The micromanipulation of micro objects is nowadays the focus of several investigations, specially in biomedical applications. Therefore, some manipulation tasks are required to be in aqueous environment and become more challenging because they depend upon observation and actuation methods that are compatible with MEMS Technology based micromanipulators. This paper describes how three grasping-releasing based tasks have been successfully applied to agarose micro beads whose average size is about 60 $\mathsf{\mu }$ m: (i) the extraction of a single micro bead from a water drop; (ii) the insertion of a single micro bead into the drop; (iii) the grasping of a single micro bead inside the drop. The success of the performed tasks rely on the use of a microgripper previously designed, fabricated, and tested.

Purpose The aim of this study is to evaluate the safety and efficacy of endoluminal loco-regional resection (ELRR) by transanal endoscopic microsurgery (TEM) after R1 endoscopic resection or local recurrence of early rectal cancer after operative endoscopy. Material and methods Twenty patients with early rectal cancer were enrolled, including patients with incomplete endoscopic resection, or complete endoscopic resection of a tumor with unfavorable prognostic factors (group A, ten patients), and local recurrence after endoscopic removal (group B, ten patients). At admission, histology after endoscopic polypectomy was: TisR1(4), T1R0G3(1), T1R1(5) in group A, and TisR0(8), T1R0(2) in group B. All patients underwent ELRR by TEM with nucleotide-guided mesorectal excision (NGME). Results Mean operative time was 150 minutes. Complications occurred in two patients (10%). Definitive histology was: moderate dysplasia(4), pT0N0(3), pTisN0(5), pT1N0(6), pT2N0(2). Mean number of lymph-nodes was 3.1. Mean follow-up was 79.5 months. All patients are alive and disease-free. Conclusions ELRR by TEM after R1 endoscopic resection of early rectal cancer or for local recurrence after operative endoscopy is safe and effective. It may be considered as a diagnostic procedure, as well as a curative treatment option, instead of a more invasive TME.

This work offers a new alternative tool for atherectomy operations, with the purpose of minimizing the risks for the patients and maximizing the number of clinical cases for which the system can be used, thanks to the possibility of scaling its size down to lumen reduced to a few tenths of mm. The development of this microsystem has presented a certain theoretical work during the kinematic synthesis and the design stages. In the first stage a new multi-loop mechanism with a Stephenson’s kinematic chain (KC) was found and then adopted as the so-called pseudo-rigid body mechanism (PRBM). Analytical modeling was necessary to verify the synthesis requirements. In the second stage, the joint replacement method was applied to the PRBM to obtain a corresponding and equivalent compliant mechanism with lumped compliance. The latter presents two loops and six elastic joints and so the evaluation of the microsystem mechanical advantage (MA) had to be calculated by taking into account the accumulation of elastic energy in the elastic joints. Hence, a new closed form expression of the microsystem MA was found with a method that presents some new aspects in the approach. The results obtained with Finite Element Analysis (FEA) were compared to those obtained with the analytical model. Finally, it is worth noting that a microsystem prototype can be fabricated by using MEMS Technology classical methods, while the microsystem packaging could be a further development for the present investigation.