Method and machine for manipulating toxic substances

• US 8,404,492 B2
• Filed: 11/21/2007
• Issued: 03/26/2013
• Est. Priority Date: 11/22/2006
• Status: Active Grant

• Current Assignee: Omnicell Srl (Omnicell Incorporated)
• Original Assignee: Health Robotics S.r.l (Omnicell Incorporated)
• Inventors: Baldassari, Daniele, Gabbarini, Alferino, Giribona, Paolo, Rainer, Werner
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Handy, Dwayne K
• Application Number:
  US12/516,149
• Publication Number:
  US 20100021348A1
• Time in Patent Office: 1,952 Days
• Field of Search: 436/180, 436/174, 422/501, 422/509, 422/512, 422/560, 702/31
• US Class Current: 436/180
• CPC Class Codes: G06T 1/0014 Image feed-back for automatic industrial control, e.g. robot with camera robots B25J19/023
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

In a machine for manipulating toxic substances, an anthropomorphic robot transfers a container, which has a mouth closed by a cap made of perforable material, from a magazine for containers to a dosage station, set in which is a syringe provided with a needle, axially aligns the mouth with the needle, correcting the position of the mouth according to the position of the tip of the needle obtained from processing a number of images of the needle acquired from at least two distinct observation points, and finally approaches the container to the syringe in such a way that the needle perforates the cap and penetrates into the container to be able to inject or extract a substance into or out of the container.

Claims

1. A method for manipulating toxic substances, the method comprising the steps of:

by using anthropomorphic manipulation means, taking a container from a magazine for containers and transferring it to a dosage station, set in which is a doser having a longitudinal axis and provided with a needle;

the container presenting a mouth closed by a perforable element;

axially aligning the mouth with the needle via the manipulation means;

approaching, via the manipulation means, the container to the doser in such a way that the needle perforates the perforable element and penetrates into the container to be able to inject a substance into the container or draw a substance therefrom;

and being characterized in that the step of axially aligning the mouth with the needle comprises the steps of;

acquiring a plurality of images of the needle from at least two distinct observation points and from at least two directions of framing lying on a plane orthogonal to said longitudinal axis, the directions of framing passing, each, through a respective one of said observation points in such a way as that an acute angle is formed between the directions of framing;

processing said images for determining the position of the tip of the needle and the inclination of the needle with respect to said longitudinal axis; and

actuating the manipulation means for correcting the position of the mouth according to the position of the tip of the needle and the inclination of the needle.

2. The method according to claim 1, wherein said step of acquiring a plurality of images of the needle envisages acquiring an image in digital format from each of said observation points;

said step of image processing comprising the step of determining, from each image, first coordinates for a first point that defines said position of the tip of the needle with respect to a reference system defined on a plane orthogonal to said direction of framing.

3. The method according to claim 2, wherein said step of determining, from each image, first coordinates comprises the steps of:

defining an area of interest of the image;

carrying out a scan on each row of the area of interest to find a first edge compatible with a likely position of said tip of the needle; and

determining the coordinates of the first edge found, the first coordinates being defined as a function of the coordinates of said first edge.

4. The method according to claim 3, wherein said step of determining, from each image, first coordinates comprises the steps of:

in the case where a first non-compatible edge is found, increasing a contrast threshold of the image by a pre-set amount and repeating the scan of the image row by row; and

in the case where a maximum value of the contrast threshold is reached without a first compatible edge having been found, producing an error message.

5. The method according to claim 2, wherein said step of image processing comprises the step of determining, from each image, second coordinates, with respect to said reference system, of a second point, through which said needle passes and which is located at a pre-set distance from said first point along said longitudinal axis;

said step of determining the inclination of said needle with respect to the longitudinal axis envisaging determining said inclination as a function of said first coordinates and the second coordinates.

6. The method according to claim 5, wherein determining, from each image, second coordinates comprises the steps of:

carrying out a scan of a row that is distant by a pre-set number of rows from said first point to find at least two second edges set at a distance apart compatible with the transverse dimensions of said needle; and

calculating the second coordinates as coordinates of an intermediate point between the two second edges.

7. The method according to claim 6, wherein determining, from each image, second coordinates comprises the steps of:

in the case where no second edge is found or else the distance between the second edges is not compatible with the transverse dimensions of the needle, reducing a contrast threshold of the image and repeating the scan of said row;

in the case where a minimum value of the contrast threshold is reached without any second edge having been found or else without the distance between the second edges being compatible with the transverse dimensions of the needle, producing an error message.

8. The method according to claim 2, wherein said image in digital format is constituted by a matrix of pixels;

determining, from each image, first coordinates comprising the steps of;

defining an area of interest of the image;

seeking, within each row of pixels of the area of interest in a pre-set search direction, a pair of pixels constituted by a first pixel and by a last pixel that have an intensity higher than a pre-set intensity threshold;

determining a shape of the tip of the needle on the basis of a linear interpolation of the position, in the area of interest, of the pairs of pixels found;

selecting, from among the pairs of pixels found, a first pair of pixels that remains substantially within said shape and that is positioned on a row of pixels compatible with a likely position of said tip of the needle;

said first coordinates being defined as a function of first pair of pixels.

9. The method according to claim 8, wherein said tip of the needle faces downwards;

said first pair of pixels being positioned, with respect to all the other said pairs of pixels within said shape, on the lowest row of pixels.

10. The method according to claim 8, wherein determining a shape of the tip of the needle comprises:

determining a first straight line and a second straight line via linear interpolation of the positions in the area of interest of the first pixels and, respectively, of the last pixels of all the pairs of pixels found;

said shape being defined by said straight lines.

11. The method according to claim 10, wherein determining a shape of the tip of the needle comprises:

eliminating, from the pairs of pixels found, those pairs of pixels that fall outside of said shape and that are at a distance, along the respective said row of pixels, from said straight lines by a pre-set amount; and

repeating the determination of the straight lines.

12. The method according to claim 5, wherein said image in digital format is constituted by a matrix of pixels;

said step of image processing comprising the steps of;

defining, for each image, an area of interest of the image;

seeking, within each row of pixels of the area of interest in a pre-set search direction, a pair of pixels constituted by a first pixel and by a last pixel that have an intensity higher than a pre-set intensity threshold; and

determining a first straight line and a second straight line, by linearly interpolating the positions in the area of interest of the first pixels and, respectively, of the last pixels of all the pairs of pixels found;

said step of determining, from each image, second coordinates comprising the steps of;

calculating a third straight line as vector sum of the directions identified by the first and second straight lines; and

determining the second coordinates as a function of an intersection of the third straight line with a row of pixels that is distant by a pre-set number of rows from said first point.

13. A non-transient computer readable storage medium having encoded thereof a program comprising software code portions capable of implementing, when the computer program is run on a computer of a machine for manipulating toxic substances, the method according to claim 1.

14. A machine for manipulating toxic substances comprising:

a dosage station, set in which is a doser provided with a needle;

a magazine for storing containers, each of which has a respective mouth closed by a perforable element;

anthropomorphic manipulation means designed to pick up at least one container from the magazine and to transfer the container into the dosage station to a point corresponding to the doser; and

control means designed to control the movements of the manipulation means;

the machine being characterized in that it comprises;

image-acquisition means for acquiring images of the needle; and

processing means, which are connected to the control means for sending commands to the machine and to the image-acquisition means for receiving the images of the needle, and are configured for implementing the method according to claim 1.

15. The machine according to claim 14, wherein said image-acquisition means are mounted on said manipulation means.

16. The machine according to claim 14, wherein said manipulation means comprise an anthropomorphic robot, which comprises a gripping head designed to grip said container, and an articulated arm with six degrees of freedom designed to support said head;

said image-acquisition means comprising a telecamera mounted in a fixed way on the head.

17. The machine according to claim 16, wherein said head comprises two jaws mobile along an axis of sliding with a movement of mutual approach and recession for gripping and, respectively, releasing said container;

the telecamera comprising an optical axis and being mounted on said head with the optical axis perpendicular to a plane on which the axis of sliding lies.

18. The machine according to claim 16, wherein said telecamera is of a black-and-white type with fixed focus and comprises a video-composite output connected to a corresponding input of said processing means.