US5564434A — Implantable capacitive absolute pressure and temp…

Claim 1

Independent Claim 255 words

An implantable lead having a capacitive pressure sensor module for providing signals representative of the magnitude of body fluid pressure at a selected site and ambient operating conditions, including body temperature, at the site, said lead comprising: an elongated implantable lead body having proximal and distal end sections and having first and second electrical conductors extending from the proximal end section to the distal end section, said proximal end adapted to be coupled to a biasing signal source, and said distal end section adapted to be implanted in a body position for measuring a varying body fluid pressure; and a pressure sensor module formed in the distal end section of the lead body and coupled to said first and second electrical conductors, the pressure sensor module of said lead comprising: a module housing attached to said lead body adapted to be positioned in a body cavity and enclosing a hermetically sealed chamber; pressure deformable pickoff capacitor means for varying in capacitance in response to variations in fluid pressure having a first plate formed of a pressure deformable diaphragm of said module housing and a second plate spaced apart therefrom; reference capacitor means having a first plate formed of a relatively non-deformable portion of said diaphragm of said module housing and a second plate spaced apart therefrom; a substrate supported within said module housing for supporting said second plates; and pressure and temperature signal modulating circuit means supported on said substrate within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors.

Claim 2

Dependent Claim 255 words

An implantable lead having a capacitive pressure sensor module for providing signals representative of the magnitude of body fluid pressure at a selected site and ambient operating conditions, including body temperature, at the site, said lead comprising: an elongated implantable lead body having proximal and distal end sections and having first and second electrical conductors extending from the proximal end section to the distal end section, said proximal end adapted to be coupled to a biasing signal source, and said distal end section adapted to be implanted in a body position for measuring a varying body fluid pressure; and a pressure sensor module formed in the distal end section of the lead body and coupled to said first and second electrical conductors, the pressure sensor module of said lead comprising: a module housing attached to said lead body adapted to be positioned in a body cavity and enclosing a hermetically sealed chamber; pressure deformable pickoff capacitor means for varying in capacitance in response to variations in fluid pressure having a first plate formed of a pressure deformable diaphragm of said module housing and a second plate spaced apart therefrom; reference capacitor means having a first plate formed of a relatively non-deformable portion of said diaphragm of said module housing and a second plate spaced apart therefrom; a substrate supported within said module housing for supporting said second plates; and pressure and temperature signal modulating circuit means supported on said substrate within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors.

Claim 3

Dependent Claim 146 words

The implantable lead of claim 1 wherein: said first plate of said pickoff capacitor means is formed of a pressure deformable, substantially planar diaphragm having a first predetermined surface area formed by a plane of said module housing having an exterior substantially planar surface and a parallel interior substantially planar surface within said hermetically sealed chamber at least said interior planar surface comprising conductive material, said planar diaphragm adapted to be deformed in said first predetermined surface area by variations in fluid pressure outside the module housing; and said first plate of said reference capacitor means is formed of a second predetermined substantially planar surface area of said interior surface spaced apart from and co-planar with said first predetermined surface area and located so as to be on a relatively non-deformable area of said substantially planar diaphragm by variations in fluid pressure outside the module housing.

Claim 4

Dependent Claim 69 words

The implantable lead of claim 2 further comprising: disposition of said second plates of said pickoff and reference capacitor means on a first surface of said substrate opposite said first plate's locations on said diaphragm so as to form capacitors thereby; and means for spacing said second plates of said pickoff and reference capacitor means a fixed distance from said first plates of said pickoff and reference capacitor means.

Claim 5

Dependent Claim 129 words

The implantable lead of claim 3 wherein: said second plates of said pickoff and reference capacitor means further comprise pickoff and reference capacitor platings of a first thickness formed on said first surface of said substrate conforming to said pickoff and reference capacitor plate patterns, respectively; and said spacing means further comprises: a plurality of standoffs of a second thickness greater than said first thickness formed on said first surface of said substrate; and means for urging said standoffs against said interior surface for spacing said second plates of said pickoff and reference capacitor means from said first plates of said pickoff and reference capacitor means by a predetermined gap establishing the same capacitance for both the pickoff and reference capacitors in the absence of deformation of said diaphragm.

Claim 6

Dependent Claim 39 words

The implantable lead of claim 3 wherein said standoffs are formed of standoff platings of said second thickness formed on said first surface of said substrate in areas outside said pickoff and reference capacitor platings and electrically isolated therefrom.

Claim 7

Dependent Claim 47 words

The implantable lead of claim 4 wherein said pressure and temperature signal modulating circuit means is supported on a second surface of said substrate within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors and to said pickoff and reference capacitor platings.

Claim 8

Dependent Claim 79 words

The implantable lead of claim 1 further comprising: means for supporting said second plates of said pickoff and reference capacitor means on a first surface of said substrate; and means for spacing said second plates of said pickoff and reference capacitor means a fixed distance from said first plates of said pickoff and reference capacitor means whereby a predetermined gap establishes the same capacitance for both the pickoff and reference capacitors in the absence of deformation of said diaphragm.

Claim 9

Dependent Claim 44 words

The implantable lead of claim 7 wherein said pressure and temperature signal modulating circuit means is supported on a second surface of said substrate within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors and to said second plates.

Claim 10

Dependent Claim 93 words

The implantable lead of claim 1 wherein: said module housing is formed of a conductive material having an exterior planar surface and an interior planar surface shaped to form said planar diaphragm having a fixed thickness and perimeter boundary in a planar section thereof to form said first deformable plate of said pickoff capacitor in a pickoff capacitor plate pattern, said interior planar surface extending beyond the boundary of said planar diaphragm to form said first plate of said reference capacitor in a reference capacitor plate pattern adjacent to said first deformable plate.

Claim 11

Dependent Claim 122 words

The implantable lead of claim 9 further comprising: disposition of said second plate of said pickoff capacitor means on a first surface of said substrate, said second plate of said pickoff capacitor means shaped to correspond to said pickoff capacitor plate pattern opposite said first pick off plate's location on said diaphragm; disposition of said second plate of said reference capacitor means on a first surface of said substrate, said second plate of said reference capacitor shaped to correspond to said reference capacitor plate pattern opposite said first reference plate's location on said diaphragm; and means for spacing said second plates of said pickoff and reference capacitor means a fixed distance from said first plates of said pickoff and reference capacitor means.

Claim 12

Dependent Claim 121 words

The implantable lead of claim 10 wherein: said second plates of said pickoff and reference capacitor means further comprise pickoff and reference capacitor platings of a first thickness formed on said first surface of said substrate conforming to said pickoff and reference capacitor plate patterns, respectively; and said spacing means further comprises: a plurality of standoffs of a second thickness greater than said first thickness formed on said first surface of said substrate; and means for urging said standoffs against said interior surface for spacing said second plates of said pickoff and reference capacitor means from said first plates of said pickoff and reference capacitor means by a predetermined gap establishing the same capacitance for both the pickoff and reference capacitors.

Claim 13

Dependent Claim 39 words

The implantable lead of claim 11 wherein said standoffs are formed of standoff platings of said second thickness formed on said first surface of said substrate in areas outside said pickoff and reference capacitor platings and electrically isolated therefrom.

Claim 14

Dependent Claim 47 words

The implantable lead of claim 10 wherein said pressure and temperature signal modulating circuit means is supported on a second surface of said substrate within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors and to said pickoff and reference capacitor platings.

Claim 15

Dependent Claim 35 words

The implantable lead of claim 1 wherein said module housing is fabricated of a conductive metal and further comprising: insulative body compatible sheath means for electrically isolating said module housing from body fluids and tissue.

Claim 16

Dependent Claim 26 words

The implantable lead of claim 14 wherein said sheath means further comprises an insulative, uniform thickness coating of an adhering body compatible material overlying said diaphragm.

Claim 17

Dependent Claim 37 words

The implantable lead of claim 14 wherein said sheath means further comprises a tubular sheath fitting over said module housing and coupled to said insulative, uniform thickness coating of an adhering body compatible material overlying said diaphragm.

Claim 18

Dependent Claim 98 words

The implantable lead of claim 1 wherein said pressure and temperature signal modulating circuit means further comprises: means for receiving an externally applied biasing signal on said first and second conductors and for generating charging and discharging currents therefrom which vary in magnitude with ambient temperature; means for alternately charging and discharging said pickoff and reference capacitor means with said charging and discharging currents; and timing pulse generating means for generating pickoff and reference timing pulses on one of said electrical conductors, the timing pulses separating the alternate charging time intervals of the pickoff and reference capacitor means.

Claim 19

Dependent Claim 100 words

The implantable lead of claim 17 wherein said timing pulse generating means further comprises: means for establishing a charge threshold voltage; means for detecting the charging of said reference capacitor means to said charge threshold voltage and for generating a pickoff timing pulse on said first electrical conductor in response thereto, said pickoff timing pulse having a first predetermined characteristic; means for detecting the charging of said pickoff capacitor means to said charge threshold voltage and for generating a reference timing pulse in response thereto, said reference timing pulse having a second predetermined characteristic distinguishable from said first predetermined characteristic.

Claim 20

Dependent Claim 225 words

An implantable capacitive implantable lead for providing signals representative of the magnitude of body fluid pressure at a selected site and ambient operating conditions, including body temperature, at the site comprising: an elongated implantable lead body having proximal and distal end sections and having first and second electrical conductors extending from the proximal end section to the distal end section, said proximal end adapted to be coupled to a biasing signal source, and said distal end section adapted to be implanted in a body position for measuring a varying body fluid pressure; and a implantable module formed in the distal end section of the lead body and coupled to said first and second electrical conductors, the implantable module further comprising: a module housing attached to said lead body adapted to be positioned in a body cavity and enclosing a hermetically sealed chamber; pressure deformable pickoff capacitor means for varying in capacitance in response to variations in fluid pressure having a first plate formed of a pressure deformable diaphragm of said module housing and a second plate spaced apart therefrom; reference capacitor means having a first plate formed of a non-deformable portion of said module housing and a second plate spaced apart therefrom; and pressure and temperature signal modulating circuit means within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors.

Claim 21

Dependent Claim 225 words

An implantable capacitive implantable lead for providing signals representative of the magnitude of body fluid pressure at a selected site and ambient operating conditions, including body temperature, at the site comprising: an elongated implantable lead body having proximal and distal end sections and having first and second electrical conductors extending from the proximal end section to the distal end section, said proximal end adapted to be coupled to a biasing signal source, and said distal end section adapted to be implanted in a body position for measuring a varying body fluid pressure; and a implantable module formed in the distal end section of the lead body and coupled to said first and second electrical conductors, the implantable module further comprising: a module housing attached to said lead body adapted to be positioned in a body cavity and enclosing a hermetically sealed chamber; pressure deformable pickoff capacitor means for varying in capacitance in response to variations in fluid pressure having a first plate formed of a pressure deformable diaphragm of said module housing and a second plate spaced apart therefrom; reference capacitor means having a first plate formed of a non-deformable portion of said module housing and a second plate spaced apart therefrom; and pressure and temperature signal modulating circuit means within said hermetically sealed chamber and electrically coupled to said first and second electrical conductors.

Claim 22

Dependent Claim 101 words

The implantable capacitive pressure sensor lead of claim 19 wherein said pressure and temperature signal modulating circuit means further comprises: means for receiving an externally applied biasing signal on said first and second conductors and for generating charging and discharging currents therefrom which vary in magnitude with ambient temperature; means for alternately charging and discharging said pickoff and reference capacitor means with said charging and discharging currents; and timing pulse generating means for generating pickoff and reference timing pulses on one of said electrical conductors, the timing pulses separating the alternate charging time intervals of the pickoff and reference capacitor means.

Claim 23

Dependent Claim 103 words

The implantable capacitive pressure sensor lead of claim 20 wherein said timing pulse generating means further comprises: means for establishing a charge threshold voltage; means for detecting the charging of said reference capacitor means to said charge threshold voltage and for generating a pickoff timing pulse on said first electrical conductor in response thereto, said pickoff timing pulse having a first predetermined characteristic; means for detecting the charging of said pickoff capacitor means to said charge threshold voltage and for generating a reference timing pulse in response thereto, said reference timing pulse having a second predetermined characteristic distinguishable from said first predetermined characteristic.

Claim 24

Dependent Claim 68 words

The pressure and temperature sensing lead of claim 21 wherein: said first predetermined characteristic comprises a first pulse width, pulse amplitude and pulse leading edge slope; and said second predetermined characteristic comprises a stepped pulse having leading and trailing steps, said leading step corresponding to said first pulse width, pulse amplitude an pulse leading edge slope, and said trailing step having a second pulse amplitude and pulse width.

Claim 25

Dependent Claim 253 words

A pressure sensor module having a housing enclosing a hermetically sealed chamber for implantation into a living body, said housing for attachment to an implantable device such that the housing is adapted to be positioned in a body so as to sense pressure therein and; pressure deformable pickoff capacitor means for varying in capacitance in response to variations in pressure exterior to said chamber having a first pressure deformable, substantially flat, diaphragm element with an interior surface and an exterior surface, said diaphragm element disposed on said housing so as to have said exterior surface thereof exposed to said body and the interior surface thereof facing interior to said chamber, said interior surface disposed to substantially parallel alignment with a second plate member spaced apart from the interior surface of said diaphragm and within said chamber, and having a conductive pickoff capacitor member lining or formed of a portion of said interior surface of said diaphragm element and having a second capacitor conductive member lining or formed of a portion of said second plate member spaced from said first conductive member; reference capacitor pressure sensing means having a first conductive capacitor member lining a relatively non-deformable portion of said diaphragm element of said interior surface and being electrically isolated from and non coincident with said pickoff capacitor first conductive member, and a second conductive capacitor member on said second plate spaced apart from said reference capacitor conductive member; pressure and temperature signal modulating circuit electrically coupled to said first and second electrical conductors.

Claim 26

Dependent Claim 253 words

A pressure sensor module having a housing enclosing a hermetically sealed chamber for implantation into a living body, said housing for attachment to an implantable device such that the housing is adapted to be positioned in a body so as to sense pressure therein and; pressure deformable pickoff capacitor means for varying in capacitance in response to variations in pressure exterior to said chamber having a first pressure deformable, substantially flat, diaphragm element with an interior surface and an exterior surface, said diaphragm element disposed on said housing so as to have said exterior surface thereof exposed to said body and the interior surface thereof facing interior to said chamber, said interior surface disposed to substantially parallel alignment with a second plate member spaced apart from the interior surface of said diaphragm and within said chamber, and having a conductive pickoff capacitor member lining or formed of a portion of said interior surface of said diaphragm element and having a second capacitor conductive member lining or formed of a portion of said second plate member spaced from said first conductive member; reference capacitor pressure sensing means having a first conductive capacitor member lining a relatively non-deformable portion of said diaphragm element of said interior surface and being electrically isolated from and non coincident with said pickoff capacitor first conductive member, and a second conductive capacitor member on said second plate spaced apart from said reference capacitor conductive member; pressure and temperature signal modulating circuit electrically coupled to said first and second electrical conductors.

Claim 27

Dependent Claim 26 words

A pressure sensor module as set forth in claim 23 wherein said second conductive capacitor member of said capacitive and said pickoff capacitors are electrically coextensive.

Claim 28

Dependent Claim 99 words

The pressure sensor module of claim 23 wherein said pressure and temperature signal modulating circuit means further comprises: means for receiving an externally applied biasing signal on said first and second conductors and for generating charging and discharging currents therefrom which vary in magnitude with ambient temperature; means for alternately charging and discharging said pickoff and reference capacitor means with said charging and discharging currents; and timing pulse generating means for generating pickoff and reference timing pulses on one of said electrical conductors, the timing pulses separating the alternate charging time intervals of the pickoff and reference capacitor means.

Claim 29

Dependent Claim 101 words

The pressure sensor module of claim 25 wherein said timing pulse generating means further comprises: means for establishing a charge threshold voltage; means for detecting the charging of said reference capacitor means to said charge threshold voltage and for generating a pickoff timing pulse on said first electrical conductor in response thereto, said pickoff timing pulse having a first predetermined characteristic; means for detecting the charging of said pickoff capacitor means to said charge threshold voltage and for generating a reference timing pulse in response thereto, said reference timing pulse having a second predetermined characteristic distinguishable from said first predetermined characteristic.

Claim 30

Dependent Claim 68 words

The pressure and temperature sensing module of claim 26 wherein: said first predetermined characteristic comprises a first pulse width, pulse amplitude and pulse leading edge slope; and said second predetermined characteristic comprises a stepped pulse having leading and trailing steps, said leading step corresponding to said first pulse width, pulse amplitude an pulse leading edge slope, and said trailing step having a second pulse amplitude and pulse width.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-10-15	2000-04-15	2000-10-15	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-10-15	2004-04-15	2004-10-15	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-10-15	2008-04-15	2008-10-15	$7700.00	Window Closed / Lapsed

Implantable capacitive absolute pressure and temperature sensor

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag