Pressure sensors circuits
View Patent ↗Implantable pressure sensors and methods for making and using the same are provided. A feature of embodiments of the subject pressure sensors is that they are low-drift sensors. The subject sensors find use in a variety of applications.
1. A pressure sensor circuit comprising:
a Wheatstone bridge for measuring pressure on the circuit, wherein said Wheatstone bridge produces a first output signal representative of the potential across the Wheatstone bridge and a second output signal representative of said pressure;
an amplifier circuit for amplifying said first and second output signals;
an analog-to-digital converter for measuring the ratio of said amplified first and second output signals;
an interface coupled to at least one output of said analog-to-digital converter; and
a source for providing a reference signal to said Wheatstone bridge and for providing a reference signal to said analog-to-digital converter.
2. The circuit according to claim 1 , wherein said Wheatstone bridge reference signal is a current signal.
3. The circuit according to claim 2 , wherein said Wheatstone bridge reference signal is a voltage signal.
4. The circuit according to claim 1 , wherein said circuit is provided on an implantable structure.
5. The circuit according to claim 4 , wherein said implantable structure is configured for implantation into a head chamber.
6. A pressure sensor circuit comprising:
a first Wheatstone bridge for measuring pressure on said circuit, wherein said first Wheatstone bridge produces an output signal representative of said pressure;
a second Wheatstone bridge for measuring strain on said circuit wherein said second Wheatstone bridge produces an output signal representative of said strain;
an amplifier circuit for amplifying said pressure output signal and said strain output voltage signal;
an analog-to-digital converter for measuring the ratio of said amplified pressure output signal to said amplified strain output signal; and
an interface coupled to the at least one output of the analog-to-digital converter.
7. The circuit according to claim 6 , further comprising a source for providing a reference signal to said first and second Wheatstone bridges and for providing a reference signal to said analog-to-digital converter.
8. The circuit according to claim 7 , wherein said amplifier circuit is a switching amplifier circuit.
9. The circuit according to claim 6 , wherein said circuit is provided on an implantable structure.
10. The circuit according to claim 9 , wherein said implantable structure is configured for implantation into a heart chamber.
11. An implantable structure comprising a pressure sensor circuit comprising:
a Wheatstone bridge for measuring pressure on the circuit, wherein said Wheatstone bridge produces a first output signal representative of the potential across the Wheatstone bridge and a second output signal representative of said pressure;
an amplifier circuit for amplifying said first and second output signals; an analog-to-digital converter for measuring the ratio of said amplified first and second output signals;
an interface coupled to at least one output of said analog-to-digital converter; and
a source for providing a reference signal to said Wheatstone bridge and for providing a reference signal to said analog-to-digital converter.
12. The implantable structure according to claim 11 , wherein said structure comprises a pressure sensor.
13. The implantable structure according to claim 12 , wherein said structure exhibits a drift of no more than about 1 mmHg/year.
14. The implantable structure according to claim 12 , wherein said structure exhibits little or no drift over a period of from about 1 to about 40 years.
15. The structure according to claim 12 , wherein said structure has a length along an edge of no more than about 500 .mu.m and width of nor more than about 100 μm.
16. The structure according to claim 12 , wherein said structure has a sensitivity sufficient to measure pressure changes in a volume of about +/−1 mmHg.
17. The implantable structure according to claim 11 , wherein said implantable structure is configured for implantation into a heart chamber.
18. An implantable structure comprising a pressure sensor circuit comprising:
a Wheatstone bridge for measuring pressure on the circuit, wherein said Wheatstone bridge produces a first output signal representative of the potential across the Wheatstone bridge and a second output signal representative of said pressure;
an amplifier circuit for amplifying said first and second output signals; an analog-to-digital converter for measuring the ratio of said amplified first and second output signals;
an interface coupled to at least one output of said analog-to-digital converter; and
a source for providing a reference signal to said Wheatstone bridge and for providing a reference signal to said analog-to-digital converter, wherein said implantable structure is configured for implantation into a heart chamber.
19. The implantable structure according to claim 18 , wherein said structure comprises a pressure sensor.
20. The implantable structure according to claim 19 , wherein said structure exhibits a drift of no more than about 1 mmHg/year.
21. The implantable structure according to claim 19 , wherein said structure exhibits little or no drift over a period of from about 1 to about 40 years.
22. The structure according to claim 19 , wherein said structure has a length along an edge of no more than about 500 .mu.m and width of nor more than about 100 μm.
23. The structure according to claim 19 , wherein said structure has a sensitivity sufficient to measure pressure changes in a volume of about +/−1 mmHg.
24. The implantable structure according to claim 18 , wherein said implantable structure is configured for implantation into a heart chamber.