Module 4: Biomedical Engineering

Which group of materials could be used in surgical instruments today?

• PMMA, stainless steel, titanium

• UHMWPE, ebony, ivory, PMMA

• titanium, Co-Cr alloy, UHMWPE

• stainless steel, titanium, Co-Cr alloy

Answer explanation

PMMA is a polymer used as a bone cement.

Ebony and ivory are no longer used in surgical instruments due to problems with sterilisation.

HMWPE is a polymer that has been used to form the cup portion of hip prothetics.

A lever with the effort between the fulcrum and the load is a

• first-class lever

• second-class lever

• third-class lever

• first-time lever

Answer explanation

The levers of the human body predominantly act as

• magnifiers of force.

• magnifiers of effort.

• magnifiers of motion.

• A, B and C

Logic gates

• work once only.

• invert all decisions.

• are the building blocks of digital systems.

• produce outputs in a variety of coded formats.

Hot isostatic pressing is performed to

• repair surface defects,

• reduce the size of castings.

• improve dimensional tolerances.

• improve mechanical properties of castings.

Hydroxyaptite is defined as

• bioinert.

• bioactive.

• natural bone.

• chemically inert.

Answer explanation

Bioactive is a material similar to the inorganic component of natural bone and therefore compatible with the normal body process of bone dissolution and growth.

Calculate the mechanical advantage of the system

shown, given efficiency is 100%.

• 0.08

• 8.00

• 12.5

• 0.125