At the moment, surgeons struggle curing a widespread eye disease known as retinal vein occlusion where clots obstruct the retinal vessels. Latter vascular disorder involves black spots in people's eyesight and lead eventually to blindness. A recent promising treatment consists in flushing a thrombolytic agent inside the clotted retinal vessels. The surgery implies puncturing vessels ranging from 50 to 400 microns diameter on the backside of the eye, namely the retina. Latest research succeeded in tackling several challenges around this operation: the surgeon's hand tremor and the high precision required amongst other requirements. Despite several breakthroughs, the surgeon only relies on a microscope to perform the surgery through the patient eye's lens, giving poor depth perception to properly puncture the retinal vessels. This way, the surgeon is most likely to pierce through the vessel and inject the thrombolytic drug under the retina, which would endanger the person's eyesight. In this paper, we investigate the use of a novel bio-impedance sensor developed for eye surgery. Together with this new sensor, a detection algorithm has been developed to detect the puncture and double puncture events to give a feedback to the operator of the system. As far as we are aware of, such technology doesn't exist yet in eye surgery to tackle the depth perception question. This paper aims at demonstrating the benefits of this technology.

Retinal Vein Occlusion is a common retinal vascular disorder which can cause severe loss of vision. Retinal vein cannulation followed by injection of an anti-coagulant into the affected vein is a promising treatment. However, given the scale and fragility of the surgical workfield, this procedure is considered too high-risk to perform manually. A first successful robot-assisted procedure has been demonstrated. Even though successful, the procedure remains extremely challenging. This paper aims at providing a solution for the limited perception of instrument-tissue interaction forces as well as depth estimation during retinal vein cannulation. The development of a novel combined force and distance sensing cannulation needle relying on Fiber Bragg grating (FBG) and Optical Coherence Tomography (OCT) A-scan technology is reported. The design, the manufacturing process, the calibration method, and the experimental characterization of the produced sensor are discussed. The functionality of the combined sensing modalities and the real-time distance estimation algorithm are validated respectively on in-vitro and ex-vivo models.

Retinal Vein Occlusion is a common retinal vascular disorder which can cause severe loss of vision. Retinal vein cannulation and subsequent injection of anti-coagulant in the affected vein is a promising treatment. Given the scale and the fragility of retinal veins on one side and the surgeons limited positioning precision and force perception on the other side, this procedure is considered too risky to perform manually at the moment. The paper tackles the limited force perception problem. The development of a novel force sensing cannulation needle based on Fiber Bragg Gratings is reported. The design, the calibration method and the experimental characterization of the produced force sensor are discussed. The functionality of the needle is validated by measuring puncture forces during cannulations in a custom-made retina model.

Advances in miniature surgical instrumentation are key to less invasive and safer medical interventions. In cardiovascular procedures interventionalists turn towards catheter-based interventions, treating patients considered unfit for classical more invasive approaches. Improvements in design and steerability of catheters could further reduce the invasiveness of these interventions. For example, by improving controllability and interaction forces with the vessels, tissue damage could be limited. Through improved steerability and coordinated control, operation times and exposure to radiation might also be reduced. Latter argument formed the original motivation for the development of teleoperated robotic catheters. Despite the large kinematic dissimilarity and thus non-trivial mapping between joystick input and catheter output motion, few investigations have been conducted to find intuitive mappings that allow straightforward catheter steering. This paper presents some recent work in this direction. Three promising mappings are proposed. The mappings were implemented and validated upon a robotic catheter moving inside an artificial aorta model. Experimental results show good steerability of the robotic catheter for all the mappings. Although superiority of one mapping with respect to the others was observed, further investigation and validation is planned. In the future, additional visual cues that increase the situational awareness of the user are expected to further simplify the steering.

Retinal surgery is one of the most challenging types of surgery because of the scale and the fragility of the human eye anatomy. The surgeon suffers from limited positioning accuracy, tremor and poor force feedback directly affecting the quality of the surgical procedures. To tackle these issues, we developed a teleoperation system to assist surgeons during retinal surgery. The system offers features like motion scaling, tremor compensation and scaled force feedback. This paper reports on the design of the slave and the master.

Retinal Vein Occlusion (RVO) is a common retinal vascular disorder which may cause severe loss of vision. Retinal cannulation appears to be the most effective treatment, but given the small diameter of a retinal vein, it is too difficult and risky for a surgeon to perform this procedure manually. This work reports on the development of an innovative robotic manipulator to assist vitreoretinal surgeons during this procedure using a co-manipulation control strategy. The robotic manipulator features a new Remote-Center-of-Motion mechanism with four degrees of freedom. This mechanism is particularly interesting for applications in minimally invasive surgery where an instrument needs to be manoeuvred in a highly confined space around a fixed incision point. The developed manipulator is shown to be a great asset in improving the quality of retinal cannulations compared to the manual procedure. This is shown by cannulation experiments performed on a custom made eye model and an injectable retina model that effectively simulate real retinal cannulations.