machine learning-based tag-free histopathology device operates in real time | Research & Technology | November 2021



POHANG, South Korea, November 4, 2021 – Researchers at Pohang University of Science and Technology (POSTECH) and Gachon University College of Medicine (South Korea) have developed a device that eliminates the need for complex procedures such as freezing, cutting and staining in the process of histopathology. The device is part of a system that uses ultraviolet microelectromechanical photoacoustic imaging microscopy (UV-MEMS PAM) technology.

Using a MEMS scanner capable of rapidly scanning light and sound waves, South Korean researchers performed a high-speed pathological biopsy on resected clinical tissue from cancer patients. Courtesy of POSTECH.

The diagnosis of cancer is confirmed by histopathology by removing part of the tissue in question, after tests such as MRI, CT, ultrasound or endoscopy. Based on the clinical diagnosis, the cancerous tissue is surgically removed and the suspicious tissue or lymph nodes are further examined. Medical staff can then formulate treatment plans and / or perform chemotherapy and radiation therapy based on these results.

The machine-learning-based histopathology approach uses a single-axis MEMS scanner as a novel method of intraoperative histopathology without a tag. In cancer resection surgery, hhistopathological examination is essential to confirm the site of a tumor. The frozen section test has conventionally been used to perform the examination, but due to its complicated process, it can prolong surgery and potentially cause misinterpretation.

Using a MEMS scanner in the newly developed approach, the researchers were able to visualize marker-free cell nuclei in murine and human tissues. By imaging resected clinical specimens from actual cancer patients and numerically quantifying the histopathological findings, the team demonstrated the potential of the proposed UV-PAM system as an alternative method of intraoperative histopathology.

Photoacoustic imaging enables 3D imaging without an independent contrast agent. It further combines the advantages of high resolution optical imaging with ultrasound imaging which provides structural and functional imaging from small cells and living tissues to large organs.

The microscope developed as part of the work in progress uses a high-speed MEMS scanner to dramatically improve imaging speed, distinguishing normal tissue from cancerous tissue by performing photoacoustic histopathology on cancerous tissue that is excised from real cancer patients , and quantifying pathological microstructures, said Professor Chulhong. Kim, who heads the bio-optics and acoustics laboratory at POSTECH.

The research was published in Lasers and Photonics Reviews (



Leave A Reply