A cast saw on human skin

Summary by Krater

This video explains the physics of how a medical cast saw cuts through a plaster or fiberglass cast without cutting human skin. It demonstrates the oscillating blade mechanism using balloons and skin, and compares plaster and fiberglass casting materials.

From the video

Answers: How does a cast saw cut a cast without cutting skin?

• cast saw physics
• oscillating blade mechanism
• plaster vs fiberglass casts
• human skin elasticity
• shear modulus of skin

What it concludes

• A cast saw uses an oscillating blade rather than a spinning blade to cut rigid materials.
• Human skin acts like an under-inflated balloon, stretching and moving with the oscillating teeth instead of being punctured.
• The total cost of ownership of a Henson AL13 safety razor is lower than a cartridge razor after a few months.
• The Henson AL13 blade protrudes 30 microns at an angle of 12 to 14 radians for a smooth shave.