Abstract:
A light, self-contained, hand held, ultrasonic surgical scalpel having a housing, an ultrasonic power source within the housing, to which ultrasonic vibrations are provided to a blade to which result in cutting features by lateral motion as well as by reciprocating motion imparted to the blades with said cutting action being adjustable.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a device for performing surgery particularly an ultrasonic scalpel wherein the scalpel is fully self-contained using batteries as a primary source of power with a switch to permit selection between cutting and cautery modes. When operated the ultrasonic scalpel has the ability for lateral motion as well as reciprocating motion of the scalpel blade causing tissue separation along interstitial margins. 
     2. Description of the Prior Art 
     In the prior art, it is well known that an ultrasonic surgery avoids the trauma, extensive scarring, and limitations of thermal cutting of electrosurgery and laser surgery. In ultrasonic surgery, the ultrasonic scalpel takes advantage of dissection technology as a result of oscillating motion of the blades. Ultrasonic energy is transmitted through a connection or mount between the ultrasonic energy source and a hand-held coupler which mounts the surgical tool, for example, a surgical blade mounted at the tip of the coupler. This connection facilitates transmission of ultrasonic motion from the energy source through the coupler to the surgical blade in order to generate vibrations in the blade in a reciprocating motion. This ultrasonic motion is then coupled with the tissue to which the blade is applied. 
     It was generally thought that the same sharp blades used with hand-held surgical scalpels should also be used with ultrasonic scalpels. It was discovered that in ultrasonic surgical instruments, duller blades achieved exceptional coagulation and cut better than by using sharp conventional scalpel blades. In fact, the duller blade greater transmission of ultrasonic energy is provided to adjoining tissue at the surgical site. This increased transmission was a result of increased blade cutting area in contact with the tissue. Better acoustic coupling as a result of greater transmission of ultrasonic energy enhances cutting capability and capacity for hemostatis. It was found, too, that grinding blades to reduce and modify cross-sectional area enhanced the harmonic “whip” effect. 
     Existing ultrasonic scalpels can be applied to tissue with a vibrating reciprocating motion. While this reciprocating motion accompanied with dull blades has advantages over ultrasonic scalpels fitted with sharp blades, improved cutting with ease and quality can be achieved if there is lateral motion of the blades as well. Existing ultrasonic scalpels do not have the ability to achieve both ultrasonic lateral and reciprocating motion of the blade. 
     Existing ultrasonic scalpels also have the disadvantage of relying on external power supplies which connect to the surgical device by cord. Connection by cord to a power source can hamper portability of the scalpel as well as being cumbersome in some surgical operations. 
     Examples of prior art in this field include U.S. Pat. No. 4,587,958 entitled “Ultrasonic Surgical Device” issued to Noguchi et al. on May 13, 1986; U.S. Pat. No. 4,832,022 entitled “Cryogenic Ultrasonic Scalpel” issued to Tjulkov et al. on May 23, 1989; U.S. Pat. No. 5,026,387 entitled “Method and Apparatus For Ultrasonic Surgical Cutting and Hemostatis” issued to Thomas on Jun. 25, 1991; U.S. Pat. No. 5,167,725 entitled “Titanium Alloy Blade Coupler Coated With Nickel-Chrome For Ultrasonic Scalpel” issued to Clark et al. on Dec. 01, 1992; U.S. Pat. No. 5,254,082 entitled “Ultrasonic Surgical Scalpel” issued to Takase on Oct. 19, 1993; U.S. Pat. No. 5,263,957 entitled “Ultrasonic Scalpel Blade and Methods of Application” issued to Davison on Nov. 23, 1993; U.S. Pat. No. 5,324,299 entitled “Ultrasonic Scalpel Blade and Methods of Application” issued to Davison et al. on Jun. 28, 1994; and U.S. Pat. No. 6,080,175 entitled “Surgical Cutting Instrument and Method of Use” issued to Hogendijk on Jun. 27, 2000. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide an ultrasonic scalpel which imparts lateral harmonic motion to the blade and in addition reciprocating motion. 
     It is therefore a further object of the invention to provide an ultrasonic scalpel which can be used in improved cutting and dissection with ease and quality. 
     It is therefore a still further object of the invention to provide an ultrasonic scalpel which can be used in incising with superior subsequent wound healing and with minimization of scar tissue. 
     It is therefore a still further object of the invention to provide an ultrasonic scalpel which can effectively cauterize an incision with minimization of scar tissue. 
     It is therefore a still further object of the invention to provide an ultrasonic scalpel in a light, self-contained, hand held device thereby improving utility by weight and size advantages. 
     It is therefore a still further object of the invention to provide an ultrasonic scalpel which is disposable. 
     To attain the objects described, there is provided an ultrasonic scalpel ideally suited for minimally invasive surgery comprising a housing with a keyed cylinder and a blade coupler having a blade body and a shank extending from the blade body for coupling with a source of ultrasonic energy and transmitting the energy to the blade body. A transducer transmits ultrasonic energy to the blade causing both reciprocating and harmonic lateral motion of the blade. The ultrasonic energy transmitted from the transducer which causes harmonic lateral motion of the blade is due to an offset of approximately one half to two degrees between the drive of the transducer and the armature within the keyed cylinder. In addition the blade may also be subject to reciprocating motion. 
     The lateral harmonic motion produced is the reason for the ease and quality of a surgical cut and is the preferred embodiment of this invention. Improved cutting by enhanced tissue separation along interstitial margins is demonstrated. In the coagulation mode, the scalpel can operate at lower frequency and higher power providing thermal sealing. The proteinatious nature of tissue breakdown in the region surgerized at cutting frequency causes development of adherent surfaces leading to a coagulation effect. This coagulation effect enhances healing with a minimization of scar tissue. 
     The ultrasonic scalpel of this invention does not require the use of a power cord connected to an external source. A power cord in the close area of surgical operations can be cumbersome and hinder ease of movement of the ultrasonic scalpel. Instead, the power source of the scalpel is batteries in a section of the ultrasonic scalpel housing itself; however, there is capability for an external power source if needed. Also, the weight and size of other required parts of the ultrasonic scalpel such as the electrical actuator and the circuit components with transformer can be reduced. Since the entire ultrasonic scalpel could operate without a separate power supply, the unit is conceivable disposable. 
     These and other objects and characteristics of the present invention will become apparent from the further disclosure to be made in the detailed description given below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred embodiments of the present invention will now be explained in detail with reference to the accompanying drawings, wherein: 
     FIG. 1 is a side view in section of the ultrasonic scalpel of the present invention. 
     FIG. 2 is a top plan view showing the scalpel of FIG.  1 . 
     FIG. 3 is a top plan view of the cylinder/armature arrangement of the present invention illustrating the degree of difference between the armature axis and the drive axis as well as the wall clearance between the keyed cylinder and the housing of the ultrasonic scalpel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings in detail wherein like numerals refer to like elements throughout the several views, FIG. 1 is a side cut-away view of ultrasonic scalpel  10 . 
     Housing  12  of the ultrasonic scalpel  10  of FIG. 1 is shaped to be grasped by the surgeon to allow the surgeon to grip and manipulate during surgery. The shape of housing  12  is an elongated rounded body with varying circumferences. At the far end of the body of housing  12 , removable sections are located on the housing face to allow for the insertion of a power source, batteries  14  and a power cord  16 . From the power end  18 , the circumference of the body decreases to a gripping area  20  which is the majority of the outside surface area of the housing  12 . From the gripping area  20 , the circumference of the body decreases to a circumference slightly larger than the width of blade  22 , which allows improved sight of the action of blade  22 . At the distal end  24  of the body of housing  12 , an aperture  25  is provided for insertion of blade  22  to connect with the keyed cylinder  26  of the ultrasonic scalpel  10 . 
     In FIG. 2, blade  22  can be one of several special purpose blades pre-fitted for the ultrasonic scalpel for different types of surgery or designed for reciprocating and/or lateral motion of the ultrasonic scalpel. Blade  22  has opposite side faces  28  and  30  and may be made of metal, ceramic, a combination of both or other material suitable for the purpose. For example, when an ultrasonic scalpel is made for lateral motion only, specially shaped and ground blades ensure proper mass and balance throughout the length of the blade. 
     In FIG. 1 blade  22  has a side edge  32  and a tip  34  opposite the shank  36 . An aperture  38  is provided in the shank face for receiving the extrusion  27  of keyed cylinder  26 . As shown in FIG. 2, extrusion  27  has a flattened section with a raised surface  40  on one side face sized to fit conformably with the aperture  38  of blade  22 . 
     As shown in FIG. 1, blade  22  moves in relation to the movement of armature  42  in a reciprocating motion as depicted by the direction arrows. Reciprocating motion is vibration in the direction of the axis of the blade  22 . FIG. 2 depicts the motion of blade  22  in relation to the movement of armature  42  in a lateral motion as depicted by the direction arrows. Lateral motion is vibration in a direction perpendicular to the axis of the blade  22 . 
     It should be understood that in certain circumstances lateral motion alone may be sufficient and desirable without reciprocating motion. Without reciprocating motion imparted to scalpel blade  22 , tissue separation occurs only at the nodes of harmonic motion and sugerization occurs as the scalpel blade is manually drawn across the surgical field. The blade  22  and driver  50  assembly may be fabricated in a manner to provide only lateral “whip” motion along the length of blade  22 . 
     In FIG. 3, the elongated flattened section  44  of extrusion  27  is the blade attachment section. The tubular section  46  of the armature  42  is the keyed cylinder  26  attachment area. Inside the body of the housing  12  near the aperture  25  is the keyed cylinder  26 . The interior of the keyed cylinder  26  confines the armature  42  and transmits the ultrasonic vibration of the armature  42  to blade  22 . 
     The armature  42  has a solid tubular section  46  which moves within and impacts the movement of the keyed cylinder  26 . The other end  48  of the body of armature  42  slidably inserts into the driver  50  of transducer  52 . Armature  42  can slidably insert into the driver  50  at an offset as exaggerated in the illustration of FIG.  3 . The driver  50  of the transducer  52  is rounded and has a recessed area  54  for engaging the armature  42 . 
     The ultrasonic scalpel  10  is energized by a tool tip ultrasonic transducer  52 . The transducer  52  vibrates and transmits this vibration through the driver  50  and armature  42  at a controlled frequency to the blade  22 , causing reciprocating motion of the blade  22 . The blade excursion is a function of electrical power input to the transducer  52 . 
     Ultrasonic vibration for lateral harmonic motion of blade  22  is caused by the one half to two degree offset of the driver  50  axis and the armature  42  axis. The keyed cylinder  26  has a one-thousandth of an inch (0.001″) clearance from the housing  12  to allow whip movement caused by the lateral harmonic motion. The ultrasonic scalpel  10  can be limited to transmitting ultrasonic vibration for solely lateral harmonic motion. 
     In FIG. 3, a piezo beam driver electrically connected to circuit board  56  could provide lateral “whip” motion when connected directly to blade  22 . An anchor section of driver  50  is the blade attachment section. The driver is preferably a Thunder Beam of Thunder Technology described with transducer  52 ; however suitable alternatives may be used. 
     The transducer  52  of FIG. 1 has a piezoelectric driver which preferably contains Thunder Technology, which is a high deformation Piezo electrical actuator, (described and illustrated in U.S. Pat. No. 5,632,841 issued May 27, 1997 to NASA; U.S. Pat. No. 5,639,850 issued Jun. 27, 1997 to NASA; and U.S. Pat. No. 6,030,480 issued Feb. 29, 2000 to Face International, the disclosures of which are incorporated herein by reference); however, those skilled in the art will recognize various equivalent substitutions. Operating frequencies of between 40 kHz and 65 kHz have been found to work particularly well. High voltage to the transducer  52  is provided by way of the circuit board  56 . The circuit board  56  is a wafer-type rectangular shape. At one end of its face, the circuit board  56  connects electrically to the transducer  52 . 
     To provide high voltage to the circuit board  56 , a transformer  58  will be connected electrically on the circuit board face of the end opposite the attached transducer  52 . The transformer  58  will preferably be a Transoner type (described and illustrated in U.S. Pat. No. 5,834,882 issued to Face International, the disclosure of which is incorporated herein by reference). Transoner is a multi-layer piezo electric transformer. Of extremely small size, this device can step up 6 volts to as high as 900 volts; however, those skilled in the art will recognize various equivalent substitutions. 
     To supply power to the transformer  58 , the housing  12  provides interior space for two batteries  14  and an aperture  18  for a connection to an external power source  16 . These power sources are connected electrically to the transformer  58 . The batteries  14  for the power source can have a lithium core which would enable the ultrasonic scalpel  10  to be operated for 15 minutes. This is adequate because in many surgical procedures, the ultrasonic scalpel  10  is not in continuous use. 
     The housing  12  has an aperture opening  60  on the exterior gripping section  20  of the body for function switch  62 . Function switch  62  comfortably fits in the opening  60  of the exterior of the housing  12  and is attached to the circuit board  56 . The function switch  62  is in the form of a sliding button. The function switch  62  allows the operator to control the application of ultrasonic vibrations to the blade  22  for cutting and coagulation modes. 
     Without the need for but with the ability to use an external power supply, the ultrasonic scalpel  10  can be disposable. Also, the ultrasonic scalpel  10  one can be available in different power and frequency models, for varying surgical application. 
     While the invention has been described in connection with what is considered to be the most practical and preferred embodiment, it should be understood that this invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.