Research

Stanford University
    PhD in Computer Science, April 2007
    MS in Computer Science, September 2004
Texas A&M University
    BS in Computer Science, May 2002
    Minors in Electrical Engineering, Mathematics, Chemistry
El Paso Franklin High School
    Diploma, 1998

 

Data-Parallel Algorithms, Visualization, and Analysis for Large-Scale Scientific Simulations

Los Alamos National Laboratory, Los Alamos, New Mexico
Staff Scientist 4, June 2016 - January 2017
Staff Scientist 3, May 2011 - June 2016
My LANL webpage
Data Science at Scale Team
VTK-m webpage

Portable Data-Parallel Surface Reconstruction on a Uniform Rectilinear Grid. Marianne Francois, Li-Ta Lo, Christopher Sewell, and Jan Velechovsky. International Journal for Numerical Methods in Fluids. August 2017. Link

Achieving Portable Performance for Wavelet Compression Using Data Parallel Primitives. Shaomeng Li, Nicole Marsaglia, Vincent Chen, Christopher Sewell, John Clyne, and Hank Childs. Proceedings of the Eurographics Symposium on Parallel Graphics and Visualization (EGPGV). June 2017. Barcelona, Spain.

Parallel Peak Pruning for Scalable SMP Contour Tree Computation. Hamish Carr, Gunther Weber, Christopher Sewell, and James Ahrens. Proceedings of the IEEE Symposium on Large Data Analysis and Visualization (LDAV). October 2016. Baltimore, Maryland. Best Paper Award. Link

Introduction to Portage. Angela Herring, Ondrej Certik, Charles Ferenbaugh, Rao Garmella, Brian Jean, Christopher Malone, and Christopher Sewell. Proceedings of NECDC 2016.

Hybrid Data-Parallel Contour Tree Computation. Hamish Carr, Christopher Sewell, Li-Ta Lo, and James Ahrens. Proceedings of the Computer Graphics and Visual Computing Conference. September 2016. Bournemouth, England.

VTK-m: Accelerating the Visualization Toolkit for Massively Threaded Architectures. Kenneth Moreland, Christopher Sewell, William Usher, Li-ta Lo, Jeremy Meredith, David Pugmire, James Kress, Hendrik Schroots, Kwan-Liu Ma, Hank Childs, Matthew Larsen, Chun-Ming Chen, Robert Maynard, and Berk Geveci. IEEE Computer Graphics and Applications. May/June 2016. Link

Adapting the Visualization Toolkit for Many-Core Processors with the VTK-m Library. Presentation with Robert Maynard at the GPU Technology Conference. April 2016. San Jose, California. Link

Reporting on the Technical Specification for C++ Extensions for Parallelism. Presentation at the Programming Models and Co-Design Meeting. February 2016. Los Alamos, New Mexico.

Large-Scale Compute-Intensive Analysis via a Combined In-situ and Co-scheduling Workflow Approach. Christopher Sewell, Katrin Heitmann, Hal Finkel, George Zagaris, Suzanne T. Parete-Koon, Patricia K. Fasel, Adrian Pope, Nicholas Frontiere, Li-ta Lo, Bronson Messer, Salman Habib, and James Ahrens. Proceedings of The International Conference for High Performance Computing, Networking, Storage, and Analysis. November 2015. Austin, Texas. Link

Utilizing Many-Core Accelerators for Halo and Center Finding within a Cosmology Simulation. Christopher Sewell, Li-ta Lo, Katrin Heitmann, Salman Habib, and James Ahrens. Proceedings of the IEEE Symposium on Large Data Analysis and Visualization (LDAV). October 2015. Chicago, IL. Link

The Q Continuum Simulation: Harnessing the Power of GPU Accelerated Supercomputers. Katrin Heitmann, Nicholas Frontiere, Christopher Sewell, Salman Habib, Adrian Pope, Hal Finkel, Silvio Rizzi, Joe Insley, and Suman Bhattacharya. Astrophysical Journal Supplement Series, 219(34). August 2015. Link

GPU-Accelerated Cosmological Analysis on the Titan Supercomputer. Blog post at Nvidia's Parallel for All Blog. July 2015. Link

Visualization and Analysis of Large-Scale Atomistic Simulations of Plasma-Surface Interactions. Wathsala Widanagamaachchi, Karl Hammond, Li-ta Lo, Brian Wirth, Francesca Samsel, Christopher Sewell, James Ahrens, and Valerio Pascucci. Proceedings of EuroVis (short paper). May 2015. Cagliari, Italy. Link

Portable Data-Parallel Algorithms for Scientific Applications. Presentation at the Department of Energy Computer Graphics Forum. April 2015. Newport, Rhode Island.

Data-Parallel Halo Finding with Variable Linking Lengths. Wathsala Widanagamaachchi, Peer-Timo Bremer, Christopher Sewell, Li-ta Lo, James Ahrens, and Valerio Pascucci. Proceedings of the IEEE Symposium on Large-Scale Data Analysis and Visualization (LDAV). November 2014. Paris, France. Link

Volume-of-Fluid Interface Reconstruction Algorithms on Next Generation Computer Architectures. Marianne M. Francois, Li-ta Lo, and Christopher Sewell. Proceedings of the ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting and 12th International Conference on Nanochannels, Microchannels, and Minichannels. August 2014. Chicago, IL. Link

Data-Parallel Programming with PISTON and PINION. Presentation at the Programming Models and Applications Meeting. August 2014. Albuquerque, New Mexico.

Portable Parallel Halo and Center Finders for HACC. Presentation at the Oak Ridge Leadership Computing Facility Users' Meeting. July 2014. Oak Ridge, Tennessee. Link

PISTON. Guest lectures for Professor Hank Childs' multi-core parallel programming graduate class at the University of Oregon. January 2014. Link

Portable Data-Parallel Visualization and Analysis in Distributed Memory Environments. Christopher Sewell, Li-ta Lo, and James Ahrens. Proceedings of the IEEE Symposium on Large-Scale Data Analysis and Visualization (LDAV). October 2013. Atlanta, GA. Link

Research Challenges for Visualization Software. Hank Childs, Berk Geveci, Will Schroeder, Jeremy Meredith, Kenneth Moreland, Christopher Sewell, Torsten Kuhlen, and E. Wes Bethel. Computer Magazine. May 2013. pp. 34-42. Link

Portable Data-Parallel Visualization and Analysis Operators. Presentation at the GPU Technology Conference. March 2013. San Jose, California. Link

The SDAV Software Frameworks for Visualization and Analysis on Next-Generation Multi-Core Architectures. Christopher Sewell, Jeremy Meredith, Kenneth Moreland, Tom Peterka, Dave DeMarle, Li-ta Lo, James Ahrens, Robert Maynard, and Berk Geveci. The Seventh Workshop on Ultrascale Visualization at The International Conference for High-Performance Computing, Networking, Storage, and Analysis. November 2012. Salt Lake City, Utah. Link

The PISTON Software Framework for Visualization and Analysis on Next-Generation Multi-Core Architectures. Presentation at the Visualization Frameworks for Multi-Core and Many-Core Architectures Panel at The International Conference for High Performance Computing, Networking, Storage, and Analysis. November 2012. Salt Lake City, Utah.

Portability and Performance for Visualization and Analysis Operators Using the Data-Parallel PISTON Framework. Presentation at the Many-Core Libraries Tutorial and Code Sprint. September 2012. Clifton Park, New York.

PISTON: A Portable Cross-Platform Framework for Data-Parallel Visualization Operators. Li-ta Lo, Christopher Sewell, and James Ahrens. EGPGV: Proceedings of the Eurographics Symposium on Parallel Graphics and Visualization 2012. May 2012. Cagliari, Italy. Link

Portability and Performance for Visualization and Analysis Operators Using the Data-Parallel PISTON Framework. Presentation at the Accelerated High Performance Computing Symposium at the GPU Technology Conference. May 2012. San Jose, California.

Portability and Performance for Visualization and Analysis Operators Using the Data-Parallel PISTON Framework. Presentation at the Department of Energy Computer Graphics Forum. April 2012. Albuquerque, New Mexico.

PISTON: A Portable Cross-Platform Framework for Data-Parallel Visualization Operators. Presentation at the Workshop on Ultrascale Visualization at the International Conference for High-Performance Computing, Networking, Storage, and Analysis. November 2011. Seattle, Washington.



Medical Robotics

Intuitive Surgical, Sunnyvale, California
Senior Systems Analyst, January 2017 - Present

Consultant for several Bay Area medical device companies
June 2011 - January 2017

Hansen Medical, Mountain View, California
Senior Engineer, April 2007 - July 2009
Engineering Fellow, July 2009 - April 2011
Manager, Visualization Group, April 2010 - November 2010
Manager, Visualization and Controls Group, November 2010 - April 2011

Co-inventor of issued patent:
8,317,746 Automated Alignment. Christopher M. Sewell, Neal A. Tanner, and Teresa Miller.

Co-inventor on filed patent applications:
US20090076476 Systems and Methods Employing Force Sensing for Mapping Intra-Body Tissue
US20100125284 Registered Instrument Movement Integration
US20110015483 Endoscopic Robotic Catheter System
US20110295247 System and Method for Automated Minimally Invasive Therapy Using Radiometry
US20110295267 System and Method for Automated Tissue Structure Traversal
US20120071752 User Interface and Method for Operating a Robotic Medical System
US20120071894 Robotic Medical Systems and Methods
US20120191107 Systems and Methods for Positioning an Elongate Member Inside a Body
US20140275985 Systems and Methods for Localizing, Tracking, and/or Controlling Medical Instruments
US20140275988 Flexible Instrument Localization from Both Remote and Elongation Sensors
PCT/US2010/042080 Endoscopic Robotic Catheter System (foreign application combining 12/504,559; 12/504,564; and 12/504,569)



Surgical Simulation and Haptics

Advisor: Professor Ken Salisbury
Stanford Computer Science and Surgery
March 2003 to March 2007
Salisbury Group Homepage
Stanford AI and Robotics Lab Homepage
Computer Haptics and Active Interfaces Project Page
For videos and pictures see the Stanford Bone Simulation Page and the Stanford Challenge video

Providing Metrics and Performance Feedback in a Surgical Simulator. Christopher Sewell, Dan Morris, Nikolas H. Blevins, Sanjeev Dutta, Sumit Agrawal, Federico Barbagli, and Kenneth Salisbury. Computer Aided Surgery, Volume 13 Issue 2, March 2008, pp. 63-81. Link

Representing Fluid with Smoothed Particle Hydrodynamics in a Cranial Base Simulator. Wen Liu, Christopher Sewell, Nikolas Blevins, Kenneth Salisbury, Kenneth Bodin, and Nils Hjelte. Proceedings of Medicine Meets Virtual Reality (MMVR), Long Beach, CA, February 2008. Link

Automatic Performance Evaluation in Surgical Simulation. Christopher Sewell. PhD Dissertation, Stanford University, March 2007.

The Effect of Virtual Haptic Training on Real Surgical Drilling Proficiency. Christopher Sewell, Nikolas H. Blevins, Sumanth Peddamatham, Hong Z. Tan, Dan Morris, and Kenneth Salisbury. Proc. of IEEE World Haptics Conference, Tsukuba, Japan, March 2007, pp. 601-603. Link

Validating Metrics for a Mastoidectomy Simulator. Christopher Sewell, Dan Morris, Nikolas Blevins, Sumit Agrawal, Sanjeev Dutta, Federico Barbagli and Kenneth Salisbury. Proc. of Medicine Meets Virtual Reality (MMVR), Long Beach, CA, February 2007, IOS Press, pp. 421-426. Link

Evaluating Drilling and Suctioning Technique in a Mastoidectomy Simulator. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli and Kenneth Salisbury. Proc. of Medicine Meets Virtual Reality (MMVR), Long Beach, CA, February 2007, IOS Press, pp. 427-432. Link

Visuohaptic Simulation of Bone Surgery for Training and Evaluation. Dan Morris, Christopher Sewell, Federico Barbagli, Nikolas Blevins, Sabine Girod, and Kenneth Salisbury. IEEE Transactions on Computer Graphics and Applications, November 2006, pp. 48-57. Link

Achieving Proper Exposure in Surgical Simulation. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli and Kenneth Salisbury. Proceedings of Medicine Meets Virtual Reality (MMVR), Long Beach, CA, January 2006, IOS Press, pp. 497-502. Link

Metrics for a Mastoidectomy Simulator. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Poster at the Biomedical Computation at Stanford Symposium (BCATS), Stanford, CA, October 2005.

CHAI: An Open-Source Library for the Rapid Development of Haptic Scenes. Francois Conti, Federico Barbagli, Dan Morris, and Christopher Sewell. Demo at World Haptics, Pisa, Italy, March 2005.

A Simulator for Training a Full Mastoidectomy Procedure. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Demo at World Haptics, Pisa, Italy, March 2005.

Quantifying Risky Behavior in Surgical Simulation. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Proceedings of Medicine Meets Virtual Reality (MMVR), Long Beach, CA, January 2005, IOS Press, pp. 451-457. Link

Training the Cognitive and Stylistic Aspects of Surgery Through Simulation. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Poster at the Biomedical Computation at Stanford Symposium (BCATS), Stanford, CA, October 2004. Best Poster Award.

A Collaborative Virtual Environment for the Simulation of Temporal Bone Surgery. Dan Morris, Christopher Sewell, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Poster at the Biomedical Computation at Stanford Symposium (BCATS), Stanford, CA, October 2004.

An Event-Driven Framework for the Simulation of Complex Surgical Procedures. Christopher Sewell, Dan Morris, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Proceedings of the International Conference on Medical Imaging Computing and Computer Assisted Intervention (MICCAI), St. Malo, France, September 2004, Springer Lecture Notes in Computer Science, Vol. II, pp. 346-354. Link

A Collaborative Virtual Environment for the Simulation of Temporal Bone Surgery. Dan Morris, Christopher Sewell, Nikolas Blevins, Federico Barbagli, and Kenneth Salisbury. Proceedings of the International Conference on Medical Imaging Computing and Computer Assisted Intervention (MICCAI), St. Malo, France, September 2004, Springer Lecture Notes in Computer Science, Vol. II, pp. 319-327. Link

Haptic Interaction to Simulate Complex Surgical Procedures. Christopher Sewell, Kenneth Salisbury, Federico Barbagli, Tom Krummel, and Jean-Claude Latombe. Biomedical Computation at Stanford Symposium (BCATS), Stanford, CA, October 2003.


In the news

Getting the Feel of Surgery. Video from the Stanford Challenge Website. Video

Engineers, medical scholars team up to create new technologies to fight disease. Amy Adams. Stanford Report, October 22, 2003. Article

Getting a feel for surgery. Shawne Neeper. UCSC Science Notes, 2004. Article


Some lectures I've made for classes I've TA'ed

Proofs for the A* Search Algorithm Slides

Using CHAI for Developing Haptic Applications Slides

The God-Object / Proxy Haptic Rendering Algorithm, including Friction, Force Shading, and Textures Slides

Deformable Modeling Slides

Collision Detection Slides

Haptic Audio Slides



Protein Sequencing

Advisor: Dr. Olaf Lubeck
Los Alamos National Lab
May 2002 to August 2002

New Computational Approaches for De Novo Peptide Sequencing from MS/MS Experiments. Olaf Lubeck, Christopher Sewell, Sheng Gu, and Xian Chen. IEEE Proc. on Challenges in Biomedical Informatics, 2002, 90(12), 1868-1874. Link

Algorithm for Sequencing Proteins Using Mass Spectrometry Data. Oral presentation at Los Alamos National Laboratory Symposium, Los Alamos, NM, July 2002.



Computational Chemistry and Cell Modeling

Advisor: Professor Paul Lindahl
Texas A&M Chemistry
December 1998 to May 2002
Lindahl Group Homepage

Reduction and Methyl Transfer Kinetics of the Alpha Subunit from Acetyl Coenzyme A Synthase. Xiangshi Tan, Christopher Sewell, Qingwu Yang, Paul A. Lindahl. J. Am. Chem. Soc. (Comm.), 2003, 125(2), 318-319. Link

Analysis of Protein Homeostatic Regulatory Mechanisms in Perturbed Environments at Steady State. Christopher Sewell, Jeffrey J Morgan, and Paul A Lindahl. J. of Theoretical Bio. 2002, 215, 151-167. Link

Stopped-Flow Kinetics of the Methyl Group Transfer between Acetyl-Coenzyme A Synthase and the Corrinoid-Iron-Sulfur Protein from Clostridium thermoaceticum. Xiangshi Tan, Christopher Sewell, and Paul A. Lindahl. J. Am. Chem. Soc., June 2002, 124(22), 6277-6284. Link

Method for Modeling Complex Biochemical Processes from Semi-Fabricated Concentration-vs-Time Plots of All Reacting Components. Poster presentation at the Pfizer Chemical Undergraduate Research Symposium, Groton, CT, April 2002.

Method for Modeling Complex Biochemical Processes from Semi-Fabricated Concentration-vs-Time Plots of All Reacting Components. Presentation at the Texas A&M Student Research Week Symposium, College Station, TX, March 2002.

Kinetic Mechanism of Acetyl-CoA Synthase: Steady-State Synthesis at Variable CO/CO2 Pressures. Ernest L. Maynard, Christopher Sewell, and Paul A. Lindahl. J. Am. Chem. Soc., May 2001, 123(20), 4697-4703. Link

Analysis of Steady-State Protein Homeostatic Regulatory Mechanisms in Perturbed Environments. Christopher Sewell, Jeffrey J. Morgan, and Paul A. Lindahl. Poster presentation at the International Conference on Systems Biology, Pasadena, California, November 2001.

Method for Simulating the Kinetics of Cell Growth and Division at the Molecular Level. Christopher Sewell, Charles Johnson, Jeffrey J. Morgan, and Paul A. Lindahl. Poster presentation at the International Conference on Systems Biology, Pasadena, California, November 2001.

The Biocomplexity Project. Christopher Sewell. Undergraduate Honors Thesis, Texas A&M University, May 2001.

Analysis of Regulatory Mechanisms. Presentation at the Texas A&M Undergraduate Research Fellows Symposium, College Station, TX, April 2001.




Protein Folding

Advisor: Professor Nancy Amato
Texas A&M Computer Science
May 2001 to May 2002
Parasol Group Homepage

Contributed to Using Motion Planning to Map Protein Folding Landscapes and Analyze Folding Kinetics of Known Native Structures. Nancy Amato, Ken Dill, and Guang Song, Proceedings of the Sixth Annual Int'l Conf. on Computational Molecular Biology (RECOMB), April 2002, 2-11. (Not an author; mentioned in acknowledgements.) Link



Supercomputer Efficiency

El Paso Franklin High School and Lincoln Middle School
November 1993 to May 1998

Supercomputer Parallel Architectures: A Fifth-Year Study of Supercomputer Efficiency. Oral presentation at the National Junior Science and Humanities Symposium, Raleigh, NC, April 1998, and poster presentation at the Intel International Science and Engineering Fair, Fort Worth, TX, May 1998.