Patent US5709225A successfully refreshed from Google Patents.
US5709225A
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Combined magnetic field detector and activity detector employing a capacitive sensor, for a medical implant
Assignee: Pacesetter AB
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Filing: 1995-09-20
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Granted: 1998-01-20
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Expires: 2015-09-20
Abstract
Abstract A medical implant contains a magnetic field detector with a sensor whose capacitance changes in the presence of a magnetic field with a predefined strength, and a capacitance-controlled unit connected to the sensor. The capacitance-controlled unit sends a measurement signal to a detection unit. If a measurement signal parameter affected by capacitance exhibits a specific change over a predefined period of time, a detection signal is generated by the detection unit to indicate the presence of a magnetic field. The sensor's capacitance also changes when the sensor moves, and this is utilized for measuring activity in an activity measurement circuit connected to the capacitance-controlled unit and for generating an activity signal on the basis of the measurement signal.
Inventors
- 👤 Goran Budgifvars
- 👤 Inga Bergstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:33
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/36; A61N1/362; A61N1/365; A61N1/36514; A61N1/36542; G; G01; G01R; G01R33/00; G01R33/02; G01V; G01V3/00; G01V3/08; G01V3/081; Y; Y10; Y10S; Y10S128/00; Y10S128/903
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
212 words
A medical implant comprising: a capacitive accelerometer having a capacitance which changes upon motion of said capacitive accelerometer and at least partially coated with a material sensitive to magnetic fields which causes a change in the capacitance of said sensor in the presence of a magnetic field; means connected to said capacitive sensor for generating a signal including a first component dependent on a change in said capacitance due to motion of said capacitive accelerometer and a second component dependent on a change in capacitance of said capacitive accelerometer in the presence of a magnetic field having a predetermined field strength; means for generating an activity signal dependent on said first component; means for generating a magnetic field detection signal dependent on said second component; means for generating a medical therapy, said medical therapy being adjustable and having a plurality of therapy modes; means connected to said means for generating a medical therapy adapted for delivering said medical therapy to a subject; and control means, supplied with said activity signal and with said magnetic field detection signal, for controlling said means for generating a medical therapy for adjusting said medical therapy dependent on said activity signal and for changing a mode of said medical therapy dependent on said magnetic field detection signal.
Claim 2
Dependent Claim
212 words
A medical implant comprising: a capacitive accelerometer having a capacitance which changes upon motion of said capacitive accelerometer and at least partially coated with a material sensitive to magnetic fields which causes a change in the capacitance of said sensor in the presence of a magnetic field; means connected to said capacitive sensor for generating a signal including a first component dependent on a change in said capacitance due to motion of said capacitive accelerometer and a second component dependent on a change in capacitance of said capacitive accelerometer in the presence of a magnetic field having a predetermined field strength; means for generating an activity signal dependent on said first component; means for generating a magnetic field detection signal dependent on said second component; means for generating a medical therapy, said medical therapy being adjustable and having a plurality of therapy modes; means connected to said means for generating a medical therapy adapted for delivering said medical therapy to a subject; and control means, supplied with said activity signal and with said magnetic field detection signal, for controlling said means for generating a medical therapy for adjusting said medical therapy dependent on said activity signal and for changing a mode of said medical therapy dependent on said magnetic field detection signal.
Claim 3
Dependent Claim
85 words
A medical implant as claimed in claim 1 wherein said means for generating a signal comprises: a capacitance-controlled unit connected to said capacitive accelerator which emits a measurement signal having at least one measurement signal parameter which changes dependent on the change in capacitance of said capacitive accelerometer; and means connected to said capacitance-controlled unit and supplied with said measurement signal for generating said detection signal if said at least one measurement signal parameter changes to a predetermined value for a predetermined period of time.
Claim 4
Dependent Claim
31 words
A medical implant as claimed in claim 2 wherein said capacitance-controlled unit comprises a capacitance-controlled amplifier having a gain, and wherein said at least one measurement signal parameter comprises said gain.
Claim 5
Dependent Claim
33 words
A medical implant as claimed in claim 2 wherein said capacitance-controlled unit comprises a capacitance-controlled oscillator having an output frequency, and wherein said at least one measurement signal parameter comprises said output frequency.
Claim 6
Dependent Claim
42 words
A medical implant as claimed in claim 1 wherein said capacitive accelerometer comprises at least two electrode plates, moveable relative to each other, and said capacitance of said capacitive accelerometer changing dependent upon a distance between said at least two electrode plates.
Claim 7
Dependent Claim
25 words
A medical implant as claimed in claim 5 wherein at least one of said electrode plates is coated with said material sensitive to magnetic fields.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-01-19 | 2001-07-21 | 2002-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-19 | 2005-07-21 | 2006-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-19 | 2009-07-21 | 2010-01-20 | $7700.00 | Window Closed / Lapsed |