Implantable extracompartmental pressure sensor

Patent metadata

Field	Value
Publication number	US-11122975-B2
Application number	US-201815948187-A
Country	US
Kind code	B2
Filing date	Apr 9, 2018
Priority date	May 12, 2017
Publication date	Sep 21, 2021
Grant date	Sep 21, 2021

Abstract

A miniature, low power electronic pressure sensor with a first, oil-filled chamber to protect its microelectromechanical systems (MEMS) pressure sensitive membrane and a second chamber filled with saline or body fluids connected by tube into an organ in the body, such as an eyeball, that needs pressure sensing, is described. The tube carries pressure from a sensitive area within the organ to the electronic pressure sensor. The pressure sensor may communicate wirelessly with external readers and pass data to a server or other computer. Running alongside the tube is another tube for draining and pressure relief. The tubes, or cannulas, can share an opening into the organ in order to minimize the number of holes needed. The tubes may be molded into a single oval cross section, combined coaxially, or share a lumen for a portion that enters the wall of an organ so as to promote healing.

First claim

What is claimed is:

1. An implantable pressure sensor apparatus comprising:
an electronic pressure sensor with a pressure sensitive membrane;
an oil chamber encapsulating the pressure sensitive membrane, the oil chamber filled with a biocompatible oil and having a pliable membrane on at least one side;
a saline chamber on an opposite side of the pliable membrane from the oil chamber;
a sensing cannula with a lumen extending into the saline chamber;
a drain cannula with a portion adjoining and running parallel with the sensing cannula;
filler wedges within valleys between the sensing cannula and the adjoining drain cannula, the filler wedges, sensing cannula, and drain cannula forming an oval cross section; and
a flow restrictor within the drain cannula.

2. The apparatus of claim 1 wherein the filler wedges extend to an end of the adjoining drain cannula and sensing cannula.

3. The apparatus of claim 2 wherein the end is slanted.

4. The apparatus of claim 1 wherein the filler wedges comprise cured silicone rubber.

5. The apparatus of claim 1 wherein the flow restrictor is proximate a free end of the drain cannula opposite an end with the portion adjoining and running parallel.

6. The apparatus of claim 1 further comprising:
microbeads within the flow restrictor, a packing of the microbeads configured to limit fluid flow.

7. The apparatus of claim 6 further comprising:
an injection port on the flow restrictor configured to allow access by a needle to the microbeads.

8. The apparatus of claim 1 wherein the flow restrictor comprises a mechanical valve.

9. The apparatus of claim 1 further comprising:
a flexible printed circuit board (PCB);
a coil connected with the PCB;
a wireless transmitter connected with the coil; and
an integrated circuit (IC) configured to transmit a pressure reading from the electronic pressure sensor through the wireless transmitter and coil.

10. The apparatus of claim 1 wherein the biocompatible, silicon-compatible oil comprises silicone oil.

11. The apparatus of claim 1 wherein the pliable membrane includes parylene.

12. The apparatus of claim 1 further comprising:
a glass plate suspended above the pliable membrane.

13. The apparatus of claim 1 wherein the saline chamber is comprised of a semi-rigid polymer.

14. An implantable pressure sensor apparatus comprising:
an electronic pressure sensor with a pressure sensitive membrane;
an oil chamber encapsulating the pressure sensitive membrane, the oil chamber filled with a biocompatible oil and having a pliable membrane on at least one side;
a saline chamber on an opposite side of the pliable membrane from the oil chamber;
a glass plate suspended above the pliable membrane;
a sensing cannula with a lumen extending into the saline chamber;
a drain cannula with a portion adjoining and running parallel with the sensing cannula; and
a flow restrictor within the drain cannula.

15. The apparatus of claim 14 further comprising:
filler wedges within valleys between the sensing cannula and the adjoining drain cannula, the filler wedges, sensing cannula, and drain cannula forming an oval cross section.

16. The apparatus of claim 15 wherein the filler wedges extend to an end of the adjoining drain cannula and sensing cannula.

17. The apparatus of claim 16 wherein the end is slanted.

18. The apparatus of claim 15 wherein the filler wedges comprise cured silicone rubber.

19. The apparatus of claim 14 wherein the flow restrictor is proximate a free end of the drain cannula opposite an end with the portion adjoining and running parallel.

20. The apparatus of claim 14 further comprising:
microbeads within the flow restrictor, a packing of the microbeads configured to limit fluid flow.

Assignees

• California Inst Of Techn
• Univ Southern California

Inventors

• Rodger Damien C
• Tai Yu-Chong
• Humayun Mark S
• Shapero Aubrey M
• Agarwal Abhinav
• Emami Azita

Classifications

• A61F9/00781

  Apparatus for modifying intraocular pressure, e.g. for glaucoma treatment (drainage implants in general A61M27/002) · CPC title

• A61M27/00

  Drainage appliance for wounds or the like {, i.e. wound drains, implanted drains} ({negative pressure wound therapy devices A61M1/90;} implements for holding wound open A61B17/02 {; middle ear drainage A61F11/202}) · CPC title

• A61B3/16 Primary

  for measuring intraocular pressure, e.g. tonometers · CPC title

• A61M2205/04

  implanted · CPC title

• A61B2562/12

  Manufacturing methods specially adapted for producing sensors for in-vivo measurements · CPC title