Human Phalanx Research Articles

A Multi-Curvature, Variable Stiffness Soft Gripper for Enhanced Grasping Operations

For soft grippers to be applied in atypical industrial environments, they must conform to an object’s exterior shape and momentarily change their stiffness. However, many of the existing grippers have limitations with respect to these functions: they grasp an object with only a single curvature and a fixed stiffness. Consequently, those constraints limit the stability of grasping and the applications. This paper introduces a new multicurvature, variable-stiffness soft gripper. Inspired by the human phalanx and combining the phalanx structure and particle jamming, this work guarantees the required grasping functions. Unlike the existing soft pneumatic grippers with one curvature and one stiffness, this work tries to divide the pressurized actuating region into three parts to generate multiple curvatures for a gripper finger, enabling the gripper to increase its degrees of freedom. Furthermore, to prevent stiffness loss at an unpressurized segment, this work combines divided actuation and the variable-stiffness capability, which guarantee successful grasping actions. In summary, this gripper generates multiple grasping curvatures with the proper stiffness, enhancing its dexterity. This work introduces the new soft gripper’s design, analytical modeling, and fabrication method and verifies the analytic model by comparing it with FEM simulations and experimental results.

Asymmetric shape of distal phalanx of human finger improves precision grasping

In morphology field, the functions of an asymmetric-shaped distal phalanx in human finger have only been inferred. In this study, we used an engineering approach to empirically examine the effects of the shape of distal phalanx on the ability of precision grasping. Hence, we developed artificial fingertips consisting of four parts, namely bones, nails, skin, and subcutaneous tissue, that substitute the actual human fingertips. Furthermore, we proposed a method to evaluate the grasping ability of artificial fingers. When a cylindrical object was grasped by an artificial fingertip, a pull-out experiment was conducted. Thus, the asymmetric type was found to be superior in terms of drawing force, holding time, and work of friction than the symmetric type. Our results clearly demonstrate that the asymmetric shape, particularly the mirror-reversed shape of the distal phalanx, improves the ability of precision grasping and suggests that the human distal phalanx is shaped favorably for object grasping.

Finite element analysis of the proximal phalanx of the thumb in Hominoidea during simulated stone tool use

Finite element analysis was applied to analyze six individuals from different primate species (Homo sapiens Linnaeus, 1758, Homo neanderthalensis King, 1864, Pan troglodytes Blumenbach, 1779, Gorilla gorilla Savage, 1847, Pongo pygmaeus Linnaeus, 1760 and Hylobates lar Linnaeus, 1771) to identify stress distribution patterns on the pollical proximal phalanx during simulated hammerstone use. We expected the stress to be better distributed in our species than in other hominids based on the idea that, unlike apes, the human hand is adapted to tool-related behaviors. Our results indicate that the human phalanx unevenly distributes stresses and is one of the most fragile of all, especially when a small hammerstone is simulated. Tool orientation relative to the phalanx did not have a substantial effect on average stress or distribution. We conclude that great apes can resist loads exerted during this activity more efficiently than humans and that there were probably other evolutionary factors acting on this bone in our species.

Finite element analysis of the proximal phalanx of the thumb in Hominoidea during simulated stone tool use

Finite element analysis was applied to analyze six individuals from different primate species (Homo sapiens Linnaeus, 1758, Homo neanderthalensis King, 1864, Pan troglodytes Blumenbach, 1779, Gorilla gorilla Savage, 1847, Pongo pygmaeus Linnaeus, 1760 and Hylobates lar Linnaeus, 1771) to identify stress distribution patterns on the pollical proximal phalanx during simulated hammerstone use. We expected the stress to be better distributed in our species than in other hominids based on the idea that, unlike apes, the human hand is adapted to tool-related behaviors. Our results indicate that the human phalanx unevenly distributes stresses and is one of the most fragile of all, especially when a small hammerstone is simulated. Tool orientation relative to the phalanx did not have a substantial effect on average stress or distribution. We conclude that great apes can resist loads exerted during this activity more efficiently than humans and that there were probably other evolutionary factors acting on this bone in our species.

Optimal Design and Redundancy Resolution of a Novel Robotic Two-Fingered Exoskeleton

This article deals with the optimal design and redundancy resolution of a seven DOF robotic two-fingered hand exoskeleton intended for rehabilitation purposes. The exoskeleton is designed to track the human digit motion accurately. As the human digit joint cannot be modeled by single revolute joint due to instantaneously varying center of rotation, a 4-bar mechanism is employed to model each phalanx of a finger. Optimal 4-bar linkages are designed by minimizing the error between the Cartesian trajectories of the human phalanx and those of the coupler points in respective 4-bar mechanisms. It is demonstrated that the designed 4-bar based exoskeleton can track the human digit motion accurately. Performance analysis of the developed device has been carried out by resolving its kinematic redundancy during a fine object translation motion by instantaneously optimizing manipulability measure.

Influence of Periosteum Location on the Bone and Cartilage in Tissue-Engineered Phalanx

This study investigated the influence of periosteal tissue of different origins on the calcification at the diaphysis and chondrocyte maturation at the epiphysis in an engineered phalanx. We hypothesized that the periosteum from long bones would better provide donor cells for bone formation and signals for maturation of the joint cartilage. Periosteum was harvested from 4 locations (cranium, mandible, radius, and ilium) of calf bones. A human phalangeal bone-shaped, biodegradable, 3-dimensional scaffold hydroxyapatite-poly L-lactic-ɛ-caprolactone (HA-P[LA/CL]) was prepared using a human phalangeal bone-shaped template. A bioengineered human phalanx was fabricated by combining periosteal grafts with biodegradable copolymers. The joint cartilage region (chondrocyte/polyglycolic acid [PGA] composite) was subsequently sutured to the phalangeal bone region (periosteum/HA-P[LA/CL] composite) with absorbable sutures to make a human phalangeal bone model. These were then implanted in nude mice for maturation of the constructs. Macroscopic, radiographic, histological, and immune-histochemical evaluations were carried out to determine the relative influence of the periosteal graft source on bone and cartilage formation at 10 and 20 weeks after implantation. Calcification localized under the periosteum was noted in the cranium, radius, and ilium groups after 10 weeks, which markedly expanded at the modelled diaphysis after 20 weeks. The width in the minor axis direction tended to increase with time after grafting in the cranium group, whereas the longitudinal length increased in the radius and ilium groups. The joint cartilage thickness changed with time depending on the type of periosteum, and periosteum collected from the radius and ilium was associated with the greatest cartilage thickness in the joint cartilage maturation process. These results suggest that periosteum collected from radius of calves demonstrated superior bone formation and chondrocyte maturation in the engineered phalanx compared with other sources of periosteum. The osteogenic capacity depends on the periosteal source regardless of intramembranous or endochondral ossification. The appropriate periosteal choice is essential in the phalangeal bone and cartilage tissue engineering. The results are important for broadening tissue engineering possibilities for clinical application.

Tissue engineering a human phalanx.

A principal purpose of tissue engineering is the augmentation, repair or replacement of diseased or injured human tissue. This study was undertaken to determine whether human biopsies as a cell source could be utilized for successful engineering of human phalanges consisting of both bone and cartilage. This paper reports the use of cadaveric human chondrocytes and periosteum as a model for the development of phalanx constructs. Two factors, osteogenic protein-1 [OP-1/bone morphogenetic protein-7 (BMP7)], alone or combined with insulin-like growth factor (IGF-1), were examined for their potential enhancement of chondrocytes and their secreted extracellular matrices. Design of the study included culture of chondrocytes and periosteum on biodegradable polyglycolic acid (PGA) and poly-l-lactic acid (PLLA)-poly-ε-caprolactone (PCL) scaffolds and subsequent implantation in athymic nu/nu (nude) mice for 5, 20, 40 and 60weeks. Engineered constructs retrieved from mice were characterized with regard to genotype and phenotype as a function of developmental (implantation) time. Assessments included gross observation, X-ray radiography or microcomputed tomography, histology and gene expression. The resulting data showed that human cell-scaffold constructs could be successfully developed over 60weeks, despite variability in donor age. Cartilage formation of the distal phalanx models enhanced with both OP-1 and IGF-1 yielded more cells and extracellular matrix (collagen and proteoglycans) than control chondrocytes without added factors. Summary data demonstrated that human distal phalanx models utilizing cadaveric chondrocytes and periosteum were successfully fabricated and OP-1 and OP-1/IGF-1 accelerated construct development and mineralization. The results suggest that similar engineering and transplantation of human autologous tissues in patients are clinically feasible. Copyright © 2016 John Wiley & Sons, Ltd.

The Relationship between Strain Energy Release Rate with Crack-to-Width Ratio of Human Phalanx Bone

Bone fracture can occur in all parts of human skeletal cortical bone including phalanx bone of finger bone. Sometime, it leaves permanent damage and a long period of recovery. This situation can be prevented if we understand the mechanics and the process of the bone fracture. This study aims is to evaluate stress shielding induced by crack interaction using a simple model on Linear Elastic Fracture Mechanics (LEFM). Numerical simulation had been carried out in this study to understand the stress shielding induced by crack interaction. The results revealed that the interaction of two cracks is directly proportional to the stress intensity factor (SIF) magnitude at crack tips. Finally, as the crack-to-width ratio increase and the strain energy release rate also increased.

A Tissue‐Engineered Model of A Tendon‐to‐Bone Enthesis

The tendon-to-bone enthesis has a four-zone gradation of connective tissue that includes tendon followed by uncalcified cartilage, calcified cartilage, and bone. The loss of the tendon-to-bone attachment is a common and difficult problem in orthopedic injuries of the hand, elbow, shoulder, knee, heel and foot. These injuries may be treated surgically by repair, reconstruction or grafting methods, processes that may be beneficial to the patient but may also lead to complications such as adhesion formation, tenolysis, persistent tears and sub-optimal function. This study develops a tissue-engineering approach to generate a functional tendon-to-bone insertion site (an 'enthesis'), utilizing a phalanx model well characterized previously. This complete tissue-engineering process included fabrication of tendon-to-bone constructs, culture of constructs for 1-2 weeks, implantation of constructs in nude mice serving as bioreactors in vivo, construct harvest from mice, and retrieved construct immunohistological and biomechanical assessments. Preliminary data from a recently harvested 20-week construct demonstrated that the fabricated cell-seeded enthesis (II-IV, Fig. A) was viable and possessed stiffness three times greater than its non-seeded aspect (I, Fig. A). Subsequent studies will compare morphology, immunohistochemical markers, and additional biomechanical properties of fabricated entheses to the normal tendon-to-bone attachment of cadaveric or non-cadaveric adult surgical specimens of the human phalanx. Methods developed here could be applied in a broad translational sense for treatment and repair of isolated tendon injuries such as tears of the flexor tendon, Achilles tendon, and rotator cuff.

Numerical Simulation of Stress Shielding Induced by Crack Interaction in Human Phalanx Bone

Bone fracture is an injury not uncommon to everyday life. Most of the time, it leaves permanent damage and a long period of recovery. This situation can be prevented if we understand the mechanics and the process of the bone fracture. This study aim is to evaluate stress shielding induced by crack interaction using a simple model based on Linear Elastic Fracture Mechanics (LEFM). This simulation based on the determination of the Stress Intensity Factor (SIF) and the changes of stress shielding in different crack interval towards the human phalanx bone. Numerical simulation had been carried out in this project to understand the stress shielding induced by crack interaction. The results revealed that the interaction of two cracks is directly proportional to the SIF magnitude and interaction factor at the crack tips. The parallel cracks have experienced increasing shielding effect as the crack interval increase. The crack interaction limit (CIL) and crack unification limit (CUL) also had been accomplished for every range of crack interval in this project. Several improvements will be conducted for future development of this study, including various stresses loading subjected to the model, porous element added in the model, different planes of the model and use various methods in calculating the stress intensity factor (SIF).

Experimental study of vascularized to three dimensional printing of bionic human phalanx scaffold

Objective Explore based on microscopic-CT and three-dimensional printing produce bionic human phalanx scaffold composite adipose-derived stem cells (ADSCs) and recombinant human bone morphogenetic protein 2 (rhBMP-2) of blood vessels in the body,for the clinical treatment of phalangeal defects provide a theoretical basis Methods Take the 3rd generation ADSCs of the rabbits composite rhBMP-2,inoculated with Bionic phalanx bracket mixed culture after 10 days (experimental group) and simply Bionic phalanx bracket (control group) to wrapped in 12 adult beagle dogs lower back on both sides of the pedicle deep fascia,Use self-control,different times gross and histologic staining neovascularization Results The results shows two of the scaffolds in intrafascial both vascular capabilities.The amount of vessels and the expression of ⅧRAg in experimental groups were stronger than those in control groups at 2,4,8,and 16 weeks,the difference was statistically significant (P＜0.05).Conclusion The bionic human phalanx scaffold transplant in body with vascular capacity,composite ADSCs-rhBMP-2 can contribute to the degree of vascalarization. Key words: Bionic; Three dimensional printing; Adipose stem cells; Recombinant human bone morphogenetic protein-2; Vascularization

CV-0, an early Pleistocene human phalanx from Cueva Victoria (Cartagena, Spain)

CV-0, an early Pleistocene human phalanx from Cueva Victoria (Cartagena, Spain)

Reply to Gibert et al. (2008) on the supposed human phalanx from Cueva Victoria (Cartagena, Spain)

Reply to Gibert et al. (2008) on the supposed human phalanx from Cueva Victoria (Cartagena, Spain)

Tissue Engineering of a Small Hand Phalanx with a Porously Casted Polylactic Acid–Polyglycolic Acid Copolymer

In this study, we evaluate a porous polylactic acid-polyglycolic acid (PLGA) polymer in tissue engineering a small hand phalanx. The PLGA polymer was processed with a unique solvent cast/salt-leaching method in the shape of a little finger distal phalanx. An 85% polylactic acid (PLA)/15% polyglycolic acid (PGA) copolymer was determined to be the most favorable mixture for creating a small digital phalanx in precise shape and size. The pore sizes averaged 250-425 microm. Bovine periosteum was wrapped around each phalangeal polymer. Chondrocytes were injected into the articular end. Six constructs were surgically placed into a dorsal subcutaneous pocket of an ethylic mouse. After 8 (n=2) or 16 (n = 4) weeks, all implants demonstrated growth of bone and cartilage in the shape and size of a small hand phalanx, which was maintained throughout the study period. Histologic evaluation showed a homogeneous presence of bone and cartilage, with progressive tissue differentiation and matrix production from 8 to 16 weeks. The tissue-engineered bone formed through an endochondral ossification process. Articular cartilage was maintained where the chondrocytes were placed. These findings suggest that the porous PLGA polymer is an effective synthetic biodegradable device to support and guide tissue growth of bone and articular cartilage in the shape of a human phalanx.

Characterization of the Cellular Origin of a Tissue-Engineered Human Phalanx Model by<I> in Situ</I> Hybridization

Characterization of the Cellular Origin of a Tissue-Engineered Human Phalanx Model by<I> in Situ</I> Hybridization

Development of Cartilage and Bone During Formation of Phalanges by Tissue Engineering

Abstract Treatment of human congenital malformations and for loss of tissue or organ function is a serious clinical concern, frequently supported by harvesting autogenous tissue for reconstructive surgery. This paper summarizes an alternate approach through novel tissue engineering methods and describes cell-polymer composites that could be fundamental in developing advances for digit and joint replacement. The work utilizes cells from different sources transplanted on biodegradable polymer matrices to form structures with defined shape, morphological features and composition resembling those of human phalanges and intact joints. Polyglycolic acids (PGA) fibers (Albany International, Mansfield, MA) 15 μm in diameter were used as a mesh support for cell attachment and matrix formation. For cartilage and tendon cells, PGA alone served as a flat surface without specific shape. For bone cells, PGA was copolymerized with poly-L-lactic acid (PLLA) (Polysciences, Warrington, PA) and shaped after a human phalanx molded from cadaveric distal and middle phalangeal bones. Polymers were sterilized with ethylene oxide before use.

Comparative Morphometric Study of a Human Phalanx from the Lower Pleistocene Site at Cueva Victoria (Murcia, Spain), by means of Fourier Analysis, Shape Coordinates of Landmarks, Principal and Relative Warps

The presence of Homoin Europe longer than a million years ago is often discussed. The finding of a Lower Pleistocene phalanx from the karstic site of Cueva Victoria in Murcia (Spain) can contribute important information about this theme if the Homoidentification is confirmed. We have used an array of morphometric analyses to study this phalanx, and to compare it with human, gorilla and cercopithecid phalanges. The morphometric variates included conventional distance and surface area measurements estimated from radiographs of the phalanges, harmonic amplitudes from Fourier series fitted to their contours, and shape coordinates of landmarks. Discriminant analysis was used to compare the groups, and principal and relative warp analyses used to investigate the relative position of landmarks. Results obtained with all morphometric methods consistently indicated a human affinity for the fossil, and thus constitute further evidence of the presence of Homosp. in the southern Iberian Peninsula during the Lower Pleistocene.

A human phalanx from the lower palaeolithic site of cueva victoria (murcia, Spain)

The morphological, metrical, and discriminant function analysis of a phalanx from the Lower Pleistocene site of Cueva Victoria suggests that it differs significantly from carnivores and non-human primate groups, and closely resembles theHomo group studied. The phalanx has been classified as a IInd. phalanx of the 5th. finger of the right hand.

Oestrogen binding proteins in bone cell cytosol

Attempts were made to demonstrate the presence of specific oestrogen binding proteins ("receptors") in bone cells. High speed cytosol preparations of bone were incubated with several concentrations of radioactive oestradiol alone and with radioactive oestradiol in the presence of a specific antioestrogen, Nafoxidine. Separation of bound and free oestradiol was carried out by dextran coated charcoal treatment and by sucrose gradient ultracentrifugation. Several types of bones likely to be oestrogen-sensitive were investigated: human femoral heads, human phalanx, rat and rabbit calvaria, humeri and femora of female rats. In all experiments we were unable to demonstrate the presence of specific oestrogen receptors in bone cell cytosol indicating that the direct effect of oestrogens on bone, if present, is not mediated by specific oestrogen receptors.

癩菌BCGおよびヒトの指骨との免疫交叉性

癩菌BCGおよびヒトの指骨との免疫交叉性