Progettazione e caratterizzazione di un sistema idraulico di attuazione per strumentazione chirurgica mininvasiva

Il seguente lavoro di tesi fa parte di un progetto di collaborazione tra il laboratorio CRIM della Scuola Superiore Sant’Anna e la Intuitive Surgical Inc., azienda californiana leader mondiale nella robotica chirurgica. L'obiettivo di tale progetto è quello di sostituire l’attuazione a cavi, sinora utilizzata per il polso del braccio robotico del da Vinci, con metodologie innovative in grado di garantire elevate prestazioni (in termini di potenza trasmissibile e range di movimento) in strutture miniaturizzate complesse. In particolare, lo studio propone di progettare e realizzare un circuito idraulico capace di attuare un giunto espandibile a catena ad 1 DOF per applicazioni in chirurgia robotica mininvasiva. L'elaborato è suddiviso in sei capitoli. Il primo capitolo è dedicato alla presentazione del robot chirurgico da Vinci, delle problematiche connesse all’attuazione a cavi, delle soluzioni proposte ed alla descrizione del giunto. Il secondo contiene cenni di fluidica ed una panoramica riguardo il circuito idraulico e le specifiche a cui attenersi in fase di progetto. Seguono poi tre capitoli dedicati alla presentazione di ciscuna componente del circuito: pompa, valvola e cilindro idraulico. Il sesto capitolo infine, affronta le prove sperimentali effettuate sui prototipi realizzati al laboratorio CRIM della Scuola Superiore Sant’Anna, ed i risultati ottenuti

Measuring 3D-orthodontic actions to guide clinical treatments involving coil springs and miniscrews

The understanding of the phenomena at the base of tooth movement, due to orthodontic therapy, is an ambitious topic especially with regard to the â\u80\u9coptimal forcesâ\u80\u9d able to move teeth without causing irreversible tissue damages. To this aim, a measuring platform for detecting 3D orthodontic actions has been developed. It consists of customized load cells and dedicated acquisition electronics. The force sensors are able to detect, simultaneously and independently of each other, the six orthodontic components which a tooth is affected by. They have been calibrated and then applied on a clinical case that required NiTi closed coil springs and miniscrews for the treatment of upper post-extraction spaces closure. The tests have been conducted on teeth stumps belonging to a plaster cast of the patientâ\u80\u99s mouth. The load cells characteristics (sensor linearity and repeatability) have been analyzed (0.97 < R 2 < 1; 6.3*10 â\u88\u926 % < STD < 8.8 %) and, on the basis of calibration data, the actions exerted on teeth have been determined. The biomechanical behavior of the frontal group and clinical interpretation of the results are discussed

Cardioscopically-guided beating heart surgery: paravalvular leak repair

Purpose: There remains a paucity of direct visualization techniques for beating-heart intracardiac procedures. To address this need, we evaluated a novel cardioscope in the context of aortic paravalvular leaks (PVLs) localization and closure.Description: A porcine aortic PVL model was created using a custom-made bioprosthetic valve, and PVL presence was verified by epicardial echocardiography. Transapical delivery of occlusion devices guided solely by cardioscopy was attempted 13 times in a total of three pigs. Device retrieval after release was attempted six times. Echocardiography, morphologic evaluation, and delivery time were used to assess results.Evaluation: Cardioscopic imaging enabled localization of PVLs via visualization of regurgitant jet flow in a paravalvular channel at the base of the prosthetic aortic valve. Occluders were successfully placed in 11 of 13 attempts (84.6%), taking on average 3:03 ± 1:34 min. Devices were cardioscopically removed successfully in three of six attempts (50%), taking 3:41 ± 1:46 min. No damage to the ventricle or annulus was observed at necropsy.Conclusions: Cardioscopy can facilitate intracardiac interventions by providing direct visualization of anatomic structures inside the blood-filled, beating-heart model