Surgery – Instruments – Cutting – puncturing or piercing
Reexamination Certificate
1999-06-30
2001-07-03
Recla, Henry J. (Department: 3731)
Surgery
Instruments
Cutting, puncturing or piercing
C604S022000, C606S171000
Reexamination Certificate
active
06254623
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates, in general, to an improved blade for use in an ultrasonic surgical instrument such as an ultrasonic clamp coagulator and, more particularly, to a blade having improved geometry wherein the cross sectional area of the blade increases from the proximal end of the blade toward the distal end of the blade.
BACKGROUND OF THE INVENTION
Ultrasonic surgical instruments are finding increasingly widespread applications in surgical procedures by virtue of the unique performance characteristics of such instruments. Depending upon the specific instrument configurations and operational parameters, ultrasonic surgical instruments can provide substantially simultaneous cutting of tissue and hemostasis by coagulation, potentially minimizing patient trauma. The cutting action is typically effected by an ultrasonic blade at the distal end of the instrument, with the blade transmitting ultrasonic energy to tissue brought into contact therewith. Ultrasonic instruments of this nature can be configured for open surgical use, or laparoscopic or endoscopic surgical procedures.
In one particular type of ultrasonic instrument, which may be described generally as a clamp coagulator, tissue is forced against an ultrasonic blade by a clamp arm which opposes at least a portion of the ultrasonic blade. In such instruments, the tissue which is positioned between the clamp arm and the blade is compressed against the blade as the clamp arm is closed. Thus the region of the ultrasonic blade opposing the closed clamp arm may be referred to as the compression zone. It is desirable in such an instrument to keep the speed of cutting and coagulation fast to reduce the heat generated in surrounding tissue. The speed at which tissue is cut and coagulated is a function of a number of parameters, including amplitude and frequency of the vibration of the blade and the pressure forcing the tissue against the blade. Instruments such as the clamp coagulator disclosed in U.S. Pat. No. 5,322,055 have blades that have a uniform cross-section in the compression zone. As a result of their uniform compression zone cross-section, the ultrasonic blades illustrated in U.S. Pat. No. 5,322,055 have vibration amplitudes that are greater at their distal ends than at their proximal ends. The result is that cutting and coagulation may take place faster at the distal end of the compression zone than at the proximal end, resulting either in a larger than desired area of coagulation at the distal end of the compression zone or a cut that is shorter and limited to an area near the distal end of the compression zone. Alternatively, tissue positioned at the distal end of the compression zone may be coagulated and cut before tissue at the proximal end is fully coagulated. While none of these limitations is detrimental to the patient, they may result in the surgeon taking smaller bites of the tissue to ensure full coagulation before cutting, thus slowing the surgeon down.
Previous ultrasonic instruments have included ultrasonic blades with variable cross-sectional areas, however, such instruments either do not vary the cross-sectional area of the blade in the compression region of a clamp coagulator. See, for example, U.S. Pat. No. 2,704,333 to Calosi et al. which illustrates an ultrasonic blade which decreases in cross-sectional area from the point of attachment to the distal end. The object of the Calosi invention is to increase vibrational amplitude of the distal end of the ultrasonic blade to effect work upon a piece at the distal end. Calosi teaches placing a higher concentration of mass at the distal end to increase the overall amplitude of the transmitting medium. U.S. Pat. No. 2,990,616, by Balamuth et al. illustrates an ultrasonic cutting tool that has differing geometries to drive vibrations of the tip to effect different characteristics on a cavity being cut into a workpiece. Two U.S. patents by Makool, U.S. Pat. No. 5,354,265 and U.S. Pat. No. 5,505,693, illustrate ultrasonic blades which decrease in cross-sectional area in a region proximal to the useful working area. Davidson et al., U.S., Pat. No. 5,322,055 illustrates ultrasonic blades with varying cross-sectional areas distal to the end of the clamp arm. The particular geometry is added to the tip of the blade so that it is available for useful tasks outside of the compression zone.
It would, therefore, be advantageous to design an ultrasonic clamp coagulator including an ultrasonic blade which has been specifically configured to increase the vibration amplitude in an area adjacent the proximal end of the clamp arm. It would, further, be advantageous to design an ultrasonic clamp coagulator instrument including an ultrasonic blade wherein the vibrational amplitude is greater at the proximal end of the compression zone than the vibrational amplitude in a conventional clamp coagulator. It would further be advantageous to design a clamp coagulator wherein the uniformity of cutting and coagulation within the compression zone is improved over the uniformity obtainable using conventional clamp coagulators.
SUMMARY OF THE INVENTION
An ultrasonic clamp coagulator assembly embodying the principles of the present invention is configured to permit selective cutting, coagulation, and clamping of tissue during surgical procedures. In an ultrasonic blade according to the present invention, the blade is constructed such that the cross-sectional area of the blade is smaller at the proximal end of the compression zone than at the distal end. This performance enhancing feature creates a more consistent cutting and coagulation of the tissue along the length of the blade reducing the time the blade is in operation and reducing overall heat generation.
In particular, in one embodiment of the present invention, an ultrasonic surgical apparatus includes a housing, an ultrasonic drive unit carried by the housing and adapted to generate ultrasonic vibration, an ultrasonic surgical blade having a central axis, a clamp arm, a clamp pad affixed to the clamp arm, a contact region on the outer surface of the ultrasonic surgical blade. In this embodiment, the ultrasonic surgical blade is operatively connected to the ultrasonic transducer, the clamp arm and pad are movable to a closed position opposite the ultrasonic surgical blade substantially parallel to an outer surface of the ultrasonic surgical blade, the blade has a contact region opposite the clamp pad, wherein the blade has a first cross-sectional area within the contact region and adjacent to the proximal end of the contact region and a second cross-sectional area within the contact region and adjacent to the distal end of the contact region, the second cross-sectional area being larger than the first cross sectional area.
Further embodiments of the present invention include ultrasonic surgical clamp coagulator instruments having the following features. A contact region wherein the proximal end of the contact region is aligned with the proximal end of the clamp pad and the distal end of the contact region is aligned with the distal end of the clamp pad. An ultrasonic blade wherein the second cross sectional area is substantially circular in shape. An ultrasonic blade wherein the first cross-sectional area of the ultrasonic blade is substantially circular in shape. A first flat region on a first side of the blade and a second flat region symmetrically positioned on a second side of the blade. A contact surface positioned between the first and second flat regions, the contact surface being narrower at the proximal end of the contact region than at the distal end of the contact region.
REFERENCES:
patent: 2704333 (1955-03-01), Calosi et al.
patent: 2990616 (1961-04-01), Balamuth et al.
patent: 3636943 (1972-01-01), Balamuth
patent: 3862630 (1975-01-01), Balamuth
patent: 5286256 (1994-02-01), Mackool
patent: 5322055 (1994-06-01), Davison et al.
patent: 5354265 (1994-10-01), Mackool
patent: 5449370 (1995-09-01), Vaitekunas
patent: 5505693 (1996-04-01), Mackool
patent: 5873873 (1999-02-01), Smith et al
Bowes William A.
Haibel, Jr. Chester G.
Witt David A.
Ethicon Endo-Surgery Inc.
Ngo Lien
Recla Henry J.
Shay Bernard
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