Robot-guided osteotomy in fibula free flap mandibular reconstruction: a preclinical study.

Various methods currently exist to guide fibular osteotomy positioning in fibula free flap mandibular reconstruction, but patient-specific navigation methods and cutting guides require experience, and may be time-consuming and/or expensive. This study describes a robot-guided osteotomy technique for mandible reconstruction using a fibula free flap according to virtual preoperative planning. The method was assessed on five 3D-printed models and a cadaveric model. The precision of the robot-guided osteotomy was evaluated by measuring the deviations between the lengths and angles of the fragments obtained and those of the virtual planning. The average deviation of the anterior and posterior crest lengths was 0.42 ± 0.29 mm for the 3D-printed models and 1.00 ± 0.53 mm for the cadaveric model. The average angle deviation was 1.90 ± 1.22° and 1.94 ± 0.69° for the 3D-printed and cadaveric models, respectively. The results of this preclinical study revealed that fibular osteotomy positioning guidance using a robot-positioned cutting guide may be a precise, easy-to-use technique that could be tailored for fibula free flap mandibular reconstruction.

An open-source and easily replicable hardware for Electrical Impedance Tomography.

Electrical Impedance Tomography (EIT) is a powerful imaging tool for investigating electrical properties of tissues such as that of human bodies. The cheap, harmless and portable nature of this tool has made EIT a popular choice in many biomedical applications. However, performing EIT requires strong development at both hardware and software levels. In particular, performing in-lab experiences remains a challenge due to the cost of commercially available devices or the complexity of systems proposed in scientific literature. In this paper, an efficient and easily replicable EIT hardware is presented. This hardware was developed with the objective of making EIT accessible to as many people as possible. It has been designed for operating frequencies between 1 kHz and 50 kHz, and can be used for in-lab validation of proof of concept. Special care has been paid to the choice of components in order to optimize the performance versus cost ratio. Also, the overall footprint has been reduced by using recent and up-to-date integrated circuits. In particular, the use of a lock-in amplifier is a compact solution that allows both narrow-band filtering of the signal and provides an easily quantifiable DC signal at the output. Circuit schematics as well as manufacturing files are shared so that understanding, replication and improvement of circuits are facilitated. Fabrication and usage procedures are given as well. At last, the proposed hardware is experimentally tested and validated first by comparing experimental data to simulations, then by reconstructing an inclusion in biological tissues.

Electrical impedance tomography: a potential tool for intraoperative imaging of the tongue base.

Background. The presence of a tumor in the tongue is a pathology that requires surgical intervention from a certain stage. This type of surgery is difficult to perform because of the limited space available around the base of the tongue for the insertion of surgical tools. During the procedure, the surgeon has to stretch and then fix the tongue firmly in order to optimize the available space and prevent tissue movement. As a result, the preoperative images of the inside of the tongue no longer give a reliable indication of the position and shape of the cancerous tissue due to the deformation of the overall tissue in the area. Thus, new images are needed during the operation, but are very difficult to obtain using conventional techniques due to the presence of surgical tools.Objective. Electrical Impedance Tomography (EIT) is an imaging technique that maps the resistivity or difference of resistivity of biological tissues from electrical signals. The small size of the electrodes makes it a potentially interesting tool to obtain intraoperative images of the inside of the tongue. In this paper, the objective is to study the possibility of using EIT for this purpose is investigated.Main results. A detection method is proposed, including an original configuration of the electrodes, consistent with the anatomical specificities of the tongue. The proposed method is studied in simulation and then a proof of concept is obtained experimentally on a 3D printed test tank filled with saline solution and plant tissue.