JPWO2019145487A5 - - Google Patents

Description

The present invention relates to surgery on the eye, more specifically
- surgery on the anterior part of the eye such as cataracts (at the level of the lens), and/or - refractive surgery (at the level of the cornea), and/or - surgery intended to treat glaucoma or other retinal lesions. the general technical field of treatment of ocular lesions by using therapeutic devices intended to perform

More specifically, the present invention provides an ocular lesion treatment system mounted on an articulated robotic arm to allow movement of the articulated robotic arm along three orthogonal axes X, Y and Z. A device and method for controlling movement.

The present invention generally provides that when a therapeutic device operates superficially or deep within the eye by physical agents (e.g., light waves, ultrasound, microwaves, etc.), it reaches the target without damaging adjacent structures. In order to do so, the path must be precisely controlled.

The invention will now be described with reference to a treatment instrument comprising an articulated robotic arm incorporating a system for femtosecond laser cutting of human or animal tissue such as the cornea or lens.

However, it will be appreciated by those skilled in the art that the invention described below may be used to control movement of articulated robotic arms incorporating any other type of system for treating ocular lesions. is quite clear.

There are many therapeutic equipment items with lasers for the treatment of ocular lesions. In this case the laser is used as an optical scalpel.

Such lasers can make deep incisions in the clear tissue of the eye without the use of surgical instruments. Such lasers have the advantage of being rapid and well tolerated, among other advantages of eliminating manual surgery that is operator dependent.

Surgery performed with lasers is thus highly precise and repeatable. It also provides a guarantee of safety that cannot be achieved with actions performed by a human operator, and as a result, the use of lasers allows the consideration of some degree of automated surgery, where machines perform surgery instead of the operator. Carry out the surgical procedure.

In order for a laser-equipped therapeutic device to carry out the steps of a therapeutic procedure, two important steps must be performed beforehand:
(i) Attach the treatment device to the eye to prevent movement of the eye during the treatment procedure and to align the axis of the eye with the machine reference frame.
In this manner, the machine and eye are aligned and secured to each other, and treatment can be safely initiated without risk of deformation or movement during the treatment procedure.
(ii) OCT (optical coherence tomography) or Scheimpflug (visible light mapping) or UBM (ultrasonic biomicroscopy) to delineate the area reached by the laser light so as to be able to cut or fragment this area; An integrated imaging system, such as a mold, maps the intraocular structures of the patient's eye.

In order to carry out step (i), it is necessary to position against the patient's eye a fixation member provided with a suction ring capable of sucking the patient's eye and holding it firmly in place. .

Currently, during stages (i) and (ii) (and then during the treatment stage), all therapeutic instruments that operate within the eye and require fixation of the eyeball are manually operated by the operator. A securing member is provided.

Such therapeutic devices have many drawbacks.
- The manual positioning of the fixation member is subject to some variability, which depends on many factors. The quality of positioning of the fixation members, among other things, varies from operator to operator.
It is known that this induces variations in the fixation state of the patient and the quality of treatment is highly dependent on the quality of positioning of the fixation members.
- The time required by the operator (e.g. a surgeon) to position the fixation elements is very valuable and can therefore be allocated to the machine in a more precise, repeatable manner and at very low cost. doing so is very expensive.
- Manipulation of the fixation elements may be suboptimal for the operator, and various obstacles impede the ability to observe the eye and know if the fixation elements are correctly positioned. Because there are so many, it is often difficult to do.
- The ability of the operator to judge the proper positioning of the fixation elements of the eye, the ability to see, which must be based on indications using criteria in space (level of centering, presence of tilt, presence of rotation, etc.) This is considerably less than the ability of machines equipped with sensors and imaging systems capable of correcting X, Y or Z or trim positioning defects while using level definitions.
- Depending on the delicacy of the operator, the patient may experience discomfort, injury, or improper positioning of the fixation members that may compromise the effectiveness of the treatment.

The object of the present invention is to propose an intelligent autonomous system with the ability to automate the steps of robot locomotion, vision, sensors, the ability to interpret the images created by the embedded vision, and the positioning of the eye fixation member. That is.

To this end, the present invention provides a device for controlling movement of an ophthalmic treatment device comprising:
The therapeutic device comprises:
- a support arm, the free end of which is intended to align with the tissue of the human or animal eye, the arm being bifurcated along three orthogonal axes X, Y and Z; each articulated to allow movement of the free end of the arm,
- the X-axis defines a horizontal longitudinal direction,
The Y axis defines the horizontal lateral direction, and together with the X axis defines the horizontal plane XY,
a support arm, the Z-axis of which defines a vertical direction and is perpendicular to the horizontal plane XY;
- an acquisition system mounted on said arm for acquisition of a measurement pair, said measurement pair comprising:
- an image of tissue of the eye;
an acquisition system comprising a signal representative of the vertical distance along the Z-axis between the free end of the arm and tissue of the eye;
The control device is
- means for controlling said acquisition system to successively acquire a plurality of measurement pairs over time;
- means for processing each measurement pair, said processing means comprising:
- means for estimating the vertical distance along the Z-axis between the free end of the arm and the tissue of the eye from the current pair of measurements;
- From the image of the current measurement pair,
■ the current horizontal position of the free end of the arm in the horizontal plane XY;
(4) processing means, including means for calculating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY;
- a servo control means,
If the calculated horizontal displacement is greater than a first threshold, then move the arm horizontally in the horizontal plane XY to reduce the displacement between the current horizontal position and the desired final horizontal position. Create an instruction to move
between the free end of the arm and the tissue of the eye if the calculated horizontal displacement is less than a first threshold and the estimated vertical distance is greater than a second threshold; create an instruction to move the arm vertically along the vertical direction to reduce the distance of
Servo control to generate commands to lock the arm if the calculated horizontal displacement is less than a first threshold and if the measured vertical distance is less than a second threshold A control device, characterized in that it comprises means.

The present invention therefore allows the step of positioning the treatment device to be more accurate, repeatable and less costly than existing solutions.

Preferred but non-limiting aspects of the control device are as follows.
- said calculating means comprise:
- means for detecting the horizontal position of at least one point of interest of said eye tissue from the image of the current measurement pair;
- from the detected horizontal position of the point of interest,
■ the current horizontal position of the free end of the arm in the horizontal plane XY;
(2) means for evaluating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY;
- said detection means are capable of identifying tissue of said eye in acquired images by implementing a shape recognition algorithm for detecting three concentric circles in acquired images;
- the therapeutic device may further comprise a force sensor attached to the free end of the arm for measuring the mechanical force applied to the free end of the arm;
- the processing means combines the measured mechanical force with a third comprising means for comparing with a threshold of
- said servo control means are programmed to generate commands to immobilize said arm if said measured mechanical force is greater than a third threshold;
- said acquisition system, to acquire a signal representative of vertical distance along the Z-axis,
acquisition means by laser ranging, and/or acquisition means by ultrasound,
- It may include acquisition means by image processing,
- said servo control means may be programmed to generate element movement instructions enabling movement of said arm between a current position of said arm and a desired final position; creates a fixed instruction after each element move instruction.

The present invention also provides a method for controlling movement of an ophthalmic treatment device comprising:
The therapeutic device comprises:
- a support arm, the free end of which is intended to align with the tissue of the human or animal eye, the arm being bifurcated along three orthogonal axes X, Y and Z; each articulated to allow movement of the free end of the arm,
- the X-axis defines a horizontal longitudinal direction,
The Y axis defines the horizontal lateral direction, and together with the X axis defines the horizontal plane XY,
a support arm, the Z-axis of which defines a vertical direction and is perpendicular to the horizontal plane XY;
- an acquisition system mounted on said arm for acquisition of a measurement pair, said measurement pair comprising:
- an image of tissue of the eye;
an acquisition system comprising a signal representative of the vertical distance along the Z-axis between the free end of the arm and tissue of the eye;
The control method is
- successively acquiring multiple measurement pairs over time via said acquisition system;
- processing each measurement pair, the processing step comprising:
- approximating the vertical distance along the Z-axis between the free end of the arm and the tissue of the eye from the current pair of measurements;
- From the image of the current measurement pair,
■ the current horizontal position of the free end of the arm in the horizontal plane XY;
(2) calculating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY;
- servo-controlling the movement of said arm,
If the calculated horizontal displacement is greater than a first threshold, then move the arm horizontally in the horizontal plane XY to reduce the displacement between the current horizontal position and the desired final horizontal position. creating instructions to move
between the free end of the arm and the tissue of the eye if the calculated horizontal displacement is less than a first threshold and the estimated vertical distance is greater than a second threshold; creating an instruction to move the arm vertically along the vertical direction to reduce the distance of
Servo control by creating a command to lock the arm if the calculated horizontal displacement is less than a first threshold and if the measured vertical distance is less than a second threshold. A method, characterized in that it comprises the steps of:

Preferred but non-limiting aspects of the control method are as follows.
- said calculating step comprises:
- the sub-step of detecting the horizontal position of at least one point of interest of said eye tissue from the image of the current measurement pair;
- from the detected horizontal position of the point of interest,
■ the current horizontal position of the free end of the arm in the horizontal plane XY;
(2) evaluating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY;
- the detection sub-step may consist of identifying the tissue of the eye in the acquired image by implementing a shape recognition algorithm to detect three concentric circles in the acquired image;
- the therapeutic device may further comprise a force sensor attached to the free end of the arm for measuring the mechanical force applied to the free end of the arm;
- the processing step combines the measured mechanical force with a third and comparing with a threshold of
- the servo-control step comprises producing an instruction to lock the arm if the measured mechanical force is greater than a third threshold;
- said obtaining step comprises:
acquisition by laser ranging of signals representative of vertical distances along the Z-axis, and/or ultrasound acquisition of signals representative of vertical distances along the Z-axis, and/or vertical along the Z-axis. may include extraction of the acquired image from the signal representative of the distance;
- said servo control step comprises:
- creating element movement instructions that allow movement of the arm between its current position and a desired final position;
- creating a fixed instruction after each element move instruction;
• repeating the sub-steps until the calculated horizontal displacement is less than a first threshold and the measured vertical distance is less than a second threshold;

Other features and advantages of the invention will become clearly apparent from the following description of some alternative embodiments given as non-limiting examples from the accompanying drawings.

Figure 1 shows a treatment apparatus comprising a support arm and a control device according to the invention, said arm in Figure 1 in a retracted position. Figure 2 shows a treatment apparatus comprising a support arm and a control device according to the invention, said arm in Figure 2 in the deployed position. Figure 3 schematically shows a cutting system integrated into the treatment device. FIG. 4 schematically shows each step of the control method performed by the control device. FIG. 5 schematically illustrates the steps of moving the arm during a procedure for treating ocular lesions.

The present invention relates to devices and methods for controlling movement of therapeutic devices for human or animal ocular tissue. In the following description, the invention is described by way of example for cutting eye tissue, and it should be understood that the invention can be used for any other type of eye treatment.

Referring to FIG. 1, an example of a therapeutic device is shown.

The therapeutic device
- a movable box 1;
- an articulated support arm 2 attached to the box 1;
- a cutting system attached to arm 2;
- a force sensor 3 attached to the free end of the arm 2;
- an acquisition system 4 attached to the arm 2 for acquiring images and signals representative of the distance between the free end of the arm 2 and the tissue of the eye;
- comprising a control device 5 integrated in the box 1 and containing control means and processing means;

1. moveable box
Box 1 allows movement of the treatment equipment. The box 1 comprises, inter alia, wheels 11, a metal frame and suitable fairings such that there are minimal recesses to prevent dust or pathogenic elements from lodging and growing inside.

The box 1 is preferably provided with means of fixing with respect to the ground in order to prevent movement of the box 1 during surgical intervention.

The box 1 holds the various elements of the therapeutic equipment (eg the arm 2 and the control device 5) and comprises means for supplying them with electrical energy.

Box 1 further comprises a display input means 12 (e.g. a planning console) that allows the practitioner to control the treatment equipment and/or track the progress of the treatment applied to the patient's eye. good too.

Finally, the box 1 may comprise communication means 13, with or without wires for exchanging data with remote workstations (not shown), or built into the box 1. If not, the control device 5 is provided.

2. support arm
The arm 2 comprises several arm segments 21-24 connected by joints 25-27 (pivoting or ball-jointed connections), allowing movement when the different segments 21-24 rotate relative to each other. .

Each joint 25-27 has a power and a brake. Advantageously, each brake is of the active type in the absence of a supply of electrical energy. This makes it possible, for example, to prevent unpredictable movement of the arm in the event of system failure or power failure.

Arm joint power and brakes allow:
- automatic movement of arm segments 21-24 relative to box 1;

In particular, the arm is articulated to allow movement of the free end of the arm along three orthogonal axes X, Y and Z;
- the X-axis defines a horizontal longitudinal direction;
The Y-axis defines the horizontal lateral direction, and together with the X-axis defines the horizontal plane XY,
• The Z-axis defines the vertical direction and is perpendicular to the horizontal plane XY.

The free end of arm 2 comprises a fixation member provided with a suction ring capable of suctioning eye tissue and holding it firmly in place. The control devices and methods described below are capable of automatically positioning the fixation member relative to the ocular tissue to be treated.

As shown in FIGS. 1 and 2, the arm 2 is
- a retracted position (Fig. 1) that facilitates its transport from one intervention room to another and/or into an intervention room;
- It can be moved between an initial deployed position (Fig. 2) before positioning its free end against the tissue of the eye to be treated.

Arm 2 is, for example, TX260L marketed by STAUBLI.

Movement of the arm 2 is controlled by a control device 5,
- determine the current position in space of the free end of the arm at all times;
- the current position of the free end of the arm 2 by actuating one or more motors so as to reach the desired final position (where the fixation member is centered and in contact with the tissue of the eye); Create a move instruction to adjust the
- Create a command to lock the arm to hold it stationary by activating the brake.

Advantageously, the arm may be provided with declutching means to manually enable its movement, for example in the event of a defect or power failure.

3. cutting system
Referring to FIG. 3, one embodiment of a cutting system usable with a therapeutic device according to the present invention is shown. The cutting system
- a femtosecond laser 100;
- a shaping system 200, for example a liquid crystal spatial light modulator (or SLM), arranged downstream of the femtosecond laser 100;
- an optical coupler 300 between the femtosecond laser 100 and the shaping system 200;
- an optical scanner 400 downstream of the molding system 200;
- an optical focusing system 500 downstream of the optical scanner 400;

Control device 5 makes it possible to steer shaping system 200 , optical scanner 400 and optical focusing system 500 .

Femtosecond laser 100 has the ability to generate initial laser light in the form of pulses. "Femtosecond laser" means a light source capable of producing laser light in the form of very short pulses, the duration of which is from 1 femtosecond to 100 picoseconds, preferably from 1 to 1000 femtoseconds. , in particular on the order of about 100 femtoseconds.

Shaping system 200 extends across the optical path of initial laser light 110 emanating from femtosecond laser 100 . Shaping system 200 facilitates converting initial laser light 110 into modulated laser light 210 . More specifically, the shaping system modulates the phase of the laser light 110 and allows the energy of the laser light to be distributed to multiple impingement points in its focal plane, where the multiple impingement points are , which defines the pattern. In other words, the shaping system 200 allows the final energy distribution of the laser light to be modulated within the focal plane 710 corresponding to the cut plane of the tissue 700 . Shaping system 200 is adapted to alter the spatial profile of the wavefront of primary laser light 110 emerging from femtosecond laser 100 and distribute the energy of the laser light to different focal points within focal plane 710 . Thus, the shaping system 200 uses a phase mask from a normally distributed laser beam that produces a single impingement point to shape it by phase modulation (one beam upstream and one downstream of the SLM). Phase modulation makes it possible to distribute that energy so as to generate several impingement points in the focal plane simultaneously.

Optical coupler 300 allows transmission of laser light 110 from femtosecond laser 100 towards shaping system 200 . Optical coupler 300 advantageously comprises an optical fiber, in particular a hollow-core photonic crystal fiber (PCF). A hollow-core photonic crystal fiber is an optical fiber that guides light essentially inside the hollow region (the core of the fiber), so that only a small fraction of the light output is in the solid fiber material (typically propagates in glass). The attraction of hollow-core photonic crystal fibers is primarily that the predominant guiding within the hollow region minimizes the nonlinear effects of the modulated laser light, enabling high damage thresholds. Advantageously, the hollow region of the hollow-core photonic crystal fiber may be placed under vacuum to reduce propagation losses of laser light exiting femtosecond laser 100 . To this end, optical coupler 300 comprises first and second connection cells hermetically attached to each end of a hollow-core photonic crystal fiber. These connection cells are connected to a vacuum pump P incorporated in the casing 1, and by pumping with the connection cells the hollow cores of the optical fibers are placed under vacuum. The fact of vacuum pumping at each end of optical fiber 31 facilitates placing the hollow core under vacuum over the entire length of optical fiber 31 .

The optical scanner 400 deflects the modulated laser light 210 and allows the pattern to be moved within the focal plane 710 along a movement path predetermined by the user.

The optical focusing system 500 allows moving the focal plane 710 (corresponding to the cutting plane) of the deflected laser light 410 exiting the optical scanner 400 .

Advantageously, the shaping system 200, the optical scanner 400 and the optical focusing system 500 may be mounted in a compartment fixed to the distal end 24 of the arm, while the femtosecond laser may be incorporated in box 1. , an optical coupler 300 may extend between box 1 and terminal segment 24 to propagate initial laser light 110 between femtosecond laser 100 and shaping system 200 .

4. force sensor
A force sensor 3 makes it possible to detect the mechanical forces generated against movement of the arm 2, which reflect the presence of an obstacle (object), between the distal end of the arm 2 and the tissue of the eye. may correspond to obtaining contact between A force sensor 3 may be attached to the distal segment 24 of the arm 2 .

The force sensor 3 itself is of a type known to those skilled in the art. Force sensor 3 has the ability to capture and measure compressive and tensile forces applied along the longitudinal axis of distal segment 24 of arm 2 . Force sensor 3 comprises one (or more) strain gauges attached to distal segment 24 of arm 2 .

Each mechanical force measured by force sensor 3 is sent to control device 5 .

If the measured mechanical force value is greater than the threshold value, the control device performs one or more pre-determined tasks (creating commands to fix the arm, providing visual stimuli to the display input means 12). generation instructions and/or instructions to generate auditory stimuli to a loudspeaker built into the box, etc.).

5. Acquisition system
Acquisition system 4 makes it possible to acquire measurement pairs that are used to control the movement of arm 2 relative to the tissue of the eye to be treated.

Each measurement pair contains one (or more) images of the area located opposite the free end of arm 2 .

For this purpose, the acquisition system 4 may comprise an image acquisition unit of the OCT (optical coherence tomography) or Scheimpflug (visible light mapping) or UBM (ultrasound biomicroscope) type. Such an image acquisition unit may be attached to the distal segment 24 of arm 2 (eg, upstream of optical scanner 400). The image acquisition unit has a sufficiently large acquisition field (e.g., observes a perimeter P corresponding to a square with sides of 50 cm and a distance of 30 cm) so as to be able to identify the tissue of the eye in the acquisition field. ). Advantageously, the image acquisition unit may be provided with illumination means (coaxial or non-coaxial) to facilitate recognition of the ocular tissue.

Each measurement pair also contains one (or more) signals representative of the distance between the free end of the arm and the tissue of the eye.

For this purpose, the acquisition system 4 includes a laser ranging unit or an ultrasonic ranging unit or an image analysis ranging unit or a Ranging may be provided by any other equivalent device known to those skilled in the art capable of obtaining a signal representative of range. Such a ranging unit may also be attached to the distal segment 24 of arm 2 .

6. control device
The control device 5 is
- processing the measurement pairs originating from the acquisition system as well as the force measured by the force sensor 3; system 200, scanner 400, optical focusing system 500, vacuum pump of optical coupler 300, etc.), force sensor 3, acquisition system 4, etc.).

The control device 5 is connected to these various elements by one (or more) communication buses enabling the transmission of control signals and the reception of acquired data from the force sensors 3 of the acquisition system 4 . be.

The control device 5 may consist of one (or more) workstations and/or one (or more) computers. The control device 5 comprises a processor programmed to enable steering of the various elements of the therapy apparatus and processing of signals acquired by the force sensor 3 and acquisition system 4 .

The control device 5 is programmed to carry out the method shown in FIG. For this purpose, the control device 5
- means for controlling the acquisition system 4;
- means for processing each measurement pair acquired by the acquisition system 4;
- Servo control means for producing commands for moving and fixing the arm 2;

The control means enable the acquisition system 4 to acquire multiple measurement pairs in succession over time. More specifically, after each issuance of a fixing command by the servo control means, the control means issues an actuation signal from the acquisition system for the acquisition of a new measurement pair. This new measurement pair is processed by the processing means to update the deviation between the current position of the end of the arm and its desired final position.

The processing means is capable of detecting the three-dimensional position of the eye tissue and the three-dimensional position of the distal end of the arm from each acquired pair of measurements.

The three-dimensional position of the free ends of the arms is known by construction.

The three-dimensional position of the ocular tissue is obtained, in part, by calculation from the measurement pairs coming from the acquisition system 4 . For example, in the image acquired by the acquisition system 4, the processing means may consider the typical morphology of the eye (three concentric circles: a white circle (sclera), in the center of which there is a colored circle (iris), the By recognizing a shape that approximates a black circle in the center (pupil), the tissue of the eye, its two-dimensional position and its center can be identified. The third coordinates needed to approximate the three-dimensional position of the eye tissue are inferred from the signal acquired by the ranging unit, which signal measures the distance between the free end of the arm and the eye tissue. represent.

For processing each measurement pair received from the acquisition system 4, the processing means:
- means for estimating the vertical distance along the Z-axis between the end of the arm and the tissue of the eye from the current pair of measurements;
- from the image of the current measurement pair,
- the current horizontal position of the free end of the arm in the horizontal plane XY;
• Means for calculating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY.

The servo control means are programmed to implement a servo control loop in the horizontal plane XY and a servo control loop along the Z direction.

Advantageously, movement of the free end of arm 2 along the XY axes is uncorrelated with movement of arm 2 along the Z axis. In particular, the control device 5
- First, move the free end of the arm 2 in the horizontal plane XY to place it in the desired final horizontal position, preventing any movement of the free end along the vertical axis Z (i.e. the free end of the arm into the ocular tissue),
- Secondly, it is programmed to move the free end of the arm 2 along the vertical axis Z, and prevent any movement of the free end in the horizontal plane XY, to approach the eye tissue until contact is obtained.

This may result in injury to the patient (e.g., due to friction of the free end of the arm against the patient's eye if movement in the XY plane is commanded while the free end of the arm is already in contact with eye tissue). make it possible to avoid any risk of

Servo control means of control device 5 move the free ends of the arms from an initial deployed position to a desired final position in which the fixation member is centered and in contact with the tissue of the eye to be treated. has the ability to create multiple consecutive move orders for

More specifically, if the distance between the current position of the free end of the arm 2 and the desired final position is greater than a threshold, the servo control means bring the free end of the arm to the desired final position. Create multiple sequential element move instructions to go through.

During each mission of element movement commands, the servo control means produces a fixed command and the control means issues an actuation signal from the acquisition system 4 to acquire a new measurement pair. This allows for any unanticipated movement of the patient's head (in which case the desired final position has been updated) throughout the movement of the arm 2 so that the distal end of the arm is at the desired position. Allows verification of approaching final position.

7. Operating principle
The principle of operation of the therapeutic device will be explained in more detail with reference to FIGS. 4 and 5. FIG.

7.1. Before using the therapy device
It should be noted that, as a precondition for proper operation of the therapeutic equipment described above, wherever this equipment is used, the location of surgical equipment in the room must be defined by floor markings. deaf. This position is
- Surgeon's preference (right or left position, forward, side or back, near or far),
- the usual final position of the bed in which the patient lies,
- the shape of the bed, its dimensions, its height,
- the final position of the patient's head around the attachment point of the robotic arm of the surgical instrument, symbolizing the working range of the surgical instrument, or the distance beyond which the arm can no longer reach its target; It will be defined on the basis of respecting the distance constraint by ensuring that it is within the bounds to be centered.

Once the floor markings are defined, the therapy device will be placed in the same position for each use. In this way, the relative position of each patient with respect to the machine, in particular the relative position of the patient's head and eyes, is known to have an acceptable margin of error, which is 20 It can be up to centimeters.

Thus, with the parameterization accessible through the human-machine coordination of the apparatus, the head of each patient being prepared to undergo ocular treatment using the system of the present invention can be positioned. It would be possible to define the coordinates of the perimeter P (the perimeter P of a particular presence of the target) corresponding to a square with sides of 50 cm. Once the coordinates of this perimeter P are stored, on each use the control device 5 controls the positioning of the end of the arm in the middle of the perimeter P (by default and the number of repetitions required to obtain perfect centering). in front). This position corresponds to the initial deployed position.

Centering the fixation member and contacting the ocular tissue is accomplished as follows.

7.2. Automatic positioning of the free end of the arm relative to ocular tissue
7.2.1. arm deployment
Once the patient is lying down and the treatment apparatus is in place, control device 5 controls the deployment of arm 2 (step 801).

Arm 2 is automatically moved (as shown in the first four steps of FIG. 5) to place the free end of arm 2 in the middle of circumference P (initial deployed position).

Once the center of perimeter P is reached, a repeat of servo control loop XY is initiated.

7.2.2. XY servo control loop
The XY servo control loop, on each iteration,
- receive images,
- its analysis,
- identify the coordinates XY of the desired final horizontal position;
- determine the coordinates X', Y' of the current horizontal position of the free end of arm 2; and - calculate the deviation between the current horizontal position and the desired final horizontal position,
- calculating the remaining path between the current horizontal position and the desired final horizontal position;
- send one (or more) movement commands to arm 2 to move arm 2 along a path determined by computation, analysis of the received image confirms that the desired final horizontal position has been reached (X =X' and Y=Y'). The free ends of arms 2 are then aligned with the vertical axis through the middle of the eye tissue.
functions are programmed.

More specifically, the control means of control device 5 emit an activation signal from acquisition system 4 . Acquisition system 4 acquires an image and a signal representative of the distance between the end of the arm and the tissue of the eye.

The processing means receives and processes the measurement pairs acquired by acquisition system 4 (step 803).

In particular, the processing means
- detecting ocular tissue in the acquired image;
- determining the central position of the ocular tissue,
- defining the central position of this ocular tissue as corresponding to the desired final horizontal position,
- Estimate the current horizontal position of the free end of the arm; and - Compare the current horizontal position to the desired final horizontal position (step 804) (e.g., the current horizontal position to the desired final horizontal position). by calculating the distance between ).

sending the result of this comparison to the servo control means;
- if the current horizontal position matches the desired final horizontal position, control the execution of the Z servo control loop;
- Else, create an instruction to move arm 2 horizontally (step 805).

Once the arm 2 has moved according to the movement command, the servo control means generate a command to lock the arm 2 (step 806) until the free end of the arm 2 reaches the desired final horizontal position in XY. The previous steps (activating acquisition system 4, processing measurement pairs, etc.) are repeated.

7.2.3. Z servo control loop
Once the free end of arm 2 is aligned with the desired final horizontal position in XY, the Z servo control loop may be executed.

The Z-servo control loop, on each iteration,
- receive the current height data from the end of arm 2 relative to the tissue of the eye (current position Z'-desired position Z);
- calculating the deviation between the current vertical position of the end of the arm and the desired final vertical position;
- calculating the remaining path between the current vertical position and the desired final vertical position;
sending one (or more) movement commands to the arm 2 to move the arm 2 relative to the axis Z along the path determined by the calculation without changing the position XY, the force sensor 3 We do this until we find a touch (Z'=Z) that reflects the fact that we have reached the desired final vertical position. the free end of arm 2 then contacts the tissue of the eye;
functions are programmed.

More specifically, the processing means of the control device 5 processes the signal representing the vertical distance along the axis Z (step 803) and compares the current vertical position with the desired final vertical position (step 807).

The result of this comparison is sent to the servo control means, which also receive the signal measured by the force sensor 3 . The servo control means are
- if the current vertical position matches the desired final vertical position, create an instruction to lock arm 2 (step 810);
- Else, create a command to move arm 2 vertically (step 808).

Once the arm 2 has moved according to the vertical movement command, the servo control means generates a command to lock the arm 2 (step 809) and checks whether the current horizontal position always corresponds to the desired final horizontal position. To do so, the previous steps are repeated, including those of the XY servo control loop.

This makes it possible to consider possible movements of the patient during the arm 2 positioning procedure.

A control device 5 allows the positioning of the free ends of the arms in a precise and centered manner. This free end carries various working components that allow treatment of the tissue of the eye.

In a manner that is useful and anxiety-relieving to the practitioner, the sequence of various steps shown in FIG. Can be controlled by mechanical harmony.

8. Conclusion
The invention described above enables automatic positioning of an ocular fixation member in a patient's eye in a matter of seconds and without human intervention in a rapid, accurate and repeatable manner. Its performance depends on the environment and the be independent.

The present invention also provides additional safety, thus allowing the risk posed by the patient during the intervention to be reduced.

The reader will appreciate that many modifications may be made to the invention as described without departing physically from the new teachings and advantages described herein. For example, in the description above, the fixed member was attached to the free end of the robot arm. Alternatively, the stationary member may be separate from the robot arm. In this case, the fixation member is placed on the patient's eye prior to movement of the robotic arm, and the desired final position is opposite the free end of the robot arm and the surface of the fixation member that is in contact with the eye. contact with the other side of the fixed member. As a result, all such modifications are intended to be included within the scope of the invention as set forth in the appended claims.

Claims (12)

A device (5) for controlling movement of an ocular treatment device, comprising:
The therapeutic device comprises:
- a support arm (2), the free end of said arm (2) intended to align with the tissue of the human or animal eye, said arm (2) extending along three orthogonal axes X , Y and Z two each, articulated to allow movement of the free ends of said arms (2),
- the X-axis defines a longitudinal direction extending horizontally;
the Y-axis defines a lateral direction extending horizontally, the Y-axis and the X-axis define a horizontal plane XY,
a support arm (2), the Z-axis of which defines a vertical direction and is perpendicular to the horizontal plane XY;
- an acquisition system (4) mounted on said arm (2) for acquisition of a measurement pair, said measurement pair comprising:
- an image of tissue of the eye;
an acquisition system (4) comprising a signal representative of the vertical distance along the Z-axis between the free end of the arm (2) and the tissue of the eye;
Said control device (5) comprises:
- means for controlling said acquisition system (4) to successively acquire a plurality of measurement pairs over time;
- means for processing each measurement pair, said processing means comprising:
- means for estimating the vertical distance along the Z-axis between the free end of the arm and the tissue of the eye from the current pair of measurements;
- From the image of the current measurement pair,
■ the current horizontal position of the free end of the arm in the horizontal plane XY;
(4) processing means, including means for calculating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY;
- a servo control means,
- if the calculated horizontal deviation is greater than a first threshold, move the arm (2) in the horizontal plane XY to reduce the deviation between the current horizontal position and the desired final horizontal position; Create an instruction to move horizontally,
between the free end of the arm and the tissue of the eye if the calculated horizontal displacement is less than a first threshold and if the estimated vertical distance is greater than a second threshold; create a command to move said arm (2) vertically along the vertical direction to reduce the distance of
Servo control to generate commands to lock the arm if the calculated horizontal displacement is less than a first threshold and if the measured vertical distance is less than a second threshold A control device, characterized in that it comprises means. The calculation means is
- means for detecting the horizontal position of at least one point of interest of said eye tissue from the image of the current measurement pair;
- from said horizontal position of said detected point of interest,
- the current horizontal position of the free end of the arm in the horizontal plane XY;
- means for evaluating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY. 3. The method of claim 2, wherein the detection means is capable of identifying tissue of the eye in an acquired image by implementing a shape recognition algorithm for detecting three concentric circles in the acquired image. control device. The treatment device further comprises a force sensor (3) attached to the free end of the arm for measuring the mechanical force applied to the free end of the arm;
- said processing means combine said measured mechanical force with a third comprising means for comparing with a threshold of
- according to any one of claims 1 to 3, wherein the servo control means are programmed to generate commands to immobilize the arm if the measured mechanical force is greater than a third threshold; Control device as described. For the acquisition system to acquire a signal representative of vertical distance along the Z-axis,
- acquisition means by laser ranging, and/or - acquisition means by ultrasound,
- a control device according to any one of claims 1 to 4, comprising acquisition means by image processing. said servo control means being programmed to produce element movement instructions enabling movement of said arm between a current position of said arm and a desired final position; 6. A control device according to any one of claims 1 to 5, which creates a fixed instruction after the element movement instruction of . A method of operating a device for controlling movement of an ophthalmic treatment device comprising:
The therapeutic device comprises:
- a support arm (2), the free end of said arm (2) intended to align with the tissue of the human or animal eye, said arm (2) extending along three orthogonal axes X , Y and Z two each, articulated to allow movement of the free ends of said arms (2),
- the X-axis defines a horizontal longitudinal direction,
the Y-axis defines the horizontal lateral direction, the Y-axis and the X-axis define the horizontal plane XY,
a support arm (2), the Z-axis of which defines a vertical direction and is perpendicular to the horizontal plane XY;
- an acquisition system (4) mounted on said arm (2) for acquisition of a measurement pair, said measurement pair comprising:
- an image of tissue of the eye;
- an acquisition system (4) comprising a signal representative of the vertical distance along the Z-axis between the free end of the arm and the tissue of the eye;
The method of operation comprises:
- said controller acquires (802) a plurality of pairs of measurements sequentially over time via said acquisition system;
- said controller processing (803) each measurement pair, said processing step comprising:
- the controller approximating the vertical distance along the Z-axis between the free end of the arm and the tissue of the eye from the current pair of measurements;
- said control unit, from the image of the current measurement pair,
■ the current horizontal position of the free end of the arm in the horizontal plane XY;
(2) calculating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY;
- said controller servo-controlling the movement of said arm (2),
- if the calculated horizontal deviation is greater than a first threshold, the controller may cause the horizontal plane XY to reduce the deviation between the current horizontal position and the desired final horizontal position. creating (805) an instruction to move the arm (2) horizontally;
- if the calculated horizontal displacement is less than a first threshold and if the estimated vertical distance is greater than a second threshold, then the control device will move the free end of the arm to the eye. generating (808) instructions to move the arm (2) vertically along the vertical direction to reduce the distance between the tissue of
- if the calculated horizontal displacement is less than the first threshold and if the measured vertical distance is less than the second threshold, the controller issues a command to immobilize the arm; Creating (810)
and servo- controlling with. The calculation step includes:
- the sub-step of detecting the horizontal position of at least one point of interest of said eye tissue from the image of the current measurement pair;
- from the detected horizontal position of said point of interest,
- the current horizontal position of the free end of the arm in the horizontal plane XY;
8. A method of operation according to claim 7, comprising the sub-step of evaluating the horizontal deviation between the desired final horizontal position of the free end of the arm in the horizontal plane XY. 9. The operation of claim 8, wherein the detecting substep comprises identifying the eye tissue in the acquired image by implementing a shape recognition algorithm to detect three concentric circles in the acquired image. Method. said treatment device further comprising a force sensor (3) attached to the free end of said arm (2) for measuring the mechanical force applied to said free end of said arm (2);
- the processing step determines whether the free end of the arm is in contact with an element that interferes with the vertical movement of the arm along the Z-axis; and comparing with a threshold of
- the method of actuation according to any one of claims 7 to 9, wherein said servo-control step comprises generating an instruction to lock said arm if said measured mechanical force is greater than said third threshold value; . The obtaining step comprises:
- Acquisition by laser ranging of signals representative of vertical distances along the Z-axis, and/or - Acquisition of signals representative of vertical distances along the Z-axis by ultrasound, and/or - Vertical along the Z-axis. A method of operation according to any one of claims 7 to 10, comprising extracting the acquired image from a signal representative of the distance. The servo control step includes
- creating element movement instructions that allow movement of the arm between its current position and a desired final position;
- creating a fixed command after each element move command,
- repeating said sub-steps until said calculated horizontal displacement is less than a first threshold and said measured vertical distance is less than a second threshold; The operating method according to item 1.