Articulated arm for supporting a catheter robot for handling flexible medical instruments, with extension and including a brake

Abstract

The invention relates to an articulated support arm for a robotic catheter for manipulating elongated flexible medical instruments, comprising: a segment carried by a shaft (5) rotatable about an axis of rotation; a magnetic brake (2) for locking the segment against rotation about the axis of rotation, comprising: an electromagnet (21) coupled to a power supply; a braking disc (22) movable between: on the one hand, a braking position in which the braking disc (22) is attracted against the electromagnet (21), and on the other hand, a release position in which the braking disc (22) is not attracted against the electromagnet (21) but is moved away from the electromagnet (21) when the latter is powered; at least one reduction gear (3, 4) disposed between the shaft (5) of the segment and the magnetic brake (2) and configured to reduce the torque applied to the magnetic brake (2) by the segment. Figure 2

Description

Title of the invention: ARTICULATED SUPPORT ARM for a catheter robot for manipulating an elongated flexible medical instrument, INCLUDING A BRAKE. FIELD OF THE INVENTION

[0001] The invention relates to the technical field of articulated arms for supporting a catheter robot for manipulating an elongated flexible medical instrument, including a brake. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] According to prior art, an articulated arm for supporting a flexible medical instrument catheter for manipulating a robotic catheter is known, comprising a hydraulic brake. This solution is described in document FR3103096.

[0003] This hydraulic brake is very effective because it offers high hydraulic braking power.

[0004] However, this hydraulic brake has a hydraulic fluid supply structure which is on the one hand relatively complex, and on the other hand subject to a risk of hydraulic fluid leakage during its use. OBJECTS OF THE INVENTION

[0005] The object of the present invention is to provide an articulated arm for supporting a catheter robot for manipulating an elongated flexible medical instrument, comprising a brake that at least partially overcomes the aforementioned disadvantages.

[0006] More particularly, the invention aims to provide an articulated support arm for a catheter robot for handling an elongated flexible medical instrument comprising a brake whose overall structure is simpler.

[0007] However, according to the invention, it would also be advantageous for the brake used, while being structurally simpler, to offer a good compromise between the braking power provided, which should be high, and the weight and size of the braking system used, which should remain limited in weight and volume. This is all the more important since this braking system will have to be integrated onto an articulated arm where, as one moves from the proximal to the distal end of the articulated arm: • a high weight becomes more problematic due to a lever arm effect, • the larger the volume, the more bothersome it becomes, due to the proximity of the patient and other medical devices that can be used.

[0008] The invention proposes the use of: • a magnetic brake, • which is structurally simpler than a hydraulic brake, and which does not pose the risk of using pressurized fluid, • but coupled with a torque reducer (advantageously a mechanical reducer) (instead of being used alone) applied to the magnetic brake, with a sufficiently high overall reduction factor, to compensate for the intrinsically rather low nature of the magnetic braking power, • thus greatly reducing the torque applied to the magnetic brake by the force exerted both by the own weight of the articulated arm and by the arm of a practitioner wishing to manually move the articulated arm, • so as to allow the intrinsically relatively limited range of braking power of the magnetic brake to nevertheless be sufficient to perform effective braking.

[0009] The invention proposes an articulated arm for supporting a flexible medical instrument catheter robot, comprising a magnetic brake coupled with a high reduction factor reducer, to satisfy the following triple compromise: • simple structure braking system, • braking system providing sufficiently high braking power, • braking system with reduced weight and limited size.

[0010] To this end, the present invention proposes an articulated arm for supporting a robotic catheter for manipulating an elongated flexible medical instrument, comprising: a segment carried by a shaft movable in rotation about an axis of rotation, a magnetic brake for locking the segment in rotation about the axis of rotation, comprising: an electromagnet coupled to an electrical power supply, a braking disc movable between: on the one hand, a braking position in which the braking disc is attracted against the electromagnet when the latter is not powered, thus locking the segment in rotation about the axis of rotation, and on the other hand, a release position in which the braking disc is not attracted against the electromagnet but is moved away from the electromagnet when the latter is powered, thus releasing the segment in rotation about the axis of rotation.at least one reduction gear disposed between the segment shaft and the magnetic brake and configured to reduce the torque applied to the magnetic brake by the segment.

[0011] Preferably, the brake is movable by translation along an axis parallel to the axis of rotation, or along the axis of rotation, of the rotation shaft of the segment.

[0012] According to preferred embodiments, the invention comprises one or more of the following features which can be used separately or in partial combination with each other or in total combination with each other.

[0013] Preferably, the reducer(s) together have an overall reduction factor for said torque that is greater than 10, or greater than 20, or between 20 and 40.

[0014] Thus, the weight and size of the magnetic brake are further reduced, while maintaining a sufficient braking power.

[0015] Preferably, the reducer(s) together have an overall reduction factor of said torque which is less than 50, or less than 40.

[0016] Thus, the weight and size of the magnetic brake are further reduced, while maintaining a sufficient braking power.

[0017] Preferably, the articulated arm comprises: at least two reducers, or advantageously only two reducers, of said rotational torque applied to the magnetic brake by the segment, which are arranged in cascade with respect to each other, so that the overall reduction factor of the assembly formed by these two reducers is the product of their respective reduction factors, one of the reducers being connected to the magnetic brake, the other reducer being connected to the shaft of the segment.

[0018] Advantageously, the articulated arm comprises: at least two reducers, or advantageously only two reducers, a first reducer and a second reducer, having respectively a first reduction factor and a second reduction factor, of the rotational torque applied to the magnetic brake by the segment, which are arranged in cascade with respect to each other, so that the overall reduction factor, of the assembly formed by the first reducer and the second reducer, of the rotational torque applied to the magnetic brake by the segment, is the product of the first reduction factor by the second reduction factor.

[0019] Advantageously, the first reducer is connected to the magnetic brake, while the second reducer is connected to the segment shaft. If there is a third reducer, it will be located between the first and second reducers, as will a possible fourth reducer, all the reducers being arranged in cascade, so that the overall reduction factor of the set formed by these reducers is the product of their respective reduction factors.

[0020] Thus, the weight and size of the magnetic brake are further reduced, while retaining the simplicity and robustness of the magnetic brake.

[0021] Preferably, the reducers each have an individual reduction factor which is between 3 and 7.

[0022] Thus, the weight and size of the magnetic brake are further reduced, while maintaining a sufficient braking power supply, because the braking effort is even more harmoniously distributed between the different reducers (advantageously two reducers).

[0023] Preferably, one of the reducers is fixed to the brake disc so as to rotate at the same speed as it, the other reducer is fixed to the rotation shaft of the segment so as to rotate at the same speed as it.

[0024] Thus, the weight and size of the magnetic brake are further reduced, while retaining the simplicity and robustness of the magnetic brake.

[0025] Preferably, the articulated arm comprises: the reducer(s) are epicyclic reducers, each comprising several elements which cooperate with each other, among which: a planet carrier, a planet connected to the planet carrier, a ring gear, one or more satellites, or 3 satellites, disposed between the planet and the ring gear, and preferably distributed symmetrically around the planet.

[0026] Thus, the weight and size of the magnetic brake are further reduced, while retaining the simplicity and robustness of the magnetic brake.

[0027] Preferably, the brake disc includes a brake lining which: on the one hand, in the braking position, is pressed against the electromagnet when the latter is not supplied with electricity, thus blocking the segment from rotating around the axis of rotation, and on the other hand, in the release position, is not pressed against the electromagnet but is moved away from the electromagnet when the latter is supplied with electricity, thus releasing the segment from rotating around the axis of rotation, the brake lining being a wear part which is replaceable, the brake lining being advantageously magnetized.

[0028] Thus, the handling over time of the magnetic braking system is made simpler and less expensive, while maintaining braking efficiency.

[0029] Preferably, the attraction of the brake disc against the electromagnet blocks, but does not lock, the segment rotating around the axis of rotation.

[0030] Thus, in case of emergency for example, the rotating segment is only blocked but not locked, and therefore it can be unlocked more quickly and more easily by the user, for example by sufficiently strong pressure from the user which will cause the emergency unlocking of the rotating segment(s) and even possibly of the entire articulated arm.

[0031] By way of example, we can distinguish: • Non-lock braking: • If you push the arm a little by accidentally hitting it or by pressing lightly, typically with a force between 5N and 20N, the arm moves, but less than if there was no braking; • Blocking without locking: • If you push the arm slightly by accidentally giving it a blow, the arm does not move but remains in position. • For the arm to move, the user must either push or pull on it with a significant force, typically a force applied by a user between 30N and 50N, • Locking mechanism: • If you want to move and adjust the arm, you have to break (or damage) all or part of the locking and blocking mechanism (unless of course you have unlocked it beforehand).

[0032] Preferably, the segment rotates around its axis of rotation by means of a needle bearing or several needle bearings located radially between the axis of rotation and the segment.

[0033] Thus, the rotation of the segment around its axis of rotation is better balanced and the articulated arm experiences less wear overall over time. Furthermore, the size of the rotating segment, and consequently also the overall size of the articulated arm, is slightly reduced.

[0034] Preferably, the articulated arm comprises: at least three segments articulated in rotation with respect to each other, around the same direction of rotation, among which: a proximal segment, located closest to the operating table when the articulated arm is fixed on this operating table, a distal segment, carrying the elongated flexible medical instrument handling catheter robot, an intermediate segment, located between the proximal segment and the distal segment.

[0035] Preferably, the articulated arm comprises: at least four segments articulated in rotation with respect to each other, around the same direction of rotation, among which: a proximal segment, located closest to the operating table when the articulated arm is fixed on this operating table, a distal segment, carrying the elongated flexible medical instrument handling catheter robot, at least two intermediate segments, located between the proximal segment and the distal segment.

[0036] Thus, the fluidity in rotation (when the segment(s) are in motion), the efficiency of blocking in rotation (when the segment(s) are immobile), as well as the overall bulk of the articulated arm, are all made more important as the structure of the articulated arm is complex and long.

[0037] Preferably, the elongated flexible medical device comprises a catheter and / or a catheter guidewire and / or a guide catheter. The catheter may be a balloon catheter, a stent catheter, or a microcatheter.

[0038] This intervention robot is used to introduce this elongated flexible medical organ into the blood circulatory system of a patient, for example.

[0039] Other features and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention, given by way of example and with reference to the accompanying drawings. Brief description of the drawings

[0040] [Fig-1] Fig. 1 schematically represents an example of an articulated arm of catheter robot support according to an embodiment of the invention.

[0041] [Fig.2] Figure 2 schematically represents an example of a braking system installed on the articulated arm of the [Fig. 1].

[0042] [Fig.3] Fig.3 schematically represents a cross-sectional view of the system of braking of the [Fig.2].

[0043] [Fig.4] Fig.4 schematically represents an example of a reducer of the system braking of the [Fig.2].

[0044] DETAILED DESCRIPTION OF THE METHODS OF EMBODIMENT OF THE INVENTION

[0045] In the variant illustrated in [Fig. 1], a catheter robot support arm 100 for manipulating an elongated flexible medical instrument is a three-axis articulated arm comprising two segments: a proximal segment 101 fixed to the base 103 of the articulated arm, and a distal segment 102 to which the catheter robot is attached. Each segment includes a pivot at each of its two ends, one pivot being common to both segments, thus forming the three axes of the articulated arm. The pivots of the segments comprise a shaft 5 that rotates about an axis of rotation, the axes of rotation all being oriented vertically in the variant illustrated in [Fig. 1]. The number of axes of the articulated arm 100 and their orientation may vary.

[0046] The articulated arm 100 includes a braking system 1 installed on each of the segment pivots. The variant illustrated in [Fig. 1] of the articulated arm 100 therefore includes three braking systems 1 which make it possible to block the rotation of the segments around the shafts 5.

[0047] As illustrated in Figures 2 and 3, the braking system 1 comprises:

[0048] - a magnetic braking system 2 which is in the braking position when it is not powered;

[0049] - a first epicyclic reducer 3 which is connected to the magnetic braking system 2;

[0050] - a second epicycloidal reducer 4 which connects the first epicycloidal reducer 3 to tree 5.

[0051] The magnetic braking system 2 comprises:

[0052] - an electromagnet 21;

[0053] - a brake disc 22 which is movable between a braking position in which said brake disc 22 is attracted by the electromagnet 21 so as to be pressed against said electromagnet 21, and a release position in which said brake disc 22 is no longer attracted by the electromagnet 21 and is located at a distance from said electromagnet 21.

[0054] The rotation of the brake disc 22 is braked by friction with the electromagnet 21 when said brake disc 22 is in the braking position, while the rotation the brake disc 22 is free when said brake disc 22 is in the release position.

[0055] The electromagnet 21 is configured to attract the brake disc 22 when said electromagnet 21 is not electrically powered, and to cease attracting or repelling the brake disc 22 when said electromagnet 21 is electrically powered. Thus, in the event of a power outage to the articulated arm 100, the braking system 1 remains active and maintains said articulated arm 100 in position.

[0056] Preferably, the brake disc 22 comprises a brake lining 220, which may also be made of a magnetic material so as to be attracted by the electromagnet 21. The brake lining 220 is fixed on the brake disc 22 and is intended to be pressed against the electromagnet 21 when the brake disc 22 passes into its braking position by being attracted by the electromagnet 21.

[0057] The brake lining 220 is a wear part that can be replaced during a maintenance operation.

[0058] In one possible embodiment, the brake lining 220 can be pressed against the electromagnet 21 by the attraction of the brake disc 22 by the electromagnet 21, the brake lining 220 not being made of a magnetic material. In another possible embodiment, in which the brake lining 220 is made of a magnetic material, the brake lining 220 is pressed against the electromagnet by the combined effect of the attraction of the brake disc 22 and the attraction of the brake lining 220 by the electromagnet 21.

[0059] The first epicyclic reducer 3 comprises a planet gear 31 which is connected to the brake disc 22, the planet gear 31 rotating at the same speed as the brake disc 22. The first epicyclic reducer 3 also comprises a plurality of planet gears 32, a ring gear 33, and a planet carrier 34. Such a structure makes it possible to limit the overall size of the first epicyclic reducer 3 while allowing a satisfactory reduction ratio.

[0060] Preferably the first epicycloidal reducer 3 comprises three satellites 32 regularly distributed around the planetary 31.

[0061] The second epicyclic reducer 4 comprises a planet gear 41 which is connected to the planet carrier 34 of the first epicyclic reducer 3, the planet gear 41 of the second epicyclic reducer 4 rotating at the same speed as the planet carrier 34 of the first epicyclic reducer 3. The second epicyclic reducer 4 also comprises a plurality of planet gears 42, a ring gear 43, and a planet carrier 44. Such a structure makes it possible to limit the size of the second epicyclic reducer 4 while allowing a satisfactory reduction ratio.

[0062] Preferably the second epicycloidal reducer 4 comprises three satellites 42 regu- loosely distributed around planetary 41.

[0063] The shaft 5 is connected to the planet carrier 44 of the second epicycloidal reducer 4, the planet carrier 44 of the second epicycloidal reducer 4 rotating at the same speed as the shaft 5.

[0064] The use of two epicyclic reducers in parallel makes it possible to obtain the desired reduction factor. Thus, according to one possible variant, a reduction factor of 30 is obtained by stacking a first epicyclic reducer 3 with a factor of 6 and a second epicyclic reducer 4 with a factor of 5, or by stacking a first epicyclic reducer 3 with a factor of 5 and a second epicyclic reducer 4 with a factor of 6.

[0065] Advantageously, the reduction factor obtained for each braking system 1 is greater than 10. Even more advantageously, the reduction factor is greater than 20. Even more advantageously, the reduction factor is between 20 and 40. Moreover, the reduction factor is preferably less than 50, and even more preferably less than 40.

[0066] Figure 4 is a view showing the interior of the first epicycloidal reducer 3. On the [Fig.4] only two satellites 32 are illustrated, one satellite 32 being removed to simplify understanding.

[0067] In the variant illustrated in the figures, the articulated arm 100 comprises only two segments. However, a larger number of segments and axes are possible. In particular, the articulated arm 100 may include one or more intermediate segments located between the proximal segment 101 and the distal segment 102.

[0068] Furthermore, advantageously, the articulated arm 100 can be configured so that an operator can overcome the braking torque of at least one of the braking systems 1 installed on the axes of said articulated arm 100 by pushing or pulling with a significant force on said articulated arm, for example, a force between 30 N and 50 N, preferably between 30 N and 40 N, even though the brakes are engaged. This feature allows for emergency release of the articulated arm 100 even in the event of a power outage, the articulated arm 100 being held in place by the braking systems 1, but not locked.

[0069] Furthermore, the braking systems 1 are preferably configured so that an operator can move the articulated arm 100 by pulling or pushing with a low force when the braking is deactivated, the low force being, for example, between 5N and 20N, preferably between 5N and 15N. This feature allows for easier use of the articulated arm 100, as the user only needs to deactivate the braking via a control unit. The control unit is configured to control the activation or deactivation of the braking of each braking system 1 by cutting off or opening the power supply to the electromagnets 21. The control unit may, for example, include a button that deactivates the braking. that an operator presses it, and reactivates the braking when the operator releases said button.

[0070] Of course, the present invention is not limited to the examples and embodiment described and represented, but is susceptible to many variations accessible to those skilled in the art.

Claims

1.

2.

3. Demands Articulated arm (100) for supporting a flexible medical instrument handling catheter robot, comprising: • a segment (101, 102) carried by a shaft (5) that rotates about an axis of rotation, • a magnetic brake (2) for locking the segment (101, 102) in rotation around the axis of rotation, comprising: • an electromagnet (21) coupled to a power supply, • a movable brake disc (22) between: • on the one hand, a braking position in which the brake disc (22) is attracted against the electromagnet (21) when the latter is not powered, thus blocking the segment (101, 102) from rotating around the axis of rotation, • and on the other hand a release position in which the brake disc (22) is not attracted against the electromagnet (21) but is moved away from the electromagnet (21) when the latter is powered, thus freeing the segment (101, 102) to rotate around the axis of rotation, • at least one reducer (3, 4) disposed between the shaft (5) of segment (101, 102) and the magnetic brake (2) and configured to reduce the torque applied to the magnetic brake (2) by segment (101, 102), • the reducer(s) (3, 4) together having an overall reduction factor of said torque which is greater than 10, or greater than 20, or between 20 and 40. Articulated arm (100) according to claim 1, characterized in that the reducer(s) (3, 4) together have an overall reduction factor of said torque which is less than 50, or less than 40. Articulated arm (100) according to any one of the preceding claims, characterized in that it comprises: • at least two reducers (3,4), or advantageously only two reducers (3,4), of said rotational torque applied to the magnetic brake (2) by the segment (101, 102), which are arranged in cascade with respect to each other, so that the overall reduction factor of the assembly formed by these at least two reducers (3, 4) is the product of their respective reduction factors, • one of the reducers (3) being connected to the magnetic brake, • the other reducer (4) being connected to the shaft (5) of the segment (101, 102).

4. Articulated arm (100) according to claim 3, characterized in that the reducers (3, 4) each have an individual reduction factor which is between 3 and 7.

5. Articulated arm (100) according to claim 3 or claim 4, characterized in that: • one of the reducers (3) is fixed to the brake disc (22) so as to rotate at the same speed as it, • the other reducer (4) is fixed to the shaft (5) of rotation of the segment (101, 102) so as to rotate at the same speed as it.

6. Articulated arm (100) according to any one of the preceding claims, characterized in that it comprises: • the reducer(s) (3, 4) are epicyclic reducers, each comprising several elements which cooperate with each other, among which: • a planet carrier (34, 44), • a planet (31, 41) connected to the planet carrier (34, 44), • a ring gear (43), • one or more planets (32, 42), or 3 planets (32, 42), disposed between the planet (31, 41) and the ring gear (33, 43), and preferably distributed symmetrically around the planet (31, 41).

7. Articulated arm (100) according to any one of the preceding claims pedentes, characterized in that: • the brake disc (22) comprises a brake lining (220) which: • on the one hand, in the braking position, is pressed against the electromagnet (21) when the latter is not supplied with electricity, thus blocking the segment (101, 102) from rotating around the axis of rotation, • and on the other hand, in the release position, is not pressed against the electromagnet (21) but is moved away from the electromagnet (21) when the latter is supplied with electricity, thus releasing the segment (101, 102) from rotating around the axis of rotation, • the brake lining (220) being a wear part which is replaceable, • the brake lining (220) being advantageously magnetized.

8. Articulated arm (100) according to any one of the preceding claims, characterized in that the attraction of the brake disc (22) against the electromagnet (21) blocks, but does not lock, the segment (101, 102) in rotation about the axis of rotation.

9. Articulated arm (100) according to any one of the preceding claims, characterized in that the segment (101, 102) rotates about its axis of rotation by means of a needle bearing or several needle bearings located radially between the axis of rotation and the segment (101, 102).

10. An articulated arm (100) according to any one of the preceding claims, characterized in that it comprises: • at least three segments (101, 102) articulated in rotation with respect to each other, about the same direction of rotation, among which: • a proximal segment (101), located closest to the operating table when the articulated arm (100) is fixed to this operating table, • a distal segment (102), carrying the elongated flexible medical instrument catheter manipulation robot, • an intermediate segment, located between the segment proximal (101) and distal segment (102).

11. Articulated arm (100) according to any one of the preceding claims, characterized in that it comprises: • at least four segments (101, 102) articulated in rotation with respect to each other, around the same direction of rotation, among which: • a proximal segment (101), located closest to the operating table when the articulated arm (100) is fixed to this operating table, • a distal segment (102), bearing the elongated flexible medical instrument handling catheter robot, • at least two intermediate segments, located between the proximal segment (101) and the distal segment (102).

12. Articulated arm (100) according to any one of the preceding claims, characterized in that the elongated flexible medical instrument comprises a catheter and / or a catheter guide and / or a catheter guide.