]The activities of the PROCT projects were organized into two phases: the first dedicated to establishing the baseline system and the second addressing the improvements to achieve real-time images of the volume needed for histopathological examination.
The second phase is dedicated to the improvement of the baseline system to achieve data acquisition and storage compatible with the faster acquisition speed needed of the real-time procedure.
In parallel to the technical activities, an assessment and validation study was carried out to determine the effectiveness of the project outcomes, focusing on the following key enablers:
1. Evidence-based clinical efficacy, based on tests on phantoms to validate the diagnostic accuracy of the technology and to prove its safety.
2. Assessment of the economic and societal benefits by carrying out a preliminary Health Technology Assessment (HTA) of the technology.
During the first phase of the project, it was decided to contract the development of a custom OCT system to have the freedom to adjust the parameters and to incrementally develop it to achieve the desired performance. A contract was given to the Austrian company ACMIT Gmbh to study the design of a modular experimental OCT that would allow to test different hardware and software solutions.
The system developed and delivered allows the acquisition of A-scans with a focal spot diameter of about 30μm and an axial resolution of about 10μm. The scanning depth is about 1-2mm (depending on the type of tissue, vascularization, etc). Increase of resolution (toward 5μm approximately) would be possible by selection of different components for the OCT generator, but at the cost of imaging depth. Similarly, also the imaging depth could be increased to 2-3mm - but at the cost of resolution. The setting with 10μm axial resolution and 1-2mm scanning depth was selected. The OCT system developed is a Common Path OCT (CP-OCT) type. The advantage of such a CP-OCT is that it automatically adjusts to variations in fiber length which is very important to compensate a variation of the fiber length due to different bending of the fiber during measurement. The needle is equipped with a “side fire” setup to collect data on the cylinder surrounding the needle during the insertion.
The system consists of a controlling computer, the optical signal generation and data acquisition, the fiber-needle assembly and the needle advancement system. The side-fire needle is unique to this prototype and it allows side image acquisition at the expense of some attenuation of the signal due to deflected optical path. The needle advancement system consists of a linear and a circular stage that allow the needle to inserted in the tissue following a spiral path. This system is the baseline system that is used to acquire competence in using OCT data and in developing the necessary modifications for its use in clinical practice.
The system software is responsible for comprehensive signal processing, which includes the extraction of A-scan images, the assembly of these images into B-scan images, and further synthesis into three-dimensional C-scan images. Ultimately, artificial intelligence algorithms will be employed to process the derived images, ensuring that both the images and analytical results are efficiently presented to the user.
During the second phase of the project (still on going), we started to improve the non-real time baseline system, which is limited in image production. The main modifications include the increase of the scanning speed by changing the controlling code (modification made by ACMIT) and enhancing the hardware and software to support real-time data acquisition and processing. To improve the scanning speed the computer currently used for signal and software processing will be replaced with an FPGA and embedded processor. This change will facilitate faster signal processing, data handling, and AI algorithm execution in a real-time system. We conduct a feasibility study for this approach and, after confirming the feasibility of implementation, we proceeded with designing and testing the system.
In parallel to the technical activities the (Freedom to Operate) FTO and (Health Technology Assessment) HTA analyses were performed.
The FTO analysis identified six relevant patent families, each disclosing features related to the PROCT development.
As a preliminary validation of the business feasibility, a Health Technology Assessment (HTA) was conducted to evaluate the expected economic and social benefits for national health systems and patients.
