Design and Analysis of Reconfigurable Origami-Based Vacuum Pneumatic Artificial Muscles for Versatile Robotic System.

In this study, a vacuum-based modular actuator system named reconfigurable origami-based vacuum pneumatic artificial muscles (ROV-PAMs) is presented. The system consists of six types of actuating modules and three types of fluidic supporting modules each embedded with magnet-based connectors so that the modules can be assembled to modify the system behavior. The module can be used in a myriad of ways, including extending their working range, creating complex geometries upon deformation, and cooperating to improve overall performance. A simple analytical model for the actuating modules is derived based on the law of conservation of energy, and the model is verified experimentally which shows that this intuitive model can provide a reasonable prediction of performance. A block sorting robot is built using three different types of actuating modules with multiple fluidic supporting modules, and the robot shows that it is possible to flexibly and easily assemble modules to build a robot capable of completing diverse tasks. The ROV-PAM module and its concept can be applied to realize robotic designs, which can be altered on-the-fly to adjust its functionality to meet the evolving requirements required for truly flexible automation.

Node-Wise Monotone Barrier Coupling Law for Formation Control.

We study a node-wise monotone barrier coupling law, motivated by the synaptic coupling of neural central pattern generators. It is illustrated that this coupling imitates the desirable properties of neural central pattern generators. In particular, the coupling law (1) allows us to assign multiple central patterns on the circle and (2) allows for rapid switching between different patterns via simple 'kicks'. In the end, we achieve full control by partitioning the state space by utilizing a barrier effect and assigning a unique steady-state behavior to each element of the resulting partition. We analyze the global behavior and study the viability of the design.

Analysis of the mechanism and clinical classification of thoracolumbar scoliosis using three-dimensional EOS and surface electromyography.

To analyze a thoracolumbar scoliosis group, we analyzed data from the acquired database by groups: the sEMG group (n = 16) and 3D-EOS group (n = 55). The asymmetric hyper/hypoactivation ratio of muscle and LLD (>3 mm) were measured in the sEMG group. In the 3D-EOS group, we recorded the values of parameters including LLD, pelvis rotation, and kyphosis/lordosis. In the sEMG study, sEMG examinations were conducted individually in patients with idiopathic scoliosis to analyze hyper/hypoactivation of the paraspinal muscle. In the three-dimensional EOS study, the Cobb angle, femoral height difference, and thoracic kyphosis and lumbar lordosis angles were measured using 2D images and 3D reconstructed images. Sixteen patients with thoracolumbar scoliosis were classified into asymmetric hyperactivation (A-Hyper) and asymmetric hypoactivation (A-Hypo) groups. The Cobb angle of the A-Hyper subtype was significantly higher than that of the A-Hypo subtype (22.41 versus 15.2, p = 0.023). Coronal deviation (p = 0.028) and the pelvis rotation angle (p = 0.001) were significantly higher in the LLD (+) subtype than in the LLD (-) subtype. When we classified patients cross-sectionally along with A-Hyper/Hypo and LLD (±), A-Hyper elevated the Cobb angle, and LLD (+) was significantly correlated with coronal deviation and pelvis rotation. In the 3D-EOS evaluation, the pelvic height difference (p = 0.043) and coronal deviation (p = 0.001) were significantly higher in the LLD (+) subtype than in the LLD (-) subtype. In conclusions, paraspinal muscular asymmetry and LLD can be strong factors in inducing or progressing thoracolumbar scoliosis.

Radius palmar plate removal without carpal tunnel release: Correlation between plate position and median nerve symptoms.

We aimed to report the clinical results of volar plate removal without carpal tunnel release in patients with late-onset median neuropathy and to evaluate the relationship between plate position and median nerve symptoms. Part I. Twelve consecutive patients with late-onset median neuropathy treated with volar plate removal without carpal tunnel release were enrolled for analysis. Pre- and post-operative Tinel sign, Phalen and Ten test, subjective rating of tingling sensation, Mayo wrist score and Disabilities of the Arm, Shoulder and Hand (DASH) score were collected. Part II. 232 consecutive patients underwent volar plating for distal radius fracture. The relationships between median nerve symptoms and volar plate prominence on the Soong classification, fracture classification, gender and age were investigated. All cases except one showed complete symptom resolution at final follow-up, with negative Tinel sign and Ten test score of 10/10. Tingling was rated 0 at final follow-up. Mean Mayo wrist and DASH scores improved to 86.7 and 23.1, respectively. The incidence of the median nerve symptoms in our cohort was 5.6%. Even though the odds ratio in Soong grade 2 was 4.0957 (95% CI, 0.93-16.9) compared to the combination of grades 0 and 1, no statistically significant relationship was found between the median nerve symptoms and volar plate prominence (p > 0.05). Plate removal without carpal tunnel release adequately relieved symptoms of late-onset median neuropathy after volar plating in patients with distal radius fracture. LEVEL OF EVIDENCE: IV; Therapeutic.

Armor-Based Stable Force Pneumatic Artificial Muscles for Steady Actuation Properties.

In this article, a novel actuator called armor-based stable force pneumatic artificial muscle (AS-PAM) is presented. AS-PAM has a sealed chamber made of polygonal parts and film, which helps the actuator to be lightweight (∼100 g) and achieve a large contraction ratio (>60%). It has an armor and a constraint to guide its motion, which keeps its force output [6.25 N/(cm2·bar)] stable over its operating range (<10% deviation). An analytical model is presented to predict and control the behavior of the actuator, and various experiments were conducted to show the validity of the model. Afterward, a gripper using the actuators is presented to illustrate how it can be used in real applications. With its characteristics, the actuator shows interesting behaviors that cannot be found in other soft pneumatic actuators, and it would allow AS-PAM to expand the range of applications in which soft robots cooperate with humans.

Sodium-Doped Titania Self-Rectifying Memristors for Crossbar Array Neuromorphic Architectures.

Memristors integrated into a crossbar-array architecture (CAA) are promising candidates for nonvolatile memory elements in artificial neural networks. However, the relatively low reliability of memristors coupled with crosstalk and sneak currents in CAAs have limited the realization of the full potential of this technology. Here, high-reliability Na-doped TiO2  memristors grown in situ by atomic layer deposition (ALD) are demonstrated, where reversible Na migration underlies the resistive-switching mechanism. By employing ALD growth with an aqueous NaOH reactant in deionized water, uniform implantation of Na dopants is achieved in the crystallized TiO2  thin films at 250 °C without post-annealing. The resulting Na-doped TiO2  memristors show electroforming-free and self-rectifying resistive-switching behavior, and they are ideally suited for selectorless CAAs. Effective addressing of selectorless nodes is demonstrated via electrical measurement of individual memristors in a 6 × 6 crossbar using a read current of less than 1 µA with negligible sneak current at or below the noise level of ≈100 pA. Finally, the long-term potentiation and depression synaptic behavior from these Na-doped TiO2  memristors achieves greater than 99.1% accuracy for image-recognition tasks using a convolutional neural network based on the selectorless of crossbar arrays.

Strategies of upper blepharoplasty in aging patients with involutional ptosis.

In many aging individuals, dermatochalasis and involutional ptosis appear together. Therefore, for functional and aesthetic purposes, ptosis correction and upper blepharoplasty are performed together. The aim of this article is to investigate factors that should be considered in order to achieve good results when simultaneously performing involutional ptosis correction and upper blepharoplasty in aging patients. Involutional ptosis is usually corrected through aponeurosis advancement in mild cases. In moderate or severe ptosis, the Muller muscle and aponeurosis are used together to correct ptosis. Using the two muscles together has the advantages of reducing lagophthalmos and increasing the predictability of outcomes after surgery. Broadly speaking, the surgical method used for involutional ptosis varies depending on the specific case, but unlike congenital ptosis, it is often not necessary to perform overcorrection. In particular, if there are problems such as severe dry-eye symptoms or risk of lagophthalmos, undercorrection should be considered. When performing ptosis correction, the surgeon should be careful not to overdo skin excision; instead, limited excision should be performed. After ptosis surgery, the brow may descend and the double fold may look too small. However, in order to make the double eyelids look larger, the surgeon should consider making the double eyelid design high rather than excising an excessive amount of skin. In some cases, to obtain more natural double eyelids and favorable results, it may be necessary to perform a sub-brow lift or forehead lift before or after involutional ptosis surgery.

Origami-Based Vacuum Pneumatic Artificial Muscles with Large Contraction Ratios.

A novel linear actuator called origami-based vacuum pneumatic artificial muscle (OV-PAM) is proposed in this study that can produce large forces (>400 N) with a contraction ratio >90% of the active length of the actuator. Moreover, some of the designs presented in this article can lift large loads with large contraction ratios at extremely low vacuum pressure (≈10 kPa). This actuator consists of a sealed origami film chamber connecting a polygonal top and bottom plate with evenly spaced transversal reinforcements that prevent the chamber from contracting laterally at certain points of the actuator under vacuum pressure. As vacuum pressure is applied, both a tension force in the walls and a vertical force on the bottom plate of the actuator generate a large contractile force, and the force on the bottom plate can produce a consistent force throughout the entire motion. A quasistatic analytical model was developed that can accurately predict the behavior of the actuator and that can be used for actuator design. OV-PAMs are lightweight, have large contractile forces throughout their entire motion and large contraction ratios. It can also produce large forces at low pressures with large cross-sectional areas. Their versatility could make them well suited for a wide range of applications. They could take us closer to a future where robots can cooperate with humans to shape a better future.

Optical properties of ultra-thin (< 30 nm) GaN layers on c-sapphire substrates with different initial growth conditions measured by surface-plasmon enhanced Raman scattering.

We have carried out surface-plasmon enhanced Raman spectroscopy (SERS) on 30 nm-thick GaN samples grown at various temperatures, in order to investigate the properties of ultra thin GaN films on sapphire. We found that the properties, such as the strain and the free-carrier density of the thin layers, were sensitively affected by the growth temperatures. Our results show that SERS, by selectively enhancing the Raman signal near the surface, can be a very useful technique to investigate the optical properties of ultra-thin GaN films and their initial growth mode.

[The determinants of the quality of life and pain of back pain patients].

OBJECTIVES: Because of the changing life style of Koreans, we have witnessed an increase of patients with back pain. The development of medical knowledge and technology has resulted in more numerous and better treatment methods. However, the outcomes of diverse treatments have been examined by using a few medicine-oriented measures like pain. This study aims at identifying the factors that influence the outcomes of back pain treatments by using two outcome measures (e.g., quality of life and pain). METHODS: We used the questionnaire survey method for data collection. The questionnaires contained 5 categories(treatment methods, clinical conditions, exercise, quality of life and, socio-demographic characteristics). We interviewed 188 back pain patients. We used the regression analysis method to predict the quality of life or pain. RESULTS: Surgery showed a statistically significant effect on the quality of life as well as pain. The illness period, age and exercise were turned out to be significant factors for both of the dependent variables. The social class and surgery methods showed a statistically significant effect solely on the quality of life. CONCLUSIONS: In choosing the surgical methods, doctors need to provide detailed explanations on the quality of life outcomes for each of the surgical methods to the patients.