Apparatus and method for preventing free flow in an infusion line

IS 2 550 797 T3

DESCRIPTION

Apparatus and method for preventing free flow in an infusion line

Background of the invention

1. Field of the invention

The present invention relates to an apparatus and a method for preventing free flow during enteral or parenteral administration of solutions through an infusion line. More particularly, the present invention relates to an occluder / valve and to a method of using infusion sets and the like, wherein the occluder / valve prevents undesirable free flow of solution through the infusion set while allowing a controlled flow through the infusion set.

two. State of the art

The use of infusion sets to administer solutions to patients is well known in the medical arts. Infusion sets are used for both enteral and parenteral applications. Enteral feeding pumps are used to provide patients with nutrition and medication when they are unable, for various reasons, to eat normally. Parenteral solutions (intravenously) are provided to patients to ensure adequate hydration and provide the necessary nutrients, minerals, and medications. Often the infusion set is placed in a free vertical arrangement where gravity forces the solution into the patient. The speed at which the solution enters the patient can be more or less controlled by various clamps, such as roller clamps, that are currently available on the market.

Examples of prior art devices include WO 96/19636 A, US 4,373,524 A, US 4,689,043 A, US 4,932,629 A and WO 98/05378 A1.

In many applications, it is necessary to precisely control the amount of solution entering the patient. When this is the case, a regulating device, such as an enteral feeding pump, is placed along the infusion set to control the rate at which the solution is delivered to the patient. In applications where a pump, etc., is used, the clamps used to regulate the flow are normally opened to their full extent to prevent the clamp from interfering with the proper operation of the pump. The clamp is opened with the expectation that the enteral feeding pump controls the flow of fluid through the infusion set.

It is not uncommon for emergency or other distractions to prevent medical personnel from properly loading the infusion set into the enteral feeding pump. When the infusion set has not been properly loaded into the pump and the clamp has been opened, a situation known as free flow often develops. The force of gravity causes the solution to flow freely into the patient not checked by the pump or other regulating device. Under a free flow condition, an amount of solution many times the desired dose can be delivered to the patient within a relatively short period of time. This can be particularly dangerous if the solution contains powerful medications and / or the patient's body is not physically strong enough to cope with the large influx of solution.

Numerous devices have been developed in an attempt to avoid free-flow conditions. However, such devices generally significantly increase the overall cost of the infusion set and some provide only marginal protection against free flow.

Therefore, there is a need for a device that prevents a free-flow condition, while allowing controlled flow through the infusion set. There is also a need for such a device that prevents free flow if an infusion set is not properly mounted on a pump or other regulating means. Furthermore, there is a need for a device that prevents free flow and is inexpensive and easy to use.

Summary of the invention

According to one aspect of the present invention, there is provided an apparatus according to the preamble of claim 1. Preferable features are defined in the dependent claims.

An object of the present invention is to provide an apparatus for occluding infusion sets to avoid an accidental free flow condition.

Another object of the present invention is to provide an occluder that is simple to manufacture and use.

Another object of the present invention is to provide such an occluder which is inexpensive and therefore disposable.

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Yet another object of the present invention is to provide an occluder that occludes fluid flow through the infusion set unless the infusion set is properly loaded into a flow control mechanism such as an enteral feeding pump.

Still a further object of the present invention is to provide such an occluder which allows simple manual actuation of the occlusion function.

Yet another aspect of the present invention is to provide an occluder that functions as a valve to effectively control fluid flow through a flexible conduit. The above and other objects of the invention are realized in an apparatus to prevent free flow in an infusion set. In accordance with one aspect of the invention, an occluder is provided within the infusion set. The occluder is configured to prevent free flow of fluids in the infusion set beyond the occluder. However, the occluder is also configured to allow solutions to pass selectively through the occluder, which are pumped by an enteral feeding pump and the like.

According to one embodiment of the invention, the occluder is formed by a stop placed on the tubes of the infusion set. The stopper limits flow through the tube by limiting flow around and / or through the stopper when the solution is subject to flow due to gravity. However, when higher pressures are applied to the solution, such as those produced by a pump, the solution is able to flow around and / or through the stopper, thereby delivering the solution to the patient.

Examples to aid in understanding the invention include an occlusion valve provided in the infusion set. The valve prevents free flow through the infusion set due to gravity, while allowing controlled flow of solution through the infusion set.

According to another example, the occluder is configured to stop the flow of fluid until the infusion set has been properly loaded into a control mechanism, such as a pump. Once properly positioned, the interaction between the occluder and the infusion set effectively opens the infusion set to allow the solution to flow through.

According to yet another example, the occluder may be formed integrally with the infusion set or it may be formed as a separate piece or pieces which are then placed in the infusion set to selectively occlude the flow of solution therethrough.

In accordance with yet another example, the occluder may function as a valve to selectively allow fluid flow therethrough. A pair of occluders and an infusion line can be used in conjunction with a piston or other force applicator to form a linear peristaltic pump that delivers predetermined amounts of fluid to a patient.

According to yet another example, the occluder and infusion line can be formed to nest in and open by a conventional fluid flow pump.

Brief description of the drawings

The foregoing and additional objects, features, and advantages of the invention will be apparent from a consideration of the following detailed description presented in connection with the accompanying drawings in which:

Figure 1 shows a perspective view of an infusion set made according to the prior art;

Figure 2A shows a fragmentary side cross-sectional view of an apparatus and method for preventing free flow through an infusion set in the form of an occluder mounted on an infusion set with the occluder and infusion set in a closed configuration;

Figure 2B shows a fragmentary, side cross-sectional view similar to that of Figure 2A, in which the occluder and infusion set are in an open configuration;

Figure 2C shows a side, fragmentary cross-sectional view of an alternative infusion set / occluder configuration made in accordance with the principles of the present invention;

Figure 3A shows a side, fragmentary cross-sectional view of an alternative apparatus and method for preventing free flow through an infusion set in accordance with the principles of the present invention;

Figure 3B shows a fragmentary, cross-sectional view of an example of the alternative occluder, with the occluder and infusion set being arranged in a closed configuration;

Figure 3C shows a cross-sectional view of the example of the occluder of Figure 3A with the occluder and infusion set being arranged in an open configuration;

Figure 3D shows a fragmentary, side cross-sectional view of another example of an occluder and infusion set made in accordance with the principles of the present invention;

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Figure 3E shows a fragmentary side cross-sectional view of yet another example of an occluder and infusion set made in accordance with the principles of the present invention;

Figure 4A shows the fragmentary side cross-sectional view of another example of an occluder and infusion set with the occluder in a closed configuration;

Figure 4B shows a cross-sectional view of the example of Figure 4A in an open configuration;

Figure 5A shows a fragmentary cross-sectional view of an occluder and infusion set with the occluder and infusion set being in a closed position;

Figure 5B shows a cross-sectional view taken along plane 5A-5A of Figure 5A;

Figure 5C shows a fragmentary side cross-sectional view of an infusion set with an occluder disposed therein, with the infusion set being mounted on a control mechanism to maintain the infusion set and occluder in an open configuration;

Figure 5D shows a cross-sectional view taken along plane 5B-5B of Figure 5C;

Figure 5E shows a perspective view of a housing of a control mechanism as it can be used to maintain the infusion set and occluder in an open position as shown in Figure 5D;

Figure 6A shows a fragmentary side cross-sectional view of an infusion set having an occluder formed therein;

Figure 6B shows a view similar to that shown in Figure 6A with the occluder held in an open position;

Figure 7 shows another configuration of an occluder;

Figure 8 shows another configuration of an occluder;

Figure 8A shows a cross-sectional view of another configuration of an occluder;

Figure 8B shows a cross-sectional view of yet another configuration of an occluder;

Figure 9 shows yet another aspect of the invention in which the occluder forms part of a liquid control valve;

Figure 10 shows a perspective view of a clamp for retrofitting existing pumps for use with an occluder of the present invention;

Figure 11 shows a side cross-sectional view of a pair of occluders and the infusion line that form a pair of valves, and a force applicator to form a linear peristaltic pump;

Figure 12A shows a front view of a prior art enteral feeding pump with an occluder r;

Figure 12B shows a close-up cross-sectional view of the occluder, infusion set, and a portion of the pump to demonstrate opening a fluid flow path around the occluder;

Figure 13A shows a side view of an alternate example of an occluder;

Figure 13B shows a cross-sectional view of the embodiment of the occluder of Figure 13 taken along line 13A-13A;

Figure 13C shows an end view of the occluder of Figures 13A and 13B; Y

Figure 13D shows a top view of an enteral feeding pump having an infusion set disposed therein, with an occluder located on the infusion set to prevent free flow through the infusion set.

Detailed description

Reference will now be made to the drawings in which the various elements of the present invention are given numerical designations and in which the invention will be described in order to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only one example of the principles of the present invention, and should not be construed as limiting the pending claims. Additionally, while various embodiments will achieve some of the objectives set forth above, it will be understood that some embodiments may not achieve all of the objectives and the objectives should not be viewed as a limitation of the pending claims.

Referring to Figure 1, a perspective view of an infusion set 10 and related structures is shown in accordance with the teachings of the prior art. Disposed at one end 10a of the infusion set 10 is a bag 14 for the containment of parenteral or enteral solutions. Typically, the bag 14 is supported by a stand 18 that supports the bag approximately 1.83m (6 feet) from the ground.

The opposite end 10b of infusion set 10 is connected to a patient (not shown). In parenteral use, the end of the infusion set 10 would have a needle attached thereto that extends into the venous system of the patient. In enteral use, the end 10b would normally have an accessory that attached to a balloon catheter (not shown) mounts to a stoma in the stomach of the patient. The end can also be connected to a nasoenteric feeding tube.

The solution flows under gravity from the upper end 10a of the infusion set 10 to the lower end 10b. The pressure on the fluid is 9.79 kPa per meter (0.433 psi per foot). Therefore, if the bag 14 is positioned 1.52m (five feet) above the patient, the pressure at the lower end 10b of the infusion set 10 is approximately 14.93 kPa (2.165 psi). From the extreme height of 2.44m (8ft) from the ground, the solution in the

ES 2 550 797 T3 infusion set 10 can reach approximately 24.13 kPa (3.5 psi).

To control the flow of solution through infusion set 10, the infusion set is typically mounted through a flow control portion of a pump 22. Pump 22 selectively allows a metered amount of solution to pass distally (water bottom) of the pump. This can be accomplished in a number of ways. For example, many enteral feeding pumps are peristaltic pumps that have a rotor that engages the infusion set 10 with a plurality of rollers. Each partial rotation of the rotor allows a predetermined dose to pass to the patient. By controlling the speed at which the rotor rotates, the pump can deliver very precise doses of the solution.

Other known pumps in the art flow control solution through infusion set 10 by a plurality of fingers that engage the infusion set. By controlling the position and frequency of engagement of the fingers against the infusion set 10, a highly accurate dose can be delivered to the patient.

While the pump 22 controls the flow of the solution through the infusion set 10 when the infusion set has been loaded correctly, failure to load the infusion set correctly into the pump can quickly result in a free-flow condition at the pump. solution is flowing uncontrollably through the infusion set. To prevent free flow, a clamp 26 is arranged along the infusion set 10. Typically, clamp 26 is disposed above pump 22. A common type of clamp 26 is a roller clamp that allows some control over the presence of flow and volume of flow through the infusion set 10. Other clamps provide just an on / off control.

Although infusion set 22 must be mounted on pump 22 before or immediately after opening of the clamp, this is not always done. There are many situations in a hospital or nursing facility where the nurse or physician must be absent or otherwise distracted prior to proper placement of the infusion set 10. If the clamp has already been opened, the The result is that the solution in bag 18 flows uncontrollably to the patient.

In many situations, the free flow of the solution will not cause any real threat to the patient. In some situations, however, free flow can cause serious injury or even death to the patient. For example, a critically ill patient may go into severe shock if a large amount of solution suddenly flows into his body. Similarly, a patient receiving a strong drug solution can be seriously injured if the solution that was designed to be delivered in a number of hours is delivered within a few minutes.

To address such concerns, compression clamps may be provided on the infusion set 10. The compression clamp automatically closes the infusion set unless it is properly mounted on the infusion set 10. An example of such a compression forceps is disclosed in US Patent No. 5,810,323.

While compression clamp occluders are a significant advantage over the possibility of free flow, they are relatively expensive to manufacture. While such an occluder may only cost ten to twenty cents, using a new occluder with each infusion set adds a proportionally significant amount to the cost of an infusion set. Therefore, there is a need to find an apparatus and method for preventing free flow in an infusion set that is reliable and less expensive than that of the prior art.

Turning now to Figure 2A, there is shown a fragmentary cross-sectional view of an infusion set, indicated generally at 100, with a stopper or occluder 104 disposed therein. The infusion set 100 is formed of an elongated tube 108 made of a flexible, elastic material, such as silicone rubber, latex, polyurethane, neoprene, or numerous similar medical grade materials. (In light of the present disclosure, those skilled in the art will appreciate that the present invention can be used in non-medical contexts as well. In such situations, the tube can be made from materials that are not medical grade).

The occluder 104 has an outer diameter that is slightly larger than the inner diameter of the tube that forms the infusion set 100. This causes a portion 108a of the tube to stretch slightly as it passes over the occluder 104.

Occluder 104 prevents flow through infusion set 100 based on gravity. Thus, the size of the occluder 104 will depend on the material used to form the infusion set. In a presently preferred embodiment, infusion set 100 is formed from a tube made of silicone rubber. The tube has a wall thickness of approximately 0.965mm (0.038 inches) and an inside diameter of approximately 3.302mm (0.130 inches). Occluder 104 is preferably formed of a plastic (eg, acrylic (PMMA), polycarbonate, etc.) or a stainless steel ball bearing having an outer diameter of 3.581 mm (0.141 inches).

Because the occluder 104 is larger than the inside diameter of the infusion set 100, the solution

ES 2 550 797 T3 is only under the force of gravity, it will stand behind the occluder and will not pass. To prevent occluder 104 from gradually working its way downstream, a projection 112 may be formed on infusion set 100 or, as explained in detail below, the occluder may be attached to a connector or some other stationary structure.

Because the infusion set 100 is made up of an elongated, elastic tube 108, the increase in pressure will cause the inside diameter of the tube to expand. When the tube 108 is sufficiently expanded, the portion 108a of the tube passing over the occluder 104 allows the solution to flow around the occluder and into the distal portion 100b of the infusion set 100, as shown in Figure 2B.

Preferably, the occluder 104 and infusion set 100 are selected so that up to 27.58 kPa (4 psi) can be maintained upstream of the occluder, that is, in the proximal portion of the infusion set, before the portion 108a of the elongated tube 108 that extends over the occluder expands sufficiently to allow any clinically significant amount of the solution to pass through.

While the solution hanging in bag 18 may develop 2-3 psi (13.79 to 20.68 kPa) due to gravity, it will not have enough pressure to pass through occluder 104 without the application of a force. external. In contrast, an enteral feeding pump or other type of pump will typically generate between 34.47 and 103.42 kPa (5 and 15 psi). When the solution is pressurized to 34.47 and 103.42 kPa (5 to 15 psi) by the pump, the solution is under sufficient pressure to pass around the occluder 104 for delivery to the patient. In other words, if the infusion set 100 is not properly mounted on the pump so that the pump will generate a higher pressure in the proximal portion 100a of the infusion set, the occluder 104 inhibits flow to the patient. Therefore, there can be no free flow while accommodating the flow of the solution to the patient when the infusion set 100 is properly mounted on the pump.

Turning now to Figure 2C, there is shown a fragmentary, side cross-sectional view of an alternative configuration of an infusion set, indicated generally at 130, and of the occluder 104. As with Figure 2B, the occluder 130 is formed by a small sphere, usually formed of a biologically inert plastic or stainless steel. The infusion set 130 is formed of a first tube 134 and a second tube 138. The first tube 134 is formed of an elastic polymer or silicone so that the tube can expand under pressure. The second tube 138 is normally slightly smaller than the first tube 134 so that the distal end 134a of the first tube can be attached to the outside of the proximal end 138a of the second tube.

To ensure that the occluder 104 does not advance distally in the second tube 138, the second tube 138 is preferably formed of a material that is semi-elastic or non-elastic and therefore will not account for the advancement of the occluder 104. To To prevent proximal end 138a of second tube 138 from forming a seal with occluder 104, the proximal end preferably has one or more notches 142 or contours formed therein. The notches 142 or contours ensure that the liquid will be able to flow around the occluder 104 even if the occluder is pressed firmly against the proximal end 138a of the second tube 138.

When pressures of less than about 27.58 kPa (4 psi) are disposed proximally from the occluder 104, the first tube 134 engages the occluder and prevents liquid from flowing downstream. Once the pressure on the proximal side of the occluder 104 exceeds approximately 27.58 kPa (4 psi), the distal end 134a of the first tube 134 is expanded and the liquid is allowed to flow in the manner shown by arrows 146. Once the pressure drops, the first tube 134 returns to its original size and the liquid flow ends until the pressure rises above the threshold again.

During use, infusion set 130 and occluder 104 prevent free flow unless the infusion set is placed in coupling with a pump that can generate enough pressure to drive flow around the occluder. Once past the occluder 104, the pressure of the liquid drops rapidly to a conventional level and there is no danger to the patient.

Turning now to Figure 3A, a fragmentary, cross-sectional view of another exemplary principle is shown to aid in understanding the present invention. An infusion set 160 has a proximal portion 160a and a distal portion 160b. Disposed between proximal portion 160a and distal portion 160b is an occluder or stopper 164. Stopper 164 is disposed on infusion set 160 to selectively prevent flow from proximal portion 160a to distal portion 160b.

Stop 164 includes a proximal end 164a and a distal end 164b. Starting at the proximal end 164 is a channel 170. As shown in Figure 3A, the channel has a proximal portion 170a and two distal portions 170b that are in fluid communication with the proximal portion. Although the proximal portion 170a is disposed in continuous communication with the interior of the proximal portion 160a, each of the distal portions 170b of the stop 164 is normally disposed in communication with the side wall of the infusion set 160. The side wall of the set Infusion pump 160 normally prevents fluid flow out of distal portions 170b of channel 170.

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Preferably, the side wall will have sufficient resistance to expansion so that a pressure of approximately 27.58 kPa (4 psi) can be placed in channel 170 without causing infusion set 160 to radially distend or expand. Therefore, if the pressure in the proximal portion 160a of the infusion set 160 is less than about 27.58 kPa (4 psi), the liquid will not flow through the stopper 164.

As shown in Figure 3A, stop 164 is relatively long. To stay in place, the stopper 164 frictionally engages the side wall that defines the infusion set 160. By providing a stop 164 that is long, a greater surface area is provided to engage the side wall and prevent the stop 164 from seizing. move slowly downstream.

Turning now to Figure 3B, a fragmentary side cross-sectional view of an infusion set is shown, indicated generally at 180. The infusion set 180 includes a proximal (upstream) end 180a and a distal (downstream) end 180b which are separated by an occluder or stop 184. Stop 184 is similar to stop 164 shown in Figure 3A in that it has a channel 190 with a proximal portion 190a and a pair of distal portions 190b.

Rather than relying on an elongated body and frictional engagement with the side wall of infusion set 180, stop 184 has at least one projection 194 extending outward from the stop to engage the side wall of the set. infusion and prevent advance. Preferably, projection 194 is formed by an annular projection, or a plurality of spaced projections extending radially outward from stop 184.

Turning now to Figure 3C, a cross-sectional view of the infusion set 180 and stopper 184 of Figure 3B is shown. As the pressure in the proximal portion 180a of the infusion set 180 increases to greater than about 27.58 kPa (4 psi), the infusion set is radially distended. This allows liquid contained in proximal portion 180a of infusion set 180 to flow into proximal portion 190a of channel 190, distal channel portions 190b, and distal portion 180b of infusion set. Once the pressure drops below approximately 27.58 kPa (4 psi), the infusion set 180 will retract and the flow in channel 190 will die off as the side wall of the infusion set covers the distal portions 190B of channel 190.

Thus, the embodiments shown in Figures 3A through 3C prevent free flow by preventing fluid flow below 27.58 kPa (4 psi). Once the infusion set 180 is properly mounted on the pump, the increase in pressure created by the rotation of the rotor (or other pressure source) overcomes the flow restriction imposed by stopper 184. When combined with the control provided by the various types of infusion pumps, the occluder or stopper 164 or 184 allows a predetermined amount of liquid to flow through the infusion set 160 or 180 while avoiding the hazards of conditions free flow.

Figure 3D shows a side cross-sectional view of an infusion set, indicated generally at 200, having an occluder or stop 204 disposed therein. The infusion set 200 includes a proximal portion formed by a first tube 208 and a distal portion formed by a second tube 212. The proximal end 212a of the second tube 212 mounts on the outside of the distal end 208a of the first tube 208.

Disposed at the distal end 208a of the first tube 208 and at the proximal end 212a of the second tube 212 is the stop 204. The stop 204 has a channel 216 that extends from a proximal end 204 of the stop to a radially lateral position adjacent to the end. distal 204b of the stop. Therefore, the channel is in fluid communication with the liquid in the first tube 208, but is normally isolated from the interior of the second tube 212.

When the pressures in the first tube exceed approximately 27.58 kPa (4 psi), the proximal end 212a of the second tube 212 expands radially, thereby opening the distal end of the channel 216 and allowing liquid to flow into the portion. distal of the infusion set formed by the second tube 212.

By positioning the stop 204 at the ends of two tube segments, the stop can be adhesively attached to either tube to prevent distal movement of the stop. This can be achieved without interfering with the ability of the stopper to prevent flow below approximately 27.58 kPa (4 psi), while allowing pressures above approximately 27.58 kPa (4 psi) to pass through the infusion set.

While the embodiments of Figures 3A through 3D show examples where the proximal end of the channel is in continuous communication with upstream flow and the distal end of the channel is normally closed, the stop 164, 184 or 204 could be rotated so that the proximal or upstream portion of the channel is normally closed by the side wall of the infusion set 160, 180 or 200 and the distal portion of the channel is always in communication with the distal portion of the infusion set.

Figure 3E shows yet another example of an infusion set, indicated generally at 230, and an occluder 234. The occluder 234 is arranged in the infusion set 230 in order to divide the infusion set 230 into a proximal portion, waters. upstream 230a and a distal portion, downstream 230b.

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The occluder 234 has a channel 238 that extends from a proximal end 234a of the occluder to the distal end 238b in order to form a passageway through which an infusion liquid, such as enteral feeding solution, can be passed. A wall 242 is disposed along the channel 238 to selectively prevent flow through the channel. In accordance with the principles of the present invention, wall 242 is pivotally attached to occluder 234 such that the wall will not move to allow fluid flow through the channel until proximal, upstream pressure exceeds 27 , 58 kPa (4 psi). (While it has been described as requiring an upstream pressure threshold, in light of the present disclosure those skilled in the art will appreciate that the wall will move based on a pressure differential between the proximal and distal ends of the infusion. Therefore, the same effect could be generated by developing a vacuum downstream of the occluder 234). Those skilled in the art will appreciate that the above embodiments could be designed for other thresholds as well.

Once the desired pressure threshold has been reached, wall 242 will pivot and open channel 238 for flow. Once the pressure drops, the wall 242 will pivot to close according to a method of use. However, according to another method of use, the wall 242 may have a notch 246 formed therein. Wall 242 is designed to remain occluding infusion set 230 until the pressure threshold is exceeded. Once deviated from the path, the wall cannot return to its original position, even after pressure drop. Due to the necessary increase in pressure to move the wall 242 generated by the pump (not shown), the infusion set 230 must have been correctly loaded into the pump for the wall to open. When the infusion set 230 is properly loaded into the pump, the pump will prevent free flow. Thus, if the infusion set 230 is loaded correctly into the pump, the occluder need not continue to prevent free flow.

Turning now to Figures 4A and 4B, fragmentary, side cross-sectional views of yet another example are shown to aid in understanding the present invention. An infusion set, indicated generally at 250 has an occluder 254 in the form of a duckbill valve formed therein to divide the infusion set 250 into an upstream proximal portion 250a and a downstream distal portion 250b. Occluder 254 is formed of two blades 258a and 258b that are skewed in engagement with each other.

When the pressure in the proximal portion 250a of the infusion set 250 is less than about 27.58 kPa (4 psi), the deflection of the paddles 258a and 258b keeps them in contact as shown in Figure 4A. Once the pressure in proximal portion 250a exceeds approximately 4 psi (27.58 kPa), the pressure forces valves 258a and 258b away from each other, thereby allowing an infusion liquid to flow through occluder 254. and in the distal portion 250b of the infusion set 250, as shown in Figure 4b. For the occluder 254 to work in such a manner, it is preferable that the blades 258a and 258b extend distally while engaging each other. However, the occluder 254 could be made so that the blades extend proximally and are then clamped once the pressure threshold has been exceeded.

Occluder 254 is shown as being integrally molded with infusion set 250. Such a configuration avoids any concern as to whether occluder 254 can move during use. However, it is also feasible to form an occluder 254 such as a separate unit and then place it in the infusion set 250. The occluder 254 could be held in place with adhesives or simply a friction fit.

Turning now to Figure 5A there is shown a fragmentary side cross-sectional view of an infusion set, indicated generally at 300, with an occluder 304 disposed therein. Similar to the embodiment shown in Figure 2A, the infusion set 300 is made from conventional silicone tubing or some other elastic or semi-elastic material, such as latex, polyurethane, etc.

Figure 5B shows a cross-sectional view of infusion set 300 and occluder 304 taken along plane AA in Figure 5A. As shown, the tube that defines the infusion set 300 forms a seal around the occluder 304 and prevents liquid from passing between the occluder and the tube that forms the infusion set.

Turning now to Figure 5C, a side cross-sectional view of the infusion set 300 and occluder 304 is shown. Disposed behind the infusion set 300 at the location of the occluder 304 is a wall 308. As will be explained in more detail further forward, wall 308, occluder 304, and infusion set 300 form a compression valve to selectively allow liquid to flow through the infusion set.

Figure 5D shows a cross-sectional view of infusion set 300 and occluder 304 taken along plane BB of Figure 5C. Infusion set 300 and occluder 304 are mounted between opposing walls 308 that are spaced a distance slightly less than the outside diameter of the infusion set. As the infusion set 300 is positioned between opposing walls 308, the sides of the tubes that make up the infusion set are compressed and held against the occluder 304. This compression also causes the upper and lower portions 300a and 300b of the tube extend radially outward from the occluder 304, thereby opening a flow path 312 above and below the occluder. Flow paths 312 allow liquid in infusion set 300 to flow around occluder 304 and flow into the patient.

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In the event that infusion set 300 and occluder 304 are removed from between opposing walls 308, the tube that forms infusion set 300 will return to the position shown in Figures 5A and 5B, thereby terminating flow. through the infusion set. Thus, the configuration shown in Figures 5A through 5D prevents the free flow of infusion set liquids through infusion set 300, provided the infusion set and occluder 304 are properly mounted between walls 308. (or some analogous mating surfaces). Infusion set 300 and occluder 304 are normally positioned between walls 308 as the infusion set is being loaded into the pump (not shown). Once properly loaded, the pump controls the flow through the infusion set 300 and prevents free flow.

Turning now to Figure 5E, there is shown a perspective view of an enteral feeding pump housing, indicated generally at 330, manufactured in accordance with one aspect of the present invention. Housing 330 includes a pair of channels 340 and 344 for the containment of a portion of an infusion set tubing, such as those described with respect to Figures 3A through 5D. During use, the tube is placed in a channel 340, wrapped around a motor unit (not shown) that is placed in the opening 350, and is then placed in the second channel 344. If a conventional infusion set is not Properly wrapped over the motor unit (or properly installed on other types of pumps) and placed in channels 340 and 344, a free-flow condition may develop. However, the present invention prevents such a situation from developing.

As shown in Figure 5E in dashed lines, infusion set 354 mounts to first and second channels 340 and 344. At least one portion 340a of channel 340 is narrow enough to form walls, similar to walls 308 of Figures 5A through 5D, which compress the sides of the tube that forms the infusion set 354, thereby creating a flow path around the occluder (not shown) in the infusion set. If desired, the entire length of the walls 360 that form the channel 340 could be close enough to each other to compress the infusion set 354 and thereby open the open flow.

Figure 5E also shows a cover 370 that connects to housing 330. Cover 370 is pivotable relative to housing 330 and includes a retainer 374 that engages a slot 380 in the housing. When cover 370 is closed and retainer 374 engages slot 380, infusion set 354 is held firmly in housing 330 and it is unlikely that the infusion set can be removed from the pump.

Instead of causing the walls 360 of the channel 344 to compress the sides of the infusion set 354 to form a compression valve with the sides of the infusion set 354, a projection 384 can be mounted on the cover 370 so that it is in alignment with the infusion set. When the cover is closed, the projection 384 applies a downward force on the infusion set 354 thereby forming an open compression valve with the flow channels being arranged in horizontal alignment, rather than vertical alignment as shown in Fig. Figure 5D. Therefore, the liquid flowing through infusion set 354 passes around the sides of the occluder, as opposed to above and below the occluder.

It will be appreciated in light of the present disclosure that when a projection is used to engage the occluder, the occluder does not have to be contained in a channel. Rather, the infusion set 354 can only be positioned on generally opposite sides in order to open at least one flow path around the occluder, or enough pressure must be exerted to cause the infusion set to expand and open a path. flow.

As long as retainer 374 in cover 370 engages slot 380 in housing 330, or projection 384 remains in engagement with infusion set 354 at the occluder location, the compression valve will remain open. If the cover 370 is opened, the force holding the compression valve open is removed and the infusion set 354 retracts to the closed position shown in Figures 5A and 5B, thereby preventing free flow through the infusion set. infusion 354.

Turning now to Figures 6A and 6B, the infusion set, generally indicated at 400, has an occluder 404 disposed therein. Occluder 404 can be molded into infusion set 400, or it can be separately constructed and inserted.

The occluder 404 is formed by a first blade 408a and a second blade 408b that form a duckbill valve. The blades 408a and 408b are arranged to extend proximally (ie, upstream). As shown in Figure 6A, paddles 408a and 408b normally engage each other to occlude flow from a proximal portion 400a of the infusion set 400 to a distal portion 400b of the infusion set.

When pressure is applied to the tubes that make up infusion set 400, paddles 408a and 408b move away from each other enough to allow fluid flow through the infusion set. Thus, in Figure 6, a compression valve is formed by sliding the infusion set 400 between two walls 412 of mating surfaces so that the paddles 408a and 408b are kept apart, or by forcibly engaging the infusion set. infusion with a projection or other structure associated with a door, etc. As long as the infusion set 400 remains between walls 412, projections, etc., fluid flow is enabled. If the portion of the infusion set 400 containing the occluder 404 protrudes from the walls 412 or projections, the

ES 2 550 797 T3 occluder will return to the closed position where it prevents free flow.

Preferably, infusion set 400 and occluder 404 will be used in a housing, such as that shown in Figure 5E. When the infusion set 400 is mounted in a channel defined by restricting side walls or when a cover with an aligned projection is closed, flow is activated through the infusion set. If the infusion set 400 is removed from the housing, the occluder 404 will automatically close - thereby preventing free flow through the infusion set.

The various embodiments described in accordance with the present invention provide a marked improvement over clamps and other types of external occluders that are commonly used to control fluid flow. These embodiments provide security against free flow, are generally easier to handle, and are much more cost effective than prior art external occluders.

In addition to being able to be used with housings and other fixed structures that cause the valve to open, most of the configurations described above can also be opened manually simply by squeezing the infusion set adjacent to the occluder to open a path around the occluder. The availability of manually opening the occluder / infusion set is desirable as it facilitates priming the infusion set with the liquid being infused. However, unlike many of the prior art occluders simply releasing the infusion set adjacent to the occluder is all that is required to terminate the flow.

Turning now to Figure 7, there is shown another configuration of an infusion set, indicated generally at 400, and an occluder, 404 manufactured in accordance with the principles of the present invention. The infusion set 400 is formed of an elongated tube 108 made of a flexible, elastic material, such as silicone rubber, latex, polyurethane, neoprene, or numerous similar materials. Typically, the elongated tube has an inside diameter of about 3.302 mm (0.130 inches).

The occluder 404 has an outside diameter that is slightly larger than the inside diameter of the tube that forms the infusion set 400, typically about 3.581 mm (0.141 inches). This causes a portion 408a of the tube to stretch slightly as it passes over the occluder 404.

Occluder 404 prevents flow through infusion set 400 based on gravity. Therefore, the exact size of the occluder 404 will depend on the material used to form the infusion set 400. In a presently preferred embodiment, infusion set 400 is formed from a tube made of silicone rubber, and occluder 404 is formed from a plastic cylinder (for example, acrylonitrile butadiene styrene (A.BS), acrylic (PMMA). ), polycarbonate, etc.) having an outer diameter of 3.581 mm (0.141 inches) and a length of approximately 7.163 mm (0.282 inches).

Because the occluder 404 is larger than the inside diameter of the infusion set 400, the solution that is only under the force of gravity will back up behind the occluder and will not pass. Once sufficient pressure is present - for example, the pressure produced by a pump - the walls of the infusion set will expand to allow fluid flow past the occluder 400 as described with respect to Figure 2A, etc.

While the embodiment shown in Figure 2A is spherical and the embodiment shown in Figure 7 is cylindrical, those skilled in the art will appreciate that numerous other embodiments could be used. For example, dashed line 412 illustrates an occluder that is bullet shaped. The occluders can also be egg-shaped, or any other shape that provides a stop for fluid flow up to a predetermined pressure threshold. It will also be appreciated that the occluder 404 need not have a constant diameter. By having a portion of the occluder 404 that extends radially a greater distance than other parts, a portion of the occluder will always engage the wall of the infusion set 400, thereby reducing the ability of the occluder to move within the infusion set.

Turning now to Figure 8, still another configuration of an infusion set 420 and occluder 424 manufactured in accordance with the principles of the present invention is shown. The infusion set 420 is formed from an elongated tube 428 having a first portion 432 and a second portion 436 that are connected to each other by a connector 440. Occluder 424 is attached to connector 440 by a tether 442 to prevent the occluder from advancing along second portion 436 of elongated tube 428.

When sufficient pressure is present in an upstream proximal portion 428a of elongated tube 428, second portion 432 will expand sufficiently to allow fluid flow to pass through occluder 424 and into the downstream distal portion 428b of the infusion set. 420. An advantage of using the connector is that the first portion 428a of the elongated tube 428 need not be formed of a material that is elastic, or can use a material that does not expand or contract consistently. In other words, less expensive tubing materials can be used for most of the infusion set 420 without interfering with the interaction between the infusion set and the occluder 424.

While shown in Figure 8 as generally spherical, it should be appreciated that occluder 424 could present

ES 2 550 797 T3 various forms. In addition, a single tether strap 442 or a plurality of tether straps could be used to hold the occluder 424 to the connector 440.

Figure 8A shows a cross-sectional view of another configuration of an infusion set 420, and an occluder 444. Unlike the spherical occluder 424 of Figure 8, the occluder 444 of Figure 8A is disc-shaped. To prevent occluder 444 from rotating in response to fluid pressure and inadvertently opening a fluid flow path, a plurality of tie straps 442 are used to secure disk 440 to the connector.

When sufficient pressure is present in infusion set 420, tube 428 will expand and allow fluid flow past occluder 444. Once the pressure drops below a predetermined threshold, tube 428 will reattach the occluder. 444 and the flow will end.

Figure 8B shows a cross-sectional view of yet another configuration of an occluder 446. The infusion set 420 and corresponding portions are the same as in Figures 8 and 8A and are numbered accordingly.

Connector 440 is attached by one or more tie straps 442 to occluder 446 to prevent the occluder from moving downstream. Tether straps 442 can also be used to hold occluder 446 in a desired orientation. When sufficient pressure is present, tube 436 expands to allow fluid flow past occluder 446.

Figure 9 shows yet another example in which the infusion set 450 and the occluder 454 form part of a liquid control valve, indicated generally at 460. In accordance with the embodiments described above, and in particular, the relative description 5A through 5E, occluder 454 normally prevents fluid flow through the infusion set. However, squeezing the infusion set on opposite sides of the side wall of the infusion set 450a causes other portions of the side wall to extend beyond the occluder 454 - as demonstrated in Figures 5C and 5D.

Disposed adjacent to infusion set 450 and occluder 454 are a pair of coupling members 464 that are in communication with an actuator 468, such as a motor. Communication can be electronic, mechanical, or pneumatic, as long as the actuator 468 can control the movement of one or more of the coupling members 464.

When the coupling elements are actuated, they apply an inward force to the infusion set 450 at the location of the occluder 454 to open a passageway around the occluder and thereby allow fluid flow through the infusion set. . When coupling members 464 are adjusted to no longer apply sufficient force to infusion set 450, the infusion set again surrounds occluder 454 and prevents fluid flow.

By selectively actuating coupling elements 464, infusion set 450, and occluder 454, a valve is formed to control fluid flow. By applying a pressure sensor or other type of sensor, the valve can be used to regulate the flow and the flow through the valve can be determined.

Turning now to Figure 10, there is shown a perspective view of a clamp, indicated generally at 480, for the flow port between an occluder and the infusion set. Those skilled in the art will appreciate that there are a number of enteral and parenteral pumps on the market that utilize different types of occluders that suffer from the problems identified in the background section. To eliminate these concerns, the clamp 480 is configured for retrofitting an existing pump for use with an occluder / infusion set manufactured in accordance with the principles of the present invention. (Of course, with some existing pumps, the occluder and infusion set may be configured to nest in the pump such that retrofitting is not necessary.)

Clip 480 includes a base 484 that is provided for attachment to a conventional fluid pump housing. Typically, the base 484 will have an adhesive disposed thereon. If desired, the adhesive may be selected from removable adhesives, such as those known to those skilled in the art, so that the clamp 480 can be removed from the pump when an infusion set containing an occluder (such as that represented by dashed lines 488) is not being used with the pump.

Extending from the base 484 is a fitting 490 that has the channel 492 formed therein. Channel 492 is preferably formed with an open end and extends into clip 480. As the infusion set, shown shaded at 488, is inserted into the channel 492, the walls 494 defining the channel compress the infusion set 488 against the occluder (shown as dashed lines 498) to open a pair of channels of flow between the occluder and the infusion set as shown in Figures 5A to 5D.

While infusion set 488 and occluder 498 remain securely contained between walls 494 defining channel 492, fluid flow is enabled between the occluder and infusion set. If the infusion set 488 is removed from channel 492 or is never positioned correctly in the channel, the flow through the infusion set will be

ES 2 550 797 T3 avoid. Therefore, the risk of free-flow development within the system is significantly reduced. Of course, the risk of free flow can be practically eliminated by positioning the clamp 480 on the pump such that the infusion set 488 must be properly loaded into the pump in order to fit within the channel 492.

Figure 11 shows a cross-sectional side view of yet another example forming an in-line pump, generally indicated at 500. As shown in Figure 11, a pair of occluders 504 and 508 are arranged in an infusion line 512. Each of occluders 504 and 508 is disposed adjacent to an actuator 514 and 518, respectively. Actuators 514 and 518 are configured to selectively apply pressure to infusion line 512 to selectively open flow channels between the infusion line and the occluder 504 or 508 with which each is associated.

During use, the liquid in the infusion line 512 will remain in a proximal portion 512a that is upstream of the first occluder 504. The first occluder 504 prevents the liquid from flowing downstream until an actuation mechanism 522 causes the first actuator 514 applies a force to infusion line 512 adjacent to the first occluder. Applying a force to the infusion line 512 causes a channel to open between the first occluder 504 and the infusion line, allowing fluid flow into an intermediate portion 512b of the infusion line.

Once the intermediate portion 512b of the infusion line 512 has had sufficient time to fill with liquid, the actuator 514 is adjusted so that it no longer applies sufficient force to the infusion line to allow fluid flow around the occluder. 504. The liquid in the intermediate portion 512b of the infusion line 512 is isolated from the liquid in the proximal portion 512a.

Liquid in the intermediate portion 512b of the infusion line 512 is prevented from flowing distally or downstream through the second occluder 508 that defines the distal end of the intermediate portion. However, once drive mechanism 522 is actuated to move actuator 518 into forceful contact with infusion line 512 adjacent to occluder 508, one or more channels are formed between the occluder and the infusion line. The channel or channels opened by actuator 518 that squeezes infusion line 512 form a flow path allowing liquid contained in intermediate portion 512b to flow to a downstream distal portion 512c. Since no occluder or other stopper is normally distally distal from second occluder 508, liquid flowing into distal portion 512c is delivered to the patient.

By selectively controlling the application of force by the first actuator 514 on the infusion line 512 and the first occluder 504 and the application of force by the second actuator on the infusion line and the second occluder 508, a valve is formed, generally indicated at 526, which allows a predetermined amount of flow to pass with each series of actuations.

In a more preferred embodiment, the valve also includes a force applicator 530, such as a plunger, roller, or similar device, disposed in communication with the intermediate portion 512b of the infusion line 512. The force applicator 530 applies a force of compression to the intermediate portion 512b of the infusion line 512 to force the liquid contained in the intermediate portion 512b to flow into the distal portion 512c of the infusion line 512 and into the patient. Force applicator 530 ensures that liquid does not simply remain in intermediate portion 512b when second actuator 518 causes a flow path to form between second occluder 508 and infusion line 512.

While applying a compressive force to the intermediate portion 512b of the infusion line 512 helps to force the liquid in the intermediate portion to flow downstream, it also serves to aid flow in the intermediate portion. Once a compressive force is no longer applied to the intermediate portion 512b, the elastic material that forms the infusion line will attempt to return to its original tubular configuration. By closing the flow path between the second occluder 508 and the infusion line 512 prior to releasing the force applicator 530, a vacuum is formed within the intermediate portion 512b. Once the actuator 514 opens a flow path between the first occluder 504 and the infusion line 512, the vacuum in the intermediate portion 512b will draw the liquid in the intermediate portion 512b as the infusion line returns to its original configuration. .

At each cycle of valve 526, first actuator 514 will open a flow channel between first occluder 504 and infusion line 512 to fill intermediate portion 512b with liquid. The first actuator 514 will then allow the flow channel to close. The second actuator 518 will then open a flow channel between the second actuator 508 and the infusion line 512 and the force applicator 530 will apply pressure to the infusion line that forms the intermediate portion 512b so that the liquid in the intermediate portion will flow. at distal 512c and toward the patient. The second actuator 518 will then allow the flow channel between the second occluder 508 and the infusion line 512 to close. The process is then repeated.

By controlling the inside diameter of the infusion line 512, the distance between the first occluder 504 and the second occluder 508, and the movement / size of the force applicator 530, a predetermined amount of liquid flow can be obtained with each cycle of valve 526. By controlling the number of cycles in a period of time

ES 2 550 797 T3 predetermined, the operator is able to provide a very accurate flow rate for the solution passing through valve 526. Also, due to a rotor it is not necessary to control the flow rate, valve 526 is you can use to make an in-line peristaltic pump that is significantly finer than conventional peristaltic pumps while maintaining the same precision.

While Figure 11 shows two actuators, those skilled in the art will understand, in light of the present invention, that one of the occluders could be configured to allow fluid flow in response to force if properly configured to prevent interference. return flow. This could be achieved, for example, by controlling the size of the occluders.

Turning now to Figure 12A, there is shown a perspective view of a pump, generally indicated at 600, that is designed to control the flow of fluid through an infusion set, generally indicated at 604, and into the patient. Pump 600 includes a control panel 608 having a plurality of buttons 610 or other devices for controlling actuation of the pump. Pump 600 operates to deliver a predetermined dose of enteral feeding solution to a patient by rotating a rotor 612.

The infusion set 604 is mounted on the pump such that an elastic portion 604a of the infusion set wraps around the rotor 612. Each turn or partial turn of the rotor 612 causes a predetermined amount of enteral feeding solution to advance through infusion set 604 and delivered to the patient.

In order to ensure that the rotor 604 is providing the proper amount of enteral feeding solution, a drip chamber 620 is formed along the infusion set. An optical sensor 624 is disposed on enteral feeding pump 600 and controls the drip rate of the solution into drip chamber 624. The drip rate of the solution is used to calculate an actual delivery rate of the solution.

As with the prior art, an infusion set portion 604b distally from rotor 612 nests in a channel 630 in pump housing 600. In accordance with the present invention, portion 604b has an occluder 634 disposed at its interior. Although the prior art simply uses channel 630 to hold infusion set 604 in contact with rotors, the inclusion of an occluder 634 provides an improved measure of security.

In the prior art, although portion 604b of infusion set 604 is not positioned correctly in channel 630, a free-flow condition could develop in which fluid flow through the infusion set would not be checked by the rotor 612. In the present invention, flow through infusion set 604 is not allowed until portion 604b with occluder 634 nests in channel 630. If portion 604b of infusion set 604 is not correctly positioned in channel 630 or is removed from the channel, occluder 630 will prevent free flow through the infusion set.

Figure 12B shows an embodiment of the invention and a close-up cross-sectional view of the portion of pump 600 having channel 630 formed therein taken along line AA. Channel 630 receives infusion set 604 such that tube 642 is compressed against occluder 634. This causes another portion of tube 642 to extend away from occluder 634 and thereby opens a fluid flow path between the inner wall of the tube and the occluder.

As shown in Figure 5D, compression from opposite sides of the infusion set can open the fluid flow channels above and below the occluder. In Figure 12B, tube 642 of infusion set 604 is pressed against one half of occluder 634, thus forming a single fluid flow channel 646 on the opposite side. If portion 604b of infusion set 604 containing occluder 634 is removed from channel 630, the infusion set will engage the occluder and prevent fluid flow.

Turning now to Figure 13A, a connector is shown. The connector 700 is formed by an adapter body 708 that is used to connect pieces of tubing together. Most commonly, adapter body 708 is used to connect a segment of silicone tubing that couples the pump rotor to the remaining tubing of an infusion set (not shown). Such connectors 700 are used in various infusion sets currently in use.

The adapter body 708 is formed of a proximal section 712, a distal section 716, and an annular flange 718 that limits the advancement of the tubes from the proximal and / or distal sections of the adapter body. The proximal section 712 normally mates with the silicone tubing, while the distal section 716 mates with the remaining tubing of the infusion set.

An arm 720 that forms a retainer / retractor strap extends proximally from proximal portion 712, and maintains an occluder 724 at a separate distance from the remainder of adapter 708. Unlike the previous embodiments described above, occluder 724 has a generally teardrop shape when adapter 708 is stopped at the end. As shown in Figure 13a, the distal end 724a of the occluder 724 can be rectangular. However, it can also be rounded or have another contoured shape. In light of the embodiments described above, those skilled in the art will appreciate that a diamond-shaped occluder

ES 2 550 797 T3 spherical or otherwise could be used as well.

Unlike the clamping arrangements described in previous embodiments, arm 720 holds occluder 724 generally rigidly and proximally from the adapter. In the event that arm 720 was broken by undue flexing of the infusion set in which adapter body 708 is mounted, occluder 724 would not be able to move downstream in the infusion set. In contrast, the adapter body 708 would prevent distal movement and arm position and the shape of the occluder 724 would prevent the occluder from completely blocking flow through the tube, as long as the designated pressures are used to adequately expand the tube.

Turning now to Figure 13B, a cross-sectional view of the connector 700 shown in Figure 13A is shown. This view shows the two flow channels 730 that are formed on either side of the arm 720. The two flow channels 730 are configured to allow fluid that had flowed past the occluder 724 to enter the hollow channel 734 of the adapter body 708 and flow downstream of the occluder. An end view of connector 700 is shown in Figure 13C.

The opening at the proximal end of proximal section 712 is preferably approximately 2.489mm (0.098 inches) in diameter and is traversed by arm 720 which is approximately 0.762mm (0.03 inches) thick. Occluder 724 is preferably spaced approximately 2.159 mm (0.085 inches) apart from proximal section 712, and is provided with a 0.635 mm (0.025 inches) radius of curvature at the leading end. The rounded portion of the distal end is typically about 0.762 mm (0.03 inches) long.

The spacing of the occluder 724 from the proximal section 712 and the size of the flow channels 730 are sufficient to allow fluid to flow easily through the connector 700 if the pressure is greater than about 34.47 kPa (5 psi). If pressures are below approximately 34.47 kPa (5 psi), occluder 724 will prevent fluid flow through connector 700.

Making the occluder 724 part of the connector 700 has several distinct advantages. First, it has been found that the occluder 724 can be added simply by modifying existing molds. Therefore, rather than having to design a completely new product, infusion set manufacturers can easily retrofit their existing molds to add the 724 occluder. The cost of mold adaptation is almost negligible. Additionally, the amount of additional plastic that is used to form the occluder raises the cost of producing connector 700 by a mere fraction of a penny. This is in contrast to currently available compression clamp clamps and occluders which can cost from ten to twenty cents, and constitutes more than ten percent of the infusion set cost. Therefore, for almost no cost, the infusion set can be provided with a highly reliable anti-free flow device.

Figures 13D and 13E show the pumps described in Figures 5E and 12A, respectively. To avoid excessive repetition, the pumps are portions of the pumps that are similar to those in the drawings are labeled accordingly.

As shown in Figures 13D and 13E, the connector 700 is preferably mounted on the infusion pump downstream from the pump rotor 750 (Figure 13D) and 760 (Figure 13E). As the rotor of the 750/760 pump rotates, it will create enough pressure to cause the fluid being pumped to pass past the occluder 724 and into the channel 734 (Figure 13B) at the connector 700. The fluid is then free to flow downstream.

Connector 700 is highly advantageous because it can be used in most infusion pumps without the need to install accessories or otherwise modify the infusion set. Eliminates the need to recess an occluder, as shown in number 630/634 on the pump shown in Figure 12A, and eliminates the need for modified channels 340 / 340a or a 384 projection as described with with respect to Figure 5A. When mounted on the infusion set, the connector 700 appears substantially the same as the conventional connector and the patient may not even know that it is used unless instructed to do so.

However, the advantages of conventional compression forceps occluders, etc., are achieved without drawbacks.

Therefore, an improved apparatus and method for preventing free flow in an infusion line is disclosed. The apparatus and method can be used with infusion control pumps, such as enteral feeding pumps or IV pumps, or as a replacement for such pumps. While the present description discloses presently preferred embodiments, those skilled in the art will appreciate numerous modifications that can be made without departing from the scope and spirit of the present invention. For example, the relative size of the infusion set and the occluder could be changed by providing an occluder that shrinks sufficiently under pressure to create fluid flow paths. The appended claims are intended to cover such modifications.