Patent Description:
Surgical instruments used for minimally invasive surgery such as laparoscopic surgery require a high degree of freedom in the head section attached to the distal end of the surgical instrument. Since it is necessary for a surgeon operating a surgery of a patient (surgical subject) to grip the surgical instrument that is partially inserted into the body while manipulating the head portion, such a surgical instrument must be the one capable of being easily manipulated by the surgeon's hand while achieving fine head movements.

To achieve fine head movements, the surgical instrument is required to reliably transmit, by a simple hand manipulation, the movement from the manipulating side (proximal side near the surgeon) to the side where the head portion is positioned (distal side apart from the surgeon).

The invention described in Patent Literature <NUM> relates to a surgical instrument used in laparoscopic surgery or the like. The surgical instrument is roughly configured of, in the order from distal end side; a tool head, a central system, a main body portion, and a proximal handle. <CIT> and <CIT> disclose similar devices of the prior art. [Other Prior Art Documents].

Claim <NUM> defines the invention and dependent claims disclose embodiments. No surgical methods are claimed.

With the surgical instrument described in PTL <NUM>, the tool head at the distal end can move freely in lateral direction by a hand manipulation of a surgeon, and the body tissue can be dissected if, for example, the tool head has a function of scissors.

In the surgical instrument described in PTL <NUM>, the function to convert the surgeon's hand manipulation into a movement of a tool head primarily relies on the central system <NUM>. To assemble the central system <NUM>, numerous components are required, including a third outer shaft 3a, a second intermediate shaft 3b, a center rod 3c, a universal joint 3d, a rigid slider 3e, a cylinder 3f, a rear rotating collar <NUM>, rigid links <NUM> and 3i, a front cover 2a, a rigid tubular rod 2b, a front rotating collar 2c, and so on.

Since a surgical instrument is used in an area very close to the surgical field inside the patient's body, and is used for surgery that must be performed within a limited time, such a surgical instrument should never cause any failure during surgery and thus is required to be robust. If any component of the surgical instrument falls into the surgical field, the component must be positioned and removed, which can be a major problem. There is thus contradictory between the ability to freely move the tool head at the distal end and the safety assurance required for such a surgical instrument.

The present invention is made in consideration of the above respect, and the object is to provide a surgical instrument used for minimally invasive surgery such as laparoscopic surgery, in which the head can be freely moved by a simple hand manipulation by a surgeon, and in which the number of components is reduced to ensure high safety.

Thepresent disclosure relating to the present invention made to solve the above-mentioned problem, is a surgical instrument comprising: at a distal portion, a tool head having longitudinal and lateral degrees of freedom; and at a proximal portion, a first manipulator to control the longitudinal degrees of freedom and a second manipulator to control the lateral degrees of freedom; wherein: the tool head includes a movable portion having longitudinal degrees of freedom and a base portion that defines a lateral orientation of the tool head; the movable portion and the first manipulator are connected by a first connecting structure; the base portion and the second manipulator are connected by a second connecting structure; the first connecting structure includes a first conversion mechanism that converts linear motion from the first manipulator to rotational motion, a first shaft that is to be rotated by the first conversion mechanism, a universal joint provided at a distal end portion of the first shaft, a second conversion mechanism connected to the universal joint to convert rotational motion into linear motion, and a crank provided at a distal end portion of the second connecting structure and connected to a proximal end portion of the movable portion; the second conversion mechanism transmits rotational motion of the second manipulator, provided with a tubular shaft in which the first shaft is coaxially encompassed and a pinion is formed at the distal portion, and a rack base portion being linked to the base portion where a rack to be meshed with the pinion being formed thereon in an approximate semi-circular shape; and an intersection of shaft centers of two pivot shafts of the universal joint is positioned on an axial center of rotational axis of the rack.

The surgical instrument has two manipulators, the first manipulator and the second manipulator, which are the manipulators to be manipulated by a surgeon. The first manipulator is for moving the movable portion in a longitudinal direction, and the second manipulator is for moving the base portion in a lateral direction.

There provided the first connecting structure for connecting the first manipulator and the tool head and the second connecting structure for connecting the second manipulator and the tool head. The first connecting structure includes: the first conversion mechanism that converts linear motion from the first manipulator to rotational motion; the first shaft that is to be rotated by the first conversion mechanism, the universal joint provided at the distal end portion of the first shaft; the second conversion mechanism connected to the universal joint to convert rotational motion into linear motion; and the crank provided at the distal end portion of the second conversion mechanism and connected to the proximal end portion of the movable portion. This first connecting structure transmits the manipulation from the first manipulator to the tool head.

The second connecting structure is configured to transmit rotational motion from the second manipulator, the second connecting structure including: a tubular shaft coaxially encompassing the first shaft and having a pinion formed at the distal portion, and a rack base portion where a rack to be meshed with the pinion is formed thereon in an approximate semi-circular shape. This second connecting structure transmits the manipulation from the second manipulator to the tool head.

Since the intersection of shaft centers of two pivot shafts of the universal joint is positioned on an axial center of rotational axis of the rack, even when the orientation of the base portion linked to the rack base portion is changed laterally to a certain angle by the manipulation from the second manipulator, the movable portion also moves laterally in the same angle, and further, the movable potion can be oriented in a longitudinal direction by the manipulation from the first manipulator. With this structure, it is possible to provide a surgical instrument in which the tool head can be freely moved by a simple hand manipulation, and in which the number of components is reduced to ensure high safety.

The surgical instrument of the present disclosure is characterized in that: the first conversion mechanism includes a first tubular body in which the first shaft penetrates therethrough; a first helical groove is formed on a side wall of the first tubular body; a first slide element that is to be guided by the first helical groove to slide is formed on the first shaft; on the outer surface of the first tubular body, a first tubular body engaging portion that engages with the first manipulator to transmit linear motion from the first manipulator to the first tubular body is formed; and when the first manipulator is moved, the first tubular body moves linearly, and the first slide element is guided by the first helical groove, which allows the first shaft to rotate.

Since the linear motion of the first manipulator is converted to the rotary motion of the first shaft by a combination of the first tubular body on which the first helical groove is formed and the first shaft having the first slide element, the first shaft can be rotated by the motion from the first manipulator with the simple structure.

This surgical instrument of the present disclosure is characterized in that: the second conversion mechanism includes a second tubular body that is rotated in connection with the universal joint; on the side surface of the second tubular body, a second helical groove is formed and a second shaft connected to the proximal end of the crank is provided; a second slide element to be guided to slide by the second helical groove is formed on the second shaft; and when the second tubular body is rotated, the second slide element is guided by the second helical groove, which allows the second shaft to perform liner motion.

Since the combination of the second tubular body on which the second helical groove is formed and the second shaft having the second slide element enables to convert the rotary motion of the first shaft into the linear motion of the second shaft, with the simple structure, the second shaft can be linearly moved by the movement of the first manipulator, the movement of which is transmitted to the crankshaft so as to allow the movable portion to move.

The surgical instrument according to any of the present disclosure, comprising a function of forceps to grip a living tissue, by means of the movable portion and the base portion of the tool head.

The surgical instrument according to the present disclosure is applicable to surgical instruments imparted with various functions. The present disclosure is one of such instruments. The tool head is imparted with the function of a so-called bioptome. By simply forming the shape of the movable portion and the shape of the base portion of the tool head so as to be suitable for gripping a part of the body tissue, it is possible to impart a safe and flexible bioptome function.

The surgical instrument according to any of the present disclosure, provided with a function of scissors for cutting living tissue, by means of the movable portion and the base portion of the tool head.

The disclosure is a surgical instrument in which the tool head is imparted with a so-called a function of scissors. By simply forming the shape of the movable portion and the shape of the base portion of the tool head so as to be suitable for cutting parts of the body tissue, it is possible to impart a safe and flexible function of scissors.

The surgical instrument according to any of the disclosure, provided with an endoscopic function, wherein a camera is mounted on the movable portion of the tool head for internally inspecting the body.

With a camera being mounted at the movable portion of the tool head, the surgical instrument of the present disclosure can play a role of an endoscope that can be freely oriented in both lateral and longitudinal directions.

According to the present invention, it is possible to provide a surgical instrument used for minimally invasive surgery such as laparoscopic surgery, in which the head can be freely moved by a simple hand manipulation by a surgeon, and in which the number of components is reduced to ensure high safety.

Embodiments of the present disclosure will be hereinafter described by referring to the drawings. It should be noted that the following embodiments are illustrative examples that are preferred in nature and are not intended to limit the scope of the invention, its applications, or uses.

<FIG> is a perspective diagram of the surgical instrument <NUM> according to Embodiment <NUM> of the present invention provided with a function of bioptome, there illustrated a first manipulator <NUM> and a second manipulator <NUM>, a tool head <NUM> and a cover <NUM> that encompasses a member for linking both manipulators <NUM> and <NUM> to the tool head <NUM>. Holes <NUM> drilled in the cover <NUM> are provided for facilitating post-operative cleaning.

The first manipulator <NUM> is formed in a handle type, composed of a manipulation movable portion <NUM>, a plate spring <NUM>, and a manipulation fixing portion <NUM>, but the form of the first manipulator <NUM> is not limited to this type. A first conversion mechanism 40A is shown above the first manipulator <NUM>. The first conversion mechanism 40A is configured such that a first shaft <NUM> is rotated by the movement of a first tubular body <NUM>, which is linked to the movement of the first manipulator <NUM> via a first tubular body engaging portion <NUM>. A first helical groove <NUM> plays a role to convert this linear motion into rotary motion, which mechanism will be explained in detail in the description of <FIG>. The tool head <NUM> is provided with a base portion <NUM> of the tool head <NUM> to be oriented in the lateral direction with respect to the axial direction of the cover <NUM>, and a movable portion <NUM> of the tool head <NUM> to be oriented in the longitudinal direction with respect to the axial direction of the cover <NUM>.

<FIG> shows the surgical instrument <NUM> of <FIG> in a state where the cover <NUM> is removed. A first connected structure 50A illustrated in <FIG> is a connected structure that connects the first manipulator <NUM> and the movable portion <NUM> of the tool head <NUM>. A second connected structure 50B is a connected structure that connects the second manipulator <NUM> and the base portion <NUM> of the tool head <NUM>. A tubular shaft <NUM> is configured to transmit the rotation of the second manipulator <NUM> directly as rotary motion to a pinion <NUM> at the distal end. The pinion <NUM> meshes with a rack <NUM> arranged on a rack base portion <NUM> so as to allow the rack base portion <NUM> to rotate. The rack base portion <NUM> is directly connected to the base portion <NUM> of the tool head <NUM>, thereby the base portion <NUM> is commensurately rotated. The tubular shaft <NUM> is provided with multiple longitudinal grooves <NUM>, which are designed to facilitate the cleaning of the instrument after surgery. A second manipulator-rotation stopper <NUM> shown in the drawing is a member for preventing the second manipulator <NUM> from rotating inadvertently, after the completion of intended manipulation performed by rotating the second manipulator <NUM>.

<FIG> is a perspective diagram illustrating the enlarged view of a portion of the first conversion mechanism 40A of the medical instrument of Embodiment <NUM>. An engaging recess <NUM> formed in the upper part of the manipulation movable portion <NUM> and a first tubular body engaging portion <NUM> attached on the outer surface of the first tubular body <NUM> are engaged with each other, thereby the movement of the first manipulator <NUM> is transmitted to the first tubular body <NUM>, which allows the first tubular body <NUM> to move forward and backward. Along with the above-mentioned movements, a first slide element <NUM> formed on the first shaft <NUM> is moved along the first helical groove <NUM>, which allows the first shaft <NUM> to rotate.

The movement of the second conversion mechanism 40B will be explained with reference to <FIG>. A universal joint <NUM> is attached at the distal end of the first shaft <NUM>. The universal joint <NUM> is provided with a first bifurcated piece <NUM>, an intermediate body <NUM>, a first pivot shaft <NUM> and a second pivot shaft <NUM>. A second tubular body <NUM> at the distal end side is encompassed in an outer tube <NUM> (see <FIG>), and the outer tube <NUM> is provided with a second bifurcated piece <NUM> (see <FIG>) to be linked to the second pivot shaft <NUM>. Protrusions <NUM> are for connecting the second tubular body <NUM> and the outer tube <NUM>, but since <FIG>. illustrates the state where the outer tube <NUM> is removed, the first shaft <NUM> and the tool head <NUM> are not yet connected. There are two protrusions <NUM> on top and bottom, but the protrusions may be formed of a single bar body.

A second helical groove <NUM> is cut in the second tubular body <NUM>, and a second slide element <NUM> attached to the second shaft <NUM> that is connected to a proximal end 80a of a crank <NUM> is guided along the second helical groove <NUM> to move forward and backward in association with the rotation of the second tubular body <NUM>. The forward and backward movements are transmitted to the crank <NUM>, which cause a change in longitudinal orientation of the movable portion <NUM> of the crank <NUM>.

<FIG> illustrates a state where the outer tube <NUM> is mounted, with the second bifurcated piece <NUM> being connected to the second pivot shaft <NUM>. <FIG> shows a state where the movable portion <NUM> is opened, in a state where the second slide element <NUM> is moved to the most proximal side (right side in the drawing). In contrast, <FIG> shows a state where the movable portion <NUM> is closed, in a state where the second slide element <NUM> is moved to the most distal side (left side in the drawing). This state is the same as shown in <FIG>.

<FIG> schematically shows the movement of the crank <NUM>. <FIG> shows a state where the second slide element <NUM> is moved to the most proximal side. An L-shaped body <NUM> is composed of an L-shaped body first portion 82a and an L-shaped body second portion 82b, and the L-shaped body first portion 82a corresponds to the movable portion <NUM> of the tool head <NUM>. The second shaft <NUM> is connected to the proximal end portion of the L-shaped second portion 82b by an arm <NUM>, and the second shaft and arm <NUM> are connected pivotably about a first axis <NUM>. The arm <NUM> and the L-shaped second portion 82b are connected pivotably about a second axis <NUM>. A third shaft <NUM> is provided for allowing the L-shaped body <NUM> to pivot thereabout as a pivot shaft.

<FIG> shows that the second slide element <NUM> is moved from the position shown in <FIG> to a position at the most distal end side by the rotation of the first shaft <NUM>. When comparing <FIG>, the second slide element <NUM> moves from the dotted position P<NUM> to the dotted position P<NUM> by the distance indicated with an arrow, and by the same distance of which, the second shaft <NUM> axially displaced. The second shaft <NUM> is moved to the distal side and the arm <NUM> is vertically oriented, and the L-shaped body <NUM> (the movable portion <NUM> of the tool head <NUM>) is displaced so as to allow the L-shaped body first portion 82a to be horizontal oriented. A position P<NUM> of the third axis <NUM> is configured to be fixed.

<FIG> is a diagram illustrating the movement of the present surgical instrument <NUM> in a state where the first conversion structure 50A and the second conversion structure 50B are combined. When the second manipulator <NUM> is rotated by hand, the pinion <NUM> mounted on the distal end of the tubular shaft <NUM> is rotated while being meshed with the rack <NUM> formed in an approximate semi-circular shape on the rack base portion <NUM> so that the rack base portion <NUM> is rotated, and since the rack base portion <NUM> and the base portion <NUM> of the tool head <NUM> are connected, the orientation of the base portion <NUM> is changed.

This manipulation causes the universal joint <NUM> to change the orientation of the movable portion <NUM> about the first pivot shaft <NUM> by the same angle as that of the base portion <NUM>. The above is enabled by the configuration such that the intersection of the shaft centers of the first pivot shaft <NUM> and the second pivot shaft <NUM> are positioned on the axial center of the rotational axis of the rack base portion <NUM>. With the above configuration, in commensuration with the movement of the base portion <NUM>, which is rotated by the same angle as the rotation of the rack base portion <NUM>, the movable portion <NUM> is rotated by the same angle, thereby the first conversion mechanism 40A allows the movable portion <NUM> to move longitudinally.

<FIG> is a perspective diagram illustrating the second connecting structure 50B when viewed from the proximal side.

<FIG> is a perspective diagram illustrating the distal end portion of the surgical instrument <NUM> provided with a function of forceps to grip the biological tissue. The movable portion <NUM> is an upper gripping portion 31a and the base portion <NUM> is a lower gripping portion 32a. By variously modifying the form of the distal end portion as mentioned above, it is possible to provide a surgical instrument with a function of scissors, or a surgical instrument with a function of endoscope, equipped with a camera for internally inspecting the body.

Claim 1:
A surgical instrument comprising:
at a distal portion, a tool head (<NUM>) having longitudinal and lateral degrees of freedom; and at a proximal portion, a first manipulator (<NUM>) to control the longitudinal degrees of freedom and a second manipulator (<NUM>) to control the lateral degrees of freedom; wherein
the tool head includes a movable portion (<NUM>) having longitudinal degrees of freedom and a base portion (<NUM>) that defines a lateral orientation of the tool head,
the movable portion and the first manipulator are connected by a first connecting structure,
the base portion and the second manipulator are connected by a second connecting structure,
the first connecting structure includes: a first conversion mechanism (40A) that converts linear motion from the first manipulator to rotational motion; a first shaft (<NUM>) that is to be rotated by the first conversion mechanism; a universal joint (<NUM>) provided at a distal end portion of the first shaft; a second conversion mechanism (40B) that is connected to the universal joint to convert rotational motion into linear motion; and a crank (<NUM>) provided at a distal end portion of the second conversion mechanism and connected to a proximal end portion of the movable portion;
the second connecting structure is configured to transmit rotational motion of the second manipulator, and provided with: a tubular shaft (<NUM>) in which the first shaft is coaxially encompassed and a pinion (<NUM>) is formed at a distal portion; and a rack base portion (<NUM>) being linked to the base portion, on which a rack to be meshed with the pinion is formed in an approximate semi-circular shape;
and an intersection of shaft centers of two pivot shafts (<NUM>,<NUM>) of the universal joint is positioned on an axial center of rotational axis of the rack.