Finger reach envelope using the marching cubes method

Johnson, Ross; Yang, Jingzhou; Long, J. D.

doi:10.1504/ijhfms.2010.036794

Cited by 2 publications

(1 citation statement)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several models define the abilities of the hand in terms of reachable 3D spaces and have the potential to quantify handobject interactions (Dias et al, 2009;Dragulescu et al, 2007;Johnson et al, 2010;Kuo et al, 2009). The weighted fingertip space (WFS) model developed by the authors is one such model that Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/jbiomech www.JBiomech.com calculates the reachable spaces and weights the spaces according to kinematic functional abilities (Leitkam et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Mapping kinematic functional abilities of the hand to three dimensional shapes for inclusive design

Leitkam

Bix

Fuente

et al. 2015

Journal of Biomechanics

View full text Add to dashboard Cite

Loss of hand function can have adverse effects on an individual's ability to maintain independence. The ability to perform daily activities, such as food preparation and medication delivery, is dependent on the hand's ability to grasp and manipulate objects. Therefore, the goal of this research was to demonstrate that three dimensional (3D) modeling of hand function can be used to improve the accessibility of handheld objects for individuals with reduced functionality through informed design. Individual models of hand functionality were created for 43 participants and group models were developed for groups of individuals without (Healthy) and with reduced functionality due to arthritis (RFA) of the hand. Cylindrical models representative of auto-injectors of varying diameters were analyzed in 3D space relative to hand function. The individual model mappings showed the cylinder diameter with the highest mapped functional values varied depending on the type of functional weighting chosen: kinematic redundancy of fingertip pad positional placement, fingertip pad orientation, or finger force directionality. The group mappings showed that for a cylinder to be grasped in a power grasp by at least 75% of the Healthy or RFA groups, a diameter of 40mm was required. This research utilizes a new hand model to objectively compare design parameters across three different kinematic factors of hand function and across groups with different functional abilities. The ability to conduct these comparisons enables the creation of designs that are universal to all - including accommodation of individuals with limits in their functional abilities.

show abstract

Section: Introductionmentioning

confidence: 99%

Mapping kinematic functional abilities of the hand to three dimensional shapes for inclusive design

Leitkam

Bix

Fuente

et al. 2015

Journal of Biomechanics

View full text Add to dashboard Cite

show abstract

Determining Functional Finger Capabilities of Healthy Adults: Comparing Experimental Data to a Biomechanical Model

Leitkam

Bush

Bix

2014

Journal of Biomechanical Engineering

View full text Add to dashboard Cite

The human hand has a wide range of possible functional abilities that can change with age, disease, and injury, and can vary from individual to individual and subsequently can affect a person's quality of life. The objective of this work was to develop a theoretical model of the space that is reachable by the hand, weighted to represent three types of functionality, and to compare this model to an experimental data set obtained from a healthy hand population. A theoretical model, termed the Weighted Fingertip Space, was developed using 50th percentile published hand data and ranges of finger motion. The functional abilities calculated in the model were the abilities to position the fingertip pad, orient the fingertip pad, and apply directional forces through the fingertip pad at all the reachable points in space with respect to the palm. Following the development of this theoretical model, experimental data sets from nine individuals with healthy hands were obtained through motion capture techniques. The experimental data were then compared to the theoretical model. Comparisons between a 50th percentile theoretical model and a subject with a similar sized hand showed good agreement in weighting parameters and overall size and shape of the model spaces. The experimental data set from the entire sample, which ranged from the 2nd to 95th percentile hand sizes, showed resultant models that, on average, reached smaller volumes of space, but yielded higher values of the functional measures within those volumes. Additionally, in comparison to the theoretical model, the variability of the experimental models showed that small changes in hand dimensions and ranges of motion of the finger joints had a large influence in the functional measures of the model. Combined, these results suggest that the modeling technique can calculate functional ability of the hand, but should be used on an individualized basis for evaluating changes in function (e.g., rehabilitation). Further, scaling to hand size has the potential to yield "average" models for larger population samples.

show abstract

Finger reach envelope using the marching cubes method

Cited by 2 publications

References 20 publications

Mapping kinematic functional abilities of the hand to three dimensional shapes for inclusive design

Mapping kinematic functional abilities of the hand to three dimensional shapes for inclusive design

Determining Functional Finger Capabilities of Healthy Adults: Comparing Experimental Data to a Biomechanical Model

Contact Info

Product

Resources

About