Ultrasound Assisted Optical Imaging to Replace Endoscopy in a Revolutionary Discovery

Assistant Professor of Electrical and Computer Engineering (ECE) at Carnegie Mellon University, Maysam Chamanzar, and Ph.D. of ECE Student Matteo Giuseppe Scopelliti today published a research which introduces a new technique that uses ultrasound to take non-invasive optical images through a cloudy medium such as a biological tissue to image the body's organs. This new method could eliminate the need for invasive visual exams using endoscopic cameras.

In other words: one day, it may no longer be necessary to insert oscilloscopes into the body, for example in the throat or under the skin, to reach the stomach, brain or any other organ.

Endoscopic imaging, or the use of cameras inserted directly into the body's organs to study the symptoms, is an invasive procedure used to examine and diagnose symptoms of deep tissue disease. Endoscopic imagers or cameras placed at the end of catheter tubes or wires are usually implanted by means of a medical procedure or a surgical procedure in order to reach the deep tissues of the body, but the new Chamanzar technique offers a totally non-surgical and non-invasive alternative.

The article in the lab published in Light: science and applications, a journal published by Springer Nature, shows that they can use ultrasound to create a virtual "lens" in the body, rather than implanting a physical lens. By using ultrasound wave models, researchers can effectively "focus" light in the tissues, allowing them to take previously unreachable images in non-invasive ways.

Biological tissues are able to block most of the light, especially that located in the visible range of the optical spectrum. Therefore, current optical imaging methods can not use light to access deep tissues of the surface. The Chamanzar laboratory, however, has used non-invasive ultrasound to induce more transparency and allow greater penetration of light in murky environments, such as biological tissues.

"Being able to relay images of organs such as the brain without the need to insert physical optical components will be an important alternative to the implantation of invasive endoscopes in the body," says Chamanzar. "We have used ultrasound to carve a virtual optical relay lens in a given target holder, which can be a biological tissue, for example, so this tissue is transformed into a lens that helps us capture and relay images of more complex structures. This method can revolutionize the field of biomedical imaging.

Ultrasound waves are able to compress and rarefy, or thin, regardless of the environment in which they pbad. In compressed regions, light moves more slowly than rarefied regions. In this article, the team shows that this compression and rarefaction effect can be used to sculpt a virtual lens in the target medium for optical imaging. This virtual lens can be moved without disturbing the support simply by reconfiguring the ultrasonic waves from the outside. This allows imaging of different target regions, all non-invasively.

The published method is a platform technology that can be applied to many different applications. In the future, it can be implemented in the form of a portable device or a portable surface patch, depending on the imaged organ. By placing the device or patch on the skin, the clinician would be able to easily receive optical information from the inside of the tissues to create images of what's inside without the many disadvantages and side effects of endoscopy.

The current applications closest to this technology would be the endoscopic imaging of brain tissue or imaging under the skin, but this technique can also be used in other parts of the body for the purpose. imaging. Beyond biomedical applications, this technique can be used for optical imaging in machine vision, metrology and other industrial applications to allow non-destructive and orientable imaging of objects and objects. structures at the micron scale.

Researchers have shown that the properties of the virtual "lens" can be adjusted by changing the parameters of the ultrasound waves, allowing users to "focus" the images taken with the process at different depths of the medium. While the LSA This paper focuses on the effectiveness of the method for applications closer to the surface. The team has not yet determined the depth limit of body tissues by this method of ultrasound-badisted optical imaging.

"What distinguishes our work from conventional acousto-optical methods is that we use the target medium itself, which can be a biological tissue, to affect the light when it propagates through the medium." "says Chamanzar. "This in situ interaction provides opportunities to counterbalance the non-idealities that disrupt the trajectory of light."

This technique has many potential clinical applications, such as the diagnosis of skin diseases, surveillance of brain activity, diagnosis and photodynamic therapy for the identification and targeting of malignancies.

In addition to the direct implications of this research on clinical medicine, it will also have indirect clinical applications. Using this acousto-optic technology to visualize patterns of brain disorders in mice and selectively stimulate different neuronal pathways, researchers would be able to study the mechanisms involved in diseases such as Parkinson's disease, by illuminating the design of next-generation clinical therapeutic interventions to treat these diseases in humans.

"Turbid media have always been seen as barriers to optical imaging," says Scopelliti. "But we have shown that such media can be converted into allies to help light reach the desired target.When we activate the ultrasound with the appropriate pattern, the cloudy medium becomes immediately transparent.It is exciting to think about the potential impact of this method on a wide range of areas, from biomedical applications to computer vision ".