Apparatus and method for measuring the amount of fluid contained in an implantable medical device
First Claim
1. An implantable medical device for infusing a fluid into a body, comprising:
- an expandable fluid reservoir comprising a first end, a second end, an inlet for receiving the fluid from an outside source and an outlet for dispensing the fluid into the body, the fluid reservoir being continuously expandable between the first end and the second end from an empty position to a full position, one of the first end being continuously movable with respect to the second end and the second end being movable with respect to the first end as the fluid is either added to or removed from the expandable fluid reservoir;
a first coiled-electrical conductor connected to the first end of the expandable fluid reservoir member;
a second coiled electrical conductor connected to the second end of the expandable fluid reservoir member; and
electronic circuit means for measuring the inductance between the first coiled electrical conductor and the second electrical conductor anywhere between the empty position of the fluid reservoir and the full position of the drug reservoir, the electronic circuit inductance measuring means being operably connected to the first and second coiled electrical conductors, the inductance so measured being proportional to a distance separating the first end from the second end.
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Accused Products
Abstract
An implantable pump apparatus and method of operating the implantable pump for infusing a fluid into a body as described. An expandable fluid reservoir member includes a first end, a second end, an inlet for receiving the fluid from an outside source and an outlet for dispensing the fluid into the body. A first conductor is operably attached to the first end of the expandable fluid reservoir member. A second conductor is operably attached to the second end of the expandable fluid reservoir member. The level of fluid within the expandable fluid reservoir member is determined by measuring an inductance value at the first conductor that is proportional to the distance between the first conductor and the second conductor.
71 Citations
23 Claims
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1. An implantable medical device for infusing a fluid into a body, comprising:
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an expandable fluid reservoir comprising a first end, a second end, an inlet for receiving the fluid from an outside source and an outlet for dispensing the fluid into the body, the fluid reservoir being continuously expandable between the first end and the second end from an empty position to a full position, one of the first end being continuously movable with respect to the second end and the second end being movable with respect to the first end as the fluid is either added to or removed from the expandable fluid reservoir;
a first coiled-electrical conductor connected to the first end of the expandable fluid reservoir member;
a second coiled electrical conductor connected to the second end of the expandable fluid reservoir member; and
electronic circuit means for measuring the inductance between the first coiled electrical conductor and the second electrical conductor anywhere between the empty position of the fluid reservoir and the full position of the drug reservoir, the electronic circuit inductance measuring means being operably connected to the first and second coiled electrical conductors, the inductance so measured being proportional to a distance separating the first end from the second end. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of measuring an amount of a fluid contained in an expandable drug reservoir disposed within an implantable medical device, the implantable medical device comprising the expandable fluid reservoir, the reservoir comprising a first end, a second end, an inlet for receiving the fluid from an outside source and an outlet for dispensing the fluid into the body, the fluid reservoir being- expandable between the first end and the second end from an empty position to a full position, one of the first end being movable with respect to the second end and the second end being moveable with respect to the first end as the fluid is either added to or removed from the expandable fluid reservoir, a first coiled electrical conductor connected to the first end of the expandable fluid reservoir member, a second coiled electrical conductor connected to the second end of the expandable fluid reservoir member, and electronic circuit means for measuring the inductance between the first coiled electrical conductor and the second electrical conductor anywhere between the empty position of the fluid reservoir and the full position of the drug reservoir, the electronic circuit inductance measuring means being operably connected to the first and second coiled electrical conductors, the inductance so measured being proportional to a distance separating the first end from the second end, the method comprising:
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providing the expandable fluid reservoir;
adding the fluid to the expandable fluid reservoir member;
dispensing a portion of the fluid from the expandable fluid reservoir member; and
measuring the inductance between the first coiled conductor and the second coiled conductor using the electronic circuit inductance measuring means to determine the amount of fluid in the expandable fluid reservoir member. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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Specification