Methods and systems for viscoelastic characterization of irregularly shaped anisotropic biological samples

Patent metadata

Field	Value
Publication number	US-9423333-B2
Application number	US-201214003266-A
Country	US
Kind code	B2
Filing date	Mar 27, 2012
Priority date	Apr 1, 2011
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

Methods that extend the utility of standard rotational rheometers for accurate and sensitive viscoelastic characterization of small or small irregularly shaped or small anisotropic samples and systems to implement those methods.

First claim

What is claimed is:

1. A method for viscoelastic characterization of small samples, the method comprising:
(a) locating a sample so that the sample is radially offset from a center of a sample holding section of a conventional parallel plate rotational rheometer; wherein locating the sample comprises placing the sample on a holding component, the sample being placed so that the sample is radially offset from the center of the sample holding section of the conventional parallel plate rotational rheometer;
(b) obtaining geometrical and location properties of the sample by obtaining an image of the sample while placed on the holding component;
(c) obtaining the geometrical and location properties of the sample from the image;
(d) obtaining, from the geometrical and location properties of the sample, a polar moment of inertia for the sample; and
(e) obtaining, from a modulus of elasticity obtained from the conventional parallel plate rotational rheometer, using the polar moment of inertia for the sample, a modulus of elasticity for the sample.

2. The method of claim 1 wherein the sample holding component comprises a glass slide.

3. The method of claim 1 wherein the geometrical and location properties comprise position, size and shape.

4. The method of claim 1 wherein the obtaining the modulus of elasticity for the sample comprises adjusting the modulus of elasticity obtained from the conventional parallel plate rotational rheometer by a ratio of a polar moment of inertia for a test sample that occupies the sample holding section of the conventional parallel plate rotational rheometer from the center to an outer radius of a location of the sample to the polar moment of inertia for the sample.

5. The method of claim 1 further comprising repeating steps a) to c) for another orientation of the sample.

6. An apparatus for viscoelastic characterization of small samples, the apparatus comprising:
a holding component configured such that a sample is radially offset from a center of a sample holding section of a conventional parallel plate rotational rheometer and configured to provide the sample to the conventional parallel plate rotational rheometer;
an imaging component configured to acquire an image of the sample;
an analysis component adapted to obtain, from a geometrical and location properties of the sample, a polar moment of inertia for the sample; and
an adjustment component adapted to obtain, from a modulus of elasticity obtained from the conventional parallel plate rotational rheometer, using the polar moment of inertia for the sample, a modulus of elasticity for the sample.

7. The apparatus of claim 6 wherein the holding component comprises a substantially flat piece of a substantially transparent material dimensioned to be located in the sample holding section of the conventional parallel plate rotational rheometer; and a rod located at substantially the center of substantially flat piece, the rod being adapted to be placed in the sample holding section of the conventional parallel plate rotational rheometer.

8. The apparatus of claim 7 wherein the substantially flat piece comprises an etched portion.

9. The apparatus of claim 6 wherein the imaging component comprises an image acquisition component; and optical components disposed between the sample and the image acquisition component; the optical components being configured to provide an image of the sample to the image acquisition component.

10. The apparatus of claim 9 wherein the optical components comprise a prism disposed to receive an image of the sample and provide the image to the image acquisition component.

11. The apparatus of claim 6 wherein the analysis component comprises:
one or more processors; the one or more processors being operatively connected to the imaging component and receiving an image of the sample from the imaging component; and
computer usable media having computer readable code embodied therein, the computer readable code causing the one or more processors to:
obtain the polar moment of inertia for the sample.

12. The apparatus of claim 11 wherein the computer readable code also causes the one or more processors to obtain a radius for a test sample, the radius being obtained from a number of selected locations on a periphery of the image of the sample.

13. The apparatus of claim 12 wherein the one or more processors are operatively connected to an output of the conventional parallel plate rotational rheometer and receive the modulus of elasticity obtained from the conventional parallel plate rotational rheometer; and wherein the computer readable code also causes the one or more processors to:
obtain of the polar moment of inertia for the test sample; and
adjust the modulus of elasticity obtained from the conventional parallel plate rotational rheometer by a ratio of the polar moment of inertia for the test sample to the polar moment of inertia for the sample; the computer usable media having the computer readable code and the one or more processors constituting the adjustment component.

Assignees

• Cirka Heather A
• Billiar Kristen L
• Worcester Polytech Inst

Inventors

• Cirka Heather A
• Billiar Kristen L

Classifications

• G01N2203/0089

  Biorheological properties · CPC title

• G06T2207/30164

  Workpiece; Machine component · CPC title

• G01N11/14 Primary

  by using rotary bodies, e.g. vane (G01N11/16 takes precedence) · CPC title

• G06T7/606

  Physics · mapped topic

• G06T7/0004

  Industrial image inspection · CPC title