Anatomical studies

We have performed anatomical studies to measure muscle architecture, muscle moment arms, and joint kinematics.

• Murray, W. M., Buchanan, T.S., Delp, S.L. The isometric functional capacity of elbow muscles. Journal of Biomechanics, vol. 33, pp. 943-952, 2000. Download PDF Document

Strength and Coordination Measurements

We have studied the activation patterns of muscles in unimpaired subjects and in subjects with movement abnormalities by securing the limb to a load cell, asking subjects to match target loads displayed on a computer monitor, and recording the subjects’ EMG.

Surgical Navigation

We created and evaluated computer-integrated instrumentation that incorporates highly accurate measurement devices to locate joint centers, track surgical tools, and align prosthetic components.

• Delp, S.L., Loan, J.P., Basdogan, C., Rosen, J.M. Surgical simulation: an emerging technology for emergency medical training. Presence: Teleoperators and Virtual Environments, vol. 6, pp. 147-159, 1997. Download PDF Document

Three-Dimensional Muscle Modeling

We developed a mechanics-based formulation for representing three-dimensional skeletal muscle architecture and geometry, including a nonlinear constitutive model for muscle and tendon and graphics-based modeling techniques to characterize the three-dimensional trajectories of muscle fibers from medical image data.

• Webb, J.D., Blemker, S.S., Delp, S.L. 3D finite element models of shoulder muscles for computing lines of actions and moment arms. Computer Methods in Biomechanics and Biomedical Engineering, pp 1-9. Download PDF Document
• Blemker, S.S., Delp, S.L. Three-Dimensional Representation of Complex Muscle Architectures and Geometries. Annals of Biomedical Engineering, vol 33, pp. 661–673, 2005. Download PDF Document

Modeling and Simulation of Molecular Motors

We developed tools for creating course-grained geometric models of protein structures, performing molecular dynamic simulations to estimate physical properties, and running forward dynamic simulations of myosin during its power stroke.

• Parker, D., Bryant, Z., Delp, S.L. Coarse-grained structural modeling of molecular motors using multibody dynamics, Cellular and Molecular Bioengineering, vol 2, pp 366-374. Download PDF Document

Optogenetics and Neuromodulation

We apply optogenetics to control neural activity in the peripheral nervous system. We have achieved light-mediated activation of motor neurons to stimulate muscle contraction, and we are developing methods for inhibition of neural activity to control spasticity and pain.

• Christensen, A.J., Iyer, S.M., Francois, A., Vyas, S., Ramakrishnan, C., Vesuna, S., Deisseroth, K., Scherrer, G., Delp, S.L. In vivo interrogation of spinal mechanosensory circuits. Cell Reports, 17:1699-1710, 2016. Download PDF file
• Iyer, S.M., Vesuna, S., Ramakrishnan, C., Huynh, K., Young, S., Berndt, A., Lee, S.Y., Gorini, C.J., Deisseroth, K., Delp, S.L. Optogenetic and chemogenetic strategies for sustained inhibition of pain Scientific Reports, 6:30570 Download PDF file
• Ferenczi E.A., Vierock J., Atsuta-Tsunoda K., Tsunoda S.P., Ramakrishnan C., Gorini C., Thompson K., Lee S.Y., Berndt A., Perry C., Minniberger S., Vogt A., Mattis J., Prakash1 R., Delp S.L., Deisseroth K., Peter Hegemann. Optogenetic approaches addressing extracellular modulation of neural excitability. Scientific reports, 6, 2016. Download PDF Document
• Berndt A., Lee S.Y., Wietek J., Ramakrishnan C., Steinberg E.E., Rashid A.J., Kim H., Park S., Santoro A., Frankland P.W., Iyer S.M., Pak S., Ahrlund-Richter S., Delp S.L., Malenka R.C., Josselyn S.A., Carlen M., Hegemann P., Deisseroth K. Structural foundations of optogenetics: Determinants of channelrhodopsin ion selectivity. Proceedings of the National Academy of Sciences, 201523341, 2015. Download PDF Document
• Montgomery, K.L., Iyer S.M., Christensen A.J., Deisseroth K., Delp S.L. Beyond the brain: Optogenetic control in the spinal cord and peripheral nervous system. Science Translational Medicine, 8(337), 337rv5-337rv5, 2016. Download PDF Document
• Montgomery, K.L., Yeh, A.J., Ho, J.S., Tsao, V., Iyer, S.M., Grosenick, L., Ferenczi, E.A., Tanabe, Y., Deisseroth, K., Delp, S.L., Poon, A.S.Y. Wirelessly powered, fully internal optogenetics for brain, spinal and peripheral circuits in mice. Nature Methods, vol 12, pp 969-974.  Download PDF Document
• Iyer, S.M., Delp, S.L. Optogenetic Regeneration. Science, vol 344, pp 44-45. Download PDF Document
• Iyer, S.M., Montgomery, K.L., Towne, C., Lee, S.Y., Ramakrishnan, C., Deisseroth, K., Delp, S.L. Virally mediated optogenetic excitation and inhbition of pain in freely moving nontransgenic mice. Nature Biotechnology, vol 32, pp 274-278. Download PDF Document
• Delp, S.L. Studying Circuits with Therapy in Mind: Therapy for the Periphery. Cell, vol 156, pp 862. Download PDF Document
• Liske, H., Qian, X., Anikeeva, P., Deisseroth, K., Delp, S. Optical control of neuronal excitation and inhibition using a single opsin protein, ChR2. Scientific Reports, vol 3. Download PDF Document