Nevan C. Hanumara

A Patient-Mounted, Telerobotic Tool for CT-Guided Percutaneous Interventions

This paper describes Robopsy, an economical, patient-mounted, telerobotic, needle guidance and insertion system, that enables faster, more accurate targeting during CT-guided biopsies and other percutaneous interventions. The current state of the art imaging technology facilitates precise location of sites within the body; however, there is no mechanical equivalent to then facilitate precise targeting. The lightweight, disposable actuator unit, which affixes directly to the patient, is composed primarily of inexpensive, injection molded, radiolucent, plastic parts that snap together, whereas the four micromotors and control electronics are retained and reused. By attaching to a patient, via an adhesive pad and optional strap points, the device moves passively with patient motion and is thus inherently safe. The device’s mechanism tilts the needle to a two degree-of-freedom compound angle, toward the patient’s head or feet (in and out of the scanner bore) and left or right with respect to the CT slice, via two motor-actuated concentric, crossed, and partially nested hoops. A carriage rides in the hoops and interfaces with the needle via a two degree-of-freedom friction drive that both grips the needle and inserts it. This is accomplished by two rubber rollers, one passive and one driven, that grip the needle via a rack and pinion drive. Gripping is doctor controlled; thus when not actively being manipulated, the needle is released and allowed to oscillate within a defined region so as to minimize tissue laceration due to the patient breathing. Compared to many other small robots intended for medical applications, Robopsy is an order of magnitude less costly and lighter while offering appropriate functionality to improve patient care and procedural efficiency. This demonstrates the feasibility of developing cost-effective disposable medical robots, which could enable their more widespread application.

An overview of systems for CT‐ and MRI‐guided percutaneous needle placement in the thorax and abdomen

Minimally invasive biopsies, drainages and therapies in the soft tissue organs of the thorax and abdomen are typically performed through a needle, which is inserted percutaneously to reach the target area. The conventional workflow for needle placement employs an iterative freehand technique. This article provides an overview of needle‐placement systems developed to improve this method.

Development and evaluation of a new image-based user interface for robot-assisted needle placements with the Robopsy system

The main challenges of Computed Tomography (CT)-guided organ puncture are the mental registration of the medical imaging data with the patient anatomy, required when planning a trajectory, and the subsequent precise insertion of a needle along it. An interventional telerobotic system, such as Robopsy, enables precise needle insertion, however, in order to minimize procedure time and number of CT scans, this system should be driven by an interface that is directly integrated with the medical imaging data. In this study we have developed and evaluated such an interface that provides the user with a point-and-click functionality for specifying the desired trajectory, segmenting the needle and automatically calculating the insertion parameters (angles and depth). In order to highlight the advantages of such an interface, we compared robotic-assisted targeting using the old interface (non-image-based) where the path planning was performed on the CT console and transferred manually to the interface with the targeting procedure using the new interface (image-based). We found that the mean procedure time (n=5) was 22±5 min (non-image-based) and 19±1 min (image-based) with a mean number of CT scans of 6±1 (non-image-based) and 5±1 (image-based). Although the targeting experiments were performed in gelatin with homogenous properties our results indicate that an image-based interface can reduce procedure time as well as number of CT scans for percutaneous needle biopsies.

A Remote Needle Guidance System for Percutaneous Biopsies

This paper describes a teleoperated needle guidance and insertion tool to assist doctors in performing minimally invasive percutaneous biopsies remotely under computed tomography [CT] guidance. Robopsy is a user-friendly robotic device that grips, positions and inserts a biopsy needle while the patient is imaged to provide the radiologist with simultaneous needle position feedback. Patient care is improved through more precise targeting and shortened procedure times. Robopsy is made primarily of simple, lightweight, snap-together, disposable plastic parts and modular motors; contrasting devices are heavy, complex and expensive. It is designed to be taped onto a patient so as to passively compensate for respiratory chest motion and, additionally, it incorporates a novel feature, which compensates for passive needle oscillation. The design process is outlined and the first prototype presented. Initial results from testing on a cardiac phantom indicate that artifacts from the device in the CT images are negligible and that the device can successfully orientate and insert a needle remotely.

Smaller and deeper lesions increase the number of acquired scan series in computed tomography-guided lung biopsy.

Purpose To determine factors influencing the number of acquired scan series and subsequently the radiation dose and time during computed tomography (CT)-guided lung biopsies. Materials and Methods This Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, retrospective study reviewed 50 consecutive procedures. Each procedure was separated into the following steps: trajectory planning, needle placement, needle insertion (extrapulmonary and intrapulmonary), and sampling and follow-up. The number of scan series, time, and radiation dose were calculated for each procedure and its steps. The effects of patient characteristics (age, sex, history of surgery that violated the pleura), procedure characteristics (needle-pleural angle, patient position), and lesion characteristics (size, depth, lobar location) on the number of scan series for the procedure and each step were evaluated using stepwise linear regression. The overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were also calculated. Results The mean number of total CT scans was 21, the mean effective dose was 14 mSv, and the mean entrance skin dose was 249 mGy. On average, trajectory planning and needle insertion contributed most to the number of scan series (18.5% and 52.9%, respectively). For trajectory planning, a smaller lesion size and shallower needle-pleural angle were associated with an increased number of scans (R2=0.200, P=0.005). During needle insertion, smaller lesions were associated with increased scanning (R2=0.296, P<0.001), with both smaller and deeper lesions associated with an increased number of scans during the intrapulmonary component (R2=0.372, P<0.001). For the entire procedure, smaller lesions were associated with an increased number of scans (R2=0.12, P=0.01). Conclusion Lesions that are smaller or deeper in the lung result in a higher number of CT scans, resulting in increased radiation dose and procedure time, with most of these performed during the needle insertion step.

Classroom to Clinic: Merging Education and Research to Efficiently Prototype Medical Devices

Innovation in patient care requires both clinical and technical skills, and this paper presents the methods and outcomes of a nine-year, clinical-academic collaboration to develop and evaluate new medical device technologies, while teaching mechanical engineering. Together, over the course of a single semester, seniors, graduate students, and clinicians conceive, design, build, and test proof-of-concept prototypes. Projects initiated in the course have generated intellectual property and peer-reviewed publications, stimulated further research, furthered student and clinician careers, and resulted in technology licenses and start-up ventures.

Human Factors Design for Intuitive Operation of a Low-cost, Image-Guided, Tele-Robotic Biopsy Assistant

This paper details the design and interface development of RobopsyTM, an economical, tele-operated, patient mounted, disposable needle guidance and insertion system to assist radiologists in performing minimally invasive percutaneous biopsies remotely under CT guidance. Testing with a phantom in a realistic surgical setting was conducted to ensure that the interface was intuitive and facilitated smooth integration of the device into current procedure. Ease of learning and operation is critical in order to encourage rapid adoption of this new medical robotics model.

Wearable optical-digital assistive device for low vision students

People with low vision have limited residual vision that can be greatly enhanced through high levels of magnification. Current assistive technologies are tailored for far field or near field magnification but not both. In collaboration with L.V. Prasad Eye Institute (LVPEI), a wearable, optical-digital assistive device was developed to meet the near and far field magnification needs of students. The critical requirements, system architecture and design decisions for each module were analyzed and quantified. A proof-of-concept prototype was fabricated that can achieve magnification up to 8x and a battery life of up to 8 hours. Potential user evaluation with a Snellen chart showed identification of characters not previously discernible. Further feedback suggested that the system could be used as a general accessibility aid.

Low vision system for rapid near- and far-field magnification switching

People suffering from low vision, a condition caused by a variety of eye-related diseases and/or disorders, find their ability to read greatly improved when text is magnified between 2 and 6 times. Assistive devices currently on the market are either geared towards reading text far away (~20 ft.) or very near (~2 ft.). This is a problem especially for students suffering from low vision, as they struggle to flip their focus between the chalkboard (far-field) and their notes (near- field). A solution to this problem is of high interest to eye care facilities in the developing world - no devices currently exist that have the aforementioned capabilities at an accessible price point. Through consultation with specialists at L.V. Prasad Eye Institute in India, the authors propose, design and demonstrate a device that fills this need, directed primarily at the Indian market. The device utilizes available hardware technologies to electronically capture video ahead of the user and zoom and display the image in real-time on LCD screens mounted in front of the users eyes. This design is integrated as a wearable system in a glasses form-factor.

Teaching Creativity in Design Through Project-Based Learning in a Collaborative Distributed Educational Setting

This chapter presents the challenge of teaching creativity in design through project-based learning (PBL) in a collaborated distributed educational setting. First, PBL engineering class examples regarding computer-aided design for a toy modeling and original design/modeling for a remote controlled robot are presented, as a starting point of this challenge, from two different institutions, or the University of Tokushima in Japan and Massachusetts Institute of Technology in the USA. After reviewing these classes, several critical elements are identified for the success of these classes. Considering these elements, PBL provides not only an effective approach for teaching creativity in education in a university setting, but also could be applied more generally in a global setting. The second part of this chapter presents the challenge of teaching creativity in a global project using the web-based design and manufacturing of a dental milling machine, followed by a dental headrest project by the process of expectation management. Reviewing the critical roles of conventional learning management systems in these PBL classes and the current trends of cloud computing, this chapter shows the potential of cloud-based design and manufacturing to support creativity in design education.