Mark Yim - Academia.edu (original) (raw)

Papers by Mark Yim

Steerable needles are a novel technology that offers a wide range of uses in medical diagnostics ... more Steerable needles are a novel technology that offers a wide range of uses in medical diagnostics and therapeutics. Currently, there exist several steerable needle designs in the literature, however, they are limited in their use by the number of possible turns, turn radius, and tissue damage. We introduce a novel design of a tape spring steerable needle, capable of multiple turns, that minimizes tissue damage. In this study, we measure the turning radius of our steerable needle in porcine liver tissue in vitro with ultrasound and estimate tissue damage in gel blocks using image analysis and 3D plaster casting. We were able to demonstrate our steerable needle's ability to steer through biological tissue, as well as introduce a novel method for estimating tissue damage. Our findings show that our needle design showed lower damage compared to similar designs in literature, as well as tissue stiffness being a protective factor against tissue damage.

We present a novel design for a low-cost robotic boat powered by a single actuator, useful for bo... more We present a novel design for a low-cost robotic boat powered by a single actuator, useful for both modular and swarming applications. The boat uses the conservation of angular momentum and passive flippers to convert the motion of a single motor into an adjustable paddling motion for propulsion and steering. We develop design criteria for modularity and swarming and present a prototype implementing these criteria. We identify significant mechanical sensitivities with the presented design, theorize about the cause of the sensitivities, and present an improved design for future work.

bioRxiv (Cold Spring Harbor Laboratory), May 7, 2023

Objective: To make steerable needles more effective, researchers have been trying to minimize tur... more Objective: To make steerable needles more effective, researchers have been trying to minimize turning radius, develop mechanics-based models, and simplify control. This paper introduces a novel cable-driven steerable needle that has a 3mm turning radius based on tape spring mechanics, which sets a new minimum turn radius in stiffness-matched tissue models. Methods: We characterize the turn radius and the forces that affect control and performance and create predictive models to estimate required insertion forces and maximum insertion depth. Finally, we demonstrate the performance of a task outside the capabilities of a conventional needle. Results: Minimal force is required to maintain bends, allowing surrounding tissue to fix them in place, and minimal energy is required to propagate bends, allowing the device to navigate easily through various tissue phantoms. The turn radius of the device is independent of surrounding tissue stiffness, making for simple and precise control. We show that all aspects of performance depend on minimizing the tip cutting force. Under ultrasound guidance, we successfully navigate into and then follow a deep blood vessel model at a steep angle of approach. Conclusion: This design allows the system to accurately control the direction of the device while maintaining a smaller turn radius than other steerable needles, providing the potential to broaden access to challenging targets in patients.

arXiv (Cornell University), Apr 18, 2022

The most common sensing modalities found in a robot perception system are vision and touch, which... more The most common sensing modalities found in a robot perception system are vision and touch, which together can provide global and highly localized data for manipulation. However, these sensing modalities often fail to adequately capture the behavior of target objects during the critical moments as they transition out of static, controlled contact with an end-effector to dynamic and uncontrolled motion. In this work, we present a novel multimodal visuotactile sensor that provides simultaneous visuotactile and proximity depth data. The sensor integrates an RGB camera and air pressure sensor to sense touch with an infrared time-of-flight (ToF) camera to sense proximity by leveraging a selectively transmissive soft membrane to enable the dual sensing modalities. We present the mechanical design, fabrication techniques, algorithm implementations, and evaluation of the sensor's tactile and proximity modalities. The sensor is demonstrated in three open-loop robotic tasks: approaching and contacting an object, catching, and throwing. The fusion of tactile and proximity data could be used to capture key information about a target object's transition behavior for sensor-based control in dynamic manipulation.

arXiv (Cornell University), Sep 1, 2021

arXiv (Cornell University), Sep 8, 2022

The Modboat is a low-cost, underactuated, modular robot capable of surface swimming, docking to o... more The Modboat is a low-cost, underactuated, modular robot capable of surface swimming, docking to other modules, and undocking from them using only a single motor and two passive flippers. Undocking is achieved by causing intentional self-collision between the tails of neighboring modules in certain configurations; this becomes a challenge, however, when collective swimming as one connected component is desirable. In this work, we develop a centralized control strategy to allow arbitrary configurations of Modboats to swim as a single steerable vehicle and guarantee no accidental undocking. We also present a simplified model for hydrodynamic interactions between boats in a configuration that is tractable for real-time control. We experimentally demonstrate that our controller performs well, is consistent for configurations of various sizes and shapes, and can control both surge velocity and yaw angle simultaneously. Controllability is maintained while swimming, but pure yaw control causes lateral movement that cannot be counteracted by the presented framework.

arXiv (Cornell University), Dec 10, 2018

Building structures can allow a robot to surmount large obstacles, expanding the set of areas it ... more Building structures can allow a robot to surmount large obstacles, expanding the set of areas it can reach. This paper presents a planning algorithm to automatically determine what structures a construction-capable robot must build in order to traverse its entire environment. Given an environment, a set of building blocks, and a robot capable of building structures, we seek a optimal set of structures (using a minimum number of building blocks) that could be built to make the entire environment traversable with respect to the robot's movement capabilities. We show that this problem is NP-Hard, and present a complete, optimal algorithm that solves it using a branch-and-bound strategy. The algorithm runs in exponential time in the worst case, but solves typical problems with practical speed. In hardware experiments, we show that the algorithm solves 3D maps of real indoor environments in about one minute, and that the structures selected by the algorithm allow a robot to traverse the entire environment. An accompanying video is available online at https://youtu.be/B9WM557NP44.

arXiv (Cornell University), Sep 30, 2021

This paper develops a decentralized approach to mobile sensor coverage by a multi-robot system. W... more This paper develops a decentralized approach to mobile sensor coverage by a multi-robot system. We consider a scenario where a team of robots with limited sensing range must position itself to effectively detect events of interest in a region characterized by areas of varying importance. Towards this end, we develop a decentralized control policy for the robotsrealized via a Graph Neural Network-which uses inter-robot communication to leverage non-local information for control decisions. By explicitly sharing information between multihop neighbors, the decentralized controller achieves a higher quality of coverage when compared to classical approaches that do not communicate and leverage only local information available to each robot. Simulated experiments demonstrate the efficacy of multi-hop communication for multi-robot coverage and evaluate the scalability and transferability of the learningbased controllers.

Science robotics, Oct 17, 2018

The theoretical ability of modular robots to reconfigure in response to complex tasks in a priori... more The theoretical ability of modular robots to reconfigure in response to complex tasks in a priori unknown environments has frequently been cited as an advantage and remains a major motivator for work in the field. We present a modular robot system capable of autonomously completing high-level tasks by reactively reconfiguring to meet the needs of a perceived, a priori unknown environment. The system integrates perception, high-level planning, and modular hardware and is validated in three hardware demonstrations. Given a high-level task specification, a modular robot autonomously explores an unknown environment, decides when and how to reconfigure, and manipulates objects to complete its task. The system architecture balances distributed mechanical elements with centralized perception, planning, and control. By providing an example of how a modular robot system can be designed to leverage reactive reconfigurability in unknown environments, we have begun to lay the groundwork for modular self-reconfigurable robots to address tasks in the real world.

2022 International Conference on Robotics and Automation (ICRA), May 23, 2022

The Modboat is a low-cost, underactuated, modular robot capable of surface swimming. It is able t... more The Modboat is a low-cost, underactuated, modular robot capable of surface swimming. It is able to swim individually, dock to other Modboats, and undock from them using only a single motor and two passive flippers. Undocking without additional actuation is achieved by causing intentional self-collision between the tails of neighboring modules; this becomes a challenge when group swimming as one connected component is desirable. In this work, we develop a control strategy to allow parallel lattices of Modboats to swim as a single unit, which conventionally requires holonomic modules. We show that the control strategy is guaranteed to avoid unintentional undocking and minimizes internal forces within the lattice. Experimental verification shows that the controller performs well and is consistent for lattices of various sizes. Controllability is maintained while swimming, but pure yaw control causes lateral movement that cannot be counteracted by the presented framework.

Innovation in Aging, Dec 1, 2020

Development of low-cost robots to assist older adults requires the input of end users: older adul... more Development of low-cost robots to assist older adults requires the input of end users: older adults, paid caregivers and clinicians. This study builds on prior work focused on the task investigation and deployment of mobile robots in a Program of All-inclusive Care for the Elderly. We identified hydration, walking and reaching as tasks appropriate for the robot and helpful to the older adults. In this study we investigated the design specifications for a socially assistive robot to perform the above tasks. Through focus groups of clinicians, older adults and paid caregivers we sought preferences on the design specifications. Using conventional content analysis, the following four themes emerged: the robot must be polite and personable; science fiction or alien like; depends on the need of the older adult; and multifaceted to meet the needs of older adults. These themes were used in the design and deployment of the Quori robot.

MRS Advances, 2021

We present carbon-fiber and aluminum sandwich plates with millimeter thicknesses that exhibit hig... more We present carbon-fiber and aluminum sandwich plates with millimeter thicknesses that exhibit high stiffness-and strengthto-weight ratios. These composites consist of carbon-fiber-reinforced polymer faces and waterjet-cut aluminum cores, bonded using epoxy. Relative to single-ply carbon-fiber-reinforced polymer sheets, this construction provides 22-fold increases in mass-specific flexural rigidity and 18-fold increases in mass-specific flexural strength, with areal densities of only 120-260 mg/cm 2. Our work represents a simple and inexpensive platform for creating extremely lightweight structural components for microflyers and small robots.

Proceedings 2003 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2003) (Cat. No.03CH37453)

ABSTRACT A common point of weakness in many path/motion planners is dealing with configuration sp... more ABSTRACT A common point of weakness in many path/motion planners is dealing with configuration spaces (C-spaces) that involve narrow gaps of passages. This is caused by the indirect representation of the C-space inherent in those planners. Unfortunately many real environments and tasks give rise to such situations. While a small number of planners do exist which reliably work in these environments, they in turn have problems when the robot has many controllable degrees of freedom. High degree of freedom motion in confined spaces is a typical problem encountered by PARC's PolyBot platform. The algorithm put forward in this paper is designed to work directly with the C-space obstacles' geometry, and so is not hampered by narrow passages. The planner is a homotopic one which solves general problems in n-dimensional C-space. The algorithm's theoretical characteristics are shown to compare very favourably with other contending planners in these specialised domains. Results of some preliminary testing are given.

Springer Tracts in Advanced Robotics, 2006

Page 1. Limbless Conforming Gaits with Modular Robots Mark Yim, Craig Eldershaw, Ying Zhang, Davi... more Page 1. Limbless Conforming Gaits with Modular Robots Mark Yim, Craig Eldershaw, Ying Zhang, David Duff ... In addition several other obstacles were tested. Figure 6 shows a platter that has 4cm high walls that are several millimeter thick. ...

Journal of Intelligent Material Systems and Structures, 1998

This paper describes the design, analysis and characterization of a prototype active column that ... more This paper describes the design, analysis and characterization of a prototype active column that applies distributed MEMS technology to the active stabilization of a buckling compressive member. The axial load bearing capacity of structural members can be increased by actively controlling the dynamic instability of buckling. Effective active stabilization is dependent on three primary factors: sensor precision, actuator authority, and control system bandwidth. A networked array of MEMS sensors, filamentary PZT actuators, and recently developed optimal control strategies are combined to demonstrate active control of an inherently unstable column. The active system, designed and simulated using finite element and optimization methods, stabilizes an experimental column for compressive axial loads up to 2.9 times the critical buckling load. Additionally, the system is stable for all loads in the range from tension to this maximum compressive axial load.

International Statistical Review, 2012

Table of Contents 1. Description of samples and populations 2. Linear regression 3. Comparison of... more Table of Contents 1. Description of samples and populations 2. Linear regression 3. Comparison of groups 4. The normal distribution 5. Statistical models, estimation, and confidence intervals 6. Hypothesis tests 7. Model validation and prediction 8. Linear normal models 9. Probabilities 10. The binomial distribution 11. Analysis of count data 12. Logistic regression 13. Case exercises A. Summary of inference methods B. Introduction to R C. Statistical tables Readership: Students and practitioners of biology and life sciences. This book can be valuable assistance for students of life sciences and the other biological faculties and it can be treated both as a first handbook to statistical methods as well as a suitable tool to systematize earlier experiences. The authors put the emphasis not on mathematical formulas, definitions and theorems but-as they write in the Preface-on "providing the readers a feeling of being able to model and analyze the data". The book is divided into 13 chapters and 3 appendixes. The material introduced in chapters from 1 to 12 is illustrated with many examples and biological problems. Moreover, at the end of each chapter the reader can find a lot of exercises. Some of them are supposed to be done by hand, whereas the remaining should be solved with R-package. The authors prepared one appendix as an introduction to R for readers unfamiliar with this software. The nice advantage of this book is chapter 13 containing 10 case exercises which are more complicated than previous ones and require the compilation of the methods presented before. All the data sets used in the exercises are available from the supporting web site. The book is written in a clear and engaging style. The authors put much emphasis on the modelling part of statistical analysis and on biological interpretation of obtained results. It could be recommended for students but also other readers looking for a handbook of "practical" statistics.

Control Engineering Practice, 1999

Inertially actuated systems are often hindered by the requirement that the actuator or controller... more Inertially actuated systems are often hindered by the requirement that the actuator or controller be explicitly designed so that the actuator's proof mass never exceeds the available stroke length. When the actuator's proof mass reaches the end of its stroke a destabilizing input is created, which reduces performance. An integrated centering controller design that balances control effort with proof mass

IEEE Robotics & Automation Magazine, Mar 1, 2007

he field of modular self-reconfigurable robotic systems addresses the design, fabrication, motion... more he field of modular self-reconfigurable robotic systems addresses the design, fabrication, motion planning, and control of autonomous kinematic machines with variable morphology. Beyond conventional actuation, sensing, and control typically found in fixed-morphology robots, self-reconfigurable robots are also able to deliberately change their own shape by rearranging the connectivity of their parts in order to adapt to new circumstances, perform new tasks, or recover from damage. Over the last two decades, the field of modular robotics has advanced from proof-of-concept systems to elaborate physical implementations and simulations. The goal of this article is to outline some of this progress and identify key challenges and opportunities that lay ahead. A Taxonomy of Architectures Modular robots are usually composed of multiple building blocks of a relatively small repertoire, with uniform docking interfaces that allow transfer of mechanical forces and moments, electrical power, and communication throughout the robot. The modular building blocks often consist of some primary structural actuated unit and potentially some additional specialized units such as grippers, feet, wheels, cameras, payload, and energy storage and generation units. Figure 1 illustrates such a system in the context of a potential application. Modular self-reconfigurable robotic systems can be generally classified into several architectural groups by the geometric arrangement of their units. Several systems exhibit hybrid properties. ◆ Lattice Architectures: Lattice architectures have units that are arranged and connected in some regular, three-dimensional pattern, such as a simple cubic or hexagonal grid. Control and motion can be executed in parallel. Lattice architectures usually offer simpler reconfiguration, as modules move to a discrete set of neighboring locations in which motions can be made open-loop. The computational representation can also be more easily scaled to more complex systems.