Biodegradable pressure sensor

Patent metadata

Field	Value
Publication number	US-2021127998-A1
Application number	US-201816491614-A
Country	US
Kind code	A1
Filing date	Mar 14, 2018
Priority date	Mar 14, 2017
Publication date	May 6, 2021
Grant date	—

Abstract

A biodegradable pressure sensor for measuring vital physiological pressures and for preventing the buildup of dangerous internal forces in impaired organs. The pressure sensor is constructed by depositing Mg or Mo on both sides of a PLLA film. This layered configuration (Mg/PLLA/Mg) or (Mo/PLLA/Mo) may then be encapsulated by layers of high molecular weight PLA. These materials are biodegradable such that after implantation, the sensor does not require invasive removal surgery that can damage directly interfaced tissues.

First claim

What is claimed is:

1 . An implantable pressure sensor comprising:
a first layer of a biodegradable metal; a second layer of a polymer film positioned on top of the first layer of biodegradable metal; a third layer of a biodegradable metal positioned on top of the second layer of the polymer film; a fourth layer of a polymer film positioned on top of the third layer of biodegradable metal; a fifth layer of a biodegradable metal positioned on top of the fourth layer of the polymer film; and an electrode extending from the first layer of biodegradable metal, the third layer of biodegradable metal, and the fifth layer of biodegradable metal; and a biodegradable polymer layer encapsulating the first layer, the second layer, the third layer, the fourth layer, and the fifth layer, and wherein the electrodes are connectable to an electronic circuit for measuring pressure exerted on the biodegradable polymer layer.

2 . The pressure sensor of claim 1 , wherein the biodegradable metal is molybdenum.

3 . The pressure sensor of claim 1 , wherein the biodegradable metal is magnesium.

4 . The pressure sensor of claim 1 , wherein the biodegradable polymer layer comprises PLA.

5 . The pressure sensor of claim 1 , wherein each of the layers of the polymer film comprises a poly-lactic acid having a high molecular weight.

6 . The pressure sensor of claim 1 , wherein at least one layer of the polymer film comprises a highly piezoelectric biodegradable polymer film.

7 . The pressure sensor of claim 6 , wherein the highly piezoelectric biodegradable polymer film comprises PLLA, and wherein the pressure sensor has a functional lifetime proportional to an amount of PLLA included in the polymer film or a molecular weight of each PLLA layer included in the polymer film.

8 . The pressure sensor of claim 7 , wherein the functional life time of the pressure sensor increases as the amount or thickness of the biodegradable polymer layer increases.

9 . The pressure sensor of claim 7 , wherein the functional life time of the pressure sensor increases as the molecular weight of the biodegradable polymer layer increases.

10 . The pressure sensor of claim 1 , wherein the pressure sensor is configured to function as a sensitive multi-layer pressure transducer.

11 . The pressure sensor of claim 1 , wherein the pressure sensor is configured to output a charge in response to an applied pressure.

12 . The pressure sensor of claim 1 , wherein the pressure sensor has a size of approximately 0.5 cm×0.5 cm×0.02 cm.

13 . The pressure sensor of claim 1 , wherein the electronic circuit comprises an amplifier connected to the pressure sensor, wherein the amplifier is configured to convert a charge from the pressure sensor into a voltage signal and output the voltage signal to an electronic device.

14 . The pressure sensor of claim 1 , wherein the pressure sensor is configured to sense pressure within a range of approximately 1-50 mmHg.

15 . A biodegradable system comprising:
one or more magnesium wires encapsulated by poly-lactic acid; and a biodegradable piezoelectric device connected to the one or more magnesium wires, the biodegradable piezoelectric device including
a first magnesium electrode,
a second magnesium electrode, and
a polymer film positioned between the first magnesium electrode and the second magnesium electrode,
wherein the biodegradable piezoelectric device is encapsulated by a biodegradable polymer.

16 . The biodegradable system of claim 15 , wherein the biodegradable piezoelectric device includes at least one selected from a group consisting of a biodegradable piezoelectric sensor, a biodegradable piezoelectric actuator, and a biodegradable piezoelectric energy harvester.

17 . The biodegradable system of claim 15 , wherein each of the plurality of layers of the polymer film is formed from a poly-lactic acid having a high molecular weight.

18 . The biodegradable system of claim 15 , wherein the polymer film includes at least one layer of a highly piezoelectric biodegradable polymer film.

19 . The biodegradable system of claim 18 , wherein the biodegradable piezoelectric device has a functional lifetime proportional to at least one selected from a group consisting of an amount of highly piezoelectric poly-L-lactic film layers included in the polymer film and a molecular weight of each highly piezoelectric poly-lactic film layer included in the polymer film.

20 . The biodegradable system of claim 19 , wherein the functional life time of the biodegradable piezoelectric device increases as the amount or thickness of poly-lactic film layers encapsulating the sensor increases.

21 . The biodegradable system of claim 19 , wherein the functional life time of the biodegradable piezoelectric device increases as the molecular weight of each encapsulating polylactic film layers included in the sensor increases.

22 . The biodegradable system of claim 15 , wherein the polymer film includes two layers of a highly piezoelectric poly-L-lactic film. The biodegradable system of claim 15 , wherein the biodegradable piezoelectric device is configured to function as a sensitive multi-layer pressure transducer.

24 . The biodegradable system of claim 15 , wherein the biodegradable piezoelectric device is configured to output a charge in response to a pressure applied to the biodegradable piezoelectric device.

25 . The biodegradable system of claim 15 , wherein the biodegradable piezoelectric device has a size of approximately 0.5×0.5×0.02 cm.

26 . The biodegradable system of claim 15 , further comprising a charge amplifier circuit connected to the biodegradable piezoelectric device, wherein the charge amplifier circuit is configured to convert a charge from the biodegradable piezoelectric device into a voltage signal and output the voltage signal to an electronic device.

27 . The biodegradable system of claim 15 , wherein the biodegradable piezoelectric device is configured to sense pressure within a range of approximately 1-50 mmHg.

28 . A biodegradable system comprising:
one or more molybdenum wires encapsulated by poly-lactic acid; and a biodegradable piezoelectric device connected to the one or more molybdenum wires, the biodegradable piezoelectric device including
a first molybdenum electrode,
a second molybdenum electrode, and
a polymer film positioned between the first molybdenum electrode and the second molybdenum electrode,
wherein the biodegradable piezoelectric device is encapsulated by a biodegradable polymer.

29 . The biodegradable system of claim 28 , wherein the biodegradable piezoelectric device includes at least one selected from a group consisting of a biodegradable piezoelectric sensor, a biodegradable piezoelectric actuator, and a biodegradable piezoelectric energy harvester.

30 . The biodegradable system of claim 28 , wherein each of the plurality of layers of the polymer film is formed from a poly-lactic acid having a high molecular weight.

31 . The biodegradable system of claim 28 , wherein the polymer film includes at least one layer of a highly piezoelectric biodegradable polymer film.

32 . The biodegradable system of claim 31 , wherein the biodegradable piezoelectric device has a functional lifetime proportional to at least one selected from a

Assignees

• Univ Connecticut

Inventors

• Nguyen Thanh Duc
• Curry Eli

Classifications

• A61L2420/08

  Coatings comprising two or more layers · CPC title

• A61B2562/0261

  Strain gauges · CPC title

• A61L31/148

  Materials at least partially resorbable by the body · CPC title

• A61B2562/04

  Arrangements of multiple sensors of the same type · CPC title

• A61B5/03 Primary

  Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure {; Measuring pressure in body tissues or organs (determining bladder or urethral pressure A61B5/205)} · CPC title