The human hand is a complex system, with a large number of degrees of freedom (DoFs), sensors embedded in its structure, actuators and tendons, and a complex hierarchical control. Despite this complexity, the efforts required to the user to carry out the different movements is quite small (albeit after an appropriate and lengthy training). On the contray, prosthetic hands are just a pale replication of the natural hand, with significantly reduced grasping capabilities and no sensory information delivered back to the user. Several attempts have been carried out to develop multifunctional prosthetic devices controlled by electromyographic (EMG) signals (myoelectric hands), harness (kinematic hands), dimensional changes in residual muscles, and so forth, but none ofthese methods permits the "natural" control of more than two DoFs. This article presents a review of the traditional methods used to control artificial hands by means of EMG signal, in both the clinical and research contexts, and introduces what could be the future developments in the control strategy of these devices.

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The authors are developing devices for semi-autonomous or autonomous locomotion in the gastrointestinal (GI) tract. In this paper, they illustrate the systematic approach to the problem of "effective" locomotion in the GI tract and the critical analysis of "inchworm" locomotion devices, based on extensor and clamper mechanisms. The fundamentals of locomotion and the practical problems encountered during the development and the testing (in vitro and in vivo) of these devices are discussed. A mini device capable of propelling itself in the colon and suitable to perform, at least, rectum-sigmoidoscopy (the tract where approximately 60% of all colon cancers are found) is presented. This paper introduces preliminary, but useful, concepts for understanding, modeling and improving the performance of virtually any existing and novel devices for endoscopy of the GI tract.

This paper presents recent results on the development and control of a microgripper based on flexure joints, fabricated by LIGA and instrumented with semiconductor strain-gauge force sensors. The microgripper is the end-effector of a workstation developed to grasp and manipulate tiny objects such as the components of a typical biomedical microdevice. The development of the force control in the microgripper is of fundamental importance in order to achieve the dexterity and sensing capabilities required to perform assembly tasks for biomedical microdevices. As a step towards the definition of the force control strategy, system identification techniques have been used to model the microgripper. Results indicate that a proportional integral (PI) controller could be used to assure, at the same time, closed-loop stability of the system, and a bandwidth suitable for the intended applications. The force control is based on strain-gauge sensors which have been integrated in the microgripper and experimentally characterized. Sensor response in the idling condition and during grasp showed that they can provide useful information for force control of the microgripper.

In this paper we analyse the main characteristics of some micro-devices which have been developed recently for biomedical applications. Among the many biomedical micro-systems proposed in the literature or already on the market, we have selected a few which, in our opinion, represent particularly well the technical problems to be solved, the research topics to be addressed and the opportunities offered by micro-system technology (MST) in the biomedical field. For this review we have identified four important areas of application of micro-systems in medicine and biology: (1) diagnostics; (2) drug delivery;(3) neural prosthetics and tissue engineering; and (4) minimally invasive surgery. We conclude that MST has the potential to play a major role in the development of new medical instrumentation and to have a considerable industrial impact in this field.

In this case series study, we aimed to evaluate the feasibility of a subacute rehabilitation program for mechanically ventilated patients with severe consequences of COVID-19 infection. Data were retrospectively collected from seven males (age 37–61 years) who were referred for inpatient rehabilitation following the stay in the ICU (14–22 days). On admission, six patients were still supported by mechanical ventilation. All patients were first placed in isolation in a special COVID unit for 6–22 days. Patients attended 11–24 treatment sessions for the duration of rehabilitation stay (13–27 days), including 6–20 sessions in the COVID unit. The treatment included pulmonary and physical rehabilitation. The initially nonventilated patient was discharged prematurely due to gallbladder problems, whereas all six mechanically ventilated patients were successfully weaned off before transfer to a COVID-free unit where they stayed for 7–19 days. At discharge, all patients increased limb muscle strength and thigh circumference, reduced activity-related dyspnea, regained functional independence and reported better quality of life. Rehabilitation plays a vital role in the recovery of seriously ill post-COVID-19 patients. Facilities should develop and implement plans for providing multidisciplinary rehabilitation treatments in various settings to recover functioning and prevent the development of long-term consequences of the COVID-19 disease.

The authors present a critical survey of some representative technologies which are candidates for the development of microactuators for microrobots. Since the field of 'microrobotics' is an entirely new one, some concepts and definitions are given first; in particular, a distinction between 'micromachines' and 'microrobots' is proposed. Then, a further classification is proposed between three different types of robots: the 'miniature' robot, the 'microrobot' and the 'nanorobot', and their expected performances and fields of applications are discussed. The need for developing dedicated miniature actuators and microactuators emerges clearly from this discussion, together with the main requirements for this class of 'new' actuators. Finally, some significant examples of implementation of microactuators are illustrated, and the main advantages and limitations of each technology are discussed.