Free flow prevention system for infusion pump

• US 5,437,642 A
• Filed: 06/01/1993
• Issued: 08/01/1995
• Est. Priority Date: 04/23/1991
• Status: Expired due to Fees

• Current Assignee: Graseby Medical Limited (ICU Medical Incorporated)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Toycen, Mark A., Struble, Kent R., Thill, Gary A., Curran, Timothy G.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): STRIGHT, RONALD K
• Application Number:
  US08/070,497
• Time in Patent Office: 791 Days
• Field of Search: 128/DIG. 12, 128/DIG. 13, 128/685, 128/686, 604/30, 604/31, 604/34, 604/150, 604/151, 604/153, 604/131, 604/245, 604/246, 604/250, 251/4, 251/7, 251/10, 251/9, 417/474, 417/475, 417/477 A, 417/477 R, 417/478, 417/479, 417/480, 417/497, 417/510
• US Class Current: 604/153
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 39/281 Automatic tube cut-off devices, e.g. squeezing tube on detection of air
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: Y10S 128/12 Pressure infusion
• CPC Class Codes: Y10S 128/13 Infusion monitoring

Abstract

A free flow prevention system for preventing undesired free flow of fluid through IV tubing of the type used in an infusion pump. The system comprises a spring clip having a base and a spring arm defining a channel adapted to receive the IV tubing. The spring arm is resiliently biased to a closed position in which the IV tubing is squeezed by the spring clip to close the lumen to prevent fluid flow, and the spring arm is movable against the bias to an open position wherein the lumen of the IV tubing is allowed to open to allow flow. The system also includes a clip-opening pin in the infusion pump for moving the spring arm of the clip from its closed position to the open position. The clip-opening pin is movable relative to the spring clip to move the spring arm between an unloading position, in which the clip-opening pin does not hold the spring arm in its open position, and an operating position, in which the clip-opening pin moves the spring arm to its open position and holds the spring arm in the open position.

Claims

1. An IV tubing set through which fluid flow is regulated by an infusion pump of the type used to regulate fluid being delivered to a patient;

the IV tubing set comprising;

IV tubing having a lumen through which fluid may be pumped for administration to a patient, the IV tubing including a pumping cassette having at least two flexible walls having inner surfaces defining fluid pumping chambers therebetween, the pumping chambers defining a portion of the lumen, the flexible walls defining a flange extending from the fluid pumping chambers and terminating in a peripheral edge of the pumping cassette, and further defining opposite outwardly-facing major surfaces of the pumping cassette; and

a spring clip mounted on the flange of the pumping cassette and having a base and a spring arm extending therefrom along the opposite major surfaces of the pumping cassette and across the lumen, the spring arm being resiliently biased to a closed position in which the pumping cassette is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the lumen of the pumping cassette is allowed to open to allow flow through the lumen;

the spring clip further comprising detent means for releasably holding the spring arm against its normal spring biasing force in a priming position in which the lumen of the IV tubing is open to allow flow through the lumen.

2. An IV tubing set according to claim 1 wherein the spring arm is spaced farther from the base in the priming position than in the open position.

3. An IV tubing set according to claim 2 wherein the spring arm has a free end, the detent means comprising a latching arm extending from the base of the spring clip adapted to engage the free end of the spring arm to hold the spring arm in its priming position.

4. An IV tubing set according to claim 3 wherein the detent means further comprises complementary bends in the latching arm and spring arm adapted to engage each other to hold the spring arm in its priming position.

5. An IV tubing set according to claim 4 wherein the complementary bends of the latching arm and spring arm include a concave bend on the free end of the spring arm with its concave surface facing the latching arm, and a convex bend on the latching arm complementary to the spring arm with its convex surface adapted for engagement with the concave surface of the spring arm to hold the spring arm in its priming position.

6. An IV tubing set according to claim 5 adapted to be used in an infusion pump having a clip-opening pin for moving the spring arm of the IV tubing set from its closed to its open position to allow fluid flow through the IV tubing set;

the base of the spring clip defining a longitudinal direction and the spring arm is movable in a lateral plane defined by the base and spring arm between the priming, open and closed positions, the direction of movement of the spring arm from the priming position toward the closed position constituting the laterally inward direction;

the spring arm extending from generally adjacent one end of the base generally longitudinally along the base toward the latching arm and terminating in its free end generally adjacent the latching arm, the spring arm having a bent portion connecting the spring arm to the base including a first portion bent laterally outwardly from the base, a second portion bent laterally inwardly from the first position and extending generally longitudinally along the base when the spring arm is in its closed position, and a third portion bent laterally inwardly from the second portion, the spring arm having a main section bent laterally outwardly from the third portion and extending in the direction generally parallel with the second portion of the spring arm;

the free end of the spring arm having a detent portion bent laterally inwardly from the main portion and adapted for sliding engagement with the latching arm, the detent portion including the concave bend, the free end of the spring arm also including a tab portion bent from the detent portion and adapted to be engaged by the clip-opening pin of the infusion pump to move the spring arm from its closed position to its open position, the tab portion extending in a direction generally parallel to the longitudinal direction when the spring arm is in its closed position, the concave bend of the detent portion being generally adjacent the tab portion; and

the latching arm including a first section extending from the other end of the base generally longitudinally along the base, and a second section bent laterally outwardly from the first section, the second section including the convex bend that is complementary to the concave bend of the spring arm.

18. A system according to claim 1 wherein the peripheral edges of the pumping cassette include opposite lateral edges extending along opposite sides of the lumen, and the flange of the pumping cassette has opposed slots extending inwardly toward each other along the opposite outwardly-facing major surfaces from opposite lateral edges of the pumping cassette, the spring clip being held in position across the lumen of the pumping cassette by the opposed slots.

7. A free flow prevention system comprising:

an IV tubing set comprising;

IV tubing having a lumen through which fluid may be pumped for administration to a patient; and

a spring clip having a base and a spring arm extending therefrom, the base and spring arm defining a channel adapted to receive a portion of the IV tubing, the spring and being resiliently biased to a closed position in which the IV tubing is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the lumen of the IV tubing is allowed to open to allow flow through the lumen, the spring clip further comprising detent means for releasably holding the spring arm against its normal spring biasing force in a priming position in which the lumen of the IV tubing is open to allow flow through the lumen; and

an infusion pump for controlling infusion of a fluid through the IV tubing, the infusion pump comprising;

pumping means for pumping fluid through the IV tubing;

releasable holding means for releasably holding the IV tubing during operation of the infusion pump;

clip-receiving means for releasably receiving the clip in the infusion pump; and

clip-opening means for moving the spring arm of the clip from its closed position to the open position;

the clip-receiving means and the clip-opening means being mounted on the infusion pump for movement of the clip-opening means relative to the clip received by the clip-receiving means between an unloading position, in which the clip-opening means does not hold the spring arm in its open position and an operating position, in which the clip-opening means moves the spring arm to its open position and holds the spring arm in the open position;

the clip-opening means comprising a clip-opening pin mounted in the infusion pump for engagement with the spring arm of the spring clip, the pin and the spring clip being movable relative to one another between the operating position, in which the pin engages the spring arm to hold the spring arm in its open position, and the unloading position, in which the pin is not holding the spring arm in its open position so that the spring arm is allowed to move to its closed position to close the lumen of the IV tubing;

the releasable holding means including a door mounted on the infusion pump, the clip-receiving means including walls within the door defining a recess for receiving the spring am of the spring clip and allowing movement of the spring arm between its open and closed positions;

the system further comprising release means in the door for releasing the detent means before operation of the infusion pump so that the spring arm moves from its priming position toward the open and closed positions;

the door having open and closed positions, the release means comprising a resilient release spring mounted in the recess of the door and adapted to engage the spring arm to release the detent means and move the spring arm to the closed position when the door is moved to its closed position, the clip-opening pin being adapted to move the spring arm against the bias of the release spring when the clip-opening pin and releasable holding means are in their operating position.

8. A system according to claim 7 wherein the spring arm is spaced farther from the base in the priming position than in the open position, the release spring being adapted to move the spring arm toward the base when the door is moved to its closed position.

9. A system according to claim 8 wherein the spring arm has a free end, the detent means comprising a latching arm on the base of the spring clip adapted to engage the free end of the spring arm to hold the spring arm in its priming position.

10. A system according to claim 9 wherein the detent means further comprises complementary bends in the latching arm and spring arm adapted to engage each other to hold the spring arm in its priming position.

11. A system according to claim 10 wherein the complementary bends of the latching arm and spring arm include a concave bend on the free end of the spring arm with its concave surface facing the latching arm, and a convex bend on the latching arm complementary to the spring arm with its convex surface adapted for engagement with the concave surface of the spring arm to hold the spring arm in its priming position.

12. A system according to claim 11 wherein the IV tubing includes a pumping cassette having flexible walls defining fluid pumping chambers that may be compressed by the pumping means to regulate fluid flow through the IV tubing, the door being adapted to hold the pumping cassette in the infusion pump.

13. A system according to claim 12 wherein the spring clip is formed from a flat sheet of resilient metal cut and bent to form the spring arm, latching arm and base of the spring clip.

14. A free flow prevention system comprising:

an IV tubing set comprising;

IV tubing having a lumen through which fluid may be pumped for administration to a patient, the IV tubing including a pumping cassette having at least two flexible walls defining fluid pumping chambers therebetween and a flange extending from the fluid pumping chambers and terminating in a peripheral edge of the pumping cassette, the pumping chambers defining a portion of the lumen, the flexible walls also defining opposite outwardly-facing major surfaces of the pumping cassette; and

a spring clip mounted on the flange of the pumping cassette and having a base and a spring arm extending therefrom along the opposite major surfaces of the pumping cassette and across the lumen, the spring arm being resiliently biased to a closed position in which the pumping cassette is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the lumen of the pumping cassette is allowed to open to allow flow through the lumen; and

an infusion pump for controlling infusion of a fluid through the IV tubing, the infusion pump comprising;

pumping means for pumping fluid through the pumping cassette;

releasable holding means for releasably holding the pumping cassette during operation of the infusion pump;

clip-receiving means for releasably receiving the clip in the infusion pump; and

clip-opening means for moving the spring arm of the clip from its closed position to the open position;

the clip-receiving means and the clip-opening means being mounted on the infusion pump for movement of the clip-opening means relative to the clip received by the clip-receiving means between an unloading position, in which the clip-opening means does not hold the spring arm in its open position, and an operating position, in which the clip-opening means moves the spring arm to its open position and holds the spring arm in the open position.

15. A system according to claim 14 wherein the clip-opening means comprises a clip-opening pin mounted in the infusion pump for engagement with the spring arm of the spring clip, the pin and the spring clip being movable relative to one another between the operating position, in which the pin engages the spring arm to hold the spring arm in its open position, and the unloading position, in which the pin is not holding the spring arm in its open position so that the spring arm is allowed to move to its closed position to close the lumen of the IV tubing.

16. A system according to claim 15 wherein the clip-receiving means is mounted on or formed in the releasable holding means, the releasable holding means being movable to move the clip-holding means relative to the pin between the unloading and operating positions.

17. A system according to claim 15 wherein the releasable holding means includes a door mounted on the infusion pump, the clip-receiving means including walls within the door defining a recess for receiving the spring arm of the spring clip and allowing movement of the spring arm between its open and closed positions.

19. A free flow prevention system comprising:

an IV tubing set comprising;

IV tubing having a lumen through which fluid may be pumped for administration to a patient; and

a spring clip having a base and a spring arm extending therefrom, the base and spring arm defining a channel adapted to receive a portion of the IV tubing, the spring arm being resiliently biased to a closed position in which the IV tubing is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the spring arm is spaced from the base of the spring clips such that the lumen of the IV tubing is allowed to open to allow flow through the lumen, the spring clip further comprising detent means for releasably holding the spring arm against its normal spring biasing force in a priming position in which the spring arm is farther spaced from the base of the spring clip than in the open position and the lumen of the IV tubing is open to allow flow through the lumen; and

an infusion pump for controlling infusion of a fluid through the IV tubing, the infusion pump comprising;

pumping means for pumping fluid through the IV tubing;

releasable holding means for releasably holding the IV tubing during operation of the infusion pump;

clip-receiving means for releasably receiving the clip in the infusion pump; and

clip-opening means for moving the spring arm of the clip from its closed position to the open position;

the clip-receiving means and the clip-opening means being mounted on the infusion pump for movement of the clip-opening means relative to the clip received by the clip-receiving means between an unloading position, in which the clip-opening means does not hold the spring arm in its open position, and an operating position, in which the clip-opening means moves the spring arm to its open position and holds the spring arm in the open position;

the clip-opening means comprising a clip-opening pin mounted in the infusion pump for engagement with the spring arm of the spring clip, the pin and the spring clip being movable relative to one another between the operating position, in which the pin engages the spring arm to hold the spring arm in its open position, and the unloading position, in which the pin is not holding the spring arm in its open position so that the spring arm is allowed to move to its closed position to close the lumen of the IV tubing;

the releasable holding means including a door mounted on the infusion pump, the clip-receiving means including walls within the door defining a recess for receiving the spring arm of the spring clip and allowing movement of the spring arm between its open and closed positions.

20. A system according to claim 19 further comprising release means in the door for releasing the detent means before operation of the infusion pump so that the spring arm moves from its priming position toward the open and closed positions.

21. An infusion pump for regulating fluid flow through a lumen of an IV tubing set to a patient, the IV tubing set being of the type including a spring clip having a base and a spring arm extending therefrom, the base and spring arm defining a channel adapted to receive a portion of the IV tubing, the spring arm being resiliently biased to a closed position in which the IV tubing is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the lumen of the IV tubing is allowed to open to allow flow through the lumen, the spring clip including detent means for releasably holding the spring arm of the spring clip against its normal spring biasing force in a priming position in which the lumen of the IV tubing is open to allow flow through the lumen;

the infusion pump comprising;

pumping means for pumping fluid through the IV tubing;

releasable holding means adapted for releasably holding the IV tubing during operation of the infusion pump;

clip-receiving means adapted for releasably receiving the spring clip in the infusion pump; and

clip-opening means adapted for moving the spring arm of the spring clip from its closed position to the open position;

the clip-receiving means and the clip-opening means being mounted on the infusion pump for movement of the clip-opening means relative to the clip received by the clip-receiving means between an unloading position, in which the clip-opening means does not hold the spring arm in its open position, and an operating position, in which the clip-opening means moves the spring arm to its open position and holds the spring arm in the open position;

the clip-opening means comprising a clip-opening pin mounted in the infusion pump for engagement with the spring arm of the spring clip, the pin and the clip-receiving means being movable relative to one another between the operating position, in which the pin is adapted to engage the spring arm to hold the spring arm in its open position, and the unloading position, in which the pin is adapted not to hold the spring arm in its open position so that the spring arm is allowed to move to its closed position to close the lumen of the IV tubing;

the releasable holding means including a door mounted on the infusion pump, the clip-receiving means including walls within the door defining a recess adapted for receiving the spring arm of the spring clip and allowing movement of the spring arm between its open and closed positions;

the infusion pump further comprising release means in the door adapted for releasing the detent means before operation of the infusion pump so that the spring arm moves from its priming position toward the open and closed positions;

the door having open and closed positions, the release means comprising a resilient release spring mounted in the recess of the door and adapted to engage the spring arm of the spring clip to release the detent means and move the spring arm to the closed position when the door is moved to its closed position, the clip-opening pin being adapted to move the spring arm against the bias of the release spring when the clip-opening pin and releasable holding means are in their operating position.

22. An infusion pump according to claim 21 adapted for use with an IV tubing set of the type including a pumping cassette having flexible walls defining fluid pumping chambers that may be compressed by the pumping means to regulate fluid flow through the IV tubing;

the releasable holding means of the infusion pump including cassette-receiving means adapted for receiving the pumping cassette, the door constituting a part of the cassette-receiving means, the pumping means including means adapted for compressing the pumping chambers of the pumping cassette to regulate fluid flow through the IV tubing set.

23. An IV tubing set through which fluid flow is regulated by an infusion pump of the type used to regulate fluid being delivered to a patient;

the IV tubing set comprising;

IV tubing having a lumen through which fluid may be pumped for administration to a patient, the IV tubing including a pumping cassette having at least two flexible walls having inner surfaces defining fluid pumping chambers therebetween, the pumping chambers defining a portion of the lumen, the flexible walls defining a flange extending from the fluid pumping chambers and terminating in a peripheral edge of the pumping cassette, and further defining opposite outwardly-facing major surfaces of the pumping cassette; and

a spring clip mounted on the flange of the pumping cassette and having a base and a spring arm extending therefrom along the opposite major surfaces of the pumping cassette and across the lumen, the spring arm being resiliently biased to a closed position in which the pumping cassette is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the lumen of the pumping cassette is allowed to open to allow flow through the lumen.

24. An IV tubing set according to claim 23 wherein the peripheral edges of the pumping cassette include opposite lateral edges extending along opposite sides of the lumen, and the flange of the pumping cassette has opposed slots extending inwardly toward each other along the opposite outwardly-facing major surfaces from the opposite lateral edges of the pumping cassette, the spring clip being held in position across the lumen of the pumping cassette by the opposed slots.

25. An IV tubing set through which fluid flow is regulated by an infusion pump of the type used to regulate fluid being delivered to a patient, the infusion pump having pumping means for regulating fluid flow through the tubing set;

the IV tubing set comprising;

IV tubing having a lumen through which fluid may be pumped for administration to a patient; and

a spring clip having a base and a spring arm extending therefrom, the base and spring and defining a channel adapted to receive a portion of the IV tubing, the spring arm being resiliently biased to a closed position in which the IV tubing is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position wherein the lumen of the IV tubing is allowed to open to allow flow through the lumen, the spring arm being spaced farther from the base in the priming position than in the open position, the spring arm having a free end;

the spring clip further comprising detent means for releasably holding the spring arm against its normal spring biasing force in a priming position in which the lumen of the IV tubing is open to allow flow through the lumen, the detent means comprising a latching arm extending from the base of the spring clip adapted to engage the free end of the spring arm to hold the spring arm in its priming position, the detent means further comprising complementary bends in the latching arm and spring arm adapted to engage each other to hold the spring arm in its priming position;

the IV tubing including a pumping cassette having at least two flexible walls having inside surfaces defining fluid pumping chambers therebetween, the pumping chambers defining a portion of the lumen, the flexible walls further defining a flange extending from the fluid pumping chambers and terminating in a peripheral edge of the pumping cassette, the flexible walls further having outer major surfaces defining opposite outwardly-facing major surfaces of the pumping cassette, the pumping chambers being adapted to be compressed by the pumping means of the infusion pump to regulate fluid flow through the lumen of the IV tubing, the spring arm and base of the spring clip being mounted on the flange of the pumping cassette.

26. An IV tubing set according to claim 25 wherein the pumping cassette has two openings or slots through the opposite surfaces thereof, arranged along opposite sides of the lumen and sealed with respect to the lumen to prevent fluid communication between the openings or slots and the lumen, the base of the spring clip extending along one surface of the pumping cassette between the two openings or slots, the spring arm extending from the base through one of the openings or slots and along the pumping cassette toward the other opening or slot such that the spring arm engages the pumping cassette when in its closed position to close the lumen to fluid flow, and the latching arm of the spring clip extending from the base through the other opening or slot.

27. An IV tubing set according to claim 25 wherein the spring clip is formed from a flat sheet of resilient metal cut and bent to form the spring arm, latching arm and base of the spring clip.

28. A spring clip for preventing undesired free flow of fluid through IV tubing of the type having a lumen through which fluid flow is regulated by an infusion pump having pumping means to regulate fluid being delivered to a patient, the spring clip comprising a base and a spring arm extending therefrom, the base and spring arm defining a channel adapted to receive a portion of the IV tubing, the spring arm being resiliently biased to a closed position in which the IV tubing is squeezed between the spring arm and the base of the clip to close the lumen to prevent fluid flow, the spring arm being movable against its normal biasing force to an open position in which the lumen of the IV tubing is allowed to open to allow flow through the lumen, the spring clip further comprising detent means for releasably holding the spring arm against its normal spring biasing force in a priming position in which the spring arm is spaced farther from the base in the priming position than in the open position so that the lumen of the IV tubing is open to allow flow through the lumen;

the spring arm having a free end, the detent means comprising a latching arm on the base of the spring clip adapted to engage the free end of the spring arm to hold the spring arm in its priming position;

the detent means further comprising complementary bends in the latching arm and spring arm adapted to engage each other to hold the spring arm in its priming position;

the base of the spring clip defining a longitudinal direction and the spring arm is movable in a lateral plane defined by the base and spring arm between the priming, open and closed positions, the direction of movement of the spring arm from the priming position toward the closed position constituting the laterally inward direction;

the complementary bends of the latching arm and spring arm including a concave bend on the free end of the spring arm with its concave surface facing the latching arm, and a convex bend on the latching arm complementary to the spring arm with its convex surface adapted for engagement with the concave surface of the spring arm to hold the spring arm in its priming position;

the spring arm extending from generally adjacent one end of the base generally longitudinally along the base toward the latching arm and terminating in its free end generally adjacent the latching arm, the spring arm having a bent portion connecting the spring arm to the base including a first portion bent laterally outwardly from the base, a second portion bent laterally inwardly from the first portion and extending generally longitudinally along the base when the spring arm is in its closed position, and a third portion bent laterally inwardly from the second portion, the spring arm having a main section bent laterally outwardly from the third portion and extending in the direction generally parallel with the second portion of the spring arm;

the free end of the spring arm having a detent portion bent laterally inwardly from the main portion and adapted for sliding engagement with the latching arm, the detent portion including the concave bend, the free end of the spring arm also including a tab portion bent from the detent portion and adapted to be engaged by a clip-opening pin in the infusion pump to move the spring arm from its closed position to its open position, the tab portion extending in a direction generally parallel to the longitudinal direction when the spring arm is in its closed position, the concave bend of the detent portion being generally adjacent the tab portion; and

the latching arm including a first section extending from the other end of the base generally longitudinally along the base, and a second section bent laterally outwardly from the first section, the second section including the convex bend that is complementary to the concave bend of the spring arm.

29. A spring clip according to claim 28 wherein the spring clip is formed from a flat sheet of spring steel cut and bent to form the spring arm, latching arm and base of the spring clip.