ITBO20060840A1 - METHOD AND MACHINE TO MANIPULATE TOXIC SUBSTANCES - Google Patents

Description

DESCRIPTION

of the patent for industrial invention

by HEALTH ROBOTICS S.R.L.,

of Italian nationality,

with registered office: VIA ALTMANN, 9 / A

39100 BOLZANO (BZ)

Inventors: BALDASSARI Daniele

GABBARRINI Alterino

GIRIBONA Paolo

RAINER Werner

ω ^ Ζ ο ο The present invention relates to a method and 2? 2 to a machine for handling toxic substances.

In particular, the present invention finds

≤ 8 advantageous, but not exclusive application in a machine for the automatic handling of toxic substances used for the automatic preparation of

cytostatic drugs, described in the following description

will make explicit reference without losing it

in general.

There are machines on the market for the automatic handling of toxic substances including a warehouse for containers, such as

bags, bottles and the like, each provided with an opening closed by a respective

pierceable material and containing substances

necessary for the preparation of drugs; a

dosing station, in which there is at least

a seat adapted to hold a relative syringe of

commercial type; and a provided anthropomorphic robot

of a gripping head to pick up a container

from the warehouse, transfer it to the dosing station

at a syringe, and bring it closer

to the syringe needle so that the needle,

piercing the cap, penetrate the container for

be able to inject or withdraw a substance into or, Z or or ° respectively, from the container. Furthermore, in these

machines, an optical sensor of the type a is provided

photocell to facilitate axial alignment

of the mouthpiece with the syringe needle.

The main drawback of such machines is

a considerable difficulty in aligning containers

having a mouth of reduced dimensions due to

the poor accuracy with which the sensor detects the

needle tip position. Very often,

in fact, a terminal portion of the needle can be

bent due to manufacturing defects or damage

caused by the operations of storage and / or

transport and a reduced size of the mouthpiece

often makes correct alignment and, therefore, insertion of the needle into the container impossible.

The object of the present invention is to provide a

method and a machine to manipulate automatically

toxic substances in order to prepare drugs

cytostatics, and an implementing IT product

this method, which are free from the drawbacks

described above and, at the same time, are of

easy and cheap realization.

In accordance with the present invention they are

provided a method and a machine to manipulate

toxic substances, and a computer product Ul_ implementing this method, according to what is claimed by (n S from the attached claims. 1 ® ø .1 The present invention will now be described with

reference to the accompanying drawings, which illustrate one

non-limiting example of implementation, in which:

Figure 1 schematically illustrates a

machine for handling toxic substances;

- figure 2 illustrates a part of the machine

of Figure 1 made according to the present

invention;

Figure 3 illustrates a syringe shown

in a Cartesian reference system and in a

another non-Cartesian reference system;

Figure 4 illustrates a flow diagram of

a method for handling toxic substances in accordance with the present invention, - e

- Figures 5 to 7 illustrate schematically

some steps of the flow chart of Figure 4.

In Figure 1, 1 is generically indicated,

as a whole, a machine for handling toxic substances comprising a magazine 2 (schematically illustrated with a parallelepiped)

for containers 3, such as bags, bottles and the like

for toxic and non-toxic substances necessary for the preparation of drugs, each provided with

Z O

a mouth 4 having an axis 4a and closed by or a respective plug 5 of pierceable material; a _gZΦ

dosing station 6, in which a CD 2 is arranged

Z -g <or dosing unit 7 provided with three seats 8 suitable for holding as many syringes 9 of a commercial type

of various format, i.e. of the type comprising a

body 10 of cylindrical shape, a needle 11 engaged at one end of the body 10, and a plunger 12 which

it slides axially inside the body 10; and a

robot 13 anthropomorphic, which is provided with a

gripping head 14 comprising a gripper member 15

adapted to grasp the containers 3, and an arm 16

articulated with six degrees of freedom designed to support the

head 14 to be able to transfer a container 3 from the magazine 2 to the dosing station 6 in

correspondence to a syringe 9, and bring the

container 3 itself to the needle 11 of this syringe 9 in

so that the needle 11, piercing the cap 5,

penetrate into the container 3.

The machine 1 is also equipped with a unit of

control 17 to control the operation of the robot

13, of the dosage group 7 and of organs of

warehouse handling (not shown) 2. Il

dosing unit 7 and robot 13 are housed

in a sterile compartment (not shown) communicating with

OR

warehouse 2 to prevent germs or microorganisms from contaminating the drugs during their preparation. <Λ £ 7 _ * ai The dosing unit 7 comprises a ο i ζ with platform 18 rotating around a horizontal axis I8a <3⁄4, on which platform 18 is mounted

the three seats 8 for syringes. Each seat 8 comprises

a gripping element 19 integral with the platform

18 to hold the body 10 of the syringe 9 with a

longitudinal axis 9a of the syringe 9 substantially

vertical, and an actuation member 20 for

extract the plunger 12 so as to aspirate one

amount of substance in the syringe 9 o

to push plunger 12 to inject one

substance out of the syringe 9. The drive elements 20 are rigidly connected to each other by

a bar 21 adapted to move vertically along a

straight guide 22 obtained on platform 18. La

rotation of the platform 18 allows you to change

the orientation of the syringes 9 between a position of

withdrawal of the substance, in which the tip of the needle the

is facing up, and an injection position

of the substance, in which the tip of the needle 11 faces

down and which is shown in Figure 1.

The machine also includes a camera

23 analogue black and white fixed focus, which is

z O equipped with a composite video output not illustrated

and is fixedly mounted on the head 14; and a

£ φ computer 24, for example of the CD or Z 3⁄4 PC architecture type, connected to a hospital computer system <s 25 to exchange data relating to the preparation of

drugs, with the camera 23 to acquire the

images detected by it, and with the control unit

17 to control the components of the machine 1 above

described.

With reference to Figure 2, the gripper member

15 of the head 14 comprises two movable jaws 26

along a sliding axis 26a with movement of

mutual approach and distancing for

grasp and, respectively, release the container 3. The camera 23 is mounted on the head 14 with its own optical axis 23a perpendicular to

a plane on which the sliding axis 26a lies.

The computer 24 comprises an image acquisition card 27, which is of the known type

as a "framegrabber" and has a composite video input (not shown) connected to the output

video composition of the camera 23; an interface unit 28, for example a display a

sensitive screen ("touch screen"), to allow

an operator interacting with the machine 1; a processing unit 29, which is adapted to process the data relating to the drugs and the images

- <acquired in order to determine the commands to send

and> or to the control unit 17; and a 5I1-communication unit 30 connected to the control unit

17 and with the hospital IT system 25.

Processing unit 29 is loaded with a control program designed to implement,

when performed on the processing unit 29 itself,

the method for handling toxic substances according to the present invention.

For the sake of simplicity of description, reference will be made hereinafter to an example of manipulation consisting in the injection of a desired quantity of substance from a syringe 9 to a container 3, which syringe 9 is already placed

in its seat 8 with this substance inside

body 10.

In this example, the method is to command

the arm 16 of the robot 13 to pick up the container 3 from the magazine 2 and transfer it to the dosing station 6 and, substantially at the same time, the platform 18 is rotated to

bring the syringe 9 to the injection position,

that is, with the needle 11 facing downwards. To this

On this point, the arm 16 positions the container 3 above or below the needle 11 with the mouth 4 facing upwards; axially aligns the mouth 4 of the

O b container 3 with the needle 11, i.e. it brings the axis 4a 7 y <_s of the mouth 4 substantially to coincide with

a needle axis il; and lifts the container 3 longitudinally towards the needle 11 so that a

a substantial part of the needle 11, piercing the cap 5,

penetrates into the container 3. Finally, the actuating element 20 is lowered to press the plunger 12 into the body 10 of the syringe 9

just enough to inject the desired amount of substance into the container 3.

According to the present invention, the step of axial alignment of the mouth 4 of the container 3 with the needle 11 provides for acquiring two images of the needle 11 from two respective distinct observation points; to process such images to determine the position of the needle tip 11 and the inclination of the needle 11, i.e. the inclination of

an axis of the needle 11 with respect to the axis 9a of the syringe 9; and to operate the arm 16 of the robot 13

so as to correct the position of the head 14, e

therefore of the container 3, as a function of the position

of the needle tip 11 and the inclination of the needle

11. In particular, the processing of the two images SS I essentially consists in determining, for each ω ζ £ of the images, the spatial coordinates of two points 1o ®

Ζ IΝ

<Γ ο along needle 11 and when calculating the position of the

tip of the needle 11 and the inclination of the needle 11 as a function of these coordinates on the basis of the known principle of optical triangulation.

With reference to the drawing of Figure 3, with P

a point is indicated which represents a section of the needle 11 with respect to a Cartesian reference system with three axes X, Y, Z, in which the Z axis is perpendicular to the plane of the drawing and the axis 9a of the

syringe 9 is parallel to the Z axis. Two observation points OT and OS are defined along two respective and distinct framing directions FT and FS orthogonal to the Z axis; the OT observation points

and OS being defined substantially at the same distance from the point P in the respective directions of framing FT and FS. In order to acquire an image from each of the OT and

OS, the arm 16 of the robot 13 moves and rotates,

around the Z axis, the head 14 for positioning the camera 23 first at the observation point OT with

the optical axis 23a parallel to the framing direction FT and afterwards at the observation point OS

with the optical axis parallel to the direction of ≤: z frame FS. C / 3 is φ It is worth noting that the triangulation ø §

5 <<;> sa optics would give optimal results if the FT and FS framing directions were orthogonal to each other.

However, to contain the extent of the movements

of the arm 16 of the robot 13 in such a way as to reduce the overall external dimensions of the sterile compartment, the framing directions FT and FS form a

acute angle. In particular, with reference always

in figure 3, the framing directions FT and FS

form two respective angles a and β e with the Y axis

are orthogonal to two respective framing planes defined, each, by the z axis and by a respective t, s axis orthogonal to the Z axis. The value of the angles a and β is such that their sum (α + β) is less than 90 °, and in particular lower or equal

at 40 °. The coordinates of the point P with respect to the Cartesian axes X and Y are indicated with Xp and Yp and those with respect to the t and s axes are indicated with tp and sp.

The coordinates with respect to the t and s axes can, however, be reported to the Cartesian reference system by means of the following trigonometric transformation:

To determine the inclination of the needle 11, z: §

<8 it is necessary to determine at least two points, which we will indicate

hereinafter with PI and P2, through which the needle passes

11. Note the Cartesian coordinates XI, Yl, ZI del

point Pi and the Cartesian coordinates X2, Y2, Z2 of the

point P2, the inclination is given by the following trigonometric relations:

71 - 72 <Λ>

RX = arctan (3)

Z1 - Z2,

XI- X2

RY = arctan (4)

Z1- Z2

in which RX and RY represent the angles that projections, on the X-Z and Y-Z planes, of a portion of

needle 11 between points P1 and P2 form with the

X and Y axes respectively.

Figure 4 illustrates a flow chart describing the processing of the two acquired images

from the respective observation points OT and OS in order

to determine the position of the tip of the needle 11 and the inclination of the needle 11. The following figures 5, 6

and 7 schematically illustrate some steps of

such processing. Image processing

it is implemented in a portion of said control program made in a programming language known as LabVIEW <®> and compiled, in the environment, Microsoft <®> Windows <®> as a DLL library.

With reference to Figure 4, first of all

the image of the needle 11 is acquired in digital format (block 100), through the image acquisition card 27, after which an area of interest 31 of the irenagine is defined (Figure 5),

ONE S <I> MANG <I> N <I> M i.e. a rectangular portion of the image, N <1> 00 <1> A <lb I> r <ii> oczones. within which portion the needle will be searched

11 (block 101), and an image contrast threshold is adjusted to a minimum value, beyond

which the needle can be detected (block 102).

The area of interest is examined by lines starting from the bottom (z = zi, figure 5) (block 103), e

a scan is made on each line under examination

to search for an edge using a function, known as the "IMAQ Edge Tool", which comes with a library, note

like IMAQ Vision, for the LabVIEW language {block

104). In case an edge is found (exit

SI of block 105), then it is evaluated whether this front

is compatible with the tip of the needle 11, i.e.

if this front is within a compatibility area 32 (Figure 5) defined as a determined rectangular portion of the area of interest 31 in which the LU Z tip of the needle 11 is expected to be found (block 106); otherwise you go to

next line (z = z + l, figure 5) (block 107). In COg Z and if the maximum number of oZ IN lines (zmax) is reached without having found any edge (output l- <8> SI of block 108), then an error message of the type "needle not recognize them "(block 109).

If the edge found is compatible (exit

SI of block 106), then the coordinates of this front are extracted from the image, which corresponds to the first point PI searched and defines the

needle tip 11 (figure 5) (block 110); otherwise

the threshold is increased by a certain amount

(block 111) to adapt the needle search 11 to the image quality and is repeated

examining the area of interest from the first line

(block 103). In the event that the

maximum value of the contrast threshold without having

found a front in the compatibility area (exit

SI of block 112), then a message is produced

error of the type "needle in unexpected position" (block

109).

After determining the coordinates of the point

P1, which represents the tip of the needle 11, comes

determined the second point P2 through which it passes

needle 11.

In particular, it goes to a line that is away

LU _ from the line of the point PI of a predetermined number of OFFSET Z o o ° lines (figure 6) (block 113), the threshold of S z co g contrast is adjusted to a maximum value (block Z • r: ec C32 z - g 114), and the line under examination is scanned <3⁄4 to search for edges using the "IMAQ Edge

Tool "mentioned above (block 115).

Whenever an edge is found (exit

SI of block 116), it is evaluated whether the distance between a

first EF front and a last EL front found in

row under consideration is compatible with the dimensions

transversal of the needle 11, i.e. if this distance is

equal, within a given tolerance, to the diameter

of needle 11 (block 117). In case it doesn't come

no edge found (NO output of block 116)

or the distance between the edges EF and EL is not compatible with the size of the needle 11 (output NO

of block 117), then the contrast threshold is reduced by a determined quantity (block 118) e

the scan of the line in question is repeated (block

115). In case the value is reached

minimum of the contrast threshold without having found

no front or without that the distance between the

edges EF and EL is compatible with the size of the needle 11 (output YES of block 119), then an error message of the type "needle not

Ui recognizable "(block 109). Oo If the distance between the edges EF and EL found coJ in the line under examination is compatible with the dimensions

ϋy 9N of needle 11 (output YES of block 117), then the point P2 is calculated as an intermediate point between

points identified by the EF and EL fronts (figure 7)

(block 120).

It is worth noting that the coordinates of the

points P1 and P2 provided by blocks 110 and 120 are expressed in pixels. Hence, the determination of the

point P2 is followed by a transformation operation

of the coordinates of the points P1 and P2 from pixels to millimeters (block 121) by applying transformation coefficients obtained during a calibration step which will be described below.

The algorithm defined by the blocks numbered 100

121 is repeated for each of the two acquired images (block 122). In this way, from the image acquired from the observation point OT are obtained

the coordinates of the points Pi and P2 with respect to the t-axes

and Z, and from the image acquired from the observation point OS we obtain the relative coordinates

to the t and Z axes. Overall, the coordinates tl, si, Zi are obtained for the point PI and the coordinates

LU _ Z or t2, s2, Z2 for point P2. At this point, come O 2

22 apply expressions (1) and (2) to obtain the co g - <Cartesian coordinates XI and Yl as a function of the ϋ §

z: £ si and tl coordinates and the Cartesian coordinates X2 and Y2 <s as a function of the coordinates s2 and t2 (block 123) and

expressions (3) and (4) are applied to calculate the inclination of the needle 11 in operation

of the coordinates of the two points P1 and P2 (block 124).

As for the calibration step mentioned above, it is performed first

of any drug preparation and plans to acquire three additional 11 needle images of one

syringe 9 fixed in a standard position, for

example housed in a relative seat 8 with the

needle tip the pointing down. One first

of such further images is recorded after having positioned, by means of the arm 16 of the robot

13, the camera 23 in one of the observation points, for example at the point OT, with the axis

optical 23a parallel to the relative direction of framing FT. A second image and a third image are acquired after moving,

again by means of the arm 16, the camera 23 a

first time only along the t axis and a second time

only along the Z axis of respective known quantities in millimeters, keeping the distance from the axis 9a substantially constant. Using the algorithm z and previously described, lo is calculated

co | displacement in pixels of the needle 11 in the second and _ ®

0 .1 in the third image with respect to the needle position? -s 11 recorded in the first image, and making the 1 ratio between the displacements in millimeters and in

pixels, two transformation coefficients are obtained

from pixels to millimeters.

From what has been described above, it is clear

that the axial alignment of the mouth 4 of the container 3 with the needle 11 of the syringe 9 in accordance

with the present invention it is identically applicable in any position the

syringe 9, for example in the withdrawal position

of the substance, in which the syringe 9 is oriented with the tip of the needle 11 upwards. In this situation, in fact, the arm 16 of the robot 13 is controlled to move and rotate the head 14 in such a way

to overturn the container 3 with the mouth 4

facing down and placed over the tip

needle 11, also overturning at the same time the camera 23 mounted above the head 14. Therefore, le

images acquired by the camera 23 show the needle 11 always with the tip pointing m Z a towards the lower part of the image. o ° the main advantage of the machine 1 for £

£ a) handling toxic substances described above is to (D or 3 <= 3⁄4 obtain an axial alignment between the mouth 4

of the container 3 the needle 11 of the syringe 9 of such precision as to allow the insertion of the needle

11 also through mouths 4 with extremely reduced dimensions. Indeed, it is possible to get

an alignment error of less than 0.5mm.

In addition, proper axial alignment allows for

obtain the maximum draft of the needle 11 even if the latter is curved.

Claims (3)

R IV E N D I CA Z I O N I 1.- Method for handling toxic substances including the steps of: pick up and transfer, by means of anthropomorphic manipulation means (13), a container (3) from a warehouse (2) for containers to a station metering device (6), in correspondence with which a metering device (9) equipped with a needle (11) is arranged; the container (3) having a closed mouth (4) by a pierceable element (5); - axially align the opening (4) with LL1 Z the needle (11) by means of such manipulation means (13); - bring the container (3) close to the dispenser (9) by means of the manipulation means I 7 <(13) in such a way o or Z that the needle (11) pierces the pierceable element (5) and enters the container (3) in order to be able to inject or withdraw a substance into or, respectively, from the container (3); and being characterized in that the axial alignment of the mouth (4) with the needle (11) includes the sub-phases of: - acquiring a plurality of images of the needle (il) from at least two distinct observation points (OT, OS); processing such images to determine the position of the needle tip (11); And - operate the manipulation means (13) to correct the position of the opening (4) according to the position of the needle tip (11). 2.- Method according to claim (1), wherein said metering device (9) has a longitudinal axis (9a); the processing of said images providing for determining the inclination of the said needle (11) with respect to the axis (9a); the actuation of manipulation means (13) for correcting the position of said mouth (4) by providing ω | correct this position according to the inclination of the needle 3. A method according to claim 2, in which said metering device (9) has a longitudinal axis (9a); the said plurality of images of the needle (11) being acquired from at least two framing directions (FT, FS) lying on a plane orthogonal to the axis (9a) and passing, each, for a respective of said observation points (OT, OS); the framing directions (FT, FS) forming between them, starting from the observation points (OT, FT), an acute angle. 4.- Method according to claim 2 or 3, where (100) an image in digital from each of said observation points (OT, OS); the said image processing step provides for determining (101-112), from each of the images, first coordinates (si, tl, Zi), with respect to a plane reference system consisting of a plane orthogonal to the relative said direction of framing (OT, OS), of a first point (Pi) passing through said needle (11) and representative the said tip of the needle (11). 5.- Method according to claim 4, wherein LU _ Z S the determination (101-112) of the first coordinates o 2 (si, tl, Zi) comprises the steps of: < (U CD g - define (101), for each image, an area N of interest (31) of the image itself; - perform (102-108) a scan by lines of the area of interest (31) to find a first one forehead compatible with the probable position of the said tip of the needle (11), determine (110) the coordinates of the former front found and define the first coordinates (tl, si, ZI) as the coordinates of this first front. 6. A method according to claim 6, wherein the determination (101-112) of the first coordinates (si, tl, ZI) includes the phases of: - in the event that a first front is found not compatible, increase (111) an image contrast threshold by a predetermined amount and repeat the scan by lines of the image; And if (112) a maximum value of the contrast threshold is reached without having found a first compatible front, produce (109) an error message. 7.- Method according to claim 4 to 6, in which said image processing step provides for determining (113-120), from each of the images, second coordinates (s2, t2, Z2), with respect to said plane reference system, by a second point (P2), passing through said needle (11) and distant, along said axis (9a) of the metering device (9), a predetermined quantity by said first point (PI); the said inclination of the needle (11) being determined as a function of the said first coordinates (si, tl, ZI) and of the second coordinates (s2, t2, Z2). 8. A method according to claim 7, wherein the determination (113-120) of the second coordinates (s2, t2, Z2) includes the phases of: - perform (114-117), on each image, a scan of a line distant a predetermined number of lines (OFFSET) from said point (PI) to find at least two second edges (EF, EL) at a mutual distance compatible with the transversal dimensions of said needle (11); And - calculate (120) the second coordinates (s2, t2, Z2) as coordinates of an intermediate point between the two second edges (EF, EL). 9. A method according to claim 8, wherein the determination (113-120) of the second coordinates (s2, t2, Z2) includes the phases of: if no second front (EF, EL) is found or the distance between the second edges (EF, EL) is not compatible with the rii „cross-sectional dimensions of the needle (il), increase or (118) an image contrast threshold and repeat the scan of said row; if (119) a z: .g <8 minimum value of the contrast threshold is reached without having found any second front (EF, EL) or without that the distance between the second fronts (EF, EL) is compatible with the transversal dimensions of the needle (11), produce (109) an error message. 10 .- IT product that can be loaded into the memory of a computer (24) of a machine (1) to manipulate toxic substances, and designed to implement, when run on said computer (24), the method according to any one of the preceding claims. 11.- Machine for handling toxic substances comprising a dosing station (6), in correspondence with which a doser (9) is arranged equipped with a needle (11); a magazine (2) for storing containers (3), each of which has a respective mouth (4) closed by a pierceable element (5); anthropomorphic handling means (13) adapted to take at least one container (3) from the magazine (2) and to transfer the container (3) to the dosing station (6) in correspondence with the dispenser (9); and control means "a z ω E (17) adapted to control the movements of the manipulation means (13), and being characterized by the fact that it comprises means for acquiring s1-images (23) for acquiring images of the needle (11); And processing means (24), which are connected to the control means (17) for sending commands to the machine and to the image acquisition means (23) to receive the images of the needle (11), and are configured to implement the method according to a of claims 1 to 9. 12.- Machine according to claim 11, in to which said image acquisition means (23) they are mounted on said manipulation means (13). 13. A machine according to Claim 11, wherein said manipulation means comprise a anthropomorphic robot (13), which includes a head (14) for grasping said container (3), and an arm (16) articulated with six degrees of freedom adapted to support the head (14); the said means acquisition devices comprise a camera (23) fixedly mounted on the head (14). 14.- Machine according to claim 13, in wherein said head (14) comprises two jaws (26) movable along a sliding axis (26a) with reciprocal approaching and moving away to grasp and, respectively, release said container (3); the camera (23) comprising an optical axis (23a) and being mounted on said head (14) with the optical axis NEMO S <I> G <I> N <I> MAN (23a) perpendicular to a plane on which the axis <001> N <1> A <ib> r <ii i> eoczons lies. sliding (26a). 15.- Machine according to claim 13 or 14, wherein said video camera (23) is of the white type and fixed focus black and includes a composite video output connected to a corresponding i said processing means (24). p.i .: HEALTH ROBOTICS S.R.L. SIMONE MANGINI Aibo registration No. 1001