Abstract:
Provided is a surgical handpiece for providing an electromagnetic cutting blade. The handpiece, comprises a body portion having an input end and an output end, a plurality of optical fibers for receiving laser energy having a wavelength within a predetermined wavelength range, wherein the optical fibers are received in the body portion at the input end and extend to the output end, and an optical fiber transition region within the body portion for arranging the plurality of optical fibers into a predetermine cutting shape at the output end, wherein laser energy transmitted from the arranged optical fibers at the output end interact with water molecules near the surgical target to generate micro-explosions that result in a cutting effect.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/542,712, filed Oct. 3, 2011, the entire contents of which are hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The technology described herein relates generally to medical lasers and, more particularly, to surgical applications of medical lasers. 
       BACKGROUND 
       [0003]    Surgical instruments typically employed in applications such as orthopedics and oral surgery, in the ablation or cutting of hard tissue or bone, include high speed oscillating saws, manual saws or chisels. For example, depicted in  FIG. 1  is an oscillating saw that may be operated by hand or that may be caused to vibrate by a motor in order to cut through a relatively large bone. A handle  10  has a cutting blade  20  disposed at the end of the handle. A sawing motion perpendicular to a direction of travel  30  can be used to saw through bone tissue  40 . Devices such as these produce a cutting effect using friction. Friction, however, produces heat and the heat can cause the death of cells near the cut zone due to thermal necrosis. 
       SUMMARY 
       [0004]    In accordance with the teachings provided herein, a surgical handpiece for providing an electromagnetic cutting blade is disclosed. The handpiece, comprises a body portion having an input end and an output end, a plurality of optical fibers for receiving laser energy having a wavelength within a predetermined wavelength range, wherein the optical fibers are received in the body portion at the input end and extend to the output end, and an optical fiber transition region within the body portion for arranging the plurality of optical fibers into a predetermine cutting shape at the output end, wherein laser energy transmitted from the arranged optical fibers at the output end react with fluid molecules near the surgical target to generate micro-explosions that result in a cutting effect. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Depicted in  FIG. 1  is an oscillating saw that may be operated by hand or that may be caused to vibrate by a motor in order to cut through a relatively large bone; 
           [0006]    Depicted in  FIG. 2  is an example laser handpiece device  100  that can be used for cutting bone or other hard biological material; 
           [0007]    Depicted in  FIG. 3A  is a side view of an example laser handpiece device  100 ; 
           [0008]    Depicted in  FIG. 3B  is a top view of the example laser handpiece device  100 ; 
           [0009]    Depicted in  FIG. 3C  is a view of an example handpiece having a cylindrical shape; 
           [0010]    Depicted in  FIG. 4A  is a view of the transition region  120 ; 
           [0011]    Depicted in  FIG. 4B  is an example housing  126  for fanning out the optical fibers; 
           [0012]    Depicted in  FIG. 5A  is an example system for dispersing collimated light  132  from a collimated laser source to the individual optical fibers that enter the handheld device; 
           [0013]    Depicted in  FIGS. 5B-5D  are example control signals for controlling the scan rate of mirror  134 ; 
           [0014]      FIG. 6A  illustrates that electromagnetic energy  140  dispensed from an example handpiece  142  may be collimated and therefore will spread slowly as it propagates toward a cut zone  144  at a surgical target  146 ; 
           [0015]    Depicted in  FIG. 6B  are various tips that may be applied to the end  148  of handpiece  142  to cause more spreading of the electromagnetic energy as it is dispensed to create a wider or thicker cut zone; 
           [0016]    Depicted in  FIG. 7A  is an example handpiece  158  having a fluid inlet  160  and a gas inlet  162 ; 
           [0017]      FIG. 7B  illustrates example locations for water outlets  164  in a handpiece; 
           [0018]    Depicted in  FIGS. 8A-8F  are example arrangements of the optical fibers at the output end of a handpiece; and 
           [0019]      FIGS. 9A-9C  illustrates an example of sectioning the crown of the tooth for crown preparation. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Depicted in  FIG. 2  is an example laser handpiece device  100  that can be used for cutting bone, tooth or other hard biological material. The handpiece  100  is an electromagnetic delivery device that functions as an electromagnetically induced disruptive cutter. The handpiece  100  directs electromagnetic energy  102  in the form of beams of laser energy into an interaction zone in close proximity to a surgical target  104  such as a bone, tooth, or other hard biological material. Fluid particles  106  such as water particles are also directed to the interaction zone. 
         [0021]    The laser energy  102  interacts with fluid particles  106  in the interaction zone and with water molecules contained within the biological target. The laser energy is absorbed by and excites the fluid particles  106  and the water molecules resulting in sequential micro-explosions of the fluid particle and water molecules. These micro-explosions generate mechanical disruptive forces. The disruptive forces when applied to the biological target result in a cutting effect on the surface of the target. 
         [0022]    The laser energy  102  is at a wavelength and energy level sufficient to excite micro-explosions in water molecules but not at levels sufficient to damage biological tissue. In the example system, typical values for total laser energy (energy emitted by all fibers) per laser pulse may range from about 0.05 J to about 2.0 J, and the energy may be generated with a wavelength ranging from about 2.75 μm to about 3.00 μm. 
         [0023]    The fluid particles injected into the interaction zone perform a number of purposes. Some of the fluid particles absorb beams of light, explode, and impart a mechanical disruptive force to the target. Remaining portions of the fluid particles reduce the temperature surrounding the explosion so that living cells adjacent the target area will not be exposed to the extreme heat resulting in cell necrosis and death. 
         [0024]    Very efficient tissue cutting without adjacent cells necrosis can be achieved using this technology. In the example system, individual beams are arranged parallel to each other in the same plane creating a linear segment of beams at a target that are sequential fired. This reduces the likelihood of a manual sweeping action being used to cut through tissue resulting in an efficient and accurately sized cut. 
         [0025]    The handpiece  100  is coupled to an electromagnetic energy source  108  (i.e., laser energy source) which generates laser energy. The electromagnetic energy source  108  may include devices comprising mirrors, lenses, and other optical components for collimating and focusing generated laser energy. The generated laser energy is delivered to the handpiece  100  via a plurality of optical fibers  110  which extend into the interior of the handpiece  100 . 
         [0026]    The electromagnetic energy source  108  may include a variety of different lasers or other sources of light. The electromagnetic energy source  108  may use an erbium, chromium, yttrium, scandium, gallium garnet (Er, Cr:YSGG) solid state laser, which generates light having a wavelength in a range of approximately 2.70 to 2.80 μm. Laser systems used in other examples include an erbium, yttrium, aluminum garnet (Er:YAG) solid state laser, which generates radiation having a wavelength of 2.94 μm; a chromium, thulium, erbium, yttrium, aluminum garnet (CTE:YAG) solid state laser, which generates radiation having a wavelength of 2.69 μm; an erbium, yttrium orthoaluminate (Er:YAL03) solid state laser, which generates radiation having a wavelength in a range of approximately 2.71 to 2.86 μm; a holmium, yttrium, aluminum garnet (Ho:YAG) solid state laser, which generates radiation having a wavelength of 2.10 μm; a quadrupled neodymium, yttrium, aluminum garnet (quadrupled Nd:YAG) solid state laser, which generates radiation having a wavelength of 266 nm; excimer lasers, which generates radiation having a wavelength of 193-308 nm; a carbon dioxide (CO2) laser, which generates radiation having a wavelength in a range of approximately 9.0 to 10.6 μm; and semiconductor diode lasers, which generate radiation having a wavelength in a range of approximately 400 to 1550 nm. 
         [0027]    Depicted in  FIG. 3A  is a side view of an example laser handpiece device  100 . The handpiece  100  includes an input end  112  and an output end  114 . The input end  112  receives several optical fibers  116  through which electromagnetic energy is delivered to the handpiece  100 . Laser beams that are directed to the interaction zone at the surgical target exit the handpiece at the output end  114 . In the device illustrated, the height of the handpiece is larger at the input end than at the output end. This configuration reflects that at the input end, in the example device, several optical fibers enter the handpiece in a honeycomb shaped bundle. In a transition region  120  in the handpiece, the optical fibers transition from a honeycomb shaped bundle to a flattened arrangement wherein at the output end the optical fibers are arranged in a flat parallel row of optical fibers. 
         [0028]    Depicted in  FIG. 3B  is a top view of the example laser handpiece device  100 . This view illustrates the flattening of the fiber optic bundle to a flat parallel row of optical fibers. In this example, the width of the handpiece is larger at the output end than at the input end also highlighting the transition of the optical fibers from a honeycomb shaped bundle to a flat arrangement. 
         [0029]    Other physical configurations of the laser handpiece device can be constructed. Depicted in  FIG. 3C  is a view of an example handpiece having a cylindrical shape. At the input end several optical fibers  116  enter the handpiece in a honeycomb shaped bundle. In a transition region  120  in the handpiece, the optical fibers transition from a honeycomb shaped bundle to a flattened arrangement. At the output end the optical fibers are arranged in a flat parallel row of optical fibers. The diameter of this example device is sufficient to accommodate the honeycomb shaped bundle of optical fibers at the input end and the flat arrangement at the output end. 
         [0030]    Depicted in  FIG. 4A  is a view of the transition region  120 . A bundle of optical fibers  116  having a bundle diameter d enter the transition region. The optical fibers are separated from the bundle in the transition region and fan-out  122  of the optical fibers occurs. The optical fibers exit the transition region arranged in a flat parallel row of optical fibers  124  having a width w that is greater in magnitude than d. 
         [0031]    Depicted in  FIG. 4B  is an example housing  126  for fanning out the optical fibers. The fibers may be fabricated of materials such as low OH quartz, germanium oxide, aluminum fluoride, or sapphire. The housing  126  could be constructed from glass, glass fiber, stainless steel or other suitable material. The housing  126  can receive a fiber optic bundle at an input opening  128  and dispense a flat parallel row of optical fibers at an output opening  130 . The housing  126  has a transition region between the two openings  128 ,  130  to allow the optical fibers to separate from the bundle and fan-out. 
         [0032]    The laser handpiece may be constructed with various numbers of fibers, fiber dimensions and shapes. For example, the handpiece may comprise about  10  fibers for emitting  10  laser beams for cutting a 1 cm bone. As another example, about 50 fibers for emitting 50 beams may be employed for the cutting of a 5 cm bone. 
         [0033]    The light in the fibers are collimated and concentrated to produce a very concentrated light in each optical fiber. Depicted in  FIG. 5A  is an example system for dispersing collimated light  132  from a collimated laser source to the individual optical fibers that enter the handheld device. One or more mirror(s)  134  or a prism direct collimated light from a collimated power source to specific regions  136  at which the inputs to the optical fibers are located. The mirrors disperse power to multiple fibers in a controlled manner so that the power in the individual fibers will be the same. The mirrors can be controlled in a periodic or non-linear manner, but controlled to ensure that the energy from the collimated light is dispersed evenly to the various optical fibers. This allows for an even distribution of the laser energy when it exits the handpiece. In this example system, the scanning beam has a width W 1  at a distance L 2 =˜2-5 cm and scanning width W 2 =˜2-5 cm. By adjusting the scanning width W 1  relative to W 2 , the power density of the light entering the optical fibers can be adjusted. 
         [0034]    Depicted in  FIGS. 5B-5D  are example control signals for controlling the scan rate of mirror  134 .  FIG. 5B  illustrates the use of a triangular shaped control signal.  FIG. 5C  illustrates the use of a higher frequency triangular shaped control signal.  FIG. 5D  illustrates the use of a non-linear control signal. 
         [0035]    As illustrated in  FIG. 6A , electromagnetic energy  140  dispensed from an example handpiece  142  may be collimated and therefore will spread slowly as it propagates toward a cut zone  144  at a surgical target  146 . As illustrated in  FIG. 6B , various lens tips may be applied to the end  148  of handpiece  142  to cause varied spreading of the electromagnetic energy as it is dispensed to different cut zones. Lens tips may also be used to cause clearer cuts. Tapered tip  150  may be used to direct the electromagnetic energy to the side as it leaves the handpiece. The use of rectangular tip  152  may not cause the electromagnetic energy to spread as it leaves the handpiece. Rounded tip  154  may be used to focus the electromagnetic energy at a specific distance from the handpiece. Use of tips with various shapes may be of particular interest in difficult to access areas, like periodontal pockets or root canal system in dentistry; or in the intervertibral disk area in the spine. 
         [0036]    Depicted in  FIG. 7A  is an example handpiece  158  having a fluid inlet  160  and a gas inlet  162 . The handpiece  158  also includes water outlets  164  between and/or around the fibers  166  as also illustrated in  FIG. 7B . By inputting fluid such as water through fluid inlet  160  and pressurize gas such as forced air through the gas inlet  162 , the handpiece  158  can expel fluid particles at a target via outlets  164  in addition to directing electromagnetic energy toward the target. The handpiece therefore can also function as a fluid router for injecting fluid particles into the interaction zone. 
         [0037]    Depicted in  FIGS. 8A-8D  are example arrangements of the optical fibers at the output end of a handpiece.  FIG. 8A  illustrates an arrangement that could yield a standard cut length.  FIG. 8B  illustrates an arrangement that could result in a curved or non-linear cut.  FIG. 8C  illustrates an arrangement that can result in a longer cut length.  FIG. 8D  illustrates an arrangement that can result in a wider cut area.  FIG. 8E  illustrates an arrangement that can result in a circular cut.  FIG. 8F  illustrates an arrangement that can result in an angled cut. These examples illustrate that the optical fibers can be arranged in various shapes and lengths to create the optimal cutting pattern. 
         [0038]    Depicted in  FIGS. 9A-9C  are examples of tooth crown sectioning with vertical ( FIG. 9B ) and horizontal ( FIG. 9C ) cutting tips. 
         [0039]    This written description uses examples to disclose the invention, including the best mode, and also to enable a person skilled in the art to make and use the invention. The patentable scope of the invention may include other examples. 
         [0040]    It should be understood that as used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Further, as used in the description herein and throughout the claims that follow, the meaning of “each” does not require “each and every” unless the context clearly dictates otherwise. Finally, as used in the description herein and throughout the claims that follow, the meanings of “and” and “or” include both the conjunctive and disjunctive and may be used interchangeably unless the context expressly dictates otherwise; the phrase “exclusive of” may be used to indicate situations where only the disjunctive meaning may apply.