Fourier-shape-based reconstruction of rock joint profile with realistic unevenness and waviness features

Rock joint shape characteristics,waviness and unevenness play essential but distinct roles in shear mechanism of rock joints.This study presents a novel method to generate virtual rock joint profiles with realistic waviness and unevenness features.Firstly,joint profiles are obtained by 3D laser scanning device.Secondly,quantification of waviness and unevenness is conducted by traditional method,including digital filtering technique and roughness parameter RL.Thirdly,the discrete Fourier transform(DFT)method is employed to analyze the joint outlines.Two representative Fourier shape descriptors(D3,D8)for characterization of waviness and unevenness are suggested.Then,the inverse discrete Fourier transform(IDFT)is adopted to reconstruct the joint profiles with random values of phase angles but prescribed amplitudes controlled by D3 and D8.The traditional method is then applied to the reconstructed joint profiles to examine statistically the relationships between D3 and D8 and parameters RL of waviness and unevenness,respectively.The results show that larger D8 tends to result in larger waviness while higher D3 tends to increase unevenness.Reference charts for estimation of waviness and unevenness with different pairs of D3 and D8 are also provided to facilitate implementation of random joint reconstruction.

Artfaroplasty with transplantation of autogenous rib perichondrium for reconstruction of metacarpophalangeal joint

Objective To evluate the outcome of arthropiasty with transplantation of autogenous rib perichondrium for reconstruction of the metacarpophalangeal joint. Methods From 1982 to 2000,15 patients undergoing arthropiasty with autogenous rib perichondrium were analyzed retrospectively. The pain, range of motion and stability of the joint was assessed. Results Thirteen patients were followed up with 2 in loss. The average follow-up was 4 years. The pain at the metacarpophalangeal joint disappeared after operation. The active range of motion in metacarpophalangeal joint was 40° -82°(average 58. 5°), with an average increase of 46°(35°-58°) when compared with those before operation. The patients all went to the original job. Conclusion The arthropiasty with autogenous rib perichondrium transplantation is an efficient and practical method for reconstruction of the metaracrpophalangeal joint. 5 refs.

Developing an enhanced recovery after surgery program for oncology patients who undergo hip or knee reconstruction surgery

Enhanced recovery after surgery(ERAS)protocols are applied in orthopedic surgery and are intended to reduce perioperative stress by implementing combined evidence-based practices with the cooperation of various health professionals as an interdisciplinary team.ERAS pathways include pre-operative patient counselling,regional anesthesia and analgesia techniques,post-operative pain management,early mobilization and early feeding.Studies have shown improvement in the recovery of patients who followed an ERAS program after hip or knee arthroplasty,compared with those who followed a traditional care approach.ERAS protocols reduce post-operative stress,contribute to rapid recovery,shorten length of stay(LOS)without increasing the complications or readmissions,improve patient satisfaction and decrease the hospital costs.We suggest that the ERAS pathway could reduce the LOS in hospital for patients undergoing total hip replacement or total knee replacement.These programs require good organization and handling by the multidisciplinary team.ERAS programs increase patient's satisfaction due to their active participation which they experience as personalized treatment.The aim of the study was to develop an ERAS protocol for oncology patients who undergo bone reconstruction surgeries using massive endoprosthesis,with a view to improving the surgical outcomes.

Joint DOA and polarization estimation for unequal power sources based on reconstructed noise subspace

In most literature about joint direction of arrival（DOA） and polarization estimation, the case that sources possess different power levels is seldom discussed. However, this case exists widely in practical applications, especially in passive radar systems. In this paper, we propose a joint DOA and polarization estimation method for unequal power sources based on the reconstructed noise subspace. The invariance property of noise subspace（IPNS） to power of sources has been proved an effective method to estimate DOA of unequal power sources. We develop the IPNS method for joint DOA and polarization estimation based on a dual polarized array. Moreover, we propose an improved IPNS method based on the reconstructed noise subspace, which has higher resolution probability than the IPNS method. It is theoretically proved that the IPNS to power of sources is still valid when the eigenvalues of the noise subspace are changed artificially. Simulation results show that the resolution probability of the proposed method is enhanced compared with the methods based on the IPNS and the polarimetric multiple signal classification（MUSIC） method. Meanwhile, the proposed method has approximately the same estimation accuracy as the IPNS method for the weak source.

A survey on distributed compressed sensing： theory and applications

The compressed sensing （CS） theory makes sample rate relate to signal structure and content. CS samples and compresses the signal with far below Nyquist sampling frequency simultaneously. However, CS only considers the intra-signal correlations, without taking the correlations of the multi-signals into account. Distributed compressed sensing （DCS） is an extension of CS that takes advantage of both the inter- and intra-signal correlations, which is wildly used as a powerful method for the multi-signals sensing and compression in many fields. In this paper, the characteristics and related works of DCS are reviewed. The framework of DCS is introduced. As DCS＇s main portions, sparse representation, measurement matrix selection, and joint reconstruction are classified and summarized. The applications of DCS are also categorized and discussed. Finally, the conclusion remarks and the further research works are provided.

Face transplantation for massive mandibular defects: considerations for allograft design and surgical planning

Modern face transplant techniques have advanced to allow for the transfer of vascularized skeletal components in addition to overlying soft tissue.This represents significant opportunity for individuals with mandibular defects that are not amenable to traditional reconstruction.Care must be taken when planning and executing transplants with these complex grafts,as satisfactory functional and aesthetic outcomes rely on achieving proper spatial relationships between the mandible,skull base,and midface.Which donor skeletal elements are included in the allograft and how they are harvested are important considerations in this planning and are associated with controversy.To optimize outcomes in the reconstruction of single-jaw defects,some advocate for transplantation of only the affected jaw while others support bimaxillary transplantation.Clinical evidence in this debate is not conclusive at this time.In current practice,including donor dentoalveolar anatomy by utilizing a bilateral sagittal split osteotomy of the mandible is favored to optimize outcomes such as dental occlusion.It has been suggested that harvesting the mandible at the level of the condyle or even the temporal bone may also be possible and may improve temporomandibular joint-related outcomes.Despite encouraging preclinical evidence,these strategies remain controversial.After allograft design,successful mandibular reconstruction with face transplantation relies on surgical precision in the donor and recipient procedures.Computerized surgical planning,computer-aided design and manufacturing,and intraoperative navigation are technologies currently in use to mitigate operative complexity.Results in both cadaveric and clinical face transplantations suggest these technologies are reliable and beneficial,although some room for improvement remains.