Simulated Puncture Research Articles

Modeling, Analysis and Evaluation of a Novel Compact 6-DoF 3-RRRS Needle Biopsy Robot

Robot-assisted surgical systems have been widely applied for minimally invasive needle biopsies thanks to their excellent accuracy and superior stability compared to manual surgical operations, which lead to possible fatigue and misoperation due to long procedures. Current needle biopsy robots are normally customed designed for specific application scenarios, and only position-level kinematics are derived, preventing advanced speed control or singularity analysis. As a step forward, this paper aims to design a universal needle biopsy robot platform which features 6 DoF 3-RRRS (Revolute–Revolute–Revolute–Spherical) parallel structure. The analytical solutions to its nonlinear kinematic problems, including forward kinematics, inverse kinematics, and differential kinematics are derived, allowing fast and accurate feedback control calculations. A multibody simulation platform and a first-generation prototype are established next to provide comprehensive verifications for the derived robotic model. Finally, simulated puncture experiments are carried out to illustrate the effectiveness of the proposed method.

A novel simple laser guidance puncture system for intracerebral hematoma

ObjectiveAccurate localization and real-time guidance technologies for cerebral hematomas are essential for minimally invasive procedures, including minimally invasive hematoma puncture and drainage, as well as neuroendoscopic-assisted hematoma removal. This study aims to evaluate the precision and safety of a self-developed laser-guided device in localizing and guiding hematoma punctures in minimally invasive surgery for intracerebral hemorrhage (ICH). MethodsWe present the components of the device and its operational procedures. Subsequently, surgeons with different titles conduct hematoma puncture experiments using the device on skull models, comparing it to freehand puncture methods and recording the offset distance from the puncture needle tip to the hematoma center. Additionally, we report the application of this device in 10 patients with ICH, assessing its accuracy and safety in comparison with a neuro-navigation system. ResultsIn simulated puncture experiments, the accuracy of the laser-guided group surpasses that of the freehand puncture group, with a significant statistical difference observed between the two groups (P < 0.05). In the laser-guided group, there is no statistically significant difference in puncture accuracy among the surgeons (P > 0.05). In clinical experiments, no relevant surgical complications were observed. The offset distance for the laser-guided group was 0.61 ± 0.18 cm, while the neuro-navigation group was 0.48 ± 0.13 cm. There was no statistically significant difference between the two groups in terms of offset distance (P > 0.05). However, there was a significant difference in surgical duration (P < 0.05), with the former being 35.0 ± 10.5 minutes and the latter being 63.8 ± 10.5 minutes. ConclusionThe current study describes satisfactory results from both simulated experiments and clinical applications, achieved through the use of a novel laser-guided hematoma puncture device. Furthermore, owing to its portability, affordability, and simplicity, it holds significant importance in advancing surgical interventions for ICH, especially in underdeveloped regions.

6DOF pose estimation of a 3D rigid object based on edge-enhanced point pair features

The point pair feature (PPF) is widely used for 6D pose estimation. In this paper, we propose an efficient 6D pose estimation method based on the PPF framework. We introduce a well-targeted down-sampling strategy that focuses on edge areas for efficient feature extraction for complex geometry. A pose hypothesis validation approach is proposed to resolve ambiguity due to symmetry by calculating the edge matching degree. We perform evaluations on two challenging datasets and one real-world collected dataset, demonstrating the superiority of our method for pose estimation for geometrically complex, occluded, symmetrical objects. We further validate our method by applying it to simulated punctures.

An MRI study of lateral vascular safety zones in oblique lumbar interbody fusion surgery

To study the anatomical characteristics of blood vessels in the lateral segment of the vertebral body through the surgical approach of oblique lumbar interbody fusion (OLIF) using MRI imaging, and evaluate its potential vascular safety zone. The lumbar MRI data of 107 patients with low back and leg pain who met the selection criteria between October 2019 and November 2022 were retrospectively analyzed. The vascular emanation angles, vascular travel angles, and the length of vessels in the lateral segments of the left vertebral body of L 1-L 5, as well as the distance between the segmental vessels in different Moro junctions of the vertebral body and their distances from the edges of the vertebrae in the same sequence (bottom marked as I, top as S) were measured. The gap between the large abdominal vessels and the lateral vessels of the vertebral body was set as the lateral vascular safe zones of the lumbar spine, and the extent of the safe zones (namely the area between the vessels) was measured. The anterior 1/3 of the lumbar intervertebral disc was taken as the simulated puncture center, and the area with a diameter of 22 mm around it as the simulated channel area. The proportion of vessels in the channel was further counted. In addition, the proportions of segmental vessels at L 5 without a clear travel and with an emanation angel less than 90° were calculated. Except for the differences in the vascular emanation angles between L 4 and L 5, the vascular travel angles between L 1, L 2 and L 4, L 5, and the length of vessels in the lateral segments of the vertebral body among L 1-L 4 were not significant ( P>0.05), the differences in the vascular emanation angles, vascular travel angles, and the length of vessels between the rest segments were all significant ( P<0.05). There was no significant difference in the distance between vessels of L 1, L 2 and L 2, L 3 at Moro Ⅰ-Ⅳ junctions ( P>0.05), in L 3, L 4 and L 4, L 5 at Ⅱ and Ⅲ junction ( P>0.05). There was no significant difference in the vascular distance of L 2, L 3 between Ⅱ, Ⅲ junction and Ⅲ, Ⅳ junction, and the vascular distance of L 3, L 4 between Ⅰ, Ⅱ junction and Ⅲ, Ⅳ junction ( P>0.05). The vascular distance of the other adjacent vertebral bodies was significant different between different Moro junctions ( P<0.05). Except that there was no significant difference in the distance between L 2I and L 3S at Ⅰ, Ⅱ junction, L 3I and L 4S at Ⅱ, Ⅲ junction, and L 2I and L 3S at Ⅲ, Ⅳ junction ( P>0.05), there was significant difference of the vascular distance between the bottom of one segment and the top of the next in the other segments ( P<0.05). Comparison between junctions: Except for the L 3S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ junction, and L 5S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ and Ⅲ, Ⅳ junctions had no significant difference ( P>0.05), there were significant differences in the distance between the other segmental vessels and the vertebral edge of the same sequence in different Moro junctions ( P<0.05). The overall proportion of vessels in the simulated channels was 40.19% (43/107), and the proportion of vessels in L 1 (41.12%, 44/107) and L 5 (18.69%, 20/107) was higher than that in the other segments. The proportion of vessels in the channel of Moro zone Ⅰ (46.73%, 50/107) and zone Ⅱ (32.71%, 35/107) was higher than that in the zone Ⅲ, while no segmental vessels in L 1 and L 2 were found in the channel of zone Ⅲ ( χ 2=74.950, P<0.001). Moreover, 26.17% (28/107) of the segmental vessels of lateral L 5 showed no movement, and 27.10% (29/107) vascular emanation angles of lateral L 5 were less than 90°. L 1 and L 5 segmental vessels are most likely to be injured in Moro zones Ⅰ and Ⅱ, and the placement of OLIF channels in L 4, 5 at Ⅲ, Ⅳ junction should be avoided. It is usually safe to place fixation pins at the vertebral body edge on the cephalic side of the intervertebral space, but it is safer to place them on the caudal side in L 1, 2 (Ⅰ, Ⅱ junction), L 3, 4 (Ⅲ, Ⅳ junction), and L 4, 5 (Ⅱ, Ⅲ, Ⅳ junctions).

Application of image overlapping in percutaneous nephrolithotomy.

To investigate the application of ultrasound and CT image overlap in percutaneous nephrolithotomy (PCNL). A total of 140 patients with complicated kidney stones requiring PCNL were prospectively enrolled, from January 2020 to December 2022. These patients were randomly divided into 2 groups, with 70 patients each in the research group and the control group. All participants underwent dual-source, non-contrast CT scan of both kidneys and pelvis before surgery. Preoperative three-dimensional CT reconstruction and simulated puncture were performed in patients from the research group. The best puncture path was determined through ultrasound and CT image overlap. Puncture guided by regular CT and ultrasound was conducted in patients from the control group. Differences in the surgical outcomes between the two groups were compared. Compared to the control group, the research group had higher stone clearance rate in stage I PCNL, success rate of one-time puncture, less percutaneous channels, less reduction of hemoglobin and shorter procedure time. Complications in stage I PCNL were comparable in the two groups, and there was no significant change in the final stone clearance rates between the two groups. An optimal puncture channel can be chosen using ultrasound and CT image overlap. PCNL can be achieved with precise puncturing, thus achieving coincidence between imaging and anatomy and reducing the amount of blood loss during stage I of PCNL. It also shortens the procedure time and improves stone clearance rate of PCNL.

The foramen ovale: a keyhole to the brain? Computer simulations of percutaneous FO punctures

BackgroundThe percutaneous cannulation of the foramen ovale (FO) is implemented in treating trigeminal neuralgia, diagnosing temporal lobe epilepsy and biopsy petroclival lesions. This study dealt with the question whether it is possible to reach intracerebral structures with a puncture beyond the Gasserian Ganglion (GG) without bone destruction or perforating vascularity.MethodsWe considered the FO a natural keyhole and performed computer-simulated punctures through the right and left FO to eight intracerebral structures. Therefore, we took the Hartel and Submandibular (SM) approach as a starting point and planned trajectories with stereotactic planning software by using brain scans of ten patients.ResultsThe simulated punctures with the Hartel approach directly reached the hippocampus (20 out of 20 trajectories), the lateral ventricle (15/20) and the amygdala (2/20). The pons was reached (20/20); however, the pontine vascularity was within the course. The trajectories to the thalamus (13/20) ran through the hippocampus or the mesencephalon. The simulated punctures with the SM approach directly reached the amygdala (18/20), the lateral ventricle (5/20) and the putamen (20/20). The trajectories to the nucleus caudatus (20/20) pierced the hippocampus, the putamen or the maxillary artery. The courses to the thalamus (7/20) ran through the hippocampus or the mesencephalon. The sinus cavernosus could not be reached with the Hartel or SM approach.ConclusionsThis study indicates that a percutaneous approach to the hippocampus, the lateral ventricle, the amygdala and the putamen is possible without harming major vessels or bone destruction. For a possible implementation of these trajectories in a clinical setting, it is necessary to prove these simulated punctures in cadaveric studies.

A A Novel Computed Tomography-Ultrasound Image Fusion Technique for Guiding the Percutaneous Kidney Access.

To describe the feasibility of computed tomography (CT)-ultrasound image fusion technique on guiding percutaneous kidney access in vitro and vivo. we compare CT-ultrasound image fusion technique and ultrasound for percutaneous kidney puncture guidance by using an in vitro pig kidney model. The fusion method, fusion time, ultrasound screening time, and success rate of puncture were compared between the groups. Next, patients with kidney stones in our hospital were randomized in the study of simulated puncture guidance. The general condition of patients, fusion method, fusion time, and ultrasound screening time were compared between the groups. A total of 45 pig models were established, including 23 in CT-ultrasound group and 22 in ultrasound group. The ultrasound screening time in CT-ultrasound group was significantly shorter than that in ultrasound group (P < .001). In addition, the success rate of puncture in CT-ultrasound group was significantly higher than that in ultrasound group (P =.015). Furthermore, in simulated PCNL puncture study, baseline data including age, BMI, and S.T.O.N.E score between the two groups showed no statistical difference. The ultrasound screening time of the two groups was (2.60 ± 0.33) min and (3.37 ± 0.51) min respectively, and the difference was statistically significant (P < .001). Our research revealed that CT-ultrasound image fusion technique was a feasible and safe method to guide PCNL puncture. Compared with traditional ultrasound guidance, CT-ultrasound image fusion technique can shorten the learning curve of PCNL puncture, improve the success rate of puncture, and shorten the ultrasound screening time.

Laser Navigation Combined With XperCT Technology Assisted Puncture of Brainstem Hemorrhage.

BackgroundBrainstem hemorrhage has a rapid onset with high mortality and disability rates. In recent years, an increasing number of studies have reported on the surgical treatment of brainstem hemorrhage. The introduction of stereotaxic instruments and navigation systems has improved the accuracy of surgical treatment; however, the popularity of these devices in the primary hospitals is not high. In this study, we introduce laser navigation combined with the XperCT technology to assist in the puncture and drainage of brainstem hemorrhage, aiming to improve surgical accuracy and facilitate the drainage of brainstem hemorrhage in primary hospitals.Material and MethodsA total of five patients (four men and one woman), aged 34–70 years, who underwent hematoma puncture drainage with the assistance of laser navigation combined with XperCT technology at the Binzhou Medical University Hospital, China, between June 2020 and Aug 2021 were included in the study. The brainstem hemorrhages had volumes of 7–18 ml. Statistical analyses of the postoperative puncture deviation distance (distance between the actual puncture end and simulated puncture end) and postoperative improvement were also performed.ResultsThe operations were successfully completed in all five patients. The puncture deviation distance was <6 mm in all five patients and <2 mm in two patients. The postoperative hematoma clearance rate was about 70%−90%. Among four patients with respiratory failure, three had improved breathing and resumed spontaneous breathing. Out of three patients with high fever, one showed a substantial decrease in body temperature. There were no cases of postoperative infection. Of the five patients, two recovered consciousness, one died, and two voluntarily gave up further treatment and were discharged.ConclusionsLaser navigation combined with the XperCT technology could improve the accuracy of surgical puncture. The technique might be convenient for widespread clinical application because of its low trauma, high precision, short operation time, and low operation cost.

Consideration of Yarn Anisotropy in the Investigation of the Puncture Resistance of Fibrous Materials.

High-performance yarns are widely used to produce protective fabrics, including stab-resistant materials. The most common approach to studying the mechanism of puncture prevention is to use simulation to assist analysis. However, the anisotropy of the yarn is often overlooked during simulation owing to various factors. In fact, there is a marked difference between the axial and radial properties of a yarn. This may lead to large errors in research. In the present study, a composite material with a grid structure for puncture analysis was designed to investigate the influence of yarn anisotropy on the accuracy of simulation results. The present study combined an actual experiment with a simulation. In the actual experiment, Kevlar yarn/epoxy resin was used to prepare a mesh composite with a spacing of 1 mm. In the simulation, a 1:1 simulation model of composite material was established using finite element software. A simulated puncture experiment was conducted based on the actual experimental conditions and material parameters. After considering yarn anisotropy, the simulation results were closer to the actual experimental results. The simulation revealed that the main failure modes of the mesh material were the fracture of the resin and the bending deformation of the yarns at the junctions, while the surrounding areas were almost unaffected.

Bite force estimates in juvenile Tyrannosaurus rex based on simulated puncture marks.

BackgroundBite marks attributed to adult Tyrannosaurus rex have been subject to numerous studies. However, few bite marks attributed to T. rex have been traced to juveniles, leaving considerable gaps in understanding ontogenetic changes in bite mechanics and force, and the paleoecological role of juvenile tyrannosaurs in the late Cretaceous.MethodsHere we present bite force estimates for a juvenile Tyrannosaurus rex based on mechanical tests designed to replicate bite marks previously attributed to a T. rex of approximately 13 years old. A maxillary tooth of the juvenile Tyrannosaurus specimen BMR P2002.4.1 was digitized, replicated in dental grade cobalt chromium alloy, and mounted to an electromechanical testing system. The tooth was then pressed into bovine long bones in various locations with differing cortical bone thicknesses at varying speeds for a total of 17 trials. Forces required to replicate punctures were recorded and puncture dimensions were measured.ResultsOur experimentally derived linear models suggest bite forces up to 5,641.19 N from cortical bone thickness estimated from puncture marks on an Edmontosaurus and a juvenile Tyrannosaurus. These findings are slightly higher than previously estimated bite forces for a juvenile Tyrannosaurus rex of approximately the same size as BMR P2002.4.1 but fall within the expected range when compared to estimates of adult T. rex.DiscussionThe results of this study offer further insight into the role of juvenile tyrannosaurs in late Cretaceous ecosystems. Furthermore, we discuss the implications for feeding mechanisms, feeding behaviors, and ontogenetic niche partitioning.

Application of simulated puncture in percutaneous nephrolithotomy.

This study aimed to explore the clinical value of simulated puncture in percutaneous nephrolithotomy in the treatment of complex kidney stones. A total of 120 patients with complex kidney stones who were treated with percutaneous nephrolithotomy in our hospital between March 2017 and March 2020 were enrolled in this study and randomly divided into two groups: the research group and the control group (n = 60 in each). Each subject underwent a dual-source computed tomography (CT) scan of the pelvis and both kidneys before the operation. The research team imported the CT data into Mimics19 software to create a three-dimensional (3D) reconstruction of the skin, bones, kidneys, collecting system, and stones. Based on the 3D reconstruction model, the target renal calyx to be punctured was determined, the best puncture channel was designed, and puncture was simulated. Data regarding the simulated puncture were imported into 3-Matics11 software; the angle and depth of the puncture were measured, and then these data were used to guide percutaneous nephrolithotomy. 3D reconstruction and simulated puncture were not undertaken for the patients in the control group before the operation. The effects of treatment in the two groups were compared. First-stage percutaneous nephrolithotomy was successfully completed in both groups of patients. The outcome was better in the research group than in the control group in terms of operation time, number of punctures required for successful establishment of a percutaneous renal channel, number of percutaneous kidney puncture channels, and intraoperative blood loss, and the differences were statistically significant (p < 0.05 for all). The stone clearance rate was higher in the research group than in the control group, but the difference was not statistically significant (p = 0.471). The incidence of penetrating kidney injury was lower in the research group than in the control group, but the difference was not statistically significant (p = 0.154). For patients due to undergo percutaneous nephrolithotomy for the treatment of complex kidney stones, preoperative simulated puncture helps to improve the puncture accuracy and to reduce the number of punctures required for successful establishment of a percutaneous renal channel, the number of puncture channels, the operation time, and the blood loss, and therefore it is worth promoting.

Computer Three-Dimensional Reconstruction and Pain Management for Lumbar Disc Herniation Treated by Intervertebral Foramen Endoscopy

Objective: Lumbar disc herniation leads the numbness and pain in the waist and lower limbs. Intervertebral foramen endoscopy is a minimally invasive procedure for the treatment of disc herniation. Adequate preoperative evaluation is conducive to this percutaneous skin surgery. The purpose of this study is to improve the efficacy of intervertebral foramen endoscopy in the treatment of lumbar disc herniation by preoperative computer three-dimensional reconstruction combined with pain management. Method: Fifty patients with lumbar disc herniation who met the indications of intervertebral foramen endoscopy were randomly divided into experimental group and control group. The control group was operated according to experience based on the common axial image. The experimental group was punctured according for three-dimensional visualization model of lumbar spine. Preoperative simulated puncture catheterization and perioperative pain management was applied. The catheterization time, operation time under endoscopy, fluoroscopy times during operation, the Visual Analogue Scale (VAS) and Japanese Orthopaedic Association (JOA) scores before and 1 d, 1 m and 3 m after operation were compared between two groups. Result: The three-dimensional visualization model of lumbar spine was reconstructed based on thin-layer data. According to the results of software measurement, the skin puncture point was located and the puncture angle was obtained. Compared with the control group, the catheterization time, operation time under endoscopy, fluoroscopy times during operation in experimental group were significantly reduced. There was no statistical difference in VAS and JOA scores between two groups before operation. Compared with control group, the VAS scores in experimental group at 1 d, and 1 m after operation were decreased statistically, while the JOA scores were increased statistically. Conclusion: Three-dimensional visualization model of lumbar spine and virtual operation planning can directly judge the feasibility of intervertebral foramen endoscopy in the treatment of lumbar disc herniation, improve the efficiency of operation, and further improve postoperative efficacy with pain management.

Digital modeling and analysis of the applicability of backward rotation method in lumbar kyphoplasty with unilateral puncture

The 3D model of lumbar spine was established by using Mimics software. To observe the applicability and needling parameters of lumbar vertebral kyphoplasty with unilateral puncture by backward rotation method using simulated puncture. Twenty-four patients (12 males and 12 females) with osteoporotic thoracic fracture in the first time and no signs of lumbar misalignment and bone destruction were scanned by spiral CT on the lumbar spine. The original DICOM file was modeled in 3D with Mimics software, and the vertebral bodies were separated. After being imported into 3-matic software, the posterior wall of the vertebral body was restrained for standardized measurement. A sketch perpendicular to the mid-section of the pedicle and the posterior wall of the vertebral body was drawn. The simulated puncture was performed on the sketch. The angle and distance parameters of the range of motion of the puncture needle were recorded, and the puncture needle was recorded at the top. The crossing points of the anterior, middle and posterior zones of the tangential line of the vertebral body were located at the high extraversion angle, and the results were compared and analyzed. All the data in the left and right sides had no significantly differences(P>0.05). Data of different segments in different gender were significantly differences(P<0.05). The maximal extraversion angle in lumbar spine increased gradually from (33.41±1.31) degree to (56.53±4.71) degree in males, as same as in females from(28.58±2.55) to (53.86±2.68) degree. There was no crossing point in area A, 3.3% of males and 26.67% of females in area B, rest in area C. The distribution areas on gender showed statistically significance (P<0.05). Backward rotation method can theoretically meet the requirements of puncture point for vertebral compression fracture, especially for males and lower lumbar spine. The determination of the maximum inclination angle is of guiding significance to the backward rotation method.

The effect of calculus model made by preoperative 3D printing technique on the puncture accuracy and postoperative complications of percutaneous nephrolithotomy

Objective To investigate the effect of calculus model made by preoperative 3D printing technique on the puncture accuracy and postoperative complications of percutaneous nephrolithotomy (PCNL). Methods Thirteen patients with kidney calculi who underwent PCNL in our hospital between June 2014 and August 2016 were selected as study subjects, and all patients underwent ultrasound and 64 slice spiral CT examination before operation. The DICOM formatted files of CT were processed by the 3D medical image data processing platform. The thermoplastic plastics were used for 3D print, and the 3D kidney calculus models were obtained. 3D stone kidney model was obtained and simulated puncture in vitro. Analysis the function of 3D model of PCNL instructed to establish percutaneous renal access.The operation time, intraoperative blood loss, stone clearance rate, postoperative hospital stay and postoperative complications were observed. Results The 3D calculus models of 13 patients were successfully printed, There were no significant differences in the renal length, transverse diameterand the longest diameter [(11.89±0.46) cm, (6.87±0.25) cm, (4.10±0.27) cm] under 3D models and the the actual values (P>0.05). The accuracy of 3D model guided PCNL was 100%, and there was no significant differences between the estimated puncture depth [(5.76±0.65) cm] and the actual puncture depth [(6.14±0.34) cm, P>0.05]. The total score of the 3D model was (30.13±1.55), and the scores of patients and their family members on the 3D models was (31.45±0.99). Operation time(55±24) min, and intraoperative blood loss was(62.2±12.7)mL, postoperative hospitalization was(5.5±1.2)d. There were no complications such as peripheral organ injury, bleeding and infection in 13 patients. Conclusions The 3D printing models can better reflect the relationship between the stones and the surrounding tissues, guide the accurate puncture of PCNL and communication between doctors and patients, and reduce postoperative complications, which is worthy of clinical application. Key words: Kidney Calculi; Nephrostomy, Percutaneous; Postoperative Complications

Oblique puncture approach via anterolateral to C2: a study of imaging anatomy on corpses

Objective: To determine the anatomical relation between the carotid artery or laryngopharynx and the needle path via anterolateral oblique approach to C2 vertebral body, and whether the simulated path can direct the actual procedure. Methods: Contrast agent was injected into bilateral carotid arteries of 10 fresh cadavers (20 sides), and then CT scans were performed on each subject. Bilateral simulated puncture paths were simulated on the image of two-dimensional reconstruction CT. The distance between the puncture site and middle line(AC), the angle between the simulated puncture paths and the median sagittal plane (AOB), the distance between the simulated puncture paths and the side wall of hypopharynx, or the carotid artery was measured respectively. Under the guidance of fluoroscopy, oblique puncture via anterolateral to C2 was performed according to the simulated parameters, and then CT was done. The actual needle path was measured on the image of two-dimensional reconstruction CT. The outcomes were compared by using paired t test between groups. Results: Bilateral simulated puncture paths in all 10 cadavers were achieved on the image of CT. The bilateral punctures via anterolateral to C2 were successfully performed under fluoroscopic guidance in 10 cadavers, and the actual needle path could be showed on the image of two-dimensional reconstruction CT. The AC, angle AOB, the distance to carotid artery and side wall of laryngopharyngeal of the left simulated path was(4.7±1.0)cm, (33±8)°, (6.7±2.6)mm, (6.6±2.8)mm, respectively; and those in the right side was(5.2±1.3) cm, (36±8)°, (7.5±2.2) mm, (7.2±2.5) mm, respectively.The AC, angle AOB, the distance to carotid artery and side wall of laryngopharyngeal of the left actual needle was(4.5±1.1) cm, (33±9) °, (6.7±3.0) mm, (7.1±3.9) mm, respectively; and those in the right side was(5.1±1.5) cm, (35±10) °, (7.4±2.1) mm, (7.2±2.6) mm, respectively.And the actual and simulation data of both sides were compared and no significant differences was found by t test (t=0.104-1.882, all P>0.05). Conclusion: The simulated approach via anterolateral to C2 can be achieved on the image of two-dimensional reconstruction CT, it is consistent with the real needle path and can be used to direct the actual practice to improve the accuracy and safety.

Validation of the imperial college surgical assessment device for spinal anesthesia

BackgroundTraditionally, technical proficiency for spinal anesthesia has been assessed using observational scales such as global rating scales or task specific checklists. However more objective metrics are required in order to improve novice’s training programs. The aim of this study is to validate the hand motion analysis of the Imperial College Surgical Assessment Device (ICSAD) in a simulated model of spinal anesthesia.MethodsThree groups of physicians with different levels of experience were video recorded performing a spinal anesthesia in a simulated lumbar puncture torso. Participants’ technical performance was assessed with ICSAD, a Global Rating Scale (GRS) and a specific Checklist. Differences between the 3 groups were determined by Kruskal-Wallis test with post hoc Dunn’s correction for multiple comparisons. Spearman correlation coefficient between ICSAD variables and the scores of the observational scales were calculated to establish concurrent validity.ResultsThirty subjects participated in the study: ten novice (first year residents), 10 intermediate (third year residents) and 10 experts (attending anesthesiologists). GRS scores were significantly higher in experts, than intermediates and novices. Regarding total path length, number of movements and procedural time measured with ICSAD, all groups had significant differences between them (p = 0.026, p = 0.045 and p = 0.005 respectively). Spearman correlation coefficient was −0,46 (p = 0.012) between total path length measured with ICSAD and GRS scores.ConclusionsThis is the first validation study of ICSAD as an assessment tool for spinal anesthesia in a simulated model. Using ICSAD can discriminate proficiency between expert and novices and correlates with previously validated GRS. Its use in the assessment of spinal anesthesia proficiency provides complementary data to existing tools. Our results could be used to design future training programs with reliable goals to accomplish.

Experimental study on precaution osteoporosis by the increase of cerebrospinal fluid leptin level on rabbit model

Objective To explore effect of increasing cerebrospinal fluid (CSF) leptin level by administration from the foramen magnum to the cerebellum medulla oblongata pool in osteoporosis in rabbit model established by ovariectomy (OVX) and methylprednisolones. Methods According to certain inclusion and exclusion criteria, 30 adult rabbits which were healthy 5-month-old female New Zealand white rabbits with the same batch and weight were divided into 5 groups (n=6) with random number table, including control group, normal saline group, Low dose group, middle dose group and high dose group. The animal model of osteoporosis (OP) was established 8 weeks after ovariectomy (bilateral ovarian resection) and intramuscular injection of methylprednisolone daily for 8 consecutive weeks in all groups. The control group were only simulated puncture and didn’t inject any drugs or normal saline, the normal saline group were intracerebroventricular (ICV) injection with NS and Low, Middle and High dose group injected with low, middle and high dose of leptin respectively at 0,3,7 days after OVX. Before (0 week) and 4,8 weeks after the operation, the measure of dual energy X-ray absorptiometry was done on all the rabbits femur and bone mineral density (BMD) was delivered. Before (0 week) and 4, 8 weeks after the first administration, leptin in cerebrospinal fluid (CSF) and serum growth hormone (GH), insulin growth factor 1 (IGF-1) and osteocalcin (OT/BGP) were tested with Enzyme linked immunosorbent assay and serum calcium, phosphorus and alkaline phosphatase (ALP) with automatic biochemical analyzer (ACA). The rabbits were sacrificed and the thalamus and femoral neck were harvested to test the expression of leptin receptor (LEPR) in thalamus and bone morphogenetic protein-2 (BMP-2) and typeⅠcollagen (ColⅠ) at 8 weeks after the first administration. Results Compared with the control group and NS group, the cerebrospinal fluid (CSF) leptin concentration of leptin administration groups kept in a higher level significantly at 4 and 8 weeks after leptin administration, it was positively correlated with the concentration of administration. After administration 4 and 8 weeks, the bone mineral density (BMD) of leptin administration groups were not significantly lower than that of non-administration groups, and the high dose group was unchanged. The serum osteocalcin/bone glad protein (OT/BGP) concentration of leptin administration groups decreased more significantly compared with the non-administration groups at 4 weeks after leptin administration; and it rebounded more significantly than the non-administration groups and low dose group rebounded more significantly than other non-administration groups at 8 weeks. The concentration of serum growth hormone (GH) of 5 groups showed a downward trend at 4 and 8 weeks, the serum GH concentration of leptin administration groups decreased more significantly than the non-administration groups. The concentration of serum insulin-like growth IGF-1 of 5 groups were decreased significantly at 4 weeks, and the serum IGF-1 concentration of control and low dose groups were significantly higher than other 3 groups at 8weeks. Compared with the non-administration groups, the concentration of serum Calcium of leptin administration groups were increased more obvious, and it was positively correlated with the concentration of administration. Serum phosphorus of 5 groups were decreased at 4 weeks and elevated at 8 weeks; there was no difference among the groups. Serum ALP showed a continuous downward trend, and the middle dose group decreased significantly compared with other groups at 4 and 8 weeks. RT-PCR results showed that the BMP-2 and Col ⅠmRNA expression increased and positively correlated with leptin administration concentration at 8weeks. Conclusion The increase of cerebrospinal fluid leptin level can promote the bone metabolism, reduce bone loss and precaution the occurrence of osteoporosis in rabbit model caused by OVX and methylprednisolone, and it was positively correlated with the concentration of administration. That provides a new method for the prevention and treatment of osteoporosis in rabbit model. Key words: Leptin; Osteoporosis; Bone density

Preliminary application of customized guide plate manufactured by digital and 3D printing technology in the periarticular puncture of the shoulder

Objective To study the feasibility of using the customized guide plate manufactured by digital modeling and 3D printing technology in the periarticular puncture of the shoulder. Methods Nine patients with shoulder disorder were enrolled in this study. They were 4 males and 5 females, 39 to 62 years of age (average, 56.8 years). Four cases were from Shanghai Ninth People's Hospital between May 2014 and August 2014; 5 cases were from Guizhou Provincial People's Hospital between August 2014 and October 2014. Altogether 9 shoulders were involved (3 at the left side, 6 at the right side; 8 joint cavities and one proximal humerus). Data of their lamellar CT scans were imported into Mimics15.0 for 3D anatomical modeling. We did reverse and sequential engineering throughout the software Geomagic Studio and Geomagic Spark. First the insertion points were determined after the in vitro simulated puncture in the customized percutaneous guide plate manufactured by digital modeling and 3D printing technology. Next the periarticular puncture of the shoulder was performed in the 9 patients after precise positioning and to be checked using C-arm fluoroscopy. Results In this study, the periarticular puncture of the shoulder was performed successfully in both the preoperative simulation in the skeleton model manufactured by digital modeling and 3D printing technology and the 9 patients. The positions of needling in the real operation were in total agreement with the preoperative virtual design. No puncture failure or side lesions of the vessels and nerves occurred. Conclusion The customized percutaneous guide plate manufactured by digital modeling and 3D printing technology can make the periarticular puncture of the shoulder more precise. Key words: Shoulder joint; Punctures; Tomography, spiral computed; 3D printing technology

Effect of ionic content on ballistic self-healing in EMAA copolymers and ionomers

A specific class of poly(ethylene-co-methacrylic acid) copolymers and ionomers (EMAA) possesses a unique ability to instantly self-heal following ballistic projectile puncture. The present study has comprehensively explored the relationship between ionic content, morphology and the self-healing property response to high energy impact, using a range of EMAA copolymers which vary from non-ionic to highly neutralized. DSC, DMA, FTIR and rheological methods were used to understand the thermal, rheological, chemical and microstructural responses which can occur during temperature variations experienced during high energy impact. Ballistic puncture testing probed the self-healing response over a wide range of temperatures, from −50 °C to 140 °C, allowing the production of a self-healing “phase-style diagram” identifying regions of self-healing success or failure as a function of ionic content and impact temperature. Moderate ionic content proved the most beneficial to healing for tests below the order–disorder transition (Ti = 40 °C); while above and into the melt (Tm = 90 °C) healing improved with increasing ionic content. Finally, a previously established, instrumented non-ballistic puncture method was used to record the tensile forces and displacements during a simulated puncture experiment allowing delineation of elastic vs. elastomeric (flow) properties as a function of ionic content. Overall, the relative mobility and strength of the associative regions whether arising from hydrogen bonding in the case of the non-ionic species, or ionic association in the case of the neutralized ionomers, was demonstrated to control the self-healing performance when subjected to high energy impact.

The effect of skin entry site, needle angulation and soft tissue compression on simulated antegrade and retrograde femoral arterial punctures: an anatomical study using Cartesian co-ordinates derived from CT angiography

Safe femoral arterial access is an important procedural step in many interventional procedures and variations of the anatomy of the region are well known. The aim of this study was to redefine the anatomy relevant to the femoral arterial puncture and simulate the results of different puncture techniques. A total of 100 consecutive CT angiograms were used and regions of interest were labelled giving Cartesian co-ordinates which allowed determination of arterial puncture site relative to skin puncture site, the bifurcation and inguinal ligament (ING). The ING was lower than defined by bony landmarks by 16.6 mm. The femoral bifurcation was above the inferior aspect of the femoral head in 51% and entirely medial to the femoral head in 1%. Simulated antegrade and retrograde punctures with dogmatic technique, using a 45-degree angle would result in a significant rate of high and low arterial punctures. Simulated 50% soft tissue compression also resulted in decreased rate of high retrograde punctures but an increased rate of low antegrade punctures. Use of dogmatic access techniques is predicted to result in an unacceptably high rate of dangerous high and low punctures. Puncture angle and geometry can be severely affected by patient obesity. The combination of fluoroscopy to identify entry point, ultrasound-guidance to identify the femoral bifurcation and soft tissue compression to improve puncture geometry are critical for safe femoral arterial access.