Implantable, calibrateable measuring instrument for a body substance and a calibrating method
First Claim
1. An implantable measuring instrument for a body substance, comprising:
- an implantable housing having a first recess therein covered by a semi-permeable membrane which admits a selected body substance therethrough;
a channel in fluid communication with the volume between said recess and said membrane;
measuring means communicating with said channel for measuring said selected body substance;
a conveying means for circulating fluid containing said body substance along said measuring means and having an output connected to an output path;
an expandable storage means in fluid communication with said volume between said membrane and said recess;
a second recess in said housing in fluid communication with said measuring means; and
a pierceable, resealable septum covering said second recess adapted for the introduction and withdrawal of a cannula therethrough.
1 Assignment
0 Petitions
Accused Products
Abstract
An implantable measuring instrument for a body substance for use in controlling an implantable infusion device has a housing with a recess covered by a semi-permeable membrane which permits transfer of molecules of a selected size therethrough. The volume defined by the recess and the membrane is in communication with an expandable chamber in the housing and a channel leading directly or indirectly via an additional membrane to a sensor for the body substances to interest. The channel is also in communication with a pump. There is also provided another recess covered by a pierceable, resealable septum. A conduit leads from the septum to the sensor. For calibrating the instrument, a cannula is introduced through the septum, and all of the fluid in the conduit leading to the sensor is withdrawn by suction. A known calibrating substance is then introduced by the cannula through the septum until the conduit leading to the sensor is filled. Data can then be acquired from the sensor, and if necessary one or more operating parameters of the instrument can be re-set. This procedure can also be used for rinsing and/or reactivating the sensor.
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Citations
18 Claims
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1. An implantable measuring instrument for a body substance, comprising:
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an implantable housing having a first recess therein covered by a semi-permeable membrane which admits a selected body substance therethrough; a channel in fluid communication with the volume between said recess and said membrane; measuring means communicating with said channel for measuring said selected body substance; a conveying means for circulating fluid containing said body substance along said measuring means and having an output connected to an output path; an expandable storage means in fluid communication with said volume between said membrane and said recess; a second recess in said housing in fluid communication with said measuring means; and a pierceable, resealable septum covering said second recess adapted for the introduction and withdrawal of a cannula therethrough. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An implantable measuring instrument for a body substance, comprising:
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a housing having a first recess therein; a semi-permeable membrane covering said recess and defining a volume between said membrane and said recess, said membrane having a permeation characteristic for transmitting molecule of a size corresponding to said body substance; an expandable storage means in said housing in fluid communication with said volume; a channel in said housing in fluid communication with said volume; a sensor for measuring said body substance disposed in said channel; a pump having an input in fluid communication with said channel and having an output; a discharge channel connected to said output of said pump and leading to an exterior of said housing; a second recess in said housing in fluid communication with said channel; and a pierceable, resealable septum covering said second recess adapted for permitting the introduction and withdrawal of a cannula therethrough, said cannula, when introduced through said septum, being in fluid communication with said channel, said sensor, said volume and said storage chamber.
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10. An implantable measuring instrument for a body substance, comprising:
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a housing having a first recess therein; a semi-permeable membrane covering said first recess and defining a volume between said membrane and said recess, said membrane having a permeation characteristic selected for maintaining an equilibrum concentration of said body substance on both sides thereof; an expandable storage means in fluid communication with said volume; a channel in said housing in fluid communication with said volume; a sensor for measuring said body substance disposed in said channel; a pump having an input in fluid communication with said channel and having an output in fluid communication with said storage means, whereby an output path for fluid from said pump is formed leading through said storage means, through said volume, and through said channel; a second recess in said housing in fluid communication with said channel; and a pierceable, resealable septum covering said second recess adapted for permitting the introduction and withdrawal of a cannula therethrough, said cannula, when introduced through said septum, being in fluid communication with said channel, said measuring sensor, said volume, and said storage chamber.
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11. An implantable measuring instrument for a body substance, comprising:
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a housing having a first recess therein; a semi-permeable membrane covering said recess and defining a volume between said membrane and said recess, said membrane having a permeation characteristic selected for transmitting molecules of a size corresponding to said body substance; an expandable storage means in said housing in fluid communication with said volume; a channel in said housing in fluid communication with said volume; an additional semipermeable membrane dividing a first chamber from a second chamber, said first chamber communicating with said channel; a sensor for measuring said body substance disposed in said second chamber; a pump having an input in fluid communication with said channel and having an output; a discharge channel connected to said output of said pump and leading to an exterior of said housing; a second recess in said housing in fluid communication with said second chamber; and a piercable, resealable septum covering said second recess adapted for permitting the introduction and withdrawal of a cannula therethrough, said cannula, when introduced through said septum, being in fluid communication with said second chamber and said sensor. - View Dependent Claims (12, 13, 14)
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15. An implantable measuring instrument for a body substance, comprising:
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a housing having a first recess therein; a semi-permeable membrane covering said first recess and defining a volume between said membrane and said recess, said membrane having a permeation characteristic selected for maintaining an equilibrum concentration of said body substance on both sides thereof; an expandable storage means in fluid communication with said volume; a channel in said housing in fluid communication with said volume; an additional semipermeable membrane dividing a first chamber from a second chamber, said first chamber communicating with said channel; a sensor for measuring said body substance disposed in said second chamber; a pump having an input in fluid communication with said channel and having an output in fluid communication with said storage means, whereby an output path for fluid from said pump is formed leading through said storage means, through said volume, and through said channel; a second recess in said housing in fluid communication with said second chamber; and a pierceable, resealable septum covering said second recess adapted for permitting the introduction and withdrawal of a cannula therethrough, said cannula, when introduced through said septaum, being in fluid communication with said second chamber and said measuring sensor. - View Dependent Claims (16, 17, 18)
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Specification