Paul Thienphrapa

Johns Hopkins University | JHU

Historically, the architecture of robot controllers has been dictated by technology constraints. When computers and networks were slow, it was necessary to logically distribute the computation but to physically centralize both the computation and I/O. This is represented by a controller comprised of large rack of embedded processors, with cables to...

The James Webb Space Telescope (JWST) is expected to produce a vast amount of images that are valuable for astronomical research and education. To support research activities related to the mission, the National Aeronautical and Space Administration (NASA) has provided funds to establish the Structures Pointing and Control Engineering (SPACE) Labor...

Alongside sweeping transformations in healthcare, a timeless drive to make surgical interventions less invasive and more effective has led to the integration of disparate technologies into surgical navigation systems. Fusions of device tracking and medical imaging modalities have been comprehensively investigated for opportunities to improve care....

Computer generated graphics are superimposed onto live video emanating from an endoscope, offering the surgeon visual information that is hiding in the native scene--this describes the classical scenario of augmented reality in minimally invasive surgery. Research efforts have, over the past few decades, pressed considerably against the challenges...

Intuitive design may become an integral component of medical technology, much like it has in the consumer space, as a number of undercurrents converge. These include increasing burdens on clinical practitioners, growing demands on health systems, and the advancing complexities of technology. Surgical systems serve highly trained experts performing...

Emerging technologies for the operating room are subject to evaluation against the Quadruple Aim, which describes healthcare performance as a union of: patient satisfaction, clinical outcomes, provider satisfaction, and operational efficiency. Consequently, new developments will be expected to fulfill multiple aims simultaneously. This paper outlin...

Minimally invasive surgery is the preferred treatment option for patients with early stage lung cancer. As lung cancer screening programs are adopted, localizing small, non-palpable nodules during surgery will become more challenging. CT/CBCT guided placement of markers has evolved to aid in nodule localization [1]. However, there are several disad...

A minimally invasive surgical technique, video assisted thoracoscopic surgery or VATS, has emerged over the last 15-20 years as the de facto standard of care for lung tumor resection, comprising ~60% of surgical cases in the US [1]. Surgeons insert tools through small ports between the ribs, one tool being a thoracoscope used to view the inside of...

Particles such as thrombi, bullet fragments, and shrapnel can become trapped in a person's heart after migrating through the venous system, or by direct penetration. These cardiac foreign bodies pose a serious health risk as they can interfere with cardiovascular function. Conventional treatment often requires open heart surgery, cardiopulmonary by...

In this paper, we demonstrate the use of a high dexterity, minimally invasive surgical robot to retrieve a foreign body from a beating heart phantom. Streaming 3D TEE imaging is used to track the foreign body, compute a suitable capture location, and guide the robot to secure it. This effort differs from related works that focus on rigid tools or o...

We propose a minimally invasive surgical approach using an image-guided robotic end effector, to avoid the disadvantages of sternotomy and CPB. In the envisioned scenario, a robotic tool is inserted transapically into the heart after detection of the foreign body using preoperative imaging. Under intraoperative ultrasound guidance, the robot moves...

By way of the venous system or direct penetration, particles such as thrombi, bullet fragments, and shrapnel can become trapped in the heart and disrupt cardiac function. The severity of disruption can range from asymptomatic to fatal. Injuries of this nature are common in both civilian and military populations. For symptomatic cases, the conventio...

Free moving bodies in the heart pose a serious health risk as they may be released in the arteries causing blood flow disruption. These bodies may be the result of various medical conditions and trauma. The conventional approach to removing these objects involves open surgery with sternotomy, the use of cardiopulmonary bypass, and a wide resection...

Cardiovascular disease is a leading cause of death in the United States with over 1 million people experiencing sudden cardiac death or myocardial infarction every year. There has been a growing interest in minimally invasive cardiac interventions and the global market for image guided navigation is estimated by some to grow to the tune of $600 mil...

Research in surgical robots often calls for multi-axis controllers and other I/O hardware for interfacing various devices with computers. As the need for dexterity is increased, the hardware and software interfaces required to support additional joints can become cumbersome and impractical. To facilitate prototyping of robots and experimentation wi...

Fragments generated by explosions and similar incidents can become trapped in a patient's heart chambers, potentially causing disruption of cardiac function. The conventional approach to removing such foreign bodies is through open heart surgery, which comes with high perioperative risk and long recovery times. We thus advocate a minimally invasive...

Minimally invasive cardiac surgery is performed under direct vision provided by an endoscope. During cardiac bypass surgery, counterintuitive control and small field-of-view endoscopic visualization is not sufficient to localize all relevant structures of the heart. This work presents a first step towards enhanced endoscopic visualization in cardi...

Research in surgical robots often calls for multi-axis motor controllers and other I/O hardware for interfacing various devices with computers. To facilitate convenient prototyping of robots with large numbers of axes and I/O lines, it would be beneficial to have controllers that scale well in this regard. We would like to incorporate additional co...

The requisite cabling and control processing for surgical robots can become unwieldy as dexterity is increased, due to the additional degrees of freedom. Motivated by dexterous snake-like robots for minimally invasive surgery, this paper details the development of a low-level control system that uses IEEE 1394 (FireWire), linking the computer to lo...

A robot can be seen as a set of actuated joints, each connected to a processing unit that senses feedback signals and generates actuation commands. For robots with high locomotive sophistication, commonly seen in medical robotics, the requisite cabling and control processing can become unwieldy. Motivated by dexterous snake-like robots for minimall...

A proposed transmission system adopts content-based error correction to maximize the quality of astronomical images transmitted over the Internet to educators and researchers.

The James Webb Space Telescope (JWST) is expected to produce a vast amount of images that are valuable for astronomical research and education. To support research activities related to JWST mission, NASA has provided funds to establish the Structures Pointing and Control Engineering (SPACE) Laboratory at the California State University, Los Angele...

Complex control-oriented structures are inherently multiple input, multiple output systems whose complexities increase significantly with each additional parameter. When precision performance in both space and time is required, these types of applications can be described as real-time systems that demand substantial amounts of computational power i...

Control of complex, flexible structures requires substantial amounts of computational power to achieve precision performance in both space and time. This is due to the fact that such structures are inherently multiple input, multiple output systems whose complexities increase significantly with each additional input or output parameter. The other d...

This paper presents a technology of generic group-pipelined scheduling for decentralized control of large flexible structures of a segmented reflector telescope, the James Webb Space Telescope (JWST) testbed. Such a structure is controlled by a number of lower-order decentralized local controllers, leading to reduced computational complexities, and...

Control of complex structures requires high computational power to achieve real-time performance. Through decentralized techniques, a complex structure can be controlled by multiple lower-order local controllers, leading to reduced computational complexities. Furthermore, a decentralized approach can both simplify the development of parallel contro...

The control of complex, flexible structures requires substantial amounts of computational power to achieve precision performance in both space and time. This is due to the fact that such structures are inherently multiple input, multiple output systems whose complexities increase significantly with each additional parameter. The application of dece...