RU2775140C2 - Device and method for control of movement of eye therapy device - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to devices for control of the movement of an eye therapy device. The eye therapy device contains a hinged manipulator and a data collection system mounted on the manipulator. The free end of the manipulator is designed to be placed opposite human or animal eye tissue. The data collection system is designed to obtain a pair of measurements, including: an image of eye tissue and a signal characterizing the vertical distance between the end of the manipulator and eye tissue. The control device contains: means for control of the data collection system to obtain pairs of measurements sequentially in time; means for processing of each pair of measurements; automatic control means for movement of the free end of the manipulator between an initial position and a certain final position.

EFFECT: possibility of automatization of an installation phase of an eyeball immobilization element in place.

12 cl, 5 dwg

Description

Technical field

The present invention relates to the general technical field of the treatment of ocular pathologies using therapeutic equipment intended for performing eye surgeries and in particular:

- operations on the anterior segment of the eye, for example, in the case of cataracts (on the lens) and/or

- refractive surgery (on the cornea) and/or

- operations intended for the treatment of glaucoma or other retinal pathologies.

More specifically, the invention relates to a device and method for controlling the movement of an ocular pathology treatment system mounted on an articulated robotic arm to ensure its movement along three orthogonal axes X, Y and Z.

In general, the present invention finds its application when therapeutic equipment is to be operated in the eye at the surface or in depth by physical means (such as light waves, ultrasound, microwaves, etc.) whose trajectory must be accurately controlled in order to reach the target, without damaging adjacent structures.

In the following, the invention will be described with reference to therapeutic equipment, including an articulated robotic arm equipped with a system for cutting human or animal tissue, such as the cornea or lens, using a femtosecond laser.

However, one of skill in the art will appreciate that the invention described below can be used to control movement of an articulated robotic arm comprising any other type of ocular pathology treatment system.

State of the art

There are many types of therapeutic equipment containing a laser for the treatment of ocular pathology. In this case, the laser is used as an optical scalpel.

Such a laser can cut the transparent tissues of the eye in depth without the use of surgical instruments. Its advantage is speed and good tolerance, and especially the ability to dispense with the manual surgical gesture, which is an operator-dependent factor.

Thus, laser-assisted surgery becomes extremely precise and repeatable. It provides a guarantee of safety that cannot be achieved with a gesture performed by a human operator, so the use of a laser allows for almost automated surgery, in which the machine performs the steps of the surgical operation instead of the doctor.

In order for the therapeutic equipment containing the laser to be able to carry out the stages of the treatment procedure, two main phases must first be carried out:

i) fix the therapy equipment on the eye to prevent eye movements during the treatment procedure and to align the axis of the eye with the coordinate system of the machine; in this way, the machine and the eye are aligned and firmly connected, and treatment can be started in complete safety, without fear of displacement or movement during the procedure,

ii) create a mapping of the intraocular structures of the patient using an integrated imaging system such as OCT (optical coherence tomography) or Scheimpflug (visible light mapping) or UBM (ultrasonic biomicroscopy) imaging technology to outline the areas to be treated with a laser beam to cut or fragment them.

In order to carry out step i), it is necessary to position an immobilization element on the patient's eye, equipped with a suction ring, which is sucked to the eye and holds it securely in place.

Currently, therapeutic equipment operating in the eye and requiring immobilization of the eyeball during phases i) and ii) (then during the treatment phase) is equipped with an immobilization element that is manipulated manually by the operator.

Such therapeutic equipment has a number of disadvantages:

- manual positioning of the immobilization element is subject to some variability, which depends on many factors; in particular, the quality of the positioning of the immobilization element varies from one operator to another; this leads to variability in the conditions of immobilization of patients, while it should be borne in mind that the quality of treatment largely depends on the quality of positioning of the immobilization element;

- the time required for the positioning of the immobilization element by the operator (such as a surgeon) is very valuable and therefore very expensive compared to an action that could be entrusted to a machine that can perform it very accurately, in a repeatable manner and at a much lower cost ,

- manipulation of the immobilization element is often laborious, since the operator is not in optimal conditions and often encounters various obstacles when observing the eyeball, which do not allow him to determine whether the positioning of the immobilization element is correct or not,

- the ability of the operator to judge the normal positioning of the eye immobilization element, which should be based on indicators that require points of reference in space (centering level, the presence of tilt, rotation, etc.), is much lower than that of a machine that is equipped with sensors and imaging systems capable of correcting errors in X, Y, or Z position or position in space at exceptionally precise levels of resolution,

- Depending on the skill of the operator, patients may experience discomfort, cut or poor positioning of the immobilization element, which may affect the effectiveness of the treatment.

The present invention aims to provide an intelligent and autonomous system using robotic movements, imaging tools, sensors, and image interpretation capabilities from an embedded data acquisition system to automate the insertion phase of an eyeball immobilizer.

Disclosure of invention

For this purpose, the object of the invention is a device for controlling the movement of an ophthalmic therapy device, comprising:

- a manipulator, while the free end of the manipulator is designed to be placed against human or animal eye tissue, the specified manipulator is articulated to ensure movement of the free end of the manipulator along three pairwise orthogonal axes X, Y and Z:

- along the X axis, which defines the horizontal longitudinal direction,

- along the Y-axis, which defines the horizontal transverse direction, which together with the X-axis forms the horizontal XY plane,

- along the Z axis, which defines the vertical direction, perpendicular to the horizontal XY plane,

- a data acquisition system installed on the manipulator and designed to obtain a pair of measurements, including:

- an image of the eye tissue, and

- signal characterizing the vertical distance along the Z axis between the end of the manipulator and the eye tissue,

characterized in that the control device contains:

- means of controlling the data acquisition system for obtaining multiple pairs of measurements sequentially in time,

- means of processing each pair of measurements, while said means of processing include:

- means of estimating, based on the current pair of measurements, the vertical distance along the Z axis between the end of the manipulator and the ocular tissue,

- means of calculating, based on the image of the current pair of measurements, the horizontal deviation between:

- the current horizontal position of the free end of the manipulator in the horizontal XY plane, and

- a certain final horizontal position of the free end of the manipulator in the horizontal XY plane,

- means of automatic control, made with the possibility of:

- if the calculated horizontal deviation exceeds the first threshold value, generate a control signal for horizontal movement of the manipulator in the horizontal XY plane in order to reduce the deviation between the current horizontal position and the specified defined final horizontal position,

- if the calculated horizontal deviation is less than the first threshold value and if the estimated vertical distance exceeds the second threshold value, generate a control signal to move the manipulator vertically in the vertical direction to reduce the distance between the free end of the manipulator and the ocular tissue,

- if the calculated horizontal deviation is less than the first threshold value and if the measured vertical distance is less than the second threshold value, generate a manipulator immobilization control signal.

Thus, the invention makes it possible to make the installation phase of therapeutic equipment more accurate, repeatable and cheaper than existing solutions.

The control device has the following preferred but non-limiting features:

- calculation tools may contain:

- means for detecting, based on the image from the current pair of measurements, the horizontal position of at least one point of interest in the eye tissue,

- a means of estimating, based on the detected horizontal position of the point of interest, the horizontal deviation between:

- the current horizontal position of the free end of the manipulator in the horizontal XY plane, and

- a certain final horizontal position of the free end of the manipulator in the horizontal XY plane;

the detection means can be configured to identify the ocular tissue in the acquired image by applying a shape recognition algorithm to detect three concentric circles in the image;

the therapeutic device may further comprise a force sensor mounted on the free end of the manipulator to measure the mechanical force applied to the free end of the manipulator;

wherein the processing means comprise means for comparing said measured mechanical force with a third threshold value in order to determine whether the free end of the manipulator comes into contact with an element that forms an obstacle to the vertical movement of the manipulator along the Z axis,

- at the same time, the automatic control means are programmed in such a way as to generate a control signal for the immobilization of the manipulator if the measured mechanical force exceeds the third threshold value;

- to obtain a signal characterizing the vertical distance along the Z axis, the data acquisition system may contain:

- means for obtaining data by means of laser telemetry, and/or

- means for obtaining data using ultrasounds,

- means for obtaining data by means of image processing;

- automatic control means can be programmed in such a way as to generate control signals to ensure the movement of the manipulator between its current position and a certain end position, while said automatic control means generate an immobilization control signal after each elementary movement control signal.

The object of the invention is also a method for controlling the movement of an ophthalmic therapy device comprising:

- a manipulator, while the free end of the manipulator is designed to be placed against human or animal eye tissue, while the specified manipulator is articulated to ensure movement of the free end of the manipulator along three pairwise orthogonal axes X, Y and Z:

- along the X axis, which defines the horizontal longitudinal direction,

- along the Y-axis, which defines the horizontal transverse direction, which together with the X-axis forms the horizontal XY plane,

- along the Z axis, which defines the vertical direction, perpendicular to the horizontal XY plane,

- a data acquisition system installed on the manipulator and designed to obtain a pair of measurements, including:

- an image of the eye tissue, and

- signal characterizing the vertical distance along the Z axis between the end of the manipulator and the eye tissue,

characterized in that the control method comprises the following phases:

- reading a plurality of pairs of measurements sequentially in time using a data acquisition system,

- processing each pair of measurements, while the processing phase contains the following steps:

- based on the current pair of measurements, the vertical distance along the Z axis between the end of the manipulator and the ocular tissue is estimated,

- based on the image from the current pair of measurements, calculate the horizontal deviation between:

- the current horizontal position of the free end of the manipulator in the horizontal XY plane, and

- a certain final horizontal position of the free end of the manipulator in the horizontal XY plane,

- perform automatic regulation of the movement of the manipulator, while:

- if the calculated horizontal deviation exceeds the first threshold value, generating a control signal for horizontal movement of the manipulator in the horizontal XY plane in order to reduce the deviation between the current horizontal position and the determined final horizontal position,

- if the calculated horizontal deviation is less than the first threshold value and if the estimated vertical distance exceeds the second threshold value, generating a control signal to vertically move the manipulator in the vertical direction to reduce the distance between the free end of the manipulator and the ocular tissue,

- if the calculated horizontal deviation is less than the first threshold value and if the measured vertical distance is less than the second threshold value, the manipulator immobilization control signal is generated.

The control method has the following preferred, but non-limiting features:

- the calculation stage may contain the following sub-stages:

- based on the image from the current pair of measurements, the horizontal position of at least one point of interest in the eye tissue is detected,

- based on the detected horizontal position of the point of interest, estimate the horizontal deviation between:

- the current horizontal position of the free end of the manipulator in the horizontal XY plane, and

- a certain final horizontal position of the free end of the manipulator in the horizontal XY plane;

- in the detection sub-step, it is possible to identify the ocular tissue in the acquired image by applying a shape recognition algorithm to detect three concentric circles in the image;

the therapeutic device may further comprise a force sensor mounted on the free end of the manipulator to measure the mechanical force applied to the free end of the manipulator;

wherein the processing phase comprises the step of comparing said measured mechanical force with a third threshold value in order to determine whether the free end of the manipulator comes into contact with an element that forms an obstacle to the vertical movement of the manipulator along the Z axis,

the automatic control step includes generating an immobilization control signal if the measured mechanical force exceeds a third threshold value;

- the data acquisition phase may contain:

- acquisition by means of laser telemetry of a signal characterizing the vertical distance along the Z-axis, and/or

- obtaining by means of ultrasound a signal characterizing the vertical distance along the Z-axis, and/or

- selection in the received image of a signal characterizing the vertical distance along the Z axis;

- the stage of automatic regulation may include:

- generating a control signal of an elementary movement to ensure the movement of the manipulator between its current position and a certain end position,

- generating an immobilization control signal following each elementary displacement control signal,

- repeating the previous sub-steps until the calculated horizontal deviation is less than the first threshold value and until the measured vertical distance is less than the second threshold value.

Brief description of the drawings

Other features and advantages of the invention will become more apparent from the following description of several embodiments, given by way of non-limiting examples, with reference to the accompanying drawings, in which:

Fig. 1 and 2 - a therapeutic device, including a manipulator and the claimed control device, while the manipulator is shown:

- in the retracted position in FIG. 1, and

- in the expanded position in FIG. 2.

Fig. 3 is a schematic view of a cutting system incorporated in a therapy device.

Fig. 4 is a diagram of the steps of the control method carried out in the control device.

Fig. 5 - stages of movement of the manipulator during the procedure for the treatment of ocular pathology.

Detailed description of the invention

The invention relates to a device and method for controlling the movement of a therapeutic device for treating human or animal eye tissue. In the following text of the description, the invention will be presented, as an example, for cutting ocular tissue, while, of course, the present invention can be applied to any other type of eye treatment.

In FIG. 1 shows an example of a therapeutic apparatus.

The therapy device contains:

- movable body 1,

- articulated manipulator 2 mounted on the body 1,

- cutting system installed on the manipulator 2,

- force sensor 3 installed at the free end of the manipulator 2,

- a data acquisition system 4 installed on the manipulator 2 and designed to obtain images and signals characterizing the distance between the free end of the manipulator 2 and the eye tissue,

a control device 5 built into the housing 1, the control device 5 including control means and processing means.

1. Movable body

Housing 1 provides movement of therapeutic equipment. In particular, it contains wheels 11, a metal frame and a casing made with a minimum number of blind cavities in order to avoid the accumulation of dust in them and the propagation of pathogenic elements.

Preferably, the body 1 contains means of immobilization relative to the floor to prevent its movement during surgery.

On the body 1, various elements of therapeutic equipment, such as a manipulator 2 and a control device 5, are mounted, and it contains means for supplying them with electrical energy.

In addition, the housing 1 may contain means 12 of visual indication and input, such as an operating console, allowing the physician to operate the therapeutic equipment and/or monitor the progress of treatment being applied to the patient's eye.

Finally, the housing 1 may contain wired or wireless communication means 13 for communicating with a remote work station (not shown) or with a control device 5 if it is not built into the housing.

2. Manipulator

Manipulator 2 contains several sections 21-24 of the manipulator, connected by hinges 25-27 (swivel or ball) to ensure rotary movement of various sections 21-24 relative to each other.

Each hinge 25-27 contains a mechanized drive and a brake. Preferably, each brake is of the active type in case of power failure. This prevents any accidental movement of the manipulator in the event of a system failure or a power outage.

Mechanized drives and brakes of the manipulator joints provide:

- automatic movement of sections 21-24 of the manipulator relative to the body 1, and

- immobilization of sections 21-24 of the manipulator relative to the body 1.

In particular, the manipulator is articulated to ensure movement of the free end of the manipulator along three orthogonal axes X, Y and Z:

- along the X axis, which defines the horizontal longitudinal direction,

- along the Y-axis, which defines the horizontal transverse direction, which together with the X-axis forms the horizontal XY plane,

- along the Z axis, which defines the vertical direction perpendicular to the horizontal XY plane.

The free end of the manipulator 2 contains an immobilization element equipped with a suction ring, which is sucked to the ocular tissue and holds it securely in place. The control device and method described below make it possible to automatically position the immobilization element on the eye tissue intended for treatment.

As shown in FIG. 1 and 2, the manipulator 2 is movable between:

- retracted position (Fig. 1), facilitating its transportation from one operating room to another and/or within one operating room, and

- the initial deployed position (Fig. 2) before positioning its free end on the treated eye tissue.

The manipulator 2 is, for example, a TX260L manipulator manufactured by STAUBLI.

The movement of the manipulator 2 is controlled by a control device 5 which:

- determines at each moment the current position in space of the free end of the manipulator,

- generates movement commands in order to correct the current position of its free end by activating one or more actuators to reach a certain end position in which the immobilization element is centered and comes into contact with the eye tissue,

- generates manipulator immobilization commands to keep the manipulator stationary by activating the brakes.

Preferably, the manipulator may include shutdown means to enable it to be manually moved, for example in the event of a failure or power outage.

3. Cutting system

In FIG. 3 shows an embodiment of a cutting system that can be used with a therapy device according to the invention. The cutting system contains:

- femtosecond laser 100,

a shaping system 200, such as a liquid crystal spatial light modulator (or SLM for “Spatial Light Modulator”) located at the output of the femtosecond laser 100,

- an optical connector 300 between the femtosecond laser 100 and the shaping system 200,

- an optical scanner 400 at the exit of the shaping system 200,

- optical system 500 focusing at the output of the optical scanner 400.

The control device 5 makes it possible to control the shaping system 200, the optical scanner 400 and the focusing optical system 500.

The femtosecond laser 100 is configured to emit the initial laser beam in the form of pulses. By "femtosecond laser" is meant a light source capable of emitting a laser beam in the form of ultrashort pulses, the duration of which is from 1 femtosecond to 100 picoseconds, preferably from 1 to 1000 femtoseconds, in particular on the order of hundreds of femtoseconds.

The shaping system 200 is located on the path of the original laser beam 110 exiting the femtosecond laser 100. It allows the original laser beam 100 to be transformed into a modulated laser beam 210. In particular, the shaping system allows the phase of the laser beam 110 to be modulated to distribute the energy of the laser beam over a plurality of irradiation points in its focal plane, and this set of irradiation points forms a pattern. In other words, the shaping system 200 modulates the final energy distribution of the laser beam in the focusing plane 710 corresponding to the cutting plane of the tissue 700. It is configured to change the spatial wavefront profile of the primary laser beam 110 emerging from the femtosecond laser 100 in order to distribute the energy of the laser beam to different focus points in the focus plane 710. Thus, starting from a Gaussian laser beam that creates a single point of illumination, using a phase mask, the shaping system 200 allows the beam energy to be distributed by phase modulation to simultaneously create several points of illumination in the focusing plane, using a single laser beam formed by phase modulation (only one beam at the input and output of the SLM modulator).

The optical connector 300 allows the laser beam 110 output from the femtosecond laser 100 to be transmitted to the shaping system 200 . Preferably it contains an optical fiber, in particular a photonic crystal fiber (or "PCF" short for the Anglo-Saxon expression "Photonic-Crystal Fiber") with a hollow core. A hollow core photonic crystal fiber is an optical fiber that guides light primarily within a hollow region (fiber core) so that only a minimal portion of the optical power propagates in the solid fiber material (typically glass). The main advantage of hollow-core photonic crystal fibers is that the primary guidance in the hollow region minimizes the non-linear effects of the modulated laser beam and provides a high damage threshold. Preferably, a vacuum can be created in the hollow region of the hollow-core photonic crystal fiber to limit the propagation loss of the laser beam exiting the femtosecond laser 100. To do this, the optical connector 300 includes first and second connectors hermetically mounted at each end of the photonic crystal fiber with hollow core. These connectors are connected to a vacuum pump P built into the housing 1 to create a vacuum in the hollow core of the optical fiber by pumping at the level of the connectors. Vacuum pumping at each end of the optical fiber 31 facilitates the creation of a vacuum in the hollow core along the entire length of the optical fiber 31.

The optical scanner 400 allows the modulated laser beam 210 to be oriented so that the user can move the pattern along a predetermined movement path in the focus plane 710.

The focus optical system 500 allows the focus plane 710 corresponding to the cutting plane of the deflected laser beam 410 exiting the optical scanner 400 to be moved.

Preferably, the shaping system 200, the optical scanner 400, and the focusing system 500 can be installed in a compartment fixed at the end 24 of the manipulator, while the femtosecond laser can be built into the housing 1, with an optical connector 300 located between the housing 1 and the end section 24 for transferring the original laser beam 110 between the femtosecond laser 100 and the shaping system 200.

4. Force sensor

The force sensor 3 detects mechanical forces that oppose the movement of the manipulator 2, and these forces are indicative of the presence of an obstacle and may correspond to the establishment of contact between the end of the manipulator 2 and the ocular tissue. The force sensor 3 can be installed on the end section 24 of the manipulator 2.

The force sensor 3 is known per se to the person skilled in the art. It is configured to detect and measure the compressive and tensile forces acting along the longitudinal axis of the end section 24 of the manipulator 2. It contains one or more strain gauges mounted on the end section 24 of the manipulator 2.

The value of each mechanical force measured by the force sensor 3 is transmitted to the control device 5 .

If the value of the measured mechanical force exceeds the threshold value, the control device performs one or more predetermined actions (generating a control signal to immobilize the manipulator, commands to transmit a visual signal to the visual indication and input means 12 and / or an audio signal to the speaker built into the housing, and etc.).

5. Data acquisition system

The data acquisition system 4 makes it possible to obtain pairs of measurements used to control the movement of the manipulator 2 in relation to the treated ocular tissue.

Each pair of measurements includes one or more images of the area opposite the free end of the manipulator 2.

To this end, the acquisition system 4 may comprise an imaging unit of the OCT (optical coherence tomography) type or Scheimpflug (visible light mapping) or UBM (ultrasonic biomicroscopy) imaging technologies. Such an image pickup unit can be installed at the end section 24 of the arm 2, for example, at the entrance of the optical scanner 400. This image pickup unit is positioned in such a way as to have a sufficiently wide field of view (for example, to observe the perimeter P corresponding to a square with a side of 50 cm on distance of 30 cm) and provide identification of the eye tissue in the field of view. Preferably, the image pickup unit may be provided with lighting means (coaxial or not) to facilitate recognition of ocular tissue.

Each pair of measurements also contains one or more signals characterizing the distance between the free end of the manipulator 2 and the eye tissue.

To do this, the data acquisition system 4 may include a laser telemetry unit or an ultrasonic telemetry unit, or a telemetry unit by image analysis, or any other equivalent device known to a person skilled in the art and configured to read a signal characterizing the distance between the free end of the manipulator 2 and the object. opposite this end. Such a telemetry unit can also be installed on the end section 24 of the manipulator 2.

6. Control device

The control device 5 allows:

- to process pairs of measurements coming from the data acquisition system, as well as the forces measured by the force sensor 3, and

- control various elements that make up the therapeutic apparatus (manipulator 2, cutting system (in particular, femtosecond laser 100, shaping system 200, scanner 400, optical focusing system 500, optical connector vacuum pump 300, etc.), sensor 3 forces, 4 data acquisition system, etc.).

The control device 5 is connected to these various elements via one or more communication buses providing control signals and receiving collected data from the force sensor 3, from the data collection system 4, etc.

The control device 5 may consist of one or more work stations and/or one or more computers. The control device 5 includes a processor programmed to provide control of various elements of the therapeutic device in order to process the signals received by the force sensor 3 and the data acquisition system 4 .

The control device 5 is programmed to carry out the method shown in FIG. 4. To this end, the control device 5 comprises:

- control means of the data collection system 4,

means for processing each pair of measurements received by the data acquisition system 4, and

- automatic control means for generating control signals for moving and immobilizing the manipulator 2.

The controls make it possible to activate the data collection system 4 to obtain a plurality of pairs of measurements sequentially in time. In particular, after each transmission of the immobilization control signal by the automatic control means, the control means issue an activation signal from the data acquisition system to obtain a new pair of measurements. The processing means processes this new pair of measurements to update the deviation between the current end position of the manipulator and its defined end position.

Based on each pair of measurements, the processing means can detect the three-dimensional position of the ocular tissue and the three-dimensional position of the end of the manipulator.

The three-dimensional position of the free end of the manipulator is known from the design.

The three-dimensional position of the ocular tissue is determined by calculation based on a pair of measurements coming from the data acquisition system 4 . For example, in the image obtained by the data acquisition system 4, the processing means can identify the eye tissue, its two-dimensional position and its center, recognizing a shape close to the typical morphology of the eye (three concentric circles: a white circle (sclera), in the center of which is a colored circle (iris), in the center of which is a black circle (pupil)). The third coordinate necessary for estimating the three-dimensional position of the ocular tissue is derived from the signal read by the telemetry unit, and this signal characterizes the distance between the free end of the manipulator and the ocular tissue.

For processing each pair of measurements received from the data collection system 4, the processing means include:

- means of estimating, based on the current pair of measurements, the vertical distance along the Z axis between the end of the manipulator and the ocular tissue,

- means of calculating, based on the image of the current pair of measurements, the horizontal deviation between:

- the current horizontal position of the free end of the manipulator in the horizontal XY plane, and

- a certain final horizontal position of the free end of the manipulator in the horizontal XY plane.

The controls are programmed to use the control loop in the XY plane and the control loop in the Z direction.

Preferably, the movement of the free end of the manipulator 2 along the XY axes is not associated with its movement along the Z axis. In particular, the control device is programmed in such a way that:

- in the first step, move the free end of the manipulator 2 in the horizontal XY plane to position said free end to a certain final horizontal position, without allowing any movement of the free end along the Z axis (that is, without bringing the free end of the manipulator closer to the ocular tissue),

- at the second stage, move the free end of the manipulator 2 along the vertical Z axis to bring it closer to the eye tissue until contact is established, while preventing any movement of the free end in the horizontal XY plane.

This avoids any risk of injury to the patient (for example, friction between the free end of the manipulator and the patient's eye if movement is set in the XY plane, when the end is already in contact with ocular tissue).

The means of automatic adjustment of the control device 5 are configured to generate a plurality of successive movement control signals in order to move the free end of the manipulator from the initial deployed position to a certain final position, in which the immobilization element is centered and comes into contact with the ocular tissue intended for treatment.

In particular, if the distance between the current position of the end of the manipulator 2 and the determined end position exceeds a threshold value, the automatic control means generates a plurality of successive elementary movement control signals to bring the end of the manipulator to the desired end position.

Between each transmission of the elementary displacement control signal, the automatic control means generate an immobilization control signal, and the control means transmit an activation signal from the data acquisition system 4 to obtain a new pair of measurements. This makes it possible to check during the entire movement of the manipulator 2 that its end is approaching the desired end position, and to take into account the possible accidental movement of the patient's head (in this case, the desired end position should be updated).

7. Working principle

Further with reference to Fig. 4 and 5 follows a more detailed description of the principle of operation of the therapeutic equipment.

7.1. Before using the therapy device

As a precondition for normal operation of the above described therapeutic apparatus, it should be clarified that in each location where this apparatus is to be used, the position of the surgical equipment in the operating room with markings on the floor must be determined, and this position is determined depending on:

- surgeon preferences (right or left position, front, side or back, close or far),

- the usual final position of the bed on which the patient lies,

- the shape of the bed, its dimensions, its height,

- compliance with the distance condition in such a way that the final position of the patient's head is in the perimeter centered around the attachment point of the robotic arm on the surgical equipment and symbolizing its radius of action or the distance beyond which the manipulator will not be able to reach the target.

By marking the floor, the therapy device will be positioned in the same place each time it is used. Thus, the relative position of each patient with respect to the machine, and in particular his head and his eyes, is known with a margin of error that can be up to 20 centimeters.

Thus, by means of parameterization performed via the human-machine interface, it is possible to determine the coordinates of the perimeter P corresponding to a square with a side of 50 cm, in which the patient's head will be located for eye therapy using the claimed system (perimeter P of the certain presence of the target). After storing the coordinates of this perimeter P, each time it is used, the control device 5 controls the positioning of the end of the manipulator (by default and before the actions necessary to obtain perfect alignment) in the center of the perimeter P. This position corresponds to the initial deployed position.

Centering and establishing contact of the immobilization element with the eye tissue is performed as follows.

7.2. Automatic positioning of the free end of the manipulator on the eye tissue

7.2.1. Manipulator Deployment

When the patient is seated and the therapy device is in position, the control device 5 instructs to deploy the arm (step 801).

The manipulator 2 moves automatically (as shown by the first four steps in Fig. 5) to position the free end of the manipulator 2 at the center of the perimeter P (original deployed position).

After reaching the center of the perimeter P, iterations of the automatic control loop XY are started.

7.2.2. XY automatic control loop

The XY automatic control loop has a programmed function that at each iteration:

- receives an image,

- analyzes it

- identifies the XY coordinates of the desired final horizontal position,

- determines the X', Y' coordinates of the current horizontal position of the free end of the manipulator 2, and

- calculates the deviation between the current horizontal position and the desired final horizontal position,

- calculates the remaining trajectory between the current horizontal position and the desired final horizontal position,

- transmits to the manipulator 2 one or more movement control signals to set the manipulator 2 in motion along the calculated trajectory until the analysis of the received image allows to determine that the desired final horizontal position has been reached (X=X' and Y=Y'): free the end of the manipulator 2 is thus aligned with the vertical axis passing through the center of the eye tissue.

In particular, the controls of the monitoring device 5 issue an activation signal to the data collection system 4 . The data acquisition system 4 receives an image and a signal characterizing the distance between the end of the manipulator and the ocular tissue.

The processing means receive a pair of measurements received by the data acquisition system 4 and process them (step 803).

In particular, the means of processing:

- ocular tissue is detected in the resulting image,

- determine the position of the center of the eye tissue,

- determine this position of the center of the eye tissue as corresponding to the desired final horizontal position,

- evaluate the current horizontal position of the end of the manipulator, and

- compare (step 804) the current horizontal position with the desired final horizontal position (for example, calculating the distance between the current horizontal position and the desired final horizontal position).

The result of this comparison enters the automatic control means, which:

- give a command to apply the automatic control loop in Z, if the current horizontal position coincides with the desired final horizontal position,

- otherwise generate a control signal for the horizontal movement of the manipulator 2 (step 805).

After moving the manipulator 2 in accordance with the movement control signal, the automatic control means generate a control signal to immobilize (step 806) the manipulator 2, and the previous steps are repeated until the free end of the manipulator 2 comes to the desired final XY horizontal position.

7.2.3. Automatic Z loop

After the free end of the manipulator 2 is XY aligned with the desired final horizontal position, you can apply the automatic control loop in Z.

The Z-loop is a programmed function that, at each iteration:

- receives data on the current height of the location of the end of the manipulator 2 in relation to the eye tissue (the current position Z' - the desired position Z),

- calculates the deviation between the current vertical position of the end of the manipulator and the desired final vertical position,

- transmits to the manipulator 2 one or more movement control signals in order to set the manipulator 2 in motion along the Z axis, without changing the XY position, along the calculated trajectory until the moment when the force sensor 3 detects a contact corresponding to the fact that the desired end point has been reached vertical position (Z'=Z): the free end of the manipulator 2 comes into contact with the ocular tissue.

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

The result of this comparison is transmitted to the automatic control means, which also receive the signal measured by the force sensor 3 . Means of automatic control:

- generate a control signal immobilization of the manipulator 2, if the current vertical position matches the desired final vertical position (step 810),

- otherwise generate a control signal for the vertical movement of the manipulator 1 (step 808).

After moving the arm 2 in accordance with the vertical movement control signal, the automatic control generates the immobilization control signal (step 809), and the previous steps are repeated, including the XY automatic control loop steps to check that the current horizontal position is still desired final horizontal position.

This makes it possible to take into account the possible movements of the patient during the positioning procedure of the manipulator 2.

The control device 5 makes it possible to position the free end of the manipulator accurately and with the correct centering. At this free end, various working components are installed to allow treatment of the ocular tissue.

For the physician's greater certainty, the sequence of the various steps shown in FIG. 4 can be controlled with a foot control and/or voice command and/or with a touch or other type of human-machine interface.

8. Conclusions

The invention described above makes it possible to automatically position the eyeball immobilization element on the patient's eye in just a few seconds without human intervention, quickly, accurately and reproducibly. Its effectiveness is independent of the environment, which allows you to win in accuracy, make the action reproducible, no matter the patient or operator, and get time savings, making it easier for the operator to work at little cost.

In addition, the invention allows to achieve a greater level of safety and, therefore, reduce the risk to the patient during the intervention.

It is understood that many changes can be made to the invention described above without materially departing from the new knowledge and advantages described herein. For example, in the present description, the immobilization element is mounted on the free end of the robotic arm. In a variant, the immobilization element can be separated from the robotic arm. In this case, the immobilization element is positioned on the patient's eye before the robotic arm is moved, and the desired end position corresponds to establishing contact of the free end of the robotic arm with the side of the immobilization element opposite to the surface of the immobilization element coming into contact with the eye. Therefore, all changes of this type are to be included within the scope of the appended claims.

Claims (69)

1. Device (5) for controlling the movement of an ophthalmic therapy device, containing: - a manipulator (2), while the free end of the manipulator (2) is designed to be placed opposite the human or animal eye tissue, the specified manipulator (2) is articulated to ensure the movement of the free end of the manipulator (2) along three pairwise orthogonal axes X, Y and Z : along the X axis, which defines the horizontal longitudinal direction, along the Y axis, which defines the horizontal transverse direction, which together with the X axis forms the horizontal XY plane, along the Z axis, which defines the vertical direction perpendicular to the horizontal XY plane, - data acquisition system (4) installed on the manipulator (2) and designed to obtain a pair of measurements, including: image of eye tissue and a signal characterizing the vertical distance along the Z axis between the end of the manipulator (2) and the eye tissue, characterized in that the control device (5) contains: - means for controlling the system (4) of data collection to obtain pairs of measurements sequentially in time, means for processing each pair of measurements, said processing means including: means for estimating, based on the current pair of measurements, the vertical distance along the Z axis between the end of the manipulator and the eye tissue, means of calculating, based on the image of the current pair of measurements, the horizontal deviation between: the current horizontal position of the free end of the manipulator in the horizontal XY plane, and a certain final horizontal position of the free end of the manipulator in the horizontal XY plane, means of automatic control, made with the possibility of: if the calculated horizontal deviation exceeds the first threshold value, generate a control signal for horizontal movement of the manipulator (2) in the horizontal XY plane in order to reduce the deviation between the current horizontal position and the determined final horizontal position, if the calculated horizontal deviation is less than the first threshold value and if the estimated vertical distance exceeds the second threshold value, generate a control signal to vertically move the manipulator (2) in the vertical direction to reduce the distance between the free end of the manipulator and the ocular tissue, if the calculated horizontal deviation is less than the first threshold value and if the measured vertical distance is less than the second threshold value, generate a control signal to bring the manipulator to a stationary state. 2. The control device according to claim 1, in which the calculation means contain: - means for detecting, based on the image of the current pair of measurements, the horizontal position of at least one point of interest in the eye tissue, means for estimating, based on the detected horizontal position of the point of interest, the horizontal deviation between: the current horizontal position of the free end of the manipulator in the horizontal XY plane and a certain final horizontal position of the free end of the manipulator in the horizontal XY plane. 3. The monitoring device according to claim 2, wherein the detection means are configured to identify ocular tissue in the acquired image by applying a shape recognition algorithm to detect three concentric circles in the image. 4. Control device according to any one of paragraphs. 1-3, in which the therapeutic device further comprises a force sensor (3) mounted on the free end of the manipulator to measure the mechanical force applied to the free end of the manipulator: wherein the processing means comprise means for comparing said measured mechanical force with a third threshold value in order to determine whether the free end of the manipulator comes into contact with an element that forms an obstacle to the vertical movement of the manipulator along the Z axis, said means of automatic control are programmed in such a way as to generate a control signal to bring the manipulator to a stationary state if the measured mechanical force exceeds the third threshold value. 5. Control device according to any one of paragraphs. 1-4, in which to obtain a signal characterizing the vertical distance along the Z axis, the data acquisition system comprises: - means for obtaining data by means of laser telemetry, and/or - means for obtaining data using ultrasound, means for obtaining data through image processing. 6. The control device according to any of the preceding claims, in which the automatic control means are programmed in such a way as to generate control signals of an elementary movement to ensure the movement of the manipulator between its current position and a certain end position, while said automatic control means generate a control signal to bring to a standstill state following each elementary move control signal. 7. A method for controlling the movement of an ophthalmic therapy device, comprising: - a manipulator (2), while the free end of the manipulator (2) is designed to be placed opposite the human or animal eye tissue, the specified manipulator (2) is articulated to ensure the movement of the free end of the manipulator (2) along three pairwise orthogonal axes X, Y and Z : along the X axis, which defines the horizontal longitudinal direction, along the Y axis, which defines the horizontal transverse direction, which together with the X axis forms the horizontal XY plane, along the Z axis, which defines the vertical direction perpendicular to the horizontal XY plane, - a data acquisition system (4) installed on the manipulator (2) and designed to obtain a pair of measurements, including: image of eye tissue and a signal characterizing the vertical distance along the Z axis between the end of the manipulator and the eye tissue, characterized in that the method of control contains the following phases, in which: - receive (802) pairs of measurements sequentially in time using the data acquisition system, - processing (803) each pair of measurements, while the processing phase contains the steps in which: estimate the vertical distance along the Z axis between the end of the manipulator and the ocular tissue based on the current pair of measurements, based on the image from the current pair of measurements, calculate the horizontal deviation between: the current horizontal position of the free end of the manipulator in the horizontal XY plane and a certain final horizontal position of the free end of the manipulator in the horizontal XY plane, - perform automatic regulation of the movement of the manipulator (2), while: if the calculated horizontal deviation exceeds the first threshold value, a control signal is generated (805) for the horizontal movement of the manipulator (2) in the horizontal XY plane in order to reduce the deviation between the current horizontal position and the specified defined final horizontal position, if the calculated horizontal deviation is less than the first threshold value and if the estimated vertical distance exceeds the second threshold value, a control signal is generated (808) to vertically move the manipulator (2) in the vertical direction to reduce the distance between the free end of the manipulator and the ocular tissue, if the calculated horizontal deviation is less than the first threshold value and if the measured vertical distance is less than the second threshold value, a control signal is generated (810) to bring the manipulator to a stationary state. 8. The control method according to claim 7, wherein the calculation step comprises sub-steps, in which: - based on the image from the current pair of measurements, the horizontal position of at least one point of interest in the eye tissue is detected, - based on the detected horizontal position of the point of interest, estimate the horizontal deviation between: the current horizontal position of the free end of the manipulator in the horizontal XY plane and the specified end horizontal position of the free end of the manipulator in the horizontal XY plane. 9. The inspection method according to claim 8, wherein the detection substep identifies ocular tissue in the acquired image by applying a shape recognition algorithm to detect three concentric circles in the image. 10. The method of control according to any one of paragraphs. 7-9, in which the therapeutic device further comprises a force sensor (3) mounted on the free end of the manipulator (2) to measure the mechanical force applied to the free end of the manipulator: wherein the processing phase comprises the step of comparing said measured mechanical force with a third threshold value in order to determine whether the free end of the manipulator comes into contact with an element that forms an obstacle to the vertical movement of the manipulator along the Z axis, - at the stage of automatic control, a control signal is generated to bring the manipulator to a stationary state if the measured mechanical force exceeds the third threshold value. 11. The method of control according to any one of paragraphs. 7-10, in which, in the data acquisition phase: - receive signal data characterizing the vertical distance along the Z-axis, by means of laser telemetry, and/or - receive signal data characterizing the vertical distance along the Z-axis, by means of ultrasound, and/or - select the resulting image from the signal characterizing the vertical distance along the Z axis. 12. The control method according to any one of paragraphs. 7-11, in which at the stage of automatic control: - generate an elementary movement control signal to move the manipulator between its current position and a certain end position, - generate a control signal to bring to a stationary state after each control signal of the elementary movement, - repeat the previous sub-steps until the calculated horizontal deviation is less than the first threshold value and until the measured vertical distance is less than the second threshold value.

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