Image segmentation is one of the most important tasks in medical image analysis and is often the first and the most critical step in many clinical applications. In brain MRI analysis, image segmentation is commonly used for measuring and visualizing the brain’s anatomical structures, for analyzing brain changes, for delineating pathological regions, and for surgical planning and image-guided interventions. In the last few decades, various segmentation techniques of different accuracy and degree of complexity have been developed and reported in the literature. In this paper we review the most popular methods commonly used for brain MRI segmentation. We highlight differences between them and discuss their capabilities, advantages, and limitations. To address the complexity and challenges of the brain MRI segmentation problem, we first introduce the basic concepts of image segmentation. Then, we explain different MRI preprocessing steps including image registration, bias field correction, and removal of nonbrain tissue. Finally, after reviewing different brain MRI segmentation methods, we discuss the validation problem in brain MRI segmentation.

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MRI Segmentation of the Human Brain: Challenges, Methods, and Applications

http://faratarjome.ir/u/media/shopping_files/store-EN-1427726230-2655.pdf

Integrating spatial fuzzy clustering with level set methods for automated medical image segmentation

Described herein are an apparatus and methods for automating subtasks in surgery and interventional medical procedures. The apparatus consists of a robotic positioning platform, an operating system with automation programs, and end-effector tools to carry out a task under supervised autonomy. The operating system executes an automation program, based on one or a fusion of two or more imaging modalities, guides real-time tracking of mobile and deformable targets in unstructured environment while the end-effector tools execute surgical interventional subtasks that require precision, accuracy, maneuverability and repetition. The apparatus and methods make these medical procedures more efficient and effective allowing a wider access and more standardized outcomes and improved safety.

Automated surgical and interventional procedures

Introduction. The development augmented reality devices allow physicians to incorporate data visualization into diagnostic and treatment procedures to improve work efficiency, safety, and cost and to enhance surgical training. However, the awareness of possibilities of augmented reality is generally low. This review evaluates whether augmented reality can presently improve the results of surgical procedures. Methods. We performed a review of available literature dating from 2010 to November 2016 by searching PubMed and Scopus using the terms “augmented reality” and “surgery.” Results. The initial search yielded 808 studies. After removing duplicates and including only journal articles, a total of 417 studies were identified. By reading of abstracts, 91 relevant studies were chosen to be included. 11 references were gathered by cross-referencing. A total of 102 studies were included in this review. Conclusions. The present literature suggest an increasing interest of surgeons regarding employing augmented reality into surgery leading to improved safety and efficacy of surgical procedures. Many studies showed that the performance of newly devised augmented reality systems is comparable to traditional techniques. However, several problems need to be addressed before augmented reality is implemented into the routine practice.

https://downloads.hindawi.com/journals/jhe/2017/4574172.pdf

Recent Development of Augmented Reality in Surgery: A Review

A medical robot system, including a robot coupled to an effectuator element with the robot configured for controlled movement and positioning. The system may include a transmitter configured to emit one or more signals, and the transmitter is coupled to an instrument coupled to the effectuator element. The system may further include a motor assembly coupled to the robot and a plurality of receivers configured to receive the one or more signals emitted by the transmitter. A control unit is coupled to the motor assembly and the plurality of receivers, and the control unit is configured to supply one or more instruction signals to the motor assembly. The instruction signals can be configured to cause the motor assembly to selectively move the effectuator element and is further configured to (i) calculate a position of the at least one transmitter by analysis of the signals received by the plurality of receivers; (ii) display the position of the at least one transmitter with respect to the body of the patient; and (iii) selectively control actuation of the motor assembly in response to the signals received by the plurality of receivers.

Surgical robot platform

Single-incision laparoscopic cholecystectomy (SILC) has been increasingly performed recently. Although it seems plausible that SILC will be associated with less pain compared to standard 4-port laparoscopic cholecystectomy (LC), there is currently no conclusive comparative study on the postoperative pain issues of SILC against LC. In this retrospective, case–control study, 30 patients who had SILC over a 6-month period were compared with a matched (sex, age group, race) group of 30 patients who underwent LC. Verbal pain score (VPS) on postoperative days (POD) 1, 2, 3, and 5; pain sites; analgesic requirement; and number of days (NoD) required to return to normal activities were compared. There were 4 (13%) acute cholecystitis cases in each group. Average VPS on POD 1, 2, 3, and 5 of SILC and (LC) cholecystectomy patients were 4.53 (5.14) (P = 0.09), 3.43 (3.83) (P = 0.36), 2.07 (2.52) (P = 0.25), and 1.13 (1.24) (P = 0.69), respectively. In the SILC group, 26 patients (87%) had umbilical pain, whereas in the LC group, 25 patients (83%) had similar symptoms. Epigastric pain was experienced by 5 patients in the two groups, and RHC pain was experienced by 1 patient in the SILC group (3%) and 2 patients in the LC group (7%). The SILC and the LC patients required 4.00 and 4.90 days (P = 0.09) of paracetamol, respectively, to control pain. The NoD required before return to normal activity in the SILC and LC groups was 5.97 days and 7.79 days (P = 0.008), respectively. There was no statistically significant difference in postoperative pain, pain site and analgesia requirement; however, patients who underwent SILC returned to their normal activity 1.8 days earlier than the LC patients. Larger RCTs are needed to compare postoperative outcomes between SILC and LC.

A Case–control Study of Single-Incision Versus Standard Laparoscopic Cholecystectomy

An interactive surgical simulation system needs to meet three main requirements, speed, accuracy, and stability. In this paper, we present a stable and accurate method for animating mass–spring systems in real time. An integration scheme derived from explicit integration is used to obtain interactive realistic animation for a multiobject environment. We explore a predictor–corrector approach by correcting the estimation of the explicit integration in a poststep process. We introduce novel constraints on positions into the mass–spring model (MSM) to model the nonlinearity and preserve volume for the realistic simulation of the incompressibility. We verify the proposed MSM by comparing its deformations with the reference deformations of the nonlinear finite-element method. Moreover, experiments on porcine organs are designed for the evaluation of the multiobject deformation. Using a pair of freshly harvested porcine liver and gallbladder, the real organ deformations are acquired by computed tomography and used as the reference ground truth. Compared to the porcine model, our model achieves a $1.502$ mm mean absolute error measured at landmark locations for cases with small deformation (the largest deformation is $49.109$ mm) and a $3.639$ mm mean absolute error for cases with large deformation (the largest deformation is $83.137$ mm). The changes of volume for the two deformations are limited to $0.030\%$ and $0.057\%$ , respectively. Finally, an implementation in a virtual reality environment for laparoscopic cholecystectomy demonstrates that our model is capable to simulate large deformation and preserve volume in real-time calculations.

Volume Preserved Mass–Spring Model with Novel Constraints for Soft Tissue Deformation

A robotic system for overlapping radiofrequency ablation (RFA) in tumor treatment is disclosed. The robot assisted navigation system is formed of a robotic manipulator and a control system designed to execute preoperatively planned needle trajectories. Preoperative imaging and planning is followed by interoperative robot execution of the ablation treatment plan. The navigation system combines mechanical linkage sensory units with an optical registration system. There is no requirement for bulky hardware installation or computationally demanding software modules. Final position of the first needle placement is confirmed for validity with the plan and then is used as a reference for the subsequent needle insertions and ablations.

Transcutaneous robot-assisted ablation-device insertion navigation system

Overlapping radiofrequency ablation (RFA) in large tumor treatment requires multiple insertions of electrodes, which often compromise its efficacy and predictability. Surgical robot is a promising candidate for the execution of multiple RFA in large tumor treatment in terms of accuracy and speed. In this paper, we share our experience of design and implementation of a novel robotic system specialized for overlapping RFA. It consists of two components: a robotic manipulator and an automatic ablation planning module. The manipulator architecture is designed to facilitate the kinematic requirement for the multiple overlapping ablation technique within the constraints of minimally invasive surgery. An efficient “Voxel Growing” algorithm is adopted to automatically produce the ablation points according to the tumor's profile. The feasibility of the proposed robotic system is demonstrated by extensive simulation- and experiment-based evaluation conducted on ex vivo porcine liver.

Stephen Chang

Papers

Integrating spatial fuzzy clustering with level set methods for automated medical image segmentation

A Case–control Study of Single-Incision Versus Standard Laparoscopic Cholecystectomy

Volume Preserved Mass–Spring Model with Novel Constraints for Soft Tissue Deformation

Transcutaneous robot-assisted ablation-device insertion navigation system

A Robotic System for Overlapping Radiofrequency Ablation in Large Tumor Treatment