Algorithms for Contact Detection and Contact Localization in Continuum Robots

Summary

This technology enhances the capabilities of continuum robots by not only detecting contact during movement but also estimating the position of the contact during the movements executed by the robot. An algorithmic feedback loop can then constrain the movement of the robot to avoid damage to its robot arm, damage to another robot arm or damage to surrounding structure. Applications for this technology include enhanced safe telemanipulation for multi-arm continuum robots in surgery, micro-assembly in confined spaces, and exploration in unknown environments.

Challenges in Robotic Surgery

• Minimally invasive procedures are usually performed using several tools and surgical ports; with several tools operating in such a small space, there are thus potential hazards associated with the tools running into each other, especially in a robotic procedure

• To safely navigate uncertain surgical environments, a robot must be able to detect instances in which it contacts surrounding tissue or other surgical tools

• Previous work on contact detection suffers from the uncertainty about the location of the contact

• Deep reach into the human body is required by natural orifice surgery and other emerging surgical paradigms. These surgical approaches necessitate robots capable of operating along tortuous and long anatomical paths where contact along the robot body is inevitable, but must be monitered to safeguard against trauma to the anatomy.

Other Challenges in Robotics

• Robots operating in unstructered environments where the user operates a robot with many joints to control an end effector require control algorithms allowing the robot to detect and localize contacts so as to enable safe telemanipulation

• Examples of industrial application include continuum robots for assembly of small parts inside electronic guide tubes, and assembly in cluttered environments such as car dashboards

• Other applications include exploration of sewage pipes, robots for archeological exploration and robots for search and rescue missions

Technology Description

For illustration purposes, the following description is written within the context of robotic surgery although the relevance of these algorithms for other application areas listed above becomes self-evident after following the illustrative example within the context of robot surgery. This group of algorithms enables an actively compliant continuum robot to detect an instance of contact and to localize that contact during a surgical procedure. The algorithm compares theoretical and actual positions of the continuum robot to identify a collision, and upon identifying contact, the robot can immediately move to relieve contact and ensure that no damage is done to the robot or surrounding tissue. These contact algorithms also guide the continuum robot in safely bracing against the anatomy to increase precision and stability during a procedure. These capabilities significantly increase the complexity of procedures that can be performed by robotic surgical systems.

Commercial Applications

Robotic systems have shown exciting potential in their ability to perform minimally invasive surgical procedures with more precision than a human surgeon alone. Continuum robots promise to expand this potential by providing dexterous access deep inside the anatomy. This algorithm greatly expands the potential of these continuum robots by allowing them to operate deep inside unstructured environments and significantly reducing the possibility of damaging any tissue or surgical tool. These algorithms can support applications in the area of natural orifice transluminal surgery, trans-anal surgery, and many other minimally invasive procedures.

Unique Features and Competitive Advantages

• This algorithm allows for both detection and localization of contact without perceptible delay that precludes robot telemanipulation

• This algorithm enables the continuum robot to safely brace itself against the anatomy while ensuring that the tissue it contacts isn’t damaged

• Bracing increases the stiffness and accuracy at the tool tip while ensuring that sensitive tissue isn’t damaged

• This technology enables the robot to be safely and rapidly deployed into unstructured environments

Intellectual Property Status

PCT application was filed on 5/10/2013

Inventor Bio and Publications: Vanderbilt University A.R.M.A. Lab http://arma.vuse.vanderbilt.edu/

For more information: Goldman et al. (2011)

Inventors: 
Nabil SimaanAndrea Bajo
Licensing manager: 
Ashok Choudhury

Featured Video

Vanderbilt Patent Activity

View Vanderbilt University Patents

CTTC on Twitter