In order to facilitate the healing process and achieve the goals of compression anastomosis, the rate of compression must be controlled. This approach may be better executed with the use of memory shape alloys such as Nitinol.

Nitinol is a metal alloy that contains a nearly equal mixture of Nickel and Titanium. Nitinol has unique features which makes it most appropriate for use in biomedical applications in general and in BioDynamix™ Anastomosis technology in particular. The three most prominent properties that describe the behavior of the material are:

• Superelasticity - Nitinol can recover its strain on the order of 8% whereas the best regular spring alloy recovers only 0.4% strain. This high degree of elasticity is also called Superelasticity. 
• Shape Memory - The ability of the material to "memorize" its pre-deformed shape is called Shape Memory. Nitinol is termed a thermal shape memory alloy because it expands and flexes when cooled, but resumes its shape and size when it returns to its normal temperature. 
• Constancy of Stresses - Constant Stress between 1%-6% of Strain is called Constancy of Stresses.

 

Stress (Force) vs. Strain (Extension) for Nitinol and for stainless steel

Because of its powerful and unique qualities, Nitinol has been used in many biomedical applications where constancy of shape and stress are essential, including permanent implants, stents, blood filters, bone staples and needles.

Devices made from nitinol apply a constant stress over a wide range of shapes and strains. Nitinol is biocompatible. Nitinol is more stable and less subject to corrosion than other materials such as stainless steel.

Nitinol is biomechanically compatible.

Its mechanical properties are similar to those observed in various body tissues. Nitinol is more flexible than steel

Use of Nitinol unique properties in the ColonRing™ (CAR™ 27 ring)