HK1110537B - Automatic clamp apparatus for iv infusion sets used in pump devices - Google Patents

Description

Automatic clamp for intravenous infusion set in pump device

Technical Field

The present invention relates generally to clips used on flexible IV catheters in the field of Intravenous (IV) infusion sets, such as peristaltic pumps, and more particularly to a clamping device that prevents free flow of fluid through the IV catheter when the infusion pump is disengaged from the IV catheter.

Background

Liquids such as medications are commonly delivered intravenously to a patient by a pump device, such as a peristaltic pump. These pumps are useful because they can deliver the medication in a highly controlled and precise manner, and because they do so without requiring contact with the medication. Fluid is delivered through a flexible IV tube by pressing a pumping member against the tube sufficiently to drive fluid in the tube downstream toward the patient. For peristaltic mechanisms having a plurality of pumping fingers, the pumping fingers may be moved against the tube in an upstream to downstream sequential manner to sequentially occlude the tube, thereby driving the liquid in the tube downstream toward the patient. When the IV tube is properly mounted in the pump, the IV tube is always blocked by one of these pumping members, thereby preventing "free flow" of fluid to the patient. The "free flow" of medical fluids is undesirable because such flow of fluids is uncontrolled and does not follow a prescribed treatment regimen.

The peristaltic pumping mechanism is typically housed in a housing with a hinged door. A tube having liquid flowing therein is placed in contact with the pumping mechanism within the door, with the tube ends extending generally from the top and bottom of the door in an open position. When the door is closed over the tube, a pressing member on the inside of the door presses against the IV tube, providing a backing surface that allows the pumping member to occlude the tube. The platen is typically (although not always) a spring loaded against a pumping mechanism so that one or more pumping fingers of the pumping mechanism occlude the tube once the door is closed over the tube. This prevents free flow of liquid when the door is closed.

The arrangement of the IV tube in relation to the pumping mechanism requires some means to prevent liquid flow in the tube when the pump door is open. But as soon as the pump door is opened the duct is released from the occluding pumping mechanism/platen combination and free flow is possible. This can result in uncontrolled infusion of the drug into the patient, or blood from the patient may flow back into the IV line, under the influence of static head pressure in the line. Known devices for preventing unwanted flow in a catheter include manual clamps on the catheter separate from the infusion pump, and automatic occlusion devices mounted on the pump. These manual devices require some manipulation skill from the attending physician and there is always the possibility that the physician will forget to properly time the manual conduit clamping procedure before the pump door opens. Furthermore, the door may be accidentally opened, allowing free flow in the conduit.

Improvements have been made to automated devices mounted on infusion pumps to assist in clamping and unclamping infusion catheters. In particular, improvements have been made to the reliability of the timing of the occlusion and release (non-occlusion) of the tube in the event of disengagement and engagement of the tube with the pumping member, respectively. Typically, the act of opening the door is dependent on the clip beginning to occlude the IV tube, while the act of closing the door is dependent on an IV tube clip beginning to release the tube or beginning to unblock the tube. However, there is still the possibility of inadvertently causing free flow of fluid in the IV tube due to operator error in using such devices.

Accordingly, those skilled in the art have recognized a need for an improved apparatus for automatically and completely occluding an IV tube prior to disengagement of an occluding pumping mechanism from the tube.

Disclosure of Invention

Briefly, and in general terms, the present invention provides a clamp or gripping device for selectively preventing fluid flow through a flexible conduit, comprising: a base having a conduit opening into which said flexible conduit is disposed, said base having a longitudinal centerline; a slide clamp slidably mounted on said base for movement between an occluding position and an open position, said slide clamp having a longitudinal centerline; a clip opening formed in the slide clip for receiving the catheter therethrough; a constriction region formed in the clip opening, the constriction region obstructing the conduit to prevent fluid flow through the conduit when the sliding clip is in the occluding position; an open area formed in the clip opening that allows liquid to flow through the conduit when the slide clip is in the open position; a locking member formed on the slide clamp; and a flexible cantilevered locking arm mounted on said base, said locking arm having a release tab formed on said locking arm but located at a position offset from the longitudinal centerline of said base, said locking arm being biased toward a locked position in which said locking arm engages said locking member of said slide clamp to prevent movement of said slide clamp from said occluding position to said open position, and said release tab being movable to deflect said locking arm, wherein said locking arm is disengaged or disengaged from said locking member to allow subsequent movement of said slide clamp from said occluding position to said open position.

In accordance with another aspect of the invention, the conduit opening of the base slidably receives the resilient conduit such that the base is movable to a selected position along the conduit when the slide clamp is in the open position.

In other aspects of the invention, the locking arm further includes a release tab for releasing the flexible arm from the slide clamp to allow the slide clamp to be subsequently moved from the occluding position to the open position. Further, the base includes a stop surface located adjacent to the release tab at a position to prevent movement of the release tab beyond a preselected range of movement. The slide clamp includes a detent or detent (detente) into which the locking arm is biased and positioned when the slide clamp is in the occluding position to prevent the slide clamp from disengaging the occluding position, the detent being sufficiently sized to receive the locking arm such that there is no stress when the locking arm is in the detent. The slide clamp further includes a ramp to receive the locking arm when the slide clamp is in the open position, the ramp being formed deeper than the arm, whereby the arm is unstressed when the slide clamp is in the flow position. The ramp is formed to guide the locking arm into a detent formed in the slide clamp as the slide clamp moves from the open position to the occluding position, thereby locking the slide clamp in the occluding position.

In still other aspects, the opening of the slide clamp is generally tear-drop shaped, the constricted region includes an elongated slot portion, and the flow region includes a rounded portion, the conduit being located in the slot portion when the slide clamp is in the occluding position and the conduit being located in the rounded portion when the slide clamp is in the open position.

In additional detailed features, the catheter opening includes a catheter hub within which a catheter tip is permanently mounted, the catheter opening includes a fluid passageway through the base, whereby the flexible catheter is connected in fluid communication with the passageway, further, the clamp includes a pressure interface between the flexible catheter and the base, the pressure interface having a pressure diaphragm within a housing, the pressure diaphragm transmitting pressure increases and decreases of the flexible catheter to a pressure sensor within the medical instrument.

According to a further aspect of the invention, the slide clamp further includes a forward pushing flange sized to receive a finger of an operator used to push the clamp into position within the medical infusion pump, the pushing surface being curved. The release tab of the locking arm is located in a position that is not above the pushing flange. In a more detailed aspect, the release tab is located in a lateral position relative to the pushing flange. In addition, the base includes a rounded mounting end, thereby facilitating pressing the clip into an operative position in the infusion pump.

The novel features of this invention, as well as the invention itself (both as to its structure and operation), will be best understood from the accompanying drawings, taken in conjunction with the accompanying description.

Drawings

FIG. 1 is a perspective view of an automatic clamp according to aspects of the present invention, the slide clamp shown in a blocking position in which the slide clamp is partially withdrawn from the base;

FIG. 2 is a front left perspective view of the slide clamp of FIG. 1 showing the opening, detent, ramp and push flange;

FIG. 3 is a lower right perspective view of the slide clamp of FIG. 1 showing the opening, pushing flange and pulling lug;

FIG. 4 is a top plan view of the slide clamp shown in FIGS. 1-3;

FIG. 5 is a left side partial cross-sectional view of the slide clamp shown in FIGS. 1 through 4, showing the pull tab, detent and ramp;

FIG. 6 is a top left perspective view of the base showing the locking arm, release tab and catheter opening;

FIG. 7 is a lower right perspective view of the base showing the locking arm and release tab;

FIG. 8 is a right side plan view of the base showing the release tab;

FIG. 9 is a cross-sectional left side view of the base showing the locking arm and release tab;

FIG. 10 is a left side view of the base showing the catheter opening, release tab, and a portion of the locking arm, illustrating the angle of the locking arm with the top surface of the base;

FIG. 11 is a bottom view of the base;

FIG. 12 is an upper left perspective view of the automated clamp of FIG. 1 with the slide clamp fully inserted into the base to form a flow configuration;

FIG. 13 is an operational view wherein the catheter is occluded by the opening of the slide clamp and the unlocking bump (boss) and pushing bump will move the slide clamp to the open or flow position;

FIG. 14 is an operational view wherein the catheter is unobstructed for flow and the pulling hook will pull the sliding clip to the occluding position; and is

FIG. 15 shows a clamp with a pressure interface device positioned as part of the conduit upstream from the clamp to communicate line pressure to the pressure sensor.

Detailed Description

Referring now more particularly to the drawings in which like reference numerals designate identical or corresponding elements throughout the several views, there is shown in FIG. 1 an automatic clamp apparatus 20 for an intravenous (hereinafter "IV") infusion set for use in a pump set, the clamp apparatus 20 generally comprising a relatively open box-like base or frame 22 and a mating slide clamp 24, both of which can be made of a variety of plastic materials by injection molding The open bottom end 32 is connected to the base and is also formed to be capable of receiving an IV tube or other tube female connector therein if desired, the IV tube and the pumping tube may be the same tube, so that only the IV tube needs to be passed through the tower, the base and the slide clamp so that the automated clamp apparatus 20 can be slid along the tube to a desired position.

Referring now to fig. 2, the slide clamp 24 has an elongated opening 38 extending through its top surface 34 to its lower surface 36. The elongated dimension of the opening 38 in the slide clamp is disposed parallel to the direction of relative sliding movement between the base 22 and the slide clamp 24. The opening 38 in the slide clamp includes an open portion 40 and a blocking portion 42. The open portion is sized to prevent the conduits received in the open portion from being occluded, while the occluded portion is sized to occlude the conduits therein. The width of the slots of the occluding portion is sufficiently small to allow a selected IV tube passing through the slot to be completely occluded and remain occluded under a predictable range of fluid pressures within the IV tube. The range of pressures at which the catheter remains occluded will include at least the static discharge pressure expected during normal use of the infusion device.

The slide clamp 24 further includes a push flange 44 at its front edge 46. The pushing flange is somewhat concave, although the "concave" surface may not necessarily be curved; it may in fact have converging straight surfaces or surfaces of other shapes. The purpose of the push flange is to guide the operator's fingers to the approximate center of the slide clamp to mount the entire automatic clamp apparatus 20 (fig. 1) to an infusion pump. Such an operation may be found in U.S. Pat. No. 6,629,955 to Morris, particularly FIG. 10. U.S. Pat. No. 6,629,955 to Morris is incorporated herein by reference. The operator's fingers are guided to the center of the pushing flange to more easily apply a force along the centerline to the automated clamp, thereby ensuring that the clamp is properly installed on the pump. For convenience, the shape of the pushing surfaces of the pushing flange 44 will be referred to as "concave", although as noted above, these surfaces may not be curved. It should be noted that in this embodiment, the opening 38 is also located on the longitudinal centerline 47 of the slide clamp.

Fig. 2 also shows a detent 48 having a detent edge 50. The specific operation of the detent, which will be described later, is intended to prevent the slide clamp from moving from the occluding position to the open position in the absence of deliberate action. Further shown is a ramp 52 at the front of the slide clamp for receiving the locking arm of the base when the slide clamp is in the open position.

Referring now to the perspective view of fig. 3 and the views of fig. 4 and 5, the bottom surface 36 of the slide clamp 24 includes a pull tab 30 projecting downwardly from the bottom surface that provides a substantially vertical pull surface 56 for engaging a latch (not shown) on the door of the pump housing to partially withdraw the slide clamp 24 from engagement or engagement with the base 22 prior to opening of the door. Pulling or withdrawing the slide clamp from the base portion moves the slide clamp from its open position to the occluding position (fig. 1). The pushing flange 44 of the slide clamp also provides a substantially vertical pushing surface against which the pump door or some other device will push when the door is closing or after it has been closed, so that the slide clamp is fully inserted into the base. Advancing the slide clamp fully inserted into the base moves the slide clamp from its occluding position to its open position. Also shown in fig. 4 and 5 are detent 48 and ramp 52. Both of which are made of the material of the slide clamp, the depth of both being best seen in fig. 5.

Turning now to the base, the base 22 is shown in FIG. 6 with a flexible cantilevered locking arm 60 molded into the top surface 28 of the base with its distal free end 62 biased downwardly below the top surface 28 of the base. the downward biasing of the free end is accomplished by molding the locking arm in a downwardly sloped configuration, although such biasing may also be accomplished by the use of springs or other means. the locking arm 60 is formed with a release tab 64 projecting upwardly from the locking arm in a generally same direction as the tower 26. Note that the release tab 64 is located at a position lateral to the tower 26. the release tab is also offset from the longitudinal centerline 66 of the base. by pressing the release tab 64 in a direction parallel to the centerline 66, the free end 62 of the locking arm 60 can be bent upwardly. without departing from the spirit of the invention, a plurality of locking arms and release tabs offset from the centerline of the base may be used in place of those shown.

It should also be noted that the depth of the detent 48 and the size and angle of the locking arm 60 are carefully selected so that the locking arm is unstressed when it is in the detent. That is, it does not contact the bottom of the stopper, with no significant force applied. This is important because if the locking arm is made of a plastic material or other material that exhibits "creep", it may deform if it is subjected to constant stress over time. For example, if the clamp is stored for an extended period of time in the blocking position (fig. 1) where the locking arm is in contact with the bottom of a shallow detent and is under constant stress due to constant contact with the detent, the locking arm may creep such that the storage position becomes the new rest position of the latch arm. The locking arm will become disabled. Thus, making the detent and locking arm described above such that the arm is not stressed will leave the clamp unaffected by storage. Similarly, the depth of the ramp is also such that the locking arm is unstressed when at the lowest point of the ramp, as shown in the open position in FIG. 12.

The base also includes side edges 68 formed as rails 70 that are parallel to the relative sliding direction of the slide clamp in the base (fig. 1). When the slide clamp 24 is slidably engaged or engaged with the base 22, the slide clamp slidably engages two rail channels 72 in the base. Alignment of the slide clamp with the base is achieved by fitting the slide clamp into the rail channel. Turning now to fig. 7, the guide rails 70 and slots 72 are more clearly illustrated. It should also be noted that the entire proximal end 74 of the base is attached. As previously shown, the central portion 76 is left open to receive the pulling lug of the slide clamp. Likewise, the distal free end 62 of the locking arm and the release tab 64 are more clearly visible.

Fig. 8 illustrates a stop 78 formed on the top surface 28 of the base 22 for limiting the range of motion of the release tab 64. Specifically, the stop surface 80 is spaced from the back of the release tab by a preselected distance so that the release tab is not overstressed by bending too much. Referring also to fig. 9, which shows a cross section of the locking arm 60, the locking arm 60 carries a release tab 64 at its distal end. It should be noted that the locking arm is molded as part of the base and is in the form of a cantilever. The release tab 64 is disposed at approximately 90 degrees to the locking arm, but because the locking arm is made at an angle to the top surface 28 and lower surface 82 of the base 22 to engage the slide clamp, the release tab is at a 90 degree angle to the locking arm rather than a 90 degree angle to the top surface of the base. Fig. 9 more clearly illustrates the locking arm 60 being downwardly inclined to provide the necessary downward bias to engage the detent 48 and locking edge 50 of the slide clamp to prevent the slide clamp from moving to the open position unless the operator purposely acts to disengage the locking arm 60 from the detent.

Referring now to fig. 10, a right side view of the base is provided. As shown, the top surface of the locking arm is angled approximately 172.86 degrees from the top surface 28 of the base. This can also be seen in fig. 9. It has been found that thickening the locking arms and forming the angles shown results in repeatable performance. That is, when the release protuberance 90 (shown in FIG. 13) presses against the release tab 64, the release tab and the locking arm will lift from the base to disengage the assembled slide clamp, releasing the slide clamp for movement to the open position. This problem will be discussed in more detail below. Fig. 11 is a bottom view of the base 22 more clearly showing the distal end 62 of the locking arm which is received by the detent 48 of the slide clamp 24. In addition, fig. 11 shows an opening 49 for the conduit through the base.

FIG. 12 shows the slide clamp 24 and base 22 assembled into an operable automatic clamp apparatus 20 according to aspects of the present invention, and with the clamp apparatus 20 in an open position to allow fluid flow through the clamp apparatus, it can be seen that the distal free ends 62 of the locking arms 60 are located in the ramp 52, and the ramp is made sufficiently deep that the distal free ends 62 of the locking arms do not contact the material of the base, and therefore the locking arms are in an unstressed condition.

Fig. 13 and 14 generally illustrate how the automatic clamp 20 interacts with the door of the pump housing according to aspects of the present invention. Fig. 13 shows the slide clamp 24 in its occluding position relative to the base 22, with the slide clamp partially withdrawn from the base and the distal free end 62 of the locking arm 60 engaged with the detent 48 (not shown) to hold the slide clamp in its occluding position. FIG. 14 shows the slide clamp in the open position with the slide clamp fully inserted into the base and the distal free end 62 of the locking arm bent upwardly sufficiently to clear the detent 48.

The operative components of the door and latch mechanism are schematically illustrated and designated as components 90, 92 and 94 to clarify their interaction with the automatic clamp of the present invention. A release bump 90 may be formed on the door and positioned to contact the release tab 64 and press the tab upward and rearward as the door moves to the blocking position. A push boss 92 may be formed on the latch mechanism and positioned such that when the latch is engaged, the push boss 92 contacts the push flange 44 on the slide clamp 24 to push the slide clamp from its blocking position (fig. 13) to the open position (fig. 14). Finally, one or more pulling hooks 94 may be formed on the latch mechanism and positioned such that when the latch is disengaged, the pulling hooks 94 contact the pulling tab 54 to pull the slide clamp 24 from its open position to the blocking position.

As shown in fig. 13, when the pump door is moved to the closed position, the door release protuberance 90 and the pushing protuberance 92 move generally to the right. The pulling hook 94 of the latch mechanism can be made to move generally to the left when the latch is disengaged and generally to the right when the latch is engaged, as seen in fig. 14, it being understood that the other components of the latch mechanism (not shown) perform the actual latching of the door in the closed position. In addition, the pulling hook 94 can be rotated in a clockwise direction from the position shown against the biasing spring relative to the rest of the latch mechanism. For convenience, the tubing passing through the automated clamp 20 is represented in fig. 13 and 14 as conduit 96. In fig. 13, the catheter 96 is occluded by the slide clamp opening and extends into the occluding slot of the opening. In fig. 14, the conduit is in flow mode. As described above, the conduit may be used as a pipe passing through the jig 20, or may not be used as a pipe passing through the jig 20. A tower may be used with the conduit sections made to the tower.

Referring briefly to fig. 15, the inclusion of a pressure interface device 100 upstream of the automated clamp apparatus 20 is shown. The pressure interface device may take the form of a pressure diaphragm sized and configured to be mounted to a pressure sensor that is part of an infusion pump to which the clamp is mounted. Such a pressure diaphragm is described in U.S. patent No. 4,398,542 to Cunningham, which is incorporated herein by reference. U.S. Pat. No. 4,404,440 to Busche, also incorporated herein by reference, describes a sensor that may be used with such a pressure diaphragm. Installing such a pressure diaphragm in a pipeline with the automatic clamp of the present invention would limit the movement of the clamp along the pipeline because of the need to place the clamp close to the pressure diaphragm installed in the pump. In this case, the tower 26 may be used as a mounting seat for the pressure diaphragm device.

Operation of

To use the automatic clamp apparatus 20 of the present invention, it is ensured that the slide clamp 24 is in the occluding position, as shown in FIG. 1, because the locking arm 60 is in the detent 48, the slide clamp cannot be moved from the occluding position to the open position unless the release tab 64 is actuated, when the locking arm is in the detent 48, there is no stress. The release tab is moved by an operator pressing one finger to disengage the locking arm upwardly from the detent and the push flange is pressed with the other finger to move the slide clamp to the open position when the slide clamp is inserted into the base, the locking arm moves down the ramp 52 to the bottom of the ramp (FIG. 12) where the locking arm is unstressed.

The door of the pump housing is opened and the automatic clamp 20 is properly installed into the pump both above and below its conduits. The pushing flange is used by the operator to receive the operator's finger to push the clamp into the appropriate cavity of the pump. The clamp should remain in the occluding configuration when installed in the pump. Because the release tab is off-center with respect to the pushing flange, the likelihood of the operator pressing the release tab as or with the pushing flange is greatly reduced.

The upstream and downstream conduits are now joined or connected together in the presence of other devices, such as an air-in-line sensor, pressure sensor, etc. In particular, the pumping duct 96 is placed in contact or connection with the pumping mechanism and the door is then closed. Fig. 13 shows the slide clamp 24 in its occluding position, with the release boss 90 in contact with the release tab 64 when the pump door is closed. When the door is fully closed, the release boss 90 pushes the release tab 64 upward, thereby bending the locking arm 60 upward out of the detent 48, allowing the slide clamp to move so that it can be inserted into the base. When the door is fully closed, the latching mechanism is latched, causing the push boss 92 to push the slide clamp 24 to insert into the base to its open position, as shown in fig. 12. FIG. 14 shows the slide clamp 24 in the open position with the pulling hook 94 rotated behind the pulling lug 54. The pump can then be operated in a conventional manner to purge the IV line 96 of air, and the IV line 96 can then be connected to the venous access site.

When the pump door is to be opened, the protuberance 92 and pull hook 94 will move to the left, causing the pull hook 94 to contact the pull tab 54 of the slide clamp 24 and withdraw the slide clamp 24 from the base into the occluding position. The latching mechanism can be constructed in a known manner so that the door cannot be unlatched until such jamming occurs. At this time, the door can be opened. Because the locking arm 60 is already engaged with the detent 48, the locking arm can still hold the slide clamp 24 in the occluding position even though the slide clamp 24 is pushed toward the base 22 with a substantial force.

The latching mechanism can also be configured in a known manner such that, when the door is unlatched, it cannot be moved back to the latched position until the door is closed. Thus, if the door is to be closed, the release protuberance 90 will push the release tab 64 upward, disengaging the locking arm 60 and detent 48 from engagement, and the slide clamp 24 can then be moved to the open position, as explained previously.

While the particular automated clamp apparatus as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.

Claims (20)

1. A clamp for selectively preventing fluid flow through a flexible conduit, comprising:

a base having a conduit opening into which said flexible conduit is disposed, said base having a longitudinal centerline;

a slide clamp slidably mounted on said base for movement between an occluding position and an open position, said slide clamp having a clamp top surface and a longitudinal centerline;

a clip opening formed in the slide clip for receiving the catheter therethrough;

a constriction region formed in the clip opening, the constriction region obstructing the conduit to prevent fluid flow through the conduit when the sliding clip is in the occluding position;

an open area formed in the clip opening that allows liquid to flow through the conduit when the slide clip is in the open position;

a flexible cantilevered locking arm mounted on the base, the locking arm biased at a selected angle to a top surface and a lower surface of the base toward the slide clamp to a locked position where the locking arm prevents movement of the slide clamp from the occluding position to the open position, the locking arm being deflectable to allow subsequent movement of the slide clamp from the occluding position to the open position; and

a detent in said slide clamp defined by a detent edge and a ramp-shaped bottom at a depth below said clamp top surface, said detent being adapted to a selected angle of said locking arm such that when said slide clamp is in said blocking position, a distal free end of said locking arm is positioned in said detent to engage said detent edge without contacting said ramp-shaped bottom of said detent, thereby preventing said slide clamp from moving out of said blocking position and thereby maintaining said locking arm unstressed.

2. The clamp of claim 1, wherein a conduit opening in the base slidably receives the resilient conduit such that the base is slidable along the conduit to a selected position when the slide clamp is in the open position.

3. The clamp of claim 1, wherein the locking arm further comprises a release tab for releasing the locking arm from the slide clamp to allow the slide clamp to be subsequently moved from the occluding position to the open position.

4. The clamp of claim 3, wherein the base further includes a stop surface located adjacent to the release tab at a position to prevent movement of the release tab beyond a preselected range of movement.

5. The clip of claim 3, wherein the release tab is located at a position offset from a longitudinal centerline of the base.

6. A clamp according to claim 5, wherein the release tab is arranged to deflect the locking arm away from the detent, thereby allowing the slide clamp to be subsequently moved from the occluding position to the open position.

7. The clamp of claim 1, wherein said slide clamp further comprises a ramp to receive said locking arm when said slide clamp is in said open position, said ramp being made deeper than said arm, whereby said arm is unstressed when said slide clamp is in said open position.

8. The clamp of claim 7, wherein the ramp is formed to guide the locking arm into the detent formed in the slide clamp as the slide clamp moves from the open position to the occluding position, thereby locking the slide clamp in the occluding position.

9. The clamp of claim 1, wherein:

the clip opening is generally tear drop shaped;

said constricted region comprising an elongate slot portion;

the open area includes a circular portion;

the conduit is located in the slotted portion when the slide clamp is in the occluding position; and is

The conduit is located in the rounded portion when the slide clamp is in the open position.

10. The clamp of claim 1, wherein said conduit opening comprises a tower, the top end of said tower being formed as a female conduit fitting into which said flexible conduit is attached.

11. The clamp of claim 1, wherein said conduit opening includes a fluid passage through said base, whereby said flexible conduit is connected in fluid communication with said passage.

12. The clamp of claim 1, further comprising a pressure interface between the flexible conduit and the base, the pressure interface having a pressure diaphragm in a housing, the pressure diaphragm transmitting pressure increases and decreases of the flexible conduit to a pressure sensor.

13. The clamp of claim 3, wherein said slide clamp further comprises a forward pushing flange of sufficient size to accommodate a finger of an operator used to push said clamp into position within a medical infusion pump, said pushing surface of said pushing flange being curved.

14. The clip of claim 13, wherein the release tab is located in a position that is not behind the pushing flange.

15. A clip as set forth in claim 14 wherein said release tab is located at a lateral position relative to said pushing flange.

16. The clamp of claim 1, wherein:

the locking arm further includes a release tab for releasing the locking arm from the slide clamp to allow the slide clamp to subsequently move from the occluding position to the open position;

said base further including a stop surface located adjacent to said release tab at a position to prevent movement of said release tab beyond a preselected range of movement;

said slide clamp including a ramp surface that receives said locking arm when said slide clamp is in said open position, said ramp surface being formed deeper than said locking arm whereby said locking arm is unstressed when said slide clamp is in said open position, said ramp surface being further formed to guide said locking arm into said detent formed in said slide clamp as said slide clamp moves from said open position to said blocking position thereby locking said slide clamp in said blocking position;

said slide clamp further comprising a forward pushing flange of sufficient size to receive a finger of an operator used to push said clamp into position within a medical infusion pump, said pushing surface of said pushing flange being curved; and also

The release tab is located in a position that is not behind the pushing flange.

17. A clip as set forth in claim 16 wherein said release tab is located at a lateral position relative to said pushing flange.

18. A clamp for selectively preventing fluid flow through a flexible conduit, comprising:

a base having a conduit opening into which said flexible conduit is disposed, said base having a longitudinal centerline;

a slide clamp slidably mounted on said base for movement between an occluding position and an open position, said slide clamp having a longitudinal centerline;

a clip opening formed in the slide clip for receiving the catheter therethrough;

a constriction region formed in the clip opening, the constriction region obstructing the conduit to prevent fluid flow through the conduit when the sliding clip is in the occluding position;

an open area formed in the clip opening that allows liquid to flow through the conduit when the slide clip is in the open position;

a flexible cantilevered locking arm mounted on said base, said locking arm biased toward a locked position to prevent movement of said slide clamp from said occluding position to said open position, said locking arm having a release tab at a location offset from a longitudinal centerline of said base for deflecting said locking arm away from said locked position to allow movement of said slide clamp to said open position;

a detent in the slide clamp, the locking arm biased to and located in the locked position when the slide clamp is in the occluding position to prevent the slide clamp from exiting the occluding position, the detent being sufficiently sized to receive the locking arm such that there is no stress when the locking arm is in the detent;

a stop surface located on the base at a position adjacent the release tab to prevent movement of the release tab beyond a preselected range of movement; and

a ramp on the base to receive the locking arm when the slide clamp is in the open position and guide the locking arm into a detent formed in the slide clamp as the slide clamp moves from the open position to the occluding position, thereby locking the slide clamp in the occluding position, the ramp being made deeper than the arm, whereby the locking arm is unstressed when the slide clamp is in the open position.

19. The clamp of claim 18, wherein said slide clamp further comprises a forward pushing flange of sufficient size to accommodate a finger of an operator used to push said clamp into position within a medical infusion pump, said pushing surface of said pushing flange being curved.

20. The clamp of claim 18, wherein said conduit opening comprises a conduit sleeve within which a conduit end is permanently mounted.