Innovative pumping system for peristaltic pumps
First Claim
1. The combination of an extruded thin wall tubing and a peristaltic pump having at least two rollers, said tubing having an unreinforced outer wall which is directly engaged by said rollers and a low spallative wall resistant to fatigue spalling, said tubing extruded of an elastomeric thermoplastic material formed with a predetermined set curvature having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having a substantially improved pumping lifetime and the ability to withstand an outlet pressure of at least 300 mmHg.
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Abstract
The invention is a pumping system composed of a relatively thin wall extruded tubing that in different forms can provide flow regulation for peristaltic pumps, reduce spallation, extend pumping life, provide means to measure inlet and outlet pressure of the peristaltic pump and limits the inlet and outlet pressure generated by peristaltic pumps, and a special peristaltic pump that takes advantage of the characteristics of the aforementioned tubing. The invention has particular usefulness in the medical industry for pumping physiological or nutritional liquids.
226 Citations
25 Claims
- 1. The combination of an extruded thin wall tubing and a peristaltic pump having at least two rollers, said tubing having an unreinforced outer wall which is directly engaged by said rollers and a low spallative wall resistant to fatigue spalling, said tubing extruded of an elastomeric thermoplastic material formed with a predetermined set curvature having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having a substantially improved pumping lifetime and the ability to withstand an outlet pressure of at least 300 mmHg.
- 2. The combination of an extruded thermoplastic tubing and a peristaltic pump, said tubing having an offset inner diameter which forms an eccentric tubing with a thin wall portion, said tubing having a pair of fittings which orient the tubing to be mounted in said pump such that the sum of the thickness of opposite walls is constant when compressed by said peristaltic pump, said tubing having a ratio of inner diameter to thickness of said thin wall portion of at least 9 to 1, an inner wall resistant to fatigue spalling and a substantially improved pumping lifetime.
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3. A method of using the combination of an extruded polyurethane tubing and a peristaltic pump, said method including compressing said tubing with at least two rollers which directly engage a nonreinforced outer wall of said tubing, said tubing formed with a thin wall portion, with a ratio of inner diameter to thickness of said thin wall portion of at least 9 to 1, a wall resistant to fatigue spalling, said method providing a substantially improved pumping lifetime, with said thin wall portion providing substantially improved pump efficiency.
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4. The combination of an extruded polyether-polyurethane tubing and a peristaltic roller pump, said pump having at least two rollers for directly engaging an unreinforced outer wall of said tubing, said tubing having a thin wall portion and a predetermined set curvature with an inner diameter to wall thickness ratio of at least 9 to 1, an inner diameter 0.625 inch or less, and a shore hardness of, at least 60 A, said tubing having a flow sensitivity to inlet pressure equal to K(ID/wall)3 wherein K is a constant that decreases with increased wall durometer, said flow sensitivity providing a decrease in flow of at least 25% for a drop in inlet pressure of 100 mmHg below 0 mmHg, said tubing having an inner wall resistant to fatigue spalling with a substantially improved pumping lifetime.
- 5. The combination of an extruded polyether-polyurethane thin wall tubing for use in pumping blood and a peristaltic pump, said tubing having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having at least first and second inner longitudinal ribs formed therein, to define a non-occlusive blood passageway therebetween which minimizes wall contact and hemolysis when said tubing is collapsed by said peristaltic pump.
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7. A method for manufacturing an thin wall pumping tube for use in a peristaltic pump having a raceway, said method comprising:
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(a) extruding a tube from a polymeric elastomer with a thin wall portion having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having a low spallative wall resistant to fatigue spalling and the ability to withstand an outlet pressure of at least 300 mmHg; (b) setting a predetermined curvature on said tubing after said extrusion step while said tubing is cooled; (c) setting said curvature to assure that when said tubing is placed in a peristaltic pump, said thin wall portion will be compressed to form a line parallel to said pump raceway and perpendicular to an axis of occlusion; (d) whereby said improved thin wall tubing has a substantially increased pump lifetime.
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8. A low power, high efficiency peristaltic pump, said pump comprising:
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(a) a thin wall extruded tubing with the thin wall having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having an inlet and an outlet and formed with a predetermined set curvature; (b) a first means to directly engage said thin wall tubing for non-invasively measuring the pressure of a fluid within said thin wall tubing at said inlet and said outlet, and generating pressure signals in response thereto; (c) a second means for directly engaging the outer wall of said tubing and sequentially occluding said thin wall tubing to pump a fluid therethrough. (d) the combination providing a high pumping efficiency wherein at 250 mmHg outlet pressure, no more than 35% of the power consumed by the pump is used in compressing said thin wall tubing.
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9. A low power high efficiency pump for extra-corporeal circulation, said pump comprising:
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(a) a thin wall extruded tubing with the thin wall having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having an inlet and an outlet and formed with a predetermined set curvature; (b) at least a pair of rotating and resiliently biased rollers for directly engaging the outer wall of said tubing and sequentially and at least partially occluding the thin wall tubing to pump blood therethrough; (c) a direct drive motor for rotating said rollers to at least partially occlude said thin wall tubing; (d) the combination providing a high pumping efficiency wherein at 250 mmHg outlet pressure, no more than 35% of the power consumed by the pump is used in compressing said thin wall tubing.
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10. A method for using an extruded polyether-polyurethane tubing in a peristaltic pump, said method including compressing said tubing with a plurality of tube engaging elements which directly engage a non-reinforced outer wall of said tubing, said tubing formed with a thin wall portion, with a ratio of inner diameter to thickness of said thin wall portion of at least 9 to 1, an inner wall resistant to fatigue spalling, said method providing a substantially improved pumping lifetime with said thin wall portion providing substantially improved pump efficiency.
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11. An extruded polyurethane tubing for use in pumping blood in a peristaltic roller pump, said pump having at least two rollers for directly engaging an unreinforced outer wall of said tubing, said tubing having a thin wall portion with an inner diameter to wall thickness ratio of at least 9 to 1 and formed with a predetermined set curvature, an inner diameter of 0.625 inch or less, and a shore hardness of at least 60 A, said tubing having a flow sensitivity to inlet pressure equal to K(ID/wall)3 wherein K is a constant that decreases with increased wall durometer, said flow sensitivity providing a decrease in flow of at least 25% for a drop in inlet pressure of 100 mmHg, below 0 mmHg, said tubing having an inner wall resistant to fatigue spalling with a substantially improved pumping lifetime.
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12. An extruded thermoplastic thin wall tubing for using in pumping blood in peristaltic pumps, said tubing having an inner diameter to thin wall thickness ratio of at least 9 to 1 and formed with a predetermined set curvature, said tubing having at least first and second inner longitudinal ribs formed therein, to define a non-occlusive blood passageway therebetween which minimizes wall contact and hemolysis when said tubing is collapsed by said peristaltic pump.
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13. A combination of an extruded tubing having a thin wall and an extracorporeal circuit for surgery or dialysis, wherein said improved extruded tubing is particularly adapted for use in a peristaltic pump, said tubing having an unreinforced outer wall which is directly engaged by said peristaltic pump, and a low spallative wall resistant to fatigue spalling, said tubing extruded from a polymeric thermoplastic elastomer to form a tube having an inner diameter to thin wall thickness ratio of at least 9 to 1 and formed with a predetermined set curvature, said tube having a substantially improved pumping lifetime and the ability to withstand and outlet pressure of at least 300 mmHg.
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14. The combination of an extruded tubing having a thin wall and a peristaltic pump having a plurality of tube engaging elements, said tubing having an unreinforced outer wall which is directly engaged by said tube engaging elements and a low spallative wall resistant to fatigue spalling, said tubing extruded of a polymeric thermoplastic elastomer having an inner diameter to thin wall thickness ratio of at least 9 to 1 and formed with a predetermined set curvature, said tubing having a substantially improved pumping lifetime and the ability to withstand and outlet pressure of at least 300 mmHg.
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23. A low power, high efficiency peristaltic I.V. pump for physiological fluid, said pump comprising:
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(a) a thin wall extruded thermoplastic tubing with the thin wall having an inner diameter of less than 0.25 inches and an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having inlet and an outlet; (b) a first means to directly engage said thin wall tubing for non-invasively measuring the pressure of a physiological fluid within said thin wall tubing at said inlet and said outlet, and generating pressure signals in response thereto; (c) a second means for directly engaging the outer wall of said tubing and sequentially occluding said thin wall tubing to pump a fluid therethrough; (d) the combination providing a high pumping efficiency wherein at 250 mmHg outlet pressure, no more than 35% of the power consumed by the pump is used in compressing said thin wall tubing.
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24. A low power, high efficiency peristaltic I.V. pump for physiological fluids, said pump comprising:
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(a) a thin wall extruded thermoplastic tubing having an offset inner diameter which forms an eccentric tubing with a thin wall having an inner diameter to thin wall thickness ratio of at least 9 to 1, said tubing having an inlet and an outlet, said tubing having means to orient the tubing in said pump such that the sum of the thickness of opposite walls is constant when compressed by said peristaltic pump; (b) a first means to directly engage said thin wall tubing for non-invasively measuring the pressure of a physiological fluid within said thin wall tubing at said inlet and said outlet, and generating pressure signals in response thereto; (c) a second means for directly engaging the outer wall of said tubing and sequentially occluding said thin wall tubing to pump a fluid therethrough; (d) the combination providing a high pumping efficiency wherein at 250 mmHg pressure, no more than 35% of the power consumed by the pump is used in compressing said thin wall tubing.
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25. The combination of an extruded polyurethane tubing and a peristaltic roller pump, said pump having at least two rollers for directly engaging an unreinforced outer wall of said tubing, said tubing having an offset inner diameter which forms an eccentric tubing and a thin portion with an inner diameter to wall thickness ratio of at least 9 to 1, said tubing including means to orient the tubing in said pump such that the sum of the thickness of opposite walls is constant when compressed by said peristaltic pump, said tubing having an inner diameter of 0.625 inches or less, and a shore hardness of at least 60 A, said tubing having a flow sensitivity to inlet pressure equal to K (ID/wall )3 wherein K is a constant that decreases with increased wall durometer, said flow sensitivity providing a decrease in flow of at least 25% for a drop in inlet pressure of 100 mmHg to below 0 mmHg, said tubing having an inner wall resistant to fatigue spalling with a substantially improved pumping lifetime.
Specification