Recently, Prof. Mohamad Sawan, chair professor of microsystems and bioengineering at Westlake University, was elected as a fellow of the Royal Society of Canada (RSC). Founded in 1882, the RSC is Canada's highest national academic institution.

Prof. Sawan is a fellow of the Canadian Academy of Engineering, Engineering Institute of Canada, and Institute of Electrical and Electronic Engineers. As an internationally renowned scientist in the field of smart medical devices, he has made significant contributions to implantable and wearable devices based on microelectronics and microsystem technologies.

Since joining Westlake University as full-time faculty in Fall 2018, Dr. Sawan has focused his team's research on the most complex and delicate human organ - the brain. He founded and now leading the Centre of Excellence inBiomedical Research of Advanced Integrated-on-chips Neurotechnologies (CenBrain Neurotech Center of Excellence), which focuses on the diagnosis, prediction, and treatment of neurodegenerative disorders related to the brain, and other medical diseases. He has made great progress in bridging research areas such as biomedical and bioelectronics as well as artificial intelligence.

If you have ever seen the brain’s neurons under the microscope, there are endless life signals hidden within this network. Let’s explore this and the research of Prof. Sawan's team.

‘Seeing the World’ in 1 Square Millimeter

On Dr. Sawan's desk sits a worn-down plastic storage box the size of the palm of your hand. This seemingly ordinary box holds chips smaller than a fingernail, with extraordinary properties.

In early September, the Royal Society of Canada announced the list of newly elected fellows in 2022. Dr. Sawan was included in the list of 102 new fellows due to his many breakthrough achievements in biomedical engineering.

Prof. Sawan taught at the University of Montreal in Canada for 27 years, serving as assistant professor, associate professor, and professor. From 2001 to 2015, he also served as the Canada research chair in the field of smart medical devices. He also led the strategic alliance on microsystems of Quebec, one of the largest research groups on microsystems in Canada, from 1999 to 2018.

Taking out several of the packaged integrated circuit chips from his plastic box, Dr. Sawan pointed out that the chip cores measure less than 1 square millimeter in the middle. There are very thin metal needles here, some in a 4×4 arrangement, and some in an 8×8 arrangement. These needles are electrodes used to stimulate the visual cortex in the brain.

In theory, the more electrodes there are, the clearer a reconstructed visual image can be, similar to how we evaluate the resolution of the screen of an electronic device. But in reality, the factors that need to be considered are much more complex. More electrodes means higher power consumption, and higher power consumption means a more complex power supply to the device and a higher risk of damage to brain tissue.

According to the design of Dr. Sawan's team, it is necessary to implant multiple such chip-based interfaces in the primary visual cortex of a brain within a safe and controllable range, and then form a complete microsystem with an external camera based miniaturized base station including power supplies and other components. Through this method the team is committed to solve blindness caused by various nerve conduction disorders.

"Until now, human beings have not fully understood everything about vision, but we can at least 'see' the world again through biomedical engineering," Dr. Sawan told us. He explained that although this technology cannot help blind people regain normal vision, at least it can restore some of their vision and allow them to live and work independently.

Stopping the Brain 'Storms'

Epilepsy is a common chronic neurological disease. The seizures associated with epilepsy are repetitive and corresponding foci are unknown, but the currently known pathogenesis is often the abnormal discharge of neurons in a certain location in the brain, which then spreads to other brain areas, resulting in different degrees of symptoms, convulsions and fainting in severe cases.

"It's like setting off a storm in the human brain," Prof. Sawan told us.

How can we predict the coming of this storm in advance, or go further to find the culprit behind this storm and even prevent it?

In 2018, Dr. Sawan came to China and joined the School of Engineering of Westlake University in full-time basis as a chair professor of microsystems and bioengineering. He is focusing his team's work to the introduction of microsystems for epilepsy diagnosis and early warning.

The challenge is that the signals of seizures are complex to understand, as it is the case of all brain related functions. Researchers from Dr. Sawan's team showed us an EEG signal from a real patient before a seizure. To the naked eye, they look almost identical to healthy EEG signals.

The signal of the recorded EEG is at the microvolt level, which is only a few millionths of the voltage of a common battery. Therefore, the process of collecting EEG signals is easily disturbed by the external environment and the electromagnetic field and electronic noise of the detection equipment itself.

The chip they are working on can help locate this faint sound amid the noise.

Since 2018 Sawan’s team has worked on algorithm development, chip design, sample manufacturing and data testing for epilepsy prediction. This chip can do three things: clearly record EEG signals, process the information, and deliver electrical stimulation or drugs when necessary.

Designing a complete set of intelligent closed-loop brain-computer microsystems is their goal. This will help those with epilepsy enjoy a healthy life.

A Unique Perspective on Treating Neurodegenerative Diseases

As a professor with both an academic background in biomedicine and electrical engineering, Prof. Sawan adds an engineering perspective when looking at the diagnosis and treatment of neurodegenerative diseases.

“We think of the brain as a machine,” Sawan observed. “When a function fails, it may be because a component is broken, or it may be because of poor contact between components. One solution is to replace the broken component with a set of microsystems that collect signals, process them, and stimulate intervention.”

With this similar logic, Prof. Sawan's lab conducts research on various neurodegenerative diseases such as Parkinson's and Alzheimer's disease.

Taking the solution for predicting epilepsy as an example, the smart medical devices of Dr. Sawan’s lab involve multidisciplinary fields such as microelectronic integrated circuits, wireless communication, signal processing, microfluidics, micro-nanophotonics, micromachining, and microsystem integration.

The work has many applications, including in vitro diagnosis, disease prediction, and the recovery of bodily functions. This is also the research direction that this team based in China wants to focus on in the future.

After just four years of working in China, Sawan won the Chinese Government’s Friendship Award, the nation’s highest honor to foreign experts, for his outstanding scientific research, as well as the Hangzhou Outstanding Talent Award, the Hangzhou Qianjiang Friendship Messenger Award and the Zhejiang West Lake Friendship Award.

In one of his award acceptance speeches, he expressed:

"The support from all aspects of society has made the dream of Westlake University come true, and it has also made my dream come true. My dream is to use cutting-edge scientific research and technology to help patients with neurodegenerative diseases return to normal life and improve their quality of life."