影像引导经皮穿刺治疗机器人系统:经皮穿刺过程中位置和姿态的运动解耦

研制了一种影像引导经皮穿刺治疗机器人系统,该系统可用于超声或CT引导的穿刺活检、消融治疗及冷冻治疗及其他基于穿刺的操作.首先对穿刺操作进行分析,然后设计并制造了一个模块化机器人,该机器人可以在一定空间内辅助完成穿刺活检或针式治疗器械的置入.该机器人的主要特点是将经皮穿刺过程中位置和姿态的运动解耦,因此位置和姿态的调整可以由机器人的不同机构单独完成.这种设计的主要优势是更好地保障患者的安全.     

Automatic planning of needle placement for robot-assisted percutaneous procedures

Purpose

Percutaneous procedures allow interventional radiologists to perform diagnoses or treatments guided by an imaging device, typically a computed tomography (CT) scanner with a high spatial resolution. To reduce exposure to radiations and improve accuracy, robotic assistance to needle insertion is considered in the case of X-ray guided procedures. We introduce a planning algorithm that computes a needle placement compatible with both the patient’s anatomy and the accessibility of the robot within the scanner gantry.

Methods

Our preoperative planning approach is based on inverse kinematics, fast collision detection, and bidirectional rapidly exploring random trees coupled with an efficient strategy of node addition. The algorithm computes the allowed needle entry zones over the patient’s skin (accessibility map) from 3D models of the patient’s anatomy, the environment (CT, bed), and the robot. The result includes the admissible robot joint path to target the prescribed internal point, through the entry point. A retrospective study was performed on 16 patients datasets in different conditions: without robot (WR) and with the robot on the left or the right side of the bed (RL/RR).

Results

We provide an accessibility map ensuring a collision-free path of the robot and allowing for a needle placement compatible with the patient’s anatomy. The result is obtained in an average time of about 1 min, even in difficult cases. The accessibility maps of RL and RR covered about a half of the surface of WR map in average, which offers a variety of options to insert the needle with the robot. We also measured the average distance between the needle and major obstacles such as the vessels and found that RL and RR produced needle placements almost as safe as WR.

Conclusion

The introduced planning method helped us prove that it is possible to use such a “general purpose” redundant manipulator equipped with a dedicated tool to perform percutaneous interventions in cluttered spaces like a CT gantry.

     

Navigated CT‐guided interventions

Diagnostic and therapeutic CT‐ guided percutaneous interventions are clinical routine in interventional radiology. Image‐guided navigation systems visualize the internal anatomy during interventions in real time not necessitating continuous image acquisition. Although multiple 3D image‐guidance devices have been developed and used by several surgical disciplines in the last few years, they have not yet been fully applied by the interventional radiologist. The aim of this article is to review the currently performed methods of CT‐guided percutaneous interventions and to discuss the potential benefits of newly developed 3D‐ navigation systems.     

Toward adaptive stereotactic robotic brachytherapy for prostate cancer: Demonstration of an adaptive workflow incorporating inverse planning and an MR stealth robot

Abstract

To translate any robot into a clinical environment, it is critical that the robot can seamlessly integrate with all the technology of a modern clinic. MRBot, an MR-stealth brachytherapy delivery device, was used in a closed-bore 3T MRI and a clinical brachytherapy cone beam CT suite. Targets included ceramic dummy seeds, MR-Spectroscopy-sensitive metabolite, and a prostate phantom. Acquired DICOM images were exported to planning software to register the robot coordinates in the imager's frame, contour and verify target locations, create dose plans, and export needle and seed positions to the robot. The coordination of each system element (imaging device, brachytherapy planning system, robot control, robot) was validated with a seed delivery accuracy of within 2 mm in both a phantom and soft tissue. An adaptive workflow was demonstrated by acquiring images after needle insertion and prior to seed deposition. This allows for adjustment if the needle is in the wrong position. Inverse planning (IPSA) was used to generate a seed placement plan and coordinates for ten needles and 29 seeds were transferred to the robot. After every two needles placed, an image was acquired. The placed seeds were identified and validated prior to placing the seeds in the next two needles. The ability to robotically deliver seeds to locations determined by IPSA and the ability of the system to incorporate novel needle patterns were demonstrated. Shown here is the ability to overcome this critical step. An adaptive brachytherapy workflow is demonstrated which integrates a clinical anatomy-based seed location optimization engine and a robotic brachytherapy device. Demonstration of this workflow is a key element of a successful translation to the clinic of the MRI stealth robotic delivery system, MRBot.     

A magnetic resonance image-guided breast needle intervention robot system: overview and design considerations

Purpose

We developed an image-guided intervention robot system that can be operated in a magnetic resonance (MR) imaging gantry. The system incorporates a bendable needle intervention robot for breast cancer patients that overcomes the space limitations of the MR gantry.

Methods

Most breast coil designs for breast MR imaging have side openings to allow manual localization. However, for many intervention procedures, the patient must be removed from the gantry. A robotic manipulation system with integrated image guidance software was developed. Our robotic manipulator was designed to be slim, so as to fit between the patient’s side and the MR gantry wall. Only non-magnetic materials were used, and an electromagnetic shield was employed for cables and circuits. The image guidance software was built using open source libraries. In situ feasibility tests were performed in a 3-T MR system. One target point in the breast phantom was chosen by the clinician for each experiment, and our robot moved the needle close to the target point.

Results

Without image-guided feedback control, the needle end could not hit the target point (distance = 5 mm) in the first experiment. Using our robotic system, the needle hits the target lesion of the breast phantom at a distance of 2.3 mm from the same target point using image-guided feedback. The second experiment was performed using other target points, and the distance between the final needle end point and the target point was 0.8 mm.

Conclusions

We successfully developed an MR-guided needle intervention robot for breast cancer patients. Further research will allow the expansion of these interventions.

     

MR-guided interventions for prostate cancer

MR imaging is currently the most effective diagnostic imaging tool for visualizing the anatomy and pathology of the prostate gland. Currently, the practicality and cost effectiveness of transrectal ultrasound dominates image guidance for needle-based prostate interventions. Challenges to the integration of diagnostic and interventional MR imaging have included the lack of real-time feed-back, the complexity of the imaging technique, and limited access to the perineum within the geometric constraints of the MR imaging scanner. Two basic strategies have been explored and clinically demonstrated in the literature: (1) coregistration of previously acquired diagnostic MR imaging to interventional TRUS or open scanner MR images, and (2) stereotactic needle interventions within conventional diagnostic scanners using careful patient positioning or the aid of simple manipulators. Currently, researchers are developing techniques that render MR imaging the method of choice for the direct guidance of many procedures. This article focuses on needle-based interventions for prostate cancer, including biopsy, brachytherapy, and thermal therapy With rapid progress in biologic imaging of the prostate gland, the authors believe that MR imaging guidance will play an increasing role in the diagnosis and treatment of prostate cancer.     

"MRI Stealth" robot for prostate interventions.

The paper reports an important achievement in MRI instrumentation, a pneumatic, fully actuated robot located within the scanner alongside the patient and operating under remote control based on the images. Previous MRI robots commonly used piezoelectric actuation limiting their compatibility. Pneumatics is an ideal choice for MRI compatibility because it is decoupled from electromagnetism, but pneumatic actuators were hardly controllable. This achievement was possible due to a recent technology breakthrough, the invention of a new type of pneumatic motor, PneuStep 1, designed for the robot reported here with uncompromised MRI compatibility, high-precision, and medical safety. MrBot is one of the "MRI stealth" robots today (the second is described in this issue by Zangos et al.). Both of these systems are also multi-imager compatible, being able to operate with the imager of choice or cross-imaging modalities. For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, crystals, rubbers and is electricity free. Light-based encoding is used for feedback, so that all electric components are distally located outside the imager's room. MRI robots are modern, digital medical instruments in line with advanced imaging equipment and methods. These allow for accessing patients within closed bore scanners and performing interventions under direct (in scanner) imaging feedback. MRI robots could allow e.g. to biopsy small lesions imaged with cutting edge cancer imaging methods, or precisely deploy localized therapy at cancer foci. Our robot is the first to show the feasibility of fully automated in-scanner interventions. It is customized for the prostate and operates transperineally for needle interventions. It can accommodate various needle drivers for different percutaneous procedures such as biopsy, thermal ablations, or brachytherapy. The first needle driver is customized for fully automated low-dose radiation seed brachytherapy. This paper gives an introduction to the challenges of MRI robot compatibility and presents the solutions adopted in making the MrBot. Its multi-imager compatibility and other preclinical tests are included. The robot shows the technical feasibility of MRI-guided prostate interventions, yet its clinical utility is still to be determined.     

A new robotic assistance system for percutaneous CT-guided punctures: Initial experience

Purpose: To evaluate the feasibility of CT-guided bone biopsies using a novel robotic needle guide. Material and methods: The robotic needle guide iSYS 1.3 (iSYS Medzintechnik, GmbH, Kitzbuehel, Austria) mounted on the standard table of a CT scanner was used for all studies. For preclinical testing, eight vertebral bodies of dead swine were biopsied, trying to place the needle in the center of the vertebral body via a transpedicular access. For clinical evaluation, bone biopsies were taken in three different patients with ambiguous bone lesions. All biopsies were performed under general anesthesia, using a 12G bone biopsy needle. Results: The animal studies demonstrated that the biopsy needle could be placed accurately in the center of the vertebral body in all cases. No readjustment was necessary, the CT scans demonstrated an intrapedicular trajectory avoiding the spinal canal or the neural foramina. Subsequently, following the animal studies, all biopsies could be performed successfully. Needle placement was accurate without any need for readjustment. No complications occurred during the procedure. Conclusion: Using the iSYS 1.3 allows for accurate and simple stereotactic biopsies of bone lesions, avoiding the need for needle readjustment. The systems may offer even less experienced teams to take biopsies in regions which are difficult to access.     

Robotic assistance for ultrasound-guided prostate brachytherapy

We present a robotically assisted prostate brachytherapy system and test results in training phantoms and Phase-I clinical trials. The system consists of a transrectal ultrasound (TRUS) and a spatially co-registered robot, fully integrated with an FDA-approved commercial treatment planning system. The salient feature of the system is a small parallel robot affixed to the mounting posts of the template. The robot replaces the template interchangeably, using the same coordinate system. Established clinical hardware, workflow and calibration remain intact. In all phantom experiments, we recorded the first insertion attempt without adjustment. All clinically relevant locations in the prostate were reached. Non-parallel needle trajectories were achieved. The pre-insertion transverse and rotational errors (measured with a Polaris optical tracker relative to the template's coordinate frame) were 0.25 mm (STD=0.17 mm) and 0.75 degrees (STD=0.37 degrees). In phantoms, needle tip placement errors measured in TRUS were 1.04 mm (STD=0.50mm). A Phase-I clinical feasibility and safety trial has been successfully completed with the system. We encountered needle tip positioning errors of a magnitude greater than 4mm in only 2 of 179 robotically guided needles, in contrast to manual template guidance where errors of this magnitude are much more common. Further clinical trials are necessary to determine whether the apparent benefits of the robotic assistant will lead to improvements in clinical efficacy and outcomes.     

Photoacoustic-guided surgery from head to toe [Invited]

Photoacoustic imaging–the combination of optics and acoustics to visualize differences in optical absorption – has recently demonstrated strong viability as a promising method to provide critical guidance of multiple surgeries and procedures. Benefits include its potential to assist with tumor resection, identify hemorrhaged and ablated tissue, visualize metal implants (e.g., needle tips, tool tips, brachytherapy seeds), track catheter tips, and avoid accidental injury to critical subsurface anatomy (e.g., major vessels and nerves hidden by tissue during surgery). These benefits are significant because they reduce surgical error, associated surgery-related complications (e.g., cancer recurrence, paralysis, excessive bleeding), and accidental patient death in the operating room. This invited review covers multiple aspects of the use of photoacoustic imaging to guide both surgical and related non-surgical interventions. Applicable organ systems span structures within the head to contents of the toes, with an eye toward surgical and interventional translation for the benefit of patients and for use in operating rooms and interventional suites worldwide. We additionally include a critical discussion of complete systems and tools needed to maximize the success of surgical and interventional applications of photoacoustic-based technology, spanning light delivery, acoustic detection, and robotic methods. Multiple enabling hardware and software integration components are also discussed, concluding with a summary and future outlook based on the current state of technological developments, recent achievements, and possible new directions.     

Robotics in the clinical laboratory

We are beginning to see the potential of robotics in the clinical laboratory through integration with automated analyzers and computer systems. However, there is a need for training programs that will prepare technologists to design and implement robotic systems for clinical laboratories. What will the robot laboratory of the future look like? We will see hospital laboratories begin to be located some distance away from the main facility because the labor component of staffing satellite laboratories will have been greatly reduced. Instrument manufacturers will see the need for analyzers that are robot-friendly and allow for simplified interfacing, both electronic and mechanical. Robots will become more versatile even to the point of performing complete instrument repair. Laboratories will be equipped with many task-oriented robotic stations, including, for example, accessioning and processing robots that prepare samples for transport by robotic carts. Analysis will be performed by a combination of robot and dedicated analyzer. Laboratory results will be reviewed by algorithms in the larger laboratory computer, which will alert the laboratory worker to unusual results. A large variety of analyses will be available to the patient with rapid turnaround. The end result will be more efficient health care delivery at reduced cost.     

The challenging image-guided abdominal mass biopsy: established and emerging techniques ‘if you can see it, you can biopsy it’

Image-guided percutaneous biopsy of abdominal masses is among the most commonly performed procedures in interventional radiology. While most abdominal masses are readily amenable to percutaneous biopsy, some may be technically challenging for a number of reasons. Low lesion conspicuity, small size, overlying or intervening structures, motion, such as that due to respiration, are some of the factors that can influence the ability and ultimately the success of an abdominal biopsy. Various techniques or technologies, such as choice of imaging modality, use of intravenous contrast and anatomic landmarks, patient positioning, organ displacement or trans-organ approach, angling CT gantry, triangulation method, real-time guidance with CT fluoroscopy or ultrasound, sedation or breath-hold, pre-procedural image fusion, electromagnetic tracking, and others, when used singularly or in combination, can overcome these challenges to facilitate needle placement in abdominal masses that otherwise would be considered not amenable to percutaneous biopsy. Familiarity and awareness of these techniques allows the interventional radiologist to expand the use of percutaneous biopsy in clinical practice, and help choose the most appropriate technique for a particular patient.     

Navigated CT-guided interventions.

Diagnostic and therapeutic CT- guided percutaneous interventions are clinical routine in interventional radiology. Image-guided navigation systems visualize the internal anatomy during interventions in real time not necessitating continuous image acquisition. Although multiple 3D image-guidance devices have been developed and used by several surgical disciplines in the last few years, they have not yet been fully applied by the interventional radiologist. The aim of this article is to review the currently performed methods of CT-guided percutaneous interventions and to discuss the potential benefits of newly developed 3D- navigation systems.     

Role of CT Imaging for Coronary and Non-coronary Interventions

Purpose of Review

Pre-procedural imaging is essential for successful planning and performance of several cardiac interventions. Cardiac computed tomography (CT) is a non-invasive imaging modality capable of providing precise information required for different coronary and non-coronary interventions. The role of cardiac CT for the guidance of different cardiac interventions will be described in this review.

Recent Findings

Contrast-enhanced computed tomography imaging is increasingly being used for guiding transcatheter cardiac interventions. Anatomical and functional information provided by CT helps in successful planning and performance of several cardiac interventions.

Summary

Over the last decade, the continuous growth of interventional cardiology has been associated with widespread acknowledgment that CT is particularly useful for pre-interventional imaging with increasing implementation in clinical routine.

     

Image-guided robotic delivery system for precise placement of therapeutic agents.

The effectiveness of conventional solid tumor treatment is limited by the systemic toxicity and lack of specificity of chemotherapeutic agents. Present treatment modalities are frequently insufficient to eliminate competent cancer cells without exceeding the limits of toxicity to normal tissue. The coming generation of cancer therapeutics depends on the precise targeting and sustained release of antitumor agents to overcome these limitations. We are developing an image-guided, robotic system for precise intratumoral placement of anticancer drugs and sustained release devices to advance this new treatment paradigm. The robotic system will use intraoperatively obtained computed tomographic (CT) images from a mobile CT scanner for guidance. The concept is to track patient anatomy and localize instruments using currently available optical tracking technology. Tracking will also be used to register patient anatomy with the images. The physician can then use the registered image to select an appropriate tumor target and entry location and to plan the instrument path. This path will then be transmitted to the robot, which orients and drives the instrument to the desired target under physician control. Achievement of the target is confirmed via intraoperative CT. This system will provide instrument guidance that is precise, direct, and controllable. Error due to poor target visualization and hand unsteadiness should be reduced greatly. The basic components of the system (robot, mobile CT, tracking) have been demonstrated in our laboratory, and the integration of the components is in progress. In future work, we plan to fuse preoperative PET imaging with intraoperative CT to allow functional as well as anatomic image guidance.     

Image fusion and navigation platforms for percutaneous image-guided interventions

Image-guided interventional procedures, particularly image guided biopsy and ablation, serve an important role in the care of the oncology patient. The need for tumor genomic and proteomic profiling, early tumor response assessment and confirmation of early recurrence are common scenarios that may necessitate successful biopsies of targets, including those that are small, anatomically unfavorable or inconspicuous. As image-guided ablation is increasingly incorporated into interventional oncology practice, similar obstacles are posed for the ablation of technically challenging tumor targets. Navigation tools, including image fusion and device tracking, can enable abdominal interventionalists to more accurately target challenging biopsy and ablation targets. Image fusion technologies enable multimodality fusion and real-time co-displays of US, CT, MRI, and PET/CT data, with navigational technologies including electromagnetic tracking, robotic, cone beam CT, optical, and laser guidance of interventional devices. Image fusion and navigational platform technology is reviewed in this article, including the results of studies implementing their use for interventional procedures. Pre-clinical and clinical experiences to date suggest these technologies have the potential to reduce procedure risk, time, and radiation dose to both the patient and the operator, with a valuable role to play for complex image-guided interventions.     

Fundamentals and Potential of Magnetic Particle Imaging

Cardiovascular interventions are standard treatment for numerous cardiovascular conditions and require high fidelity imaging tools to accurately visualize both vessels and interventional devices. Currently, digital subtraction angiography (DSA) is the standard method for peripheral arterial angiography. Magnetic particle imaging (MPI) is a new imaging modality, free of ionizing radiation, that utilizes static and oscillating magnetic fields to provide high temporal resolution, sub-millimeter spatial resolution images and high sensitivity. Superparamagnetic iron oxide nanoparticles (SPIOs) are used as tracers in MPI and signals are based on non-linear magnetization characteristics of those SPIOs. Regarding the magnetic moment of used tracers in MPI imaging is much faster in MPI, compared to imaging in CT and MRI. This makes MPI also very attractive for cardiovascular imaging and cardiovascular interventions. First in vivo visualization of a beating mouse heart demonstrated the feasibility of the visualization of the cardiovascular system by MPI. Different scanner designs and acquisition methods have already emerged addressing the requirements of cardiovascular interventions. Early studies have demonstrated MPI as an interesting and promising cardiovascular imaging modality. Technical improvement in hardware MPI imaging systems are currently being addressed in ongoing research which will facilitate former image acquisition with higher resolution in larger animals and/or human.     

Interventions to promote upper limb recovery in stroke survivors with severe paresis: a systematic review

Purpose.?To investigate the effect of interventions that promote upper limb (UL) recovery in stroke survivors with severe paresis.

Methods.?A systematic search of the scientific literature from January 1970 to March 2009 was conducted using CINAHL, Cochrane, PEDro, Pubmed and Web of Science. keywords used included stroke, severe, hemiplegia, UL, task-oriented, robot, non-robot and electrical stimulation. Methodological quality of the studies was assessed using the PEDro rating scale. Studies were grouped into one of three intervention categories: robotic therapy, electrical stimulation or ‘other’ therapy.

Results.?Seventeen randomised controlled trials met the inclusion criteria. A ‘best evidence synthesis’ indicated strong evidence that robotic therapy provides a large beneficial effect and limited evidence that electrical stimulation and ‘other’ interventions provide a large beneficial effect on function. There is no evidence that these interventions influence use of the arm in everyday tasks.

Conclusion.?There are a number of newly developed interventions that enable stroke survivors with severe paresis to actively participate in task-oriented practice to promote UL recovery. While these interventions offer some promise for stroke survivors with severe paresis, ultimately, the effectiveness of these interventions will be dependent on whether they lead to restoration of function to the point at which the stroke survivor can practice everyday tasks.