Implantable substrate sensor with back-to-back electrodes

• US 7,555,328 B2
• Filed: 03/29/2006
• Issued: 06/30/2009
• Est. Priority Date: 09/12/1997
• Status: Expired due to Fees

• Current Assignee: Alfred E. Mann Foundation For Scientific Research
• Original Assignee: Alfred E. Mann Foundation For Scientific Research
• Inventors: Canfield, Lyle Dean, Shah, Rajiv, Schulman, Joseph H., Byers, Charles L., Gord, John C.
• Primary Examiner(s): SCHAETZLE, KENNEDY
• Application Number:
  US11/392,163
• Publication Number:
  US 20060229694A1
• Time in Patent Office: 1,189 Days
• Field of Search: None
• US Class Current: 600/347
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 29/0657 characterised by the shape of the body
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/19041 being a capacitor

Abstract

An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensor may be placed back-to-back, with the electrodes facing outward. As required, capacitors that form part of the sensor'"'"'s electronic circuits are formed on the substrate by placing metalization layers and a dielectric in vacant areas of the substrate surface.

Claims

1. An implantable sensor assembly, comprising:

a first sensor having a first surface and a second surface facing different directions, the first surface having an electric circuit and the second surface having at least one electrode;

a second sensor having a first surface and a second surface facing different directions, the first surface having an electric circuit and the second surface having at least one electrode, the first surface of the second sensor being aligned with and directly opposing the first surface of the first sensor such that the second surfaces of the first and second sensors face out from the sensor assembly.

2. The implantable sensor assembly recited in claim 1, wherein the electrodes convert a sensed parameter to a detectable signal.

3. The sensor assembly recited in claim 2, wherein the electric circuits comprises circuits for processing the detectable signal.

4. The implantable sensor assembly recited in claim 1, wherein current flowing through the electrodes electrochemically reacts with at least one substance in proximity to exposed surface areas of the electrodes.

5. The implantable sensor assembly recited in claim 4, wherein the at least one substance is oxygen.

6. The sensor assembly recited in claim 1, wherein the electrodes apply an electrical pulse to a substance in contact with the electrodes.

7. The sensor assembly recited in claim 6, wherein the substance is living tissue.

8. The sensor assembly recited in claim 1, wherein the electric circuit of the first sensor is connected to the at least one electrode of the first sensor through the first sensor, and the electric circuit of the second sensor is connect to the at least one electrode of the second sensor through the second sensor.

9. The sensor assembly recited in claim 1, further comprising an outer casing enclosing the first and second sensors, the outer casing having at least one window pocket formed therein in proximity to an exposed surface area of the second surface of the first sensor.

10. A sensor assembly, comprising:

a first substrate sensor having a first surface and a second surface facing different directions, the second surface having at least one electrode for converting a sensed parameter to a detectable signal, and the first surface having an electric circuit for processing said detectable signal;

a second substrate sensor having a first surface and a second surface facing different directions, the second surface having at least one electrode for converting a sensed parameter to a detectable signal, and the first surface having an electric circuit for processing said detectable signal; and

,

at least a portion of the first surface of the second substrate sensor being directly opposed to at least a portion of the first surface of the first substrate sensor such that the second surfaces of the first and second substrate sensors face out from the sensor assembly in substantially opposite directions.

11. The sensor assembly recited in claim 10, wherein current flowing through the electrodes electrochemically reacts with at least one substance in proximity to the electrodes.

12. The sensor assembly recited in claim 11, wherein the at least one substance is oxygen.

13. The sensor assembly recited in claim 10, wherein the first substrate sensor is fixed stationary relative to the second substrate sensor.

14. The sensor assembly recited in claim 10, further comprising an outer casing enclosing the first and second substrate sensors, the outer casing having at least one window pocket formed therein in proximity to an exposed surface area of the electrode surface of the first substrate sensor.

15. A sensor assembly, comprising:

a first substrate sensor having an electrode surface and a circuit surface facing in different directions, said circuit surface comprising an electric circuit on a semiconductor substrate;

a second substrate sensor having an electrode surface and a circuit surface facing in different directions, said circuit surface comprising an electric circuit on a semiconductor substrate; and

,

at least a portion of the circuit surface of the second substrate sensor facing at least a portion of the circuit surface of the first substrate sensor such that the electrode surfaces of the first and second substrate sensors face out from the sensor assembly in substantially opposite directions.

16. The sensor assembly recited in claim 15, wherein the electrode surfaces include electrodes for converting a sensed parameter to a detectable signal.

17. The sensor assembly recited in claim 15, wherein current flowing through the electrodes electrochemically reacts with at least one substance in proximity to the electrodes.

18. The sensor assembly recited in claim 17, wherein the at least one substance is oxygen.

19. The sensor assembly recited in claim 15, wherein the electrodes apply an electrical pulse to a substance in contact with the electrodes.

20. The sensor assembly recited in claim 19, wherein the substance is living tissue.

21. The sensor assembly recited in claim 15, further including an outer casing enclosing the first and second substrate sensors, the outer casing having at least one window pocket formed therein in proximity to an exposed surface area of the electrode surface of the first substrate sensor.

22. The sensor assembly recited in claim 21, further including at least one additional window pocket formed in the outer casing in proximity to an exposed surface area of the electrode surface of the second substrate sensor.

23. The sensor assembly of claim 21, wherein the outer casing is a membrane.

24. An implantable sensor lead comprising:

a proximal end connected to a controller;

a distal end; and

at least one sensor assembly within the sensor lead controlled by the controller, the at least one sensor assembly including;

a first substrate sensor having a first surface and a second surface facing different directions, the first surface having an electric circuit and the second surface having at least one electrode;

a second substrate sensor having a first surface and a second surface facing different directions, the first surface having an electric circuit and the second surface having at least one electrode; and

,

at least a portion of the first surface of the second substrate sensor being opposed to at least a portion of the first surface of the first substrate sensor such that the second surfaces of the first and second substrate sensors face out from the sensor assembly in substantially opposite directions.