Visual Functions of the Primate Superior Colliculus.

The superior colliculus (SC) is a subcortical brain structure that is relevant for sensation, cognition, and action. In nonhuman primates, a rich history of studies has provided unprecedented detail about this structure's role in controlling orienting behaviors; as a result, the primate SC has become primarily regarded as a motor control structure. However, as in other species, the primate SC is also a highly visual structure: A fraction of its inputs is retinal and complemented by inputs from visual cortical areas, including the primary visual cortex. Motivated by this, recent investigations are revealing the rich visual pattern analysis capabilities of the primate SC, placing this structure in an ideal position to guide orienting movements. The anatomical proximity of the primate SC to both early visual inputs and final motor control apparatuses, as well as its ascending feedback projections to the cortex, affirms an important role for this structure in active perception.

Toward higher-performance bionic limbs for wider clinical use.

Most prosthetic limbs can autonomously move with dexterity, yet they are not perceived by the user as belonging to their own body. Robotic limbs can convey information about the environment with higher precision than biological limbs, but their actual performance is substantially limited by current technologies for the interfacing of the robotic devices with the body and for transferring motor and sensory information bidirectionally between the prosthesis and the user. In this Perspective, we argue that direct skeletal attachment of bionic devices via osseointegration, the amplification of neural signals by targeted muscle innervation, improved prosthesis control via implanted muscle sensors and advanced algorithms, and the provision of sensory feedback by means of electrodes implanted in peripheral nerves, should all be leveraged towards the creation of a new generation of high-performance bionic limbs. These technologies have been clinically tested in humans, and alongside mechanical redesigns and adequate rehabilitation training should facilitate the wider clinical use of bionic limbs.

Laparoscopic Electromyography and Electrostimulation of the Gastrointestinal Tract Before Placement of Theranostic Devices.

NEED: Electrical stimulation (ES) is a promising therapy for multisegmental gastrointestinal (GI) motility disorders such as gastroparesis with slow-transit constipation or chronic intestinal pseudo-obstruction. Wireless communicating GI devices for smart sensing and ES-based motility modulation will soon be available. Before placement, a potential benefit for each GI segment must be intraoperatively assessed. TECHNICAL SOLUTION: A minimally invasive multisegmental electromyography (EMG) analysis with ES of the GI tract is required. PROOF OF CONCEPT: Two porcine experiments were performed with a laparoscopic setup. Multiple hook-needle electrodes were subserosally applied in the stomach, duodenum, jejunum, ileum, and colon. EMG signals were acquired for computer-assisted motility analysis. Gastric ES, duodenal ES, jejunal ES, ileal ES, and colonic ES were applied. NEXT STEPS: Further technological and rapid regulatory solutions are desired to initialize a clinical trial of the next generation devices in the near future. CONCLUSION: We demonstrate a laparoscopic strategy with EMG analysis and ES of multiple GI segments. Thus, GI function may be evaluated before theranostic devices are placed. Extended GI resection or organ transplantation may be delayed or even avoided in affected patients.

A multi-Kalman filter-based approach for decoding arm kinematics from EMG recordings.

BACKGROUND: Remarkable work has been recently introduced to enhance the usage of Electromyography (EMG) signals in operating prosthetic arms. Despite the rapid advancements in this field, providing a reliable, naturalistic myoelectric prosthesis remains a significant challenge. Other challenges include the limited number of allowed movements, lack of simultaneous, continuous control and the high computational power that could be needed for accurate decoding. In this study, we propose an EMG-based multi-Kalman filter approach to decode arm kinematics; specifically, the elbow angle (θ), wrist joint horizontal (X) and vertical (Y) positions in a continuous and simultaneous manner. RESULTS: Ten subjects were examined from which we recorded arm kinematics and EMG signals of the biceps, triceps, lateral and anterior deltoid muscles corresponding to a randomized set of movements. The performance of the proposed decoder is assessed using the correlation coefficient (CC) and the normalized root-mean-square error (NRMSE) computed between the actual and the decoded kinematic. Results demonstrate that when training and testing the decoder using same-subject data, an average CC of 0.68 ± 0.1, 0.67 ± 0.12 and 0.64 ± 0.11, and average NRMSE of 0.21 ± 0.06, 0.18 ± 0.03 and 0.24 ± 0.07 were achieved for θ, X, and Y, respectively. When training the decoder using the data of one subject and decoding the data of other subjects, an average CC of 0.61 ± 0.19, 0.61 ± 0.16 and 0.48 ± 0.17, and an average NRMSE of 0.23 ± 0.07, 0.2 ± 0.05 and 0.38 ± 0.15 were achieved for θ, X, and Y, respectively. CONCLUSIONS: These results suggest the efficacy of the proposed approach and indicates the possibility of obtaining a subject-independent decoder.

Microwave Therapy for Cellulite: An Effective Non-Invasive Treatment.

BACKGROUND: Cellulite represents a common cosmetic problem that affects nearly all women. This study aimed to evaluate microwave therapy's effectiveness for cellulite treatment. METHODS: In this study, 26 women showing severe or moderate cellulite underwent four sessions of microwave therapy on the buttocks and posterior thighs. The following assessments were performed at baseline and the three-month follow-up after the last treatment: the Cellulite Severity Scale (CSS), Nürnberger-Müller classification scale, photographic evaluation, and buttocks/posterior thighs circumference measurements. A Likert scale questionnaire was used to assess patient satisfaction at the 3-month follow-up. RESULTS: The treatment positively affected the cellulite severity as confirmed by the Cellulite Severity Scale (CSS) and Nürnberger-Müller classification scale results. CSS showed a significant amelioration in cellulite severity between the initial assessment and the 3-month follow-up for the buttocks and posterior thighs, with total average scores that ranged from 10.7 ± 3.1 to 4.5 ± 1.8 (p < 0.01). The treatment also resulted in a remarkable improvement in comfort/satisfaction and a buttocks and posterior thighs circumference reduction. No serious adverse events were observed. CONCLUSIONS: Microwave therapy has proven to be a safe treatment for improving cellulite appearance and reducing body circumferences.

[Suicidality in schizophrenic psychosis: a current overview]. / Suizidalität bei schizophrenen Psychosen: eine aktuelle Übersicht.

BACKGROUND: Suicidality in schizophrenic psychosis is an important topic but stands in clinical everyday work behind the perception of suicide especially in affective disorders. Schizophrenic psychosis is recognized as an independent risk factor for suicide attempts and suicides, whereas it poses particular challenges to the clinical professional due to the frequent unpredictability, abruptness and brutality of the methods used. For this reason, the suicide of a psychotic patient often leaves the professional and non-professional environment disturbed. AIMS: An overview of the existing relevant literature on suicide in psychosis is given. Explanations on the psychodynamics, indications on pharmacotherapy and psychotherapy and considerations on prevention round off this article and provide an up to date overview of this topic for clinicians. MATERIAL AND METHODS: A search was carried out in PubMed and Google scholar using the terms "suicide", "suicidality", "schizophrenia", "suicide AND schizophrenia", "suicide AND psychosis", "suicidality AND schizophrenia", "suicidality AND psychosis", "suicidality AND psychosis AND prevention", "suicide AND psychosis AND prevention", "suicidality AND schizophrenia AND prevention", "suicide AND schizophrenia AND prevention". CONCLUSION: Clinicians must have knowledge of the specific risk factors for suicide in psychotic patients, the characteristics of suicide in terms of design and temporal connection with treatment. The exploration and assessment of suicidality is often more difficult in psychotic patients than in affective or personality disorder patients, as there are often impulsive suicide attempts that can be explained by (suddenly occurring) psychotic symptoms and are therefore difficult or even impossible to foresee.

Intramuscular Stimulation of Muscle Afferents Attains Prolonged Tremor Reduction in Essential Tremor Patients.

This study proposes and clinically tests intramuscular electrical stimulation below motor threshold to achieve prolonged reduction of wrist flexion/extension tremor in Essential Tremor (ET) patients. The developed system consisted of an intramuscular thin-film electrode structure that included both stimulation and electromyography (EMG) recording electrodes, and a control algorithm for the timing of intramuscular stimulation based on EMG (closed-loop stimulation). Data were recorded from nine ET patients with wrist flexion/extension tremor recruited from the Gregorio Marañón Hospital (Madrid, Spain). Patients participated in two experimental sessions comprising: 1) sensory stimulation of wrist flexors/extensors via thin-film multichannel intramuscular electrodes; and 2) surface stimulation of the nerves innervating the same target muscles. For each session, four of these patients underwent random 60-s trials of two stimulation strategies for each target muscle: 1) selective and adaptive timely stimulation (SATS) - based on EMG of the antagonist muscle; and 2) continuous stimulation (CON) of target muscles. Two patients underwent SATS stimulation trials alone while the other three underwent CON stimulation trials alone in each session. Kinematics of wrist, elbow, and shoulder, together with clinical scales, were used to assess tremor before, right after, and 24 h after each session. Intramuscular SATS achieved, on average, 32% acute (during stimulation) tremor reduction on each trial, while continuous stimulation augmented tremorgenic activity. Furthermore, tremor reduction was significantly higher using intramuscular than surface stimulation. Prolonged reduction of tremor amplitude (24 h after the experiment) was observed in four patients. These results showed acute and prolonged (24 h) tremor reduction using a minimally invasive neurostimulation technology based on SATS of primary sensory afferents of wrist muscles. This strategy might open the possibility of an alternative therapeutic approach for ET patients.

Simplified determination of commissural orientation in bicuspid aortic valves.

OBJECTIVES: In bicuspid aortic valves (BAV), commissural orientation (CO) varies between 180° and close to 120°. Postoperative CO has a strong effect on repair durability, and different repair approaches have been proposed according to CO; it is thus important for aortic repair. A precise, simple and reproducible determination by preoperative echocardiography would facilitate intraoperative decision-making. We compared 4 different methods of determination of CO in BAV. METHODS: Preoperative transoesophageal echocardiograms of 62 patients with BAV were analysed. CO was measured using either the coaptation centre or the geometric centre of the root. The geometric centre of the root was determined through approximation using a circle or an ellipse, or the midpoint of a line between the centre of the non-fused and the fused sinuses. RESULTS: The 3 different geometric methods led to almost identical results (interclass coefficient 0.98-0.99), with the line segment being the easiest to use. The use of the coaptation centre was associated with the underestimation of commissural angle of up to 30° compared to the geometric centre; the discrepancy was significant and most pronounced for asymmetric BAV (140-160°; P = 0.005). CONCLUSIONS: CO can reproducibly be determined using a line segment between the centre of the non-fused and fused sinuses. The use of the coaptation centre can lead to misleading results, in particular in asymmetric BAVs.

Robotic Setup Promises Consistent Effects of Multilocular Gastrointestinal Electrical Stimulation: First Results of a Porcine Study.

BACKGROUND: Electrical stimulation (ES) of several gastrointestinal (GI) segments is a promising therapeutic option for multilocular GI dysmotility, but conventional surgical access by laparotomy involves a high degree of tissue trauma. We evaluated a minimally invasive surgical approach using a robotic surgical system to perform electromyographic (EMG) recordings and ES of several porcine GI segments, comparing these data to an open surgical approach by laparotomy. MATERIALS AND METHODS: In 5 acute porcine experiments, we placed multiple electrodes on the stomach, duodenum, jejunum, ileum, and colon. Three experiments were performed with a median laparotomy and 2 others using a robotic platform. Multichannel EMGs were recorded, and ES was sequentially delivered with 4 ES parameters to the 5 target segments. We calculated pre- and poststimulatory spikes per minute (Spm) and performed a statistical Poisson analysis. RESULTS: Electrode placement was achieved in all cases without complications. Increased technical and implantation time were required to achieve the robotic electrode placement, but invasiveness was markedly reduced in comparison to the conventional approach. The highest calculated (c)Spm values were found in the poststimulatory period of the small bowel with both the conventional and robotic approaches. Six of the 20 Poisson test results in the open setup reached statistical significance and 12 were significant in the robotic experiments. CONCLUSIONS: The robotic setup was less invasive, revealed more consistent effects of multilocular ES in several GI segments, and is a promising option for future preclinical and clinical studies of GI motility disorders.

Translational development and pre-clinical evaluation of prototype gastrointestinal mock-up devices: only robotic placement of plastic?

Background: The aim of this study was to address the vision of wireless theranostic devices distributed along the gastrointestinal (GI) tract by defining design requirements, developing prototype mock-ups, and establishing a minimally invasive surgical approach for the implantation process.Methods: Questionnaires for contextual analysis and use case scenarios addressing the technical issues of an implantable GI device, a possible scenario for implantation, preparation and calibration of a device, and therapeutic usage by professionals and patients were completed and discussed by an interdisciplinary team of surgeons, engineers, and product designers. Two acute porcine experiments were conducted with a robotic surgical system under general anaesthesia.Results: A variety of requirements for the design and implantation of implantable devices for modulating GI motility were defined. Five prototype implant mock-ups were three-dimensional (3D)-printed from black polymer material (width 22.32 mm, height 7.66 mm) and successfully implanted on the stomach, duodenum, jejunum, ileum, and colon using the robotic surgical system, without any complications.Conclusions: Our study shows the development and successful pre-clinical evaluation of a reliable device design with a minimally invasive implantation approach. Several stages of device development, including pre-clinical tests, characterisation of clinical requirements, regulatory affairs, and marketing issues should be managed side by side.

Restoring Tactile sensations via neural interfaces for real-time force-and-slippage closed-loop control of bionic hands.

Despite previous studies on the restoration of tactile sensation on the fingers and the hand, there are no examples of use of the routed sensory information to finely control the prosthesis hand in complex grasp and manipulation tasks. Here it is shown that force and slippage sensations can be elicited in an amputee subject by means of biologically-inspired slippage detection and encoding algorithms, supported by a stick-slip model of the performed grasp. A combination of cuff and intraneural electrodes was implanted for eleven weeks in a young woman with hand amputation, and was shown to provide close-to-natural force and slippage sensations, paramount for significantly improving the subject's manipulative skills with the prosthesis. Evidence is provided about the improvement of the subject's grasping and manipulation capabilities over time, thanks to neural feedback. The elicited tactile sensations enabled the successful fulfillment of fine grasp and manipulation tasks with increasing complexity. Grasp performance was quantitatively assessed by means of instrumented objects and a purposely developed metrics. Closed-loop control capabilities enabled by the neural feedback were compared to those achieved without feedback. Further, the work investigates whether the described amelioration of motor performance in dexterous tasks had as central neurophysiological correlates changes in motor cortex plasticity and whether such changes were of purely motor origin, or else the effect of a strong and persistent drive of the sensory feedback.

Cusp Nadir Relocation by Root Remodeling in Unicuspid Aortic Valve Repair.

We describe a root remodeling technique for the unicuspid and unicommissural aortic valve with a moderately hypoplastic anterior commissure. This technique achieves symmetric bicuspidization without patch insertion to cusps. Partial cusp fusion of the anterior commissure is divided, and two symmetric tongues of a Dacron graft are sutured to each center of cusp insertion lines. The cusp nadirs are relocated posteriorly, and the bicuspidized valve has two sufficiently high commissures from a new angulated virtual basal ring. To optimize valve configuration, annuloplasty and prolapse correction according to effective height concept are added. This technique is a promising option in select patients.

The Foveal Visual Representation of the Primate Superior Colliculus.

A defining feature of the primate visual system is its foveated nature. Processing of foveal retinal input is important not only for high-quality visual scene analysis but also for ensuring precise, albeit tiny, gaze shifts during high-acuity visual tasks. The representations of foveal retinal input in the primate lateral geniculate nucleus and early visual cortices have been characterized. However, how such representations translate into precise eye movements remains unclear. Here, we document functional and structural properties of the foveal visual representation of the midbrain superior colliculus. We show that the superior colliculus, classically associated with extra-foveal spatial representations needed for gaze shifts, is highly sensitive to visual input impinging on the fovea. The superior colliculus also represents such input in an orderly and very specific manner, and it magnifies the representation of foveal images in neural tissue as much as the primary visual cortex does. The primate superior colliculus contains a high-fidelity visual representation, with large foveal magnification, perfectly suited for active visuomotor control and perception.

Five-fold Gastrointestinal Electrical Stimulation With Electromyography-based Activity Analysis: Towards Multilocular Theranostic Intestinal Implants.

BACKGROUND/AIMS: Motility disorders are common and may affect the entire gastrointestinal (GI) tract but current treatment is limited. Multilocular sensing of GI electrical activity and variable electrical stimulation (ES) is a promising option. The aim of our study is to investigate the effects of adjustable ES on poststimulatory spike activities in 5 GI segments. METHODS: Six acute porcine experiments were performed with direct ES by 4 ES parameter sets (30 seconds, 25 mA, 500 microseconds or 1000 microseconds, 30 Hz or 130 Hz) applied through subserosal electrodes in the stomach, duodenum, ileum, jejunum, and colon. Multi-channel electromyography of baseline and post-stimulatory GI electrical activity were recorded for 3 minutes with hook needle and hook-wire electrodes. Spike activities were algorithmically calculated, visualized in a heat map, and tested for significance by Poisson analysis. RESULTS: Post-stimulatory spike activities were markedly increased in the stomach (7 of 24 test results), duodenum (8 of 24), jejunum (23 of 24), ileum (18 of 24), and colon (5 of 24). ES parameter analysis revealed that 80.0% of the GI parts (all but duodenum) required a pulse width of 1000 microseconds, and 60.0% (all but jejunum and colon) required 130 Hz frequency for maximum spike activity. Five reaction patterns were distinguished, with 30.0% earlier responses (type I), 42.5% later or mixed type responses (type II, III, and X), and 27.5% non-significant responses (type 0). CONCLUSIONS: Multilocular ES with variable ES parameters is feasible and may significantly modulate GI electrical activity. Automated electromyography analysis revealed complex reaction patterns in the 5 examined GI segments.