In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.
ObjectiveCT three-dimensional reconstruction technology was used to simulate the placement of the lumbar cortical bone trajectory (CBT), to determine the starting point and direction of the screw trajectory.MethodsBetween February 2017 and April 2018, 24 patients with lumbar CT were selected as the study object. There were 7 males and 17 females, with an average age of 50.4 years (range, 37-68 years). The CT DICOM data of patients were imported into Mimics 16.0 software, and the three-dimensional model of lumbar spine was established. A 5 mm diameter cylinder was set up to simulate the CBT by using Mimics 16.0 software. According to the different implant schemes, the study was divided into groups A, B, and C, the track of the screw respectively passed through the upper edge, the medial edge, and the lower edge of the isthmus of the pedicle. The intersection of simulated screw and lumbar spine was marked as region of interest (ROI) and a mask was generated. The average CT value [Hounsfield unit (HU)] and the screw length of ROI were automatically measured by Mimics 16.0 software. In addition, the head inclination angle and head camber angle of the screw were measured respectively. Point F was the intersection of the level of the lowest edge of the transverse process and the lumbar isthmus periphery. The horizontal and vertical distance between point F and the starting point were measured, and the relationship between the three schemes and the position of the zygapophysial joint and spinous process was observed.ResultsPlan A has the highest ROI average HU, with the maximum value appearing in L4; plan B has the longest screw length, with the maximum value appearing in L5; plan C has the largest nail track head inclination angle, with the maximum value appearing in L4; plan B has the largest nail track head camber angle, with the maximum value appearing in L3. The screw length and head camber angle of the nail in group B were significantly greater than those in groups A and C (P<0.05); the head inclination angle in groups A, B, and C was gradually increased, showing significant differences (P<0.05); there was no significant difference in the average HU value of ROI between the 3 groups (P>0.05). In plan A, 74.48% (143/192) screws had a horizontal distance of −2 to 4 mm from point F, a vertical distance of 6-14 mm from point F, a head inclination angle of (14.64±2.77)°, and a head camber angle of (6.55±2.09)°, respectively; in plan B, 84.58% (203/240) screws had a horizontal distance of 1-6 mm from point F, a vertical distance of 1-5 mm from point F, a head inclination angle of (26.93±2.21)°, and a head camber angle of (10.29±2.46)°, respectively; in plan C, 85.94% (165/192) screws had a horizontal distance of −2 to 3 mm from point F, a vertical distance of −2 to 4 mm from point F, a head inclination angle of (33.50±3.69)°, and a head camber angle of (6.47±2.48)°, respectively.ConclusionPlan B should be selected as the starting point of the L1-L5 CBT implant. It is located at the intersection of the lowest horizontal line of the transverse process root and the lateral edge of the lumbar isthmus, which is 1-6 mm horizontally inward, 1-5 mm vertically upward, with a head inclination angle of (26.93±2.21)°, and a head camber angle of (10.29±2.46)°, respectively.
ObjectiveTo evaluate myocardial segmental motion function in left ventricular of patients with rheumatic mitral stenosis by using the technology of real-time three-dimensional echocardiography (RT-3DE). MethodsWe retrospectively analyzed the clinical data of 14 patients with rheumatic mitral stenosis between October and November 2014 in our hospital as a trial group. There were 4 males and 10 females with a mean age of 50.9±9.0 years ranging from 34 to 64 years. We chose 11 healthy individuals as a control group. There were 7 males and 4 females with a mean age of 49.5±9.7 years ranging from 32 to 67 years. Both the two groups were subjected to myocardial performance evaluation using two-dimensional echocardiography (2DE) and real-time three-dimensional echocardiography (RT-3DE) to examine the left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), longitudinal strain, circumferential strain, area strain, and lateral strain of each left ventricular myocardial segments. Result RT-3DE detected that the trial group had significantly lower values of LVEF, LVEDV and LVESV than those of the control group (P < 0.05). RT-3DE also revealed that the trial group had a significantly weaker longitudinal strain than the control group (P < 0.05). ConclusionRT-3DE is an accurate technology for assessing myocardial motion and function in patients with rheumatic mitral valve disease.
Objective To explore the effectiveness and predictive value of computer simulated thoracic endovascular aortic repair (TEVAR). Methods The clinical data of the patients with Stanford type B aortic dissection who underwent TEVAR from February 2019 to February 2022 in our hospital was collected. According to whether there was residual false cavity around the stent about 1 week after TEVAR, the patients were divided into a false cavity closure group and a false cavity residual group. Based on computer simulation, personalized design and three-dimensional construction of the stent framework and covering were carried out. After the stent framework and membrane were assembled, they were pressed and placed into the reconstructed aortic dissection model. TEVAR computer simulation was performed, and the simulation results were analyzed for hemodynamics to obtain the maximum blood flow velocity and maximum wall shear stress at the false lumen outlet level at the peak systolic velocity of the ventricle, which were compared with the real hemodynamic data of the patient after TEVAR surgery. The impact of hemodynamics on the residual false lumen around the stent in the near future based on computer simulation of hemodynamic data after TEVAR surgery was further explored. Results Finally a total of 28 patients were collected, including 24 males and 4 females aged 53.390±11.020 years. There were 18 patients in the false cavity closure group, and 10 patients in the false cavity residual group. The error rate of shear stress of the distal decompression port of the false cavity after computer simulation TEVAR was 6%-25%, and the error rate of blood flow velocity was 3%-31%. There was no statistical difference in age, proportion of male, history of hypertension, history of diabetes, smoking history, prothrombin time or activated partial thromboplatin time at admission between the two groups (all P>0.05). The blood flow velocity and shear stress after TEVAR were statistically significant (all P<0.05). The maximum shear stress (OR=1.823, P=0.010) of the false cavity at the level of the distal decompression port after simulated TEVAR was an independent risk factor for the residual false cavity around the stent. Receiver operating characteristic curve analysis showed that the area under the curve corresponding to the maximum shear stress of false cavity at the level of distal decompression port after simulated TEVAR was 0.872, the best cross-sectional value was 8.469 Pa, and the sensitivity and specificity were 90.0% and 83.3%, respectively. Conclusion Computers can effectively simulate TEVAR and perform hemodynamic analysis before and after TEVAR surgery through simulation. Maximum shear stress at the decompression port of the distal end of the false cavity is an independent risk factor for the residual false cavity around the stent. When it is greater than 8.469 Pa, the probability of residual false cavity around the stent increases greatly.
ObjectiveTo introduce the application of mixed reality technique to the preoperative and intraoperative pulmonary nodules surgery.MethodsOne 49-year female patient with multiple nodules in both lobes of the lung who finally underwent uniportal thoracoscopic resection of superior segment of left lower lobe and wedge resection of left upper lobe was taken as an example. The Mimics medical image post-processing software was used to reconstruct the patient's lung image based on the DICOM data of the patient's chest CT image before the surgery. The three-dimensional reconstructed image data was imported into the HoloLens glasses, and the preoperative discussions were conducted with the assistance of mixed reality technology to formulate the surgical methods, and the preoperative conversation with the patients was also conducted. At the same time, mixed reality technology was used to guide the surgery in real time.ResultsMixed reality technology can clearly pre-show the important anatomical structures of blood vessels, trachea, lesions and their positional relationship. With the help of mixed reality technology, the operation went smoothly. The total operation time was 49 min, the precise dorsal resection time was 27 min, and the intraoperative blood loss was about 39 mL. The patient recovered well and was discharged from hospital smoothly after surgery.ConclusionMixed reality technology has certain application value before and during the surgery for pulmonary nodules. The continuous maturity of this technology and its further application in clinics will not only bring a new direction to the development of thoracic surgery, but also provide a wide prospect.
Objective To detect the value of three-dimensional (3D) ultrasound diagnosis in common ocular fundus diseases. Methods Two-dimensional (2D) images of 38 patients with common ocular fundus diseases were three-dimensionally reconstructed via 3D ultrasound workstation. The 3D images reflecting the ocular diseases were analyzed. Result In 38 patients with common ocular fundus diseases, there was vitreous hemorrhage in 16 patients, retinal detachment in 12, choroidal detachment in 5, and intraocular space occupying lesion in 5. Compared with the 2D images, 3D reconstructed images reflect the lesions more intuitionistically, displayed the relationship between the lesions and the peripheral tissues more clearly, and revealed the blood flow more specifically. During a scanning examination, 3D reconstructed technology provided the diagnostic information of section of X, Y and Z axises simultaneously which shortened the time of examination; the condition of any point of lesions and the relation between the lesion and the peripheral tissues could be gotten by the tools like cut and chop provided by 3D imaging software itself, which avoided detecting the same lesion with different angles and lays and proved the diagnostic efficacy. Conclusions 3D ultrasound diagnosis is better than 2D in diagnosis of vitreous, retina, choroid, and intraocular space occupying lesion. 3D ultrasound diagnosis is a complementarity for the 2D one, and the Z axis changes the former observational angles which may provide the new way of precise diagnosis. (Chin J Ocul Fundus Dis, 2005, 21: 381-383)
Collagen is a kind of natural biomedical material and collagen based three-dimensional porous scaffolds have been widely used in skin tissue engineering. However, these scaffolds do not meet the requirements for artificial skin substitutes in terms of their poor mechanical properties, short supply, and rejection in the bodies. All of these factors limit their further application in skin tissue engineering. A variety of methods have been chosen to meliorate the situation, such as cross linking and blending other substance for improving mechanical properties. The highly biomimetic scaffolds either in structure or in function can be prepared through culturing cells and loading growth factors. To avoid the drawbacks of unsafety attributing to animals, investigators have fixed their eyes on the recombinant collagen. This paper reviews the the progress of research and application of collagen-based 3-dimensional porous scaffolds in skin tissue engineering.
ObjectiveTo propose a lung artery segmentation method that integrates shape and position prior knowledge, aiming to solve the issues of inaccurate segmentation caused by the high similarity and small size differences between the lung arteries and surrounding tissues in CT images. MethodsBased on the three-dimensional U-Net network architecture and relying on the PARSE 2022 database image data, shape and position prior knowledge was introduced to design feature extraction and fusion strategies to enhance the ability of lung artery segmentation. The data of the patients were divided into three groups: a training set, a validation set, and a test set. The performance metrics for evaluating the model included Dice Similarity Coefficient (DSC), sensitivity, accuracy, and Hausdorff distance (HD95). ResultsThe study included lung artery imaging data from 203 patients, including 100 patients in the training set, 30 patients in the validation set, and 73 patients in the test set. Through the backbone network, a rough segmentation of the lung arteries was performed to obtain a complete vascular structure; the branch network integrating shape and position information was used to extract features of small pulmonary arteries, reducing interference from the pulmonary artery trunk and left and right pulmonary arteries. Experimental results showed that the segmentation model based on shape and position prior knowledge had a higher DSC (82.81%±3.20% vs. 80.47%±3.17% vs. 80.36%±3.43%), sensitivity (85.30%±8.04% vs. 80.95%±6.89% vs. 82.82%±7.29%), and accuracy (81.63%±7.53% vs. 81.19%±8.35% vs. 79.36%±8.98%) compared to traditional three-dimensional U-Net and V-Net methods. HD95 could reach (9.52±4.29) mm, which was 6.05 mm shorter than traditional methods, showing excellent performance in segmentation boundaries. ConclusionThe lung artery segmentation method based on shape and position prior knowledge can achieve precise segmentation of lung artery vessels and has potential application value in tasks such as bronchoscopy or percutaneous puncture surgery navigation.
ObjectiveTo compare the three-dimensional (3D) laparoscopic simulator with two-dimensional (2D) laparoscopic simulator in training of laparoscopic novices.MethodsBetween January 2018 and December 2019, surgical residents from Chinese PLA General Hospital were enrolled, which were grouped into 3D and 2D group. After receiving training program, novices in both two groups subject to performance examination, including bean-picking module, exchange module, transfer module, needle-manipulating module, and suture module. Times and errors were compared between the two groups for each module.ResultsA total of 16 novices in 3D group and 15 novices in 2D group were enrolled, and baseline characteristics including age, gender, major hand, glass wearing, laparoscopic experience, and shooting game experience were well balanced between the two groups (P>0.05). There were comparable times and errors between the two groups in terms of bean-picking module and exchange module (P>0.05). The time of transfer module and needle-manipulating module was not significant between the two groups (P>0.05), but novices in 3D group performed more precise than those in 2D group (P<0.05). In suture module, 3D group had shorter time (P=0.02) and higher accuracy (P=0.03).Conclusion3D laparoscopic simulator can shorten novice performance time in complex procedures, improve accuracy, and facilitate laparoscopic training.
ObjectiveTo summarize the research progress of tissue engineering technology to promote bone tissue revascularization in osteonecrosis of the femoral head (ONFH).MethodsThe relevant domestic and foreign literature in recent years was extensively reviewed. The mechanism of femoral head vascularization and the application progress of tissue engineering technology in the promotion of ONFH bone tissue revascularization were summarized.ResultsRebuilding or improving the blood supply of the femoral head is the key to the treatment of ONFH. Tissue engineering is a hot spot in current research. It mainly focuses on the three elements of seed cells, scaffold materials, and angiogenic growth factors, combined with three-dimensional printing technology and drug delivery systems to promote the revascularization of the femoral bone tissue.ConclusionThe strategy of revascularization of the femoral head can improve the local blood supply and delay or even reverse the progression of ONFH disease.