Pressure sensor 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 method for measuring cardiac pressure, the method comprising:
providing a power supply voltage for a number of control chips over two wires, each control chip coupled to one or more pressure sensors;
transmitting a number of bit sequences carrying address information with the power supply voltage over the two wires;
configuring a pressure sensor for measuring cardiac pressure; and
receiving a digital signal indicating a measured cardiac pressure.
2. The method of claim 1 , wherein the pressure sensor includes a Wheatstone bridge.
3. The method of claim 1 , wherein transmitting a number of bit sequences over the two wires involves modulating the power supply voltage with a digital signal.
4. The method of claim 3 , wherein the digital signal is a frequency-shift-keying (FSK) modulated signal.
5. The method of claim 1 , wherein the power supply voltage is provided for approximately 50 μs.
6. A method for measuring cardiac pressure, the method comprising:
receiving a power supply voltage over two wires;
receiving a number of bit sequences carrying address information with the power supply voltage over the two wires;
configuring a pressure sensor for measuring cardiac pressure; and
transmitting a digital signal indicating a measured cardiac pressure.
7. The method of claim 6 , wherein the pressure sensor includes a Wheatstone bridge.
8. The method of claim 7 , further comprising:
applying a reference voltage on the Wheatstone bridge; and
measuring a response voltage from the Wheatstone bridge.
9. The method of claim 8 , wherein the reference voltage is applied to the Wheatstone bridge for approximately 1 μs.
10. The method of claim 9 , further comprising amplifying the measured voltage with an ultra-fast switched-capacitor circuit.
11. An integrated circuit for measuring cardiac pressure, the integrated circuit comprising:
a first terminal;
a second terminal; and
a control circuit coupled to the first and second terminals wherein, during a first time interval, when digital configuration signals are provided from the controller on the first terminal, the control circuit selectively configures a selected pressure sensor, and wherein, during a second time interval, the control circuit administers electrical signals to the pressure sensor and measures a response voltage from the pressure sensor.
12. The integrated circuit of claim 11 , wherein during a third time interval, the control circuit communicates a digital signal indicating the measured voltage through the first and second terminals.
13. The integrated circuit of claim 11 , wherein the first terminal is coupled to a conductor provided in the implanted lead.
14. The integrated circuit of claim 11 , wherein the second terminal is coupled to a conductor provided in an implanted lead.
15. The integrated circuit of claim 11 , wherein the control circuit comprises a clock recovery circuit which recovers a clock signal form received configuration signals.