Source: CUHK Media

Microrobot study represents major advance for ear tubes and other implants

31 October 2022

A novel treatment procedure to eradicate biofilm offers promising sign for clinical application.

Otitis media is an inflammation or infection located in the middle ear. It is a health problem commonly seen in children, usually caused by upper respiratory infections or bacterial infections. About 7% of children under the age of six have had otitis media with effusion, or fluid build-up. The fluid may resolve on its own within a few weeks but if the condition prevails, surgical treatment becomes necessary. The procedure involves the insertion of an ear tube in the tympanic membrane to drain the middle ear fluid, alleviating the effusion and pressure in the middle ear. However, bacterial biofilm may form in the ear tube over time and contribute to blockages and recurring infections. Eradication of the biofilm is difficult in the tortuous and obstructed auditory canals

The Chinese University of Hong Kong (CUHK)’s cross disciplinary research team developed a microrobot that would remove the biofilm from the ear tube. The treatment system consists of helical microrobot, endoscope, magnetic actuation unit with robotic arm, and catheter. Surgeons first use an endoscope to deliver the spiral-shaped microrobot with a catheter into the ear tube. Then they can remotely actuate the microrobot by the programmed magnetic field in the ear tube to perform biofilm eradication.

“Recurrent infections of ear refractory to antibiotic treatment and occlusion of the ear tube are the complications related to biofilms after operation,” explains Dr Chang Wai-tsz, Assistant Professor in the Department of Otorhinolaryngology, Head and Neck Surgery at CU Medicine. “Antibiotics are usually used to prevent biofilm occlusion after surgery, but they cannot prevent infection in the long term, and may lead to antimicrobial resistance. Some patients who suffer from ear tube occlusion require frequent tube replacement, which increases their physical and financial burden.”

The novel treatment procedure has been validated in a human cadaver ex vivo, which is a promising sign for clinical application. This invention may offer better future alternatives to current surgical treatments, easing the physical and psychological pressure from repetitive ear tube replacement.

“Although biofilm has been known for quite some time, the clearance of biofilm has been an unsolved problem for decades,” Professor Joseph Sung, Dean of Lee Kong Chian School of Medicine and CUHK’s Emeritus Professor, said. “So far, no medication has proven to be useful in clearing the microbes once they are established on the surface as a layer. This study represents a major breakthrough using both mechanical and chemical methods in the same modalities. Its application is not limited to ear tubes for otitis media: potentially it can be used in other medical devices or implants placed in the human body where biofilm infections can occur.”

Study results have been published in the international journal Science Advances.