©Melanie Gonick/MIT

Medical Capsule Robots (MCRs) are the new sensation. Today, we explore various types of MCRs which are a MEMS device, embedded microelectromechanical systems, that can operate autonomously within the human body and have the ability to diagnose, prevent, monitor, and cure diseases.

MCRs are used to reach remote regions of the human Gastrointestinal (GI) tract. Usually, MCRs enter the human body through natural orifices (openings in the body) and are able to perform multiple tasks, such as endoscopy and gastrointestinal surgery, by interacting with the surrounding environment with sensors, actuators, and wireless communication.

The design process and development of MCRs are challenging. There are multiple constraints and limitations such as size (1cm in size for non-invasive access), power (limited battery consumption), and fail-safe operation.

3 cutting edge MCRs on the horizon now:

1. Ingestible origami robot

Swallow, wiggle and remove! Developed by researchers at MIT, University of Sheffield, and Tokyo Institute of Technology, this smart ingestible robot removes batteries and patch wounds in the human stomach. It fits inside a pill for swallowing and can navigate using external magnetic fields.

Swallowed batteries, if not removed, can cause significant damage to the stomach lining. This origami robot can help prevent this problem.

©Tech Insider

©Shuhei Miyashita et al./ICRA Proceedings

2. Drug Delivery Capsule (DDC)

Why DDC? First, large drugs are hard to absorb. Second, some drugs get broken down in the stomach even before they are absorbed. A recently developed DDS, by researchers from Vanderbilt University and Polytechnic University of Milan, uses a coil-magnet-piston mechanism and can deliver drugs directly into the lining of the GI tract. This 16mm in diameter and 25mm in length smart capsule can contain drugs up to 201.06mm³ and weighs 12g. It is a little on the heavy side, but it allows controlled deployment of drug doses over a period of time. Real-time localization and active position control are added features to this smart drug release MEMS device.

(a) Final DDC prototype (16mm in diameter and 25mm in length). (b) The drug being released and (c) drug completely deployed. ©Beccani et al., 2016/Elsevier

3. Wireless capsule endoscopes (WCE)

Endoscopes and colonoscopies are used to diagnose and treat pathologies in the GI tract. These pill-sized MEMS devices take pictures of the intestinal wall that will be used for diagnosis.  They travel via peristalsis in the digestive tract and are used in the stomach, small intestine, and colon.

Researchers from Imperial College London presented a concept of the first WCE with increased functionality to allow targeted drug delivery for therapeutic purposes. To even further increase the functionality, the researchers proposed a biologically-inspired holding mechanism which is based on insects such as beetles (coleopterans) and ladybirds (coccinellidae). For instance, a ladybird has the ability to fold away its wings behind a second pair of wings, which are used as a casing to protect them. A novel approach is to enable the endoscope to resist intestinal peristalsis (natural wavelike movement) using the concept of a pair of folded wings.

©Woods & Constandinou/PubMed
Concept of an integrated holding mechanism delivering 1 mL of medication to a target site.

©Woods & Constandinou/PubMed

Concept of delivering 1 ml of targeted medication. Needle shown fully extended and the medication partially deployed.