Steering and control of miniaturized untethered soft magnetic grippers with haptic assistance.

Untethered miniature robotics have recently shown promising results in several scenarios at the microscale, such as targeted drug delivery, microassembly, and biopsy procedures. However, the vast majority of these small-scale robots have very limited manipulation capabilities, and none of the steering systems currently available enable humans to intuitively and effectively control dexterous miniaturized robots in a remote environment. In this paper, we present an innovative micro teleoperation system with haptic assistance for the intuitive steering and control of miniaturized self-folding soft magnetic grippers in 2-D space. The soft grippers can be wirelessly positioned using weak magnetic fields and opened/closed by changing their temperature. An image-guided algorithm tracks the position of the controlled miniaturized gripper in the remote environment. A haptic interface provides the human operator with compelling haptic sensations about the interaction between the gripper and the environment, as well as enables the operator to intuitively control the target position and grasping configuration of the gripper. Finally, magnetic and thermal control systems regulate the position and grasping configuration of the gripper. The viability of the proposed approach is demonstrated through two experiments involving 26 human subjects. Providing haptic stimuli elicited statistically significant improvements in the performance of the considered navigation and micromanipulation tasks. Note to Practitioners-The ability to accurately and intuitively control the motion of miniaturized grippers in remote environments can open new exciting possibilities in the fields of minimally-invasive surgery, micromanipulation, biopsy, and drug delivery. This paper presents a micro teleoperation system with haptic assistance through which a clinician can easily control the motion and open/close capability of miniaturized wireless soft grippers. It introduces the underlying autonomous magnetic and thermal control systems, their interconnection with the master haptic interface, and an extensive evaluation in two real-world scenarios: following of a predetermined trajectory, and pick-and-place of a microscopic object.

Cutaneous Force Feedback as a Sensory Subtraction Technique in Haptics.

A novel sensory substitution technique is presented. Kinesthetic and cutaneous force feedback are substituted by cutaneous feedback (CF) only, provided by two wearable devices able to apply forces to the index finger and the thumb, while holding a handle during a teleoperation task. The force pattern, fed back to the user while using the cutaneous devices, is similar, in terms of intensity and area of application, to the cutaneous force pattern applied to the finger pad while interacting with a haptic device providing both cutaneous and kinesthetic force feedback. The pattern generated using the cutaneous devices can be thought as a subtraction between the complete haptic feedback (HF) and the kinesthetic part of it. For this reason, we refer to this approach as sensory subtraction instead of sensory substitution. A needle insertion scenario is considered to validate the approach. The haptic device is connected to a virtual environment simulating a needle insertion task. Experiments show that the perception of inserting a needle using the cutaneous-only force feedback is nearly indistinguishable from the one felt by the user while using both cutaneous and kinesthetic feedback. As most of the sensory substitution approaches, the proposed sensory subtraction technique also has the advantage of not suffering from stability issues of teleoperation systems due, for instance, to communication delays. Moreover, experiments show that the sensory subtraction technique outperforms sensory substitution with more conventional visual feedback (VF).

Melatonin in psychiatric disorders: a review on the melatonin involvement in psychiatry.

In normal subjects, the secretion of melatonin, the pineal hormone that regulates the rhythm of many functions, exhibits a circadian pattern synchronized with the day-night cycle. An alteration of this secretory pattern has been found in various psychiatric disorders (seasonal affective disorder, bipolar disorder, unipolar depression, bulimia, anorexia, schizophrenia, panic disorder, obsessive compulsive disorder). At present, it is not known if such alterations have an etiological role or are secondary to the dysfunctions underlying the different disorders. In addition, we do not know if the involvement of melatonin in several disorders has the same significance in the pathophysiology of each disorder. An understanding of the role of the pineal hormone and of its alterations in psychiatric diseases could help to identify the biological mechanisms underlying such disorders.

Electroretinogram B-wave amplitude in panic disorder.

Abnormal light-related behaviors have been described for patients with panic disorder (PD). The present study was undertaken to investigate the retinal light response in PD using electroretinography (ERG). The authors conducted b-wave ERG measurements with a bright light (after dark adaptation) in 28 patients with PD and 28 control subjects. There were no significant differences in the mean b-wave amplitude between the two groups, but the retinal response to light in PD patients was generally lower than in healthy subjects. A large interindividual variability was found; also noted was a significant difference in the mean b-wave amplitude between the right and left eyes in the control group. The data indicate subtle variation of retinal photosensitivity in a subgroup of patients with PD. Because dopaminergic retinal activity affects b-ERG amplitude, the authors hypothesize that the dopaminergic system is involved in the response to light in PD patients.

Season of birth in panic disorder.

Several studies have investigated the seasonal distribution of the birth dates of patients with psychiatric diseases. Our purpose was to verify if there is a specific distribution (by month) of birth dates in subjects with panic disorder (PD). The birth dates of 843 outpatients with a diagnosis of PD were compared with those of 1,181 subjects with other mental diseases. The birth dates of psychiatric patients were compared to those of the general Tuscane and Italian populations. The monthly distribution of birth in patients with PD (with and without comorbidity) peaked in September to December, while no relevant deviation in birth rate was observed in other mental diseases. Our results suggest a pathogenic role of birth seasonality in the development of PD.

Season of birth in psychiatry. A review.

Numerous studies suggest that seasonal birth may play a pathogenic role in the development of mental disorders. A birth excess of 10% during winter and spring has been shown in schizophrenia. The few studies carried out on affective disorders revealed a significant increase of births in the first quarter of the year in bipolar disorders and major depressive disorder. Subjects with seasonal affective disorder show a peak of births in May. Data on personality, eating and 'neurotic' disorders are less consistent. At the moment there are no data in the literature about anxiety disorders.