Paul Marasco Laboratory

Research

Overview

Neural-Machine Interface and Prosthetics

A neural-machine interface is a machine, such as a bionic limb, that has a connection with the wearer’s brain—in this case, the user’s limb nerves. Our prosthetics utilize a neural-machine interface that surgically reconnects amputated nerves to new muscle and skin sites. The nerves of these amputees are not physically connected to the machine; instead, the bionic prosthetic picks up electrical signals from the reinnervated muscles and small robots push and vibrate against the user’s skin containing the reintegrated nerves.

When an amputee thinks about moving their bionic limb, nerve impulses travel from their brain to the reintegrated nerve endings in their muscles. The mechanical components of the muscles generate electricity when they contract which acts like a biological amplifier; intensifying the nerve impulses so that they control the actions of the prosthetic.

The prosthetic is bidirectional, meaning that it also receives information and relays it back to the nerves. Tactors, or touch robots, are integrated into the limb. These robots send pressure and vibrations through the skin to communicate with their reintegrated nerves which provides information about the prosthetic limb to the user’s brain. The information includes the prosthetic’s movement in space, the shape of the hand’s grip, and the feel of objects that the hand is touching.

Prosthetic Embodiment

We study ownership and agency, and use these concepts to engineer prosthetics that cognitively and perceptually integrate with the user.

Ownership is the sense that one occupies their body, and that the parts of one’s body belong to them. In our research, we use physiologically relevant artificial touch to help amputees feel that their prosthetic limb is a naturally integrated part of their body.

Agency is the feeling that you are the author of your actions. We use perceptual illusions of movement that are coupled to the intended movement of a prosthesis to provide amputees a sense of agency over their devices.

Together the experience of ownership and agency combine to provide a more integrated sense of overall prosthetic embodiment. This provides the amputees with a clear feeling that their prosthetic limb is a natural part of their own body.

Functional Metrics for Humans with Bidirectionally Integrated Prosthetic Limbs: Upper Limb Sensory-Motor Integration Assessments

The Laboratory for Bionic Integration is working closely with Dr. Jacqueline Hebert, MD, FRCPC at the University of Alberta; and Dr. Jon Sensinger, PhD, PEng of the University of New Brunswick to develop a suite of metrics as sophisticated and effective as the devices that they assess. These tests help map system function, so that they may be used as tools to inform technology design, implementation, and translation. The metrics are designed to not have a ceiling effect so that comparisons can be made with able-bodied users. They are rooted in science (psychophysics, cognition/perception, and kinematics) yet they represent functional, real-world tasks that are clinically applicable to users of advanced upper limb sensory-motor integration technologies.

Key Concepts

Sensory nervous system: The nerves responsible for gathering information from your senses
Neuroplasticity: The ability of the brain to reorganize
Embodiment: The feeling that the parts of your body belong to you
Authorship: The feeling that you are in control of your body’s actions
Cognitive engagement: Amputees perceive that their prosthetic limb is under their control, and a part of their body

Functional Metrics Development

The Laboratory for Bionic Integration is working closely with Jacqueline Hebert, MD, FRCPC, at the University of Alberta and Jon Sensinger, PhD, PEng, of the University of New Brunswick to develop a suite of metrics as sophisticated and effective as the devices that they assess. These tests help map system function, so that they may be used as tools to inform technology design, implementation, and translation. The metrics are designed to not have a ceiling effect in comparison with able-bodied users. They are rooted in functional, real-world tasks and are clinically applicable to users of advanced upper limb sensory-motor integration technologies.

The metrics suite includes:

	1. GRIP: Grasping Relative Index of Performance Developed by the Laboratory for Bionic Integration The principle tasks for upper-limb prosthesis use involve grasping, gripping, or squeezing. The ability to quickly and accurately apply a desired force is critical for appropriate manual manipulation, from handholding to heavy lifting, and is necessary for obtaining fluid, natural use of a prosthetic hand. Fitts’ law is a widely applicable descriptive model relating the time required to achieve a target to movement size and accuracy. By applying this law to grip forces across the dynamic range of a device we can quantify a relative effective accuracy and index of performance irrespective of control scheme or feedback modality.
	2. PEP: Prosthesis Efficiency and Profitability Developed by the Laboratory for Bionic Integration Humans use their hands to acquire and manipulate objects for a multitude of activities of daily living. This object acquisition and manipulation involves seam-less interaction between motor control, touch and proprioception. Upper limb prosthetic devices are designed to replace this lost functionality and their intrinsic utility is reflected in their relative functional efficiency. Accepted methodologies from evolutionary ecology provide a mathematical model-based framework for assessing efficiency and profitability in complex biological systems. In this metric, optimal foraging theory is used as a platform to objectively assess the searching, reaching, grasping, manipulating and decision-making movements involved with prosthesis use which directly reflect foraging tasks and behaviors.
	3. GaMA: Gaze & Movement Assessment Developed by the Hebert Lab As our primary source of sensory information, the movement of our eyes to specific locations is intimately tied to the demands of a task and is an excellent correlate of where we are attending. Visual attention is an integral component of motor performance expected to change with accurate sensory feedback from the prosthesis and intuitive motor control. This metric combines motion tracking and eye tracking during simulated real-world tasks, and enables 3D gaze vector rendering by integrating environmental modeling and the representation of real world objects. This metric identifies the motion of the prosthesis, compensatory body movements and simultaneous visual gaze behavior during performance tasks in integrated 3D space, as well as the location and movement of task-critical objects. Metrics output include upper limb and hand kinematic measures as well as standard measures of visual attention.
	4. CBI: Control Bottleneck Index Developed by the Sensinger Lab Your brain sends efferent signals which are corrupted by noise. It receives afferent signals from many sources. It forms models that help it predict control and interpret feedback. Good performance can be achieved with many combinations of these three factors, and performance may be limited by a bottleneck in any one of them. In that case, improvements in one of the other factors may not lead to significant improvements in performance until the bottleneck is relieved. The purpose of this metric is to identify the bottleneck in that process for a given task, and to evaluate the contribution of a particular control strategy or sensory feedback modality independent of that bottleneck. This task is appropriate to assess control source and feedback fidelity.
	5. PIC: Prosthesis Incorporation Developed by the Sensinger Lab The goal of this metric is to quantitatively measure how much a prosthesis has been incorporated into the body schema. Device incorporation is a good indication that control and sensory feedback are intuitive, synchronized, and meaningful. This metric uses a cross-modal congruency effect paradigm to evaluate prosthesis incorporation, in which the ability of a person to ignore one form of feedback in favor of another is assessed. The metric provides an index that can be assessed quickly and accurately using a simple standardized setup. This task is appropriate to assess control source and tactile feedback fidelity.

Using the Metrics Suite in Your Research

If you are interested in using the functional metrics suite in your research, please email Dr. Paul Marasco at [email protected].

Current Projects

Functional Metrics for Humans with Bidirectionally Integrated Prosthetic Limbs

We are working in conjunction with the University of Alberta and the University of New Brunswick on development and delivery of a suite of validated functional metrics for bi-directionally integrated advanced prosthetic limb systems. The metrics will be adaptable to both advanced and current standard-of-care prosthetics, clinically implementable with a minimum requirement of technological expertise to operate, flexible to account for numerous systems approaches, sensitive to system performance, and reflective of requirements for quantifying different control and feedback strategies.

Defense Advanced Research Project Agency (DARPA), Department of Defense, Contract # N66001-15-C-4015

Publications:

P. D. Marasco, J. S. Hebert, J. W. Sensinger, D. T. Beckler, Z. C. Thumser, A. W. Shehata, H. E. Williams, K. R. Wilson. "Neurorobotic fusion of prosthetic touch, kinesthesia, and movement in bionic upper limbs promotes intrinsic brain behaviors." Sci. Robot. 6, eabf3368 (2021).

D. T. Beckler, Z. C. Thumser, J. S. Schofield, P. D. Marasco. “Reliability in evaluator-based tests: using simulation-constructed models to determine contextually relevant agreement thresholds.” BMC Med Res Methodol. 2018; 18:141.

P. D. Marasco, J. S. Hebert, J. W. Sensinger, C. E. Shell, J. S. Schofield, Z. C. Thumser, R. Nataraj, D. T. Beckler, M. R. Dawson, D. H. Blustein, S. Gill, B. D. Mensh, R. Granja-Vazquez, M. D. Newcomb, J. P. Carey, B. M. Orzell. "Illusory movement perception improves motor control for prosthetic hands." Sci. Transl. Med. 10, eaao6990 (2018).

Blustein, Daniel H., and Jonathon W. Sensinger. "Validation of a constrained-time movement task for use in rehabilitation outcome measures." In Rehabilitation Robotics (ICORR), 2017 International Conference on, pp. 1183-1188. IEEE, 2017.

Wilson, Adam W., Daniel H. Blustein, and Jon W. Sensinger. "A third arm—Design of a bypass prosthesis enabling incorporation." In Rehabilitation Robotics (ICORR), 2017 International Conference on, pp. 1381-1386. IEEE, 2017.

Physiologically Relevant Prosthetic Limb Movement Feedback for Upper and Lower Extremity Amputees

We are developing a wearable robotic perceptual feedback system to provide vibrational input as part of a prosthetic socket interface. We are using cognitive/perceptual approaches to provide physiologically relevant vibration-induced joint movement feedback in upper and lower limbs for normal amputees without a neural-machine-interface.

Department of Defense, Congressionally Directed Medical Research Program (CDMRP) Clinical and Rehabilitative Medicine Research Program (CRMRP) Grant #MR140156

Advanced Materials to Improve Moisture Management for Prosthetic Socket Liners

We are working to develop a new prosthetic socket liner material to transport and sequester sweat away from an amputee’s skin. The number of amputees, particularly double- and triple-amputees, in our veteran population has steadily increased over the last decade. Meanwhile, advances in prosthesis technology have produced devices with increasing functional potential of which our veteran amputee users want to take full advantage. In contrast, conventional silicone socket liners have advanced relatively little, including an undesirable tendency to accumulate sweat during use, particularly for physically active amputees. A liner material which keeps this moisture away from the user’s skin would not only improve comfort and hygiene, but also the critically-important fit and thus the overall performance of the prosthesis.

Department of Veterans Affairs, Merit Review, 1 I01 RX001833-01A2

Pulsed Electromagnetic Frequency (PEMF) Stimulation of Mechanosensory Nerves Affecting Bone

We are investigating the use of differing fundamental frequency and magnetic field strength characteristics of Pulsed Electromagnetic Field (PEMF) treatment on mechanosensory nerve action potentials in the hind limbs of skeletally mature rats.
Orthofix, Inc. sponsored research agreement, co-investigator 

Recent Projects

Restoring Upper Limb Movement Sense to Amputees; A Move Towards Natural Control of Prosthetic Limbs

We are using cognitive and perceptual approaches and a direct neural-machine interface to provide prosthetic limbs with a physiologically relevant sense of complex synergistic hand movements.

National Institutes of Health (NIH) Director’s Transformative R01 Research Award, 1R01NS081710 – 01

Proprioception in Preclinical Model Cortex to Examine Sensory Feedback for Prosthetics

In this project we used a rat model to investigate how kinesthesia (the sense of limb movement) is organized in the brain.

VA RR&D Career Development Award, Level-2 No. A7253W

Publication:
Marasco PD, Bourbeau DJ, Shell CE, Granja-Vazquez R, Ina JG (2017)."The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion." PLoS ONE 12(11): e0188559.

A Touch Feedback Tactor Array System for Long-term Implementation of Physiologically Relevant Cutaneous Touch with Prosthetic Limbs

We have developed and implemented a sensory feedback system for prosthetic limbs that is integrated with the amputee’s nerves to provide physiologically relevant cutaneous feedback. It was designed, built, and packaged for long-term take-home use and is being used to examine the malleability of representational plasticity and cognitive effects of visual-tactile integration with use over one year.

Defense Advanced Research Project Agency (DARPA), Department of Defense, 61732-LS-DRP, Under P-1108-114403/DARPA-BAA-11-08 Reliable Peripheral Interfaces (RPI)

Selected Publications

View publications for Paul Marasco, PhD
(Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)

P. D. Marasco, J. S. Hebert, J. W. Sensinger, D. T. Beckler, Z. C. Thumser, A. W. Shehata, H. E. Williams, K. R. Wilson, Neurorobotic fusion of prosthetic touch, kinesthesia, and movement in bionic upper limbs promotes intrinsic brain behaviors. Sci. Robot. 6, eabf3368 (2021).

Schofield JS, Battraw MA, Parker ASR, Pilarski PM, Sensinger JW, Marasco PD. Embodied Cooperation to Promote Forgiving Interactions With Autonomous Machines. Front Neurorobot. 2021 Apr 9;15:661603. doi: 10.3389/fnbot.2021.661603. eCollection 2021. PMID: 33897401 Free PMC article. 

Keri MI, Shehata AW, Marasco PD, Hebert JS, Vette AH. A Cost-Effective Inertial Measurement System for Tracking Movement and Triggering Kinesthetic Feedback in Lower-Limb Prosthesis Users. Sensors (Basel). 2021 Mar 6;21(5):1844. doi: 10.3390/s21051844. PMID: 33800790 Free PMC article. 

Ferrari F, Shell CE, Thumser ZC, Clemente F, Plow EB, Cipriani C, Marasco PD. Proprioceptive Augmentation With Illusory Kinaesthetic Sensation in Stroke Patients Improves Movement Quality in an Active Upper Limb Reach-and-Point Task. Front Neurorobot. 2021 Mar 1;15:610673. doi: 10.3389/fnbot.2021.610673. eCollection 2021.PMID: 33732129 Free PMC article. 

Shell CE, Christie BP, Marasco PD, Charkhkar H, Triolo RJ. Lower-Limb Amputees Adjust Quiet Stance in Response to Manipulations of Plantar Sensation. Front Neurosci. 2021 Feb 18;15:611926. doi: 10.3389/fnins.2021.611926. eCollection 2021. PMID: 33679300 Free PMC article. 

Schofield JS, Shell CE, Beckler DT, Thumser ZC, Marasco PD. Long-Term Home-Use of Sensory-Motor-Integrated Bidirectional Bionic Prosthetic Arms Promotes Functional, Perceptual, and Cognitive Changes. Front Neurosci. 2020 Feb 19;14:120. doi: 10.3389/fnins.2020.00120. eCollection 2020. PMID: 32140096 Free PMC article. 

Fabrication and application of an adjustable myoelectric transhumeral prosthetic socket. Schofield JS, Schoepp KR, Stobbe M, Marasco PD, Hebert JS. Prosthet Orthot Int. 2019 Oct;43(5):564-567. doi: 10.1177/0309364619836353. Epub 2019 Mar 29. PMID: 30922181 

Ereifej ES, Shell CE, Schofield JS, Charkhkar H, Cuberovic I, Dorval AD, Graczyk EL, Kozai TDY, Otto KJ, Tyler DJ, Welle CG, Widge AS, Zariffa J, Moritz CT, Bourbeau DJ, Marasco PD. Neural engineering: the process, applications, and its role in the future of medicine. J Neural Eng. 2019 Nov 12;16(6):063002. doi: 10.1088/1741-2552/ab4869. PMID: 31557730 Free PMC article. 

Christie BP, Charkhkar H, Shell CE, Marasco PD, Tyler DJ, Triolo RJ. Visual inputs and postural manipulations affect the location of somatosensory percepts elicited by electrical stimulation. Sci Rep. 2019 Aug 12;9(1):11699. doi: 10.1038/s41598-019-47867-1. PMID: 31406122 Free PMC article. 

Shehata AW, Keri MI, Gomez M, Marasco PD, Vette AH, Hebert JS. Skin Stretch Enhances Illusory Movement in Persons with Lower-Limb Amputation. IEEE Int Conf Rehabil Robot. 2019 Jun;2019:1233-1238. doi: 10.1109/ICORR.2019.8779477. PMID: 31374798 

Beckler DT, Thumser ZC, Schofield JS, Marasco PD. Using sensory discrimination in a foraging-style task to evaluate human upper-limb sensorimotor performance. Sci Rep. 2019 Apr 9;9(1):5806. doi: 10.1038/s41598-019-42086-0. PMID: 30967581 Free PMC article. 

Schofield JS, Shell CE, Thumser ZC, Beckler DT, Nataraj R, Marasco PD. Characterization of the Sense of Agency over the Actions of Neural-machine Interface-operated Prostheses. J Vis Exp. 2019 Jan 7;(143). doi: 10.3791/58702. PMID: 30663709 

Beckler DT, Thumser ZC, Schofield JS, Marasco PD. Reliability in evaluator-based tests: using simulation-constructed models to determine contextually relevant agreement thresholds. BMC Med Res Methodol. 2018 Nov 19;18(1):141. doi: 10.1186/s12874-018-0606-7. PMID: 30453897 Free PMC article. 

Downey JE, Weiss JM, Flesher SN, Thumser ZC, Marasco PD, Boninger ML, Gaunt RA, Collinger JL. Implicit Grasp Force Representation in Human Motor Cortical Recordings. Front Neurosci. 2018 Oct 31;12:801. doi: 10.3389/fnins.2018.00801. eCollection 2018. PMID: 30429772 Free PMC article. 

Schoepp KR, Schofield JS, Home D, Dawson MR, Lou E, Keri M, Marasco PD, Hebert JS. Real time monitoring of transtibial elevated vacuum prostheses: A case series on socket air pressure. PLoS One. 2018 Oct 22;13(10):e0202716. doi: 10.1371/journal.pone.0202716. eCollection 2018. PMID: 30346953 Free PMC article.

Charkhkar H, Shell CE, Marasco PD, Pinault GJ, Tyler DJ, Triolo RJ. High-density peripheral nerve cuffs restore natural sensation to individuals with lower-limb amputations. J Neural Eng. 2018 Oct;15(5):056002. doi: 10.1088/1741-2552/aac964. Epub 2018 Jun 1. PMID: 29855427 

Thumser ZC, Slifkin AB, Beckler DT, Marasco PD. Fitts' Law in the Control of Isometric Grip Force With Naturalistic Targets. Front Psychol. 2018 Apr 26;9:560. doi: 10.3389/fpsyg.2018.00560. eCollection 2018. PMID: 29773999 Free PMC article. 

Marasco PD, Hebert JS, Sensinger JW, Shell CE, Schofield JS, Thumser ZC, Nataraj R, Beckler DT, Dawson MR, Blustein DH, Gill S, Mensh BD, Granja-Vazquez R, Newcomb MD, Carey JP, Orzell BM. Illusory movement perception improves motor control for prosthetic hands. Sci Transl Med. 2018 Mar 14;10(432):eaao6990. doi: 10.1126/scitranslmed.aao6990.PMID: 29540617 Free PMC article. 

McDaniel J, Lombardo LM, Foglyano KM, Marasco PD, J Triolo R. Cycle Training Using Implanted Neural Prostheses: Team Cleveland. Eur J Transl Myol. 2017 Dec 6;27(4):7087. doi: 10.4081/ejtm.2017.7087. eCollection 2017 Dec 5. PMID: 29299221 Free PMC article. 

Marasco PD. Using proprioception to get a better grasp on embodiment. J Physiol. 2018 Jan 15;596(2):133-134. doi: 10.1113/JP275468. Epub 2017 Dec 28. PMID: 29194626 Free PMC article. 

Marasco PD, Bourbeau DJ, Shell CE, Granja-Vazquez R, Ina JG. The neural response properties and cortical organization of a rapidly adapting muscle sensory group response that overlaps with the frequencies that elicit the kinesthetic illusion. PLoS One. 2017 Nov 28;12(11):e0188559. doi: 10.1371/journal.pone.0188559. eCollection 2017. PMID: 29182648 Free PMC article. 

McDaniel J, Lombardo LM, Foglyano KM, Marasco PD, Triolo RJ. Setting the pace: insights and advancements gained while preparing for an FES bike race. J Neuroeng Rehabil. 2017 Nov 17;14(1):118. doi: 10.1186/s12984-017-0326-y. PMID: 29149885 Free PMC article. 

Schofield JS, Schoepp KR, Williams HE, Carey JP, Marasco PD, Hebert JS. Characterization of interfacial socket pressure in transhumeral prostheses: A case series. PLoS One. 2017 Jun 2;12(6):e0178517. doi: 10.1371/journal.pone.0178517. eCollection 2017.PMID: 28575012 Free PMC article. 

Schofield JS, Evans KR, Hebert JS, Marasco PD, Carey JP. The effect of biomechanical variables on force sensitive resistor error: Implications for calibration and improved accuracy. J Biomech. 2016 Mar 21;49(5):786-792. doi: 10.1016/j.jbiomech.2016.01.022. Epub 2016 Feb 9. PMID: 26903413 Free PMC article. 

Hebert JS, Olson JL, Morhart MJ, Dawson MR, Marasco PD, Kuiken TA, Chan KM. Novel targeted sensory reinnervation technique to restore functional hand sensation after transhumeral amputation. IEEE Trans Neural Syst Rehabil Eng. 2014 Jul;22(4):765-73. doi: 10.1109/TNSRE.2013.2294907. Epub 2013 Dec 18. PMID: 24760915 

Fox JD, Capadona JR, Marasco PD, Rowan SJ. (2013) Bioinspired Water-Enhanced Mechanical Gradient Nanocomposite Films That Mimic the Architecture and Properties of the Squid Beak. J Am Chem Soc.

Marasco PD, Kim K, Colgate JE, Peshkin MA, Kuiken TA. (2011) Robotic touch shifts perception of embodiment to a prosthesis in Targeted Reinnervation amputees. Brain. 134: 747-58

Marasco PD, and Kuiken TA. (2010) Amputation with median nerve redirection (Targeted Reinnervation) reactivates forepaw barrel subfield in rats. Journal of Neuroscience 30:16008-16014.

Marasco PD, Schultz AE, Kuiken TA. (2009) Sensory capacity of reinnervated skin after redirection of amputated upper limb nerves to the chest. Brain. 132(pt 6): 1441-8.

Schultz AE, Marasco PD, Kuiken TA. (2009) Vibrotactile detection thresholds for chest skin of amputees following targeted reinnervation surgery. Brain Research. 1251:121-9.

Kuiken TA*, Marasco PD*, Lock BA, Harden RN, Dewald JP. (2007) Redirection of cutaneous sensation from the hand to the chest skin of human amputees with targeted reinnervation. Proceedings of the National Academy of Sciences U S A. 104: 20061-6. (*these authors contributed equally to this work)

Marasco PD, Tsuruda PR, Bautista DM, Catania KC. (2007) The fine structure of Eimer’s organ in the coast mole (Scapanus orarius). Anatomical Record. 290: 437-448.

Marasco PD, and Catania KC. (2007) Response properties of primary afferents supplying Eimer’s organ. Journal of Experimental Biology. 210: 765-780

Kuiken TA, Miller LA, Lipschutz RD, Lock BA, Stubblefield K, Marasco PD, Zhou P, Dumanian GA. (2007) Targeted reinnervation for enhanced prosthetic arm function in a woman with proximal amputation. The Lancet 369: 371-380

Marasco PD, Tsuruda PR, Bautista DM, Julius D, Catania KC. (2006) Neuroanatomical evidence for segregation of nerve fibers conveying light touch and pain sensation in Eimer's organ of the mole. Proceedings of the National Academy of Sciences U S A. 103: 9339-9344

Henry EC, Marasco PD, Catania KC. (2005) Plasticity of the cortical dentition representation after tooth extraction in naked mole-rats. Journal of Comparative Neurology 485: 64-74

Appel, B., P. Marasco, L. McClung and A.J. Latimer (2003) lunatic fringe Regulates delta- notch induction of hypochord in zebrafish. Developmental Dynamics 228: 281-286

Crish, S.D., C. Comer, P. D. Marasco and K.C. Catania (2003) Somatosensation in the superior colliculus of the star-nosed mole. Journal of Comparative Neurology 464: 415-425

Book Chapters

Marasco PD., “Targeted Sensory Reinnervation”, chapter 8, in: Targeted Muscle Reinnervation, Kuiken and Schultz, Eds. CRC Press Taylor & Francis Group, Boca Raton, 2014 ISBN 978-1-4398-6080-9

Capadona, JR and PD Marasco “Brain Response to Neural Prostheses”, chapter 6, in: The Textbook of Neural Repair, Seltzer et al. Eds, 2nd Edition. (in-press)