Pill-sized endoscopic robots

Loading Physical Intelligence Department

Objectives:

To develop a soft capsule robot which is able to diagnose and perform therapeutic operations (e.g., biopsy, elastography, targeted drug delivery, etc.). A magnetically actuated capsule robot is remotely controlled by an external magnetic field, which is precisely controlled by an electromagnetic setup, is able to perform basic rolling locomotion. By taking advantage of the soft material of the capsule robot and magnetic interaction, it is possible to implement feasible medical functions based on shape deformation of the capsule. Finally, it is our goal to develop a capsule robot which makes endoscopic procedure much more comfortable for patients and easy to diagnose and operate for doctors.

Project Members:

Mehmet Turan

Donghoon Son

Past Members:

Paul Glass

Sehyuk Yim

Selected Research Results and Papers

Design and rolling locomotion of a magnetically actuated soft capsule endoscope

This paper proposes a magnetically actuated soft capsuled endoscope (MASCE) as a tetherless miniature mobile robot platform for diagnostic and therapeutic medical applications inside the stomach. Two embedded internal permanent magnets and a large external magnet are used to actuate the robot remotely. The proposed MASCE has three novel features. First, its outside body is made of soft elastomer-based compliant structures. Such compliant structures can deform passively during the robot–tissue contact interactions, which makes the device safer and less invasive. Next, it can be actively deformed in the axial direction by using external magnetic actuation, which provides an extra degree of freedom that enables various advanced functions such as axial position control, drug releasing, drug injection, or biopsy. Finally, it navigates in three dimensions by rolling on the stomach surface as a new surface locomotion method inside the stomach. Here, the external attractive magnetic force is used to anchor the robot on a desired location, and the external magnetic torque is used to roll it to another location, which provides a stable, continuous, and controllable motion. The paper presents design and fabrication methods for the compliant structures of the robot with its axial deformation and position control capability. Rolling-based surface locomotion of the robot using external magnetic torques is modeled, and its feasibility is tested and verified on a synthetic stomach surface by using a magnetically actuated capsule endoscope prototype.

Proposed magnetically actuated soft capsule endoscope (MASCE). (a) MASCE with a US quarter (b) Fully compressed capsule while it is anchored on the synthetic stomach surface. (c) Its shape-deformation demonstration when compressed.

Brief highlighted research result:

S. Yim and M. Sitti, “Design and rolling locomotion of a magnetically actuated soft capsule endoscope,” IEEE Trans. Robotics, vol. 28, no. 1, pp. 183–194, 2012.

A new compliant capsule endoscope, i.e., MASCE, with one extra degree of freedom axial compression motion for tetherless medical procedures in the stomach is proposed. Because this axial motion can be controlled by the external magnetic field, no extra actuator is needed. The proposed compliant capsule endoscope has a potential capability to monitor the whole area of the stomach in 3-D. In addition, it is shown that the axial compression of the capsule can be used to perform therapeutic functions, and the liquid-drug releasing function of MASCE is demonstrated as an example where a critical compressive force of 1.5N triggers such a release through punched holes on the capsule. Next, a magnetic-actuation-based rolling locomotion principle of the capsule robot is proposed where both the position and the orientation of the capsule can be controlled by the usage of an EPM. Position tracking performance of MASCE is shown to be a function of the ratio between translational velocity and rotational velocity of EPM, and the optimal ratio is shown to be in the range of 1–1.5 in both simulations and experiments.

Biopsy using a magnetic capsule endoscope carrying, releasing and retrieving untethered micro-grippers

This paper proposes a new wireless biopsy method where a magnetically actuated untethered soft capsule endoscope (MASCE) carries and releases a large number of thermo-sensitive, untethered microgrippers (micro-grippers) at a desired location inside the stomach and retrieves them after they self-fold and grab tissue samples. We describe the working principles and analytical models for the microgripper release and retrieval mechanisms, and evaluate the proposed biopsy method in ex vivo experiments. This hierarchical approach combining the advanced navigation skills of centimeter scaled untethered magnetic capsule endoscopes with highly parallel, autonomous, sub-millimeter scale tissue sampling microgrippers offers a multi-functional strategy for gastrointestinal capsule biopsy.

S. Yim, E. Gultepe, D. Gracias, and M. Sitti, “Biopsy using a magnetic capsule endoscope carrying, releasing and retrieving untethered micro-grippers,” IEEE Trans. Biomed. Eng., vol. 61, no. 2, pp. 513–521, 2014.

Brief highlighted research result:

Selected Video

Magnetic Capsule Endoscope

Magnetic Capsule Endoscope: carrying, releasing and retrieving untethered micro-grippers

A new compliant capsule endoscope, i.e., MASCE, with one extra degree of freedom axial compression motion for tetherless medical procedures in the stomach is proposed. Because this axial motion can be controlled by the external magnetic field, no extra actuator is needed. The proposed compliant capsule endoscope has a potential capability to monitor the whole area of the stomach in 3-D. In addition, it is shown that the axial compression of the capsule can be used to perform therapeutic functions, and the liquid-drug releasing function of MASCE is demonstrated as an example where a critical compressive force of 1.5N triggers such a release through punched holes on the capsule. Next, a magnetic-actuation-based rolling locomotion principle of the capsule robot is proposed where both the position and the orientation of the capsule can be controlled by the usage of an EPM. Position tracking performance of MASCE is shown to be a function of the ratio between translational velocity and rotational velocity of EPM, and the optimal ratio is shown to be in the range of 1–1.5 in both simulations and experiments.

List of Publications

2014

 

Biopsy using a Magnetic Capsule Endoscope Carrying, Releasing and Retrieving Untethered Micro-Grippers

S Yim, E Gultepe, DH Gracias, M Sitti

IEEE Trans. on Biomedical Engineering 61 (2), 513-521

 

 

2013

 

3-D Localization Method for a Magnetically Actuated Soft Capsule Endoscope and Its Applications

S Yim, M Sitti

IEEE Trans. on Robotics 29 (5), 1139-1151

 

Magnetically Actuated Soft Capsule With the Multimodal Drug Release Function

S Yim, K Goyal, M Sitti

IEEE/ASME Trans. on Mechatronics 18 (4), 1413-1418

 

A 5-D Localization Method for a Magnetically Manipulated Untethered Robot using a 2-D Array of Hall-effect Sensors

D. Son and M. Sitti

submitted to IEEE Trans. Mechatronics.

 

2012

 

Shape-Programmable Soft Capsule Robots for Semi-Implantable Drug Delivery

S Yim, M Sitti

Mechatronics, IEEE/ASME Transactions on

 

 

Design and rolling locomotion of a magnetically actuated soft capsule endoscope

S Yim, M Sitti

Robotics, IEEE Transactions on 28 (1), 183-194

 

 

2011

 

Biaxial mechanical modeling of the small intestine

C Bellini, P Glass, M Sitti, ES Di Martino

Journal of the mechanical behavior of biomedical materials 4 (8), 1727-1740

 

 

2009

 

A Swallowable Tethered Capsule Endoscope for Diagnosing Barrett's Esophagus

P Glass, M Sitti, A Pennathur, R Appasamy

Gastrointestinal Endoscopy 69 (5), AB106

 

2008

 

A legged anchoring mechanism for capsule endoscopes using micropatterned adhesives

P Glass, E Cheung, M Sitti

Biomedical Engineering, IEEE Transactions on 55 (12), 2759-2767

 

 

2006

 

Stopping and Locomotion Mechanism for an Endoscopic Microcapsule Robot

M. E. Karagozler, E. Cheung, and M. Sitti

Proc. of the IEEE/EMBS Biomedical Robotics and Biomechatronics Conference, pp. 105-111, Pisa, Italy, Feb. 2006.

 

2005

 

A new endoscopic microcapsule robot using beetle inspired microfibrillar adhesives

E Cheung, ME Karagozler, S Park, B Kim, M Sitti

Advanced Intelligent Mechatronics. Proceedings, 2005 IEEE/ASME International ...

 

 

Funding Agency

National Institute of Mental Health

(NIH)

National Robotics Initiative

(NRI)