Contains the full lesson along with a supporting toolkit, including teachers’ notes.
Most surgery involves a certain amount of cutting of body tissues such as skin, muscle and bone. The more common surgical cutting instruments are scalpels, drills, burs, saws, scissors and rongeurs. Because of the ‘life or death’ nature of surgery, the reliability of surgical tools is very important. In this lesson we explore various aspects of the manufacture of these instruments including choice of materials, manufacturing processes, ease of use, resistance to corrosion and cleanability (‘Is it easily sterilised?’).
The effectiveness of surgical cutting instruments may be enhanced by ultrasonic and/ or electrical components enabling the surgeon to perform accurate and rapid dissection.
Choice of Materials
Surgical steel is the most commonly used material in the manufacture of surgical cutting tools. This is a type of stainless steel that is particularly resistant to scratches and to corrosion.
Steel is an alloy of iron and other elements, most commonly carbon (0.2% and 2.1%). The relatively small amount of carbon makes the steel about a hundred times stronger and harder than pure iron. However, ordinary steel is subject to corrosion (rust) and so would be unsuitable for medical use.
Stainless steel contains substantial amounts of chromium (10.5% or more). Steel used for domestic cutlery typically contains nickel (10%) along with chromium (18%). Unlike nickel plated steel, it does not rust if scratched.
Science and Technology in Action (STA) is proudly supported and partnered by some of Ireland’s leading organisations and is produced in close cooperation with the support services of the Department of Education and Skills and the Irish Science Teachers Association (ISTA).
