# US 8,668,710 B2 · Ultrasonic tissue dissector

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- Number: US 8,668,710 B2
- Document ID: US8668710B2
- Status: Granted
- Kind: B2
- Application number: 12/994,029
- Filed: 2009-05-21
- Published: 2011-06-02
- Granted: 2014-03-11
- Earliest claimed: 2008-05-21
- Assignees: Sra Developments Limited
- Applicants: James Anton Slipszenko; Michael James Ede; Stephen Michael Radley Young
- Inventors: James Anton Slipszenko; Michael James Ede; Stephen Michael Radley Young
- Web page: https://patentgrep.com/patent/US8668710B2

## CPC

- A61B 17/320068: {using mechanical vibrations, e.g. ultrasonic (A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745)}
- A61B 17/320092: {with additional movable means for clamping or cutting tissue, e.g. with a pivoting jaw}
- A61B 2017/22011: {Combined types of vibration, e.g. ultrasonic and electrohydraulic}
- A61B 2017/22018: {segmented along its length}
- A61B 2017/22024: {with a part reflecting mechanical vibrations, e.g. for focusing}
- A61B 2017/22027: {Features of transducers}
- A61B 2017/320069: {for ablating tissue}
- A61B 2017/320078: {Tissue manipulating surface}
- A61B 2017/320089: {node location}
- A61B 2017/320094: {additional movable means performing clamping operation}
- A61B 2017/320095: {with sealing or cauterizing means}
- A61B 2017/320098: {with transverse or torsional motion}
- Y10T 29/49005: Acoustic transducer
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An ultrasonic surgical tool has an elongate waveguide operatively connected or connectable to a source of ultrasonic vibrations. An operative element at a distal end of the waveguide has a diameter less than that of the waveguide. A connecting portion of intermediate diameter may connect the operative element and the waveguide. A proximal end of the operative element forms a first step junction, located at a nodal plane of ultrasonic vibrations in the waveguide and operative element, producing a velocity amplitude gain across the step junction. A second zero-gain step junction between the connecting portion and the waveguide is located at an anti-nodal plane. The operative element may include a curved distal cutting and welding element having a pair of elongate welding grooves defining a cutting edge. Alternatively, the operative element may include a welding element having a flat or slightly ridged operative face.

## Claims

### Claim 1

A surgical tool comprising:
an elongate waveguide configured for being operatively connected at a proximal end to an ultrasonic generator means for generating ultrasonic vibrations, wherein the waveguide has a first diameter, and
an operative element provided adjacent a distal end of the waveguide, wherein the operative element comprises an elongate effector element having a second diameter, less than the first diameter, and an elongate intermediate portion extending between the waveguide and the effector element and having a third diameter intermediate between said first and second diameters, and wherein
a first step junction with the effector element is defined at a distal end of the intermediate portion and a second step junction with the waveguide is defined at a proximal end of the intermediate portion,
said first step junction being located substantially in a nodal plane of ultrasonic vibrations generated in the waveguide, and said second step junction being located substantially at an anti-nodal plane of ultrasonic vibrations generated in the waveguide; wherein the intermediate portion has a length substantially corresponding to a quarter of the wavelength of the ultrasonic vibrations therein.

### Claim 2 (depends on 1)

A surgical tool as claimed in claim 1, wherein the surgical tool is adapted to be activated by torsional-mode ultrasonic vibrations.

### Claim 3 (depends on 1)

A surgical tool as claimed in claim 1, wherein a distal end of the effector element is located at an anti-nodal plane of the ultrasonic vibrations.

### Claim 4 (depends on 1)

A surgical tool as claimed in claim 1, wherein the ultrasonic generator means is driven by pulse mode electrical drive means.

### Claim 5 (depends on 1)

A surgical tool as claimed in claim 1, wherein the operative element comprises a non-vibratable jaw member, selectably operable to hold a desired zone of tissue in contact with the ultrasonically-vibratable effector element.