Contact-angle measurement method, contact-angle measurement device, bioprosthetic-member inspection device, and storage medium

Patent metadata

Field	Value
Publication number	US-10226202-B2
Application number	US-201414907941-A
Country	US
Kind code	B2
Filing date	Oct 15, 2014
Priority date	Oct 30, 2013
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

This contact-angle measurement method is a contact-angle measurement method for measuring a contact angle (γ) between a droplet that is supplied to a sample curved surface and the sample curved surface. This method includes an apparent contact-angle calculation step of calculating an apparent contact-angle (α) of the droplet by using a captured image of the droplet supplied to the sample curved surface and the sample curved surface; an inclination angle calculation step of calculating an inclination angle (β) of the sample curved surface at an outer periphery portion of a contact portion between the droplet and the sample curved surface by using the captured image; and a contact-angle calculation step of calculating the contact angle (γ) by correcting the apparent contact angle (α), using the inclination angle (β).

First claim

The invention claimed is:

1. A contact-angle measurement method for measuring hydrophilic properties of a bioprosthetic, the method comprising:
dripping a droplet on to a curved surface of the bioprosthetic, wherein the curved surface of the bioprosthetic is a concave curved surface having a curvature radius Rb;
capturing an image of the droplet on the curved surface of the bioprosthetic;
calculating an apparent contact-angle α of the droplet and the curved surface of the bioprosthetic based on the image;
calculating an inclination angle β of the curved surface of the bioprosthetic at an outer periphery portion of a contact portion between the droplet and the curved surface of the bioprosthetic based on the image;
calculating a contact angle γ by adding the apparent contact angle α to the inclination angle β of the curved surface of the bioprosthetic; and
determining the hydrophilic properties of the bioprosthetic based on the contact angle γ.

2. The method according to claim 1 ,
wherein the apparent contact angle α is an angle formed by: a plane that includes a tangent line to an outer surface of the droplet at a given point on the outer periphery portion, and that is in contact with the outer surface; and a plane that includes the outer periphery portion.

3. The method according to claim 1 ,
wherein the inclination angle β is an angle formed by: a plane that includes a tangent line to the curved surface of the bioprosthetic at a given point on the outer periphery portion, and that is in contact with the curved surface of the bioprosthetic; and a plane that includes the outer periphery portion.

4. The method according to claim 1 , further comprising:
calculating a curvature radius Ra of an outer surface of the droplet by using a curvature radius C of the outer periphery portion, a volume V 0 of the droplet, and the curvature radius Rb of the curved surface of the bioprosthetic, prior to the calculating the apparent contact-angle,
wherein, in the calculating the apparent contact-angle, the apparent contact angle α is calculated by using the curvature radius Ra and the curvature radius C.

5. The method according to claim 4 ,
wherein the curvature radius Ra of the outer surface is calculated by using Formulas (a), (b), and (c):
Va =(4π/3) Ra 3 −(π/3){( Ra 2 −C 2 ) (1/2) +Ra} 2 {3 Ra −( Ra 2 −C 2 ) (1/2) −Ra};   (a)

Vb =(4π/3) Rb 3 −(π/3){( Rb 2 −C 2 ) (1/2) +Rb} 2 {3 Rb −( Rb 2 −C 2 ) (1/2) −Rb }; and  (b)

V 0= Va+Vb (when the curved surface of the bioprosthetic is concave) or V 0= Va−Vb (when the curved surface of the bioprosthetic is convex),  (c)

where Va denotes a volume of a first region that is surrounded by: a plane that includes the outer periphery portion; and the outer surface of the droplet, and Vb denotes a volume of a second region that is surrounded by: the plane that includes the outer periphery portion; and the curved surface of the bioprosthetic.

6. The method according to claim 1 ,
wherein in the calculating the inclination angle, the inclination angle β is calculated by using a curvature radius C of the outer periphery portion and the curvature radius Rb of the curved surface of the bioprosthetic.

7. The method according to claim 4 ,
wherein the curvature radius C of the outer periphery portion is calculated based on the image.

8. The method according to claim 1 ,
wherein a volume V 0 of the droplet is set to 0.5μ liters to 3.0μ liters.

9. A measurement device for measuring hydrophilic properties of a bioprosthetic, the measurement device comprising:
a camera;
a drip unit that releases a droplet of a predetermined size;
a memory; and
a processor communicatively coupled to the camera, the drip unit and the memory,
wherein the processor:
causes the drip unit to release the droplet,
captures, using the camera, an image of the droplet on a curved surface of the
bioprosthetic, wherein the curved surface of the bioprosthetic is a concave curved surface having a curvature radius Rb,
calculates an apparent contact-angle α of the droplet and the curved surface of the bioprosthetic based on the image;
calculates an inclination angle β of the curved surface of the bioprosthetic at an outer periphery portion of a contact portion of the droplet and the curved surface of the bioprosthetic based on the image,
calculates the contact angle γ by adding the apparent contact angle α using the inclination angle β, and
determines the hydrophilic properties of the bioprosthetic based on the contact angle γ.

10. The measurement device according to claim 9 ,
wherein the hydrophilic properties include a wettability of the curved surface of the bioprosthetic.

11. A contact-angle measurement method for measuring hydrophilic properties of a bioprosthetic, the method comprising:
dripping a droplet on to a curved surface of the bioprosthetic, wherein the curved surface of the bioprosthetic is a convex curved surface having a curvature radius Rb;
capturing an image of the droplet on the curved surface of the bioprosthetic;
calculating an apparent contact-angle α of the droplet and the curved surface of the bioprosthetic based on the image;
calculating an inclination angle β of the curved surface of the bioprosthetic at an outer periphery portion of a contact portion between the droplet and the curved surface of the bioprosthetic based on the image;
calculating a contact angle γ by subtracting the inclination angle β of the curved surface of the bioprosthetic from the apparent contact angle α; and
determining the hydrophilic properties of the bioprosthetic based on the contact angle γ.

12. A measurement device for measuring hydrophilic properties of a bioprosthetic, the measurement device comprising:
a camera;
a drip unit that releases a droplet of a predetermined size;
a memory; and
a processor communicatively coupled to the camera, the drip unit and the memory,
wherein the processor:
causes the drip unit to release the droplet,
captures, using the camera, an image of the droplet on a curved surface of the bioprosthetic, wherein the curved surface of the bioprosthetic is a convex curved surface having a curvature radius Rb,
calculates an apparent contact-angle α of the droplet and the curved surface of the bioprosthetic based on the image;
calculates an inclination angle β of the curved surface of the bioprosthetic at an outer periphery portion of a contact portion of the droplet and the curved surface of the bioprosthetic based on the image,
calculates the contact angle γ by subtracting the inclination angle β from the apparent contact angle α, and
determines the hydrophilic properties of the bioprosthetic based on the contact angle γ.

13. The method according to claim 11 ,
wherein the apparent contact angle α is an angle formed by: a plane that includes a tangent line to an outer surface of the droplet at a given point on the outer periphery portion, and that is in contact with the outer surface; and a plane that includes the outer periphery portion.

14. The method according to claim 11 ,
wherein the inclination angle β is an angle formed by: a plane that includes a tangent line to the curved surface of the bioprosthetic at a given point on the outer periphery portion, and that is in contact with the curved surface of the bioprosthetic; and a plane that includes the outer periphery portion.

15. The method according to claim 11 , further comprising:
calculating a curvature radius Ra of an outer surface of the droplet by using a curvature radius C of the outer periphery portion, a volume V 0

Assignees

• Kyocera Medical Corp
• Kyocera Corp

Inventors

• Takeshita Yohei
• Muranaka Akio
• Utsumi Kiyotaka

Classifications

• G01B11/255

  for measuring radius of curvature {(measuring diameter G01B11/08)} · CPC title

• G01B11/26

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• A61F2/468

  Testing instruments for artificial joints (for testing non-implantable prostheses A61F2/76) · CPC title

• G06T7/20

  Analysis of motion (motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51) · CPC title

• G01N13/02 Primary

  Investigating surface tension of liquids · CPC title