Liquid-vapor pressure reservoir for medication infusion pump
First Claim
1. A pressure reservoir for use in an implantable medication infusion pump of the type having a hermetically sealed housing with a medication chamber for receiving a supply of a selected liquid medication disposed therein, the medication infusion pump also having pump means disposed within said housing for delivering the medication from the medication chamber to a patient, said pressure reservoir comprising:
- a structural enclosure having a selected liquid-vapor pressure fluid therein, said structural enclosure being mounted within the housing and defining at least one flexible movable wall exposed to the medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said structural enclosure in response to the quantity of the medication within the medication chamber to maintain the medication under a predetermined and substantially constant pressure, wherein said pressure fluid is selected to maintain the medication chamber under a pressure less than atmospheric pressure.
8 Assignments
0 Petitions
Accused Products
Abstract
An improved and simplified pressure reservoir is provided for use with an implantable medication infusion pump to maintain a selected medication in liquid form with a pump housing under a substantially constant pressure. The pressure reservoir comprises a hollow structural enclousre having at least one flexible resilient wall and is adapted to be filled with a selected quantity of a pressure fluid, such as a selected fluorocarbon in a liquid-vapor state, prior to mounting of the reservoir as a structural unit into the infusion pump housing. Within the pump housing, the flexible reservoir wall defines one side of a medication chamber, with the pressure fluid undergoing appropriate change of state to expand or contact the reservoir in a manner maintaining the medication under a substantially constant pressure. The improved reservoir can be provided in a variety of structural shapes and/or utilized in pump housings of various size and shape to permit the pump size to be reduced, or, in the alternative, to increase pump medication capacity without increasing pump housing size.
175 Citations
24 Claims
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1. A pressure reservoir for use in an implantable medication infusion pump of the type having a hermetically sealed housing with a medication chamber for receiving a supply of a selected liquid medication disposed therein, the medication infusion pump also having pump means disposed within said housing for delivering the medication from the medication chamber to a patient, said pressure reservoir comprising:
a structural enclosure having a selected liquid-vapor pressure fluid therein, said structural enclosure being mounted within the housing and defining at least one flexible movable wall exposed to the medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said structural enclosure in response to the quantity of the medication within the medication chamber to maintain the medication under a predetermined and substantially constant pressure, wherein said pressure fluid is selected to maintain the medication chamber under a pressure less than atmospheric pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A pressure reservoir for use in an implantable medication infusion pump of the type having a hermetically sealed housing with a medication chamber for receiving a supply of a selected liquid medication disposed therein, the medication infusion pump also having pump means disposed within said housing for delivering the medication from the medication chamber to a patient, said pressure reservoir comprising:
means defining an expansible structural enclosure having a liquid-vapor pressure fluid therein, said structural enclosure defining at least one flexible movable wall exposed to the medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said structural enclosure in response to the quantity of the medication within the medication chamber to maintain the medication under a predetermined and substantially constant pressure, wherein said pressure fluid is selected to maintain the medication chamber under a pressure less than atmospheric pressure. - View Dependent Claims (10, 11)
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12. A pressure reservoir for use in an implantable medication infusion pump of the type having a hermetically sealed housing with a medication chamber for receiving a supply of a selected liquid medication disposed therein, the medication infusion pump also having pump means disposed within said housing for delivering the medication from the medication chamber to a patient, said pressure reservoir comprising:
a structural enclosure having a selected liquid-vapor pressure fluid therein, said structural enclosure being mounted within the medication chamber and defining at least one flexible movable wall exposed to the medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said structural enclosure in response to the quantity of the medication within the medication chamber to maintain the medication under a predetermined and substantially constant pressure, wherein said pressure fluid is selected to maintain the medication chamber under a pressure less than atmospheric pressure. - View Dependent Claims (13, 14)
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15. A pressure reservoir for use in an implantable medication infusion pump of the type having a hermetically sealed housing with a medication chamber for receiving a supply of a selected liquid medication disposed therein, the medication infusion pump also having pump means disposed within said housing for delivering the medication from the medication chamber to a patient, said pressure reservoir comprising:
a pillow-shaped member having two sides made of a flexible material sealed about the periphery thereof to enclose a selected liquid-vapor pressure fluid therein, said pillow-shaped member being located within the medication chamber and defining a volumetric size within the medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said pillow-shaped member in response to the quantity of the medication within the medication chamber to maintain the medication under a predetermined and substantially constant pressure, wherein said pressure fluid is selected to maintain the medication chamber under a pressure less than atmospheric pressure.
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16. A medication infusion pump, comprising:
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a pump housing having a medication chamber formed therein for receiving a supply of a selected medication; pump means within said housing for delivering the medication from said medication chamber to a patient; and a pressure reservoir comprising a structural enclosure and having a selected liquid-vapor pressure fluid therein, said pressure reservoir being mounted within said pump housing and defining a movable wall exposed to said medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said pressure reservoir in response to the quantity of the medication within said medication chamber to maintain the medication under a predetermined and substantially constant pressure. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. A method of maintaining a selected pressure in a medication chamber contained in an implantable liquid medication infusion pump, said method comprising:
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filling a structural enclosure having at least one flexible wall with a selected liquid-vapor pressure fluid; and installing said structural enclosure within the medication chamber, said pressure fluid being adapted to undergo sufficient liquid-vapor phase change for varying the volumetric size of said structural enclosure in response to the quantity of the medication within the medication chamber to maintain the medication under a predetermined and substantially constant pressure, wherein said pressure fluid is selected to maintain the medication chamber under a pressure less than atmospheric pressure.
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Specification