FR3117768A1 - Instrument head, corresponding instrument and installation - Google Patents

Abstract

The invention relates to an instrument head (1) comprising a first element and at least one second element movably mounted on the first element between an inactive position and an active position, the head thus being provided with means for relative displacement of the second element vis-à-vis the first element, said means comprising at least one preformed rod having a first shape when the rod is outside the head in the rest state, the rod being arranged in the head so as to extend both in the first element and both in the second element so that in the inactive position of the second element, the rod is forced into a second shape different from the first shape, the rod thus gradually returning to its first shape when the second element moves to its active position. The invention also relates to an instrument as well as an installation provided with such a head. FIGURE OF THE ABRIDGE: [Fig.3b]

Description

Instrument head, corresponding instrument and installation

The invention relates to an instrument head. The invention also relates to an instrument comprising such a head and a corresponding installation.

BACKGROUND OF THE INVENTION

During the development of a fetus, an obstacle may appear at the level of the posterior urethra preventing the flow of fetal urine. This lower urinary obstruction (or LUTO = Lower Urinary Tract Obstruction) is a rare congenital malformation that causes progressive deterioration of the fetal urinary system. In particular, the bladder will thicken, stiffen and its wall will crenate. The urethra and excretory cavities will dilate. The development of the kidneys will be progressively altered with the formation of multiple cysts which sign their destruction.

However, it is possible to avoid this degradation by performing an antenatal operation.

At present, two techniques are known: the placement of a vesico-amniotic drain and feto-cytoscopy.

The installation of a vesico-amniotic drain consists in diverting urine directly from the bladder of the fetus to the pocket of amniotic fluid via a pigtail drain.

However, this technique presents specific complications related to frequent obstruction of the drain and/or subsequent displacement of the drain caused by movements of the fetus. In addition it interrupts the natural cycle of filling-emptying the bladder of the fetus, which cannot then develop properly.

The fetal cytoscopy technique, on the other hand, consists in destroying the obstacle by inserting, via the fetal bladder, a perforation tool into the urethra. Once the obstacle is destroyed, the urinary system can continue to develop normally.

This technique is therefore more advantageous in that it allows a more physiological treatment, respecting the repletion-emptying cycle of the fetal bladder.

However, if the obstacle is relatively far from the bladder in the urethra, the tool may have difficulty reaching it. Indeed, it is necessary to be able to bend the tool significantly so that it can penetrate the urethra, a long and very narrow corridor. Thus in adult women, the urethra is about 3 centimeters long with a diameter of about 3 millimeters. This diameter is therefore further reduced for a fetus.

This results in numerous failed operations ranging from the impossibility of treatment to the degradation of the urinary system, the perforation tool being able to touch or perforate the walls of the urinary system while trying to reach the obstacle. This can lead to the death of the fetus.

Difficulties in accessing narrow and/or curved areas do not only concern the fetus and/or the urethra. Indeed, we find these same difficulties on the body of an infant, child or adult and/or for other organs such as the brain, the ears, the olfactory ducts...

OBJECT OF THE INVENTION

An object of the invention is to propose an instrument head making it easier to be able to move inside a body, in particular in narrow and/or curved areas.

An object of the invention is also to provide an instrument comprising such a head.

An object of the invention is also to provide an installation comprising such an instrument.

With a view to achieving this object, the invention proposes an instrument head comprising a first element and at least one second element mounted movably on the first element between an inactive position and an active position, the head thus being provided with means of relative movement of the second element vis-à-vis the first element, said means comprising at least one preformed rod having a first shape when the rod is outside the head in the rest state, the rod being arranged in the head of so as to extend both into the first element and both into the second element so that, in the inactive position of the second element, the rod is forced into a second shape different from the first shape, the rod thus gradually resuming its first shape when the second element moves to its active position.

Thus, in service, the rod enters and exits the first element to follow the movement of the second element and/or enters and exits the second element to allow movement of the second element. This allows the invention to be able to follow an overall trajectory which is predetermined since the rod tends to return to its first shape when it leaves the second element and/or the first element.

It is noted that the invention deploys automatically according to this predetermined overall trajectory (since defined by the first shape of the rod) which greatly facilitates the work of an operator.

In particular, it is therefore possible to insert the invention even in narrow and/or curved areas of a body. All you have to do is preform the rod so that it deforms in the desired path. The invention is particularly interesting for navigating in a narrow and/or fragile area (light and/or cavity and/or conduit, etc.).

The overall deployment trajectory of the invention is therefore pre-programmed and controllable.

Advantageously, each movable element vis-à-vis another element has its own deployment movement which is independent of that of the other elements and which can therefore be identical or different depending on the way in which the associated rod is preformed.

The invention is therefore not limited to simple pivoting between the elements. By playing on the number of elements and/or on the first shape of one, several or all the rods, it is possible to have the invention draw multiple possible global trajectories that are more or less complex and of more or less large amplitudes. The invention can advantageously be deployed along an overall trajectory of small dimensions or, on the contrary, of large dimensions. The invention can also be deployed in a fine manner. The invention can move along a circular global trajectory or else according to a more complex global trajectory for example in S, in zig-zag... The global trajectory can be in two dimensions, in three dimensions, circular, non-circular, rectilinear, not rectilinear … The global trajectory can be a curve whose center of curvature is offset with respect to a general axis along which extends a plate of an instrument carrying the head and/or an axis along which extends the end distal to the head (i.e. the end of the head attached to the instrument). The trajectory can also be a bending without sweeping space.

The invention advantageously allows intelligent articulation between the various elements jointly forming a serial chain of the spine or even crutch type.

The invention can thus be deformed in various ways, which offers multiple possibilities in terms of interventions. The invention is indeed adaptable to the required need.

In the particular, but non-limiting, case where the invention is used for feto-cytoscopy, it is possible to shape the rod or rods so that the invention can follow during its extension (by moving each of its mobile elements in their respective active position) the curvature drawn between the urethra and the bladder and then the narrow shape of the urethra itself. In case of LUTO, it is therefore possible to equip the invention with a puncture tool, greatly facilitating the task of a surgeon.

As indicated above, the invention can of course be used in many other applications such as neurosurgery, cardiac surgery, etc. Other examples of applications will thus be given in the remainder of the description.

According to another aspect, the invention proves to be relatively simple to manufacture.

According to yet another aspect, the invention can be of small dimensions.

Optionally, the head comprises at least one third element mounted to move on the second element between an inactive position and an active position, the relative displacement means comprising at least a second preformed rod having a first shape when the second rod is outside the head at the rest state, the second rod being arranged in the head so as to extend at least into the second element and the third element so that in the inactive position of the third element, the second rod is forced into a second different shape of the first shape of the second rod, the second rod thus gradually resuming its first shape when the third element moves towards its active position.

Optionally the second rod also extends into the first element.

Optionally, the head comprises at least one additional rod also making it possible to ensure the relative displacement of the second element with respect to the first element.

Optionally, the first rod and the second rod making it possible to ensure the relative displacement of the second element with respect to the first element have first different shapes.

Optionally the rod is fixed to the first element or to the second element.

Optionally in the inactive position of the second element, the first element and the second element are in contact with each other.

Optionally in the inactive position of the second element, the first element and the second element extend coaxially with respect to each other.

Optionally, the first element and the second element have a cross section of the same shape and/or of the same dimensions.

Optionally in the inactive position of the second element, the rod is arranged entirely inside the head.

Optionally the rod is preformed so as to be curved in its first shape.

Optionally the relative displacement means also comprise actuation means which comprise at least one actuation pin.

Optionally the rod is fixed to said pin.

Optionally at least one of the elements has a diameter of less than 3 millimeters.

Optionally the stem is preformed so that in its first shape the stem draws a sector curve with an angle between 40 and 80 degrees.

Optionally, the head is shaped so that in the active position of the first element, the rod comes out of the body over a rod length of between 10 and 20 millimeters.

The invention also relates to an instrument comprising a plate and a head as mentioned above attached to the plate.

Optionally the head is temporarily mounted to the plate.

The invention also relates to an installation comprising an instrument as mentioned above as well as means for activating the head.

Other characteristics and advantages of the invention will become apparent on reading the following description of particular non-limiting embodiments of the invention.

The invention will be better understood in the light of the following description with reference to the appended diagrammatic figures, including:

there is a schematic sectional view of an instrument head according to a first embodiment of the invention, when an element of said head is in the inactive position;

there is a schematic sectional view of the head shown in , when the element is in the active position;

there is a schematic sectional view of an instrument head according to a second embodiment of the invention, when the elements of said head are in the inactive position;

there is a schematic sectional view of the head shown in , when the elements are in active position;

there is a schematic perspective view of an instrument head according to a third embodiment of the invention, when the elements of said head are in the inactive position;

there is a schematic perspective view of the head shown in , when the elements are in active position;

there is a schematic sectional view of an instrument head according to a fourth embodiment of the invention, when the elements of said head are in the inactive position;

there is a schematic sectional view of the head shown in , when the elements of said head are in the active position;

there schematically illustrates a variant of preformed rods of the head shown in ;

there is a schematic sectional view of an instrument head according to a fifth embodiment of the invention, when an element of said head is in the inactive position;

there is a schematic sectional view of the head shown in , when the element of said head is in the active position;

there is a schematic sectional view of an instrument head according to a sixth embodiment of the invention, when the elements of said head are in the inactive position;

there is a schematic sectional view of the head shown in , when the elements of said head are in the active position;

there is a schematic sectional view of an instrument head according to a seventh embodiment of the invention, when the elements of said head are in the inactive position;

there is a schematic sectional view of the head shown in , when the elements of said head are in the active position;

there schematically represents an instrument equipped with a head such as the head shown in .

DETAILED DESCRIPTION OF THE INVENTION

A head 1 of a surgical instrument according to a first embodiment of the invention is represented in FIGS. 1a and 1b.

The head 1 here comprises only two elements, namely a single body 2 and a single link 3 movably mounted on the body 2 between an inactive position (illustrated in ) and an active position (shown in ).

In its inactive position, link 3 is in contact with body 2. More precisely, at least one face of link 3 rests against at least one face of body 2. Link 3 thus forms an extension of body 2.

In its active position, the link 3 is on the other hand offset from the body 2 so that the link 3 and the body 2 no longer touch each other.

Optionally, the body 2 like the link 3 are cylinders. In the inactive position, link 3 and body 2 extend coaxially with each other. In the inactive position, a base of link 3 rests against a base of body 2.

In particular, the bases of the body 2 and those of the link 3 externally have the same dimensions. From then on, in the inactive position, link 3 extends in the extension of body 2 without either body 2 or link 3 protruding from each other.

Furthermore, the head 1 is provided with means of relative movement between the body 2 and the link 3, means comprising here a single preformed rod 4. The pre-shaping of the rod 4 can be done by any known means such as for example a heat treatment.

The rod 4 is here in an elastically deformable material and preferably in a super-elastic material.

By "super-elastic material" is meant a material having a very high rate of maximum elastic elongation and typically a rate of maximum elastic elongation of at least 5%.

A maximum rate of elastic elongation is a dimensionless characteristic of materials. It defines the ability of a material to elongate before plastically deforming when stressed in tension i.e. it defines the ability of a material to elongate allowing a return to the initial state without residual plastic deformation. A maximum rate of elastic elongation is thus determined by a tensile test.

The rod 4 is preferably in a shape memory material.

The rod 4 is for example in a steel alloy or even in a nickel-titanium alloy. The nickel-titanium alloy has a maximum elastic elongation rate of about 6%.

The rod 4 is shaped so as to have less rigidity than that of the associated element. For this purpose, one can play on the shape and/or the material of the rod and/or the associated element. In the present case, the body 2, the link 3 and the rod 4 are all made of the same material. However, due to its shape, the rod 4 does indeed have less rigidity than the body 2 or the link 3 (conformed as a block).

In the rest position, that is to say when the rod 4 is outside the head 1 and apart from any external interaction, the rod 4 has a first shape. The rod 4 is here preformed so that in its first shape the rod 4 draws a simple curve. In its first form, the rod 4 therefore forms a bend.

The rod 4 is also arranged in the head 1 so as to extend both in the body 2 and both in the link 3.

To this end, the body 2 is here pierced with a first orifice 5 crossing it right through. Said first orifice 5 thus opens at the level of the two bases of body 2, extending parallel to the central axis of body 2.

Furthermore, the link 3 is here pierced with a first orifice 6 crossing it right through. Said first orifice 6 thus opens at the level of the two bases of the link 3 by extending parallel to the central axis of the link 3. When the link 3 is in the inactive position, the first orifice 5 and the first orifice 6 extend coaxially in continuation of each other.

The rod 4 thus extends in the first orifice 5 of the body 2 on the one hand and in the first orifice 6 of the link 3 on the other hand.

Optionally, the rod 4 is fixed either to the body 2 or to the link 3. In the present case the distal end of the rod 4 is fixed to the link 3 so that the link 3 and the rod 4 are immobile one at a time. 'other. In the present case, only the distal end of rod 4 is arranged in link 3.

This fixation is here permanent. For example, rod 4 is glued and/or welded and/or crimped to link 3.

It is also noted that the proximal end of the rod 4 is always arranged in the body 2 regardless of the relative position between the body 2 and the link 3. Thus the rod 4 and/or the body 2 are provided with means of blocking of the proximal end of the rod 4 in the body 2, said means comprising for example an abutment.

Preferably, the means of relative movement of the link 3 and the body 2 also comprise actuating means which here comprise at least one pin 7 for actuating.

Pin 7 is here shaped as a wire.

Pin 7 is arranged in head 1 so that it extends both into body 2 and into link 3.

To this end, the body 2 is here pierced with a second orifice 8 crossing it right through. Said second orifice 8 thus opens at the level of the two bases of body 2, extending parallel to the central axis of body 2.

Furthermore, the link 3 is here pierced with a second orifice 9, optionally crossing it right through. Said second orifice 9 thus opens at the level of the two bases of the link 3 by extending parallel to the central axis of the link 3. When the link 3 is in the inactive position, the second orifice 9 and the second orifice 8 extend coaxially in continuation of each other.

The pin 7 thus extends in the head by extending into the second orifice 8 on the one hand and into the second orifice 9 on the other hand.

Optionally, the distal end of pin 7 is attached to link 3 so that link 3 and pin 7 are stationary to each other.

This fixation is here permanent. For example pin 7 is glued and/or welded and/or crimped on link 3.

In the present case, the pin 7 passes through the entire body 2 so that the proximal end of the pin 7 extends out of the head 1, the distal end of the pin 7 fixed to the link 3 extending however well inside head 1.

We will now describe the operation of the head 1.

When link 3 is in its inactive position, rod 4 is forced into a second shape which is therefore different from its first shape.

In the present case, in its second form, the rod 4 extends in a rectilinear direction which is coaxial with the direction in which the first orifice 5 of the link and the first orifice 6 of the body extend.

If one wishes to deploy the head 1, one then comes to request the pin 7 so that it moves relative to the body 2. Here one causes a sliding of the pin 7 in the second orifice 8 of the body.

This causes a movement of the link 3 towards its active position but also a movement of the rod 4 vis-à-vis the body 2. In particular, the rod will slide in the first orifice 5 of the body and thus gradually come out of said first hole 5.

Since the rod 4 is then found outside the body 2 and the link 3, it will be able to gradually resume its first shape. The progressive curvature of the rod 4 causes a similar movement of the link 3 vis-à-vis the body 2. The link 3 thus here follows a curved trajectory to move from its inactive position to its active position.

By urging pin 7 in the opposite direction, said pin 7 causes rod 4 to retract into body 2 and allows link 3 to be returned to the inactive position.

Thus, the rod 4 makes it possible to guide the movement of the link 3 vis-à-vis the body 2 and this automatically.

It is noted that the link 3 and the body 2 extend here coaxially with each other only in the inactive position of the link 3. Furthermore the link 3 is always arranged outside the body 2 whatever the relative position between the link 3 and the body 2. Furthermore, in the inactive position of the link 3, the rod 4 is arranged entirely inside the head 1. In the inactive position of the link 3, the majority of the rod 4 is here arranged in body 2.

Referring to Figures 2a and 2b, a second embodiment will now be described.

Head 1 has the same body 2, the same first link 3, the same first pin 7 and the same first rod 4 as what has been described for the first embodiment.

However, the head 1 also has a third element which is here a second link 10 arranged downstream of the first link 3 vis-à-vis the body 2, the first link 3 thus being arranged between the body 2 and the second link 10 .

Optionally the second link 10 and the first link 3 are identical.

In its inactive position, the second link 10 is in contact with the first link 3. More precisely, at least one face of the second link 10 rests against at least one face of the first link 3. The second link 10 thus forms an extension of the first link 3.

In its active position, the second link 10 is on the other hand offset from the first link 3 so that the second link 10 and the first link 3 no longer touch each other.

Optionally, the second link 10 is a cylinder. In the inactive position, the second link 10 extends coaxially with the first link 3. In the inactive position, a base of the first link 3 rests against a base of the second link 10. In particular, the bases of the first link 3 and those of the second link 10 externally have the same dimensions. Therefore in the inactive position, the second link 10 extends in the extension of the first link 3 without either the first link 3 nor the second link 10 protruding from one another.

Furthermore, the head 1 is provided with means of relative movement between the first link 3 and the second link 10, means here comprising a single second rod 11 preformed.

The pre-shaping of the second rod 11 can be done by any known means such as for example a heat treatment.

The second rod 11 is here in an elastically deformable material and preferably in a super-elastic material.

By "super-elastic material" is meant a material having a very high rate of maximum elastic elongation and typically a rate of maximum elastic elongation of at least 5%.

The second rod 11 is preferably made of a shape memory material.

The second rod 11 is for example in a steel alloy or even in a nickel-titanium alloy. The nickel-titanium alloy has a maximum elastic elongation rate of about 6%.

The second rod 11 is shaped so as to have less rigidity than that of the associated element. For this purpose, one can play on the shape and/or the material of the rod and/or the associated element. In the present case, the body 2, the link 3 and the first rod 4 and the second rod 11 are all made of the same material. However, due to its shape, the second rod 11 indeed has less rigidity than the body 2 or the link 3 (conformed as a block).

In the rest position, that is to say when the second rod 11 is outside the head 1 and apart from any external interaction, the second rod 11 has a first shape which here is different from the first shape of the first rod 4. The second rod 11 is here preformed so that in its first shape the second rod 11 draws a simple curve. In its first form, the second rod 11 therefore forms a bend. Said bend here has a reverse curvature with respect to the bend formed by the first rod 4 in its first shape.

The second rod 11 is also arranged in the head 1 so as to extend both in the first link 3 and both in the second link 10.

For this purpose, the second link 10 is here pierced with a first orifice 12 crossing it right through. Said first orifice 12 thus opens at the level of the two bases of the second link 10, extending parallel to the central axis of the second link 10.

When the second link 10 is in the inactive position, the first orifice 12 of the second link 10 and the first orifice 6 of the first link 3 extend coaxially in the extension of one another.

The second rod 11 thus extends in the first orifice 6 of the first link 3 on the one hand and in the first orifice 12 of the second link 10 on the other hand.

Optionally, the second rod 11 is fixed to either the first link 3 or the second link 10. In the present case the distal end of the second rod 11 is fixed to the second link 10 so that the second link 10 and the second rod 11 are motionless to each other.

In the present case, only the distal end of the second rod 11 is arranged in the second link 10.

This fixation is here permanent. For example, the second rod 11 is glued and/or welded and/or crimped to the second link 10.

It is further noted that the proximal end of the second rod 11 is always arranged in the first link 3 regardless of the relative position between the first link 3 and the second link 10. Thus the second rod 11 and/or the first link 3 are provided with means for locking the proximal end of the second rod 11 in the first link 3, said means comprising for example an abutment.

Preferably, the means of relative movement of the second link 10 and the first link 3 comprise actuating means which here comprise at least one second pin 14 for actuating.

The second pin 14 is here shaped as a wire.

The second pin 14 is arranged in the head 1 so as to extend both in the body 2, in the first link 3 and in the second link 10.

For this purpose, the second link 10 is here pierced with a second orifice 15 optionally crossing it right through. Said second orifice 15 thus opens at the level of the two bases of the second link 10 extending parallel to the central axis of the second link 10. When the second link 10 is in the inactive position, the second orifice 15 of the second link and the second orifice 9 of the first link extend coaxially in the extension of one another.

The second pin 14 thus extends into the head by extending into the second hole 15 of the second link, into the second hole 9 of the first link and into the second hole 8 of the body.

Optionally, the distal end of the second pin 14 is fixed to the second link 10 so that the second link 10 and the second pin 14 are fixed to each other.

This fixation is here permanent. For example, the second pin 14 is glued and/or welded and/or crimped onto the second link 10.

In the present case, the second pin 14 passes through the whole body 3 so that the proximal end of the second pin 14 extends out of the head 1, the distal end of the second pin 14 fixed to the second link 10 s extending however well inside the head 1.

We will now describe the operation of the head 1.

When all the links are in their inactive position, the rods 4, 11 are all forced into a second shape which is therefore different from their respective first shape.

In the present case, in their second form, the rods 4, 11 both extend in the same rectilinear direction which is coaxial with the direction in which the first orifice 6 of the first link extends, the first orifice 12 of the second link and the first orifice 5 of the body.

If one wishes to deploy the head 1, one then comes to request the second pin 14 so that it moves relative to the first link 3. Here one causes a sliding of the second pin 14 in the second orifice 9 of the first link and in the second orifice 8 of the body.

This causes a movement of the second link 10 towards its active position but also a movement of the second rod 11 vis-à-vis the first link 3. In particular, the second rod 11 will slide in the first orifice 6 of the first link and thus gradually exit from said first orifice 6.

Because the second rod 11 then finds itself outside the body 2 and the links 3, 10, it will be able to gradually resume its first shape. The progressive curvature of the second rod 11 causes a similar movement of the second link 10 vis-à-vis the first link 3. The second link 10 thus here follows a curved trajectory to move from its inactive position to its active position.

It is noted that the second link 10 and the first link 3 extend coaxially with each other only in the inactive position of the second link 10. Furthermore the second link 10 is always arranged outside the first link 3 regardless of the relative position between the second link 10 and the first link 3. Furthermore, in the inactive position of the second link 10, the second rod 11 is arranged entirely inside the head 1. In the inactive position of the second link 10, the majority of the second rod 11 is here arranged in the first link 3.

By urging the second pin 14 in the opposite direction, said second pin 14 causes the second rod 11 to retract into the first link 3 and allows the second link 10 to be brought back to the inactive position.

Thus, the second rod 11 makes it possible to guide the movement of the second link 10 vis-à-vis the first link 3 and this automatically.

Of course, instead of bringing the second link 10 back to the inactive position, it is also possible to decide to continue the deformation of the head 1 and thus actuate the first pin 7 to cause the relative movement between the first link 3 and the body 2 as which has been described with reference to Figures 1a and 1b.

Of course, it is also possible to decide to first move the first link 3 vis-à-vis the body 2 before moving the second link 10 vis-à-vis the first link 3.

In both cases, the head 1 deforms along an overall trajectory drawing a first path thanks to the first rod 4 and a second path thanks to the second rod 11, an overall trajectory which here is an S.

It is noted that the rods 4, 11 can be preformed so as to have different first shapes or identical first shapes. In this way, playing on the shape of said rods 4, 11, it is possible to print the head 1 more or less complex deployments.

Alternatively or in addition to the first shapes of the rods 4, 11 it is also possible to play on the number of elements of the head 1 as already seen above. For example the number of elements can be increased.

Thus with reference to Figures 3a and 3b, according to a third particular embodiment of the invention, the head 1 comprises five elements, namely four links 21, 22, 23, 24 and a body 20.

The different links 21, 22, 23, 24 are all identical to each other so that when all the links 21, 22, 23, 24 are in their inactive positions (as seen in Figure 1) all the links 21, 22, 23 , 24 extend contiguous to each other and to the body 20.

On the other hand, when all the links 21, 22, 23, 24 are in their active positions, the head 1 follows an overall trajectory defined by the first shapes of the different rods.

A fourth embodiment will now be described with reference to Figures 4a and 4b. This fourth embodiment is identical to the second embodiment except that the actuating means comprise at least two actuating rods to direct the relative movement between the body 2 and the first link 3 and/or comprise at least two actuating rods to direct the relative movement between the first link 3 and the second link 10.

In the present case, the actuating means comprise a first pair 31 of preformed rods to direct the relative movement between the body 2 and the first link 3 and a second pair 32 of preformed rods to direct the relative movement between the first link 3 and the second link 10.

Optionally the body 2 is pierced with a third orifice 33 crossing it right through. Said third orifice 33 thus opens at the level of the two bases of body 2 extending parallel to the central axis of body 2.

Optionally, the first link 3 has a third orifice 34 crossing it right through. Said third orifice 34 thus opens at the level of the two bases of the first link 3 by extending parallel to the central axis of the first link 3. When the first link 3 is in the inactive position, the third orifice 33 of the body and the third orifice 34 of the first link extend coaxially in the extension of one another.

Optionally, the second link 10 includes a third orifice 35 crossing it right through. Said third orifice 35 thus opens out at the two bases of the second link 10 extending parallel to the central axis of the second link 10. When the second link 10 is in the inactive position, the third orifice 35 of the second link and the third orifice 34 of the first link extend coaxially in the extension of one another.

Thus the first rod of the first pair of rods 31 is arranged in the first orifice 5 of the body and the first orifice 6 of the first link and the second rod of the first pair of rods 31 is arranged in the third orifice 33 of the body and the third orifice 34 of the first link.

Similarly, the first rod of the second pair of rods 32 is arranged in the first hole 6 of the first link and the first hole 12 of the second link and the second rod of the second pair of rods 32 is arranged in the third hole 34 of the first link and the third hole 35 of the second link.

The pins 7, 14 also both extend always into the second holes 8, 9, 15 of the body, of the first link and of the second link (for the second pin 14 only for this last element).

Preferably, the second orifices 8, 9, 15 are arranged so as to be framed by the first orifices 5, 6, 12 and the third orifices 33, 34, 35.

The deformation of the head 1 is easier.

For example, each second orifice 8, 9, 15 extends straight along the central axis of the associated element so as to be centered in said element. The first orifices 5, 6, 12 and the third orifices 33, 34, 35 thus extend radially offset from the second orifices 8, 9, 15.

Furthermore, the two rods of the same pair of rods are optionally identical to each other in terms of dimensions and attachment to the associated element.

As illustrated in Figures 4a and 4b, the two rods of the same pair of rods can have the same first shape.

Alternatively as shown in , the two rods of the same pair of rods may have different first shapes or even opposite first shapes.

Figures 5a and 5b illustrate a fifth embodiment which is identical to the first embodiment except that the rod 4 is not fixed to the link 3.

In the present case the rod 4 is movably mounted in the link 3 (in a variant the body 2) according to an axis pivot connection the axis along which the first orifice 6 of the link extends.

Thus, if the rod 4 continues to slide in the first orifice 5 of the body during the deformation of the head 1, it can however pivot relative to the link 3 while imposing a predetermined path on it.

Figures 6a and 6b illustrate a sixth embodiment which is identical to the second embodiment except that at least one of the rods is not fixed to one of the elements (body or link) but is directly attached to the associated pin. In this way the rod and the spindle are immobile vis-à-vis each other.

This fixation is here permanent. For example, the rod is glued and/or welded and/or crimped to the pin.

For example, the rod is fixed to the pin via its distal end.

Preferably, the first rod 4 is fixed to the first pin 7 and the second rod 11 is fixed to the second pin 14. Thus the first pin 7 and the first rod 4 are arranged in the first orifice 5 of the body (for the first pin 7 and the first rod 4) and the first hole 6 of the first link (for the first rod 4 only). And the second pin 14 and the second rod 11 are arranged in the second hole 8 of the body (for the second pin 14 only), the second hole 9 of the first link (for the second pin 14 and the second rod 11) and in the second hole 12 of the second link (for the second rod 11 only).

It is therefore always the displacement of each of the pins which causes the displacement of the rods except that in this sixth embodiment the pins act directly on the rods (unlike the other embodiments and variants described where the pins act on the rods through the links).

A seventh embodiment will now be described with reference to Figures 7a and 7b. This seventh embodiment is identical to the second embodiment except that at least one of the rods extends through three different elements of the head 1 (body and/or links) unlike the other embodiments and variants described for which each rod passed through only two elements. This allows head 1 to have a longer deployment.

Optionally the body 2 is pierced with a third orifice 33 crossing it right through. Said third orifice 33 thus opens at the level of the two bases of body 2, extending parallel to the central axis of body 2.

Optionally, the first link 3 has a third orifice 34 crossing it right through. Said third orifice 34 thus opens at the level of the two bases of the first link 3 by extending parallel to the central axis of the first link 3. When the first link 3 is in the inactive position, the third orifice 33 of the body and the third orifice 34 of the first link extend coaxially in the extension of one another.

Furthermore, the second link 10 is shaped so that when the second link 10 is in the inactive position, the third orifice 34 of the first link and the first orifice 12 of the second link extend coaxially in the extension of one of the other. It is therefore noted that the second link 10 does not have a third orifice even if, as a variant, the second link 10 may comprise such a third orifice. It is also noted that when the second link 10 is in the inactive position the first orifice 12 of the second link does not extend in the extension of the first orifice 6 of the first link as in the other embodiments and variants described.

The first rod 4 is arranged as in the first embodiment by extending into the first orifice 5 of the body and the first orifice 6 of the first link. The first rod 4 is identical to that of the first embodiment.

The second rod 11 is arranged in the head 1 so as to extend both in the body 2, in the first link 3 and in the second link 10. The second rod 11 is therefore longer than the first stem 4.

The second rod 11 thus extends in the head 1 by extending successively in the third orifice 33 of the body, in the third orifice 34 of the first link and finally in the first orifice 12 of the second link.

Optionally, the distal end of the second rod 11 is fixed to the second link 10 so that the second link 10 and the second rod 11 are stationary to each other. In the present case, only the distal end of the second rod 11 is arranged in the second link 10.

This fixation is here permanent. For example, the second rod 11 is glued and/or welded and/or crimped to the second link 10.

It is further noted that the proximal end of the second rod 11 is always arranged in the body 2 regardless of the relative position between the body 2 and the first link 3 and between the first link 3 and the second link 10. Thus the second rod 11 and/or body 2 are provided with means for locking the proximal end of second rod 11 in body 2, said means comprising for example a stop.

The actuating pins also both always extend into the second orifices 8, 9, 15 of the body 2, of the first link 3 and of the second link 10. The actuating pins are identical to those of the first embodiment .

Preferably, the second orifices 8, 9, 15 are arranged so as to be framed by the first orifices 5, 6, 12 and the third orifices 33, 34.

The deformation of the head 1 is easier.

For example, each second orifice 8, 9, 15 extends straight along the central axis of the associated element so as to be centered in said element. The first orifices 5, 6, 12 and the third orifices 33, 34 thus extend radially offset from the second orifices.

With this seventh embodiment, it is noted that the second rod 11 also participates in the movement of the first link 3 vis-à-vis the body 2. This must therefore be taken into account during the pre-shaping of the first rod 4 or of the second rod 11 so that the head 1 indeed follows a targeted overall trajectory. For this purpose, one can rely on different first shapes of the two rods 4, 11 (at least as regards the second rod 11 for its portion which is arranged at the level of the body 2 and the first link 3).

A specific, non-limiting example of application will now be described with reference to the .

The head 1, such as for example that according to the first embodiment of the invention (it being understood that any other head described above could be used for this application) is attached to a plate 100 of an instrument surgical.

For example the body 2 of the head 1 is fixed to said plate 100 so that the plate 100 and the body 2 of the head are immobile with respect to each other.

This fixation is here permanent.

For example, body 2 is glued and/or welded and/or crimped onto plate 100.

The head 1 therefore has a body 2 which is fixed relative to the plate 100 and a single link 3, said link 3 being movable relative to the body 2. For this purpose the head 1 comprises the preformed rod 4 which is fixed to the link 3 and which slides in the body 2.

Typically the instrument is part of an installation comprising means for activating the head and in particular the various spindles (not shown here).

In particular, said means comprise a motor associated directly with a winding crown of the spindle and/or with at least one cable secured to the spindle. As a variant, said means comprise a motor associated with a screw-nut system associated directly with the spindle and/or with a screw-nut system associated with at least one cable integral with the spindle. According to another variant, the activation means comprise another energy conversion device than a motor, such as for example a jack allowing the spindle to be actuated directly and/or allowing a cable attached to the spindle to be actuated.

In this way, by using the energy conversion member, the extension of the spindle is caused and therefore the deployment of the head 1 and vice versa (for example by causing the motor to turn in the other direction or by retracting the rod of the cylinder instead of extending it) it causes the retraction of the spindle and therefore the repositioning of the head 1 where the link is in its inactive position.

The head 1 is thus very simple to deploy or retract.

The plate 100 is optionally a sheath through which pass the spindle and/or the cable secured to the spindle of the head 1 in order to be able to be controlled from outside the instrument by the activation means. Said activation means are therefore arranged outside the head 1 and the instrument and thus are arranged outside the patient during the operation.

As for the head 1, it carries here a first tool, which is a perforation tool 101, as well as a second tool, which here is an optical camera 102. Typically the perforation tool 101 and the optical camera 102 are carried by the free end of head 1 (i.e. the most distal link of said head is link 3 for the particular example illustrated).

The perforation tool actuating cable(s) 101 and/or the optical camera connection cable(s) 102 extend through the head 1 and the platen to be able to be actuated or powered from outside the the instrument and/or extend outside the head 1, along the latter, before passing through the plate 100 in order to be able to be actuated or powered from outside the instrument.

The instrument is here intended to perform a feto-cytoscopy operation.

Thus, the plate 100 here is shaped like a foeto-cystocscope sheath and therefore draws a curve.

In service, the head 1 is already introduced into the bladder to position it at the start of the urethra. Head 1 is then gradually deployed via the actuation pin until it reaches the obstacle. The perforation tool 101 can then be operated by the surgeon.

Thanks to the predetermined conformation of the rod, the head 1 deforms according to the natural curvature of the urethra of the fetus and this automatically.

This makes the operation safer and easier for the surgeon to perform.

A surgical instrument has thus been described comprising a head 1 with a single movable link 3 .

In particular, the link 3 and/or the body 2 has a diameter of between 0.5 and 4 millimeters and preferably between 0.5 and 3.5 millimeters. Preferably, the link and/or the body has a diameter of less than 3 millimeters.

In particular, the rod is preformed so that in its first shape the rod draws a sector curve with an angle between 40 and 80 degrees and preferably between 50 and 70 degrees and preferably 60 degrees.

Furthermore, the head 1 is shaped so that in the active position of the link 3, the rod 4 comes out of the body 2 over a rod length of between 10 and 20 millimeters and preferably between 12 and 18 millimeters and preferably 15 millimeters .

Of course, the invention is not limited to the embodiments and variants described and variant embodiments can be added thereto without departing from the scope of the invention as defined by the claims.

Thus at least one of the elements (body or link) may not have a hole passing through it but only a blind housing in which one of the ends of the rod and/or pin will be arranged.

Although here in the inactive position, the contact between two consecutive elements is made by flat faces, the contact could be made otherwise. For example, the contact could be made by a male-shaped end receiving a female-shaped end. Contact can thus be made by resting a curved portion in a cavity.

It may also be envisaged that in its inactive position the second element penetrates at least partly into the first element.

In the inactive position, the two successive elements may be arranged differently from what has been indicated. For example, the two successive elements may be offset radially relative to each other. We note that the configuration of two consecutive elements in the inactive position of one of the elements is independent of the first shape of the rod connecting them.

Although here the body is the attachment part of the head to the rest of the instrument, the body may be separate from the attachment part and secured to said attachment part.

Although here the different links of the same head are all identical, at least one of the links may be different from the other links. Although here the body is larger than the links, the body may be identical to at least one of the links. Although here each element is shaped like a cylinder, at least one of the elements can be shaped differently, for example by having a section with an ovoid outer shape.

Although here the stem has at least in its central portion (excluding the distal end and the proximal end) a disc section, the stem may be shaped to present another section of the polygon, ring type, etc. The stem may thus be a pipe , a prism…

It will also be possible to make each rod take on a first shape different from what has been indicated and thus a first shape that is more or less complex and of greater or lesser amplitude. The first shape can thus follow a curved path, in S, in zigzag, straight… The path can be in two dimensions, in three dimensions, circular, not circular, rectilinear, not rectilinear… The path can be a curve whose center of curvature is offset with respect to a general axis along which extends an element associated with the rod.

Furthermore, the rod may be prestressed in the head so as to present a second shape which is not rectilinear. Thus in its second form, the rod may be shaped for example in a curve.

As already indicated, the first shape (and/or respectively the second shape) of at least one of the rods can be different or identical to the first shape (and/or respectively the second shape) of at least one other of the rods . For example, if one of the rods forms a first bend in its first shape, the other of the rods may form a second bend with an inverted or identical curvature with respect to the first bend and/or the two bends may be in the same or different planes. For example in the second embodiment, the rods 4 and 11 may have identical first forms of curvature (and not opposite as illustrated in FIGS. 2a and 2b) and/or extending in different planes (and not identical as illustrated). in FIGS. 2a and 2b). The head may comprise anti-rotation means for two elements (link and/or body) between them.

The blocking means may be different from what has been indicated. For example, instead of being arranged on the elements, the blocking means could be arranged on the actuating pins.

Of course, the various embodiments and variants illustrated may be mixed together. Thus for any embodiments and variants described the number of elements may be different provided that the head comprises at least two. The pivot assembly of the fifth embodiment could be applied for example to the fourth embodiment or to the seventh embodiment. The sixth embodiment and the seventh embodiment may be combined with one another and/or applied to a variant or embodiment where at least one pair of elements is actuated by only one rod. Etc.

Although here the plate is distinct from the head, the plate and the head can be one and the same part.

Although here the head is permanently fixed to the plate of the instrument, the head and the plate can be provided with their means of temporary fixing. Thus the head can be disconnected from the plate when the intervention is completed in order to apply another head to the plate (presenting a different deformation than the initial head) and thus will allow the installation to be able to intervene on another zone of the body and/or on another patient. The temporary fastening means can provide temporary fastening, for example by clipping, screwing, etc.

The whole head can be disconnected from the plate or only part of the head. For example, the actuating pins can remain in place in the instrument despite the disconnection of the head in order to be able to be used with another head. Thus, although here the actuating pins are permanently attached to the head, the actuating pins can be temporarily attached to the head, for example by clipping, screwing, etc.

The instrument may have more or fewer tools than indicated. The tool may be carried by an element of the head other than the most distal element, such as for example one of the actuating pins. The tool may not be carried directly by the head: the head may thus be shaped to allow the tool to pass through it and/or along it.

The tool may be different from what has been indicated and be, for example, a camera, a probe, a needle holder, pliers, a lighting device, etc.

The instrument can thus be at least a navigation and/or exploration instrument. Optionally, the instrument may be at least one endoscope.

The instrument can be used in many other applications than what has been indicated. The instrument will thus be able to provide access to the olfactory cells of the nose, to the internal ducts of the ears, to the heart, to the brain, to the urinary system of an infant, a child or an adult, to make it possible to carry out antenatal surgery, neurosurgery, etc. The instrument can be used to act on an organ or only to observe it. The instrument can be introduced into the human body through a channel (natural or artificial), through the skin, etc.

For example, the instrument can be used for embolization of an aneurysm by dropping an embolization spring (or "coil") at the level of the aneurysm. For example, the instrument can be used in the case of a fetal-fetal transfusion syndrome in twins to grill the anastomoses with a laser so that each fetus has its own placenta pouch.

The head can be, if desired, specific to a single patient. To this end, from at least one medical imaging examination previously carried out (such as a scanner, an MRI, an X-ray, etc.), we can reconstruct in three dimensions a zone of the patient on which we wish to intervene and deduce which first shape it will be necessary to give to one or more rods to direct the head towards the targeted area. As a replacement, the head can be manufactured not specifically for a patient but in a dedicated way for a panel (of a given patient, of a given age of the pathology, etc.).

Although here the installation is a surgical installation, the instrument a surgical instrument and the head a surgical head, the head, the instrument and the installation can be used in any other field such as for example in a context of non-destructive testing, in the mechanical field, the nuclear field… the body into which the head is inserted is therefore not necessarily human. By way of non-limiting example, the head (and therefore the instrument and the installation) can be used in a non-destructive testing framework in an aircraft engine.

Claims (19)

Instrument head comprising a first element and at least one second element movably mounted on the first element between an inactive position and an active position, the head thus being provided with means for relative displacement of the second element vis-à-vis the first element , said means comprising at least one preformed rod (4, 11) having a first shape when the rod is outside the head in the rest state, the rod being arranged in the head so as to extend both in the first element and both in the second element so that in the inactive position of the second element, the rod is forced into a second shape different from the first shape, the rod thus gradually returning to its first shape when the second element moves towards its active position. Head according to claim 1, comprising at least a third element mounted so as to move on the second element between an inactive position and an active position, the relative displacement means comprising at least a second preformed rod (4, 11) presenting a first shape when the second rod is outside the head in the rest state, the second rod being arranged in the head so as to extend at least into the second element and the third element so that in the inactive position of the third element, the second rod is forced into a second shape different from the first shape of the second rod, the second rod thus gradually returning to its first shape when the third element moves towards its active position. Head according to claim 2, in which the second rod also extends into the first element. Head according to one of the preceding claims, comprising at least one additional rod (31, 32) also making it possible to ensure the relative movement of the second element with respect to the first element. Head according to claim 4, in which the first rod and the second rod making it possible to ensure the relative displacement of the second element vis-à-vis the first element have different first shapes. Head according to one of the preceding claims, in which the rod (4, 11) is fixed to the first element or to the second element. Head according to one of the preceding claims, in which in the inactive position of the second element, the first element and the second element are in contact with each other. Head according to one of the preceding claims, in which in the inactive position of the second element, the first element and the second element extend coaxially with respect to each other. Head according to one of the preceding claims, in which the first element and the second element have a cross section of the same shape and/or of the same dimensions. Head according to one of the preceding claims, in which in the inactive position of the second element, the rod (4, 11) is arranged entirely inside the head. Head according to one of the preceding claims, in which the rod (4, 11) is preformed so as to be curved in its first shape. Head according to one of the preceding claims, in which the relative displacement means also comprise actuation means which comprise at least one actuation pin. Head according to Claim 12, in which the rod (4, 11) is fixed to the said pin (7, 14). Head according to one of the preceding claims, in which at least one of the elements has a diameter of less than 3 millimeters. Head according to one of the preceding claims, in which the rod (4) is preformed so that in its first shape the rod draws a sector curve with an angle of between 40 and 80 degrees. Head according to one of the preceding claims, shaped so that in the active position of the first element, the rod (4) comes out of the body (2) over a rod length of between 10 and 20 millimetres. Instrument comprising a plate (100) and a head (1) according to one of the preceding claims, the head being attached to the plate. Instrument according to the preceding claim, in which the head (1) is temporarily mounted on the plate (100). Installation comprising an instrument according to one of the preceding claims as well as means for activating the head (1).