Flexible Single-Optical-Fibre Endoscope

Recently, researchers at Massachusetts Institute of Technology and Korean University demonstrated a single multimode-optical-fibre (MMF) imaging endoscope. Compared with conventional fibre-bundle based endoscopes, this device is ultra-slim, high-resolution, wide-field, lensless, low cost and disposable. The main drawback of such devices is that they cannot be used as flexible endoscopes due to image blurring caused by fibre-shape variation. However, flexible endoscopes are viewed as most desirable and are widely used in modern healthcare. In order to overcome this problem, this research aims to develop the world's first flexible single-fibre endoscope system by using a novel speckle monitoring technique. The monitoring module will consist of a calibration beam and associated optics to monitor the real-time changes in mode coupling induced by fibre movement and bending. The monitoring results will be used to predict MMF imaging transmission matrix for original image restoration. At the end of the project, a prototype device together with real-time software and algorithms will be developed for potential clinical trials and translational research. The project is highly interdisciplinary: it brings together expertise in the areas of optics, instrumentation, imaging, signal processing and surgery. The outcome of the proposed research has the potential to put the UK at the forefront of a crucial emerging area of new medical devices for modern endoscopy, which is likely to have a huge impact not only on research and patient well-being, but also on the UK and global economy.

i) Healthcare and well-being: The proposed flexible single-fibre endoscope is ultras-slim, high resolution, low cost and disposable. Therefore, such a device is unique in minimally-invasive diagnosis and surgery, and will have a huge impact on healthcare and well-being. Firstly, this is due to not only the growing patient preferences but also those benefits to the healthcare system such as reduced length of stay in the hospital and cost saving, etc. Secondly, in applications such as neurosurgery and urogenital surgery, the smallest possible imaging probe needs to be used due to the nature of the tissues and organs involved. The minimally invasive procedure depends on the size of imaging probe used. The proposed device will make existing minimally-invasive procedures even less invasive. As a result, in-vivo endoscope imaging could be extended to currently unreachable surgery areas. Thirdly, the proposed device has the great potential in early detection of life-threatening diseases such as cancer. It is of vital importance for such diseases to be diagnosed and treated at an early stage, which will greatly reduce trauma and mortality.

ii) Endoscope industry: Endoscopy is the only solution to obtain high-resolution, microscopic images in deep tissues. Since the 1960s, most of minimally-invasive endoscopes have been made of dense bundles of optical fibres. The estimated global market size for endoscope industry will be more than £27 billion in 2020. Of these, flexible endoscope has a share of more than 70%. The proposed flexible single multimode optical fibre (MMF) device will lead to the next generation minimally-invasive high-resolution endoscope devices in this industry. The ultra-thin diameter and high resolution of the proposed device make it perfect for many challenging applications. The low-cost MMF-based endoscope can be disposable, which eliminates the risk of cross-contamination and possible exposure to infectious diseases when reusing the endoscope probe.


iii) Veterinary medicine: Similar as in healthcare, endoscopic procedure is widely used. In particular, for small animals, the miniaturized endoscope probe is the most desirable. The proposed ultra-slim device will have a significant impact in the field of veterinary medicine and will lead to advances in animal researches. Furthermore, the disposable feature is viewed as very appealing by veterinary clinics, as at present the cost for minimally invasive endoscopy probes is too high (above £20k) and the probes will have to be reused for many times usually above their lifetime limit.


iv) Optical Imaging: The miniature-size, super-resolution and flexibility offered by the proposed device are likely to lead to a revolution in probe-based optical imaging. Apart from the endoscopic applications, the diffraction limit resolution of the proposed device makes it very close to a high resolution microscope, and can be used to see very subtle details of materials (e.g. quantum gases) or biological tissues (e.g. single cells in deep tissues). In addition, miniaturized imaging probe have found many applications in industry and research. This include, for example, examination of aircraft combustion and blade chambers, inspection of pipes in oil and energy industry, viewing inside walls and ducts of buildings, internal examination of statues and tombs in archaeology.