Selene Tognarelli

Searching for the Perfect Wave: The Effect of Radiofrequency Electromagnetic Fields on Cells

There is a growing concern in the population about the effects that environmental exposure to any source of “uncontrolled” radiation may have on public health. Anxiety arises from the controversial knowledge about the effect of electromagnetic field (EMF) exposure to cells and organisms but most of all concerning the possible causal relation to human diseases. Here we reviewed those in vitro and in vivo and epidemiological works that gave a new insight about the effect of radio frequency (RF) exposure, relating to intracellular molecular pathways that lead to biological and functional outcomes. It appears that a thorough application of standardized protocols is the key to reliable data acquisition and interpretation that could contribute a clearer picture for scientists and lay public. Moreover, specific tuning of experimental and clinical RF exposure might lead to beneficial health effects.

Magnetic propulsion and ultrasound tracking of endovascular devices

In this paper a robotic means of magnetic navigation of an endovascular device a few millimeters in diameter is presented. The technique, based on traditional computer-assisted surgery adapted to intravascular medical procedures, includes a manipulator for magnetic dragging interfaced with an ultrasound system for tracking the endovascular device. The main factors affecting device propulsion are theoretically analyzed, including magnetic forces, fluidic forces, and friction forces between the endovascular device and the vessel. A dedicated set-up for measuring locomotion, and for navigation with and against the flow, has been developed and preliminary tests have been performed to derive the best configuration for controlled magnetic dragging in the vascular system. Experimental outcomes are consistent with a simple analytical model that analyzes dragging of the magnetic capsule in a tube. By means of this model, different working conditions can be considered to select the appropriate conditions, for example flow rate, coefficient of friction, or magnetic properties.

Anchoring frame for intra-abdominal surgery

Natural orifice transluminal endoscopic surgery (NOTES) is one of the modern surgical techniques that led to the miniaturization of surgical tools and brings the concept of inserting many robotic units into the peritoneal cavity for executing “scarless” surgical tasks. However, the development of transabdominal anchoring systems that guarantee stability is recognized as a challenging issue in the design of miniature intra-abdominal robotic devices. A dedicated platform, exploiting magnetic coupling for anchoring, has been designed by respecting anatomical constraints, maximizing the volume to increase the number of embedded magnets, and consequently incrementing operating distance. The device is equipped with a SMA (shape memory alloy) mechanism that allows configuration change from an extended cylindrical (compliant for deployment) to a compact triangular (rigid for providing stability) design. The feasibility and the potential of the proposed platform have been demonstrated both in in vitro and in in vivo conditions on a human phantom and a porcine model, respectively.

A modular magnetic platform for natural orifice transluminal endoscopic surgery

Modern surgery is currently developing NOTES (Natural Orifice Translumenal Endoscopic Surgery) robotic approaches to enable scarless surgical procedures. Despite of the variegated devices proposed, they still have several limitations. In this work, we propose a surgical platform composed of specialized modules, in order to provide the overall system with adequate stability, dexterity and force generation. The concept behind the platform, the main modules and their performance are described to highlight the system potential to outperform current NOTES procedures.

A pilot study on a new anchoring mechanism for surgical applications based on mucoadhesives

Abstract In order to minimize the invasiveness of laparoscopic surgery, different techniques are emerging from research to clinical practice. Whether the incision is performed on the outside – as in Single Port Laparoscopy (SPL) – or on the inside – as in Natural Orifice Transluminal Endoscopic Surgery (NOTES) – of the patients body, inserting and operating all the instruments from a single access site seems to be the next challenge in surgery. Magnetic guidance has been recently proposed for controlling surgical tools deployed from a single access. However, the exponential drop of magnetic field with distance makes this solution suitable only for the upper side of the abdominal cavity in nonobese patients. In the present paper we introduce a polymeric anchoring mechanism to lock surgical assistive tools inside the gastric cavity, based on the use of mucoadhesive films. Mucoadhesive properties of four formulations, with different chemical components and concentration, are evaluated by using both in vitro and ex vivo test benches on porcine stomach samples. Hydration of mucoadhesive films by contact with the aqueous mucous layer is analyzed by means of in vitro swelling tests, whereas optimal preloading conditions and adhesion performances, in terms of detachment force, supported weight and size are investigated ex vivo. Mucoadhesion is observed with all the four formulations. For a contact area of 113 mm2, the maximum normal and shear detachment forces withstood by the adhesive film are 2,6 N and 1 N respectively. These values grow up to 12,14 N and 4,5 N when the contact area increases to 706 mm2. Lifetime of the bonding on the inner side of the stomach wall was around two hours. Mucoadhesive anchoring represents a fully biocompatible and safe approach to deploy multiple assistive surgical tools on mucosal tissues by minimizing the number of access ports. This technique has been quantitatively assessed ex vivo for anchoring on the inner wall of the gastric cavity or in gastroscopic surgery. By properly varying the chemical formulation, this approach can be extended to other cavities of the human body.

A scalable platform for biomechanical studies of tissue cutting forces

This paper presents a novel and scalable experimental platform for biomechanical analysis of tissue cutting that exploits a triaxial force-sensitive scalpel and a high resolution vision system. Real-time measurements of cutting forces can be used simultaneously with accurate visual information in order to extract important biomechanical clues in real time that would aid the surgeon during minimally invasive intervention in preserving healthy tissues. Furthermore, the in vivo data gathered can be used for modeling the viscoelastic behavior of soft tissues, which is an important issue in surgical simulator development. Thanks to a modular approach, this platform can be scaled down, thus enabling in vivo real-time robotic applications. Several cutting experiments were conducted with soft porcine tissues (lung, liver and kidney) chosen as ideal candidates for biopsy procedures. The cutting force curves show repeated self-similar units of localized loading followed by unloading. With regards to tissue properties, the depth of cut plays a significant role in the magnitude of the cutting force acting on the blade. Image processing techniques and dedicated algorithms were used to outline the surface of the tissues and estimate the time variation of the depth of cut. The depth of cut was finally used to obtain the normalized cutting force, thus allowing comparative biomechanical analysis.

A miniaturized robotic platform for natural orifice transluminal endoscopic surgery: in vivo validation

AbstractBackgroundNatural orifice transluminal endoscopic surgery (NOTES) involves accessing the abdominal cavity via one of the body natural orifices for enabling minimally invasive surgical procedures. However, the constraints imposed by the access modality and the limited available technology make NOTES very challenging for surgeons. Tools redesign and introduction of novel surgical instruments are imperative in order to make NOTES operative in a real surgical scenario, reproducible and reliable. Robotic technology has major potential to overcome current limitations.MethodsThe robotic platform described here consists of a magnetic anchoring frame equipped with dedicated docking/undocking mechanisms to house up to three modular robots for surgical interventions. The magnetic anchoring frame guarantees the required stability for surgical tasks execution, whilst dedicated modular robots provide the platform with adequate vision, stability and manipulation capabilities. ResultsPlatform potentialities were demonstrated in a porcine model. Assessment was organized into two consecutive experimental steps, with a hybrid testing modality. First, platform deployment, anchoring and assembly through transoral–transgastric access were demonstrated in order to assess protocol feasibility and guarantee the safe achievement of the following experimental session. Second, transabdominal deployment, anchoring, assembly and robotic module actuation were carried out.Conclusions This study has demonstrated the feasibility of inserting an endoluminal robotic platform composed of an anchoring frame and modular robotic units into a porcine model through a natural orifice. Once inserted into the peritoneal cavity, the platform provides proper visualization from multiple orientations. For the first time, a platform with interchangeable modules has been deployed and its components have been connected, demonstrating in vivo the feasibility of intra-abdominal assembly. Furthermore, increased dexterity employing different robotic units will enhance future system capabilities.

An active one-lobe pulmonary simulator with compliance control for medical training in neonatal mechanical ventilation

Mechanical ventilation is a current support therapy for newborns affected by respiratory diseases. However, several side effects have been observed after treatment, making it mandatory for physicians to determine more suitable approaches. High fidelity simulation is an efficient educational technique that recreates clinical experience. The aim of the present study is the design of an innovative and versatile neonatal respiratory simulator which could be useful in training courses for physicians and nurses as for mechanical ventilation. A single chamber prototype, reproducing a pulmonary lobe both in size and function, was designed and assembled. Volume and pressure within the chamber can be tuned by the operator through the device control system, in order to simulate both spontaneous and assisted breathing. An innovative software-based simulator for training neonatologists and nurses within the continuing medical education program on respiratory disease management was validated. Following the clinical needs, three friendly graphic user interfaces were implemented for simulating three different clinical scenarios (spontaneous breathing, controlled breathing and triggered/assisted ventilation modalities) thus providing physicians with an active experience. The proposed pulmonary simulator has the potential to be included in the range of computer-driven technologies used in medical training, adding novel functions and improving simulation results.

MEchatronic REspiratory System SImulator for Neonatal Applications (MERESSINA) project: a novel bioengineering goal

Respiratory function is mandatory for extrauterine life, but is sometimes impaired in newborns due to prematurity, congenital malformations, or acquired pathologies. Mechanical ventilation is standard care, but long-term complications, such as bronchopulmonary dysplasia, are still largely reported. Therefore, continuous medical education is mandatory to correctly manage devices for assistance. Commercially available breathing function simulators are rarely suitable for the anatomical and physiological realities. The aim of this study is to develop a high-fidelity mechatronic simulator of neonatal airways and lungs for staff training and mechanical ventilator testing. The project is divided into three different phases: (1) a review study on respiratory physiology and pathophysiology and on already available single and multi-compartment models; (2) the prototyping phase; and (3) the on-field system validation.

A novel simulator for mechanical ventilation in newborns: MEchatronic REspiratory System SImulator for Neonatal Applications.

Respiratory problems are among the main causes of mortality for preterm newborns with pulmonary diseases; mechanical ventilation provides standard care, but long-term complications are still largely reported. In this framework, continuous medical education is mandatory to correctly manage assistance devices. However, commercially available neonatal respiratory simulators are rarely suitable for representing anatomical and physiological conditions; a step toward high-fidelity simulation, therefore, is essential for nurses and neonatologists to acquire the practice needed without any risk. An innovative multi-compartmental infant respirator simulator based on a five-lobe model was developed to reproduce different physio-pathological conditions in infants and to simulate many different kinds of clinical scenarios. The work consisted of three phases: (1) a theoretical study and modeling phase, (2) a prototyping phase, and (3) testing of the simulation software during training courses. The neonatal pulmonary simulator produced allows the replication and evaluation of different mechanical ventilation modalities in infants suffering from many different kinds of respiratory physio-pathological conditions. In particular, the system provides variable compliances for each lobe in an independent manner and different resistance levels for the airway branches; moreover, it allows the trainer to simulate both autonomous and mechanically assisted respiratory cycles in newborns. The developed and tested simulator is a significant contribution to the field of medical simulation in neonatology, as it makes it possible to choose the best ventilation strategy and to perform fully aware management of ventilation parameters.