillary reservoir to cause fluid cycling and maintain fluid volumes in the cell growth chamber.

Abstract: A peristaltic pump for dispensing liquid is described and includes a front housing and a rear housing snap-fitted together to define a chamber having a recessed area and a rotor confined therein, a plurality of rollers mounted in the rotor, and a flexible tube compressed at equally spaced intervals by the plurality of rollers. The rotor undergoes a gradual increase in torque as a benefit of the recessed area, rather than an immediate high-torque load at the start of each pump cycle. Further, the pump is resistant to constant torques and vibrations caused by a machine to which it is attached so that the pump does not become loose and fall apart.

Abstract: Apparatus for the treatment of the blood, comprising at least one pump (25, 26, 27), matchable with a corresponding portion of tube (35, 36, 37) supported by a cartridge or module (3) which is associated to the apparatus (1), characterized in that it comprises a pump capable of reducing the pressure inside the chamber defined by the association of the cartridge (3) to the apparatus (1).

Abstract: A pump arrangement includes a pump having a pump inlet and a pump outlet, and a safety valve arranged between the pump outlet and an outlet of the pump arrangement and having a valve seat and a valve lid. The valve seat, the pump outlet and the pump inlet are patterned in a first surface of a first integrated part of the pump arrangement, whereas the valve lid is formed in a second integrated part of the pump arrangement. An inlet of the pump arrangement and a fluid region fluidically connected thereto are formed in a third part of the pump arrangement. The second integrated part is arranged between the first integrated part and the third part of the pump arrangement such that a pressure in the fluid region has a closing effect on the safety valve, the pump inlet and the inlet of the pump arrangement being connected fluidically.

Abstract: A pump producing peristaltic pumping action by sequentially occluding a tube between staggered curved surfaces. The pump includes a pump frame with a platen. The platen has an irregular surface forming a plurality of curved end surfaces. The irregular surfaces of the platen operatively interact with a pressure plate assembly having a plurality of pressure plates. The pressure plates are configured for translational motion. In operation the pressure plates are spaced one from another such that each one includes an end curved surface extending generally toward complementary staggered curved surfaces on the platen. Pumping is accomplished via a tube sandwiched between the platen and the pressure plate assembly. A drive operatively associated with the pump frame and pressure plate assembly drives the pressure plates in a wave sequence so as to sequentially occlude portions of the tube between staggered curved surfaces so as to promote a peristaltic pumping action within the tube.

Abstract: According to the present invention, a dialysis fluid pump comprises: a housing having an accommodating space formed therein; a dialysis fluid supply tube and a dialysis fluid recovery tube, at least a portion of each of which is accommodated in the accommodating space; a cam rotatably installed in the accommodating space; a motor for rotating the cam; and a first backflow pressure preventer and a second backflow pressure preventer adapted to be mobile in the accommodating space and be pushed by the cam. The dialysis fluid supply tube is made of a flexible material which can be contracted or relaxed, and one end thereof is connected to a dialysis fluid supply tank and the other end thereof is connected to a hemodialysis filter. The dialysis fluid recovery tube is made of a flexible material which can be contracted or relaxed, and one end thereof is connected to a dialysis fluid recovery tank and the other end thereof connected to the hemodialysis filter.

Abstract: An extracorporeal blood therapy control unit housing has a first and second manually mounted panels and spring loaded components configured for releasably engaging and tensioning the said panels against a side of said housing. The first and second panels have arch-shaped tubing segments mounted on the interior side of said respective panels. Each of the tubing segments are held in operational engagement with a different peristaltic pump rotor by the panel engaging and tensioning components.

Abstract: A two-stage membrane pump having a first pump head and a second pump head is provided. The pump heads are typically crank operated with a camshaft set up such that one pump head is in exhaust mode and the other in inlet mode, and vice-versa, during operation. The membrane and the inlet and outlet valves of the pump heads are designed to work together, along with each pump head working synchronously such that the inlet of the second pump head and exhaust of the first pump head are sealed by the actions of the two membranes. As a result an inlet valve in the second pump head is not needed. The costs of such a pump are thereby reduced while increasing the reliability of the two-stage pump.

Abstract: Disclosed are improved methods and apparatus for radiolabeling, particularly methods and apparatus for large scale in-line radiolabeling of products, such as proteins and antibodies.

Abstract: Disclosed are devices and methods for the control of body fluid flow in the extracorporeal treatment of body fluid. Body fluid flow through on of a body fluid flow circuit 10, 50, 60 100, or 250 is controlled by alternatingly applying vacuum pressure and positive pressure to the circuit through a pumping chamber 30, 51, 66, 102, or 200 coordinated with flow control valves 40, 42, 44, 62, 114, 116, 118, and 120 to effect a net downstream flow of body fluid through the circuit.

Abstract: The present invention provides an addressable multi-channel peristaltic pump. According to the invention, this pump design allows for selection and operation of one or more pump heads on a drive shaft, while locking other non-selected pump heads in a stationary position. It is possible to operate the multi-channel pump using a limited number of motors, preferably two motors: a selector motor and a dispense motor. Thus, the pump provides for pumping or dispensing of one or more fluids without the need for multiple pumps. Likewise, compared with typical single motor multi-channel systems, where all pump heads on the drive shaft must rotate at the same time, the present invention provides for selective dispensing of one or more fluids. The pumps of the present invention are suitable for any multiple fluid transfer application, including in automated multi-channel reagent dispensing systems, such as nucleic acid purification systems.

Abstract: A two-stage membrane pump having a first pump head and a second pump head is provided. The pump heads are typically crank operated with a camshaft set up such that one pump head is in exhaust mode and the other in inlet mode, and vice-versa, during operation. The membrane and the inlet and outlet valves of the pump heads are designed to work together, along with each pump head working synchronously such that the inlet of the second pump head and exhaust of the first pump head are sealed by the actions of the two membranes. As a result an inlet valve in the second pump head is not needed. The costs of such a pump are thereby reduced while increasing the reliability of the two-stage pump.

Abstract: A centrifugal fluid separation system is disclosed for centrifugally separating a composite fluid into components thereof. This centrifugal separation system includes at least a centrifugal rotor which has a composite fluid containment area, a fluid flow channel/tubing and at least one separated component collection area defined therein. A composite fluid to be separated is delivered to the fluid containment area where under centrifugal forces the composite fluid is separated into components and then from which a component travels through an outlet channel to a respective separated component fluids flowing therethrough. A centrally disposed pump is also provided to move the separated component(s) to the collection area(s). Optical sensing of the interface of the separated fluid components may be used with a clamp to stop flow. A disposable bag and tubing system is also disclosed for use with reusable rotor devices.

Abstract: An air compressor formed of a plurality of collapsible members engaged between opposing rotating side members. The collapsible members alternate between a collapsed state and enlarged state during rotation around the side members which are engaged to polygonal segments of a generally circular rotating frame. Air compressed in each of said collapsible members during rotation toward the collapsed state is communicated to a reservoir in sealed communication with each of the plurality of bellowed members. The reservoir acts to hold-compressed air for use for powering air powered devices.

Abstract: A peristaltic pump for pumping fluids through a flexible tube has a pump body, a support structure, a tube retaining mechanism and a linkage mechanism. Locating features make sure that the support structure is at a fixed location with respect to the pump body when the pump is in the closed position. The support structure controls movement of the retaining mechanism. The linkage mechanism applies the necessary force to move the support structure so that the pump is moved from an open position to a closed position.

Abstract: Disclosed are devices and methods for the control of body fluid flow in the extracorporeal treatment of body fluid. Body fluid flow through on of a body fluid flow circuit (10, 50, 60, 100 or 250) is controlled by alternating applying vacuum pressure and positive pressure to the circuit through a pumping chamber (30, 51, 66, 102, or 200) coordinated with flow control valves (40, 42, 44, 62, 114, 116, 118, and 120) to effect a net downstream flow of body fluid through the circuit.

Abstract: An air compressor formed of a plurality of collapsible members engaged between opposing rotating side members. The collapsible members alternate between a collapsed state and enlarged state during rotation around the side members which are engaged to polygonal segments of a generally circular rotating frame. Air compressed in each of said collapsible members during rotation toward the collapsed state is communicated to a reservoir in sealed communication with each of the plurality of bellowed members. The reservoir acts to hold-compressed air for use for powering air powered devices.

Abstract: The hose pump comprises an eccentric drive with numerous eccentric discs (21) fastened to a shaft (20). Each eccentric disc (21) drives a crank drive (24) having a connecting rod (25). At the end of the connecting rod (25), a pump finger (11) is borne for compressing a pump hose (10). A sealing diaphragm (27) is disposed between the eccentric drive and the pump hose (10) for preventing liquid from intruding into the interior of the housing (16). The connecting rod (25) sealingly passes through the sealing diaphragm (27). The sealing diaphragm (27) comprises lateral folds (31) so that it does not exert any substantial forces upon the crank drive (24). The hose pump has a low power consumption and permits a small structure.

Abstract: An occlusion for use in a peristaltic pump includes independently movable occlusion fingers. The fingers are integrally formed as a single unitary body.

Abstract: A liquid cooling system utilizing minimal size and volume enclosures, air pockets, compressible objects, and flexible objects is provided to protect against expansion of water-based solutions when frozen. In such a system, pipes, pumps, and heat exchangers are designed to prevent cracking of their enclosures and chambers. Also described are methods of preventing cracking in a liquid cooling system. In all these cases, the system must be designed to tolerate expansion when water is frozen.

Abstract: The method of and the apparatus for the formation of a high-speed fluid or slurry jets of a desired geometry are invented. According to the present invention a fluid or slurry jet is formed by the expelling of a compressed fluid via a slot formed by two attached plates separated by the insertion. The shape of the slot is determined by the forms of the plates and the insertion. This shape is also determined by the deformation of the plates and the insertion by the external forces applied to the plates, for example by the fasteners connecting the plates.

Abstract: A fluid delivery system is provided having a disposable fluid reservoir that is integral with, and supported by, a pump housing. A peristaltic pump head is mounted within the pump housing. A length of flexible tubing is operatively engaged by the peristaltic pump, and includes a first end arranged in flow communication with the fluid reservoir and an accessible second end. A central portion of the tube is operatively engaged by the peristaltic pump head so that consecutive portions of the flexible tubing are successively collapsed to thereby propel fluid through the tubing so as to exit the second end. The disposable cartridge is preferably mateable with a recess in a base housing. A transmission system is mounted within the recess of the base housing and arranged to operatively engage the peristaltic pump head. A control module is disposed in control communication with the transmission system for selective operation of the fluid delivery system.

Abstract: A roller pump comprises a pump housing having a cylindrical inner surface, a rotor fixed to a drive shaft placed at the central portion of the pump housing, rollers provided around the rotor and a driver for driving the drive shaft through a reduction gear. The rollers press an elastic tube installed between the rollers and the inner surface of the pump housing to transfer a liquid in the elastic tube by rotation of the rotor. The pump housing and the reduction gear are integrated into one body and an output shaft of the reduction gear is fixed to the drive shaft of the rotor. A stepping motor is used as the driver. A part of the inner surface of the pump housing is composed of a semicircle, another part of the inner surface is composed of a partial circle of which center is shifted from the center of the semicircle.

Abstract: A peristaltic pump for pumping a liquid, such as a juice concentrate, includes a rotor assembly attached to a housing, a band attached to the housing and surrounding at least a portion of the rotor assembly A tube is positionable between the band and the rotor assembly. The position of the band can be adjusted relative to the rotor assembly to adjust the pressure applied to the tube by the band and the rotor assembly. The rotor assembly includes rollers therein for pumping concentrate from a reservoir by drawing a vacuum.

Abstract: A linearized peristaltic pump has a substantially circular elastomeric tube (30) clamped within a pump housing (1) and a plurality of tube-engaging rollers (40) adapted to compress the tube (30) to pump fluid from an inlet end (33) to an outlet end (34). The tube (30) is clamped longitudinally by a circlip (35) so as to have a flattened clamped part (31) and a bulbous unclamped part (32) which is engaged by the rollers (40). The rollers (40) are mounted on the outer ends of spring-loaded rotor arms (42) and move on a cam track (50) to alter the compression of the tube (30) progressively in a tube-encountering sector (E-B) and a tube-releasing sector (C-A).

Abstract: A pump formed from an asymmetric tube, which is pinched to form asymmetric forces, that pump fluid.

Abstract: A pump housing supports a plurality of pump segments each having a raised pump cavity enclosed by a resilient diaphragm sealed to the pump cavity. A compression plate supports a plurality of rollers against the pump segments. The compression plate is rotatable with respect to the pump housing to move the rollers across the pump segments deforming the diaphragms and expelling fluid from the pump segments. Fluid passages couple each pump cavity to a source of fluid and a fluid output. As each roller rolls across each diaphragm to expel fluid from the pump segment, the resilience of the diaphragm draws fluid into the pump segment behind the roller to refill the pump segment.

Abstract: A pump module includes a peristaltic pump having a pump rotor, a drive mechanism to rotate the rotor, and a tubing clamp adjacent to and separate from the peristaltic pump. A cover is movable between a closed position on the pump module, enclosing both the pump rotor and the tubing clamp, and an opened position spaced from the pump module, exposing both the pump rotor and the tubing clamp. The cover carries a tubing organizer, which holds tubing. The tubing organizer serves, as the cover moves toward the closed position, to orient the tubing in a desired way with the pump rotor and tubing clamp. The tubing organizer also serves, as the cover moves toward the opened position, to orient the tubing away from the pump module.

Abstract: A peristaltic type pump for pumping ink to a printing section of a corrugated paperboard finishing machine capable of both pumping ink to the printing section and pumping excess ink from the printing section back to an ink supply as well as pumping a cleaning fluid to the printing section and pumping excess cleaning fluid back to a sump. The pump includes at least one pumping element for pumping the ink or cleaning fluid to the printing section and at least one but preferably two pumping elements for pumping the excess ink or excess cleaning fluid back to the ink supply or sump respectively. Each pumping element includes a rotor having at least two but preferably three or more lobes for compressing two portions of a semicircular portion of a flexible tube surrounding the rotor to confine a finite quantity of ink or cleaning fluid in the tube between two of the lobes in sucession during rotation of the rotor to force the ink or cleaning fluid from an inlet to an outlet of the pump.

Abstract: A peristaltic pump for precision metering of small quantities of fluid through a plurality of flow lines has a plurality of flexible liquid transfer tubes disposed between a set of tube rollers and an arcuate backing plate. The tube rollers are mounted on a roller support which is rotated about a central axis and causes the tube rollers to roll successively along the tubes, compressing the tubes against the arcuate surface of the backing plate and causing the fluid contained within the tubes to flow progressively in the direction of roller movement. The tube rollers are individually gear driven and turn at a rate which provides a roller surface speed equal to the rate of movement along the tubes, thereby eliminating any frictional drag along the tubes. The flexible tubes are mounted on the pump housing under uniform controlled tension to assure that each tube dispenses fluid at an equal rate.

Abstract: A fluid transfer system employing a roller pump for squeezing an elastically deformable tube by a roller to allow fluid to be transferred from a transfer source to a transfer destination, said fluid transfer system being characterized by comprising: a short-cut passageway connecting between an inlet passageway and an outlet passageway of said tube fitted onto said roller pump; and a passageway switching means for selectively bringing fluid into fluid communication with said short-cut passageway.

Abstract: A multiple channel peristaltic metering pump includes a base having a pair of spaced apart bearings, a rotor supported on the base and an occlusion member. The rotor includes a rotation shaft in the bearings and a plurality of rollers mounted thereon. A pair of occlusion rings, which are located concentrically with the rotation shaft by the bearings, position the occlusion member with respect to the rollers. Each of the rollers is rotated about a bearing which is located in an opening having sufficient size to allow expansion of lubricant under high operating temperatures. A hose expansion space adjacent the rotor takes up any elongation of the hoses in order to avoid crimping. Hose spacers in the expansion space prevent hose creep along the rotor.

Abstract: A worm pump has an eccentric worm rotor rotatable in a stator to compress tubes which thus carry respective flowable media so that these media are forced through the tubes. The tubes are received in recesses in the stator wall which preferably is composed of a rubber with a shore A hardness of 90 to 95.

Abstract: A disposable set for a blood processing device comprises an array of flexible tubing and a frame that holds the flexible tubing array with at least two linear segments of the flexible tubing array presented for alignment with at least two axially aligned peristaltic pump rotors.

Abstract: A compact pump assembly includes a plurality of axially aligned peristaltic pumps for activating the flow of liquids through the conduits. A housing containing the pumps, is provided with a removable cover for retaining the pumps in the housing when the cover is closed and for permitting removal of the pumps when the cover is opened. A reversible motor is mounted outside of the housing for driving each of the pumps. The pumps may be independently inactivated by an individual release mechanisms provided on the common closure cover.

Abstract: A pumping apparatus 10 for dispensing multiple component fluid material. The apparatus 10 includes at least first and second flexible tubes. The tubes each have an inlet and an outlet, and each of the inlets is supplied with a different component of the fluid material. A roller or rollers are provided for pressurized engagement with the tubes. The stop plate is engaged with the tubes at a location opposing the pressurized engagement of the roller. A driver mechanism independently moves the roller in pressurized engagement with the tubes, opposed by the stop plate, in a linear direction. Such linear movement carries the desired and variable amounts of fluid material to the tube outlets. An engagement frame supports the tubes, roller, stop plate and driver mechanism. A mixing reservoir is provided having multiple inlets, each of which is engaged with a flexible tube outlet, and a single outlet, such that the fluid material components are combined within the mixing reservoir and provided to the single outlet.

Abstract: To draw samples from a source of liquid, a pumping system measures the amount of liquid being pumped by detecting pump cycles and calculating the pumped liquid from this measurement and stored data including conduit size, pressure head and statistical data to correlate detected pump cycles with volume of liquid pumped. Pressure pulses caused by a peristaltic pump are sensed by a piezoelectric film positioned on an inlet conduit connecting the pump to the source of water and, when the liquid reaches a predetermined point determined by the nature of the pulses, the pulses are counted to determine the number of pump cycles.

Abstract: A drawer loading cassette system for a surgical instrument includes a control cabinet and an assembly head disposed therein which includes a plurality of rollers mounted in circular pattern with each roller having a rotation axis generally parallel to an assembly heads central axis. The assembly head is mounted in the cabinet for rotation about the assembly head central axis and a drawer, configured for engagement with a tubing management cassette, is movably attached to the cabinet in order to provide an open position for loading the the cassette and a closed position for engaging a section of tubing supported by the cassette with the rollers.

Abstract: A peristaltic pump is provided having an adjustable flow regulation provided by an adjustable axial elongation means for the variable elongation of resilient tubing disposed between the associated rotors of a rotary peristaltic pump or the plurality of reciprocal pushers or fingers in a linear peristaltic pump to provide a radial compression of successive sections of the resilient tubing. The rotary or linear peristaltic pump includes a calibrated display and a variable speed electric motor having forward and reversing capabilities along with computer interface control for precisely metering and monitoring the volume of liquids for medical, biological and laboratory applications.

Abstract: A miniature mechanical vacuum pump capable of producing intermediate vacuums on the order of about 10.sup.-1 to 10.sup.-2 Torr is provided by a peristaltic pump. In order to dissipate heat in the pump tubing, a cooling fan provides direct a continuously flow of air onto the pump tubing and pump parts contacting the tubing. The pump produces pressures in the range of about 10.sup.-1 to 10.sup.-2 Torr while consuming only about 17 Watts.

Abstract: A peristaltic pump comprising a rotor and a plurality of removable cartridges associated with the rotor, wherein the occlusion beds of the cartridges are configured to enable the outflow characteristics of the pump to be varied by manipulation or interchanging of the cartridges, such that the pump may, in one mode of operation, have synchronous flow to all of its parallel flow channels, or may in a second mode of operation, have non-synchronous phase-offset flow to respective ones of the parallel flow channels. In the second mode of operation, manifolding of the output flow from respective ones of the parallel flow channels can be employed to provide flow of substantially reduced pulsation. Each of the cartridges preferably comprises a cartridge frame and a separate occlusion bed supported on the cartridge frame. In the second mode of operation, the occlusion beds of the cartridges preferably have regions of maximum occlusion offset relative to one another.

Abstract: A medical peristaltic pump having improved pumping and sealing qualities, as well as providing increased flexibility of use and a high level of security. The pump is assembled from at least three modules, a pump rotor (22) being housed in a first module (36; 172) for compressing at least one tube (28; 28a; 28b) connecting a reservoir (30) for storing a liquid substance to the output (32) of the pump. The compression is effected against at least one support piece (34) of a second module (38, 174). The first and second modules are provided with first positioning elements and first assembly elements in a manner to define a set of two modules for compressing the tube to pump the liquid substance. The set of two modules and a third module (40, 176) are provided with second positioning elements and second assembly elements in a manner such that, once assembled, the third module (40, 176) assures sealing of the first module.

Abstract: A method of assembling a peristaltic pump having a motor housing having a driveshaft extending therefrom and a pump housing containing a pump including a rotor mounted on a stub shaft extending through the pump housing wherein the motor housing and the pump housing are detachably connected together. They are assembled by positioning the motor housing and the pump housing so as to axially align the stub shaft and the driveshaft, and moving the pump housing towards the motor housing in the axial direction of the driveshaft so that the driveshaft enters the pump housing and engages the rotor while the stub shaft is urged axially out of the pump housing. When the pump housing contains two or more rotors the stub shaft preserves the alignment of the rotors both during manufacture of the pump assembly and transportation of the pump housing.

Abstract: A peristaltic pump is provided having an adjustable flow regulation provided by an adjustable axial elongation apparatus for the variable elongation of resilient tubing disposed between the associated rotors of a rotary peristaltic pump or the plurality of reciprocal pushers or fingers in a linear peristaltic pump to provide a radial compression of successive sections of the resilient tubing. The rotary or linear peristaltic pump include a calibrated display and a variable speed electric motor having forward and reversing capabilities along with computer interface control for precisely metering and monitoring the volume of liquids for medical, biological and laboratory applications.

Abstract: The present invention pertains to a device for irrigation of and aspiration from body cavities, especially during surgical laparoscopy, comprising a delivery pump and a suction pump and tubing lines, which are connected to these and lead to the body cavity. A device for irrigation of and aspiration from body cavities, which can be operated in a very simple manner and fully meets sterility requirements is provided.

Abstract: A peristaltic pump is described for operating simultaneously on two fluid lines having different wall thicknesses comprising a rotatable head having rollers and enclosed within a hollow body. The hollow body has a central axis with an internal first cylindrical surface portion at a first radius R from the axis, and a second cylindrical surface portion at a second radius r from the axis. The interspace between the periphery of the respective roller and the respective cylindrical surface portion is arranged to perfectly occlude the respective different sized fluid line.

Abstract: A peristaltic pumping and metering apparatus and method whereby tube walls are squeezed inwardly against cores contained in the tubes. A plurality of rings are frictionally driven in epicyclic manner, to thus deform a contoured belt against the core-containing tubes.

Abstract: A pump (20) has a housing (22) consisting of top (24), bottom (26), sides (28) and (30) and ends (32), (34), and (36) defining a plenum (38). An axially extending passage (40) is formed by the ends (32) and (34), through which flexible tubing (42) passes. The plenum (38) is connected to the passage (40). A pressure block (44) is slideably positioned in the plenum (38) for movement toward and away from the flexible tubing (42). The pressure block (44) has a rectangular opening (46), which receives a circular bearing (48) and a circular cam (50) which is eccentrically mounted on shaft (52). Conventional ball valves (54) and (56) are provided in the flexible tubing (42) above and below the pressure block (44). The lifetime of the tubing is substantially enhanced if the pressure block (24) depresses the tubing (42 ) no more than half of its inside diameter. When this limitation is followed, no creasing or similar localized severe distortion of the tubing (42) takes place.

Abstract: An infustion pump fluid source cartridge having a pump interface portion and a fluid source portion. The top edge of the cartridge is bevelled in the fluid source portion to permit bending of the fluid source portion to securely position the pump interface portion against the pump without distorting the pump interface portion. A pump tube mount is provided for insertion into such cartridge. The pump tube mount includes a uniquely shaped front wall and a rear wall which extends downward in order to butt up against a ledge. Tabs extend from the rear wall in order to snap into an opening beneath the ledge. A compressible tube is mounted in the tube mount by providing a cylindrical fitting having an indentation. The tube may be held in the indentation by a collar surrounding the tube in alignment with the indentation.

Abstract: A variable occlusion device includes a device housing having an occlusion track adapted to receive one or more loops of flexible tubing and having an arcuate reactive surface. The device also includes a rotor member mounted for rotation within the housing about a device axis. The rotor includes a number of carriage passageways or tracks, each passageway or track with an occluding member carriage and occluding member assembly movably mounted therein. The carriage and occluding member assemblies are each adapted to move between an extended position in which the occluding member bears against and collapses the tubing received in the occlusion track, and a retracted position in which the occlusion member is drawn away from and out of contact with the tubing in the occlusion track. The peristaltic device also includes a fluid distribution system for providing an operating fluid from a remote fluid supply under a desired pressure to the carriage passageways of the rotor.