Patent Application
20130123821
1. Field of the Invention
This invention relates, generally, to apparatus and methods used in surgical procedures, generally (although not necessarily restricted to) surgery of different types on human patients. More specifically, the invention relates to a type of single-use scalpel or surgical instrument, namely a neuro-dissector, having design and material attributes which prevent multiple use.
2. Background
Surgical instruments of many sorts are known in the art. In particular, various types of surgical instruments are used in neurological and similar procedures. Such surgical procedures require dissection of certain tissue, while at the same time requiring protection against dissection of surrounding tissue. It is important that the surgeon be able to readily visualize the tissues being dissected, in order to properly guide the surgical instrument. Types of surgical procedures which require neurological dissection include, but are not limited to:
Yet another issue arises in connection with these types of surgical procedures, and the instruments used to carry them out. Sterilization and sharpening of multi-use instruments used in neurological procedures becomes problematic. With regard to sterilization, as is well known, multi-use surgical instruments must be sterilized to a high sterility assurance level (known as SAL) between uses. While various methods of sterilization exist, probably the most common is steam sterilization at a combination of high temperature (typically 250 F to 273 F) and pressure, applied in an autoclave, with the surgical instrument present for a sufficient length of time (typically in the range of 3 to 15 minutes, depending upon temperature). Despite best practices, there is the ever-present risk of inadequate sterilization procedures being carried out on multi-use devices, as opposed to single-use devices that can be manufactured, packaged, and shipped in a sterile environment and packaging, only opened by the surgical staff at the time of use. With regard to sharpening, it can be readily appreciated that surgical instruments must be of the utmost sharpness. The very small cutting surfaces on many of the dissectors used in neurological procedures are frequently difficult to effectively resharpen, hence reuse presents issues associated with insufficiently sharpened instruments.
Known neuro-dissector instruments present various limitations due to their structure and intended use as multi-use instruments. The present invention comprises structural attributes which permit efficient and safe dissection of neurological tissues, and is a single use instrument, which must be discarded after one use.
Accordingly, the neuro-dissector has an elongated handle which affords a comfortable and secure grip for the surgeon. The handle is preferably made of a material which will degrade when subjected to heat sterilization techniques. While various materials may be possible, one suitable material is a low density polyethylene plastic which degrades with heat. Thus, subjecting the handle to sterilization by heat will result in its destruction, and renders the dissector unusable. Preferably, the overall contour of the handle includes a rounded, larger diameter section nearest one end, with a smaller, uniform diameter section proximal the opposite end. A non-slip surface may be provided on the handle, for example a number of ridges, ribs or fins forming the outer diameter of the handle.
The neuro-dissector handle holds an extended rod or similar shaped member, with a section proximate the distal end (the end farthest from the handle) turned down to form the cutting surface and cutting edge. Preferably, the rod is attached to the larger diameter end of the handle. The cutting surface and cutting edge is generally aligned at a large angle, for example a seventy degree angle, to the longitudinal axis of the rod. This alignment means that the cutting action for the neuro-dissector is generally a pulling action on the instrument. The rod terminates in a blunt ball tip, which is non-cutting and provides protection to the target neural tissue. The alignment of the handle, rod, and cutting edge are such that the surgeon can maintain full visualization during surgery.
The cutting edge of the dissector is also designed to ensure single use. The rod, including the cutting edge, is preferably of stainless steel. The actual cutting edge is coated with a substance which is extremely hard and destructive to sharpening devices, thereby ensuring that the cutting edge will not be re-sharpened and enforcing the single-use aspect of the device. One suitable cutting surface and cutting edge coating material is titanium nitride (TiN).
While the apparatus may take various forms, all falling within the scope of the present invention, with reference to the figures some of the presently preferred embodiments will now be described.
The surgical instrument of the present invention, namely a single use, multi-purpose neuro-dissector 10, referred to at times as dissector 10, comprises an elongated handle 20 with first and second ends 21 and 22 and an extended rod 30 fixed to and extending outwardly from handle 20, with a distal end section 40, as readily seen in
With regard to rod 30, distal end section 40 is bent from the longitudinal axis of rod 30 at a suitable angle to form a cutting surface 50, as seen in
Rod 30 may be joined to handle 20 by threading, adhesively joining, or other methods well known in the art. If desired, rod 30 may be fixed to handle 20 such that the longitudinal axis of rod 30 forms an angle with the longitudinal axis of handle 20, to permit complete visualization of the cutting surface and the tissues being cut, by the surgeon. While various angles may be suitable, from about 0 to 20 degrees, the angle is preferably about 10-12 degrees, depending upon the line of sight of the individual user. Rod 30 is preferably made of stainless steel or other suitable material, with a length beyond handle 20 of approximately 4 inches and a base diameter of 1/8 inch, tapering toward the distal end section. It is understood that dimensions and materials may be changed to suit the user. One suitable material for rod 30 and cutting surface 50 is stainless steel, grade 17-4 (as specified in ASTM A564/A564M-01).
The materials for handle 20 and cutting surface 50 are important for the single-use aspect of dissector 10. Handle 20, generally, is of a material which will degrade with heat and pressure to such an extent that dissector 10 would be unusable, if heat/pressure sterilization were attempted. While various materials may be suitable, one presently preferred material comprises a low density polyethylene plastic, which will substantially degrade with heat and pressure. It is understood that other materials may be possible.
In addition to the attributes of handle 20, cutting surface 50 and edge 52 are coated with a substance which is very hard and destructive to sharpening devices, thereby ensuring that the cutting surface 50 and edge 52 will not be re-sharpened, and enforcing the single-use aspect of the device. One suitable cutting surface coating material is titanium nitride (sometimes referred to in the art as TiN). It is known in the art that TiN is an extremely hard ceramic material, often used to harden and protect cutting surfaces. It is not readily re-sharpenable, in fact is sufficiently hard that it would be destructive to sharpening devices. It is understood that other materials may be suitable for coating of cutting surface 50 and edge 52, as long as they possess properties similar to those of TiN.
While the preceding description contains many specificities, it is to be understood that same are presented only to describe some of the presently preferred embodiments of the invention, and not by way of limitation. Changes can be made to various aspects of the invention, without departing from the scope thereof. For example:
Therefore, the scope of the invention is to be determined not by the illustrative examples set forth above, but by the appended claims and their legal equivalents.
