Unitary molded elastomer conduit for use with a medical infusion pump

• US 6,203,528 B1
• Filed: 03/30/1999
• Issued: 03/20/2001
• Est. Priority Date: 03/06/1995
• Status: Expired due to Fees

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Deckert, Clinton L., Maerzke, James T., Brown, Jeffrey P.
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US09/281,236
• Time in Patent Office: 721 Days
• Field of Search: 604/30, 604/31, 604/32, 604/33, 604/34, 604/65, 604/66, 604/67, 604/131, 604/153, 417/474, 417/477.1, 417/477.2, 417/477.3, 417/477.5
• US Class Current: 604/131
• CPC Class Codes: A61M 2205/14 Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 39/08 Tubes; Storage means specially adapted therefor
• CPC Class Codes: A61M 39/281 Automatic tube cut-off devices, e.g. squeezing tube on detection of air
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14232 Roller pumps
• CPC Class Codes: A61M 5/365 Air detectors A61M5/1684 takes precedence; in extracorporeal blood circuits A61M1/3626

Abstract

A unitary molded elastomer conduit for use with a medical infusion pump. The molded conduit includes a plurality of elongated tubular sections defining a continuous lumen therethrough. A first interior surface of the molded conduit includes an interior region having surface characteristics for clamping off the lumen to stop the flow of fluid transport, or for clamping the lumen for use with the peristaltic mechanism of the medical infusion pump. Another interior surface is provided in the molded conduit which is associated with another of the plurality of elongated sections of the integral elastomer conduit. The second interior surface defines a second interior region having surface characteristics for coupling ultrasound across the conduit traversed to the lumen in order to detect gas entrainment and the like. The second interior region thus provides a textured surface relative to the first interior region to direct the signal energy from the signal coupled across the conduit traversed to the lumen. Additionally, external features may be provided for positioning the plurality of elongated tubular sections of the conduit relative to the peristaltic pumping mechanism of the medical infusion pump for fluid transport and characterization.

Claims

1. A unitary molded elastomer conduit for fluid transport, the conduit comprising:

a plurality of elongated tubular sections defining a continuous lumen therethrough;

a first interior surface of the conduit associated with one of the plurality of elongated tubular sections comprising a first interior region for clamping off said lumen; and

a second interior surface of the conduit associated with another of the plurality of elongated tubular sections comprising a second interior region for coupling an ultrasonic energy signal across the conduit transverse to the lumen to characterize the fluid transport said second interior region having a textured surface relative to said first interior region effecting the propagation of the transmission of the signal energy from the signal coupled across the conduit transverse to the lumen thus enhancing the discrimination of entrained air detection.

2. A conduit as recited in claim 1 wherein said second interior surface is textured relative to said first interior region for impedance-dependent transmission of the signal energy.

3. A conduit as recited in claim 1 comprising a third interior surface of the conduit associated with another of the plurality of elongated tubular sections comprising a third interior region for receiving a peristaltic pumping mechanism for constraining a pumping area of the conduit.

4. A conduit as recited in claim 1 wherein said second interior surface is knurled relative to said first interior surface.

5. A conduit as recited in claim 1 wherein said plurality of elongated tubular sections are injection molded over a core pin to form the unitary molded elastomer conduit.

6. A conduit as recited in claim 1 wherein the elastomer comprises a pyrogen free silicone compound.

7. A conduit as recited in claim 1 comprising an exterior surface relative to said second interior surface of the conduit associated with the elongated tubular section, the exterior surface for coupling the signal across the conduit transverse to the lumen.

8. A conduit as recited in claim 7 wherein said second interior surface and said exterior surface of the conduit are provided for coupling ultrasonic energy transverse to the lumen to characterize the fluid transport.

9. A conduit as recited in claim 8 wherein said exterior surface relative to said second interior surface of the conduit associated with the plurality of elongated tubular sections is smooth relative to the exterior surfaces of others of the associated plurality of elongated tubular sections, the relatively smooth exterior surface being provided for improving the acoustic transmission of the signal across the conduit.

10. A conduit as recited in claim 1 comprising one or more external features for positioning said plurality of elongated tubular sections of the conduit for fluid transport and characterization.

11. A conduit as recited in claim 10 wherein said one or more external features comprise different thicknesses for closing the tubular section to facilitate clamping off of the lumen of the conduit.

12. A method of making a unitary molded elastomer conduit for use with a medical infusion pump, the conduit comprising:

providing a plurality of elongated tubular sections defining a continuous lumen therethrough;

molding a first interior surface of the conduit associated with one of the plurality of elongated tubular sections comprising a first interior region for clamping off said lumen;

molding a second interior surface of the conduit associated with another of the plurality of elongated tubular sections comprising a second interior region for coupling a signal across the conduit transverse to the lumen to characterize the fluid transport, said second interior region having a textured surface relative to said first interior region directing the signal energy from the signal coupled across the conduit transverse to the lumen; and

said first interior region and its associated elongated tubular section being positioned relative to the peristaltic pumping mechanism of the medical infusion pump.

13. A method as recited in claim 12 comprising the step of molding a third interior surface of the conduit associated with another of the plurality of elongated tubular sections for providing a pumping area which receives a peristaltic mechanism on the conduit.

14. A method as recited in claim 12 comprising the step of texturing the surface of the second interior region for providing impedance-dependent transmission of the energy from the signal coupled across the conduit traverse to the lumen for enhancing the discrimination of entrained air detection.

15. A method as recited in claim 12 comprising the step of clamping the lumen by providing an external force at external features on the molded second interior surface.

16. A method as recited in claim 12 wherein said providing step comprises forming a plurality of elongated tubular sections having one or more external features receivable in a cassette which is insertable into the medical infusion pump.

17. A method as recited in claim 16 wherein said external features are molded for positioning the plurality of elongated tubular sections of the conduit at predetermined locations of the cassette relative to the peristaltic pumping mechanism of the medical infusion pump.

18. A method as recited in claim 17 comprising the steps of providing external features for self positioning of the conduit.

19. A method as recited in claim 18 wherein the providing of the external features prevents moving of the conduit during pumping cycles.

20. A method as recited in claim 17 wherein said external features are molded with an outer collar or ring on the outside of the conduit for positioning relative to the peristaltic pumping mechanism of the medical infusion pump.

21. A method as recited in claim 20 comprising the step of providing an inner collar to position the interior conduit for registration with coupled tubing.

22. A method as recited in claim 20 wherein said external features provide for registration of at least said first interior region and the associated elongated tubular section relative to the peristaltic pumping mechanism of the medical infusion pump.

23. A method as recited in claim 20 wherein said external features prevent the conduit from twisting inside said cassette to maintain a uniform storage modulus for the conduit inside said cassette.

24. A method of infusing a medicament with a medical infusion pump, the method comprising the steps of:

molding a unitary elastomer conduit having a plurality of tubular sections defining a continuous lumen therethrough;

securing the conduit in a cassette for being received by the medical infusion pump;

providing a first interior surface of the conduit associated with one of the plurality of elongated tubular sections with a first interior region for clamping off the lumen;

providing a second interior surface of the conduit associated with another of the plurality of elongated tubular sections with a second interior region for coupling a signal across the conduit traversed to the lumen to characterize fluid transport;

texturing the surface relative to the first interior region to facilitate the transmission of the signal coupled across the conduit traversed to the lumen; and

receiving a liquid medicament at the conduit, the first interior region and the associated tubular section being positioned relative to the peristaltic pumping mechanism of the medical infusion pump for fluid transport through the continuous lumen defined by the plurality of elongated tubular sections of the conduit.

25. A method as recited in claim 24 comprising the step of providing molded features on the outside of the conduit for locating the plurality of elongated tubular sections of the conduit within the cassette.

26. A method as recited in claim 24 providing a smooth external surface relative to the second interior region having the textured interior surface to direct the signal energy from the signal coupled across the conduit traversed to the lumen.

27. A method as recited in claim 26 comprising the step of providing an ultrasonic signal at the second interior region for coupling across the conduit traversed to the lumen to characterize the fluid transport.

28. A method as recited in claim 27 comprising the step of providing a coarse interior surface of the conduit to prevent sticking of the surface while facilitating pumping therethrough.

29. A medical infusion pump comprising:

a pump chamber cassette conduit comprising

a plurality of elongated tubular sections defining a continuous lumen therethrough;

a first interior surface of the conduit associated with one of the plurality of elongated tubular sections comprising a first interior region for clamping off said lumen; and

a second interior surface of the conduit associated with another of the plurality of elongated tubular sections comprising a second interior region for coupling a signal across the conduit transverse to the lumen to characterize the fluid transport, said second interior region having a textured surface relative to said first interior region directing the signal energy from the signal coupled across the conduit transverse to the lumen;

a tube for receiving a liquid medicament at the conduit, the first interior region and the associated tubular section being positioned relative to the peristaltic pumping mechanism of the medical infusion pump for fluid transport through the continuous lumen defined by the plurality of elongated tubular sections of the conduit; and

a peristaltic pump mechanism for transporting the liquid medicament across the conduit of the pump chamber cassette.

30. A medical infusion pump as recited in claim 29 wherein said conduit comprises one or more external features for positioning the plurality of elongated tubular sections of the conduit in the pump chamber cassette for fluid transport by the pump.