A novel miniature flexible robotic system for endoscopic mucosal dissection: an animal experimental study.

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastrointestinal cancer due to its higher rate of en-bloc resection and lower recurrence rate. However, the technical challenges lead to long learning curve and high risks of adverse events. A gastrointestinal flexible robotic-tool system (GIFTS) was proposed to reduce the difficulty and shorten the learning curve of novices. This is an animal study to evaluate the feasibility of GIFTS in ESD. The GIFTS provides a total of 13 degrees of freedom within 10 mm in diameter and variable stiffness function to achieve endoscopic intervention and submucosal dissection with the cooperation of two flexible robotic instruments. One esophageal and four colorectal ESDs in five porcine models were performed. In all five ESD procedures, the GIFTS was successfully intubated and submucosal dissection was completed without perforation or significant bleeding, and there was no system fault. The mean operative time was 99 min, and the mean size of the specimen was 151 mm2. The fifth experiment showed significantly better results than the first one. In vivo animal experiments confirmed the feasibility of GIFTS in performing ESD. The control of GIFTS is friendly to inexperienced beginners, which will help reduce the technical challenges of ESD and shorten the learning curve of endoscopists.

Cultureless enumeration of live bacteria in urinary tract infection by single-cell Raman spectroscopy.

Urinary tract infections (UTIs) are the most common outpatient infections. Obtaining the concentration of live pathogens in the sample is crucial for the treatment. Still, the enumeration depends on urine culture and plate counting, which requires days of turn-around time (TAT). Single-cell Raman spectra combined with deuterium isotope probing (Raman-DIP) has been proven to identify the metabolic-active bacteria with high accuracy but is not able to reveal the number of live pathogens due to bacteria replication during the Raman-DIP process. In this study, we established a new approach of using sodium acetate to inhibit the replication of the pathogen and applying Raman-DIP to identify the active single cells. By combining microscopic image stitching and recognition, we could further improve the efficiency of the new method. Validation of the new method on nine artificial urine samples indicated that the exact number of live pathogens obtained with Raman-DIP is consistent with plate-counting while shortening the TAT from 18 h to within 3 h, and the potential of applying Raman-DIP for pathogen enumeration in clinics is promising.

A variable stiffness manipulator with multifunctional channels for endoscopic submucosal dissection.

PURPOSE: Endoscopic submucosal dissection (ESD) has become the main treatment for early esophageal and gastric cancers, but the insufficient stiffness and large diameter of current devices increase the difficulty in operation. To address the above problems, this study proposes a variable stiffness manipulator with multifunctional channels for ESD. METHODS: The proposed manipulator has a diameter of just 10 mm and highly integrates a CCD camera, two optical fibers, two channels for instruments, and one channel for water and gas. Additionally, a compact wire-driven variable stiffness mechanism is also integrated. The drive system of the manipulator is designed, and the kinematics and workspace are analyzed. The variable stiffness and practical application performance of the robotic system are tested. RESULTS: The motion tests verify that the manipulator has sufficient workspace and motion accuracy. The variable stiffness tests show that the manipulator achieves 3.55 times of stiffness variation instantly. Further insertion tests and operation test demonstrates that the robotic system is safe and can satisfy the needs in motion, stiffness, channels, image, illumination, and injection. CONCLUSION: The manipulator proposed in this study highly integrates six functional channels and a variable stiffness mechanism in a 10 mm diameter. After kinematic analysis and testing, the performance and application prospect of the manipulator are verified. The proposed manipulator can promote the stability and accuracy of ESD operation.

Design of a dexterous robotic surgical instrument with a novel bending mechanism.

BACKGROUND: The robot-assisted minimally invasive surgery (RMIS) has developed rapidly in recent years, requiring highly articulated instruments to enable surgeons to perform complicated and precise procedures. METHODS: A novel wrist-type surgical instrument was proposed for RMIS. The wrist consists of superelastic-wire-driven snake-like joints and universal joints, which could perform two deflections and one distal rotation. The bending mechanism and the kinematics of universal joints were analysed. The forward and inverse kinematics of the wrist were derived. RESULTS: The performances of the instrument were evaluated using a prototype by experiments. The average motion deviation of the wrist's deflection was 0.15 ± 0.08 mm, and the maximum deviation was 0.52 mm. The maximum payload capability was 10 N. The suture task and ex vivo procedure verified the effectiveness of the instrument. CONCLUSIONS: The proposed instrument has high dexterity and payload capability, which contributes to improving the quality of the RMIS procedures.

Robot-assisted sleeve gastrectomy in patients with obesity with a novel Chinese domestic MicroHand SII surgical system.

BACKGROUND: A new device has been added to the Chinese MicroHand surgical robot family, developed based on the successful application of control algorithms. As a benefit of using these specialized control algorithms, the motion mapping relation can be accommodated into the system without the help of a built-in image system, resulting in a novel Chinese domestic surgical robot with two arms called MicroHand SII, which is different from the former MicroHand S and da Vinci systems. In this study, we investigate the performance of a novel MicroHand SII robotic platform in patients with obesity. METHODS: From March 2018 to April 2019, a total of 7 patients whose BMI ranged from 29.9 to 49.8 kg/m2 were operated on with the robot-assisted technique using the MicroHand SII surgical system. Data regarding demography, surgical procedure and the 3-month outcome postoperation were collected. RESULTS: There were 2 female and 5 male patients with a median age (range) of 35 (20-51) years. The median operative time was 160 (149-195) minutes. None were converted to open surgery. All anthropometry indices improved significantly (p < 0.05) at 3 months postoperatively. There were no cases of surgical site infection, gastrointestinal/abdominal bleeding, or conversion to an open operation. CONCLUSIONS: The initial experience showed that the Chinese domestic robot surgical system MicroHand SII could be feasibly and safely applied in sleeve gastrectomy in patients with obesity. Because of the unique design of this system such as a two-hand robot, an array of master-slave motion strategies, and a roll joint at the end of the instruments that allows 7 degrees of freedom, this robotic platform has presented its own obvious advantages.

Design and implementation of a hand-held robot-assisted minimally invasive surgical device with enhanced intuitive manipulability and stable grip force.

BACKGROUND: The conventional hand-held minimally invasive surgical devices commonly suffer from non-intuitive manipulability and restricted flexibility for operation. METHODS: A hand-held surgical device with enhanced intuitive manipulability and stable grip force was proposed for minimally invasive surgery (MIS). The dexterous instrument and isomorphic handle were designed, and the cable transmission structure and model of the instrument were analysed. A modelling method for grip force pre-compensation was proposed to produce stable grip forces under different posture. RESULTS: The prototype of the proposed MIS device was developed, and the related experiments were carried out. The maximum opening angle error was 1.2°. Compared with the non-compensation model, the variation of grip force reduced 8 times with the pre-compensation model. The animal vivo experiments verified the feasibility and practicability of the device. CONCLUSIONS: The proposed hand-held device could provide intuitive manipulability and stable operation, which contributes to the performance improvement of the MIS.

Peroxotantalate-Based Ionic Liquid Catalyzed Epoxidation of Allylic Alcohols with Hydrogen Peroxide.

The efficient and environmentally benign epoxidation of allylic alcohols has been attained by using new kinds of monomeric peroxotantalate anion-functionalized ionic liquids (ILs=[P4,4,4,n ]3 [Ta(O)3 (η-O2 )], P4,4,4,n =quaternary phosphonium cation, n=4, 8, and 14), which have been developed and their structures determined accordingly. This work revealed the parent anions of the ILs underwent structural transformation in the presence of H2 O2 . The formed active species exhibited excellent catalytic activity, with a turnover frequency for [P4,4,4,4 ]3 [Ta(O)3 (η-O2 )] of up to 285 h-1 , and satisfactory recyclability in the epoxidation of various allylic alcohols under very mild conditions by using only one equivalent of hydrogen peroxide as an oxidant. NMR studies showed the reaction was facilitated through a hydrogen-bonding mechanism, in which the peroxo group (O-O) of the peroxotantalate anion served as the hydrogen-bond acceptor and hydroxyl group in the allylic alcohols served as the hydrogen-bond donor. This work demonstrates that simple monomeric peroxotantalates can catalyze epoxidation of allylic alcohols efficiently.

Cervical spinal functional magnetic resonance imaging of the spinal cord injured patient during electrical stimulation.

PURPOSE: To evaluate the spatial distribution and signal intensity changes following spinal cord activation in patients with spinal cord injury. METHODS: This study used spinal functional magnetic resonance imaging (fMRI) based on signal enhancement by extra-vascular water protons (SEEP) to assess elicited responses during subcutaneous electrical stimulation at the right elbow and right thumb in the cervical spinal cord. RESULTS: Seven healthy volunteers and seven patients with cervical spinal cord injury (SCI) were included in this study. Significant functional activation was observed mainly in the right side of the spinal cord at the level of the C5-C6 cervical vertebra in both the axial and sagittal planes. A higher percentage of signal changes (4.66 ± 2.08 % in injured subjects vs. 2.78 ± 1.66 % in normal) and more average activation voxels (4.69 ± 2.59 in injured subjects vs. 2.56 ± 1.13 in normal subject) in axial plane at the C5-C6 cervical vertebra with a statistically significant difference. The same trends were observed in the sagittal plane with higher percentage of signal changes and more average activation voxels, though no statistically significant difference compared with the control group. CONCLUSIONS: Spinal SEEP fMRI is a powerful noninvasive method for the study of local neuronal activation in the human spinal cord, which may be of clinical value for evaluating the effectiveness of interventions aimed at promoting recovery of function using electrical stimulation.

Phase Transfer of Nanoparticles Using an Amphiphilic Ionic Liquid.

The phase transfer of nanoparticles (NPs) from water to organic solvents by an amphiphilic room-temperature ionic liquid (IL) was reported. The geminal IL modified with Pluronic P123 stabilizes a variety of NPs of different size and nature, such as Pd, Au, Ag, and SiO2 NPs. Their phase transfer into a hydrophobic environment was realized by raising the temperature and adding salts (such as NaCl and KBr), both of which have a common effect of breaking the hydrogen bonds of the IL with H2O. A more straightforward method of using an organic solvent working as a hydrogen bond donor (such as butyl alcohol) was then proposed. In this case, NaCl was no longer required. To further apply this strategy to the organic solvents that are generally incapable of forming hydrogen bonds (e.g., toluene), a small quantity of benzoic acid was added to the organic phase. By forming hydrogen bonds from benzoic acid to the IL, an even more facile approach was provided. FT-IR confirmed the hydrogen bonding between them. The phase-transfer protocol does not rely on coordination bonding of ligands with a specific metal and is capable of the phase transfer of objects with large sizes and different natures. Thus, it has the potential for wide application.

[Correlation study of spinal canal and dural sac dimensions on MRI with therapy of lumbar disc herniation].

OBJECTIVE: To explore the value of spinal canal and dural sac dimensions for the treatment of lumbar disc herniation in MRI. METHODS: The clinical data of 144 patients with single-level lumbar disc herniation underwent nonsurgical or surgical treatment from January 2010 to December 2012 were retrospectively analyzed. There were 91 patients in the nonsurgical group, including 55 males and 36 females, ranging in age from 20 to 68 years old with an average of (43.37±12.48) years; and there were 53 patients in the surgical group, including 28 males and 25 females, ranging in age from 20 to 64 years old with an average of (42.98±12.95) years. JOA scores (29 scores) were used to evaluate clinical manifestation (including subjective symptoms, objective findings, limitation of daily activities and bladder function) and outcomes. The parameters related to spinal canal and dural sac dimensions (including spinal canal midsagittal diameter and available diameter, lateral recess width, spinal canal and dural sac cross-sectional area) in the initial axial T2-weighted MRI were measured, and odds ratio of available diameter to midsagittal diameter, odds ratio of lateral recess width to midsagittal diameter and area ratio of dural sac to spinal canal were calculated. Then, the differences of all parameters between two groups, and the correlations with initial JOA scores were analyzed. RESULTS: (1) All patients were followed up from 1 to 3 years with an average of 2.1 years. JOA scores before treatment were 16.27±2.96 in nonsurgical group and 12.64±3.30 in surgical group, there was statistically significant difference (t=6.319, P<0.01). At final follow-up time, there was no statistically significant difference in JOA scores (25.41±2.22 vs 25.76±2.29), improvement rate [(72.95±12.54)% vs (76.80±9.45)%], and the excellent and good rate (84.91% vs 78.02%) between two groups (P>0.05). But, the relapse rate of nonsurgical group was higher than surgical group (14.29% vs 5.67%). (2) Spinal canal midsagittal diameter and available diameter, lateral recess width, spinal canal and dural sac area, the ratio of available diameter to midsagittal diameter, and the ratio of lateral recess width to midsagittal diameter in surgical group were smaller than that of nonsurgical group, but the area ratio of dural sac to spinal canal was larger, and there were statistically significant differences between two groups (P<0.01). (3) The initial JOA scores showed significantly positive correlation with spinal canal midsagittal diameter and available diameter, lateral recess width, and canal and dural sac area (P<0.01); also presented positive correlation with the ratio of available diameter to midsagittal diameter and the ratio of lateral recess width to midsagittal diameter (P<0.05); but there was a significantly negative correlation between initial JOA scores and the area ratio of dural sac to spinal canal. CONCLUSION: Both nonsurgical and surgical treatment of lumbar disc herniation can obtain good effect, but the recurrence rate of non-surgical treatment is higher. Preoperative MRI measurement parameters of spinal canal and dural sac dimensions has certain value for the treatment selection of lumbar disc herniation, but further refinement and validation is still required.

Developing learning algorithms via optimized discretization of continuous dynamical systems.

Most of the existing numerical optimization methods are based upon a discretization of some ordinary differential equations. In order to solve some convex and smooth optimization problems coming from machine learning, in this paper, we develop efficient batch and online algorithms based on a new principle, i.e., the optimized discretization of continuous dynamical systems (ODCDSs). First, a batch learning projected gradient dynamical system with Lyapunov's stability and monotonic property is introduced, and its dynamical behavior guarantees the accuracy of discretization-based optimizer and applicability of line search strategy. Furthermore, under fair assumptions, a new online learning algorithm achieving regret O(√T) or O(logT) is obtained. By using the line search strategy, the proposed batch learning ODCDS exhibits insensitivity to the step sizes and faster decrease. With only a small number of line search steps, the proposed stochastic algorithm shows sufficient stability and approximate optimality. Experimental results demonstrate the correctness of our theoretical analysis and efficiency of our algorithms.

Room-temperature ferromagnetism and terahertz emission of Mn-doped InGaAs and GaAsSb nanowires.

Ferromagnetic Mn-doped In(0.05)Ga(0.95)As and GaAs(0.95)Sb(0.05) nanowires were synthesized by chemical vapor transport and their Mn concentration was about 2%. The Mn doped homogeneously into both the single-crystalline zinc blende InGaAs and GaAsSb without the formation of metal clusters. X-ray magnetic circular dichroism and magnetic moment measurements revealed their distinctive room-temperature ferromagnetic behaviors. While the incorporation of In enhances the ferromagnetism, that of Sb reduces it, which can be ascribed to the increase or decrease of the dopant-acceptor hybridization. These GaAs-based NWs exhibit an efficient terahertz emission at room temperature, due to a strong local field enhancement by coherent surface plasmons. The Mn doping significantly enhances the intensity and bandwidth of the terahertz emission, with an excellent correlation with their magnetization.

SSFSE sequence functional MRI of the human cervical spinal cord with complex finger tapping.

PURPOSE: Functional MR imaging of the human cervical spinal cord was carried out on volunteers during alternated rest and a complex finger tapping task, in order to detect image intensity changes arising from neuronal activity. METHODS: Functional MR imaging data using single-shot fast spin-echo sequence (SSFSE) with echo time 42.4 ms on a 1.5 T GE Clinical System were acquired in eight subjects performing a complex finger tapping task. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS: Intensity changes (5.5-7.6%) were correlated with the time course of stimulation and were consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. The activated regions localized to the ipsilateral side of the spinal cord in agreement with the neural anatomy. CONCLUSION: Functional MR imaging signals can be reliably detected with finger tapping activity in the human cervical spinal cord using a SSFSE sequence with 42.4 ms echo time. The anatomic location of neural activity correlates with the muscles used in the finger tapping task.

Functional MR imaging of the cervical spinal cord by use of 20Hz functional electrical stimulation to median nerve.

PURPOSE: Functional MR imaging of the human cervical spinal cord was carried out on volunteers by 20Hz functional electrical stimulation to median nerve, in order to detect signal changes arising concomitant to neuronal activity. METHODS: Functional MR imaging data were acquired in six subjects with single-shot fast spin-echo sequence (SSFSE) on a 1.5T GE Clinical System. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS: Activation correlated with the time course of stimulation was consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. Regions of the spinal cord associated with motor and pain response were observed by 20Hz functional electrical stimulation to the median nerve. CONCLUSION: The functional MR imaging signal can be detected in the human cervical spinal cord with functional electrical stimulation. Investigating the FES response in the spinal cord using the spinal fMRI will be helpful for the further discussion on the diagnosis and functional recovery to spinal cord diseases.

Interleukin-1 beta induction of neuron apoptosis depends on p38 mitogen-activated protein kinase activity after spinal cord injury.

AIM: Interleukin-1 beta (IL-1beta) has been implicated as an extracellular signal in the initiation of apoptosis in neurons and oligodendrocytes after spinal cord injury (SCI). To further characterize the apoptotic cascade initiated by IL-1beta after SCI, we examined the expression of IL-1beta, p38 mitogen-activated protein kinase (p38 MAPK) and caspase-3 after SCI, and further investigated whether p38 MAPK was involved in neuron apoptosis induced by IL-1beta. METHODS: Adult rats were given contusion SCI at the T-10 vertebrae level with a weight-drop impactor (10 g weight dropped 25.0 mm). The expression levels of IL-1beta, p38 MAPK and caspase-3 after SCI were assessed with Western blots, immunohistochemistry staining, and real time reverse transcription polymerase chain reactions (RT-PCR). Neuron apoptosis was assessed with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) method. RESULTS: Increased levels of IL-1beta and p38 MAPK were observed soon after injury, with a peak in expression levels within 6 h of injury. By 24 h after injury, caspase-3 expression was markedly increased in the injured spinal cord. TUNEL-positive cells were first observed in the lesioned area 6 h after SCI. The largest number of TUNEL-positive cells was observed at 24 h post-SCI. Intrathecal injection of the IL-1 receptor antagonist IL-1Ra significantly reduced expression of p38 MAPK and caspase-3, and reduced the number of TUNEL-positive cells. Moreover, intrathecal injection of an inhibitor of p38 MAPK, SB203580, also significantly reduced the expression of caspase-3, and reduced the number of TUNEL-positive cells in the injured spinal cord. CONCLUSION: The p38MAPK signaling pathway plays an important role in IL-1beta mediated induction of neuron apoptosis following SCI in rats.

Expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis.

AIM: To determine the expression of c-fos in gastric myenteric plexus and spinal cord of rats with cervical spondylosis and its clinical significance. METHODS: A cervical spondylosis model was established in rats by destroying the stability of cervical posterior column, and the cord segments C(4-6) and gastric antrum were collected 3, 4 and 5 mo after the operation. Rats with sham operation were used as controls. c-fos neuronal counter-staining was performed with an immunohistochemistry method. Every third sections from C(4-6) segments were drawn. The 10 most labeled c-fos-immunoreactive (Fos-IR) neurons were counted, and the average number was used for statistical analysis. The mean of Fos-IR neurons in myenteric plexus was calculated after counting Fos-IR neurons in 25 ganglia from each antral preparation, and expressed as a mean count per myenteric ganglion. RESULTS: There were a few c-fos-positive neurons in the cervical cord and antrum in the control group. There was an increased c-fos expression in model group 3, 4 and 5 mo after operation, whereas there was no significant increase in c-fos expression in the control group at 3, 4 and 5 mo. More importantly, there was a significant difference in c-fos expression between rats followed up for 3 mo and those for 5 mo in the model group (11.20+/-2.26 vs 27.68+/-4.36, P<0.05, for the cervical cord; and 11.3+/-2.3 vs 29.3+/-4.6, P<0.05, for the gastric antrum). There was no significant difference between rats followed up for 3 mo and those for 4 mo and between rats followed up for 4 mo and those for 5 mo in the model group. CONCLUSION: c-fos expression in gastric myenteric plexus was dramatically associated with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis. If this hypothesis is confirmed by further studies, functional gastrointestinal diseases such as functional dyspepsia and irritable bowel syndrome could be explained by neurogastroenterology.