Vision-Based Efficient Robotic Manipulation with a Dual-Streaming Compact Convolutional Transformer.

Learning from visual observation for efficient robotic manipulation is a hitherto significant challenge in Reinforcement Learning (RL). Although the collocation of RL policies and convolution neural network (CNN) visual encoder achieves high efficiency and success rate, the method general performance for multi-tasks is still limited to the efficacy of the encoder. Meanwhile, the increasing cost of the encoder optimization for general performance could debilitate the efficiency advantage of the original policy. Building on the attention mechanism, we design a robotic manipulation method that significantly improves the policy general performance among multitasks with the lite Transformer based visual encoder, unsupervised learning, and data augmentation. The encoder of our method could achieve the performance of the original Transformer with much less data, ensuring efficiency in the training process and intensifying the general multi-task performances. Furthermore, we experimentally demonstrate that the master view outperforms the other alternative third-person views in the general robotic manipulation tasks when combining the third-person and egocentric views to assimilate global and local visual information. After extensively experimenting with the tasks from the OpenAI Gym Fetch environment, especially in the Push task, our method succeeds in 92% versus baselines that of 65%, 78% for the CNN encoder, 81% for the ViT encoder, and with fewer training steps.

Reference Frame Unification of IMU-Based Joint Angle Estimation: The Experimental Investigation and a Novel Method.

Inertial measurement unit (IMU)-based joint angle estimation is an increasingly mature technique that has a broad range of applications in clinics, biomechanics and robotics. However, the deviations of different IMUs' reference frames, referring to IMUs' individual orientations estimating errors, is still a challenge for improving the angle estimation accuracy due to conceptual confusion, relatively simple metrics and the lack of systematical investigation. In this paper, we clarify the determination of reference frame unification, experimentally study the time-varying characteristics of reference frames' deviations and accordingly propose a novel method with a comprehensive metric to unify reference frames. To be specific, we firstly define the reference frame unification (RFU) and distinguish it with drift correction that has always been confused with the term RFU. Secondly, we design a mechanical gimbal-based experiment to study the deviations, where sensor-to-body alignment and rotation-caused differences of orientations are excluded. Thirdly, based on the findings of the experiment, we propose a novel method to utilize the consistency of the joint axis under the hinge-joint constraint, gravity acceleration and local magnetic field to comprehensively unify reference frames, which meets the nonlinear time-varying characteristics of the deviations. The results on ten human subjects reveal the feasibility of our proposed method and the improvement from previous methods. This work contributes to a relatively new perspective of considering and improving the accuracy of IMU-based joint angle estimation.

Estimating Three-Dimensional Body Orientation Based on an Improved Complementary Filter for Human Motion Tracking.

Rigid body orientation determined by IMU (Inertial Measurement Unit) is widely applied in robotics, navigation, rehabilitation, and human-computer interaction. In this paper, aiming at dynamically fusing quaternions computed from angular rate integration and FQA algorithm, a quaternion-based complementary filter algorithm is proposed to support a computationally efficient, wearable motion-tracking system. Firstly, a gradient descent method is used to determine a function from several sample points. Secondly, this function is used to dynamically estimate the fusion coefficient based on the deviation between measured magnetic field, gravity vectors and their references in Earth-fixed frame. Thirdly, a test machine is designed to evaluate the performance of designed filter. Experimental results validate the filter design and show its potential of real-time human motion tracking.

One-sided hip-preserving and concurrent contralateral total hip arthroplasty for the treatment of bilateral osteonecrosis of the femoral head in different stages: short-medium term outcomes.

BACKGROUND: We aimed to evaluate the clinical and radiological short-medium term outcomes for the treatment of bilateral osteonecrosis of the femoral head (ONFH) with hip-preserving surgery of core decompression followed by tightly impaction bone grafting combining with non-vascularized fibular allografting in one hip and concurrent one-stage total hip arthroplasty (THA) in the contralateral side. We hypothesized the aforementioned surgery showed benefits of protecting the preserved hip from collapsing and thereafter THA was delayed or avoided. METHODS: We retrospectively reviewed a consecutive series of 18 non-traumatic bilateral ONFH patients (36 hips) who had undergone previous mentioned surgeries between July 2004 and June 2013. Preoperative and the last follow-up Harris Hip Score (HHS) and Visual Analogue Scale (VAS) Score were obtained for clinical outcomes evaluation and X-rays of antero-posterior and frog-leg lateral views of bilateral hips were compared for radiological outcomes assessment. RESULTS: All patients were telephone contacted for out-patient clinic return visit at an average follow-up time of 53.3 months (ranged from 20 months to 107 months). Of the 18 patients (15 men and 3 women), there were 5 patients were diagnosed preoperative IIB stages according to classification of the Association Research Circulation Osseuse classification (ARCO) and the remaining 13 patients were in ARCO IIIC stages. The mean age of the included patients was 40.7 years (range from 22 to 59 years). No age and followed-up time difference existed in genders. The postoperative HHS were 83.8 ± 17.9 points, and it revealed statistical significance when compared to preoperative 61.6 ± 17.0 points (p < 0.05). The VAS scores were reduced from preoperative 6.2 ± 2.0 points to postoperative 2.8 ± 2.3 points, which also manifested outcomes significance (p < 0.05). From radiological aspects, 14 patients acquired well repairmen of the necrotic areas of the femoral head. However, the other 4 patients ultimately suffered femoral head collapse, and the severe pain was gotten rid of after THA surgeries were performed. CONCLUSIONS: The un-collapsed hip can achieve biological stability and sufficient blood supply through the hip-preserving surgery and obtain longtime repairmen of the necrotic bone as well as early non-weight-bearing function training, which benefits from distributing the whole body weight load to the hip of one-stage THA. Consequently, we recommend this sort of surgery for clinical practice trial when faced bilateral ONFH in different stages though longer time follow-up and larger samples are essentially needed to address its efficacy.

An Adaptively Weighted Averaging Method for Regional Time Series Extraction of fMRI-based Brain Decoding.

Brain decoding that classifies cognitive states using the functional fluctuations of the brain can provide insightful information for understanding the brain mechanisms of cognitive functions. Among the common procedures of decoding the brain cognitive states with functional magnetic resonance imaging (fMRI), extracting the time series of each brain region after brain parcellation traditionally averages across the voxels within a brain region. This neglects the spatial information among the voxels and the requirement of extracting information for the downstream tasks. In this study, we propose to use a fully connected neural network that is jointly trained with the brain decoder to perform an adaptively weighted average across the voxels within each brain region. We perform extensive evaluations by cognitive state decoding, manifold learning, and interpretability analysis on the Human Connectome Project (HCP) dataset. The performance comparison of the cognitive state decoding presents an accuracy increase of up to 5% and stable accuracy improvement under different time window sizes, resampling sizes, and training data sizes. The results of manifold learning show that our method presents a considerable separability among cognitive states and basically excludes subject-specific information. The interpretability analysis shows that our method can identify reasonable brain regions corresponding to each cognitive state. Our study would aid the improvement of the basic pipeline of fMRI processing.

Tanshinone I attenuates estrogen-deficiency bone loss via inhibiting RANKL-induced MAPK and NF-κB signaling pathways.

AIM OF THE STUDY: This study aims to reveal the role of Tanshinone I (TI) in inhibiting osteoclast activity and bone loss in vitro and in vivo, as well as elucidate its underlying molecular mechanism. MATERIALS AND METHODS: A mouse model of estrogen deficiency was used to assess the inhibitory effect of TI on osteoclast activity and subsequent bone loss. To validate the impact of TI on osteoclast formation, TRAcP staining and pseudopodia belt staining were conducted. The expressions of osteoclast-specific genes and proteins were evaluated using RT-PCR and Western Blot analyses. Additionally, immunofluorescence staining was employed to examine the effect of TI on p65 nuclear translocation and the expression level of reactive oxygen species (ROS). RESULTS: TI demonstrated significant efficacy in alleviating bone mass loss and suppressing osteoclast activity and function in ovariectomized mice. This outcome was predominantly ascribed to a decrease in ROS levels, thereby impeding the NF-κB signaling pathway and the translocation of p65 to the nucleus. Additionally, TI hindered the RANKL-induced phosphorylation of the MAPK signaling pathway. Moreover, TI played a role in the reduction of osteoclast-specific genes and proteins. CONCLUSIONS: To summarize, this study sheds light on TI's capacity to modulate various signaling pathways triggered by RANKL, effectively impeding osteoclast formation and mitigating bone loss resulting from estrogen deficiency. Consequently, TI emerges as a promising therapeutic option for estrogen-deficiency bone loss.

Mordo2: A Personalization Framework for Silent Command Recognition.

Wearable human-computer interactions in daily life are increasingly encouraged by the prevalence of intelligent wearables. It poses a demanding requirement of micro-interaction and minimizing social awkwardness. Our previous work demonstrated the feasibility of recognizing silent commands through around-ear biosensors with the limitation of user adaptation. In this work, we ease the limitation by a personalization framework that integrates spectral factorization of signals, temporal confidence rejection and commonly used transfer learning algorithms. Specifically, we first empirically formulate the user adaptation issue by presenting the accuracies of applying transfer learning algorithms to our previous method. Second, we improve the signal-to-noise ratio by proposing the supervised spectral factorization method that learns the amplitude and phase mappings between around-ear signals and the signals of articulated facial muscles. Third, we leverage the time continuity of commands and introduce the time decay into confidence rejection. Finally, extensive experiments have been conducted to evaluate the feasibility and improvements. The results indicate an average accuracy of 92.38% which is significantly larger than solely using transfer learning algorithms. And a comparable accuracy can be achieved with significantly reduced data of new users. The overall performance shows the framework can significantly improve the accuracy of user adaptations. The work would aid a further step toward commercial products for silent command recognition and inspire the solution to the user adaptation challenge of wearable human-computer interactions.

Clinical efficacy analysis of percutaneous "tripod" combined with radiofrequency ablation and bone cement filling in the treatment of periacetabular metastases.

BACKGROUND: To investigate the clinical efficacy of a percutaneous "tripod" combined with radiofrequency ablation and bone cement filling surgery in treating acetabular bone metastases. METHODS: We retrospectively analyzed 11 patients who underwent percutaneous "tripod" combined with radiofrequency ablation and bone cement filling for acetabular bone metastases at a tertiary care hospital from February 2021 to December 2022. RESULTS: 11 cases with 13 hips underwent this procedure, including two female patients who underwent both sides, and the rest were unilateral. All cases were followed up for 3-24 months, with a mean of 12 months and a median follow-up time of 11 months. Two of the 11 patients died by the final follow-up, and nine survived. One died 7 months after surgery, and one died 8 months after surgery; the survival of the deceased patients was 7.5 months (range: 7-8 months), with a median survival time of 7.5 months. All 11 patients completed the surgery successfully, and the average unilateral operation time was 167.4 min (148-193). The amelioration of postoperative pain, concomitant with improved quality of life, was observed significantly, ultimately resulting in a prolonged and sustained effect. CONCLUSIONS: The combination of percutaneous "tripod", radiofrequency ablation, and bone cement filling can effectively relieve pain without delaying the patient's systemic anti-tumor therapy and is a minimally invasive, safe, and effective procedure for the treatment of periacetabular metastases.

Knee Flexion-Assisted Method for Human-Exoskeleton System.

The knee has gradually become an important research target for the lower extremity exoskeleton. However, the issue that whether the flexion-assisted profile based on the contractile element (CE) is effective throughout the gait is still a research gap. In this study, we first analyze the effective flexion-assisted method through the passive element's (PE) energy storage and release mechanism. Specifically, ensuring assisting within an entire joint power period and the human's active movement is a prerequisite for the CE-based flexion-assisted method. Second, we design the enhanced adaptive oscillator (EAO) to ensure the human's active movement and the integrity of the assistance profile. Third, a fundamental frequency estimation based on discrete Fourier transform (DFT) is proposed to shorten the convergence time of EAO significantly. The finite state machine (FSM) is designed to improve the stability and practicality of EAO. Finally, we demonstrate the effectiveness of the prerequisite condition for the CE-based flexion-assisted method by using electromyography (EMG) and metabolic indicators in experiments. In particular, for the knee joint, CE-based flexion assistance should be within an entire joint power period rather than just in the negative power phase. Ensuring the human's active movement will also significantly reduce the activation of antagonistic muscles. This study will aid in designing assistive methods from the perspective of natural human actuation and apply the EAO to the human-exoskeleton system.

Multidisciplinary treatment of giant presacral solitary fibrous tumour: a case report and literature review.

Solitary fibrous tumours (SFTs) usually occur at the pleura. Extrapleural sites, particularly giant extrapleural solitary fibromas, are more rarely observed in the clinic, and the clinical diagnosis and treatment of this disease is a focus of attention. Herein, the case of a 43-year-old male patient with giant presacral SFT successfully treated by open surgery, and with a final diagnosis confirmed by postoperative pathology and immunohistochemistry, is reported. The patient was followed-up regularly during 5 years after surgery, with no obvious surgical complications, and no tumour recurrence noted on pelvic magnetic resonance imaging. This case provides clinical information that may help in the diagnosis and treatment of complex SFT.

A Novel sEMG-Based Gait Phase-Kinematics-Coupled Predictor and Its Interaction With Exoskeletons.

The interaction between human and exoskeletons increasingly relies on the precise decoding of human motion. One main issue of the current motion decoding algorithms is that seldom algorithms provide both discrete motion patterns (e.g., gait phases) and continuous motion parameters (e.g., kinematics). In this paper, we propose a novel algorithm that uses the surface electromyography (sEMG) signals that are generated prior to their corresponding motions to perform both gait phase recognition and lower-limb kinematics prediction. Particularly, we first propose an end-to-end architecture that uses the gait phase and EMG signals as the priori of the kinematics predictor. In so doing, the prediction of kinematics can be enhanced by the ahead-of-motion property of sEMG and quasi-periodicity of gait phases. Second, we propose to select the optimal muscle set and reduce the number of sensors according to the muscle effects in a gait cycle. Finally, we experimentally investigate how the assistance of exoskeletons can affect the motion intent predictor, and we propose a novel paradigm to make the predictor adapt to the change of data distribution caused by the exoskeleton assistance. The experiments on 10 subjects demonstrate the effectiveness of our algorithm and reveal the interaction between assistance and the kinematics predictor. This study would aid the design of exoskeleton-oriented motion-decoding and human-machine interaction methods.

Preliminary proposal: a classification system for reconstruction with autologous femoral head after periacetabular tumors resection.

BACKGROUND: Although researchers have adopted various methods for the resection and reconstruction of periacetabular tumors, the total incidence rate of complications remains high. Aiming for preserving the acetabulum and reducing the risk of complications, we applied a surgery method using tumor-free autologous femoral head to reconstruct the defective acetabulum after resection of periacetabular tumors followed by performing a conventional total hip arthroplasty (THA). Moreover, we proposed a preliminary classification system for these surgery methods. METHODS: We retrospectively reviewed 6 patients treated with acetabulum reconstruction combined with autologous femoral head following peri-acetabulum resection between April 2010 and May 2018. All patients were diagnosed as periacetabular tumors including chondrosarcoma (n = 5) and chondroblastoma (n = 1). Clinical data such as age, diagnosis, complications, local recurrence or metastasis, and function (Musculoskeletal Tumor Society 1993, MSTS93) were documented. The average time of follow-up was 62.5 months (range, 17 to 106 months). RESULTS: A total of 5 patients survive with average MSTS93 score of 27.8 points (range, 26-30). One patient, suffering from multiple bone metastasis prior treatment, ended up dying. One who had received radiotherapy before surgery had poor incision healing. Further, a classification system was preliminary proposed in 2 patients involving the pubis (type A) and 4 patients involving ischium (type B). CONCLUSIONS: Based on the results, we preliminary proposed a classification system for reconstruction with autologous femoral head after periacetabular low malignant tumors resection. The clinical results suggested that surgery methods involving pubis (type A) and ischium (Type B) are safe and feasible. However, further researches should be conducted to verify our classification system.

lncRNA-TINCR Functions as a Competitive Endogenous RNA to Regulate the Migration of Mesenchymal Stem Cells by Sponging miR-761.

Mounting evidences have indicated that terminal differentiation-induced lncRNA (TINCR) contributes to various cellular processes, such as proliferation, apoptosis, autophagy, migration, invasion, and metastasis. However, the function of TINCR in regulating migration of MSCs is largely unknown. In this study, the effects of TINCR on the migration of rat MSCs from the bone marrow were studied by Transwell assays and wound healing assays. Our results suggested that TINCR positively regulated migration of rMSCs. miR-761 mimics suppressed rMSC migration, whereas miR-761 inhibitor promoted migration. Target prediction analysis tools and dual-luciferase reporter gene assay identified Wnt2 as a direct target of miR-761. miR-761 could inhibit the expression of Wnt2. Further, the investigation about the function of TINCR in miR-761-induced migration of rMSCs was completed. These results demonstrated that TINCR took part in the regulation of miR-761-induced migration in rMSCs through the regulation of Wnt2 and its Wnt2 signaling pathway. Taken together, our results demonstrate that lncRNA-TINCR functions as a competitive endogenous RNA (ceRNA) to regulate the migration of rMSCs by sponging miR-761 which modulates the role of Wnt2. These findings provide evidence that lncRNA-TINCR has a chance to serve as a potential target for enhancing MSC homing through the miR-761/Wnt2 signaling pathway.

[Combined epiphyseal preservation and autograft bone transfer in treatment of children osteosarcoma].

OBJECTIVE: To investigate the clinical application and early results of combined epiphyseal preservation. METHODS: Between March 2010 and March 2011, and autograft bone transfer for limb salvage in children with osteosarcoma. 3 children with osteosarcoma were treated with epiphyseal preservation and autograft bone transfer. There were 1 boy and 2 girls with the age of 10-14 years. The disease duration was 2 weeks to 3 months. The tumors were rated as type II according to San-Julian radiological classification and as type IIB according to Enneking surgical classification. The locations were the distal femur in 1 case and the proximal tibia in 2 cases. The surgical technique included preoperative neoadjuvant chemotherapy, excision of part of the epiphysis, preservation of subarticular epi physis, external fixation with Ilizarov apparatus and transport osteogenesis treatment. Safe excision border was confirmed by histological examination. Postoperative observation included the wound healing, local recurrence or distant metastasis, length, speed, alignment, and regeneration of transplanted bone, the length and function of the affected limb. RESULTS: The postoperative histological examination proved the safe surgical margin in all 3 patients. The incision healing by first intention was obtained at distal femur in 1 case and by second intention at proximal tibia in 2 cases at 4 weeks after changes of dressing. Three patients were followed up 12, 18, and 24 months, respectively. There was no local recurrence or distant metastasis during follow-up. Two cases had pin-tract infection at 10 months after external fixation and were cured after changes of dressing and antibiotics administration. The length of transplanted osteogenisis was 18.0, 9.5, and 16.0 cm, respectively. The speed of lengthening was 2.57, 2.07, and 1.20 cm/month, respectively. One patient had alignment deviation during lengthening, which was adjusted under anaesthesia. Bony healing was achieved at 8 months after lengthening end in 2 cases and external fixation was removed; 1 patient had poor bone growth and was given retraction for promoting bone growth. At last follow-up, the length of the affected limbs was 1.0-1.5 cm shorter than that of normal limbs, but no abnormalities was observed at donor sites. The affected knee flexion reached 90 degrees and 120 degrees in 2 patients and poor knee function was observed in 1 patient for external fixation. CONCLUSION: The combined epiphyseal preservation and transport osteogenesis technique can be used for bone defect repair by lengthening the residual bone. It is a promising limb salvage treatment for children with osteosarcoma.

[Experimental study of directional differentiation of bone mesenchymal stem cells (BMSCs) to osteoblasts guided by serum containing cistanche deserticola].

OBJECTIVE: To study directional differentiation of BMSCs guided by Desert living Cistanche (Herba Cistanches) which invigorates the kidney. METHODS: Primary BMSCs were obtained by whole bone marrow culture and subcultured to the fourth generation by trypsin digestion, and than inoculated into two six-well plates at 5 x 10(6) cells per milliliter, all the plates were divided into three groups as blank group, Dexamethasone (DXM) group and Herba Cistanches group, three wells in each group, medium were changed at day 2. The blank group were changed with L-DMEM containing 10% FBS. The DXM group were changed with medium containing 10 mmol/L beta-sodium glycerophosphate, 0.1 micromol/L DXM and 50 mg/L vitamin C. The Herba Cistanches group were changed with medium containing 10% blood serum containing Herba Cistanches and L-DMEM. One of the six-well plates was stained by alkaline phosphatase (AKP) at the tenth day,the other one was stained by alizarin Bordeaux at the twentieth day. RESULTS: At the tenth day DXM group and Herba Cistanches group were ALKP stained positive; from the 12th day,white calcium nodus could be seen at the surface of the wells; which alizarin stained positive by the twentyth day. CONCLUSION: The medium containing Herba Cistanches can guide BMSCs to differentiate into osteoblast, which promises a favorable prospect for the treatment of osteoporosis and bone fracture disunion.