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Sensors (Basel, Switzerland) Feb 2013A hand biometric authentication method based on measurements of the user's hand geometry and vascular pattern is proposed. To acquire the hand geometry, the thickness of...
A hand biometric authentication method based on measurements of the user's hand geometry and vascular pattern is proposed. To acquire the hand geometry, the thickness of the side view of the hand, the K-curvature with a hand-shaped chain code, the lengths and angles of the finger valleys, and the lengths and profiles of the fingers were used, and for the vascular pattern, the direction-based vascular-pattern extraction method was used, and thus, a new multimodal biometric approach is proposed. The proposed multimodal biometric system uses only one image to extract the feature points. This system can be configured for low-cost devices. Our multimodal biometric-approach hand-geometry (the side view of the hand and the back of hand) and vascular-pattern recognition method performs at the score level. The results of our study showed that the equal error rate of the proposed system was 0.06%.
Topics: Algorithms; Artificial Intelligence; Biometric Identification; Blood Vessels; Hand; Humans; Image Processing, Computer-Assisted
PubMed: 23449119
DOI: 10.3390/s130302895 -
Science Robotics May 2021Humans have long been fascinated by the opportunities afforded through augmentation. This vision not only depends on technological innovations but also critically relies...
Humans have long been fascinated by the opportunities afforded through augmentation. This vision not only depends on technological innovations but also critically relies on our brain's ability to learn, adapt, and interface with augmentation devices. Here, we investigated whether successful motor augmentation with an extra robotic thumb can be achieved and what its implications are on the neural representation and function of the biological hand. Able-bodied participants were trained to use an extra robotic thumb (called the Third Thumb) over 5 days, including both lab-based and unstructured daily use. We challenged participants to complete normally bimanual tasks using only the augmented hand and examined their ability to develop hand-robot interactions. Participants were tested on a variety of behavioral and brain imaging tests, designed to interrogate the augmented hand's representation before and after the training. Training improved Third Thumb motor control, dexterity, and hand-robot coordination, even when cognitive load was increased or when vision was occluded. It also resulted in increased sense of embodiment over the Third Thumb. Consequently, augmentation influenced key aspects of hand representation and motor control. Third Thumb usage weakened natural kinematic synergies of the biological hand. Furthermore, brain decoding revealed a mild collapse of the augmented hand's motor representation after training, even while the Third Thumb was not worn. Together, our findings demonstrate that motor augmentation can be readily achieved, with potential for flexible use, reduced cognitive reliance, and increased sense of embodiment. Yet, augmentation may incur changes to the biological hand representation. Such neurocognitive consequences are crucial for successful implementation of future augmentation technologies.
Topics: Adult; Biomechanical Phenomena; Computer Simulation; Equipment Design; Female; Hand; Haptic Technology; Humans; Male; Man-Machine Systems; Printing, Three-Dimensional; Psychomotor Performance; Robotics; Sensorimotor Cortex; Task Performance and Analysis; Thumb; Young Adult
PubMed: 34043536
DOI: 10.1126/scirobotics.abd7935 -
Hand (New York, N.Y.) Nov 2022Ganglion cysts are the most common soft tissue tumor of the hand and wrist, affecting pediatric and adult populations. Despite their frequency, there is no consensus... (Review)
Review
Ganglion cysts are the most common soft tissue tumor of the hand and wrist, affecting pediatric and adult populations. Despite their frequency, there is no consensus within the literature regarding the best management of pediatric wrist ganglia, and there are few recent publications examining this topic. We provide an up-to-date literature review examining the current issues and controversies in the management of pediatric wrist ganglia.
Topics: Adult; Humans; Child; Ganglion Cysts; Wrist; Hand; Wrist Joint; Soft Tissue Neoplasms
PubMed: 33174451
DOI: 10.1177/1558944720966716 -
Cleveland Clinic Journal of Medicine Jun 2020
Topics: Diagnosis, Differential; Fingers; Hand; Humans; Male; Medical Illustration; Middle Aged; Monckeberg Medial Calcific Sclerosis; Skin Ulcer
PubMed: 32605975
DOI: 10.3949/ccjm.87a.19085 -
Nature Communications Dec 2021Robotic hands perform several amazing functions similar to the human hands, thereby offering high flexibility in terms of the tasks performed. However, developing...
Robotic hands perform several amazing functions similar to the human hands, thereby offering high flexibility in terms of the tasks performed. However, developing integrated hands without additional actuation parts while maintaining important functions such as human-level dexterity and grasping force is challenging. The actuation parts make it difficult to integrate these hands into existing robotic arms, thus limiting their applicability. Based on a linkage-driven mechanism, an integrated linkage-driven dexterous anthropomorphic robotic hand called ILDA hand, which integrates all the components required for actuation and sensing and possesses high dexterity, is developed. It has the following features: 15-degree-of-freedom (20 joints), a fingertip force of 34N, compact size (maximum length: 218 mm) without additional parts, low weight of 1.1 kg, and tactile sensing capabilities. Actual manipulation tasks involving tools used in everyday life are performed with the hand mounted on a commercial robot arm.
Topics: Anthropometry; Biomechanical Phenomena; Equipment Design; Fingers; Hand; Hand Joints; Hand Strength; Humans; Range of Motion, Articular; Robotics; Touch
PubMed: 34907178
DOI: 10.1038/s41467-021-27261-0 -
Acta Bio-medica : Atenei Parmensis Dec 2022Various aspects of fingerprint resarch were extensively explored in the past. However, the correlation between fingerprint ridge density and hand dimensions has not yet...
BACKGROUND AND OBJECTIVE
Various aspects of fingerprint resarch were extensively explored in the past. However, the correlation between fingerprint ridge density and hand dimensions has not yet been documented. Therefore, the present study has investigated the relationship so that some conclusions regarding the association can be established.
METHODS
The study included 500 subjects (250 males and 250 females) between the ages of 18 to 25 years who belonged to the Rajput community of the Shimla and Solan districts of Himachal Pradesh state of North India. The sexual dimorphism among the ridge count was examined using student's t-test. The relationship of fingerprint ridge density with hand dimensions among both the sexes and pooled data was analyzed using Pearson's correlation coefficient.
RESULTS
All the fingers on both hands showed statistically significant sex differences. When all digits were considered together, the left little finger in males and right middle finger in females showed a weak but significant correlation with hand length while all the digits when considered in combination reported strong correlation hand length measurements. Similarly, right thumb showed significant correlation with hand breadth. All the ten digits showed highly significant correlation with hand breadth when pooled data was examined.
CONCLUSION
The ridge density correlates with the hand dimensions in the case of pooled data. This relationship can then be used to devise prediction equations for hand dimensions based on ridge density, or vice-versa for pooled data. The equations will also help in estimating hand dimensions based on ridge density and vice-versa.
Topics: Humans; Male; Female; Adolescent; Young Adult; Adult; Dermatoglyphics; Hand; Fingers; Sex Characteristics; Sexual Behavior
PubMed: 36533749
DOI: 10.23750/abm.v93i6.13548 -
NeuroImage May 2013Hand velocity and acceleration are coherent with magnetoencephalographic (MEG) signals recorded from the contralateral primary sensorimotor (SM1) cortex. To learn more...
Hand velocity and acceleration are coherent with magnetoencephalographic (MEG) signals recorded from the contralateral primary sensorimotor (SM1) cortex. To learn more of this interaction, we compared the coupling of MEG signals with four hand-action-related peripheral signals: acceleration, pressure, force, and electromyogram (EMG). Fifteen subjects performed self-paced repetitive hand-action tasks for 3.5min at a rate of about 3Hz. Either acceleration, pressure or force signal was acquired with MEG and EMG signals during (1) flexions-extensions of right-hand fingers, with thumb touching the other fingers (acceleration; free), (2) dynamic index-thumb pinches against an elastic rubber ball attached to a pressure sensor (pressure and acceleration; squeeze), and (3) brief fixed-finger-position index-thumb pinches against a rigid load cell (force; fixed-pinch). Significant coherence occurred between MEG and all the four peripheral measures at the fundamental frequency of the hand action (F0) and its first harmonic (F1). In all tasks, the cortical sources contributing to the cross-correlograms were located at the contralateral hand SM1 cortex, with average inter-source distance (mean±SEM) of 9.5±0.3mm. The coherence was stronger with respect to pressure (0.40±0.03 in squeeze) and force (0.38±0.04 in fixed-pinch) than acceleration (0.24±0.03 in free) and EMG (0.25±0.02 in free, and 0.29±0.04 in fixed-pinch). The results imply that the SM1 cortex is strongly coherent at F0 and F1 with hand-action-related pressure and force, in addition to the previously demonstrated EMG, velocity, and acceleration. All these measures, especially force and pressure, are potential tools for functional mapping of the SM1 cortex.
Topics: Acceleration; Adult; Biomechanical Phenomena; Electromyography; Female; Hand; Humans; Magnetoencephalography; Male; Muscle, Skeletal; Pressure; Somatosensory Cortex; Young Adult
PubMed: 23357073
DOI: 10.1016/j.neuroimage.2013.01.029 -
Hand Surgery & Rehabilitation Feb 2021
Topics: Hand; Humans
PubMed: 33049371
DOI: 10.1016/j.hansur.2020.08.009 -
Reumatologia ClinicaThis article reviews the underlying anatomy of trigger finger and thumb (fibrous digital pulleys, sesamoid bones), flexor tenosynovitis, de Quervain's syndrome,... (Review)
Review
This article reviews the underlying anatomy of trigger finger and thumb (fibrous digital pulleys, sesamoid bones), flexor tenosynovitis, de Quervain's syndrome, Dupuytren's contracture, some hand deformities in rheumatoid arthritis, the carpal tunnel syndrome and the ulnar nerve compression at Guyon's canal. Some important syndromes and structures have not been included but such are the nature of these seminars. Rather than being complete, we aim at creating a system in which clinical cases are used to highlight the pertinent anatomy and, in the most important part of the seminar, these pertinent items are demonstrated by cross examination of participants and teachers. Self learning is critical for generating interest and expanding knowledge of clinical anatomy. Just look at your own hand in various positions, move it, feel it, feel also your forearms while you move the fingers, do this repeatedly and inquisitively and after a few tries you will have developed not only a taste, but also a lifelong interest in clinical anatomy.
Topics: Diagnosis, Differential; Hand; Humans; Musculoskeletal Diseases; Physical Examination
PubMed: 23219083
DOI: 10.1016/j.reuma.2012.10.004 -
Journal of Anatomy Aug 2021Microscopic anatomical study of the hand requires difficult or destructive dissection techniques for each anatomical structure. Synchrotron phase-contrast imaging (sPCI)...
Microscopic anatomical study of the hand requires difficult or destructive dissection techniques for each anatomical structure. Synchrotron phase-contrast imaging (sPCI) allows us to study precisely, at a microscopic resolution and in a nondestructive approach, the soft tissues and bone structures within a single 3D image. Therefore, we aimed to assess the capacity of sPCI to study the arterial anatomy of the hand and digits in human cadavers for anatomical purposes. A non-injected hand from an embalmed body was imaged using sPCI at 21-µm pixel size. The vascularization and innervation of the hands were virtually reconstructed at 84-µm resolution, and the medial neurovascular bundle of the third digit at 21 µm. The thinner-most distal structures were observed and reported. The diameter and thickness of the vascular and neural structures were defined on 2D computed tomographic axial projections, and using a granulometry method coupled to the 3D reconstructions. The vascularization of the hand was visible from the radial and ulnar arteries to the distal digital transverse anastomoses. The thinnest structure observed was the anastomotic arterial network around the proper palmar digital nerve. The latter emerged from the proper palmar digital artery and vascularized the nerve around its whole length and circumference. The perineural arterioles individualizable at this resolution had a diameter of 66-309 µm. In conclusion, sPCI allows both the arterial and neural anatomy of the hand to be studied at the same time, as well as the anatomical interactions between both networks. It facilitates the study of structures that have different sizes, diameters, thickness, and histological origin with great precision, in a noninvasive way, and using a single technique.
Topics: Aged, 80 and over; Electron Microscope Tomography; Female; Hand; Humans; Synchrotrons
PubMed: 33686643
DOI: 10.1111/joa.13427