To be used as five-fingered myoelectric hands in daily living, robotic hands must be lightweight with the size of human hands. In addition, they must possess the DoFs （degrees of freedom） and high grip force similar...To be used as five-fingered myoelectric hands in daily living, robotic hands must be lightweight with the size of human hands. In addition, they must possess the DoFs （degrees of freedom） and high grip force similar to those of human hands. Balancing these requirements involves a trade-off; ideal robotic hands have yet to sufficiently satisfy both requirements. Herein, a power allocation mechanism is proposed to improve the grip force without increasing the size or weight of robotic hands by using redundant DoFs during pinching motions. Additionally, this mechanism is applied to an actual five-fingered myoelectric hand, which produces seven types of motions necessary for activities of daily living and realizes a -60% improvement in fingertip force, allowing three fingers to pinch objects exceeding 1 kg.展开更多
AIM: To examine the effects of one-handed phacoemulsification with steep-axis incision on corneal curvature and analyze surgically induced astigmatism(SIA) on the true net power, anterior and posterior corneal surface...AIM: To examine the effects of one-handed phacoemulsification with steep-axis incision on corneal curvature and analyze surgically induced astigmatism(SIA) on the true net power, anterior and posterior corneal surfaces. METHODS: Patients with cataracts underwent onehanded phacoemulsification with a 2.4-mm steep-axis of clear corneal incision(CCI) based on true net power. CCI was created under the guidance of Verion. Central corneal thickness(CCT), keratometry readings of the true net power and anterior and posterior corneal surface were obtained using Pentacam. Biometry, such as axial length, anterior chamber depth(ACD) and white-to-white(WTW) were performed using Lenstar pre-and 3 mo postoperatively. RESULTS: The study evaluated 68 eyes of 65 patients. The mean age was 65.93±9.40 y;CCT was 529.21±37.40 μm;WTW was 11.59±0.35 mm. Regarding true net power, keratometric value at the flattest corneal meridian for the 3-mm central zone(Ks) was significantly decreased postoperatively(P=0.031). Keratometric value at the steepest corneal meridian for the 3-mm central zone(Kf) was increased postoperatively(P>0.05). Astigmatism of true net power was 1.21±0.56 D preoperatively and significantly decreased to 1.02±0.58 D postoperatively(P=0.021). On the anterior corneal surface, no significant difference in Ks and Kf was noted pre-versus postoperatively. Anterior corneal astigmatism was 1.08±0.51 D preoperativelyand significantly decreased to 0.87±0.46 D postoperatively(P=0.002). On the posterior corneal surface, Ks and Kf were significantly increased postoperatively(all P<0.05), and posterior corneal astigmatism also increased(P=0.008). The SIA values of true net power and the anterior and posterior corneal surfaces at 3 mo postoperatively were 1.26±0.63 D(range: 0.11 to 2.80 D), 1.05±0.54 D(range: 0.23 to 2.40 D), and 0.21±0.17 D(range: 0.01 to 0.07 D), respectively. CONCLUSION: One-handed phacoemulsification with steep-axis incision can effectively decrease astigmatism of true net power and anterior corneal astigmatism. In the same surgery, the difference in personal SIA potentially originated from a difference in personal corneal thickness and diameter, both CCT and WTW distance should always be measured preoperatively when planning steep-axis phacoemulsification.展开更多
In this work, we derived the modal dispersion relation for TEm modes for a symmetric slab waveguide constructed from SiO2 dielectric guiding core material with lossy left-handed material (LHM) as cladding and substrat...In this work, we derived the modal dispersion relation for TEm modes for a symmetric slab waveguide constructed from SiO2 dielectric guiding core material with lossy left-handed material (LHM) as cladding and substrate, and the power confinement factor. The dispersion relations and the power confinement factor were numerically solved for a given set of parameters: allowed frequency range;core’s thicknesses;and TEm mode order. We found that the real part of the effective refractive index decreased with thickness and frequency increase. Moreover, the imaginary part (extinction coefficient) of the effective refractive index has very small values for all thickness in the frequency ranges, which means the waveguide structure is transparent for the used frequencies. The waveguide structure offers good guiding power for all thickness in the frequency range with low power attenuation. The real part of the effective refractive index increases with the increase of mode order, and the power confinement factor decreases with the increase of mode order.展开更多
A potato farmer was sent to prison just at the timewhen he should have been digging the ground for plantingthe new crop of potatoes. He knew that his wife wouldnot be strong enough to do the digging by herself, buttha...A potato farmer was sent to prison just at the timewhen he should have been digging the ground for plantingthe new crop of potatoes. He knew that his wife wouldnot be strong enough to do the digging by herself, butthat she could manage to do the pianting; and he alsoknew that he did not have any friends or neighbours whowould be willing to do the digging for him. So he展开更多
The surface wave dispersion relations of surface Plasmon at the interface of a left-handed material and a non-linear Kerr medium of arbitrary nonlinearity are derived based on a generalized first integral approach. Th...The surface wave dispersion relations of surface Plasmon at the interface of a left-handed material and a non-linear Kerr medium of arbitrary nonlinearity are derived based on a generalized first integral approach. The normalized power flow is also investigated for various values of frequency. The above study is conducted for both cases: self-focusing (α≺0) and de-focusing (α≻0) nonlinear Kerr coefficient.展开更多
We investigated the effectiveness and usefulness of a novel tool: the Power Tree?, for body massage in 10 healthy female volunteers (age range, 24 - 55 years;mean age, 40.5 years) by evaluating several dermatological ...We investigated the effectiveness and usefulness of a novel tool: the Power Tree?, for body massage in 10 healthy female volunteers (age range, 24 - 55 years;mean age, 40.5 years) by evaluating several dermatological and psychological parameters, such as the amount of dermal collagen, the skin temperature, the level of salivary amylase and the scores on the State-Trait Anxiety Index (STAI). After 60-minute Power Tree?-mediated body massage, both the dermal collagen score determined from the DermaLab? images and skin temperature measured by infrared thermography were found to have increased significantly in several body sites compared to those before the treatment (p < 0.01 and p < 0.001, respectively). Although the level of stress estimated by the amount of amylase in the saliva was not significantly different pre- and post-procedure (p = 0.3), the treatment significantly reduced both the state anxiety (SA) and trait anxiety (TA) scores on the STAI (p < 0.001 for the SA, p < 0.01 for the TA). The treatment with this device was smoothly performed without any burden on the therapists during the present study. These data suggest that the newly-developed device is a powerful and useful tool for reflexology when used for full body massage therapy, and massage therapy using this device may produce beneficial, physiological effects as well as psychosocial improvements.展开更多
We investigate the characteristics of electromagnetic wave reflection and transmission by multilayered structures consisting of a pair of left-handed material (LHM) and dielectric slabs inserted between two semi-infin...We investigate the characteristics of electromagnetic wave reflection and transmission by multilayered structures consisting of a pair of left-handed material (LHM) and dielectric slabs inserted between two semi-infinite dielectric media. The theoretical aspect is based on Maxwell's equations and matching the boundary conditions for the electric and magnetic fields of the incident waves at each layer interface. We calculate the reflected and transmitted powers of the multilayered structure taking into account the widths of the slabs and the frequency dependence of permittivity and permeability of the LHM. The obtained results satisfy the law of conservation of energy. We show that if the semi-infinite dielectric media have the same refractive index and the slabs have the same width, then the reflected (and transmitted) powers can be minimized (and maximized) and the powers-frequency curves show no ripple. On the other hand if the semi-infinite dielectric media have different values of refractive indices and the slabs have different widths, then under certain conditions the situation of minimum and maximum values of the mentioned powers will be reversed.展开更多
A four-layer slab waveguide including left-handed material is investigated numerically in this paper. Considering left-handed material dispersion, we find eight TE guided modes as frequency from 4 GHz to 6 GHz. The fu...A four-layer slab waveguide including left-handed material is investigated numerically in this paper. Considering left-handed material dispersion, we find eight TE guided modes as frequency from 4 GHz to 6 GHz. The fundamental mode can exist, and its dispersion curves are insensitive to the waveguide thickness. Besides, the total power fluxes of TE guided modes are analyzed and corresponding new properties are found, such as: positive and negative total power fluxes coexist;at maximum value of frequency, we find zero total power flux, etc. Our results may be of benefit to the optical waveguide technology.展开更多
文摘To be used as five-fingered myoelectric hands in daily living, robotic hands must be lightweight with the size of human hands. In addition, they must possess the DoFs （degrees of freedom） and high grip force similar to those of human hands. Balancing these requirements involves a trade-off; ideal robotic hands have yet to sufficiently satisfy both requirements. Herein, a power allocation mechanism is proposed to improve the grip force without increasing the size or weight of robotic hands by using redundant DoFs during pinching motions. Additionally, this mechanism is applied to an actual five-fingered myoelectric hand, which produces seven types of motions necessary for activities of daily living and realizes a -60% improvement in fingertip force, allowing three fingers to pinch objects exceeding 1 kg.
基金Supported by the Jiangsu Province Science and Technology Department of Social Development Major Projects-Key Diseases Standardization Diagnosis and Treatment Projects(No.BE2016699)
文摘AIM: To examine the effects of one-handed phacoemulsification with steep-axis incision on corneal curvature and analyze surgically induced astigmatism(SIA) on the true net power, anterior and posterior corneal surfaces. METHODS: Patients with cataracts underwent onehanded phacoemulsification with a 2.4-mm steep-axis of clear corneal incision(CCI) based on true net power. CCI was created under the guidance of Verion. Central corneal thickness(CCT), keratometry readings of the true net power and anterior and posterior corneal surface were obtained using Pentacam. Biometry, such as axial length, anterior chamber depth(ACD) and white-to-white(WTW) were performed using Lenstar pre-and 3 mo postoperatively. RESULTS: The study evaluated 68 eyes of 65 patients. The mean age was 65.93±9.40 y;CCT was 529.21±37.40 μm;WTW was 11.59±0.35 mm. Regarding true net power, keratometric value at the flattest corneal meridian for the 3-mm central zone(Ks) was significantly decreased postoperatively(P=0.031). Keratometric value at the steepest corneal meridian for the 3-mm central zone(Kf) was increased postoperatively(P>0.05). Astigmatism of true net power was 1.21±0.56 D preoperatively and significantly decreased to 1.02±0.58 D postoperatively(P=0.021). On the anterior corneal surface, no significant difference in Ks and Kf was noted pre-versus postoperatively. Anterior corneal astigmatism was 1.08±0.51 D preoperativelyand significantly decreased to 0.87±0.46 D postoperatively(P=0.002). On the posterior corneal surface, Ks and Kf were significantly increased postoperatively(all P<0.05), and posterior corneal astigmatism also increased(P=0.008). The SIA values of true net power and the anterior and posterior corneal surfaces at 3 mo postoperatively were 1.26±0.63 D(range: 0.11 to 2.80 D), 1.05±0.54 D(range: 0.23 to 2.40 D), and 0.21±0.17 D(range: 0.01 to 0.07 D), respectively. CONCLUSION: One-handed phacoemulsification with steep-axis incision can effectively decrease astigmatism of true net power and anterior corneal astigmatism. In the same surgery, the difference in personal SIA potentially originated from a difference in personal corneal thickness and diameter, both CCT and WTW distance should always be measured preoperatively when planning steep-axis phacoemulsification.
文摘In this work, we derived the modal dispersion relation for TEm modes for a symmetric slab waveguide constructed from SiO2 dielectric guiding core material with lossy left-handed material (LHM) as cladding and substrate, and the power confinement factor. The dispersion relations and the power confinement factor were numerically solved for a given set of parameters: allowed frequency range;core’s thicknesses;and TEm mode order. We found that the real part of the effective refractive index decreased with thickness and frequency increase. Moreover, the imaginary part (extinction coefficient) of the effective refractive index has very small values for all thickness in the frequency ranges, which means the waveguide structure is transparent for the used frequencies. The waveguide structure offers good guiding power for all thickness in the frequency range with low power attenuation. The real part of the effective refractive index increases with the increase of mode order, and the power confinement factor decreases with the increase of mode order.
文摘A potato farmer was sent to prison just at the timewhen he should have been digging the ground for plantingthe new crop of potatoes. He knew that his wife wouldnot be strong enough to do the digging by herself, butthat she could manage to do the pianting; and he alsoknew that he did not have any friends or neighbours whowould be willing to do the digging for him. So he
文摘The surface wave dispersion relations of surface Plasmon at the interface of a left-handed material and a non-linear Kerr medium of arbitrary nonlinearity are derived based on a generalized first integral approach. The normalized power flow is also investigated for various values of frequency. The above study is conducted for both cases: self-focusing (α≺0) and de-focusing (α≻0) nonlinear Kerr coefficient.
文摘We investigated the effectiveness and usefulness of a novel tool: the Power Tree?, for body massage in 10 healthy female volunteers (age range, 24 - 55 years;mean age, 40.5 years) by evaluating several dermatological and psychological parameters, such as the amount of dermal collagen, the skin temperature, the level of salivary amylase and the scores on the State-Trait Anxiety Index (STAI). After 60-minute Power Tree?-mediated body massage, both the dermal collagen score determined from the DermaLab? images and skin temperature measured by infrared thermography were found to have increased significantly in several body sites compared to those before the treatment (p < 0.01 and p < 0.001, respectively). Although the level of stress estimated by the amount of amylase in the saliva was not significantly different pre- and post-procedure (p = 0.3), the treatment significantly reduced both the state anxiety (SA) and trait anxiety (TA) scores on the STAI (p < 0.001 for the SA, p < 0.01 for the TA). The treatment with this device was smoothly performed without any burden on the therapists during the present study. These data suggest that the newly-developed device is a powerful and useful tool for reflexology when used for full body massage therapy, and massage therapy using this device may produce beneficial, physiological effects as well as psychosocial improvements.
文摘We investigate the characteristics of electromagnetic wave reflection and transmission by multilayered structures consisting of a pair of left-handed material (LHM) and dielectric slabs inserted between two semi-infinite dielectric media. The theoretical aspect is based on Maxwell's equations and matching the boundary conditions for the electric and magnetic fields of the incident waves at each layer interface. We calculate the reflected and transmitted powers of the multilayered structure taking into account the widths of the slabs and the frequency dependence of permittivity and permeability of the LHM. The obtained results satisfy the law of conservation of energy. We show that if the semi-infinite dielectric media have the same refractive index and the slabs have the same width, then the reflected (and transmitted) powers can be minimized (and maximized) and the powers-frequency curves show no ripple. On the other hand if the semi-infinite dielectric media have different values of refractive indices and the slabs have different widths, then under certain conditions the situation of minimum and maximum values of the mentioned powers will be reversed.
文摘A four-layer slab waveguide including left-handed material is investigated numerically in this paper. Considering left-handed material dispersion, we find eight TE guided modes as frequency from 4 GHz to 6 GHz. The fundamental mode can exist, and its dispersion curves are insensitive to the waveguide thickness. Besides, the total power fluxes of TE guided modes are analyzed and corresponding new properties are found, such as: positive and negative total power fluxes coexist;at maximum value of frequency, we find zero total power flux, etc. Our results may be of benefit to the optical waveguide technology.
