New Calibrator with Points Distributed Conical Helically for Online Calibration of C-Arm.

To improve the accuracy of calibration of C-arm, and overcome the space limitation in surgery, we proposed a new calibrator for online calibration of C-arm. After the image rectification by a polynomial fitting-based global correction method, the C-arm was assumed as an ideal pinhole model. The relationships between two kinds of spatial calibration errors and the distribution of fiducial points were studied: the performance of FRE (Fiducial Registration Error) and TRE (Target Registration Error) were not consistent, but both were best at the 12 marked points; the TRE decreased with the increase of the uniformity of calibration points distribution, and with the decrease of the distance between the target point and the center of calibration points. A calibrator with 12 fiducial points conical helically distributed, which could be placed on the knee, was an attractive option. A total of 10 experiments on C-arm calibration accuracy were conducted and the mean value of mapping error was 0.41 mm. We designed an ACL reconstruction navigation system and carried out specimen experiments on 4 pairs of dry femur and tibia. The mean accuracy of navigation system was 0.85 mm, which is important to the tunnel positioning for ACL reconstruction.

A Normal Sensor Calibration Method Based on an Extended Kalman Filter for Robotic Drilling.

To enhance the perpendicularity accuracy in the robotic drilling system, a normal sensor calibration method is proposed to identify the errors of the zero point and laser beam direction of laser displacement sensors simultaneously. The procedure of normal adjustment of the robotic drilling system is introduced firstly. Next the measurement model of the zero point and laser beam direction on a datum plane is constructed based on the principle of the distance measurement for laser displacement sensors. An extended Kalman filter algorithm is used to identify the sensor errors. Then the surface normal measurement and attitude adjustments are presented to ensure that the axis of the drill bit coincides with the normal at drilling point. Finally, simulations are conducted to study the performance of the proposed calibration method and experiments are carried out on a robotic drilling system. The simulation and experimental results show that the perpendicularity of the hole is within 0.2°. They also demonstrate that the proposed calibration method has high accuracy of parameter identification and lays a basis for high-precision perpendicularity accuracy of drilling in the robotic drilling system.

Analysis and experimental kinematics of a skid-steering wheeled robot based on a laser scanner sensor.

Skid-steering mobile robots are widely used because of their simple mechanism and robustness. However, due to the complex wheel-ground interactions and the kinematic constraints, it is a challenge to understand the kinematics and dynamics of such a robotic platform. In this paper, we develop an analysis and experimental kinematic scheme for a skid-steering wheeled vehicle based-on a laser scanner sensor. The kinematics model is established based on the boundedness of the instantaneous centers of rotation (ICR) of treads on the 2D motion plane. The kinematic parameters (the ICR coefficient , the path curvature variable and robot speed ), including the effect of vehicle dynamics, are introduced to describe the kinematics model. Then, an exact but costly dynamic model is used and the simulation of this model's stationary response for the vehicle shows a qualitative relationship for the specified parameters and . Moreover, the parameters of the kinematic model are determined based-on a laser scanner localization experimental analysis method with a skid-steering robotic platform, Pioneer P3-AT. The relationship between the ICR coefficient and two physical factors is studied, i.e., the radius of the path curvature and the robot speed . An empirical function-based relationship between the ICR coefficient of the robot and the path parameters is derived. To validate the obtained results, it is empirically demonstrated that the proposed kinematics model significantly improves the dead-reckoning performance of this skid-steering robot.

Climber, mediator, and marathoner: narrative inquiry of career motivation changes of pre-service CSL teachers throughout teaching practicum.

Introduction: The growing global demand for foreign language learning contrasts sharply with the shortage of second language teachers. In Chinese as a second language (CSL) education, although the number of pre-service CSL teachers is increasing, few continue in the profession after completing their teacher education courses. Methods: To investigate the reasons behind this trend, this longitudinal narrative inquiry examined the career motivations of three participants during their teaching practicum. The study focused on identifying key narrative clues based on metaphors emerging from their narratives. Results: The research found that the participants' career motivations were influenced by their teaching practice and experienced various dynamic changes. Key motivational factors included self-efficacy and intrinsic self-fulfillment, with a notable influence from the unique cross-cultural motivation associated with second language teaching. Discussion: The study underscores the significant role of narratives and metaphors in understanding changes in teacher career motivations. It suggests that enhancing self-efficacy and intrinsic motivation, alongside recognizing cross-cultural motivations, could be crucial in addressing the retention issues among pre-service CSL teachers.

Robot-Assisted Needle Insertion for CT-Guided Puncture: Experimental Study with a Phantom and Animals.

PURPOSE: This study aimed to evaluate the accuracy and safety of robotic CT-guided needle insertion in phantom and animal experiments. MATERIALS AND METHODS: A robotic system was developed for CT-guided needle insertion. For the phantom experiment, a specially made phantom containing multiple spherical was used. 15 robotic and manual insertions were conducted, and the accuracy, time, number of needle insertions, and radiation dose were compared between the robotic and manual insertion using Student's t-test. For the animal experiment, 20 robotic needle insertions were attempted toward simulated pulmonary nodules in the swine lung. The accuracy and safety of robotic CT-guided needle insertions were evaluated. RESULTS: In the phantom experiment, the mean accuracies of manual and robotic insertion were 1.8 ± 0.3 mm and 1.9 ± 0.2 mm. The accuracy of robotic needle insertion had no significant difference with manual needle insertion, but the number of needle insertions and radiation dose of the robotic needle placement significantly decreased compared to manual needle placement. In the animal experiment, the mean accuracy of the robotic needle insertion was 3.8 ± 1.3 mm. The time for the whole needle insertion was 14.4 ± 4.8 min. The whole robotic needle insertions were safe and only one mild pneumothorax occurred. CONCLUSION: CT-guided robotic needle insertion showed accuracy comparable to manual needle insertion, but the number of needle insertions, confirmatory scans, and radiation exposure had been reduced significantly. In future, we will further apply the robotic system to clinical experiments.

Self-Calibrating Lanthanide Infinite Coordination Polymer Constructs Fluorescent Probes: A Sensitive Approach for Early Diagnosis of Hepatocellular Carcinoma and Environmental Analysis.

The development of a self-calibrating ratio fluorescence probe without the need for additional substrates is a major advancement in biosensing. In this study, at room temperature, a self-calibrating infinite coordination polymer (SSA-Tb-ATP ICPs) has been proposed by self-assembling adenosine triphosphate (ATP) with 5-sulfosalicylic acid (SSA) and Tb3+. Due to the antenna effect, SSA-Tb-ATP ICPs exhibited strong green fluorescence emission of Tb3+ (at 547 nm) and blue fluorescence emission of SSA (at 407 nm). This material offers several advantages over existing detection methods, including simplicity of synthesis and exceptional sensitivity. Our self-calibrating SSA-Tb-ATP ICPs demonstrated excellent performance in detecting alkaline phosphatase (ALP) and phosphate (Pi) in both serum and environmental samples with detection limits of 0.076 U/L and 0.025 µM, respectively. Moreover, we successfully employed the SSA-Tb-ATP ICPs to perform cellular imaging of ALP in both hepatocellular carcinoma cells (HepG2) and normal liver cells (LO2), representing a significant advancement in ALP detection and imaging. The simplicity of the synthesis and high sensitivity make this probe a promising tool for early diagnosis of hepatocellular carcinoma in clinical settings and environment analysis.

Autostereoscopic 3D Augmented Reality Navigation for Laparoscopic Surgery: A Preliminary Assessment.

OBJECTIVE: Since Augmented Reality (AR) and 3D visualization have proven to be of great significance to the safety and effectiveness of surgical outcomes, will autostereoscopic 3D AR without glasses bring new opportunities for surgical navigation of laparoscopic surgery? METHODS: We used the CPD-based deformation registration algorithm and the proposed virtual view generation algorithm, realizing a deformable autostereoscopic 3D AR navigation framework for laparoscopic surgery. The depth perception and user experience of the 3D AR navigation were evaluated compared with the 2D AR display using an in-vitro porcine heart and offline clinical partial nephrectomy laparoscopic images. RESULTS: The autostereoscopic 3D AR allowed participants to have a more consistent spatial perception as well as a shorter measuring time than 2D AR with significant difference of p < 0.05. It can also improve relative depth perception for smaller distance separation of objects < = 3.28 mm. However, the autostereoscopic 3D AR perceived a worse experience compared to 2D AR in the user experience. CONCLUSION: Autostereoscopic 3D AR shows a more efficient and robust sense of spatial scale than 2D AR with better potential to shorten the operating time and improve surgical outcomes than 2D AR, but image blur and distortion are issues that must be solved to improve the perception effect. High precise registration and high fluency visualization requirements could make autostereoscopic 3D AR navigation for soft tissue more challenging. SIGNIFICANCE: Our work lays a theoretical foundation for the further development of laparoscopic surgical navigation.

An accurately controlled antagonistic shape memory alloy actuator with self-sensing.

With the progress of miniaturization, shape memory alloy (SMA) actuators exhibit high energy density, self-sensing ability and ease of fabrication, which make them well suited for practical applications. This paper presents a self-sensing controlled actuator drive that was designed using antagonistic pairs of SMA wires. Under a certain pre-strain and duty cycle, the stress between two wires becomes constant. Meanwhile, the strain to resistance curve can minimize the hysteresis gap between the heating and the cooling paths. The curves of both wires are then modeled by fitting polynomials such that the measured resistance can be used directly to determine the difference between the testing values and the target strain. The hysteresis model of strains to duty cycle difference has been used as compensation. Accurate control is demonstrated through step response and sinusoidal tracking. The experimental results show that, under a combination control program, the root-mean-square error can be reduced to 1.093%. The limited bandwidth of the frequency is estimated to be 0.15 Hz. Two sets of instruments with three degrees of freedom are illustrated to show how this type actuator could be potentially implemented.

[Percutaneous pelvic fracture stabilization using CT-based 3D navigation software combined with targeting mechanical arm: a cadaver model trial].

OBJECTIVES: To investigate a new targeting mechanical arm for CT-based navigated percutaneous fixation of pelvic fractures, and to evaluate the safety and efficiency of the procedures. METHODS: Using CT-based 3D navigation software combined with targeting mechanical arm, percutaneous insertion of pelvic models (3 dry human cadaver pelvic skeletons and 5 plastic Sybone pelvic models) were performed, 8 pelvic models allowed percutaneous cannulated screw insertion of both S-I joint (2 S-I screws placement for each side, total 32 screws in this experiment) and both superior ramus (1 ramus medullary screw placement for each side, total 16 screws in this experiment). Percutaneous insertion of pelvic models (4 dry human cadaver pelvic skeletons and 4 plastic Sybone pelvic models, 1 S-I screws and 1 ramus medullary scre placement for each side, 32 screws in this experiment) were performed using fluoro-navigation system (Stryker, USA). Time necessary for every screw insertion were recorded. Accuracy of screw placement was assessed using C-arm imaging and direct eyes inspecting. The time and accuracy of the two methods were compared. RESULTS: The time required for the CT-based 3D navigation procedure (3.6 ± 1.2) min was significantly less than using the targeting mechanical arm compared to drilling freehand with navigation (9.1 ± 0.8) min (t = 2.50, P < 0.01). There was no significant difference in accuracy between the two methods. CONCLUSION: CT-based 3D navigation software combined with targeting mechanical arm should be potential to apply percutaneous sacroiliac screwing for pelvic fractures with more accurate and more reliable.

The roles of motivation, anxiety and learning strategies in online Chinese learning among Thai learners of Chinese as a foreign language.

The impact of motivation, anxiety and learning strategies on the achievement of foreign language proficiency has been widely acknowledged in the context of traditional offline classroom settings. However, this issue has not been extensively documented in relation to online learning, which has become the predominant form of language learning during the period of the COVID-19 pandemic. The current study was conducted to investigate the relative prediction of motivation, anxiety and learning strategies for second language achievement among 90 Thai adult learners of Chinese as a foreign language (CFL) who took online Chinese courses. The participants completed a questionnaire dealing with motivation, anxiety, learning strategies, and their Chinese proficiency was measured by self-report and a Chinese vocabulary size test. A series of hierarchical regression analyses revealed two major findings. First, anxiety emerged as the most stable factor for the participants' CFL achievement, followed by learning strategies and motivation. Second, motivation, anxiety and learning strategies only significantly predicted the participants' self-rated Chinese language proficiency, but not their performance on the Chinese vocabulary size test. The overall results indicate the relative importance of motivation, anxiety and learning strategies to Chinese language learning in the online environment and suggest different measures of CFL achievement may lead to different research findings. The general findings were of theoretical and pedagogical significance for understanding and addressing individual differences factors in online language learning.

Robotic system with programmable motion constraint for transurethral resection.

PURPOSE: We propose a tele-operated transurethral robotic system with programmable motion constraint for tissue resection. METHODS: The system consists of a surgeon console with an interaction device, a 7-degree-of-freedom manipulator, and a surgical end-effector. The surgical end-effector holds a resectoscope with a motor driven mechanism to perform electrocautery. Instrumental motion with remote center-of-motion (RCM) constraint is important for transurethral procedures since the damage to the healthy structures can be minimized. A screw theory-based programmable RCM generator is proposed to map the inputs of the interaction device to the RCM manifold in the manipulator space. To achieve smooth real-time manipulator following control with RCM constraint, an online trajectory planner is presented. RESULTS: Experiments were performed to evaluate the motion precision and accuracy. The results show that both the RCM precision and accuracy were less than 1 mm. Ex-vivo experiments of robotic resection of soft tissue were also carried out. The results show that our robotic system could achieve instrumental manipulation and delicate cutting under the real-time control of a surgeon. CONCLUSIONS: Our robotic system could assist surgeons in performing transurethral procedures in a remote manner with potential advantages of being accurate, less laborious and clean.

Transfer Learning for Nonrigid 2D/3D Cardiovascular Images Registration.

Cardiovascular image registration is an essential approach to combine the advantages of preoperative 3D computed tomography angiograph (CTA) images and intraoperative 2D X-ray/digital subtraction angiography (DSA) images together in minimally invasive vascular interventional surgery (MIVI). Recent studies have shown that convolutional neural network (CNN) regression model can be used to register these two modality vascular images with fast speed and satisfactory accuracy. However, CNN regression model trained by tens of thousands of images of one patient is often unable to be applied to another patient due to the large difference and deformation of vascular structure in different patients. To overcome this challenge, we evaluate the ability of transfer learning (TL) for the registration of 2D/3D deformable cardiovascular images. Frozen weights in the convolutional layers were optimized to find the best common feature extractors for TL. After TL, the training data set size was reduced to 200 for a randomly selected patient to get accurate registration results. We compared the effectiveness of our proposed nonrigid registration model after TL with not only that without TL but also some traditional intensity-based methods to evaluate that our nonrigid model after TL performs better on deformable cardiovascular image registration.

A robotic system for spine surgery positioning and pedicle screw placement.

BACKGROUND: In recent years, surgeons have explored minimally invasive methods of percutaneous pedicle screw implantation which can effectively reduce human injuries. This article presents an accurate and efficient positioning method and robot system for percutaneous needle placement under c-arm fluoroscopy. METHODS: A simple five degree of freedom (DOF) robot with a unique end-effector is designed to perform perspective calibration and image space registration. The principle of pedicle standard axis positioning is adopted to make the axis of the pedicle overlap with the x-ray axis of c-arm. RESULTS: Then the clinical operation is carried out to verify the clinical feasibility of the designed robot and positioning method. The experimental results show that a total of 26 pedicle screws were accurately implanted. The accuracy of Grade A is 96.15%. The positioning time of a single guide pin is about 154.77 s, and three x-ray films need to be taken on average. CONCLUSIONS: The positioning accuracy is increased by using the present method. In addition, this method is simple in operation, short in operation time, low in X-ray exposure.

Assessment and application of the coherent point drift algorithm to augmented reality surgical navigation for laparoscopic partial nephrectomy.

PURPOSE: The surface-based registration approach to laparoscopic augmented reality (AR) has clear advantages. Nonrigid point-set registration paves the way for surface-based registration. Among current non-rigid point set registration methods, the coherent point drift (CPD) algorithm is rarely used because of two challenges: (1) volumetric deformation is difficult to predict, and (2) registration from intraoperative visible tissue surface to whole anatomical preoperative model is a "part-to-whole" registration that CPD cannot be applied directly to. We preliminarily applied CPD on surgical navigation for laparoscopic partial nephrectomy (LPN). However, it introduces normalization errors and lacks navigation robustness. This paper presents important advances for more effectively applying CPD to LPN surgical navigation while attempting to quantitatively evaluate the accuracy of CPD-based surgical navigation. METHODS: First, an optimized volumetric deformation (Op-VD) algorithm is proposed to achieve accurate prediction of volume deformation. Then, a projection-based partial selection method is presented to conveniently and robustly apply the CPD to LPN surgical navigation. Finally, kidneys with different deformations in vitro, phantom and in vivo experiments are performed to evaluate the accuracy and effectiveness of our approach. RESULTS: The average root-mean-square error of volume deformation was refined to 0.84 mm. The mean target registration error (TRE) of the surface and inside markers in the in vitro experiments decreased to 1.51 mm and 1.29 mm, respectively. The robustness and precision of CPD-based navigation were validated in phantom and in vivo experiments, and the mean navigation TRE of the phantom experiments was found to be [Formula: see text] mm. CONCLUSION: Accurate volumetric deformation and robust navigation results can be achieved in AR navigation of LPN by using surface-based registration with CPD. Evaluation results demonstrate the effectiveness of our proposed methods while showing the clinical application potential of CPD. This work has important guiding significance for the application of the CPD in laparoscopic AR.

Octopus Arm-Inspired Tapered Soft Actuators with Suckers for Improved Grasping.

Octopuses can employ their tapered arms to catch prey of all shapes and sizes due to their dexterity, flexibility, and gripping power. Intrigued by variability in arm taper angle between different octopus species, we explored the utility of designing soft actuators exhibiting a distinctive conical geometry, compared with more traditional cylindrical forms. We find that these octopus-inspired conical-shaped actuators exhibit a wide range of bending curvatures that can be tuned by simply altering their taper angle and they also demonstrate greater flexibility compared with their cylindrical counterparts. The taper angle and bending curvature are inversely related, whereas taper angle and applied bending force are directly related. To further expand the functionality of our soft actuators, we incorporated vacuum-actuated suckers into the actuators for the production of a fully integrated octopus arm-inspired gripper. Notably, our results reveal that because of their enhanced flexibility, these tapered actuators with suckers have better gripping power than their cylindrical-shaped counterparts and require significantly larger forces to be detached from both flat and curved surfaces. Finally, we show that by choosing appropriate taper angles, our tapered actuators with suckers can grip, move, and place a remarkably wide range of objects with flat, nonplanar, smooth, or rough surfaces, as well as retrieve objects through narrow openings. The results from this study not only provide new design insights into the creation of next-generation soft actuators for gripping a wide range of morphologically diverse objects but also contribute to our understanding of the functional significance of arm taper angle variability across octopus species.

Preparation of Highly Active Monometallic Rhenium Catalysts for Selective Synthesis of 1,4-Butanediol from 1,4-Anhydroerythritol.

1,4-Butanediol can be produced from 1,4-anhydroerythritol through the co-catalysis of monometallic mixed catalysts (ReOx /CeO2 +ReOx /C) in the one-pot reduction with H2 . The highest yield of 1,4-butanediol was over 80 %, which is similar to the value obtained over ReOx -Au/CeO2 +ReOx /C catalysts. Mixed catalysts of CeO2 +ReOx /C showed almost the same performance, giving 89 % yield of 1,4-butanediol. The reactivity trends of possible intermediates suggest that the reaction mechanism over ReOx /CeO2 +ReOx /C is similar to that over ReOx -Au/CeO2 +ReOx /C: deoxydehydration (DODH) of 1,4-anhydroerythritol to 2,5-dihydrofuran over ReOx species on the CeO2 support with the promotion of H2 activation by ReOx /C, isomerization of 2,5-dihydrofuran to 2,3-dihydrofuran catalyzed by ReOx on the C support, hydration of 2,3-dihydrofuran catalyzed by C, and hydrogenation to 1,4-butanediol catalyzed by ReOx /C. The reaction order of conversion of 1,4-anhydroerythritol with respect to H2 pressure is almost zero and this indicates that the rate-determining step is the formation of 2,5-dihydrofuran from the coordinated substrate with reduced Re in the DODH step. The activity of ReOx /CeO2 +ReOx /C is higher than that of ReOx -Au/CeO2 +ReOx /C, which is probably related to the reducibility of ReOx /C and the mobility of the Re species between the supports. High-valent Re species such as Re7+ on the CeO2 and C supports are mobile in the solvent; however, low-valent Re species, including metallic Re species, have much lower mobility. Metallic Re and cationic low-valent Re species with high reducibility and low mobility can be present on the carbon support as a trigger for H2 activation and promoter of the reduction of Re species on CeO2 . The presence of noble metals such as Au can enhance the reducibility through the activation of H2 molecules on the noble metal and the formation of spilt-over hydrogen over noble metal/CeO2 , as indicated by H2 temperature-programmed reduction. The higher reducibility of ReOx -Au/CeO2 lowers the DODH activity of ReOx -Au/CeO2 +ReOx /C in comparison with ReOx /CeO2 +ReOx /C by restricting the movement of Re species from C to CeO2 .

An Opposite-Bending-and-Extension Soft Robotic Manipulator for Delicate Grasping in Shallow Water.

Collecting seafood animals (such as sea cucumbers, sea echini, scallops, etc.) cultivated in shallow water (water depth: ~30 m) is a profitable and an emerging field that requires robotics for replacing human divers. Soft robotics have several promising features (e.g., safe contact with the objects, lightweight, etc.) for performing such a task. In this paper, we implement a soft manipulator with an opposite-bending-and-extension structure. A simple and rapid inverse kinematics method is proposed to control the spatial location and trajectory of the underwater soft manipulator's end effector. We introduce the actuation hardware of the prototype, and then characterize the trajectory and workspace. We find that the prototype can well track fundamental trajectories such as a line and an arc. Finally, we construct a small underwater robot and demonstrate that the underwater soft manipulator successfully collects multiple irregular shaped seafood animals of different sizes and stiffness at the bottom of the natural oceanic environment (water depth: ~10 m).

A markerless automatic deformable registration framework for augmented reality navigation of laparoscopy partial nephrectomy.

Purpose Video see-through augmented reality (VST-AR) navigation for laparoscopic partial nephrectomy (LPN) can enhance intraoperative perception of surgeons by visualizing surgical targets and critical structures of the kidney tissue. Image registration is the main challenge in the procedure. Existing registration methods in laparoscopic navigation systems suffer from limitations such as manual alignment, invasive external marker fixation, relying on external tracking devices with bulky tracking sensors and lack of deformation compensation. To address these issues, we present a markerless automatic deformable registration framework for LPN VST-AR navigation. METHOD: Dense stereo matching and 3D reconstruction, automatic segmentation and surface stitching are combined to obtain a larger dense intraoperative point cloud of the renal surface. A coarse-to-fine deformable registration is performed to achieve a precise automatic registration between the intraoperative point cloud and the preoperative model using the iterative closest point algorithm followed by the coherent point drift algorithm. Kidney phantom experiments and in vivo experiments were performed to evaluate the accuracy and effectiveness of our approach. RESULTS: The average segmentation accuracy rate of the automatic segmentation was 94.9%. The mean target registration error of the phantom experiments was found to be 1.28 ± 0.68 mm (root mean square error). In vivo experiments showed that tumor location was identified successfully by superimposing the tumor model on the laparoscopic view. CONCLUSION: Experimental results have demonstrated that the proposed framework could accurately overlay comprehensive preoperative models on deformable soft organs automatically in a manner of VST-AR without using extra intraoperative imaging modalities and external tracking devices, as well as its potential clinical use.

Intensity-based 2D-3D registration for an ACL reconstruction navigation system.

To improve the positioning accuracy of tunnels for anterior cruciate ligament (ACL) reconstruction, we proposed an intensity-based 2D-3D registration method for an ACL reconstruction navigation system. Methods for digitally reconstructed radiograph (DRR) generation, similarity measurement, and optimization are crucial to 2D-3D registration. We evaluated the accuracy, success rate, and processing time of different methods: (a) ray-casting and splating were compared for DRR generation; (b) normalized mutual information (NMI), Mattes mutual information (MMI), and Spearman's rank correlation coefficient (SRC) were assessed for similarity between registrations; and (c) gradient descent (GD) and downhill simplex (DS) were compared for optimization. The combination of splating, SRC, and GD provided the best composite performance and was applied in an augmented reality (AR) ACL reconstruction navigation system. The accuracy of the navigation system could fulfill the clinical needs of ACL reconstruction, with an end pose error of 2.50 mm and an angle error of 2.74°.

Application of a robotic telemanipulation system in stereotactic surgery.

To assess the clinical usefulness, accuracy, and safety of telemanipulation for frameless stereotactic surgery using the CAS-BH5 robot system, we prospectively evaluated 10 patients (age: 5-79 years; mean: 44 years) who underwent telemanipulation frameless stereotactic operations from September to December 2005. The CAS-BH5 robot system consists of three main parts: a planning subsystem, a surgical localization subsystem, and a telemanipulation subsystem. Specifically, CAS-BH5 is capable of network communication, video transmission, graphic simulation and human-machine interaction, and thus facilitates remote planning and transmission of neuronavigation data, monitoring and manipulating. Telemanipulation was performed via a digital data network with a speed of 2,000 kilobytes per second by a neurosurgeon in Beijing while the patients were located in Yan'an, 1,300 km away. Remote fiducial registration was performed with a mean accuracy of 1.05 mm and the standard difference between the planned and actual trajectory was 0.13 mm. The mean time from fiducial registration to closure was 30.2 +/- 1.66 min. At 12-month follow-up, 90% of patients had improved neurologically. There were no complications. This preliminary data indicates that telemanipulation in frameless stereotactic surgeries is feasible, reliable and safe. In the future, we believe that telemanipulation will facilitate collaboration between surgeons, enhance training, allow for sharing of resources, and have wide applications in the field of neurosurgery.