Sizing the aortic annulus with a robotised, commercially available soft balloon catheter: in vitro study on idealised phantoms

Abstract

Transcatheter aortic valve implantation (TAVI) is a minimally invasive surgical technique to treat aortic heart valve diseases. According to current clinical guidelines, the implanted prosthetic valve replacing the native one is selected based on pre-operative size assessment of the aortic annulus through different imaging techniques. That very often leads to suboptimal device selection resulting in major complications, such as prosthetic valve leakage or interruption of the cardiac electrical signal. In this paper, we propose a new, intra-operative approach to determine the diameter of theaortic annulus exploiting intraballoon pressure and volume data, acquired from a robotised valvuloplasty balloon catheter. An inflation device, capable of collecting real-time intra-balloon pressure and volume data, was designed and interfaced with a commercially available valvuloplasty balloon catheter. A sizing algorithm allowing to precisely estimate the annular diameter was integrated. The algorithm relies on a characterised analytical model of the balloon free inflation and an iterative method based on linear regression. In vitro tests were performed on idealised aortic phantoms. Experimental results show that pressure-volume data can be used to determine annular diameters bigger than the unstretched diameter of the balloon catheter. For these cases, the proposed approach exhibited good precision (maximum average error 0.93%) and good repeatability (maximum standard deviation ±0.11 mm).

Patient-Specific Aortic Phantom With Tunable Compliance

“…Increasingly high level of surgical skills and experience is required to successfully perform cardiovascular interventions, due to the growing variety of medical devices to treat CVD, the intrinsic complexity of interventions, and the lack of sufficient training and adequate surgical planning. In particular, in minimally invasive interventions where the procedures are image guided, such as transcatheter aortic valve implantation [12,13], coronary stent implantation [14] or aortic endografting [15,16], relevant skills and experience are of paramount importance. In these cases, the anatomical complexity, malpositioning, or migration of prosthetic devices affects the outcome of the treatment and may lead to the conversion to invasive surgery [17,18].…”

Screw theory-based stiffness analysis for a fluidic-driven soft robotic manipulator

“…Actuation systems for soft robots can be classified into three categories: tendon-, fluidic-and electro-active polymerdriven actuation [7]. In particular, fluidic-driven robots are rather cost-efficient and have been extensively explored for applications in the industrial sector where robots work closely together with humans [8], [9], in minimally invasive interventions [10]- [13], and rehabilitation [14]. However, as a result of their inherently soft property, the ability to exert forces on the environment, when required, and effectively change the stiffness on demand is challenging and yet to be further explored [15]- [17].…”

Dynamic modelling and visco-elastic parameter identification of a fibre-reinforced soft fluidic elastomer manipulator

“…Soft material robotics has become an important research topic [12], [13] aiming at a wide range of applications [14]- [16]. Many fluidic-driven soft robots are made of elastomer materials, which exhibit visco-elastic behaviour, which needs to be incorporated in the model.…”