Patent Description:
It especially relates to a cutting instrument comprising:.

Such a cutting instrument is already known from <CIT>. Further state of the art can be derived from <CIT>, <CIT>, <CIT>, <CIT>, mid <CIT>, <CIT>, <CIT> and <CIT>.

In many situations, tissue may need to be accessed at a remote surgical site, excised from the adjacent anatomy and then the excised tissue removed from the remote surgical site. By way of example but not limitation, during arthroscopic surgery, endoscopic surgery, ENT surgery, etc., relatively small visualization devices (e.g., "scopes") and relatively small surgical tools (e.g., graspers, cutters, cauterizers, etc.) are generally introduced into a restricted space within the human body (e.g., the interior of a joint, the interior of the abdomen, the interior of a nasal passage, etc.) and then used at that location for a specific surgical procedure (e.g., to trim meniscal cartilage in a joint, to excise a tissue mass in the abdomen, to excise a tissue mass in a nasal passage, etc.). In many such surgeries, fluid is introduced into the surgical site (and thereafter removed from the surgical site) so as to distend the anatomy for better access and/or visualization (e.g., so as to distend the knee joint for better access and/or visualization), and/or to improve visibility (e.g., so as to flush away blood), and/or to remove debris (e.g., so as to remove severed tissue by suction).

One of the surgical tools frequently employed in such surgeries is the so-called "powered shaver".

Powered shavers typically comprise an outer tube having a window, and an inner tube rotatably disposed within the outer tube and having an opening, wherein rotation of the inner tube within the outer tube causes the opening of the inner tube to repetitively sweep across the window of the outer tube, whereby to shear off tissue extending into the window of the outer tube. Suction is applied to the interior of the inner tube so as to remove the tissue sheared off by the powered shaver. See, for example, <CIT>. ) and <CIT>.

Unfortunately, current powered shavers tend to suffer from one or more disadvantages. By way of example but not limitation, current powered shavers tend to suffer from small window sizes, which is generally the result of efforts to ensure adequate suction in order to remove sizable debris through the interior of the inner tube. In addition, current powered shavers tend to suffer from inefficient cutting action, which is generally the result of the shearing geometries employed. Among other things, with current powered shavers, the oscillating motion and location of the cutting surfaces tend to "bat" tissue around, in a side-to-side motion. Furthermore, current powered shavers tend to suffer from poor suction, which is generally the result of the geometries used for the window of the outer tube and the opening in the inner tube.

Thus it would be advantageous to provide a new powered cutter which improves upon the deficiencies of the prior art. Among other things, it would be advantageous to provide a new powered cutter which provides enlarged window sizes, improved cutting action and superior suction.

The present invention comprises the provision of a new powered cutter which improves upon the deficiencies of the prior art. Among other things, the new powered cutter provides enlarged window sizes, improved cutting action and superior suction.

The invention is defined by independent claim <NUM>, with further embodiments disclosed in the dependent claims.

In one form of the disclosure, there is provided a cutting instrument comprising:.

In another form of the disclosure, there is provided a cutting instrument comprising:.

There is also provided a method for cutting an object, which is not according to the invention and is present for illustration purposes only, the method comprising :
providing a cutting instrument comprising:.

In another form of the disclosure, there is provided a method for cutting an object, the method comprising :.

wherein said at least one canted edge of said opening and said at least one canted edge of said window are canted in the same direction of turn;
positioning the object in said window; and rotating said inner tube within said outer tube.

Methods for cutting of tissue and the use of the cutter are not part of the claimed invention and only for illustration purposes.

These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:.

The present invention comprises the provision of a new powered cutter which improves upon the deficiencies of the prior art. Among other things, this new powered cutter provides enlarged window sizes, improved cutting action and superior suction.

More particularly, and looking now at <FIG>, there is shown a novel powered cutter <NUM> formed in accordance with the present invention. Novel powered cutter <NUM> generally comprises a blade assembly <NUM> and a handle assembly <NUM>. As will hereinafter be discussed in further detail, blade assembly <NUM> is intended to be mated to handle assembly <NUM> (or another handle assembly) at the time of use, and detached from handle assembly <NUM> (or another handle assembly) after use (e.g., for cleaning and sterilization, repair or replacement, etc.). Alternatively, blade assembly <NUM> may be mated to handle assembly <NUM> (or another handle assembly) at the time of manufacture, e.g., such as in the case of a one-piece disposable system.

Blade assembly <NUM> is shown in greater detail in <FIG>. Blade assembly <NUM> generally comprises an outer tube <NUM> and inner tube <NUM> rotatably disposed within outer tube <NUM>.

Outer tube <NUM> is shown in greater detail in <FIG>. Outer tube <NUM> generally comprises a distal end <NUM>, a proximal end <NUM>, and a lumen <NUM> extending from distal end <NUM> to proximal end <NUM>. In one preferred form the present invention, outer tube <NUM> preferably comprises a closed distal end <NUM>.

Outer tube <NUM> comprises a window <NUM> comprising a leading edge <NUM> and a trailing edge <NUM>. In one preferred form of the invention, leading edge <NUM> and trailing edge <NUM> are canted relative to the longitudinal axis <NUM> of outer tube <NUM>. According to the invention, leading edge <NUM> and trailing edge <NUM> have a helical configuration (which may be of constant pitch or non-constant pitch). In one preferred form of the present invention, outer tube <NUM> also comprises a first edge <NUM> connecting leading edge <NUM> to trailing edge <NUM>, and a second edge <NUM> connecting leading edge <NUM> to trailing edge <NUM>. Inner tube <NUM> is shown in greater detail in <FIG> and <FIG>. Inner tube <NUM> generally comprises a distal end <NUM>, a proximal end <NUM>, and a lumen <NUM> extending from distal end <NUM> to proximal end <NUM>. In one preferred form of the present invention, inner tube <NUM> preferably comprises a closed distal end <NUM>.

Inner tube <NUM> comprises an opening <NUM> comprising a leading edge <NUM> and a trailing edge <NUM>. In one preferred form of the invention, leading edge <NUM> and trailing edge <NUM> are canted relative to the longitudinal axis <NUM> of inner tube <NUM>. In the invention, leading edge <NUM> and trailing edge <NUM> have a helical configuration (which may be of constant pitch or non-constant pitch).

It should be appreciated that leading edge <NUM> of inner tube <NUM> extends at an angle to trailing edge <NUM> of outer tube <NUM>, and/or trailing edge <NUM> of inner tube <NUM> extends at an angle to leading edge <NUM> of outer tube <NUM>, so as to create a shearing action between such surfaces (i.e., edges) when inner tube <NUM> is rotated relative to outer tube <NUM>, as will hereinafter be discussed.

Inner tube <NUM> is rotatably disposed within outer tube <NUM> such that rotation of inner tube <NUM> within outer tube <NUM> causes opening <NUM> of inner tube <NUM> to repetitively sweep across window <NUM> of outer tube <NUM>, whereby to shear off tissue extending into window <NUM> of outer tube <NUM>. More particularly, in accordance with the present invention, as inner tube <NUM> is rotated within outer tube <NUM>, leading edge <NUM> of inner tube <NUM> is swept across trailing edge <NUM> of outer tube <NUM> or, depending on the direction of rotation of inner tube <NUM> relative to outer tube <NUM>, trailing edge <NUM> of inner tube <NUM> is swept across leading edge <NUM> of outer tube <NUM>, so as to create a shearing action at the interface of leading edge <NUM> of inner tube <NUM> and trailing edge <NUM> of outer tube <NUM>, or at the interface of trailing edge <NUM> of inner tube <NUM> and leading edge <NUM> of outer tube <NUM>. This shearing action serves to cut away tissue extending into window <NUM> of outer tube <NUM>. It should be appreciated that this shearing action is superior to the cutting action of conventional powered cutters due to the moving point contact of the shearing ("scissoring") surfaces (i.e., edges). In addition, this shearing action is superior to the cutting action of conventional powered cutters, inasmuch as the cutting forces of novel powered cutter <NUM> are generally directed proximally or distally, rather than laterally (as is the case where the side edges of windows are used for cutting). Directing the cutting forces proximally or distally, rather than laterally, can help the surgeon keep the powered cutter in the desired position and also help keep tissue from being "batted" around, in a side-to-side motion, during cutting. Suction applied to lumen <NUM> of inner tube <NUM> removes the excised tissue from blade assembly <NUM>.

If desired, space can be provided between inner tube <NUM> and outer tube <NUM> so as to allow irrigation to be supplied to the surgical site. In one preferred form of the invention, inner tube <NUM> is configured to completely block window <NUM> of outer tube <NUM> during a phase of the rotation of inner tube <NUM> within outer tube <NUM>. As a result, larger window sizes can be used while still providing superior suction for the blade assembly.

In one preferred form of the invention, and looking now at <FIG> and IOC, blade assembly <NUM> can be considered to assume three different "states" as inner tube <NUM> rotates within outer tube <NUM>, i.e., a "window fully open" state (<FIG>) where suction is used to facilitate tissue engagement, a "resecting" state (<FIG>) where the surfaces (i.e., edges) of inner tube <NUM> and outer tube <NUM> cooperate to provide a scissoring action so as to cut tissue extending into window <NUM> of outer tube <NUM>, and a "window fully closed" state (Fig. IOC) where inner tube <NUM> substantially completely closes off window <NUM> of outer tube <NUM>, thereby allowing for maximum inner lumen suction to rid the cutting area of tissue and fluid. As shown in <FIG>, blade assembly <NUM> is intended to be mated to handle assembly <NUM> (or another handle assembly) at the time of use, and detached from handle assembly <NUM> (or another handle assembly) after use (e.g., for cleaning and sterilization, repair or replacement, etc.). Alternatively, blade assembly <NUM> may be mated to handle assembly <NUM> (or another handle assembly) at the time of manufacture, e.g., such as in the case of a one-piece disposable system. Handle assembly <NUM> is provided with a housing <NUM> for securely mounting the distal end <NUM> of outer tube <NUM>, and means for coupling a drive shaft <NUM> to inner tube <NUM>, e.g., a connector <NUM> which is secured to drive shaft <NUM> and inner tube <NUM>. Preferably connector <NUM> is provided with appropriate ports so that the interior of inner tube <NUM> is in fluid communication with a suction port <NUM>, whereby to provide suction to blade assembly <NUM>.

It should be appreciated that handle assembly <NUM> shown in <FIG> is provided by way of example but not limitation, and other handle assemblies may be used in conjunction with blade assembly <NUM>.

<FIG> show alternative configurations for outer tube <NUM> and its window <NUM>.

More particularly, in <FIG>, window <NUM> is constructed so that its leading edge <NUM> extends perpendicular to the longitudinal axis of outer tube <NUM> and its trailing edge <NUM> is canted relative to the longitudinal axis <NUM> of outer tube <NUM>, with first edge <NUM> and second edge <NUM> extending between leading edge <NUM> and trailing edge <NUM>.

In <FIG>, window <NUM> is constructed so that its leading edge <NUM> and its first edge <NUM> and second edge <NUM> combine to form an arcuate surface (i.e., edge), and its trailing edge <NUM> is canted relative to the longitudinal axis <NUM> of outer tube <NUM>.

In <FIG>, window <NUM> is constructed so that its leading edge <NUM> and its first edge <NUM> combine to form an arcuate surface (i.e., edge), its trailing edge <NUM> is canted relative to the longitudinal axis <NUM> of outer tube <NUM>, and its second edge <NUM> extends between leading edge <NUM> and trailing edge <NUM>.

In <FIG>, window <NUM> is constructed so that its leading edge <NUM> and its trailing edge <NUM> are canted in opposite directions relative to the longitudinal axis of outer tube <NUM>, with first edge <NUM> and second edge <NUM> extending between leading edge <NUM> and trailing edge <NUM>.

<FIG> shows an alternative configuration for inner tube <NUM> and its opening <NUM>, wherein leading edge <NUM> extends perpendicular to the longitudinal axis of inner tube <NUM> and trailing edge <NUM> has a helical configuration.

The powered shaver of the present invention improves upon the deficiencies of the prior art.

Among other things, the new powered cutter provides enlarged window sizes, improved cutting action and superior suction.

Claim 1:
A cutting instrument comprising:
an outer tube (<NUM>) comprising a distal end (<NUM>) and a proximal end (<NUM>) and a longitudinal axis (<NUM>) extending therebetween;
an inner tube (<NUM>) rotatably disposed within said outer tube (<NUM>), said inner tube (<NUM>) comprising a distal end (<NUM>) and a proximal end (<NUM>) and a longitudinal axis (<NUM>) extending therebetween;
said inner tube (<NUM>) comprising an opening (<NUM>) having a leading edge (<NUM>) disposed proximal to said distal end (<NUM>) of said inner tube (<NUM>), and a trailing edge (<NUM>) disposed proximal to said leading edge (<NUM>); and
said outer tube (<NUM>) comprising a single window (<NUM>) formed therein, said window (<NUM>) of said outer tube (<NUM>) having a leading edge (<NUM>) disposed proximal to said distal end (<NUM>) of said outer tube (<NUM>), and a trailing edge (<NUM>) disposed proximal to said leading edge (<NUM>);
at least one of said leading edge (<NUM>) of said opening (<NUM>) and said trailing edge (<NUM>) of said opening (<NUM>) comprising a canted edge, said canted edge being canted relative to said longitudinal axis of said inner tube;
at least one of said leading edge (<NUM>) of said window (<NUM>) and said trailing edge (<NUM>) of said window (<NUM>) comprising a canted edge, said canted edge being canted relative to said longitudinal axis of said outer tube; and
said window (<NUM>) of said outer tube (<NUM>) being adapted to be completely blocked by said inner tube (<NUM>) during a phase of the rotation of said inner tube (<NUM>) within said outer tube (<NUM>),
characterised in that said leading edge (<NUM>) of said opening (<NUM>), said trailing edge (<NUM>) of said opening (<NUM>), said leading edge (<NUM>) of said window (<NUM>) and said trailing edge (<NUM>) of said window (<NUM>) all comprise a helix, wherein at least one of said leading edge (<NUM>) of said opening (<NUM>) and said trailing edge (<NUM>) of said opening (<NUM>) comprises a different pitch than at least one of said leading edge (<NUM>) of said window (<NUM>) and said trailing edge (<NUM>) of said window (<NUM>) .