The application of this robotic technique was approved by the ethics committee of the Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, and it complies with the Helsinki Declaration of 1975, as revised in 2013.
1. Preoperative planning
<ol>
	<li>Fix the cadaveric pelves in the supine position using a fluoroscopic plate base (see Table of Materials) by inserting two Schanz pins through the femur. In the supine position, place both the posterior superior iliac spines simultaneously on the plank and the lumbar vertebrae parallel to the floor. 
	NOTE: The donated cadavers were embalmed by the Department of Anatomy and Research, Tongji Medical College, Huazhong University of Science and Technology. The pelvic specimens were obtained by transection at the level of the lumbar 5 vertebrae and below the lesser trochanter of the femur. The organs in the pelvic cavity were removed. The muscles, joint capsules, and ligamentous structures were left intact.</li>
	<li>Acquire images of the pelves from the upper edge of the L5 vertebrae to the distal femoral trochanter using a spiral CT (see Table of Materials). Process the computed tomography (CT) images of all the cadavers using the workstation, and store them in the DICOM format. 
	NOTE: CT parameters: 0.5 mm slice thickness, 63 mA current, 140 kV voltage.</li>
	<li>Import the CT scan data into the preoperative planning software (see Table of Materials) of this system in the DICOM format to obtain axial, coronal, and sagittal images of the pelvis. 
	NOTE: The DICOM files contain the information from the CT scan, and the reconstructed image can be obtained by automatic import.</li>
	<li>Create a cylinder using the MedCAD module of the software, and define the size of the cylinder by typing in the diameter and length. Place it into the S1 or S2 vertebral body, and adjust the orientation of the cylinder midline on the axial and coronal images. Check the relationship between the edge of the cylinder and the cortical bone in each image. 
	&#8203;NOTE: The cylinder entirely within the cancellous bone (excluding contact with the cortical bone) is considered to have a corresponding screw channel in S1 or S2. The length of the middle line of the cylinder is the length of the screw.</li>
</ol>
2. Surgical setting
<ol>
	<li>Fix the pelvis on the fluoroscopic operating table in the supine position (Figure 1).</li>
	<li>Place the Robot (see Table of Materials) on the ipsilateral side at 45&#176; to the operating table with the C-arm perpendicular to the operating table on the contralateral side. The monitor of the C-arm should face the operating room to enable the surgeon to observe it (Figure 1).</li>
	<li>Place the workstation of the MSOPGS and Slave Manipulator outside the operating room. The surgeon should be able to observe the surgical field and the C-arm monitor while teleoperating with the Slave-Manipulator (Figure 1).</li>
</ol>
3. Surgical procedure
NOTE: After the system is started and inspected, the manipulator is automatically deployed to the working state.
<ol>
	<li>Fix the grid position maker with adhesive tape on the ipsilateral side. Select the target area by a grid position marker on the true lateral view of the sacrum. Ensure that the manual traction mode on the console is selected and started. Drag the robotic arm to the general area of the S1 or S2 transiliac-transsacral screw entry point (Figure 3A, B). 
	NOTE: The target area is enclosed by the anterior border of the sacrum, the sacral nerve canal, and the spinal canal.</li>
	<li>Visualize the true lateral view of the sacrum, operate the Master Manipulator, and adjust the tip of the distal sleeve to be located in the guidewire entry area in the Master-Slave operation mode (Figure 3C).</li>
	<li>After selecting the RCM mode, continue the C-arm fluoroscopy for the lateral sacral view. Adjust the center of the guidewire sleeve into concentric circles to be consistent with the screw channel (Figure 3D).</li>
	<li>Lock the robotic arm, and insert a guidewire (2.5 mm K-wire, see Table of Materials) through the contralateral ilium using an electric drill. Then, remove the Robot in Manual traction mode (Figure 3E). 
	NOTE: No fluoroscopy should be performed during this step.</li>
	<li>Turn the C-arm to the inlet and outlet angles (different pelves have different angles) to determine whether the guidewire has broken through or contacted the anterior and posterior sacral cortex and the sacral nerve canal (Figure 3F, G).</li>
	<li>Insert a 7.3 mm semi-threaded screw (see Table of Materials) along the guidewire to the contralateral iliac cortex.</li>
	<li>Assess the screw position in the pelvic inlet and outlet view and the lateral view (Figure 4).</li>
</ol>
4. Postoperative assessment
<ol>
	<li>Perform steps 1.2-1.3. 
	NOTE: CT parameters: 0.5 mm slice thickness, 63 mA current, and 140 kV voltage.</li>
	<li>Check the screw position in each axial, coronal, and sagittal image. 
	NOTE: The screw positions were assessed using Gras&#39;s method. Specifically, screws in the cancellous bone are Grade I, screws in contact with the cortical bone are Grade II, and screws that penetrate the cortical bone are Grade III. Grade III represents screw misplacement and indicates a risk of vascular and nerve injury13.</li>
</ol>

<ol>
	<li>Bargar, W. L., Bauer, A., B&#246;rner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primary+and+revision+total+hip+replacement+using+the+Robodoc+system.">Primary and revision total hip replacement using the Robodoc system.</a> Clinical Orthopaedics and Related Research. (354), 82-91 (1998).</li><li>Jacofsky, D. J., Allen, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotics+in+arthroplasty:+A+comprehensive+review.">Robotics in arthroplasty: A comprehensive review.</a> Journal of Arthroplasty. 31 (10), 2353-2363 (2016).</li><li>Perfetti, D. C., Kisinde, S., Rogers-LaVanne, M. P., Satin, A. M., Lieberman, I. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotic+spine+surgery:+Past,+present+and+future.">Robotic spine surgery: Past, present and future.</a> Spine. 47 (13), 909-921 (2022).</li><li>Long, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+study+of+percutaneous+sacroiliac+screw+with+or+without+TiRobot+assistance+for+treating+pelvic+posterior+ring+fractures.">Comparative study of percutaneous sacroiliac screw with or without TiRobot assistance for treating pelvic posterior ring fractures.</a> Orthopaedic Surgery. 11 (3), 386-396 (2019).</li><li>Duan, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robot-assisted+percutaneous+cannulated+screw+fixation+of+femoral+neck+fractures:+Preliminary+clinical+results.">Robot-assisted percutaneous cannulated screw fixation of femoral neck fractures: Preliminary clinical results.</a> Orthopaedic Surgery. 11 (1), 34-41 (2019).</li><li>Lei, H., Sheng, L., Manyi, W., Junqiang, W., Wenyong, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+biplanar+robot+navigation+system+for+the+distal+locking+of+intramedullary+nails.">A biplanar robot navigation system for the distal locking of intramedullary nails.</a> International Journal of Medical Robotics and Computer Assisted Surgery. 6 (1), 61-65 (2010).</li><li>Oszwald, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotized+access+to+the+medullary+cavity+for+intramedullary+nailing+of+the+femur.">Robotized access to the medullary cavity for intramedullary nailing of the femur.</a> Technology and Health Care. 18 (3), 173-180 (2010).</li><li>Hung, S. S., Lee, M. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+assessment+of+a+surgical+robot+for+reduction+of+lower+limb+fractures.">Functional assessment of a surgical robot for reduction of lower limb fractures.</a> International Journal of Medical Robotics and Computer Assisted Surgery. 6 (4), 413-421 (2010).</li><li>Dagnino, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Image-guided+surgical+robotic+system+for+percutaneous+reduction+of+joint+fractures.">Image-guided surgical robotic system for percutaneous reduction of joint fractures.</a> Annual Review of Biomedical Engineering. 45 (11), 2648-2662 (2017).</li><li>Garcia, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trauma+Pod:+A+semi-automated+telerobotic+surgical+system.">Trauma Pod: A semi-automated telerobotic surgical system.</a> International Journal of Medical Robotics and Computer Assisted Surgery. 5 (2), 136-146 (2009).</li><li>Gaensslen, A., M&#252;ller, M., Nerlich, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Acetabular Fractures: Diagnosis, Indications, Treatment Strategies. , (2017).</li><li>LBR Med: A collaborative robot for medical applications. KUKA Available from: <a target="_blank" href="https://www.kuka.com/en-cn/industries/health-care/kuka-medical-robotics/lbr-med">https://www.kuka.com/en-cn/industries/health-care/kuka-medical-robotics/lbr-med</a> (2023)</li><li>Gras, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2D-fluoroscopic+navigated+percutaneous+screw+fixation+of+pelvic+ring+injuries--A+case+series.">2D-fluoroscopic navigated percutaneous screw fixation of pelvic ring injuries--A case series.</a> BMC Musculoskeletal Disorders. 11, 153 (2010).</li><li>Innocenti, B., Bori, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotics+in+orthopaedic+surgery:+Why,+what+and+how.">Robotics in orthopaedic surgery: Why, what and how.</a> Archives of Orthopaedic and Trauma Surgery. 141 (12), 2035-2042 (2021).</li><li>Chen, A. F., Kazarian, G. S., Jessop, G. 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J., Hundersmarck, D., Smeeing, D. P. J., vander Velde, D., Weaver, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robot-assisted+fracture+fixation+in+orthopaedic+trauma+surgery:+A+systematic+review.">Robot-assisted fracture fixation in orthopaedic trauma surgery: A systematic review.</a> OTA International. 4 (4), 153 (2021).</li><li>Wang, J. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+sacroiliac+screw+placement:+A+prospective+randomized+comparison+of+robot-assisted+navigation+procedures+with+a+conventional+technique.">Percutaneous sacroiliac screw placement: A prospective randomized comparison of robot-assisted navigation procedures with a conventional technique.</a> Chinese Medical Journal. 130 (21), 2527-2534 (2017).</li><li>Zhu, Z. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TiRobot-assisted+percutaneous+cannulated+screw+fixation+in+the+treatment+of+femoral+neck+fractures:+A+minimum+2-year+follow-up+of+50+patients.">TiRobot-assisted percutaneous cannulated screw fixation in the treatment of femoral neck fractures: A minimum 2-year follow-up of 50 patients.</a> Orthopaedic Surgery. 13 (1), 244-252 (2021).</li><li>Gardner, M. J., Routt, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transiliac-transsacral+screws+for+posterior+pelvic+stabilization.">Transiliac-transsacral screws for posterior pelvic stabilization.</a> Journal of Orthopaedic Trauma. 25 (6), 378-384 (2011).</li><li>Verhey, J. T., Haglin, J. M., Verhey, E. M., Hartigan, D. 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The authors declare that they have no competing interests.

Regardless of the type of Robot, the core application of robots in orthopedics provides an advanced tool for surgeons to improve the accuracy of surgery. However, the emergence of surgical robots is not a replacement for doctors. Surgeons performing robotic surgery may or may not be in the operating room. Surgical robots generally include a computer control system, a robotic arm responsible for the operation, and a navigation system responsible for tracking. There are three categories of robot systems depending on how th...

The first robotic application utilized in orthopedic surgery was the ROBODOC system employed in 19921. Since then, robot-assisted surgical systems have rapidly developed. Robot-assisted surgery improves arthroplasty by enhancing the surgeon&#39;s ability to restore the alignment of the limb and the physiological kinematics of the joint2. In spinal surgery, the placement of pedicle screws using a robot is safe and accurate; it also reduces the surgeon&#39;s radiation exposure3. However, studies on robot-assisted surgery have been limited owing to the heterogeneity of traumatic orthopedic diseases. The existing research on robotic surgery for orthopedic trauma mainly focuses on robot-assisted sacroiliac joint screws and pubic-screw fixation of pelvic ring fractures4, cannulated screw fixation of the femoral neck5, entry point and distal locking bolts in intramedullary nailing6,7, percutaneous fracture reduction8,9, and the treatment of critically wounded patients in the military field10.
The percutaneous screw technique can be performed using 2D and 3D navigation support. The sacroiliac, anterior column, posterior column, supraacetabular, and magic screws are the most common percutaneous techniques for pelvic and acetabular factures11. The percutaneous transiliac-transsacral screw technique remains challenging for surgeons. An understanding of pelvic anatomy and X-ray fluoroscopy, accurate positioning, and long-term hand stability are required for this procedure. The teleoperated robotic system can meet these requirements well. This study utilizes a teleoperated robotic system to complete percutaneous transiliac-transsacral screw fixation for pelvic ring fractures. The details and workflow of this protocol are presented below.
Robotic system 
The Master-Slave Orthopaedic Positioning and Guidance System (MSOPGS) is mainly composed of three parts: the surgical Robot (Slave Manipulator) with seven degrees of freedom (DOF), the Master Manipulator with force feedback, and the console. The system has four operating modes: manual traction, master-slave operation, remote center of motion (ROM), and emergency. Figure 1 shows the MSOPPGS; its main components are briefly described below.
The surgical robot (see Table of Materials) is a seven DOF manipulator that is pre-certified for integration into medical products12. The Robot has force-feedback sensors that can detect changes in force. The robotic arm can be operated manually or remotely. A torque sensor is installed at the tip and mapped to the &#34;Master Manipulator,&#34; enabling real-time force feedback. The maximum load on the robotic arm is sufficient to resist soft tissue forces and reduce the fluttering of the surgical instruments. The Robot is attached to a mobile platform to acquire an operational workplace and ensure stability. The base is connected to the &#34;Master Manipulator&#34; and the operative system and can process instructions from the operative system.
The &#34;Master Manipulator&#34; is designed for healthcare industries to precisely control the Robot. This device offers seven active DOF, including high-precision force-feedback grasping capabilities. Its end effector covers the natural range of motion of the human hand. An incremental control strategy is used to achieve intuitive control of the robotic arm.
The operative system provides four methods for controlling the robotic arm: manual traction, master-slave operation mode, remote centre of motion (RCM), and emergency. The operative system links the surgeon and Robot and provides safety alarms. The manual traction mode allows the manipulator to be dragged freely within a specific working range. The Robot is automatically locked after being stopped for 5 s. In the master-slave mode, the surgeon can use the &#34;Master Manipulator&#34; to control the movement of the robotic arm. The RCM mode permits the surgical instrument to pivot around the end of the instrument. The RCM mode is best suited to reorientation on the axial fluoroscopy view of the channel, such as the radiographic teardrop sign of the supraacetabular channel and the true sacral view of the transiliac-transsacral osseous pathway. The manipulator can be used for emergency braking at any position. Figure 2 shows the workflow of the system.

<table><tbody><tr><td>160-slice CT</td><td>United Imaging Healthcare Surgical Technology Co. Ltd</td><td>uCT780</td><td>Acquire the prescise image and DICOM data</td></tr><tr><td>Electric bone drill</td><td>YUTONG Medical</td><td>None</td><td>Power system</td></tr><tr><td>Fluoroscopic plate base</td><td>None</td><td>None</td><td>Fix the cadaveric pelves to operating table</td></tr><tr><td>K-wire</td><td>None</td><td>2.5mm</td><td>Guidewire</td></tr><tr><td>Master-Slave Orthopaedic Positioning and Guidance System</td><td>United Imaging Healthcare Surgical Technology Co. Ltd</td><td>None</td><td>A teleoperated robotic system that positions screws for orthopaedic surgery</td></tr><tr><td>Mimics Innovation Suite</td><td>Materialise</td><td>Mimics Medical 21</td><td>Preoperative planning software &amp;nbsp;&amp;nbsp;</td></tr><tr><td>Mobile C-arm</td><td>United Imaging Healthcare Surgical Technology Co. Ltd</td><td>uMC560i</td><td>Low Dose CMOS Mobile C-arm</td></tr><tr><td>Operating table&amp;nbsp;</td><td>KELING</td><td>DL&amp;middot;C-I</td><td>Fluoroscopic surgical table</td></tr><tr><td>Schanz pins</td><td>Tianjin ZhengTian Medical Instrument Co.,Ltd.</td><td>5.0mm</td><td>Fix the cadaveric pelves</td></tr><tr><td>Semi-threaded screw</td><td>Tianjin ZhengTian Medical Instrument Co.,Ltd.</td><td>7.3mm</td><td>Transiliac-Transsacral Screw</td></tr><tr><td>Seven DOF manipulator</td><td>KUKA, Germany</td><td>LBR Med 7 R800</td><td>Device for performing surgical operations</td></tr></tbody></table>

a teleoperated robotic system-assisted percutaneous transiliac-transsacral screw fixation technique

Transiliac-transsacral screw fixation is challenging in clinical practice as the screws need to break through six layers of cortical bone. Transiliac-transsacral screws provide a longer lever arm to withstand the perpendicular vertical shear forces. However, the screw channel is so long that a minor discrepancy can lead to iatrogenic neurovascular injuries. The development of medical robots has improved the precision of surgery. The present protocol describes how to use a new teleoperated robotic system to execute transiliac-transacral screw fixation. The Robot was operated remotely to position the entry point and adjust the orientation of the sleeve. The screw positions were evaluated using postoperative computed tomography (CT). All the screws were safely implanted, as confirmed using intraoperative fluoroscopy. Postoperative CT confirmed that all the screws were in the cancellous bone. This system combines the doctor's initiative with the Robot's stability. The remote control of this procedure is possible. Robot-assisted surgery has a higher position-retention capacity compared with conventional methods. In contrast to active robotic systems, surgeons have full control over the operation. The robot system is fully compatible with operating room systems and does not require additional equipment.

A senior orthopedic surgeon completed the surgery using the procedure described. All the screws (three in S1 and two in S2) were secured. The time taken (from the first X-ray fluoroscopy to the insertion of the screw) for inserting each of the five screws was 32 min, 28 min, 26 min, 20 min, and 23 min, respectively. The fluoroscopy time for each screw was approximately 5 min. Although all the screws were in the correct place on the intraoperative fluoroscopic images, several articles have highlighted the need for postope...

Watch this Scientific Journal Video about A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique at JoVE.com

A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique

Teleoperated robotic system-assisted percutaneous transiliac-transsacral screw fixation is a feasible technique. Screw channels can be implemented with high accuracy owing to the excellent freedom of movement and stability of the robotic arms.

Transiliac-transsacral screw fixation is challenging in clinical practice as the screws need to break through six layers of cortical bone. ...

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2.2K Views.  Huazhong University of Science and Technology. Transiliac-transsacrale schroeffixatie is een uitdagende taak in de klinische praktijk. De teleoperatieve robotsysteem-geassisteerde chirurgie biedt een oplossing voor de moeilijkheid van transiliac-transsacrale schroefplaatsing. Met behulp van deze techniek kunnen chirurgen procedures buiten de operatiekamer uitvoeren, waardoor het gevaar van blootstelling aan straling wordt vermeden.Bovendien heeft robot-geassisteerde chirurgie een hogere positieretentiecapaciteit in vergelijking met...

Video: A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique

Time Multiplexing Super Resolving Technique for Imaging from a Moving Platform

We propose a method for increasing the resolution of an object and overcoming the diffraction limit of an optical system installed on top of a moving imaging system, such as an airborne platform or satellite. The resolution improvement is obtained in a two-step process. First, three low resolution differently defocused images are being captured and the optical phase is retrieved using an improved iterative Gerchberg-Saxton based algorithm. The phase retrieval allows to numerically back propagate the field to the aperture plane. Second, the imaging system is shifted and the first step is repeated. The obtained optical fields at the aperture plane are combined and a synthetically increased lens aperture is generated along the direction of movement, yielding higher imaging resolution. The method resembles a well-known approach from the microwave regime called the Synthetic Aperture Radar (SAR) in which the antenna size is synthetically increased along the platform propagation direction. The proposed method is demonstrated through laboratory experiment.

A method for overcoming the optical diffraction limit is presented. The method includes a two-step process: optical phase retrieval using iterative Gerchberg-Saxton algorithm, and imaging system shifting followed by repetition of the first step. A synthetically increased lens aperture is generated along the direction of movement, yielding higher imaging resolution.

We propose a method for increasing the resolution of an object and overcoming the diffraction limit of an optical system installed on top of a moving ...

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for detailed observation, scenarios that make it challenging to observe with conventional imaging systems. One of these is the drop impact of liquids, which usually happens within one tenth of millisecond. To tackle this challenge, a fast imaging technique is introduced that combines a high-speed camera (capable of up to one million frames per second) with a macro lens with long working distance to bring the spatial resolution of the image down to 10 &#181;m/pixel. The imaging technique enables precise measurement of relevant fluid dynamic quantities, such as the flow field, the spreading distance and the splashing speed, from analysis of the recorded video. To demonstrate the capabilities of this visualization system, the impact dynamics when droplets of non-Newtonian fluids impinge on a flat hard surface are characterized. Two situations are considered: for oxidized liquid metal droplets we focus on the spreading behavior, and for densely packed suspensions we determine the onset of splashing. More generally, the combination of high temporal and spatial imaging resolution introduced here offers advantages for studying fast dynamics across a wide range of microscale phenomena.

Drop impact of non-Newtonian fluids is a complex process since different physical parameters influence the dynamics over a very short time (less than one tenth of a millisecond). A fast imaging technique is introduced in order to characterize the impact behaviors of different non-Newtonian fluids.

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for ...

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

Prescribed 3-D Direct Writing of Suspended Micron/Sub-micron Scale Fiber Structures via a Robotic Dispensing System

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer fiber length and orientation is defined by the spatial positioning of the dispensing system 3-axis stages. The fiber diameter is defined by the prescribed dispense time of the dispensing system valve, the feed rate (the speed at which the stage traverses from an initiating to a terminating position), the gauge diameter of the dispensing tip, the viscosity and surface tension of the polymer solution, and the programmed drawing length. The stage feed rate affects the polymer solution&#8217;s evaporation rate and capillary breakup of the filaments. The dispensing system consists of a pneumatic valve controller, a droplet-dispensing valve and a dispensing tip. Characterization of the direct write process to determine the optimum combination of factors leads to repeatedly acquiring the desired range of fiber diameters. The advantage of this robotic dispensing system is the ease of obtaining a precise range of micron/sub-micron fibers onto a desired, programmed location via automated process control. Here, the discussed self-assembled micron/sub-micron scale 3D structures have been employed to fabricate suspended structures to create micron/sub-micron fluidic devices and bioengineered scaffolds.

Here, we present a protocol to fabricate freely-suspended, micron/sub-micron scale polymer fibers and &#8220;web-like&#8221; structures generated via automated direct writing procedure by means of a 3-axis dispensing system.

A 3-axis dispensing system is utilized to control the initiating and terminating fiber positions and trajectory via the dispensing software. The polymer ...

A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement

Pedicle screw implantation has excellent treatment effects and is often used by surgeons in spinal fusion surgery. However, due to the complexity of human body anatomy, this surgical procedure is difficult and challenging, especially in minimally invasive surgery or patients with congenital anomalies and kyphoscoliosis deformity. In addition to the abovementioned factors, the surgical experience and technique of the surgeon also affect the recovery rates and complications of the patients after the surgical operation. Therefore, accurately performing pedicle screw implantation has is a constant topic of common concern for surgeons and patients. In recent years, with the technological development, robot-assisted navigation systems have gradually become adopted. These robot-assisted navigation systems provide surgeons with complete preoperative planning before surgery. The system provides 3D reconstructed images of each vertebra, allowing surgeons to understand the patient&#39;s physiological characteristics more quickly. It also provides 2D images of sagittal, coronal, axial and oblique planes so that surgeons can accurately perform pedicle screw placement plan.
Previous studies have demonstrated the effectiveness of robot-assisted navigation systems for pedicle screw implantation procedures, including accuracy and safety assessments. This step-by-step protocol aims to outline a standardized surgical technique note for robotic-assisted pedicle screw placement.

This article presents a standardized surgical technique for robotic-assisted pedicle screw placement by using robotic-assisted navigational systems. We present a step-by-step protocol and describe the workflow and precautions of this procedure.

Pedicle screw implantation has excellent treatment effects and is often used by surgeons in spinal fusion surgery. However, due to the complexity of human ...

Bioengineering

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle screws after spinal surgery, which is a serious concern. To address this problem, diverse types of pedicle screws have been examined to identify those with good fixation strength and osseointegration in spine bone. The porcine spine is a good alternative for the human spine in the evaluation of pedicle screws due to the anatomical size, mechanical characteristics, and cost. Although several studies have reported that pedicle screws are efficient in the porcine model, no study has described detailed protocols for the evaluation of a pedicle screw using the porcine model. Here, we describe a detailed method for evaluating transpedicular screws using an in vivo porcine lumbar spine model. The technical details for anesthesia, spine surgery, and harvest provided here will facilitate with the evaluation of the transpedicular screw fixation model.

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Here, we introduce a method to evaluate transpedicular screws by using an in vivo porcine lumbar spine model.

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle ...

Medicine

Cone Beam Intraoperative Computed Tomography-based Image Guidance for Minimally Invasive Transforaminal Interbody Fusion

Transforaminal lumbar interbody fusion (TLIF) is commonly used for the treatment of spinal stenosis, degenerative disc disease, and spondylolisthesis. Minimally invasive surgery (MIS) approaches have been applied to this technique with an associated decrease in estimated blood loss (EBL), length of hospital stay, and infection rates, while preserving outcomes with traditional open surgery. Previous MIS TLIF techniques involve significant fluoroscopy that subjects the patient, surgeon, and operating room staff to non-trivial levels of radiation exposure, particularly for complex multi-level procedures. We present a technique that utilizes an intraoperative computed tomography (CT) scan to aid in placement of pedicle screws, followed by traditional fluoroscopy for confirmation of cage placement. Patients are positioned in the standard fashion and a reference arc is placed in the posterior superior iliac spine (PSIS) followed by intraoperative CT scan. This allows for image-guidance-based placement of pedicle screws through a one-inch skin incision on each side. Unlike traditional MIS-TLIF that requires significant fluoroscopic imaging during this stage, the operation can now be performed without any additional radiation exposure to the patient or operating room staff. After completion of the facetectomy and discectomy, final TLIF cage placement is confirmed with fluoroscopy. This technique has the potential to decrease operative time and minimize total radiation exposure.

The purpose of this article is to provide image-guidance for minimally invasive transforaminal interbody fusion.

Transforaminal lumbar interbody fusion (TLIF) is commonly used for the treatment of spinal stenosis, degenerative disc disease, and spondylolisthesis. ...

C-arm-Free Simultaneous OLIF51 and Percutaneous Pedicle Screw Fixation in a Single Lateral Position

Oblique lumbar interbody fusion (OLIF) is an established technique for the indirect decompression of lumbar canal stenosis. However, OLIF at the L5-S1 level (OLIF51) is technically difficult because of the anatomical structures. We present a novel simultaneous technique of OLIF51 with percutaneous pedicle screw fixation without fluoroscopy. The patient is placed in a right lateral decubitus position. A percutaneous reference pin is inserted into the right sacroiliac joint. An O-arm scan is performed, and 3D reconstructed images are transmitted to the spinal navigation system. A 4 cm oblique skin incision is made under navigation guidance along the pelvis. The internal/external and transverse abdominal muscles are divided along the muscle fibers, protecting the iliohypogastric and ilioinguinal nerves. Using a retroperitoneal approach, the left common iliac vessels are identified. Special muscle retractors with illumination are used to expose the L5-S1 intervertebral disc. After disc preparation with navigated instruments, the disc space is distracted with navigated trials. Autogenous bone and demineralized bone material are then inserted into the cage hole. The OLIF51 cage is inserted into the disc space with the help of a mallet. Simultaneously, percutaneous pedicle screws are inserted by another surgeon without changing the lateral decubitus position of the patient.
In conclusion, C-arm-free OLIF51 and simultaneous percutaneous pedicle screw fixation are performed in a lateral position under navigation guidance. This novel technique reduces surgical time and radiation hazards.

C-arm-free oblique lumbar interbody fusion at the L5-S1 level (OLIF51) and simultaneous pedicle screw fixation are performed in a lateral position under navigation guidance. This technique does not expose the surgeon or operating staff to radiation hazards.

Oblique lumbar interbody fusion (OLIF) is an established technique for the indirect decompression of lumbar canal stenosis. However, OLIF at the L5-S1 ...

Orthopedic Robot-Assisted Femoral Neck System in the Treatment of Femoral Neck Fracture

Cannulated screw fixation is the main therapy for femoral neck fractures, especially in young patients. The traditional surgical procedure uses C-arm fluoroscopy to place the screw freehand and requires several guide wire adjustments, which increases the operation time and radiation exposure. Repeated drilling can also cause damage to the blood supply and bone quality of the femoral neck, which can be followed by complications such as screw loosening, nonunion, and femoral head necrosis. In order to make fixation more precise and reduce the incidence of complications, our team applied robot-assisted orthopedic surgery for screw placement using the femoral neck system to modify the traditional procedure. This protocol introduces how to import a patient's X-ray information into the system, how to perform screw path planning in software, and how the robotic arm assists in screw placement. Using this method, the surgeons can place the screw successfully the first time, improve the accuracy of the procedure, and avoid radiation exposure. The whole protocol includes the diagnosis of femoral neck fracture; the collection of intraoperative X-ray images; screw path planning in the software; precise placement of the screw under the assistance of the robotic arm by the surgeon; and verification of the implant placement.

This article introduces a method of robot-assisted orthopedic surgery for screw placement during the treatment of femoral neck fracture using the femoral neck system, which allows for more accurate screw placement, improved surgical efficiency, and fewer complications.

Cannulated screw fixation is the main therapy for femoral neck fractures, especially in young patients. The traditional surgical procedure uses C-arm ...

Technique of Sagittal Adjusting Screw System for Thoracolumbar Burst Fractures

Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device

Thoracolumbar (TL) burst fracture is one of the most common indications for minimally invasive percutaneous pedicle screw fixation. Although the indication for surgical treatment of neurologically intact TL fractures remains under debate, studies have demonstrated that posttraumatic malalignment may lead to a deterioration in the patient&#39;s quality of life. For burst fractures with malalignment or fragments in the spinal canal, a reduction technique using ligamentotaxis is commonly used to improve long-term outcomes.
The sagittal adjusting screw (SAS) system is a monoaxial screw system with a fixed head and concave sliding saddle that allows lordotic sliding of the rod in the sagittal plane after screw insertion. SAS also has a percutaneous option and has been used for TL spine fractures. Notably, the SAS only allows motion on the sagittal plane, allowing both secure fixation and angular reduction. The SAS has certain advantages over the conventional Schanz screw system or normal mono-/multiaxial pedicle screws for TL spine fracture treatment. In addition, specialized trauma reduction devices are available for the SAS system. In this video protocol, we discuss the indication for the SAS system in TL burst fracture and describe a technique of TL burst fracture reduction and fixation using the SAS system. Additionally, we describe our recent case series with radiological evaluation, including regional kyphotic angle and percent loss of anterior vertebral body height, to evaluate the newly introduced trauma reduction device.

The sagittal adjusting screw (SAS) system has been widely used for thoracolumbar (TL) spinal trauma. Percutaneous options and specialized trauma reduction devices are also available for the SAS system. We describe a technique for reducing TL burst fractures using an SAS system and a newly introduced trauma reduction device.

A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique

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