Patent Publication Number: US-2023157718-A1

Title: Atherectomy catheter with serrated cutter

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/148,246, filed Oct. 1, 2018, titled “ATHERECTOMY CATHETER WITH SERRATED CUTTER,” now U.S. Patent Application Publication No. 2019/0029714 which is a continuation-in-part of PCT/US2017/025555, filed Mar. 31, 2017, titled “ATHERECTOMY CATHETER WITH SERRATED CUTTER,” now International Publication No. WO 2017/173370 which claims priority to U.S. Provisional Patent Application No. 62/317,214, filed Apr. 1, 2016, titled “ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES” and to U.S. Provisional Patent Application No. 62/317,231, filed Apr. 1, 2016, titled “SUPPORT ARM ASSEMBLY,” the entireties of which are incorporated by reference herein. 
     This application may be related to PCT Patent Application No. PCT/US 2015 / 014613 , filed Febr. 5, 2015, titled, “ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES”, Publication No. WO2015/120146A1, which is herein incorporated by reference in its entirety. 
    
    
     INCORPORATION BY REFERENCE 
     All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
     BACKGROUND 
     Peripheral artery disease (PAD) and coronary artery disease (CAD) affect millions of people in the United States alone. PAD and CAD are silent, dangerous diseases that can have catastrophic consequences when left untreated. CAD is the leading cause of death in the United States while PAD is the leading cause of amputation in patients over 50 and is responsible for approximately 160,000 amputations in the United States each year. 
     Coronary artery disease (CAD) and Peripheral artery disease (PAD) are both caused by the progressive narrowing of the blood vessels most often caused by atherosclerosis, the collection of plaque or a fatty substance along the inner lining of the artery wall. Over time, this substance hardens and thickens, which can cause an occlusion in the artery, completely or partially restricting flow through the artery. Blood circulation to the arms, legs, stomach and kidneys brain and heart may be reduced, increasing the risk for stroke and heart disease. 
     Interventional treatments for CAD and PAD may include endarterectomy and/or atherectomy. Endarterectomy is surgical removal of plaque from the blocked artery to restore or improve blood flow. Endovascular therapies such as atherectomy are typically minimally invasive techniques that open or widen arteries that have become narrowed or blocked. 
     In certain instances of CAD and PAD, extensive coronary calcification may occur. An increased risk of coronary heart disease is associated with extensive coronary calcification and is a sign of advanced atherosclerosis. Calcified plaque is more difficult to break apart than non-calcified plaque masses. As such, current atherectomy cutters used may not be as effective for breaking down calcified plaques. Thus, it would be advantageous to have a cutter that is better able to attack calcified plaque deposits during an atherectomy procedure. 
     Atherectomy catheter devices and the corresponding systems and methods that may address some of these concerns are described and illustrated below. 
     SUMMARY OF THE DISCLOSURE 
     Described herein are atherectomy catheters and methods of using them. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the drive shaft. The cutter includes a serrated annular cutting edge formed on a distal edge of the cutter and a recessed bowl extending radially inwards from the annular cutting edge to a center of the cutter. The recessed bowl has a first curvature. The cutter further includes a plurality of grinding segments extending inwardly from the distal edge within the bowl. Each of the plurality of segments has a second curvature that is different from the first curvature. 
     This and other embodiments can include one or more of the following features. Each of the plurality of grinding segments can be a flat facet configured to break calcified and hard fibrous disease in an artery. The second curvature can be larger than the first curvature, or smaller than the first curvature. The plurality of facets can be flat such that the second curvature is zero. The second curvature can be smaller than the first curvature. Each of the plurality of grinding segments can form a convex portion of the serrated annular cutting edge. Each of the plurality of grinding segments can form a concave portion of the serrated annular cutting edge. The serrated annular cutting edge can be angled radially inward relative an outer diameter of the elongate body. The serrated annular cutting edge can extend radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. The plurality of grinding segments can be disposed symmetrically around a circumference of the recessed bowl. The plurality of grinding segments can be disposed asymmetrically around a circumference of the bowl. The recessed bowl can further include a second recessed cavity off-center within the bowl. The bowl can further include a symmetric helical pattern of depressions that can extend from the serrated cutting edge inward towards the center of the cutter. The serrated annular cutting edge can include V-shaped cutouts extending along an outer wall of the cutter. The serrated annular cutting edge can include a plurality of shallow cutouts. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter includes a serrated annular cutting edge formed on a distal edge of the cutter, the serrated annular cutting edge angled radially inward relative an outer diameter of the elongate body, and a recessed bowl extending radially inwards from the annular cutting edge to a center of the cutter. 
     This and other embodiments can include one or more of the following features. The cutter can further include a plurality of grinding segments extending inwardly from the distal edge within the bowl. Each of the plurality of grinding segments can have a second curvature that can be different from the first curvature. The plurality of segments can be configured to break calcified and hard fibrous disease in an artery. Each of the plurality of grinding segments can be a flat facet. The second curvature can be smaller than the first curvature. Each of the plurality of grinding segments can form a convex portion of the serrated annular cutting edge. Each of the plurality of grinding segments can form a concave portion of the serrated annular cutting edge. The serrated annular cutting edge can be angled radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter includes a serrated annular cutting edge formed on a distal edge of the cutter. The serrated annular cutting edge includes a plurality of portions. Each of the plurality of portions have a convex shape and a recessed bowl extending radially inwards from the annular cutting edge to a center of the cutter. 
     This and other embodiments can include one or more of the following features. The cutter can further include a plurality of grinding segments extending inwardly from the distal edge within the bowl. Each of the plurality of grinding segments can have a second curvature that is different from the first curvature. The plurality of grinding segments can be configured to break calcified and hard fibrous disease in an artery. Each of the plurality of grinding segments can form a convex portion of the serrated annular cutting edge. Each of the plurality of grinding segments can be a flat facet. The second curvature can be smaller than the first curvature. The serrated annular cutting edge can be angled radially inward relative an outer diameter of the elongate body. The annular cutting edge can extend radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. The plurality of grinding segments can be disposed symmetrically around a circumference of the recessed bowl. The plurality of grinding segments can be disposed asymmetrically around a circumference of the recessed bowl. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a hollow distal tip extending from a distal end of the elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter has a serrated annular cutting edge formed on the distal end of the cutter and a recessed bowl extending radially inwards from the cutting edge to the center of the cutter. 
     This and other embodiments can include one or more of the following features. The bowl may be symmetric. The bowl may further include a second recessed cavity. The second recessed cavity may be positioned off center within the bowl. The second recessed cavity may cover about a third to about half of an area of the bowl. The secondary recessed cavity may include three regions. In this case, the seams delineating the three regions may be raised and form sharp edges. The recessed bowl may further include protruding features that are configured to contact with and grip onto calcified plaque. The serrated cutting edge may further include a series of half-circle scooped cutouts disposed around the perimeter of the serrated cutting edge. The recessed bowl may further include a plurality of off-axis scooped indentations that extend from the serrated cutting edge inward towards the center of the cutter. Intersections between the serrated cutting edge and the plurality of off-axis scooped indentations may form curved cutouts. The plurality of off-axis scooped indentations may further include seams that are raised relative to the rest of the off-axis scooped indentation surface and where the seams may have a sharp edge. The recessed bowl may further include a symmetric helical pattern of depressions that extends from the serrated cutting edge inward towards the center of the cutter, where seams that define the helical pattern can be raised relative to the rest of the symmetric helical pattern surface, and where the seams may have a sharp edge. The serrated annular cutting edge may include V-shaped cutouts that extend along an outer wall of the cutter. The serrated annular cutting edge can include asymmetric V-shaped cutouts that extend along an outer wall of the cutter. The serrated annular cutting edge may also include shallow cutouts disposed along its perimeter that extends along an outer wall of the cutter. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a hollow distal tip extending from a distal end of the elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter has a smooth annular cutting edge formed on the distal end of the cutter and a recessed bowl extending radially inwards from the cutting edge to a center of the cutter. The recessed bowl includes a series of pockets disposed along the recessed bowl&#39;s interior surface. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a hollow distal tip extending from a distal end of the elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter has a smooth annular cutting edge formed on the distal end of the cutter, a recessed bowl extending radially inwards from the cutting edge to a center of the cutter, and a cutter outer wall having a series of grooves that extend from just beneath the smooth annular cutting edge to the cutter out wall&#39;s bottom edge. 
     In general, in one embodiment, an atherectomy cutter includes a proximal end configured to couple with an atherectomy catheter, a distal end, a cutting edge disposed on the distal end, and a recessed bowl region disposed between the proximal end and the distal end. The cutting edge is disposed on an outer rim of the bowl region and includes a series of half circle cut outs distributed along a perimeter of the cutting edge. 
     In general, in one embodiment, an atherectomy cutter includes a proximal end configured to couple with an atherectomy catheter, a distal end, a cutting edge disposed on the distal end, and a bowl region disposed between the proximal end and the distal end. The cutting edge is disposed on an outer rim of the bowl region, and the bowl region includes an off-axis second cavity. 
     In general, in one embodiment, an atherectomy cutter includes a proximal end configured to couple with an atherectomy catheter, a distal end, a cutting edge disposed on the distal end, and a bowl region disposed between the proximal end and the distal end. The cutting edge is disposed on an outer rim of the bowl region, and the bowl region includes a series of off-axes scooped cuts that extend from the cutting edge towards the center of the bowl. An intersection between the cutting edge and each off-axes scooped cut forms an arced cut out. 
     In general, in one embodiment, an atherectomy cutter includes a proximal end configured to couple with an atherectomy catheter, a distal end, a cutting edge disposed on the distal end, and a bowl region disposed between the proximal end and the distal end. The cutting edge is disposed on an outer rim of the bowl region, and the bowl region includes a series of helically-patterned depressions that extend from an interior of the bowl region to the cutting edge. The cutting edge includes curved cut outs where the helically-patterned depressions intersect the cutting edge. 
     In general, in one embodiment, an atherectomy catheter includes an elongate body, a hollow distal tip extending from a distal end of the elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter has a recessed bowl extending radially inwards from the cutting edge to a center of the cutter, a cutter outer wall, and a serrated annular cutting edge formed on a distal end of the cutter. The serrated annular cutting edge includes a series of V-shaped grooves that extend from the serrated annular cutting edge and along the cutter outer wall to a proximal end of the cutter. 
     In general, in one embodiment, an atherectomy catheter includes an elongate body, a hollow distal tip extending from a distal end of the elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter has a recessed bowl extending radially inwards from the cutting edge to a center of the cutter, a cutter outer wall, and a serrated annular cutting edge formed on a distal end of the cutter. The serrated annular cutting edge includes a series of shallow cutouts that extend from the serrated annular cutting edge and along the cutter outer wall to a proximal end of the cutter. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a hollow distal tip extending from a distal end of the elongate body, a drive shaft extending proximally to distally within the elongate body, and a cutter attached to the driveshaft. The cutter has a recessed bowl extending radially inwards from the cutting edge to a center of the cutter, a cutter outer wall, and a serrated annular cutting edge formed on a distal end of the cutter. The serrated annular cutting edge includes a series of asymmetric V-shaped grooves that extend from the serrated annular cutting edge and along the cutter outer wall to a proximal end of the cutter. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a drive shaft, and a cutter. The drive shaft extends proximally to distally within the elongate body. The cutter is attached to the driveshaft and includes a serrated annular cutting edge and a recessed bowl. The serrated annular edge is formed on a distal edge of the cutter and includes a plurality of convex portions and each of the plurality of portions has a convex shape. The recessed bowl extends radially inwards from the annular cutting edge to a center of the cutter. This and other embodiments can include one or more of the following features. 
     The cutter further can include a plurality of grinding segments within the recessed bowl extending from the distal edge and each of the plurality of grinding segments can extend radially inwards relative to neighboring portions. The plurality of grinding segments can be configured to break calcified and hard fibrous disease tissue in an artery. 
     Each of the plurality of grinding segments can form a convex portion of the plurality of convex portions of the serrated annular cutting edge. Each of the plurality of grinding segments may be a flat facet. Each of the plurality of grinding segments may be a curved facet. Each of the plurality of grinding segments may be configured to extend at least 70% distally to proximally along the recessed bowl. Each of the plurality of grinding segments may be substantially square, rectangular, or trapezoidal in shape. Each of the plurality of grinding segments may form a convex portion of the serrated annular cutting edge. 
     The serrated annular cutting edge can be angled radially inward relative an outer diameter of the elongate body. The serrated annular cutting edge can extend radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. The serrated annular cutting edge can include a continuous wavy shape. 
     The plurality of grinding segments can be disposed symmetrically around a circumference of the recessed bowl. The plurality of grinding segments can be disposed asymmetrically around a circumference of the recessed bowl. 
     In general, in one embodiment, an atherectomy catheter device includes an elongate body, a drive shaft, and a cutter. The drive shaft extends proximally to distally within the elongate body. The cutter is attached to the driveshaft and includes a serrated annular cutting edge add a recessed bowl. The serrated annular cutting edge is formed on a distal edge of the cutter and is angled radially inward relative an outer diameter of the elongate body. The recessed bowl extends radially inwards from the annular cutting edge to a center of the cutter. This and other embodiments can include one or more of the following features. 
     The cutter further can include a plurality of grinding segments within the recessed bowl extending from the distal edge and each of the plurality of grinding segments can extend radially inwards relative to neighboring portions. The plurality of grinding segments can be configured to break calcified and hard fibrous disease tissue in an artery. 
     Each of the plurality of grinding segments can form a convex portion of the plurality of convex portions of the serrated annular cutting edge. Each of the plurality of grinding segments can be a flat facet. Each of the plurality of grinding segments can be a curved facet. Each of the plurality of grinding segments can extend at least 70% distally to proximally along the recessed bowl. Each of the plurality of grinding segments can be substantially square, rectangular, or trapezoidal in shape. Each of the plurality of grinding segments can form a convex portion of the serrated annular cutting edge. Each of the neighboring portions can form a concave portion of the serrated annular cutting edge. 
     The serrated annular cutting edge can be angled radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. The serrated annular cutting edge can include a continuous wavy shape. 
     The plurality of grinding segments can be disposed symmetrically around a circumference of the recessed bowl. The plurality of grinding segments can be disposed asymmetrically around a circumference of the recessed bowl. 
     Also described herein are support systems for maintaining medical components, such as controller components of an atherectomy catheter, at a convenient location with easy maneuverability relative to the treatment site. 
     In general, in one embodiment, a catheter controller support apparatus includes a rail clamp configured to releaseably attach to a rail, a support arm having at least two segments joined by a swivel joint that is configured to couple with the rail clamp through a coupling post, and a catheter controller mount coupled to the support arm and configured to securely maintain a catheter controller. 
     This and other embodiments may include one or more of the following features. The rail clamp may include a top surface, a support arm coupler disposed on the top surface, a support arm coupling aperture disposed on the support arm coupler, a top jaw, a bottom jaw hinged with the top jaw, a lever for actuating the up and down movement of the top and the bottom jaw, and a support arm securing aperture for locking the support arm in position. The rail clamp may further include a course adjustment knob for increasing and decreasing the distance between the top jaw and the bottom jaw. The rail clamp may further include at least one sleeve bearing contained within the arm coupling aperture. The support arm may further include a first friction knob configured to maintain the swivel joint in a fixed position once the desired position is obtained. The support arm may further include a second swivel joint and a corresponding second friction knob adjacent to the coupling post configured to provide articulated/segmental adjustment of the support arm. The support arm may further include a catheter mount coupler adapted to couple to the catheter controller mount, wherein the catheter mount coupler may further include a mount positioning lever that configured to adjust the angle at which the catheter controller mount is positioned. The support arm may further include at least one cable retainer. The catheter controller mount may further include a catheter controller coupler, wherein the catheter controller coupler may be a post or other protrusion extending from the base of the catheter controller mount that inserts into a corresponding aperture of the catheter controller. The catheter controller mount may further include a controller mount support latch. The catheter controller mount may include a clip having a jaw wide enough to accommodate the catheter controller. The catheter controller mount may include a mount support base, a mount support coupler configured to couple to a catheter controller unit, and a mount support latch for stabilizing the coupled catheter controller unit. 
     In general, in one embodiment, a catheter controller support apparatus includes a rail clamp configured to releaseably attach to a rail, a support arm coupler disposed on the top surface, a support arm coupling aperture disposed on the support arm coupler, a top jaw, a bottom jaw hinged with the top jaw, a lever for actuating the up and down movement of the top and the bottom jaw, and a support arm securing aperture for locking the support arm in position. The rail clamp includes a top surface. The support arm has at least two segments joined by a swivel joint that is configured to couple with the rail clamp through a coupling post. The at least two segments are coupled by a swivel joint and at least one friction knob maintains the swivel joint in a fixed position once the desired position is obtained. The catheter controller support apparatus further includes a catheter controller mount coupled to the support arm and configured to securely maintain a catheter controller. The catheter controller mount further includes a catheter controller coupler. The catheter controller coupler includes a post or other protrusion extending from the base of the catheter controller mount that inserts into a corresponding aperture of the catheter controller, a mount support base, a mount support coupler able to couple to a catheter controller unit, and a mount support latch configured to stabilize the coupled catheter controller unit. 
     This and other embodiments may include one or more of the following features. The rail clamp may further include at least one sleeve bearing contained within the arm coupling aperture. The support arm may further include a catheter mount coupler configured to couple to the catheter controller mount, wherein the catheter mount coupler may further include a mount positioning lever that is configured to adjust the angle at which the catheter controller mount is positioned. The support arm may further include at least one cable retainer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A- 1 C  illustrate a side perspective view of the end of an exemplary atherectomy device having an offset hinged region, a bushing, and an imaging/cutting assembly with a neck region that engages the bushing.  FIG.  1 B  shows the catheter with the housing for the hollow distal tip removed.  FIG.  1 C  shows the catheter of  FIG.  1 B  with the proximal connector to the outer sleeve of the elongate body removed, showing the bushing and rotatable drive shaft. 
         FIG.  2 A  shows a sectional view though an atherectomy catheter such as the one shown in  FIGS.  1 A- 1 C , with the distal tip in-line with the elongate (proximal) body region. 
         FIG.  2 B  shows the catheter of  FIG.  2 A  as the tip is beginning to be displaced downward. 
         FIG.  2 C  shows the catheter of  FIG.  2 A  with the tip fully displaced downward, exposing the cutting edge of the cutting/imaging assembly. 
         FIG.  3    shows a catheter with the cutting/imaging assembly extended distally into the distal tip region. 
         FIGS.  4 A- 4 D  illustrate another variation of an atherectomy catheter.  FIGS.  4 B,  4 C and  4 D  each show the catheter of  FIG.  4 A  with various components removed to allow description of internal parts. 
         FIG.  5    illustrates a handle for an atherectomy catheter. 
         FIG.  6    shows one variation of a distal end of an atherectomy having a plurality of balloons that are arranged and may be used to provide a mechanical advantage in driving the cutting edge against the vessel wall. 
         FIGS.  7 A- 7 D  show perspective, side, top and front views, respectively of a bushing for an atherectomy device. 
         FIG.  8 A  shows a panoramic OCT image of a blood vessel through the nosecone of an atherectomy catheter, as identified by the arrow in  FIG.  8 B . 
         FIG.  9 A  shows a panoramic OCT image of a blood vessel taken with an atherectomy catheter through the cutting window(s) when the nosecone is closed and the cutter is in a passive position, as identified by the arrow in  FIG.  9 B . 
         FIG.  10 A  shows a panoramic OCT image of a blood vessel taken with an atherectomy catheter through cutting window(s) when the nosecone is open, as identified by the arrow in  FIG.  10 B . 
         FIGS.  11 A- 11 B  show another embodiment of an atherectomy catheter having a cutter engaging distal surface that is normal to the longitudinal axis of the catheter.  FIG.  11 A  shows a cross-section of the catheter while  FIG.  11 B  shows a side view of the bushing. 
         FIGS.  12 A- 12 B  show another embodiment of an atherectomy catheter having a cutter engaging distal surface that is at an angle relative to the longitudinal axis so as to provide only a point of contact with the distal surface of the cutter.  FIG.  12 A  shows a cross-section of the catheter.  FIG.  12 B  shows a side view of the bushing. 
         FIG.  13 A  shows the removal of a single, long strip of material cut from the tissue by an atherectomy catheter as described herein.  FIGS.  13 B and  13 C  show the length of tissue removed. 
         FIGS.  14 A and  14 B  show a bushing having jet channels therethrough to assist in packing of tissue into the nosecone of an atherectomy catheter. 
         FIG.  15    shows a cross-section of an atherectomy catheter with a crescent-shaped balloon. 
         FIGS.  16 A- 16 C  show an atherectomy catheter with a crescent-shaped balloon. 
         FIG.  17 A  shows an atherectomy catheter having a serrated cutting edge. 
         FIG.  17 B  shows a close-up of the serrated cutter portion of the atherectomy catheter of  FIG.  17 A . 
         FIGS.  18 A- 18 E  show an atherectomy catheter cutter having a serrated cutting edge and an asymmetric pocket within the cutter body.  FIGS.  18 A and  18 B  are isometric views of the cutter.  FIG.  18 C  is a side view of the cutter.  FIG.  18 D  is a front view of the cutter.  FIG.  18 E  is a cross-sectional side view of the cutter. 
         FIGS.  19 A- 19 E  show an atherectomy catheter cutter having a serrated cutting edge and a symmetric pocket within the cutter body.  FIGS.  19 A and  19 B  show isometric views of the cutter.  FIG.  19 C  is a side view of the cutter.  FIG.  19 D  is a front view of the cutter.  FIG.  19 E  is a cross-sectional side view of the cutter. 
         FIGS.  20 A- 20 E  show an atherectomy catheter cutter having rotationally asymmetric depressions therein.  FIGS.  20 A and  20 B  show isometric views of the cutter.  FIG.  20 C  is a side view of the off-axis cutter.  FIG.  20 D  is a front view of the cutter.  FIG.  20 E  is a cross-sectional side view of the cutter. 
         FIGS.  21 A- 21 E  show an atherectomy catheter cutter having a helical depressions therein.  FIGS.  21 A and  21 B  show isometric views of the cutter.  FIG.  21 C  is a side view of the cutter.  FIG.  21 D  is a front view of the cutter.  FIG.  21 E  is a cross-sectional side view of the cutter. 
         FIGS.  22 A- 22 B  show an atherectomy catheter cutter having a smooth cutting edge having a series of pockets disposed within a bowl region.  FIG.  22 A  is a perspective view of the cutter and  FIG.  22 B  is a front view of the bowl region. 
         FIGS.  23 A- 23 B  show an atherectomy catheter cutter having grooved cutting edges disposed on the outer rim of a bowl region, where the grooves also extend along the outer wall of the cutter.  FIG.  23 A  is a perspective view of the cutter and  FIG.  22 B  is a front view of the bowl region. 
         FIGS.  24 A- 24 B  show an atherectomy catheter cutter having shallow cutouts in the cutting edge disposed on the outer rim of a bowl region. The shallow cutouts also extend along the outer wall of the cutter.  FIG.  24 A  shows a perspective view of the cutter, while  FIG.  24 B  is a front view of the bowl region. 
         FIGS.  25 A- 25 B  show an atherectomy catheter cutter having asymmetric grooves in the cutting edge disposed on the outer rim of a bowl region. The asymmetric groove also extends along the outer wall of the cutter.  FIG.  25 A  shows a perspective view of the cutter, while  FIG.  25 B  is a front view of the bowl region. 
         FIGS.  26 A- 26 B  show an atherectomy catheter cutter having a smooth cutting edge disposed around a bowl region of the cutter, where the outer wall of the cutter includes a series of grooves.  FIG.  26 A  shows a perspective view of the cutter, while  FIG.  26 B  shows a front view of the bowl region. 
         FIGS.  27 A- 27 E  illustrate an atherectomy catheter device including a cutter having a serrated annular cutting edge, a recessed bowl, and a plurality of segments according to one embodiment. Each of the segments is a flat facet having a concave portion on the cutting edge.  FIG.  27 A  is a shaded perspective view of the cutter,  FIG.  27 B  is a line perspective view of the cutter,  FIG.  27 C  is a side view of the cutter,  FIG.  27 D  is a front view of the cutter and  FIG.  27 E  is a cross-sectional side view of the cutter. 
         FIGS.  28 A- 28 E  illustrate an atherectomy catheter device including a cutter having a serrated annular cutting edge, a recessed bowl, and a plurality of segments according to another embodiment.  FIG.  28 A  is a shaded perspective view of the cutter,  FIG.  28 B  is a line perspective view of the cutter,  FIG.  28 C  is a side view of the cutter,  FIG.  28 D  is a front view of the cutter and  FIG.  28 E  is a cross-sectional side view of the cutter. 
         FIGS.  29 A- 29 E  illustrate an atherectomy catheter device including a cutter having a serrated annular cutting edge, a recessed bowl, and a plurality of segments according to one embodiment.  FIG.  29 A  is a shaded perspective view of the cutter,  FIG.  29 B  is a line perspective view of the cutter,  FIG.  29 C  is a side view of the cutter,  FIG.  29 D  is a front view of the cutter and  FIG.  29 E  is a cross-sectional side view of the cutter. 
         FIGS.  30 A- 30 E  illustrate an atherectomy catheter device including a cutter having a serrated annular cutting edge, a recessed bowl, and a plurality of segments according to one embodiment.  FIG.  30 A  is a shaded perspective view of the cutter,  FIG.  30 B  is a line perspective view of the cutter,  FIG.  30 C  is a side view of the cutter,  FIG.  30 D  is a front view of the cutter and  FIG.  30 E  is a cross-sectional side view of the cutter. 
         FIGS.  31 A-  31 E  illustrate an atherectomy catheter device including a cutter having a serrated annular cutting edge, a recessed bowl, and a plurality of segments according to one embodiment.  FIG.  31 A  is a shaded perspective view of the cutter,  FIG.  31 B  is a line perspective view of the cutter,  FIG.  31 C  is a side view of the cutter,  FIG.  31 D  is a front view of the cutter and  FIG.  31 E  is a cross-sectional side view of the cutter. 
         FIG.  32 A  is a perspective view of a support arm assembly. 
         FIG.  32 B  is an exploded view of the support arm assembly of  FIG.  32 A . 
         FIG.  32 C  is a top view of the support arm portion of the support arm assembly of  FIG.  32 A . 
         FIG.  33 A  is a perspective of an adjustment knob screw. 
         FIG.  33 B  is an exploded view of the adjustment knob screw of  FIG.  33 A . 
         FIG.  34 A  is a perspective view of a side rail clamp. 
         FIG.  34 B  is an exploded view of the side rail clamp of  FIG.  34 A . 
         FIG.  34 C  is a perspective view of the bottom jaw of the side rail clamp of  FIG.  34 A . 
         FIG.  34 D  is a perspective view of a side cam level adjustor of the side rail clamp of  FIG.  34 A . 
         FIG.  34 E  is a perspective view of the side cam lever of the side rail clamp of  FIG.  34 A . 
         FIG.  35 A  is a perspective of a cable retainer. 
         FIG.  35 B  is an exploded view of the cable retainer of  FIG.  35 A . 
         FIG.  35 C  is a perspective view of a top jaw of the cable retainer of  FIG.  35 A . 
         FIG.  36 A  is a perspective view of a catheter controller mount. 
         FIG.  36 B  is an exploded view of the catheter controller mount of  FIG.  36 A . 
         FIG.  36 C  shows the catheter controller mount of  FIG.  36 A  coupled to a catheter controller. 
         FIGS.  37 A- 37 B  shows another embodiment of a rail clamp. 
         FIG.  38    shows another embodiment of a catheter controller mount. 
         FIGS.  39 A- 39 B  show another embodiment of a catheter controller mount coupled to a catheter controller. 
         FIGS.  40 A- 40 B  show another embodiment of a catheter controller mount. 
         FIG.  40 C  shows the catheter controller mount of  FIG.  40 A  coupled to a catheter controller. 
         FIG.  41 A  shows another embodiment of a catheter controller mount. 
         FIG.  41 B  shows the catheter controller mount of  FIG.  41 A  coupled to a catheter controller. 
         FIGS.  42 A- 42 F  show an atherectomy catheter cutter having a serrated cutting edge.  FIGS.  42 A and  42 B  are isometric views of the cutter.  FIG.  42 C  is a side view of the cutter.  FIG.  42 D  is a front view of the cutter.  FIGS.  42 E- 42 F  are cross-sectional side views of the cutter. 
     
    
    
     DETAILED DESCRIPTION 
     The atherectomy catheters described herein can include a cutter. The cutter, for example, can have a serrated annular cutting edge formed on a distal edge of the cutter and a recessed bowl extending radially inwards from the annular cutting edge to a center of the cutter. The recessed bowl can include a plurality of segments therein configured to help break up hard plaque or diseased tissue that enters the recessed bowl during use. 
     The atherectomy catheters described herein can further include a catheter shaft with a drive chassis on the end. The drive chassis includes a stout torque coil (“imaging torqueing coil”/drive shaft) for rotating an imaging element, a cutter, and an imaging optical fiber in the center of the torque coil. Both the imaging elements and the cutter can be part of a head that rotates with the driveshaft. The head can rotate in a single direction (e.g., clockwise). The head can further slide distally/proximally by pushing or pulling the torque coil/drive shaft. As a result of the movement of the driveshaft, a nosecone configured to hold tissue can be displaced. In some embodiments, the nosecone can open and close using an off-axis hinge. In other embodiments, a cam member and cam slot can be used to open and close the nosecone. 
       FIGS.  1 A- 3    show an example of an atherectomy catheter  100  including a nosecone that deflects to expose a cutter. The atherectomy catheter  100  can include a catheter body  101  having an outer shaft  111 , a cutter  103  at a distal end of the catheter body  101 , and a nosecone  105  at a distal end of the catheter body  101 . The nosecone  105  can further include a cutting window  107  through which the cutting edge  112  of the cutter  103  can be exposed. The nosecone  105  can be configured to deflect away from the longitudinal axis of the catheter body  101  about a hinge point  1109 , as described further below. This deflection can expose the cutter  103  through the cutting window  107  and/or radially push the cutter  103  into a wall of the vessel in which the atherectomy catheter is inserted. 
     Referring to  FIGS.  1 A- 2 C , the cutter  103  can be positioned between the catheter body  101  and the nosecone  105  via a bushing  155 . In some embodiments, the cutter  103  can be an annular cutter with a sharp distal edge  112 . The cutter  103  can be attached to a drive shaft  113  configured to rotate the cutter  103 . 
     Further, referring still to  FIGS.  2 A- 2 B , the atherectomy catheter  100  can include an imaging element  192 , such as an OCT imaging element, within the cutter  103  and proximal to the cutting edge  112  of the cutter  103 . The imaging element  192  can include an optical fiber  197  that runs substantially on-axis through the center of the elongate body, such as through the driveshaft  113 , to transmit the OCT signal. Further, the optical fiber  197  can run straight throughout the catheter body  101  without bending. The optical fiber  197  can be attached at the distal end to the cutter  103 , such as in a slot  177  in the cutter  103 . The slot can have a length that extends at least to the center of the cutter  103  so as to allow the optical fiber  197  to remain on-axis without a bend through the length of the catheter body  101  and the cutter  103 . Aside from the attachment to the cutter  103 , the optical fiber  197  can be otherwise be free to float within the catheter body or drive shaft  113 . In other embodiments, the optical fiber  197  can be attached to the drive shaft  113  along the length thereof. 
     As shown in  FIGS.  2 A- 2 C , the imaging element  192  can include a reflective element  199 , such as a mirror. The reflective element  199  can be located within the slot  177  in the cutter  103  to radially direct light from the optical fiber  197  into the adjacent tissue (through the cutter window  107 ). The reflective element  199  can be oriented at an angle relative to the axis of the optical fiber  197 , such as at a 35-55 degree angle, e.g. 45 degree angle, to reflect light into the tissue. The distal end of the optical fiber  197  can be located less than 3 mm from the cutting edge, such as less than 1 mm from the cutting edge, such as less than 0.5 mm. By having the imaging element  192  close to the cutting edge, the resulting image can advantageously align with the portions of the vessel being cut. 
     In use, the outer shaft  111  can be configured to be turned, such as turned manually, to position the cutter window  107 , cutter  103 , and/or the imaging element  192  toward the desired location. The driveshaft  113  can then be rotated to rotate the cutter  103  and the imaging elements  197 . Rotation of the cutter can provide cutting due to the rotational motion of the cutting edge and provide the rotation necessary to image the vessel wall via the imaging element. The drive shaft can be rotated at up to 2,000 rpm, such as approximately 1,000 rpm in a single direction, though rotation in both directions or at higher or lower speeds is possible. 
     Referring to  FIGS.  2 A- 2 C , the drive shaft  113  can further be configured to translate axially in the proximal and/or distal directions. Such axial movement of the drive shaft  113  can open and/or close the nosecone  105  about the hinge point  1109  (e.g., a pin in the bushing  155 ) to expose or conceal and protect the cutting edge  112  of the cutter  103 . For example, the bushing  155  can include an inner flange  170  that extends radially inwards. The inner flange  170  can be positioned distal to the hinge point  1109 . The bushing  155  can further include sloped outer distal surface  143  that angles radially inward from the distal end to the proximal end. Finally, the cutter  103  can include a proximal edge  166  and a tapered neck  168  that gets narrower from the driveshaft  113  to the head of the cutter  103 . The interaction of these various elements can open and close the nosecone  105 . 
     In one embodiment, proximal retraction of the drive shaft  113  opens the nosecone  105  to expose the cutter. For example, as the driveshaft  113  is pulled proximally, the proximal edge  166  of the cutter  103  is forced against the sloped distal surface  143  of the bushing  155 . Because the sloped distal surface  143  angles radially inward from the distal end to the proximal end, the cutter  103  forces the bushing  155 , and thus the nosecone  105 , to deflect away from the longitudinal axis of the catheter body  101 , thereby opening the nosecone  105  (see the transition from  FIGS.  2 A to  2 B and  2 B to  2 C ). The cutting window  107  can have an opening that is larger than the diameter of the cutter  103  and cutting edge  112  to allow the cutter  103  to protrude out of the nosecone  105  when the nosecone  105  is deflected. 
     In one embodiment, distal movement of the drive shaft  113  closes the nosecone  105 . For example, as shown in  FIGS.  2 A- 2 C , when the drive shaft  113  is pushed distally, the tapered neck  168  of the cutter  103  will correspondingly move distally. The distal movement of the tapered neck  168  causes the inner flange  170  of the bushing  155  to drag along the widening edges of the tapered neck  168 , thereby lifting the bushing  155 , and correspondingly, closing the nosecone  105  (see the transition from  FIGS.  2 C to  2 B and  2 B to  2 A ). Because the hinge point is proximal to the inner flange  170 , a mechanical advantage is achieved that allows for complete closing of the nosecone. 
       FIGS.  7 A- 7 D  show close-ups of the bushing  155 . As shown, the bushing  155  can include two intersecting channels  721 ,  723  configured to hold the necked portion  168  of the imaging subassembly therein when the nosecone is in the open configuration (channel  723 ) and the closed configuration (channel  721 ). Channel  721  extends through a long distal to proximal axis of the bushing  155  while channel  723  extends at an angle relative to channel  721  and overlaps therewith. The bushing  155  can further include a hinge channel  745  formed through a top peripheral region of the bushing  155  so as to provide the pivot point  1109 . The hinge channel  745  can be transverse to the channel  721 . 
     Other mechanisms of opening and closing the nosecone are possible. For example, as shown in  FIGS.  4 A- 4 D , in one embodiment, a catheter  200  (having similar features to catheter  100  except the opening and closing mechanisms) can include a cam slot  228  in the bushing  155  that angles toward the cutting window  107  from the proximal end to the distal end. Further, a cam member  290  can be attached to the cutter  103  and configured to extend through the cam slot  228 . Thus, as the driveshaft  113 , and thus cam member  290 , are pushed distally, the cam member  290  will move within the angled cam slot  180 . The movement of the cam member  290  within the angled cam slot  180  causes the bushing  155 , and thus the nosecone  150 , to drop down. Conversely, to close the nosecone, the driveshaft  113  can be pulled proximally, thereby causing the cam member  290  to ride within the cam slot  228  and pull the bushing  155  back into line with the elongate body  101 . 
     Another mechanism of opening and closing a nosecone of an atherectomy catheter  400   a, b  is shown in  FIGS.  11 A- 11 B and  12 A- 12 B . The catheter  400   a, b  can have the same features as catheter  100  except that the outer distal surface  443   a,b  of the bushing  455   a,b  can be either normal to the longitudinal axis of the device (such that the angle a is 90 degrees), as shown in  FIG.  11 B  or slanted radially outward from the distal end to the proximal end (such that the angle a is greater than 90 degrees and the angle with the longitudinal axis is less than 90 degrees), as shown in  FIG.  12 B . In the embodiment of  FIGS.  12 A- 12 B , an angled space is provided between the proximal edge  166  of the cutter and the distal surface  443   b  such that the only point of contact is an inner radial edge  444  of the bushing  455   b . The catheter  400   a  will open and close similarly to as described with respect to catheter  100 . However, the catheter  500   b  will open slightly differently in that only the inner-most radial edge  444  will interact with the proximal edge  166  of the cutter  103 , as opposed to the entire surface  443 , when the driveshaft  113  is pulled proximally. Such a configuration can advantageously reduce friction while opening the nosecone  105 . In some embodiments, the proximal edge  166  can be angled with respect to a longitudinal axis of the catheter; in such cases, the opposing surface  443  of the bushing  455  can be either parallel to or angled (acute or obtuse) with respect to the proximal edge  166 . 
     As shown in  FIG.  3   , the atherectomy catheter  100  (or  200  or  400 ) can further include a mechanism for packing tissue into the nosecone, such as by moving the drive shaft axially. In one embodiment, movement of the drive shaft  113  distally closes the nosecone  105 . Moving the drive shaft  113  further distally will move the cutter  103  into a passive position (i.e., against a distal edge of the window  107 ) where the cutter  103  can be protected by the edge of the window  107  to avoid undesired cutting of the vessel during use. Moving the drive shaft  113  further distally will move the cutter  103  into the nosecone  105 , thus packing tissue with a distal face of the cutter  103 , as shown in  FIG.  3   . The cutter  103  can move more than 0.5 inches, such as more than 1 inch or more than 2 inches into the nosecone  105  to pack the tissue. In some embodiments, the nosecone  105  is formed of a material that is OCT translucent (e.g., non-metallic) so that panoramic OCT images can be taken therethrough. 
     Referring to  FIGS.  14 A- 14 B , in some embodiment a bushing  1655  can include all of the features of the bushings described above, but can additionally include jet channels  1785   a,b  cut into the inner circumference thereof and extending from the proximal end to the distal end. The jet channels  1785   a,b  can connect a fluid line within the elongate body  101  to the nosecone  105 . Fluid flowing through the jet channels  1785   a, b  can increase speed and thus provide enough force to pack cut material into the nosecone and clear the imaging region within the nosecone. Further, the jet channels can create a venturi effect at the distal end of the bushing  1655 , which can suck material into the nosecone and/or away from the imaging/cutting head and/or the distal end region of the elongate body. 
     In one embodiment, the atherectomy catheter  100  (or  200  or  400 ) includes a guidewire lumen in the nosecone  105 , such as a monorail, for use in guiding the catheter. Advantageously, the guidewire lumen can be used as a marker during imaging. 
     In some embodiments of atherectomy catheters  100 ,  200 , or  400 , there can be one or more small imaging windows  207 ,  307  in the nosecone  105  opposite to the cutting window  107 , as shown in  FIGS.  1 A and  2 A- 2 C . These additional imaging windows  207  can provide more of a  180  degree view during imaging. Further, one set of windows  207  can be more proximal and configured to be axially aligned with the cutter  103  and the imaging element  192  when the nosecone is opened while the other set of windows  307  can be more distal and configured to be axially aligned with the cutter  103  and the imaging element  192  when the nosecone is closed and the cutter  103  is in the passive position. In some embodiments, the imaging windows  307 ,  207  have different shapes from one another to further help identify cutter position in the resulting OCT images. 
     Referring to  FIGS.  8 A- 11 B , the OCT image catheter with the device will vary depending upon the placement of the imaging device in the three different configurations (nosecone open, nosecone closed with cutter in cutting position, nosecone closed with cutter in packing position). Accordingly, a user can identify, simply by looking at the imaging display, whether the nosecone  105  is displaced and whether the cutter  103  is in the cutting or packing position. 
     For example,  FIG.  8 A  shows a panoramic image  800  of a surrounding vessel when the cutter  103  (and, correspondingly, the imaging sensor) is in the cutting position, as shown in  FIG.  8 B . The wall of the nosecone  105  is displayed as the circular feature  808  in the image  800 . Further, because the nosecone  105  is made of a clear material, the vessel tissue  806  can be imaged even through the nosecone  105 . As can be seen in image  800 , a 180 degree view of the tissue  806  can thus be obtained. The circular artifact  803  in the image (and here, the radial line  801 ) correspond to a guidewire and/or guidewire channel running alongside the nosecone  105 . 
     In contrast to image  800 ,  FIG.  9 A  shows a panoramic image  900  of a surrounding vessel when the cutter  103  is in the passive position and the nosecone  105  is closed, as shown in  FIG.  9 B . A  180  degree view of the vessel tissue  906  is shown on the right side of the image (taken through window  107 ) while the closed nosecone  909  is shown on the left side of the image (the lines  909   a,b  correspond to the bushing wall). The space  913  between the lines  909   a,b  through which tissue  906  can be seen on the left side of the image is taken through the additional window  307  in the bushing. Further, the distance between the arrows in image  900  indicates that the distal tip is “closed” (and close therefore close to the midline of the catheter). 
     Finally, in contrast to image  900 ,  FIG.  10 A  shows a panoramic image  1000  of a surrounding vessel when the cutter  103  is in the cutting position and the nosecone  105  is open, as shown in  FIG.  10 B . The vessel tissue  1006  (taken through window  107 ) is shown on the right side of the image while the closed nosecone  1009  is shown on the left side of the image (the lines  1009   a,b  correspond to the bushing wall). The space  1013  between the lines  1009   a,b  through which tissue  1006  can be seen is taken through the window  207 . A comparison of the relative distance between the arrows in  FIGS.  9 A and  10 A  shows an increased distance between the catheter body and the nosecone, thereby suggesting to the operator that the nosecone  105  is in an open position. Further, in some embodiments, when the nosecone is open or closed, the image resulting from the window  207 / 307  will look different due to the angle change between the windows  207 / 307  and the imaging element  297  and/or the different shape of the windows  207 / 307 . 
     In one embodiment, the atherectomy catheter  100  (or  200  or  400 ) includes a flush port close to the cutter  103 . The flush port can be used to deliver flushing fluid to the region of imaging, thereby improving image quality. In some embodiments, the flushing can be activated through a mechanism on the handle of the device. The fluid can, for example, be flushed in the annular space between the catheter body  101  and the driveshaft  113 . Further, in embodiments with jet channels in the bushing, the annular space can connect to the jet channels to provide fluid thereto. 
     Referring to  FIG.  6   , in some embodiments, the atherectomy catheters  100 ,  200 ,  400  can further include two or more balloons configured to help urge the cutter  103  into the tissue. The first balloon  333  can be the distal-most balloon. The first balloon  333  can be positioned proximate to the hinge point  1109  and opposite to the cutting window  1107 . The balloon  333  can urge the cutter  103  against the tissue by deflecting the cutter  103  up and into the tissue. A second balloon  335 , proximal to the distal balloon  333 , can be on the same side of the catheter  100  as the cutting window  107  and can further help drive the cutter  103  into the tissue by. In some embodiments, the second balloon  335  can be annular. In some embodiments, the second balloon  335  can help occlude the vessel. Further, in some embodiments (and as shown in  FIG.  6   ), a third balloon  337  can be used for occlusion. One or more of the balloons  333 ,  335 ,  337  can be configured to as to expand with little pressure, such as less than 2 psi. This low pressure advantageously prevents the balloons  333 ,  335 ,  337  from pushing hard against the vessel wall, but still provides enough pressure to urge the cutter  103  into the tissue. The balloons  333 ,  335 ,  337  can further include tapered edges on the proximal and distal edges that allow the balloon to slide along the vessel and/or fit through tortuous regions. 
     Referring to  FIGS.  15  and  16 A- 16 C , in another embodiment, the atherectomy catheters  100 ,  200 ,  400  can include a single balloon configured to both urge the cutter  103  into the tissue and occlude blood flow to improve imaging. Referring to  FIG.  15   , the balloon  1733  can have a crescent shape, i.e., can be wrapped around the catheter  100  so as to cover the entire circumference of the catheter  100  except where the cutter  103  is exposed. By using a balloon  1733  with such a shape, the gaps between the catheter  100  and the vessel  1723  are substantially reduced, advantageously negating or reducing the localized flushing required to displace blood from the visual field. In one embodiment, to create the crescent shape, the balloon includes wide necks at both ends that are then wrapped around the nosecone  105  and elongate body  101  such that they cover at least half of the circumferential surface.  FIG.  16 A  shows the wrapped balloon edges  1735  while  FIG.  16 B  shows the wide necks  1737  fused at both ends.  FIG.  16 C  shows an inflation port  1739  contained inside the balloon  1733  as well as a guidewire lumen  1741  that spans the length of the balloon  1733 . In some embodiments, the balloon  1733  can be used to open or close the nosecone without requiring proximal or distal movement of the driveshaft. 
     Referring to  FIG.  5   , a handle  300  can be used to control the rotation or translation of the driveshaft for the catheter  100 ,  200 , or  400 . The handle  300  can advantageously allow the optical fiber to move distally and proximally with the cutter as it is driven without requiring the fiber to move at a proximal location, e.g., without requiring movement of the optical fiber assembly within the drive assembly. Thus, the handle  300  can be design to completely account for movement of the drive shaft. An exemplary driveshaft management system  555  is shown in  FIG.  5   . The driveshaft management system  555  allows the user to position the driveshaft distally or proximally as the driveshaft is simultaneously spinning at a high speed. In some embodiments, the driveshaft can be configured such that it is fully tensioned before the driveshaft management system  555  is positioned at its most proximal position. That is, the driveshaft management system  555  can include a driveshaft tensioning spring  556 . The spring  556  can be configured such that, as the user positions the slideable user ring  557  (or button) proximally, the driveshaft is fully tensioned and the driveshaft management system  555  is moved proximally, causing the spring  556  to compress and apply a controlled tensile load on the driveshaft. This fiber management system  555  advantageously enhances performance of the catheter by tensioning the driveshaft with a pre-determined load to properly position the cutting and imaging component against the bushing at the distal end of the catheter, improving cutting and imaging of the catheter. 
     The driveshaft management system  555  can transmit torque originating from a drive assembly, as described further below. Connection to the drive assembly can be made at the optical connector  559 . Torque can thus be transmitted from the optical connector  559 , through the fiber cradle  551 , to the drive key  560 , through the driveshaft management system  555 , and then directly to the catheter driveshaft, all of which can rotate in conjunction. The fiber cradle  551  can include a set of components (i.e., a pair of pieces to make the whole fiber cradle) that houses the proximal end of the optical fiber and transmits torque within the driveshaft system. The fiber cradle components can be thin-walled by design, thereby creating a hollow space inside. Within this hollow space of the fiber cradle  551 , the optical fiber can be inserted or withdrawn as the device driveshaft is positioned proximally or distally. As the fiber is inserted into the fiber cradle  551  when the user ring  557  is positioned proximally, the fiber is able to coil within the internal space of the fiber cradle  551  while maintaining imaging throughout its length to the distal tip. Conversely, as the fiber is withdrawn from the fiber cradle  551  when the user ring  557  is positioned distally, the coiled section of fiber is able to straighten while maintaining imaging throughout its length to the distal tip. This design feature advantageously provides more fiber capacity or “slack” to the overall driveshaft system to increase the range in which the driveshaft system can be translated. 
     The handle  300  can further include a balloon inflation chamber  552  configured to connect to a balloon inflation lumen (e.g., for use with a balloon on the catheter as described above) on one side and to balloon inflation tubing  553  and/or a port  554  on the other side. Because the inflation fluid transfers to the balloon through the balloon inflation chamber  552 , the outer shaft  111  can advantageously rotate (e.g., by rotating the knob  558 ) independently of the balloon inflation chamber  552 , allowing the tubing  553  and/or port  554  to remain stationary during rotation of the outer shaft  111 . 
     Moreover, as shown in  FIG.  5   , the handle  300  can further include a catheter flush chamber  663  and catheter flush tubing  664  and/or flush port  665  to provide flushing through the catheter, as described above. 
     Any of the atherectomy catheters described above can be used with a cutter having a serrated distal edge designed to remove calcified and hard fibrous disease in an artery. The calcified and hard fibrous disease can be difficult to remove due to its increased hardness compared to plaque. While a standard cutter may have no problem debulking the majority of arterial plaque, in certain instances, the plaque encountered by an atherectomy catheter may be harder and/or of a greater volume than what is typically encountered. This may be due to plaque having a larger percentage of calcium, fibrin, and other cellular waste relative to the percentage of fat and cholesterol. A serrated or scalloped cutter with a serrated cutting edge can facilitate cutting and breaking away calcified and fibrous disease. The serrated edge can advantageously initiate the cut into the calcium by utilizing a large force over a small area, thereby providing the greatest cut efficiency to engage and cut the hardened disease. 
       FIGS.  17 A- 17 B  show an exemplary atherectomy catheter  1700  with a serrated cutter  1703 . The catheter  1700  includes a catheter body  1701  and a nosecone  1705  hinged to the catheter body  1701  at an off-axis hinge point  1709 . As in other embodiments, the nosecone  1709  can be configured to collect tissue therein. In some embodiments, the cutter  1703  can be moved distally to pack tissue into the nosecone. When the nosecone  1705  is deflected, the serrated cutting edge  1710  of the cutter  1703  can be pushed into the tissue. A balloon  1733 , when inflated, can also aid in moving the cutting edge  1710  towards the tissue. 
       FIGS.  18 A- 31 E and  42 A- 42 F  illustrate various embodiments of serrated cutters that can be used, for example, with atherectomy catheter  1700 , to break down calcified and hard fibrous disease in the artery. The serrated cutting edge can spin at a high speed with various serrated geometries configured to engage hard calcified and fibrous disease in the diseased arteries. 
       FIGS.  18 A- 18 E  show a first variation of a serrated cutter  1800  designed for removing calcified plaque. As  FIGS.  18 A- 18 E  show, the serrated cutter  1800  has a proximal end  1802  and a distal end  1804 . The proximal end  1802  is attachable to drive shaft of an atherectomy catheter. The distal end  1804  includes a cutting edge  1810  along the circumference of the serrated cutter  1800  that includes teeth  1812 . The teeth  1812  create saw-like serrations along the edge  1810  that are configured to cut into calcified tissue. Thus, as the cutter  1800  is rotated, the teeth  1812  of the cutting edge  1810  contribute to better purchase and grabbing of calcified deposits for breakage and/or removal of the deposits.  FIG.  18 E  shows the cross-sectional side view of the cutter  1800  attached to a driveshaft  1813 . 
     The serrated cutter  1800  also includes a symmetric and concave or recessed bowl  1814  extending radially inwards from the cutting edge  1810  to the central axis of the cutter  1800 . Further contained within the bowl region is an asymmetric cavity  1816  (i.e., extending off of a central axis of the cutter  1800 ). The asymmetric cavity  1816  covers between ⅓ and ½ of the surface area of the bowl region  1814  of cutter  1800 . The asymmetric cavity  1816 , as shown in  FIG.  18 D , includes three regions that further aid with breaking up of the harder forms of plaque. Further, seams  1815  delineate the three regions of the asymmetric cavity  1816  may protrude slightly above the surface of the asymmetric cavity  1816  walls, where the seams  1815  may be sharp or may include grabbing features that further aid with gripping onto and breaking apart calcified plaque deposits. It is also conceivable that the asymmetric cavity includes greater or less than three regions. As the cutter  1800  is rotated, the asymmetric cavity  1816  advantageously breaks up the calcium plaque within the bowl  1814  as the off-axis sidewalls and/or seams hit the rigid pieces within the bowl  1814 , advantageously avoiding having the calcified plaque fold back onto itself (which can cause stalling of the cutter). 
     Each tooth  1812  of the cutter  1800  borders a grinding segment  1818 . The grinding segments  1818  are depressions or scoops in the bowl  1814  that have a greater curvature than the bowl  1814 . The grinding segments  1818  have a concave curvature at the distal end  1804  of the cutter  1800  (as seen in  FIGS.  18 C and  18 E ). The grinding segments  1818  of the serrated cutter  1800  are largely semi-circular in shape and disposed equidistantly about the perimeter of cutter  1800 . The grinding segments  1818  can have sharp edges or points therearound that are configured to grind, sever, and/or grab onto the calcified plaque by applying more pinpointed force to the calcified plaque encountered while the cutter is rotating. In other variations, the grinding segments  1818  disposed about the circumference of cutter  1800  may be otherwise shaped (e.g. square or rectangular cut outs, triangular cut outs, symmetric, asymmetric, and so forth). Further, the grinding segments  1818  can be either equidistantly disposed about the cutter perimeter or can be more unevenly or non-uniformly disposed about the cutter perimeter. 
       FIGS.  19 A- 19 E  shows drawing of a second variation of a serrated cutter  1900  designed for removing calcified plaque deposits. The serrated cutter  1900  shown in  FIGS.  19 A- 19 E  possess many of the same features as the cutter  1800  shown in  FIGS.  18 A- 18 D , such as a serrated cutting edge  1910  having teeth  1912  and half-circular grinding segment  1918 s disposed evenly along the circumference of the cutting edge  1910 . Similar to the design shown in  FIGS.  18 A- 18 E , the grinding segments  1918  can be depressions within the bowl  1914  that are disposed along the perimeter of the cutter  1910 . The grinding segments  1918  can aid with grabbing and grinding into calcified plaque as the cutter rotates and are able to impart targeted force on the calcified plaque encountered and more easily break off the harder plaque formations. The bowl  1914  is symmetric and recessed in essentially in the shape of a half sphere for accommodating larger plaque formations. In some variations, the bowl region  1914  may also include additional features that can further aid with grabbing and breaking apart calcified plaque as the cutter rotates. Additional features may include protrusions, or cavities about its sidewalls that are either symmetrically or asymmetrically distributed along the wall. The protrusions may have a sharp edge or point while the cavity may have a sharp edge, where these features aid with gaining purchase of the calcified plaque during the procedure. There may also be features at the base of the bowl that aid with gripping and purchase while the serrated cutter is rotating. 
     Another variation of a serrated cutter  2000  for easier debulking of calcified plaque is shown in  FIGS.  20 A- 20 E . The serrated cutter  2000  includes a bowl region  2014  having a serrated cutting edge  2010  disposed along its perimeter. The cutting edge  2010  includes a plurality of teeth  2012  extending therearound with a plurality of grinding segments  2018  therebetween. The grinding segments  2018  can form a deeper scooped portion along the serrated edge  2010 . The grinding segments  1218  can extend radially inwards towards and past the center of the bowl  2014  in an off-axis or spiraled manner. While the scooped grinding segments  2018  are shown in  FIG.  20 D  in a symmetric pattern, as the cutter  2000  rotates, the scooped regions  2018  creates rotational asymmetry within the bowl region  2014  that allows the walls of the grinding segments  2018  to grab onto the plaque and scoop the plaque out and break the plaque up. The combination of the teeth  2012  and the off-axis scoop cuts of the grinding segments  2018  provide enhanced cutting and grinding of calcified plaque as the cutter  2000  rotates. The teeth  2012  and/or grinding segments  2018  may further include edges or seams  2016  that are raised with respect to the surface of the scooped regions  2018  to further aid with gripping the calcified plaque during use. Furthermore, the bowl  2014  and/or the off-axis scooped regions may also include other gripping texture or features that are able to further enhance the purchase of the cutter on plaque deposits encountered during use of the cutter. 
       FIGS.  21 A- 21 E  show another variation of a serrated cutter  2100  that is well-suited for debulking calcified plaque. Serrated cutter  2100  also includes a serrated cutting edge  2110  along the circumference of cutter  2100 . Serrated cutter  2100  also includes a bowl region  2114 . Cutter  2100  further includes a series of teeth  2112  and a series of scooped out grinding regions  2118  that each begin at the cutting edge  2114  and extend inward towards the center of the bowl region  2114 . The edge of the scooped out region  2118  correspond to concave portions along the perimeter of the cutting edge  2110 . As the cutter rotates, the teeth  2112  and the scooped grinding segments  2118  aid greatly with gaining purchase of the calcified regions and providing targeted force onto the calcified plaque. In this example, the series of scooped grinding segments  2118  are arranged in a helical patter within bowl region  2114 . The helical cutting pattern  2118  can advantageous help grab onto plaque and cut the plaque when the cutter is rotating. Cutter  2100  may also include additional features  2116  within the bowl  2114  that increase the cutter&#39;s gripping ability while in use. 
       FIGS.  22 A and  22 B  show a cutter  2200  having no serration along the outer circumference. The cutter  2200 , similar to the other cutters already described, includes a bowl region  2214 . The cutter  2200  has a cutting edge  2210  along its outer perimeter. The cutting edge  2210  is smooth and continuous. Rather than having serrations, cutter  2200  has a series of breaker pockets or grinding segments  2218  distributed along an inner circumference of the bowl region  2214 . Each grinding segment  2218  includes a cavity (having a greater curvature than the bowl  2214 ) for aiding in gripping onto hardened plaque and serve to break up and debulk calcified plaque encountered. The grinding segments  2218  can be in the shape of a circle or an oval. The intersection between the grinding segments  2218  and the areas of the bowl regions  2214  may possess sharpened edges that further aid with gripping and breaking up of hardened plaque. As the cutter  2200  rotates, the grinding segments  2218  can aid with further crushing of the plaque formations and sending these broken down plaque into the nosecone region. While the grinding segments shown in  FIGS.  22 A and  22 B  are symmetric and evenly distributed within the bowl region, in some embodiments, the breaker pockets may be asymmetric in shape and may not all be of the same size. 
     In some instances, hydraulic pressure may be present due to the tight fit between the major, outer diameter of the cutter and the inner diameter of the catheter&#39;s nosecone. Turning to  FIGS.  23 A and  23 B , cutter  2300  includes features that may be able to alleviate some or all of the hydraulic pressure. Like many of the cutters previously discussed, the cutter  2300  includes a bowl region  2314  and a serrated cutting edge  2310  disposed therearound. Here, the teeth  2312  are separated by V-shaped grooves  2323  distributed around the perimeter of the bowl region  2314 . Further, the V-shaped grooves  2323  of cutter  2300  may extend along an outer wall  2320  of cutter  2300  such that where the V-shaped grooves  2318  occur, corresponding V-shaped channels  2319  extend from the V-shaped groove  2323  along the entire length of cutter  2300 ′s outer wall. The V-shaped channels  2319  spaced around the outer wall of cutter  2300  serve to relieve any hydraulic pressure that may be generated in the nose cone when the cutter is slid forward deeper into the nosecone and subsequently when the cutter is drawn back during rotation of the cutter. 
     Turning to  FIGS.  24 A and  24 B , a cutter  2400  is shown. The cutter  2400  includes a bowl region  2414  and a serrated cutting edge  2410  disposed along the perimeter of the bowl region  2414 . The serrated cutting edge  2410  includes a plurality of teeth  2412  separated by shallow cutouts  2423  in the cutting edge  2410 . In this variation of the cutter, the shallow cutouts  2423  extend along an outer wall  2420  of the cutter  2400  to form a rounded channels  2419  that are disposed on the outer wall  2420  of the cutter  2400 . The rounded channels  2419 , similar to the V-shaped channels  2319  described earlier, can serve to relieve hydraulic pressure that may build up while the rotating cutter is pushed into the nosecone of the catheter. 
       FIGS.  25 A and  25 B  shows a cutter  2500 , another variation of cutter designs that include grooves along the outer wall of the cutter. Here, the cutter  2500  includes a bowl region  2514  and a serrated cutting edge  2510  disposed along the perimeter of the bowl region  2514 . The cutting edge  2510  is formed by teeth  2510  separated by v-shaped recesses  2512 . The v-shaped recesses  2523  are asymmetric such that the channels  2519  that are formed from the asymmetric recessed regions  2512  and that extend along an outer wall  2520  of the cutter  2500  are also asymmetric in nature. An advantage of having asymmetric grooves disposed along the outer wall of the cutter is that there is less likelihood that the groove edges from catching on the inner diameter of the nosecone as the cutter is rotating. 
     Another variation of a cutter  2600  is shown in  FIGS.  26 A and  26 B . The cutter  2600  includes a bowl region  2614  and a cutting edge  2610  disposed along the perimeter of the bowl region  2614 . Here, the cutting edge  2610  has a smooth cutting surface about the outer perimeter of the bowl region  2614 . The cutter  2600  further includes angled channels  2619  disposed around the outer wall  2620  of the cutter  2600 . The angled channels  2619  preserves the smooth cutting edge  2610  by originating on the outer wall  2620  of the cutter  2600  just below the cutting edge  2610  and extending away from the smooth cutting edge  2610 . The cutter  2600  may be used in scenarios where the plaque encountered are not of the hardened and calcified variety and where a smooth cutting edge can successfully debulk the plaque encountered. The grooves arranged around the outer wall  2620  are able to minimize the buildup of hydraulic pressure when the cutter is pushed and subsequently pulled back from the catheter nosecone. 
       FIGS.  27 A- 27 E  illustrate another exemplary embodiment of a serrated cutter  2700  having a serrated annular cutting edge  2710 , a recessed bowl  2714 , and a plurality of grinding segments  2718 . The cutter  2700  can include the recessed bowl  2714  extending radially inwards from the annular cutting edge  2710  to a center of the cutter  2700 . The recessed bowl  2714  can extend radially inwards from the cutting edge  2710  with a converge angle. For example, the converge angle of the recessed bowl can be 90 degrees, as shown in  FIG.  27 E . 
     The cutter  2700  can further include a plurality of grinding segments  2718  or dimples within the bowl  2714  and extending radially inwardly from the cutting edge  2710 . The plurality of segments  2718  can each have a substantially circular or ovoid shape. In some other embodiments, the plurality of segments  2718  may be otherwise shaped. Further, each of the plurality of segments  2718  can have a curvature that less than the curvature of the bowl  2714 . As shown in  FIGS.  27 A- 27 D , each of the plurality of grinding segments  2718  can be a flat facet (i.e., such that the curvature is zero and the radius of curvature is infinite). The plurality of grinding segments  2718  can advantageously break the uniformity of the recessed bowl  2714 , thus facilitating breaking hard substances such as calcium. The number of segments can be 2, 3, 4, 5, 6, 8, 12 or any number therebetween. For example, the cutter  2700  can have six grinding segments  2718  as shown in  FIGS.  27 A- 27 E . Further, the plurality of grinding segments  2718  can be either equidistantly disposed about the cutter perimeter or can be more unevenly or non-uniformly disposed about the cutter perimeter. The plurality of segments  2718  can be disposed symmetrically or unsymmetrically around the circumference of the cutting edge  2710 . 
     As shown in  FIGS.  27 A- 27 E , each of the plurality of segments  2718  can form a convex tooth  2712  of the serrated annular cutting edge  2710 . The convex teeth  2712  can be a portion of a circular shape or elliptical shape or other convex shape. The convex shaped teeth  2712  can be advantageous because there no sharp points are formed along a distal-most circumference of the cutting edge  2710 . Since there is a constant force being applied along the arc from cutting tissues, the convex shaped portions are gentle in contact with tissue and have a long cutting length, thus engaging again tissue for a long time. The plurality of convex teeth  2712  can be configured to grind and grab onto the calcified plaque by applying pinpointed force to the calcified plaque encountered while the cutter is rotating. 
     As shown in  FIG.  27 C  and  FIG.  27 E , the serrated annular cutting edge  2710  can angled radially inward relative an outer-most circumference of the cutter  2710  (and/or relative to the elongate body of the catheter to which it is attached). The outer side wall of the cutter edge  2710  on the distal tip  2704  can an angle a relative to a sidewall of the outermost circumference of the cutter  2700  (or of the attached catheter body) along a longitudinal direction. The angle a is advantageous such that the cutting edge  2710  does not cut through the nosecone itself. The angle a can be between 2 to 12 degrees in some embodiments. For example, the angle a can be 5 degrees. The distal tip  2704  of the serrated annular cutting edge  2710  can extend radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. The serrated annular cutting edge  2710  can angled radially and converged to a center axis of the cutter  2700  with a converge angle between 4 degrees and 20 degrees. For example, the converge angle can be 10 degrees in some embodiments as shown in  FIG.  27 E . 
       FIGS.  42 A- 42 F  show another exemplary embodiment of a serrated cutter  82700  designed for removing calcified plaque. Similar to the cutter  2700 , serrated cutter  82700  has a proximal end  82702  configured to attach to a drive shaft of an atherectomy catheter and a distal end  82704 , a serrated annular cutting edge  82710  along the circumference of the distal end  82704 , a recessed bowl  82714 , and a plurality of grinding segments  82718 . 
     The cutter recessed bowl  82714  can extend radially inwards from the annular cutting edge  82710  to a center of the cutter  82700  at a converge angle a (see  FIG.  42 E ). For example, the converge angle a of the recessed bowl can be between 80 and 100 degrees, such as 90 degrees. 
     The grinding segments  82718  can be positioned within the bowl  82714  and extend radially inwardly from the cutting edge  82710 . The grinding segments  82718  can extend radially inwards relative to neighboring portions  82719  so as to form segments that break apart rigid pieces of tissue or plaque as the cutter  82700  spins. The segments  82718  can each have a least one inner edge  82728  that extends substantially straight from the cutting edge  82710  to the center of the cutter  82700 . Thus, the segments  82718  can be squared, rectangular, or trapezoidal. The portions  82719  between the segments  82718  and radially outwards thereof can be, for example, triangular in shape. The plurality of segments  82718  can have the same shape as one another or can have different shapes (e.g., some rectangular and others trapezoidal). Further, the plurality of segments  82718  can extend distally to proximally part or all of the way along the recessed bowl  82714 . For example, the plurality of segments can extend at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or substantially 100% distally to proximally along the bowl  82714  between annular cutting edge  82710  and the recessed flat section  82727 . Each of the plurality of grinding segments  82718  can be a flat facet (i.e., such that the curvature is zero and the radius of curvature is infinite) or can have a curvature (have a “scooped out” configuration). Further, each of the plurality of segments  82718  can have a curvature that is less than the curvature of the bowl  82714 . The plurality of grinding segments  82718  can advantageously break the uniformity of the recessed bowl  82714 , thus facilitating breaking hard substances such as calcium. The bowl  82714  can have  2 - 16  grinding segments  82718  therein, such as 2, 3, 4, 5, 6, 8, or 12 grinding segments  82718 . For example, the cutter  82700  can have six grinding segments  82718  as shown in  FIG.  42 D . Having fewer grinding segments may, for example, make the recessed bowl easier to manufacture while having more may better distribute the load as the cutter rotates and cuts material. Further, the plurality of grinding segments  82718  can be either equidistantly disposed about the cutter perimeter or can be more unevenly or non-uniformly disposed about the cutter perimeter. The plurality of segments  82718  can be disposed symmetrically or unsymmetrically around the circumference of the cutting edge  82710 . 
     As shown in  FIGS.  42 A- 42 F , each of the plurality of segments  82718  can form a convex tooth  82712  of the serrated annular cutting edge  82710  while the neighboring portions  82719  therebetween can form a concave section  82721  therebetween. The convex teeth  82712  can be a portion of a circular shape or elliptical shape or other convex shape. The convex teeth  82712  and concave section  82721  can form an undulated or wavy cutting edge  82710  (e.g., by a continuous wave of scallops). The undulating cutting edge  82710  can be advantageous because there are no sharp points along a distal-most circumference of the cutting edge  82710 , thereby allowing the edge  82710  to last longer without wearing down. Additionally, the entire undulating cutting edge  82710  can contact tissue as the cutter  82700  is rotated, thereby providing sharper cutting through the tissue or plaque. The proximal edge  82723  formed by the segments  82718  and neighboring portions can have a similar undulating shape. 
     The plurality of convex teeth  82712  and grinding segments  82718  can be configured to grind and grab onto the calcified plaque by applying pinpointed force to the calcified plaque encountered while the cutter is rotating. 
     As shown in  FIG.  42 F , the serrated annular cutting edge  82710  can be angled radially inward relative an outer-most circumference of the cutter  82710  (and/or relative to the elongate body of the catheter to which it is attached). The outer side wall of the cutter edge  82710  on the distal tip  82704  can extend inwards at an angle f 3  relative to a sidewall of the outermost circumference of the cutter  82700  (or of the attached catheter body) along a longitudinal direction. The angle β is advantageous such that the cutting edge  82710  does not cut through the distal end of the catheter (e.g., the nosecone). The angle β can be between 2 to 12 degrees in some embodiments. For example, the angle β can be 5 degrees. 
     The recessed bowl  82714  can further including a flat (i.e., not curved) circular section  82727  at the proximal end of the recessed bowl thereof that is recessed relative to the proximal undulating edge  82723  formed by the grinding segments  82718  and neighboring portions  2719 . 
       FIG.  28 A- 28 E  illustrate another embodiment of a serrated cutter  2800  having a serrated annular cutting edge  2810 , a recessed bowl  2814 , and a plurality of grinding segments  2818 . The serrated annular cutting edge  2810  can have a plurality of teeth  2812 . As shown in  FIGS.  28 A- 28 E , each of the plurality of segments  2818  can form concave edges between the teeth  2812  of the serrated annular cutting edge  2810 . The curvature of the grinding segments  1818  can be greater than the curvature of the bowl  2814 , thereby forming depressions or cavities in the bowl  2814 . The number of segments can be 2, 3, 4, 5, 6, 8, 12 or any numbers therebetween. For example, the cutter  2800  can have seven recessed grinding segments  2818  as shown in  FIGS.  28 A- 28 E . Further, the plurality of grinding segments  2818  can be either equidistantly disposed about the cutter perimeter, as shown, or can be more unevenly or non-uniformly disposed about the cutter perimeter. The plurality of segments  2818  can be disposed symmetrically, as shown, or unsymmetrically around the circumference of the cutting edge  2810 . 
     As shown in  FIG.  28 C , the serrated annular cutting edge  2810  can be angled radially inward relative an outer diameter of the cutter  2800  (and/or the elongate body of the catheter). The outer side wall of the cutter edge  2810  forms an angle β relative to a sidewall of the elongate body of the catheter  2800  along a longitudinal direction. The angle β can be between 2 to 12 degrees in some embodiments. For example, the angle β can be 5 degrees. The distal tip of the serrated annular cutting edge  2810  can extend radially inward relative an outer diameter of the elongate body by 2 degrees to 12 degrees. The angle β advantageously ensures that the cutting edge  2810  does not cut through the distal tip or nosecone of the catheter. The serrated annular cutting edge  2810  can be angled radially and converged to a center axis of the cutter  2800  with a converge angle between  4  degrees and  20  degrees. For example, the converge angle can be  10  degrees in some embodiments as shown in  FIG.  28 E . 
       FIGS.  29 A- 29 E  illustrate a cutter  2900  including a serrated annular cutting edge  2910  with teeth  2912  and a recessed bowl  2914 . The atherectomy cutter  2900  can be similar to the cutter  2800  except that the cutter can include five grinding segments  2918  rather than seven. Further, each of the segments  2918  can be longer, e.g., extend a greater distance along the circumference of the cutting edge  2910 , than in cutter  2800 . 
       FIGS.  30 A- 30 E  illustrate a cutter  3000  including a serrated annular cutting edge  3010  with teeth  3012  and a recessed bowl  3014 . The cutter  3000  can be similar to cutters  2800  and  2900  except that the cutter can include ten grinding segments  3018 . The grinding segments  3018  can form a substantially half-circle shape. 
       FIGS.  31 A- 31 E  illustrate a cutter  3100 . The cutter  3100  can be similar to cutter  3000  except that the grinding segments  3118  can be further closer to one another, thereby making the teeth  3112  shorter. For example, the cutting edge of each tooth  3112  of cutter  3100  can be approximately 0.1-0.3, such as approximately 0.25, of the length of cutting edge of each grinding segment  3118 . In contrast, the cutting edge of each tooth  3012  can be approximately 0.4-0.6, such as 0.5 of the length of the cutting edge of each grinding segment  3018 . In some embodiments, the cutter  3100  can also be smaller in size overall (e.g., be configured to sit within a 7 French catheter) than the cutter  3000  (which can be configured, for example, to sit within an 8 French catheter). 
     The cutters described herein can be used, for example, for above the knee atherectomy procedures. In such embodiments, the cutter can be designed to fit in an 8 French catheter and thus can have a diameter, for example, of between 0.07 inches and 0.9 inches, such as approximately 0.077 inches. The cutters described herein can also be used, for example, for below the knee atherectomy procedures. In such embodiments, the cutter can be designed to fit in a 7 French catheter and can have a diameter, for example, of between 0.05 inches and 0.07 inches, such as approximately 0.065 inches. The recessed bowl in the cutters described herein can advantageously help collect and push cut tissue or plaque into the collection chamber in the nosecone of the atherectomy device. 
     The cutters described can be useful for gripping on to and breaking apart calcified plaque deposits found within the arteries as well as softer forms of plaque that may be encountered. Because calcified plaque is much harder than its softer plaque counterparts, repeated use of the cutter for breakoff and clearing calcified plaque can easily lead to dull cutting edges that are less proficient at grabbing onto and breaking off calcified plaque during subsequent use. Thus, in some examples of the serrated cutter, the cutting edge or even the entire cutter region, including the cutting edge and the bowl, may be coated with or dipped in a hardening material. Suitable hardening coatings may include carbon composites such as tungsten carbide, graphene, and so forth. While the cutters described herein are shown with specific features, it is conceivable that different features from the different cutters described may be combined to form cutters having feature combinations that have not been specifically described herein. 
     In some embodiments, the cutters serrated cutters described herein can be configured to be interchangeable with one another and/or with non-serrated cutter so as to allow the operator to vary the aggressiveness of the cutter during use. 
     It should be understood that any feature of one embodiment of a cutter described herein can be added, removed, and/or combined with other embodiments. 
     Advantageously, the atherectomy catheters described herein can be used to remove strips of tissue and/or to remove hard or calcified tissue.  FIG.  13 A  shows the removal of a single, long strip of material cut from the tissue by an atherectomy catheter as described herein.  FIGS.  13 B and  13 C  show the length of tissue (weighting  70 . 4  mg) removed. 
     The atherectomy catheters described herein may additionally include any of the features described in the following co-pending applications: PCT Application No. PCT/US2013/031901, entitled “ATHERECTOMY CATHERES WITH IMAGING,” and filed Mar. 15, 2013, and PCT Application No. PCT/US2013/032494, entitled “BALLOON ATHERECTOMY CATHERS WITH IMAGING” and filed Mar. 15, 2013, and PCT Application No. PCT/US17/22780, entitled “ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES” and filed Mar. 16, 2017, all of which are incorporated by reference herein in their entireties. 
     The catheters described herein can be driven using a drive assembly. Exemplary drive assemblies are described in co-pending Patent Applications: PCT Application No. 
     PCT/US13/32089, entitled “ATHERECTOMY CATHETER DRIVE ASSEMBLIES,” filed Mar. 15, 2013, and U.S. patent application Ser. No. 13/654,357, titled “ATHERECTOMY CATHETERS AND NON-CONTACT ACTUATION MECHANISM FOR CATHETERS,” filed Oct. 17, 2012, both of which are incorporated by reference in their entireties. 
     Also described herein are support arms for maintaining and positioning a medical device component, such as a controller or drive assembly of an atherectomy catheter, during related medical procedures. In particular, the support arm is able to attach easily to any rail in close proximity to the procedure table and to take multiple positions for providing convenient access to a catheter (e.g., atherectomy catheter) control unit. 
     An exemplary support arm assembly  9100  is shown in  FIGS.  32 A- 32 C . In general, the support arm assembly  9100  can include a clamp  9110 , a support arm  9130  and a device mount  9150 . In some embodiments, the assembly  9100  can also include a cable retainer  9170 . The support arm  9130  has two ends. The clamp  9110  couples to one end of the support arm  9130 , and the device mount  9150  couples to the other end. 
     The support arm  9130  may be releaseably attached to clamp  9110 . Support arm  9130  may swivel up to  9360  degrees with respect to clamp  9110 . This allows the support arm  9130  to be easily positioned anywhere along the length of an operating or procedure table. The support arm  9130  may also be adjusted so that it can reach the width of any operating or procedure table. In use, the free end of the support arm  9130  is coupled to the device mount  9150 . The free end of the support arm  9130  can allow for rotational freedom of the coupled device mount  9150  such that the device component being held by the device mount  9150  may be arranged in the most optimal position during a procedure. 
     As shown in  FIG.  32 B , the support arm  9130  can include two segments  9134  and  9139  joined by a segment joint  9135 . While  FIG.  32 B  shows segments  9134  and  9139  as being cuboid in shape, the segments can be any reasonable geometric shape, such as hexagonal or triangular prism, a cylindrical rod, and so forth. As shown in  FIGS.  32 A- 32 C , the segment joint  9135  provides a hinged connection between segment  9134  and segment  9139 . The segment joint  9135 , as shown, provides freedom to move along one axis. In other examples, the segment joint may be a joint that provides greater degrees of freedom such that one segment is able to rotate out of axis relative to the second segment. 
     Each segment  9134  and  9139  can include segment free ends  9137  and  9138 . At segment free end  9137  is a clamp arm joint  9132 . A clamp arm joint  9132  couples with the segment free end  9137  of segment  9134 . Disposed on the clamp arm joint  9132  is a clamp coupling post  9131  for coupling to clamp  9110 . In the figures, the clamp arm joint  9132  that joins clamp coupling post  9131  with segment  9134  is a hinged connection that allows for movement of the segment  9134  relative to the clamp coupling post  9131  in a fixed axis of rotation. In other examples, the coupling joint that connects one segment to the clamp coupling post may be a rotatable joint that is able to have multiple degrees of rotational freedom. 
     Disposed at the segment free end  9138  can be a device mount coupler  9142  that couples the segment  9139  to the device mount  9150 . The device mount coupler  9142  shown in  FIG.  32 B  is configured to rotate along one axis, but in other examples, the device mount coupler  9142  may rotate along multiple axes. The device mount coupler  9142  also includes a device mount adjustor  9143 . The device mount adjustor  9143  is able to loosen or tighten the device mount coupler  9142  for positioning the device mount  9150  and maintaining the device mount  9150  once a desired position has been found. 
     The support arm  9130  can also include friction adjustors  9133  and  9136 . In some embodiments, the friction adjustors  9133  and  9136  can be identical. An exemplary embodiment of a friction adjustor  9233  (which can be used as a friction adjustor  9133  and/or  9136 ) is shown in  FIGS.  33 A- 33 B . The friction adjustor  9233  can each include an adjustment knob screw  9140  and an adjustment knob handle  9141 . The adjustment knob handle  9141  is shown as having a rod-like structure of approximately  3 . 5  inches in length, but in other examples, the adjustment knob handle may be of either shorter or longer length and may be of other suitable shape such as a flat piece of material or a rod having various cross-sectional dimensions. The adjustment knob screw  9140  includes a screw portion  9144  at one end and a handle coupler  9145  at its opposing end joined by an adjustment knob screw stem  9146 . The handle coupler  9145  as shown further includes a handle coupling aperture  9148  into which the adjustment knob handle  9141  may be inserted. While the figures show the adjustment knob handle  9141  as having a circular cross-section and the handle coupler aperture  9148  having a corresponding circular opening, it is possible for the adjustment knob handle to have any cross-sectional dimension and for the handle coupling aperture to have a corresponding aperture opening shape to accommodate the adjustment knob handle. In use, once the operator has positioned the support arm  9130  into a desired position, the operator may turn the adjustment knob handle  9141  such that the screw portion  9144  bears down on either the segment joint  9135  or the clamp arm joint  9132 , locking the segments into a fixed position. The adjustment knob handle  9141  may be turned to loosen and reduce the amount of force that the screw portion  9144  of the adjustment knob screw  9140  applies to either the segment joint  9135  or the clamp arm joint  9132 . 
     While  FIGS.  32 A- 32 C  show the support arm segments as having approximately equal length, the segments may of differing length. In other examples, the support arm may include more than two segments or include many segments such that the medical device component may be more easily maneuvered or maneuvered with greater precision. In yet other examples, the support arm segments may have telescoping qualities such that each segment may be lengthened or shortened depending on the position desired. 
     Moreover, while  FIGS.  32 A- 32 C  show a knob type adjustment for adjusting and maintaining the support arm segments, other types of adjustment units may also be used. These may include a flip type locking mechanism, a ratchetting system, or other type locking mechanism known in the art that is integrated into the body of the coupled segments. 
     Referring still to  FIGS.  32 A- 32 C , the clamp  9110  can be configured to couple the assembly  9100  to a bed rail or other solid support. The clamp  9110  can thus be configured to provide enough support and stability to hold both the support arm  9130  and a medical component coupled to the device mount  9150  steady during a procedure. As such, the clamp  9110  can be designed so as to withstand the weight of the support arm  9130 , the device mount  9150 , and the medical device within the mount  9150  even as the arm  9130  is maneuvered around. In some embodiments, the clamp  9110  securely attaches to a rail or other solid support when the medical device within the mount  9150  is greater than 5 pounds, greater than 10 pounds, or greater than 15 pounds, such as up to approximately 20 pounds. The clamp  9110  can be easy to adjust such that, with a single motion, a user is able to attach or release the clamp  9110  from a rail or a solid surface or support. In some embodiments, the clamp  9110  has an adjustable diameter of between 0.5 inch and 3 inches. 
     As shown in  FIGS.  32 A and  32 B , the clamp  9110  can be coupled to the support arm  9130  through the clamp coupling post  9131 . An exemplary embodiment of a clamp  9310  (which can be used as claim  9110 ) is shown in  FIGS.  34 A- 34 E . The clamp  9310  includes a clamp top jaw  9114 , a clamp top cover  9111 , a clamp bottom jaw  9120 , and a clamp lever  9116 . The jaws  9114 ,  9120  can be configured to move towards one another to clamp a device therebetween. The clamp top cover  9111  can include a support arm coupler  9112  and a cutout region  9117 , both of which are disposed on the top surface of the clamp top cover  9111 . The support arm coupler  9112  can further include a support arm coupling aperture  9113  that may be mated with the clamp coupling post  9131 . The support arm coupler  9112  may also include sleeve bearings  9119  to provide better rotational movement by reducing friction between the clamp coupling post  9131  and the support arm coupler  9112 . There may also be screws  9333  for retaining the sleeve bearings  9119  in place. The cutout region  9117  can be positioned opposite the support arm coupler  9112 . The top piece cutout region  9117  can function to retain a course adjustment knob  9118 . 
     In use, the distance between the clamp upper jaw  9114  and the clamp lower jaw  9120  may be adjusted to retain various sizes of rail or surface. Distances between the upper jaw  9114  and the lower jaw  9120  may range from 0.5-3 inches. In some embodiments, the operator may turn the course adjustment knob  9118  when it is coupled to the clamp  9110  to adjust the initial distance between the top jaw  9114  and the bottom jaw  9120 . 
     In some embodiments, a lever  9116  can be configured to allow for vertical movement of the clamp lower jaw  9120 . The lever  9116  includes a lever handle  9123  and a lever stem  9124 . By toggling the lever handle  9123  from one side to another and back, the operator may adjust the distance between the clamp upper jaw  9114  and the clamp lower jaw  9120 . The lever  9116  is in a shape that allows easy adjustment of the distance between the upper and lower jaws  9114 ,  9120  of the clamp  9110 . The lever  9116  includes a lever stem  9124  that mates with a side cam lever adjustor  9122 . The lever  9116  also includes a lever stem cutout  9125  that may be used to retain a post or dowel  9127  that allows for coupling to the side cam lever adjustor  9122 . The side cam lever adjustor  9122  includes a side cam lever adjustor aperture  9126  that couples to lever stem  9124 . Furthermore the side cam lever adjustor aperture  9126  may further include a side cam lever adjustor aperture cutout  9128  that serves to more precisely mate with the lever stem cutout  9125  of lever  9116  through the dowel  9127  such that when the lever handle  9123  of lever  9116  is moved from one side to the other, the dowel  9127  is moved within the side cam lever adjustor aperture cutout  9128  and through the clamp bottom piece aperture  9121  to move the bottom jaw piece  9115  up and down. The side cam lever adjustor  9122  may also include side cam lever adjustor coupling apertures  9129  for coupling to the upper jaw  9114  and the lower jaw  9120  pieces. The joining of the lever  9116  with the bottom jaw piece  9115  through the side cam lever adjustor  9122  may also include washers for cushioning the movement of the lever with respect to the side cam lever adjustor. The claim  9310  may also include a spring  9331  to provide a more even force distribution against the bottom jaw piece  9115  when actuated by the side cam lever adjustor  9122 . The lever  9116 , side cam lever adjustor  9122 , and clamp lower jaw  9120  ensemble may further include other dowels, screws, and pins to provide smooth actuation of the clamp lower jaw  9120  when the lever  9116  is adjusted. 
     An alternative clamp design  9610  (that could be used as clamp  9110 ) is shown in  FIGS.  37 A- 37 B . The clamp  9610  functions in essentially the same manner as clamp  9210  for grabbing onto a rail or a surface. The primary difference between the clamps  9610  and  9210  is that in clamp  9610 , a lever  9616  that actuates a lower jaw  9620  (to bring it closer to the upper jaw  9614 ) can be flipped from an up and down direction, while clamp  9210  actuates the clamp with a side to side motion of its lever. 
     Referring back to  FIGS.  32 A- 32 C , cable retainers  9170  (or clasps) can be used to maintain cables used for powering the medical device such that the cables do not become entangled. The cable retainers  9170  can also keep the cables away from the patient and/or prevent the cables from needlessly obstructing the medical personnel&#39;s view of the patient or treatment site during a procedure. As can be seen from  FIGS.  32 A and  32 B , the series of cable management retainers  9170  may be disposed along the length of segments  9134  and  9139 . The cable management retainers  9170  can be constructed to comfortably retain cables associated with the use of the medical device (e.g. power cables, signal cables, wires, and so forth). The cable management retainers  9170  can keep necessary cables associated with the medical device component clear of where healthcare professionals may be working. 
     An exemplary cable management retainers  9470  (which can be used as retainer  9170 ) is shown in  FIGS.  35 A- 35 C . The cable management retainer  9470  includes a cable management top cover  9171  coupled with a cable management bottom piece  9175 . The cable management top cover  9171  includes a cable management top coupling channel  9172  that is capable of accepting a pin  9179 . The cable management top cover  9171  also includes a cable management torsion spring groove  9173  that is able to mate with a torsion spring  9180 . When in place, the torsion spring  9180  allows the cable management top cover  9171  to automatically snap back to a closed position after the cable management top cover  9171  has been flipped to an open position. 
     This prevents cables or wires from inadvertently slipping out of the cable management retainer  9470  during the medical procedure and interfering with the medical procedure at hand. 
     The cable management bottom piece  9175  includes at least two cable management bottom channels  9176  such that when the cable management top coupling channel is seated between the two cable management bottom channels  9176  and a pin  9179  is inserted through the each of the channels, the cable management top cover  9171  mates with the cable management bottom piece  9175  and is able to pivot at with respect to the cable management bottom piece  9175 . The cable management bottom piece  9175  further includes a cable management bottom lip  9177 . The cable management bottom lip  9177  has a slanted outer edge such that when the cable management top cover  9171  is in contact with the cable management bottom piece  9175 , the slanted outer edge comes into contact with the shorter side of the tapered edge of the cable management top cover  9171 . The cable management top cover  9171  can also be slightly tapered underneath. The advantage of this configuration is that a user can easily catch the longer side of the tapered edge of the cable management top cover  9171  with his finger and easily insert or remove cables of choice, even if wearing gloves. The cable management bottom piece  9175  also includes at least one cable management bottom screw aperture  9178 , which allows the cable management clasp  9170  to be coupled to the support arm  9130  or other portion of the support arm assembly  9100 . 
     Referring back to  FIGS.  32 A- 32 C , the device mount  9150  can be configured to couple with, and hold steady, a medical device component that is greater than 5 pounds, greater than 10 pounds, or greater than 15 pounds, such as up to 20 pounds. For example, the device mount  9150  can be configured to maintain a catheter drive controller during use of the catheter (e.g., an atherectomy catheter). 
     An exemplary device mount  9550  (which can be used as device mount  9150 ) is shown in  FIGS.  36 A- 36 B . The device mount  9550  includes a device mount stem  9151 . At one end of the device mount stem  9151 , a device mount base  9152  is attached. The device mount base  9152  extends perpendicularly away from the device mount stem  9151 . Disposed on the end of the device mount base  9152  opposite where it couples to the device mount stem  9151 , is a device mount post  9154  that extends in the direction of the device mount stem  9151 . The device mount stem  9151  may include coupling pin apertures  9164  for coupling to the device mount base  9152  and the device mount latch  9153 . 
     In the embodiment of the device mount  9550 , the device mount base  9152  also includes a device mount base stem aperture  9160  for coupling to the device mount stem  9151  and a device mount base post aperture  9161  that couples to the device mount post  9154 . The device mount post  9154  is configured to couple with the device component being supported so as to prevent the device component from detaching form the device mount  9550  during use and inadvertently injuring the patient. The device mount base  9152  may also include coupling pin apertures  9164  that may be tightened or loosened for either coupling to the device mount stem  9151  or the device mount post  9154 . 
     The device mount  9550  also includes a device mount latch  9153  at an intermediate position along the device mount stem  9151 . The device mount latch includes a device mount latch stem aperture  9162  for coupling to the device mount stem  9151 . The device mount latch  9153  may be adjusted along the device mount stem  9151  such that when a device has been coupled to the device mount post  9154 , the device mount latch  9153  may be lowered to contact the top surface of the device component, where then the device mount post  9154  may be tightened locking its position along the length of device mount stem  9151  for steadying the device component within device mount  9550 . In some instances, the device component having a corresponding cavity for accepting the device mount post  9154  may be swiveled to obtain the best viewing angle. Once the desired orientation of the device component has been obtained, the device mount latch may be used to maintain the orientation of the device component during use. While not shown the device mount latch may include a cushioning layer on its surfaces that come into contact with the device component. 
     The end of the device mount stem  9151  that is configured to couple to the device mount adjustor  9143  of the support arm  9130  includes a device mount stem notch  9155 . The device mount stem notch  9155  encompasses the entire circumference of the device mount stem  9151 . The device mount stem notch  9155  allows the device mount  9150  to be snapped into, and held within, the device mount coupler  9142 . The device mount coupler  9142  may have include internal mechanisms (not shown) that allow it to grip onto the device mount stem notch  9155  of the device mount  9150 . The device mount  9550 , when coupled to the support arm  9130 , can rotate along at least one axis of rotation. The device mount  9150  is able to rotate about the long axis of the device mount stem  9151 . In other examples, the device mount stem  9151  may be coupled to the device mount coupler  9142  by any suitable means known in the art including but not limited to hooks, clasps, clips, and so forth. 
       FIG.  36 C  shows the device mount  9550  attached to a controller  9666 , e.g., a controller for an atherectomy catheter. The device mount  9154  can mate with a slot in the controller  9666 , and the controller  9666  can rest on the base  9152 . The device mount latch  9153  can help maintain the controller  9666  within the device mount  9550 . The device mount post  9154  height may range anywhere from approximately  1 cm to  3 cm. The device mount post  9154  advantageously does not interfere with the circuitry, layout, or function of the device component. The device mount  9550  is designed such that their weight when coupled to the device component provides reasonable counter weight to the support arm  9130  and thus does not over-stress the coupling between the clamp  9110  and its supporting element (e.g. bed rail). In some other examples, the device mount may include some other type of coupling mechanism. For example, the device mount base may include one or more protrusions or locking mechanism that are able to mate with features on the device component. The device mount base may include adjustable appendages that can grasp onto the device component or snap onto the device component. The device mount may include female couplers that are able to make with corresponding male couplers on the device component or vice versa. 
       FIG.  38    shows another embodiment of a device mount  9750 . Instead of a device mount latch as that of device mount  9550 , the device mount  9750  is in a “C” configuration, where the top portion includes a device mount flap  9253  and the bottom portion has a device mount support base  9252  that is able to support the dimensions of the device component instead of coupling to the device component through a single attachment point. The device mount flap  9253  may be adjustable in distance with respect to the device mount support base  9252 . The device mount flap  9253  may be hingedly attached to the device mount support base  9252  such that it is able to hold the device component securely during use. It may also be possible for the device mount flap  9253  and the device mount support base  9252  to rotate about the longitudinal axis of a device mount post  9254 . 
     Further,  FIGS.  39 A- 39 B  show another embodiment of a device mount  9850 . The device mount  9850  includes a base against which the controller  9866  sits. A device mount post  9854  can be configured to be rotated or screwed into a mating hole in the controller  9866  to hold it thereto. 
       FIGS.  40 A- 40 C  show yet another embodiment of a device mount  9950 .  FIGS.  40 A- 40 B  shows a device mount  9350  that is unattached, and  FIG.  40 C  shows the device mount  9250  securely attached to a controller  9966 . Similar to the device mount  9750 , device mount  9950  has a “C”-shaped configuration with a device mount post  9354  for coupling to the support arm. The device mount  9350  has an outer C holder  9357  and an inner C clasp  9358 . The inner C clasp  9358  may hingedly hold onto the device component during use. The distance between the two ends of the C clasp  9358  may also be adjusted to accommodate different device component heights. 
     Another exemplary device mount  91050  is shown in  FIGS.  41 A- 41 B . The device mount  91050  can be attached to a pivotable portion  91092  of a support arm  91000 . Further, the device mount  91050  can include a base  91052  configured to sit horizontal such that the controller  91066  can rest thereon. Device mount posts  91054   a,b  can be configured to mate with corresponding apertures on the controller  91066  to hold it in place. 
     The device mounts, support arm assemblies, and clamping mechanisms described herein can all be designed to be able to balance the weight of the device component being held such that the clamp is able to maintain secure contact with the rail or surface onto which it is clamped. 
     The devices described herein may include additional features not shown in the figures. For example, the device mount flap and/or the device mount support base may include cushioning material on the surfaces that would contact the device component. In other instances, the device mount portions that would contact the device component may include materials having greater friction so that the device component would not easily slip from the device mount while being maneuvered. Device mounts described herein may also include springs known in the art of clips and clamps that aid with maintaining pressure on the device component during use. 
     As noted above, the devices and techniques described herein can be used with OCT imaging. Exemplary imaging systems are described in co-pending applications: U.S. patent application Ser. No. 12/790,703, titled “OPTICAL COHERENCE TOMOGRAPHY FOR BIOLOGICAL IMAGING,” filed May 28, 2010, Publication No. US-2010-0305452-A1; U.S. patent application Ser. No. 12/829,267, titled “CATHETER- BASED OFF-AXIS OPTICAL COHERENCE TOMOGRAPHY IMAGING SYSTEM,” filed Jul. 1, 2010, Publication No. US-2010-0021926-A1; International Patent Application titled “OPTICAL COHERENCE TOMOGRAPHY WITH GRADED INDEX FIBER FOR BIOLOGICAL IMAGING,” filed Mar. 15, 2013, Publication No. WO-2013-172972, all of which are incorporated by reference in their entireties. 
     When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature. 
     Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”. 
     Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise. 
     Although the terms “first” and “second” may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention. 
     Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps. 
     As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. 
     Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims. 
     The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. 
     Additional details pertinent to the present invention, including materials and manufacturing techniques, may be employed as within the level of those with skill in the relevant art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts commonly or logically employed. Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein. Likewise, reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “and,” “said,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Unless defined otherwise herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The breadth of the present invention is not to be limited by the examples described herein, but only by the plain meaning of the claim terms employed.