Bent Fingers Research Articles

A soft pneumatic dexterous gripper with convertible grasping modes

This paper proposes a novel soft pneumatic dexterous gripper that consists of four soft fingers and a movable sucker. Compared with rigid dexterous hands and other soft grippers, the soft pneumatic dexterous gripper has four convertible grasping modes, which can grasp a wide range of objects due to the proposed conversion mechanism. Most parts of the dexterous gripper are 3D-printed with resin in order to make it lighter. The soft finger is made of silicone rubber with the pleated channel, making the grasping process more flexible and safer. The curvature performance of single finger is predicted through finite element analysis (FEA) before making a prototype. The simplified kinematic model and tip workspace of the gripper are obtained to reveal its grasping range. Then, a mathematical model of the soft bending finger is proposed in order to explain the relationship between input air pressure and the finger bending angle. Finally, the single finger bending and the gripper grasping experiments results validate the accuracy of the model, consistency of finite element analysis, and rationality of the design.

MODERN FINDINGS CONCERNING DEVELOPMENT AND FORMATION OF HUMAN HAND BONES

If in anatomy of the foot the leading principle is connection of individual parts, strengthening of their ligaments, then in the hand each component tends to become free, each joint tries to get rid of its connections, and each link – to get an individual perfected form. The article offers a brief review of the basic mechanisms of development and formation of the hand bones. In the process of evolution of the three parts of the arm (shoulder, forearm and hand), its final (distal) part – the hand – is of a particular importance. It becomes not only the performer of the will, but also the creator, educator of the brain. The territory of the projection of the hand and especially the thumb in the anterior and posterior central convolutions of the cerebral cortex is almost as long as the rest of the body. The skeleton of the hand is formed by skeletal tissues, which include cartilage and bone tissue having the only source of development – the mesenchyme. The cartilaginous tissue develops from the mesenchyme. In the embryo in the period of 5-6 weeks, chondrogenic areas are formed in the mesenchyme. They are determined by the greater density of the location of mesenchymal cells, significant mitotic activity and the absence of blood vessels. The function of the hand consists of three elements. Stretched forward hand, open, with straight fingers serves as a shovel,; bent fingers - crochet, tongs; more difficult function – snatching. When it is executed, a person, depending on the purpose of the movement, on the nature of the object (size, weight, shape, texture) forms a new mechanism from the hand each time. In the core of various movements of the hand there are six types of grasping: ragged, interdigital, planar, pinching, cylindrical, and spherical. The processes of osteo- and chondrogenesis are in a certain dependence on carbohydrate and lipid metabolism, in particular on the complete and sequential synthesis of carbohydrate-protein complexes – glycosaminoglycans, proteoglycans, collagen and their interaction with each other. Disorders in these processes lead to bone problems and, consequently, to the formation of cartilage defects and bones. In most cases, there is a certain sequence of appearance of ossification centers: first, the center of ossification of the trapezoid bone, then the navicular bone, and the last on – the trapezoid. At the same time, by the end of this age period, the ossification of the cartilaginous models of the epiphyses of the metacarpal bones and phalanges of the finger ends, and the design of the bone structure of the epimetaphysis of the short tubular bones.

A Soft-Robotic Gripper With Enhanced Object Adaptation and Grasping Reliability

A novel soft-robotic gripper design is presented, with three soft bending fingers and one passively adaptive palm. Each soft finger comprises two ellipse-profiled pneumatic chambers. Combined with the adaptive palm and the surface patterned feature, the soft gripper could achieve 40-N grasping force in practice, 10 times the self-weight, at a very low actuation pressure below 100 kPa. With novel soft finger design, the gripper could pick up small objects, as well as conform to large convex-shape objects with reliable contact. The fabrication process was presented in detail, involving commercial-grade three-dimensional printing and molding of silicone rubber. The fabricated actuators and gripper were tested on a dedicated platform, showing the gripper could reliably grasp objects of various shapes and sizes, even with external disturbances.

Highly stretchable and sensitive strain sensors using nano-graphene coated natural rubber

ABSTRACTFlexible, stretchable and wearable sensors are needed for the human motion detection. Here, a highly stretchable and sensitive strain sensor is fabricated based on the coating of nano-graphene platelets on natural rubber by simple dry coating process. The gauge factors are adjustable in the ranges of 0.78–52.53 depended on the preparation conditions and strain state. The sensors showed a high stretchability up to 750% and high durability of 1500 stretching–releasing cycles. The stretchable strain sensors are capable of detecting a bending fingers and the pulse of radial artery on the wrist. In addition, a smart glove made form five independent strain sensors was created. The data of the glove finger motions are used to control an avatar robotic hand.

Self-powering/self-cleaning electronic-skin basing on PVDF/TiO2 nanofibers for actively detecting body motion and degrading organic pollutants

A flexible self-powering/self-cleaning electronic-skin (e-skin) for actively detecting body motion and degrading organic pollutants has been fabricated from PVDF/TiO2 nanofibers. PVDF/TiO2 nanofibers are synthesized by high voltage electrospinning method. The e-skin can be driven by external mechanical vibration, and actively output piezoelectric impulse. The outputting piezoelectric voltage can be significantly influenced by different applied deformation, acting as both the body-motion-detecting signal and the electricity power for driving the device. The e-skin can detect various body motions, such as pressing, stretching, bending finger and clenching fist. The e-skin also has distinct self-cleaning characteristic through piezo-photocatalytic coupling process. The photocatalytic activity of TiO2 and the piezoelectric effect of PVDF are coupled in a single physical/chemical process, which can efficiently degrade organic pollutants on the e-skin. For example, methylene blue (MB) can be completely degraded within 40min under UV/ultrasonic irradiation. The present results could provoke a possible new research direction for realizing self-powering multifunctional e-skin.

K+···Cπ and K+···F Non-Covalent Interactions in π-Functionalized Potassium Fluoroalkoxides

Secondary interactions stabilize coordinatively demanding complexes of s-block metals [...]

Dona Aúrea, and: The Midwives, and: Dona Terezinha’s Oriole, and: Dona Orínia’s Hyacinth Macaw

Dona Aúrea, and: The Midwives, and: Dona Terezinha’s Oriole, and: Dona Orínia’s Hyacinth Macaw Eleanor Stanford (bio) Dona Aúrea I was midwife to fear. Its crowning. Its bloody show. Midwife to sun opening the cervix of the valley, slipping through the narrow pass to Angêlica Falls. I was midwife to spirit and to form. To the smooth egg still warm from the chicken. Midwife to death, too. The wind astonishing the canyon. Shaking that overtakes a body in transition. There was no other. When they called me I came. [End Page 166] The Midwives Bahia, Brazil The secrets of philosophy are the secrets of the body. You think because we’re old and wear headscarves and lay our hands on pregnant bellies we don’t know how the baby got in there? You think we didn’t once, or many times, slink into the thicket at the edge of town with a man, or even by ourselves? The secrets of the body are deeper. You think we didn’t once or twice invite the delivery boy in for a quick fuck? Dona Terezinha’s Oriole The cage swings above cow pasture. Wind through the tree branches, and bars of light and dark shifting on the hard-trod ground. Even the beams of your own body are meant to open. You don’t believe me? Terezinha’s seen: ribs unhinge. Hips [End Page 167] pivot: the same frame that contains us sometimes lets us go. Are you surprised? But it’s the midwife’s job to bring suffering into the world as well as beauty. Sofrê, they call me. Do you think that these sweet syllables mean grief? She reaches her bent finger through the bars to touch my bright cupped flame. Dona Orínia’s Hyacinth Macaw Baxíos, Sergipe How tenderly she’d pinion me: my heart a small throb beneath her thumb. For years this went on: the Spanish came and went, bought up the coastline, paid in empty promises. Their fancy hotels ill- conceived, part-built, like the son she never stopped mourning, the boy born still half-fish. One can live an entire life in the shallows. The ocean murky-eyed like us; like us, sharp-tongued and flightless, spreading its gray wing. With firm and steady hands, she’d apply the styptic powder to stanch the blood. [End Page 168] Eleanor Stanford Eleanor Stanford is the author of two books of poetry, Bartram’s Garden and The Book of Sleep. Her poems and essays have appeared in Ploughshares, the Iowa Review, Kenyon Review, and other journals. She was a 2014–2016 Fulbright fellow to Brazil, where she researched and wrote about traditional midwifery. She lives in the Philadelphia area. Copyright © 2017 University of Nebraska Press

CHANGES IN PATTERNS OF SENSORIMOTOR EEG RHYTHMS DURING MOTOR IMAGERY

Aim - the determination of common and individual characteristics in patterns of sensorimotor rhythms of EEG during motor imagery in upper and lower limbs. Materials and methods. 20 right-handed students of Samara State Medical University at the age of 18-20 years took part in the investigation, signing informed consent. Monopolar EEG was recorded with the use of 128-channel EEG recording system (BP-010302 BrainАmpStandart 128) at rest and during the imagining of monovector movements in 4 limbs (bending fingers of the right hand, bending fingers of the left hand, dorsiflexion of the right foot, dorsiflexion of the left foot); and during the imagining of triple-vector movements in the dominant hand (fingers bending, elbow flexion, wrist rotation). The following programs and methods were used during the processing of EEG: MatLab, IBM SPSS Statistics 22, ICA (independent component analysis), CSP (Common Spatial Pattern), LORETA. Results. It was found out that alpha2- and beta2- EEG frequency bands are highly significant for the formation of contralateral activation focus during motor imagery in the 4 limbs. ERD / ERS of the EEG rhythms were more pronounced during imagining movements in the dominant limbs (right hand, right leg) than in non-dominant.We found individuality of responses of sensorimotor EEG rhythms in addition to the general trends of EEG changes during imagination of one-type movement in the 4 limbs. The significance of changes in the power of EEG sensorimotor rhythms for differentiating 3 degrees of freedom during motor imagery in one limb was not found. Conclusion. Event-related desynchronization/synchro-nization(ERD/ERS) of sensorimotor EEG rhythms related to motor imagery has individual characteristics and their classification will lead to the significant increase of the number of degrees of freedom in creation and implementation of BCI.

Extracting hand articulations from monocular depth images using curvature scale space descriptors

We propose a framework of hand articulation detection from a monocular depth image using curvature scale space (CSS) descriptors. We extract the hand contour from an input depth image, and obtain the fingertips and finger-valleys of the contour using the local extrema of a modified CSS map of the contour. Then we recover the undetected fingertips according to the local change of depths of points in the interior of the contour. Compared with traditional appearance-based approaches using either angle detectors or convex hull detectors, the modified CSS descriptor extracts the fingertips and finger-valleys more precisely since it is more robust to noisy or corrupted data; moreover, the local extrema of depths recover the fingertips of bending fingers well while traditional appearance-based approaches hardly work without matching models of hands. Experimental results show that our method captures the hand articulations more precisely compared with three state-of-the-art appearance-based approaches.

Yenidoğan Döneminde Tanı Alan ve Hiperpireksi ile Seyreden Freeman-Sheldon Sendromu

Freeman-Sheldon syndrome is a rare disorder, and its exact incidence is not unknown. The most important manifestation of this syndrome is typical “whistling-face “appearance. Patient with this disorder typically have multiple contractures in the hands and feet at birth (distal arthrogryposis tip 2A). These contractures lead to permanently bent fingers and toes, hand deformity in which all of the fingers are angled outward toward the fifth finger (ulnar deviation, also called “windmill vane hand”). We report a male newborn with Freeman- Sheldon syndrome and hyperpyrexia without anesthesia. No reason could be found to explain the high fever. The febrile episodes persisted all throughout the day and occurred in intervals and reached 40-41° C. The acute phase reactants in each episode of high fever were normal. There were no clinical or laboratory findings of infection during this hyperpyrexia. That case is the second Freeman- Sheldon syndrome without anestesia in the literature.

Bent fingers’ angle calculation using supervised ANN to control electro-mechanical robotic hand

The shape of human hand is such that it can perform many tedious tasks easily. It can reach narrow places and can perform difficult operations. It can bend its fingers at different angles to pick or hold different objects and apply force via fingers or palm area. It is very helpful in many difficult applications. However, there is risk of injury to the human hand, or even life in dangerous operations. It is not advisable to gamble of human body parts for applications like land mine removal. Hence, there is a need of a robotic hand which can perform the same operation as a human hand does in real time. This paper discusses a vision-based technique of controlling a robotic hand which has human hand like joints in fingers. The user has to show a gesture to the system with bare hand without any limitation on hand direction and the robotic hand would mimic that gesture. The positions of human hand fingers were calculated using supervised Artificial Neural Network. The preprocessing made the whole algorithm faster by cropping the region of interest from input image frame. The gesture was extracted from the input image and fingertips, centre of palm were detected. The animated simulation of robotic hand is done in Blender® software.

空気圧ゴム人工筋を用いた二関節駆動を有する握力増幅グローブ

In this paper, a grip amplified glove consists of pneumatic artificial rubber muscles (PARMs) which are covered with an exoskeleton structure is developed. A bi-rticular mechanism with a PARM that is suitable for bending finger is realized. The glove has totally 10 DOFs consist of four units. To achieve power-assist motion properly, a PI control, which is based on the pressure value from the balloon sensor, is applied. Synchronized actuation of the PARMs adds to the user's own movements provides power and support the grasping. As the balloon type sensors are used, electric circuits can be separated from the finger parts that have advantage in the use of hostile environment. To evaluate the validity of the glove, the skin surface electromyography (EMG) signals of muscles are measured during grasping. These results demonstrate that the eff ectiveness of the power amplified glove.

Pena-Shokeir syndrome type I – combination of polyhydramnios and pulmonary hypoplasia in fetal akinesia

We present the case of an 18-year-old woman with her second pregnancy, whose first pregnancy was complicated by polyhydramnios. At week 30, the dysmorph fetus died in utero and was delivered via cesarean section due to placental abruption, but the exact diagnosis was not recognized at that time. During the patient's second pregnancy, increasing polyhydramnios was detected from the 19th gestational week. Ultrasound signs of fetal malformation also appeared later: abnormal position of limbs, narrow chest, oedema around the skull, and absence of stomach content. At week 34, decompression amniocentesis became necessary. Chromosome analysis was also carried out and a normal karyotype was obtained. At 39th gestational week, amnioscopy proved meconium staining of the amniotic fluid, thus labour was induced. Following amniotomy, sustained fetal bradycardia commenced and an emergency caesarean section was performed. Despite complex resuscitation, the 3000 gram male newborn died 2.5 hours after delivery, due to respiratory failure. Autopsy and histopathologic examination revealed a large, oedematous head, micrognathia, macroglossia, laryngeal oedema, narrow chest with pulmonary hypoplasia, gracile limbs with muscle atrophy, gracile and bent fingers, and a short umbilical cord. Based on the medical history, the course of the disease and the phenotype of the newborn, Pena-Shokeir syndrome type I was diagnosed. In the second part of the article, we review the etiology, pathogenesis, prenatal diagnosis and differential diagnosis of this syndrome, as well as some aspects of genetic counseling in such cases. To our knowledge, this is the first reported case of Pena-Shokeir syndrome in Hungary.

Turning of the receptor-binding domains opens up the murine leukaemia virus Env for membrane fusion

The activity of the membrane fusion protein Env of Moloney mouse leukaemia virus is controlled by isomerization of the disulphide that couples its transmembrane (TM) and surface (SU) subunits. We have arrested Env activation at a stage prior to isomerization by alkylating the active thiol in SU and compared the structure of isomerization-arrested Env with that of native Env. Env trimers of respective form were isolated from solubilized particles by sedimentation and their structures were reconstructed from electron microscopic images of both vitrified and negatively stained samples. We found that the protomeric unit of both trimers formed three protrusions, a top, middle and a lower one. The atomic structure of the receptor-binding domain of SU fitted into the upper protrusion. This was formed similar to a bent finger. Significantly, in native Env the tips of the fingers were directed against each other enclosing a cavity below, whereas they had turned outward in isomerization-arrested Env transforming the cavity into an open well. This might subsequently guide the fusion peptides in extended TM subunits into the target membrane.

The Troubles with Pinkies

The Troubles with Pinkies

Musical tone control apparatus

First Page

Flagellar hook structures of Caulobacter and Salmonella and their relationship to filament structure

Native flagellar hooks from a polarly flagellated bacterium, Caulobacter crescentus, and polyhooks from a peritrichously flagellated bacterium, Salmonella typhimurium. have been studied by densitometry of electron micrographs of negatively stained specimens, followed by computerized Fourier analysis and three-dimensional reconstruction. The two structures are remarkably similar. In both cases, the subunits are arranged along a right-handed basic helix of 2.3 nm pitch with successive subunits separated by an azimuthal angle of 64 to 65 °, and there is a pronounced system of continuous 6-start grooves and ridges on the surface of the structures. The subunit of Salmonella ( M r 42,000, versus 70,000 for Caulobacter) is somewhat thinner and yields a smaller overall hook diameter. The “bent finger” subunit shape and orientation in both cases suggests that the hook could bend readily by a sliding motion in the 11-start direction at inner radii, with the 6-start groove preventing collision at outer radii. The basic helical pitch of the Salmonella hook structure, and the number of subunits per basic helical turn (5.56) makes it highly compatible with the Salmonella flagellar filament (2.6 nm pitch. 5.51 subunits per turn); so also does the elongated shape and tilt angle of the hook and flagellin subunits in the respective structures. The two structures may therefore conjoin directly in the intact flagellum, although participation of a minor protein is not ruled out by the data.

Panmielopatia costituzionale con malformazioni multiple (sindrome di fanconi)

SUMMARYThe Author describes two case of Fanconi's syndrome in a 5-year-old boy and in an 11-year-old girl respectively. A diagnosis was made in both of erythroleucothrombocytofenia and medullary aplasia, cutaneous, hyperpigmentation, some shortened and bent fingers, symptoms of haemorragic diathesis and of alterations in body development with radiological signs of intracranic hypertension, high levels of plasmatic proteins with increased globulins. In the boy scleroedema was also found. The tests for haemorragic diathesis hinted in this case, at the presence of anticoagulants in the blood.The statistical study of all the cases published in the literature and an appraisel of the results by the methods of Lenz and Hogben induces the admission that Fanconi's syndrome is a hereditary disease transmitted by a recessive character with multiple effects irregularly expressed.

Studies on the Constitution of Tuberculous Patients. Report I.

The author examined the pulmonary tuberculosis from the constitutional aspect.In this paper, 522 tuberculous patients were observed concerning the dysharmonic development of their bodies, complaints and past history from the viewpoint of the hypothalamo-pituitary-adrenal function.The results obtained are as follows:1. The dysharmonic development and variations of the body which are found more frequently in the tuberculous patients examined than normal healthy control at a statistically significant rate, are narrowed middle face, narrowed and close eye-brows, unbalanced angle of lips, narrowed scaphoid palate, irregular rows of teeth, genu varum and valgum, bending and separating toes, phimosis and dysharmony of secondary hairiness on the skin (head, axillary, pubic and body hair) etc. and also nervous temperament, hypotention positive Aschner's reaction, the pas t history related to the hypothalamo-pituitary-system.2. The dysharmonic variations of the body which are recognized more frequently in the cases of the abnormal-shaped sella than the normal-shaped at a statistically significant rate, are asymmetric face, narrowed middle face, deep set eyes, epicanthus, strabismus, saddle-nose, diminished development of nose, narrowed scaphoid palate, irregular rows of teeth, bending fingers, genu varum and valgum, bending and separating toes, deformities of fingers and toes, inguinal hernia, polymastia and dysharmony of secondary hairiness on the skin etc. and also hypotention, nervous temperament, the past history related to the hypothalamo-pituitary-system. Among the complaints, spasmoidic diathesis, migraine and thirst-feeling are recognized at high rate.3. It is recognized that the abnormal-shaped sella are frequently found in the serious cases and many normal-shaped are found in the mild cases. Moreover, when the course of pulmonary tuberculosis are taken into consideration with their shape of sellaprofile, those cases of which the sellaprofile are abnormal have generally acute course and chronic patients are distinctly found in the normal-shaped sellaprofile group.

A PEDIGREE OF CURVED FOREFINGERS*

MANY congenital anomalies of the hands have been reported, but little systematic study of normal hand characters appears to have been made. The purpose of this paper is to present the results of an investigation of curved fingers, a hand variation which has been diagnosed by radiologists as within the range of normal structure. Simply inherited non-pathological human traits are important not only as markers in linkage studies, but are of considerable value as a means of educating the public regarding heredity. The trait we are reporting is illustrated in Figures 9 to 12. Figure 10 shows the curvature of the forefinger which is characteristic of many persons in the families studied. In this figure digits other than the forefinger are also curved, but in Figure 9 only the forefingers show a distinct curvature. Since there seems to be a predominance of curved index fingers among the curved digits studied, the authors concentrated largely on the study of this particular digit. However, some general observations were made on the curvature of other fingers and these are also discussed. The curved forefingers of the pedigree in Figure 11 are characterized by a variable deviation to the ulnar side of the two distal phalanges of one or both index fingers (Figures 9 and 10). Clinodactyly is a technical term which has been used to describe a permanent lateral deviation of the phalanges. Although technically it would be correct to speak of curved forefingers, shown in Figure 10, as clinodactyly, nevertheless, insofar as usage is concerned it would appear that clinodactyly is a term which has been largely applied to those lateral deviations of the phalanges which are so great as to be recognized as pathological variations of the fingers. For example Utis illustrates clinodactyly in the brachydactylous hands of a mother and daughter. In these cases the inclination of the fingers is quite obvious. However, only the most critical observer would note the curvature of the forefingers illustrated in Figure 9. In fact some members of this family were not aware of the fact that there was any curvature of their fingers until it was brought to their attention by this investigation. Curvature of the forefingers within the range found in this study did not in any way impair the function of the affected digits. As pointed out above there seems to be little literature on a systematic study of curved forefingers. Whitney mentions that such a trait does seem to run in families, but does not indicate the mode of inheritance. It would seem logical to assume that the difference between a case of curved fingers such as discussed in this paper and typical clinodactyly is only one of degree. Clinodactyly has been studied by Barbosa Sueiro and Fontes. Dubreuil-Chamberdel, Mauclaire, Nowak, Tomesku, and Zurukzoglu. Many papers have been published on camptodactyly, a hereditary distortion of the finger resulting in a fixed flexion or, less common, in a fixed extension. It has been suggested that the term streblomicrodactyly be reserved for bent little finger as contrasted with camptodactyly which merely means bent finger and is applicable to any digit. Although in some pedigrees camptodactyly and streblomicrodactyly skip