Titan Medical Inc (TMDIF)

[elMoose]

Single port is more expensiv because I believe that it is a more complex robot to design and control. I have read that ISRG's is 2 million previously too.

"Advantages
Many robots are limited by the use of motorized wheels. However, there are many advantages for building a robot that mimics the motion of a snake. Several advantages for movement of a snake robot are listed below:

Move across uneven terrain, since it is not dependent on wheels
Possibly swim if water-proofed
Move across soft ground such as sand, since it can distribute its weight across a wider area
Also, from a systems standpoint, the snake robot can be very modular with many redundant segments. As a result, it is very easy to replace broken segments as well as shorten or lengthen the robot.

Disadvantages
Although there are many advantages for building a snake like robot, there are several disadvantages which are listed below:

Low power and movement efficiency
High cost of actuators (servos or motors)
Difficult to control high number of degrees of freedom"
http://hades.mech.northwestern.edu/index.php/Robot_Snake