Molecularly aware robotics for surgery (MARS)

Lead Research Organisation: Imperial College London
Department Name: Metabolism, Digestion and Reproduction

Abstract

Summary
The proposed project is aimed at the development of a semi-autonomous surgical robotics platform for the removal of tumours with unprecedented accuracy. Currently, when surgeons remove tumours, they use information collected before the surgery (ultrasound, X-ray) to locate the tumour and assess its actual extension based on what they see or feel with their fingertips. Unfortunately, it is almost impossible to tell healthy tissue from cancer-infiltrated tissue by its look, which results in lengthy operations including the careful examination of removed tissues under microscope to avoid cancer cells left behind causing local regrowth of the tumour. Since the surgical team can only examine cells which are already removed, even this approach cannot fully guarantee the complete removal of cancerous tissue. The proposed technology offers an alternative, where the surgical tool - in the current case a superfine surgical laser - is combined with a powerful microscope and a molecular analysis device. These two devices together can unambiguously identify cancerous cells and they can subsequently be evaporated using the surgical laser. While the cell-by-cell removal of a tumour may sound attractive, especially in the aspect of sparing all non-cancerous cells, at the practical level human beings cannot perform such operations as even if we assume that a surgeon can identify and remove a cell in a second, the complete elimination of small tumour would still take weeks of continuous work. However, if both the identification and the firing of the laser is performed by an artificial intelligence, this time can be reduced to tens of minutes - a commonly accepted timeframe for minor surgeries.
The proposed surgical robot will look like a little tent set up over the tumour. The enclosure will house a fibre-like probe, which contains the laser, the microscope and the molecular analysis tools. The computer will be able to direct the probe at any point of the tumour with cellular precision or scan tens of mm2 area in a second. When the device is set up, it localises the tumour at first using the microscopic device, then evaporates the bulk, continuous tumour tissue, while continuously looking for signs of healthy cells with the molecular sensing tool. At the edge of the tumour it will use the microscope to find potentially cancerous cells and will properly identify them using the molecular information before removing them. The surgeon oversees the process and gives directions to the computer regarding the areas to find tumour cells and other surgical steps e.g. coagulation of minor bleeds on the surgical area.
The technology will significantly increase the accuracy of cancer surgery, will make currently inoperable cases operable, decrease reoperation rate by eliminating local regrowth and minimise the complications of cancer surgery. In addition, it will give an opportunity for the healthcare providers to turn most cancer surgeries into outpatient interventions performed at outpatient clinics or even at GP surgeries. As the device will give diagnostic information itself, the detection-diagnostics-removal journey for e.g. a skin cancer will take half an hour at the GP in contrast to the current several weeks involving multiple hospital visits.
 
Description Our research team has successfully developed a hybrid robotic platform combining the capabilities of two distinct robot systems: a hydraulic-actuated robot and an electrothermally actuated fibre-based robot. This innovative platform enables high-precision surgical laser ablation and information interaction with a tissue identification system to create a tissue diagnostic map. This robotic platform was demonstrated through an experiment on mouse skin tissue samples with several cancerous lesions.
The hydraulic actuated robot is a parallel manipulator that employs hydraulic actuators to pull tendons attached to its shaft. A miniaturised camera set with a marker-based tracking mechanism was developed to track the position of the robot shaft, which is used for the visual-feedback control of the robot's motion. With a large workspace (larger than 5 cm x 5 cm), the hydraulic robot was used for the gross positioning of the fibre robot.
The electrothermally actuated fibre-based robot was fabricated using a highly scalable fibre drawing technique. This fibre robot is actuated using the non-uniform thermal expansion of the tubular polymer structure, induced by localised heating generated by powered resistive wires. Precise control over the current applied to these wires enables the fibre robot to achieve high-precision scanning motion (tens of micrometres).
By integrating these two robot systems and enabling their interactive collaboration, a specified scanning strategy with high precision in a large area was realised: The hydraulic robot delivers the fibre robot to do a large range raster scan, while the fibre robot performs a continuous line scan to cover the gap between two adjacent lines of the raster. Additionally, the laser fibre was integrated with the robotic platform to perform high-precision ablation on the tissue sample. A suction tube was integrated into the robotic system to transfer the aerosol generated from ablated tissue to the rapid evaporative ionisation mass spectrometry (REIMS) system.
The experimental validation of the hybrid robotic platform was carried out on mouse skin tissue samples (including several cancerous lesions), and the tissue classification model was built using the REIMS system. A diagnostic tissue map was created by integrating the real-time tissue information of the ablating position and robot ablation position. Furthermore, the current hybrid robot collaboration control mechanism facilitated a secondary ablation scan on the tumour region of the tissue map, where the hydraulic robot delivered the fibre robot to the tumour area, and the fibre robot performed a high-precision raster scan. Continuous communication was established between the robotic and the REIMS systems, and instantaneous identification of healthy and cancerous tissue was demonstrated during the scan.
The majority of the objectives were accomplished. The integration of the confocal microscopy system requires more work to overcome the friction for clear image acquisition. The basic framework for the autonomous disease removal approach has been established with the development of robotic systems and their corresponding algorithms. We are working on demonstrating it in the last weeks of this grant. We also have expanded our network to allow us access to a larger tissue sample set. Further grant opportunities are being explored with our new collaborators.
Exploitation Route The funding was used for Phase 1 of the project, for the development and ex vivo validation of the prototype fibrebot. We have applied and awarded further funding to initiate Phase 2, which will focus on the clinical translation of the fibrebot, so we will continue working on the project for the benefit of the society and scientific community. It is a natural next step to use robotic devices to guide diagnostic instruments and this project provides a means of achieving that. The capability to precisely scan large areas of tissue and create diagnostic maps has value in many different applications beyond the ones this project has investigated.
Sectors Healthcare,Other

URL https://www.biorxiv.org/content/biorxiv/early/2023/02/16/2023.02.16.528823.full.pdf
 
Description We are building a network of clinicians motivated by our demonstrations, observing the potential cost and time savings, and reducing the burden of the disease on patients and the healthcare system, bringing more equal treatment opportunities to patients.
Sector Healthcare,Other