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Pulse-step models of control strategies for dynamic ocular accommodation and disaccommodation.
Vision Res. 2006 Jan; 46(1-2):242-58.VR

Abstract

Dynamic properties and control strategies of step responses by accommodation and disaccommodation differ from one another. Peak velocity of accommodation increases with response magnitude, while peak velocity and peak acceleration of disaccommodation increase with starting position. These dynamic properties can be modeled as control strategies that use independent acceleration-pulse and velocity-step components that are integrated respectively into phasic-velocity signals that control movement and tonic-position signals that control magnitude. Accommodation is initiated toward its final destination by an acceleration-pulse whose width increases with response magnitude to increase peak velocity. Disaccommodation is initiated toward a default destination (the far point) by an acceleration-pulse whose height increases with dioptric distance of the starting position to increase peak velocity and peak acceleration. Both responses are completed and maintained by tonic-position signals whose amplitudes are proportional to the final destination. Mismatched amplitudes of phasic-velocity and tonic-position signals in disaccommodation produce unstable step responses.

Authors+Show Affiliations

School of Optometry, University of California at Berkeley, Berkeley, CA 94720, USA. schor@socrates.berkeley.eduNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural

Language

eng

PubMed ID

16289198

Citation

Schor, Clifton M., and Shrikant R. Bharadwaj. "Pulse-step Models of Control Strategies for Dynamic Ocular Accommodation and Disaccommodation." Vision Research, vol. 46, no. 1-2, 2006, pp. 242-58.
Schor CM, Bharadwaj SR. Pulse-step models of control strategies for dynamic ocular accommodation and disaccommodation. Vision Res. 2006;46(1-2):242-58.
Schor, C. M., & Bharadwaj, S. R. (2006). Pulse-step models of control strategies for dynamic ocular accommodation and disaccommodation. Vision Research, 46(1-2), 242-58.
Schor CM, Bharadwaj SR. Pulse-step Models of Control Strategies for Dynamic Ocular Accommodation and Disaccommodation. Vision Res. 2006;46(1-2):242-58. PubMed PMID: 16289198.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Pulse-step models of control strategies for dynamic ocular accommodation and disaccommodation. AU - Schor,Clifton M, AU - Bharadwaj,Shrikant R, Y1 - 2005/11/09/ PY - 2005/07/15/received PY - 2005/08/29/revised PY - 2005/09/14/accepted PY - 2005/11/18/pubmed PY - 2006/2/10/medline PY - 2005/11/18/entrez SP - 242 EP - 58 JF - Vision research JO - Vision Res. VL - 46 IS - 1-2 N2 - Dynamic properties and control strategies of step responses by accommodation and disaccommodation differ from one another. Peak velocity of accommodation increases with response magnitude, while peak velocity and peak acceleration of disaccommodation increase with starting position. These dynamic properties can be modeled as control strategies that use independent acceleration-pulse and velocity-step components that are integrated respectively into phasic-velocity signals that control movement and tonic-position signals that control magnitude. Accommodation is initiated toward its final destination by an acceleration-pulse whose width increases with response magnitude to increase peak velocity. Disaccommodation is initiated toward a default destination (the far point) by an acceleration-pulse whose height increases with dioptric distance of the starting position to increase peak velocity and peak acceleration. Both responses are completed and maintained by tonic-position signals whose amplitudes are proportional to the final destination. Mismatched amplitudes of phasic-velocity and tonic-position signals in disaccommodation produce unstable step responses. SN - 0042-6989 UR - https://www.unboundmedicine.com/medline/citation/16289198/Pulse_step_models_of_control_strategies_for_dynamic_ocular_accommodation_and_disaccommodation_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0042-6989(05)00485-2 DB - PRIME DP - Unbound Medicine ER -