Application of stereo-imaging technology to medical field

Ergonomics in ENT Practice

The term Ergonomics is derived from two Greek words "Ergos" meaning work and "nomos" meaning laws. So, Ergonomics in simple term means "laws of work". It actually concerns with optimizing the relations between a worker and his work of environment. Ergonomics is a science that studies workplaces with the aim to optimise the interaction between the worker, equipment, task and the environment (Campbell in Ergonomics in otorhinolaryngology. Ent and audiology news, 2024) Workplace ergonomics is a poorly understood subject when it comes to medical professionals. Musculo- skeletal disorders (MSD) are one of the commonest occupational health problem for surgeons. Though, Ergonomics apply to every surgeon/medical professional, this article will in specifically discuss the importance of understanding ergonomics for ENT (otolaryngologists) surgeons.

Doing more with less: Realistic stereoscopic three-dimensional anatomical modeling from smartphone photogrammetry

Traditional teaching methods struggle to convey three-dimensional concepts effectively. While 3D virtual models and virtual reality platforms offer a promising approach to teaching anatomy, their cost and specialized equipment pose limitations, especially in disadvantaged areas. A simpler alternative is to use virtual 3D models displayed on regular screens, but they lack immersion, realism, and stereoscopic vision. To address these challenges, we developed an affordable method utilizing smartphone-based 360° photogrammetry, virtual camera recording, and stereoscopic display (anaglyph or side-by-side technique). In this study, we assessed the feasibility of this method by subjecting it to various specimen types: osteological, soft organ, neuroanatomical, regional dissection, and a dedicated 3D-printed testing phantom. The results demonstrate that the 3D models obtained feature a complete mesh with a high level of detail and a realistic texture. Mesh and texture resolutions were estimated to be approximately 1 and 0.2 mm, respectively. Additionally, stereoscopic animations were both feasible and effective in enhancing depth perception. The simplicity and affordability of this method position it as a technique of choice for creating easily photorealistic anatomical models combined with stereoscopic depth visualization.

Development of Augmented Reality Vision for Osteosynthesis Using a 3D Camera

BACKGROUND

We developed a 3D camera system to track motion in a surgical field. This system has the potential to introduce augmented reality (AR) systems non-invasively, eliminating the need for the invasive AR markers conventionally required. The present study was performed to verify the real-time tracking accuracy of this system, assess the feasibility of integrating this system into the surgical workflow, and establish its potential to enhance the accuracy and efficiency of orthopedic procedures.

METHODS

To evaluate the accuracy of AR technology using a 3D camera, a forearm bone model was created. The forearm model was depicted using a 3D camera, and its accuracy was verified in terms of the positional relationship with a 3D bone model created from previously imaged CT data. Images of the surgical field (capturing the actual forearm) were taken and saved in nine poses by rotating the forearm from pronation to supination. The alignment of the reference points was computed at the three points of CT versus the three points of the 3D camera, yielding a 3D rotation matrix representing the positional relationship. In the original system, a stereo vision-based 3D camera, with a depth image resolution of 1280×720 pixels, 30 frames per second, and a lens field of view of 64 specifications, with a baseline of 3 cm, capable of optimally acquiring real-time 3D data at a distance of 40-60 cm from the subject was used. In the modified system, the following modifications were made to improve tracking performance: (1) color filter processing was changed from HSV to RGB, (2) positional detection accuracy was modified with supporting marker sizes of 8 mm in diameter, and (3) the detection of marker positions was stabilized by calculating the marker position for each frame. Tracking accuracy was examined with the original system and modified system for the following parameters: differences in the rotation matrix, maximum and minimum inter-reference point errors between CT-based and camera-based 3D data, and the average error for the three reference points.

RESULTS

In the original system, the average difference in rotation matrices was 5.51±2.68 mm. Average minimum and maximum errors were 1.10±0.61 and 15.53±12.51 mm, respectively. The average error of reference points was 6.26±4.49 mm. In the modified system, the average difference in rotation matrices was 4.22±1.73 mm. Average minimum and maximum errors were 0.79±0.49 and 1.94±0.87 mm, respectively. The average error of reference points was 1.41±0.58 mm. In the original system, once tracking failed, it was difficult to recover tracking accuracy. This resulted in a large maximum error in supination positions. These issues were resolved by the modified system. Significant improvements were achieved in maximum errors and average errors using the modified system (P<0.05).

CONCLUSION

AR technology using a 3D camera was developed. This system allows direct comparisons of 3D data from preoperative CT scans with 3D data acquired from the surgical field using a 3D camera. This method has the advantage of introducing AR into the surgical field without invasive markers.

Extrinsic Calibration for a Modular 3D Scanning Quality Validation Platform with a 3D Checkerboard

Optical 3D scanning applications are increasingly used in various medical fields. Setups involving multiple adjustable systems require repeated extrinsic calibration between patients. Existing calibration solutions are either not applicable to the medical field or require a time-consuming process with multiple captures and target poses. Here, we present an application with a 3D checkerboard (3Dcb) for extrinsic calibration with a single capture. The 3Dcb application can register captures with a reference to validate measurement quality. Furthermore, it can register captures from camera pairs for point-cloud stitching of static and dynamic scenes. Registering static captures from TIDA-00254 to its reference from a Photoneo MotionCam-3D resulted in an error (root mean square error ± standard deviation) of 0.02 mm ± 2.9 mm. Registering a pair of Photoneo MotionCam-3D cameras for dynamic captures resulted in an error of 2.2 mm ± 1.4 mm. These results show that our 3Dcb implementation provides registration for static and dynamic captures that is sufficiently accurate for clinical use. The implementation is also robust and can be used with cameras with comparatively low accuracy. In addition, we provide an extended overview of extrinsic calibration approaches and the application's code for completeness and service to fellow researchers.

Visualisation ergonomics and robotic surgery

Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon camera control, and line of sight screen location. Other ergonomic factors relating to visualisation include stereo-acuity, vergence-accommodation mismatch, visual-perception mismatch, visual-vestibular mismatch, visuospatial ability, visual fatigue, and visual feedback to compensate for lack of haptic feedback. Visual fatigue symptoms may be related to dry eye or accommodative/binocular vision stress. Digital eye strain can be measured by questionnaires and objective tests. Management options include treatment of dry eye, correction of refractive error, and management of accommodation and vergence anomalies. Experienced robotic surgeons can use visual cues like tissue deformation and surgical tool information as surrogates for haptic feedback.

Coupling Effect Suppressed Compact Surgical Robot with 7-Axis Multi-Joint Using Wire-Driven Method

Currently, the most prevalent surgical treatment method is laparoscopic surgery. Robotic surgery has many advantages over laparoscopic surgery. Therefore, robotic surgery technology is currently constantly evolving. The advantages of robotic surgery are that it can minimize incision, bleeding, and sequelae. Other advantages of robotic surgery are that it can reduce hospitalization, recovery period, and side effects. The appeal of robotic surgery is that it requires fewer surgical personnel compared to laparoscopic surgery. This paper proposes an ultra-compact 7-axis vertical multi-joint robot that employs the wire-driven method for minimally invasive surgery. The proposed robot analyzes the degree of freedom and motion coupling for control. The robot joint is composed of a total of seven joints, and among them, the 7-axis joint operates the forceps. At this time, the forceps joint (#7 axis) can only operate open and close functions, while the link is bent and rotatable, regardless of position change. This phenomenon can be analyzed by Forward Kinematics. Also, when the DOF rotates, the passing wires become twisted, and the wire is generated through length change and coupling phenomenon. The maximum rotation angle of DOF is 90° and the rotating passing wire is wound by the rotation of the wire pulley. If the DOF is rotated to the full range of 120°, the second DOF will be rotated to 90°, and at this time, the coupling phenomenon caused by the first DOF rotation can be eliminated. The length change and the robot joint angle change related to the motor drive, based on the surgical robot control using the wire-driven method, are correlated, and the values for the position and direction of the end effector of the robot can be obtained through a forward kinematic analysis. The coupling problem occurring in the wire connecting the robot driving part can be solved through a kinematic analysis. Therefore, it was possible to test the position of the slave robot and the performance of the surgical forceps movement using the master system.

The Application of Three-Dimensional Technologies in the Improvement of Orthopedic Surgery Training and Medical Education Quality: A Comparative Bibliometrics Analysis

Orthopedics is a medical specialty that focuses on the clinical treatment and care of the musculoskeletal system. Orthopedics is a medical specialty which specializing in the clinical treatment and nursing of musculoskeletal system. The education of orthopedics is often serious and difficult because of the high technical requirements, complicated anatomical knowledge and long study process. However, medical students or junior residents rarely have the opportunity to see such orthopedic surgery or attend preclinical practice, which limits the opportunities for training clinicians. Hopefully, with the increasing use of three-dimensional (3D) technologies in medical teaching, this situation can be alleviated. In this study, we demonstrate that different 3D technologies can effectively simulate orthopedic surgery with very high accuracy. We carefully evaluated the use of 3D technologies in primary medical teaching and proposed a vision for the future. We searched and screened 3,997 publications from the Web of Science Core Collection (WoSCC) on 22 Oct 2021 with (trauma) AND ((education) OR (training) OR (teaching) OR (learning)) AND ((3D) OR (Three Dimensional)), (Joint) AND ((education) OR (training) OR (teaching) OR (learning)) AND ((3D) OR (Three Dimensional)), (spine) AND ((education) OR (training) OR (teaching) OR (learning)) AND ((3D) OR (Three Dimensional)) as the search strategy. Then, we eliminated the publications irrelevant to “orthopedics” AND/OR “orthopaedic” (in United Kingdom English), the final number of publications are 440 for trauma surgery, 716 for joint surgery and 363 for spine surgery, a visual display of comprehensive information analysis was made by VOSviewer. Next, we read and analyzed retrieved articles extensively according to the selection criteria, 11 highly cited publications on three major branches of orthopedics were chosen. The extracted data included the authors, purpose, methods, results and benefits/limitations. The evaluation of these studies directly and objectively proved the superiority of 3D technologies in orthopedics. Furthermore, the material usage and strength of 3D technologies can be closer to the real situation, which will help improve their effectiveness in teaching. We hope that more relevant studies will be conducted to continue examining the effects of 3D technologies on orthopedic medical education as well as orthopedic surgery training, and we hope that this technique can be more widely used in the clinical teaching of orthopedics to train clinicians on learning medical theory and surgical technology quickly and efficiently.

Comparison of Chief Surgeons' and Assistants' Feelings of Fatigue Between Laparoendoscopic Single-site and Conventional Laparoscopic Adrenalectomy

BACKGROUND

Our objective was to compare the surgical staff's feelings of fatigue between laparoendoscopic single-site adrenalectomy (LESS-A) and conventional laparoscopic adrenalectomy (CLA) before and after surgery.

METHOD

Data were collected for surgical procedures performed between June 2011 and September 2017 (57 LESS-A and 37 CLA). Each procedure in both groups was performed by the same chief surgeon. The subjective fatigue feelings of the key members of the surgical team (chief surgeon, scopist, assistant surgeon) were assessed using the "Jikaku-sho shirabe" questionnaire, which contained questions about work-related feelings of fatigue. It consisted of 25 subjective items for 5 factors drawn from factor analysis (drowsiness, instability, uneasiness, local pain or dullness, and eyestrain). For each item, the participants were requested to estimate the intensity of their feelings using a five-point rating scale before and after surgery.

RESULTS

There was no significant difference in operative time (p = 0.231) between the LESS-A and CLA procedure groups. For the chief surgeon, local pain or dullness (p = 0.603) and eyestrain (p = 0.086) were similar between the LESS-A and CLA procedures. The scopists and assistant surgeons in the LESS-A group did not suffer local pain or dullness (p = 0.793 and p = 0.240, respectively). They did, however, suffer more eyestrain than those in the CLA group (p = 0.001 and p = 0.001, respectively).

CONCLUSION

Although LESS-A is generally considered to be a technically difficult procedure, the results of this study demonstrate that the feelings of physical fatigue are roughly equivalent between LESS-A and CLA procedures.

Dermatologic Scar Assessment With Stereoscopic Imaging and Digital Three-Dimensional Models: A Validation Study

BACKGROUND AND OBJECTIVE

We evaluated a new handheld stereoscopic imaging system capable of visualizing scars with digital three-dimensional (3D) models and providing automated morphometric estimates. The objective was to validate the repeatability and accuracy of intra- and inter-investigator scan results.

STUDY DESIGN/MATERIALS AND METHODS

Engineered metal plates with depressed and elevated model scars (n = 72) were scanned six times by one investigator. In vivo hypertrophic and atrophic scars (n = 15) were scanned once by three investigators. The repeatability of morphometric estimates was assessed using coefficients of variation (CVs) to compare the variation among multiple scan results for both models and in vivo scars, with 0% reflecting a perfect match. Scar estimates from digital 3D reconstructions were compared with the known dimensions of physical model scars and with ruler measurements of in vivo scars.

RESULTS

A total of 48 model scars and 12 in vivo scars were eligible for automated analyses with the imaging system's proprietary software. Intra-investigator scan results for the model scars were repeatable, with low variance for all parameters: volume, area, length, and depth/height (CV: 1.8-3.1%). By comparison, inter-investigator scans of real in vivo scars resulted in slightly higher median CVs (4.4-7.3%; P < 0.05). 3D model scar estimates correlated well with the known physical dimensions of model scars for all parameters (P < 0.001) and accurately reflected the measurements of in vivo scars (P < 0.001). The six in vivo scars situated on the chest and abdomen showed the highest inter-investigator variation, due to respiratory movement artifacts.

CONCLUSION

Stereoscopic imaging of scars generates accurate and repeatable measurement estimates that show little intra- and inter-investigator-based assessment variation. The best results are achieved by minimizing subject movement. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Clinical Study of Three-Dimensional Laparoscopic Partial Nephrectomy for the Treatment of Highly Complex Renal Tumors with RENAL Nephrometry Scores of ≥10 Points

Aims

To examine the safety and feasibility of three-dimensional (3-D) laparoscopic partial nephrectomy for clinically complex renal tumors.

Materials and Methods

We retrospectively evaluated 76 patients who underwent a 3-D (n = 42; age, 54.6 ± 12.2 years) or two-dimensional (2-D) laparoscopic partial nephrectomy (n = 34; age, 54.8 ± 13.2 years) for renal tumors with RENAL nephrectomy scores of ≥10 points from the same surgical group between January 2017 and April 2020 in Ningbo Urology and Nephrology Hospital. Mean tumor diameter, operation time, warm ischemic time, amount of intraoperative blood loss, postoperative hospitalization time, hospitalization cost, perioperative complication rate, and renal function were compared.

Results

The operation time (154.6 ± 45.1 min) and warm ischemic time (22.5 ± 6.8 min) in the 3-D laparoscopic group were significantly lower than those in the 2-D laparoscopic group (193.0 ± 59.2 min, p = 0.001 and 28.7 ± 7.8 min, p = 0.0002, respectively). No significant differences in amount of intraoperative blood loss (p = 0.642), length of postoperative hospital stay (p = 0.541), perioperative complication rate (p = 0.860), total hospital cost (p = 0.641), and renal function changes including estimated glomerular filtration rate and serum creatinine (p > 0.05) were found between the two groups.

Conclusion

Our preliminary experience showed that the 3-D laparoscopic imaging system significantly shortened the operation and renal ischemic times, which are more conducive to partial resection of highly complex renal tumors.

Stereoscopic Images from Computed Tomography Angiograms

OBJECTIVE

To present an adaptation of the anaglyph photography technique to be used with radiological images from computed tomography angiograms, enabling stereoscopic visualization of a patient's individual abnormal vascular anatomy for teaching, case discussion, or surgical planning purposes.

METHODS

Traditional anaglyph procedures with actual objects yield 2 independent photographs, simulating the image perceived by each eye. Production of anaglyphs from angiograms involve 3 basic procedures: volume rendering, image capture, and image fusion. Volume renderings were reconstructed using a free, open-source DICOM (Digital Imaging and Communications in Medicine) reader. Subsequently, the virtual object was positioned to mimic the operator's angle of view, and different perspectives of the reconstructed volume could be obtained through exclusively horizontal rotation. The 2 images were then fused after their color composition was modified so that each eye would perceive only 1 image when using anaglyph glasses.

RESULTS

Forty-three angiograms were reviewed for the purpose of this study and a total of 6 examinations were selected for illustration of the technique. Stereoscopic display was possible for all of them and in the 3 types of support tested: computer monitor, tablet, and smartphone screens.

CONCLUSIONS

Anaglyph display of computed tomography angiograms is an effective and low-cost alternative for the stereoscopic visualization of a patient's individual intracranial vascular anatomy.

Comparison of 3-Dimensional and Augmented Reality Kidney Models With Conventional Imaging Data in the Preoperative Assessment of Children With Wilms Tumors

IMPORTANCE

Nephron-sparing surgery can be considered in well-defined cases of unilateral and bilateral Wilms tumors, but the surgical procedure can be very challenging for the pediatric surgeon to perform.

OBJECTIVE

To assess the added value of personalized 3-dimensional (3-D) kidney models derived from conventional imaging data to enhance preoperative surgical planning.

DESIGN, SETTING, AND PARTICIPANTS

In a survey study, the conventional imaging data of 10 Dutch children with Wilms tumors were converted to 3-D prints and augmented reality (AR) holograms and a panel of pediatric oncology surgeons (n = 7) assessed the quality of the different imaging methods during preoperative evaluation. Kidney models were created with 3-D printing and AR using a mixed reality headset for visualization.

MAIN OUTCOMES AND MEASURES

Differences in the assessment of 4 anatomical structures (tumor, arteries, veins, and urinary collecting structures) using questionnaires. A Likert scale measured differences between the imaging methods, with scores ranging from 1 (completely disagree) to 5 (completely agree).

RESULTS

Of the 10 patients, 7 were girls, and the mean (SD) age was 3.7 (1.7) years. Compared with conventional imaging, the 3-D print and the AR hologram models were evaluated by the surgeons to be superior for all anatomical structures: tumor (median scores for conventional imaging, 4.07; interquartile range [IQR], 3.62-4.15 vs 3-D print, 4.67; IQR, 4.14-4.71; P = .008 and AR hologram, 4.71; IQR, 4.26-4.75; P = .002); arteries (conventional imaging, 3.62; IQR, 3.43-3.93 vs 3-D print, 4.54; IQR, 4.32-4.71; P = .002 and AR hologram, 4.83; IQR, 4.64-4.86; P < .001), veins (conventional imaging, 3.46; IQR 3.39-3.62 vs 3-D print, 4.50; IQR, 4.39-4.68; P < .001 and AR hologram, 4.83; IQR, 4.71-4.86; P < .001), and urinary collecting structures (conventional imaging, 2.76; IQR, 2.42-3.00 vs 3-D print, 3.86; IQR, 3.64-4.39; P < .001 and AR hologram, 4.00; IQR, 3.93-4.58; P < .001). There were no differences in anatomical assessment between the two 3-D techniques (the 3-D print and AR hologram).

CONCLUSIONS AND RELEVANCE

In this study, the 3-D kidney models were associated with improved anatomical understanding among the surgeons and can be helpful in future preoperative planning of nephron-sparing surgery for Wilms tumors. These models may be considered as a supplementary visualization in clinical care.

Realization of real-time X-ray stereoscopic vision during interventional procedures

During interventional procedures, the deficiencies of nonstereoscopic vision increase the difficulty of identifying the anteroposterior direction and pathways of vessels. Therefore, achieving real-time stereoscopic vision during interventional procedures is meaningful. Pairs of X-ray images were captured with identical parameter settings, except for different rotation angles (represented as the α angle). The resulting images at these α angles were used as left-eye and right-eye views and were horizontally merged into single left-right 3D images. Virtual reality (VR) glasses were used for achieving stereo vision. Pairs of X-ray images from four angiographies with different α angles (1.8-3.4°) were merged into left-right 3D images. Observation with VR glasses can produce realistic stereo views of vascular anatomical structure. The results showed that the optimal α angles accepted by the brain for generating stereo vision were within a narrow range (approximately 1.4-4.1°). Subsequent tests showed that during transcatheter arterial chemoembolization, 3D X-ray stereoscopic images provided significantly improved spatial discrimination and convenience for identifying the supply vessels of a liver tumor and its anteroposterior direction compared with plain X-ray images (all P < 0.01). Real-time X-ray stereoscopic vision can be easily achieved via the straightforward method described herein and has the potential to benefit patients during interventional procedures.

Stereoscopic digital mammogram: Usefulness in daily practice

OBJECTIVES

To assess the benefit of stereoscopic digital mammography in daily practice.

METHODS

Stereoscopic digital (SD) mammography allows a fused 3D view of mammogram. A 4-degree cranio-caudal (CC) angle view matched with a regular CC view allows generating a stereoscopic view. Three breast radiologists reviewed retrospectively 1110 stereoscopic digital mammograms (1075 women) performed between November 2011 and February 2013 with the following sequence: each evaluated firstly conventional mammogram alone, and then integrated SD mammograms. The benefit was quoted in 3-grade scale: 0 for no benefit, 1 moderate and 2 excellent. The concordance between radiologists was evaluated by the W Randall coefficient. Subgroup analysis according to the BI-RADS classification, breast density and type of abnormalities were performed by calculating odds-ratio.

RESULTS

The readers had the same opinion regarding the value of stereoscopic digital mammograms in 87% of cases (962/1110). Benefit was null, moderate and excellent in 8, 52 and 26% respectively. The concordance of radiologists was excellent with a W coefficient above 0.89.

CONCLUSIONS

SD mammogram improved interpretation of abnormal mammograms. This potentially interesting and promising complementary tool might be beneficial in daily breast imaging practice.

A mixed reality approach for stereo-tomographic quantification of lung nodules

To reduce the radiation dose and the equipment cost associated with lung CT screening, in this paper we propose a mixed reality based nodule measurement method with an active shutter stereo imaging system. Without involving hundreds of projection views and subsequent image reconstruction, we generated two projections of an iteratively placed ellipsoidal volume in the field of view and merging these synthetic projections with two original CT projections. We then demonstrated the feasibility of measuring the position and size of a nodule by observing whether projections of an ellipsoidal volume and the nodule are overlapped from a human observer's visual perception through the active shutter 3D vision glasses. The average errors of measured nodule parameters are less than 1 mm in the simulated experiment with 8 viewers. Hence, it could measure real nodules accurately in the experiments with physically measured projections.

Stereomicroscopic 3D-pattern profiling of murine and human intestinal inflammation reveals unique structural phenotypes

Histology is fundamental to assess two-dimensional intestinal inflammation; however, inflammatory bowel diseases (IBDs) are often indistinguishable microscopically on the basis of mucosal biopsies. Here, we use stereomicroscopy (SM) to rapidly profile the entire intestinal topography and assess inflammation. We examine the mucosal surface of >700 mice (encompassing >16 strains and various IBD-models), create a profiling catalogue of 3D-stereomicroscopic abnormalities and demonstrate that mice with comparable histological scores display unique sub-clusters of 3D-structure-patterns of IBD pathology, which we call 3D-stereoenterotypes, and which are otherwise indiscernible histologically. We show that two ileal IBD-stereoenterotypes ('cobblestones' versus 'villous mini-aggregation') cluster separately within two distinct mouse lines of spontaneous ileitis, suggesting that host genetics drive unique and divergent inflammatory 3D-structural patterns in the gut. In humans, stereomicroscopy reveals 'liquefaction' lesions and hierarchical fistulous complexes, enriched with clostridia/segmented filamentous bacteria, running under healthy mucosa in Crohn's disease. We suggest that stereomicroscopic (3D-SMAPgut) profiling can be easily implemented and enable the comprehensive study of inflammatory 3D structures, genetics and flora in IBD.