A Multivariate Method for Analysing Time and Space Components of Highly Disparate Movement Trajectories

Abstract

The difficulties in performing manual control tasks under visual-motor mismatch are well documented. For example, laparoscopic surgeons must operate in an environment where a motor movement and the visual feedback of that same movement are ordinarily misaligned with respect to each other, increasing the risk of control errors. To complement conventional global measures of motor performance, which provide insight into spatial and/or temporal performance averaged over several trials, a bivariate dynamic measure encompassing joint time and space components is proposed. These two components are the instantaneous velocity and movement efficiency, derived from recorded movement trajectories. The dynamic measure consists of a graphical representation of the bivariate data, in conjunction with a non-parametric statistical analysis. An example is given of the dynamic measure applied to movement trajectories from an investigation involving simulated laparoscopic pointing under visual-motor mismatch. Results from both global and dynamic measures are discussed, along with limitations of the multivariate dynamic measure.

References

Cunningham

(1989). Aiming error under transformed spatial mappings suggests a structure for visual–motor maps Journal of Experimental Psychology: Human Perception and Performance, 15(3), 493–506.

Cunningham

Vardi

(1990). A vector-sum process produces curved aiming paths under rotated visual-motor mappings Biological Cybernetics, 64(2), 117–128.

(2002). An investigation of the potential benefits of history trail displays for human spatial performance under different visual-motor mappings. Unpublished MASc thesis, University of Toronto, Toronto.

Ellis

Tyler

Kim

Stark

(1992). Three dimensional tracking with misalignment between display and control axes SAE Transactions: Journal of Aerospace, 100–1, 985–989.

Field

(2005). Discovering Statistics Using SPSS: Sage Publications Ltd.

Guru

K. A.

Kuvshinoff

B. W.

Pavlov-Shapiro

Bienko

M. B.

Aftab

M. N.

Brady

W. E.

(2007). Impact of robotics and laparoscopy on surgical skills: A comparative study Journal of the American College of Surgeons, 204(1), 96–101.

Helmholtz

H. v.

(1962). A treatise on physiological optics. New York: Dover. (Original work published 1866).

Katz

McSweeney

(1980). A multivariate Kruskal-Wallis test with post hoc procedures Multivariate Behavioral Research, 15(3), 281–297.

Kim

Tendick

Stark

(1987). Visual enhancements in pick-and-place tasks: Human operators controlling a simulated cylindrical manipulator IEEE Journal of Robotics and Automation, 3(5), 418–425.

10.

MacKenzie

I. S.

Tatu

Miika

(2001). Accuracy measures for evaluating computer pointing devices, Proceedings of the ACM conference on Human factors in computing systems - CHI 2001 (pp. 9–16). New York: ACM.

11.

Morton

(2004). An investigation of an augmented reality display of predictive and historical trajectory information for manual control under misaligned visual-motor mappings. Unpublished MASc thesis, University of Toronto, Toronto.

12.

Soung

Yee A.

(2008). An investigation of the effect of display augmentation with instantaneous movement information on telemanipulation performance under visual-motor mismatch. Unpublished MASc thesis, University of Toronto, Toronto.

13.

Tendick

Cavusoglu

M. C.

(1997). Human-machine interfaces for minimally invasive surgery, Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology society (Vol. 6, pp. 2771–2776).