Detection Threshold and Mechanical Impedance of the Hand in a Pen-Hold Posture

We report position and force detection thresholds for sinusoidal waveforms in the frequency range 10-500 Hz delivered through a stylus. The participants were required to hold the stylus in a way similar to that of holding the stylus of a force-feedback device. A minishaker moved the stylus along its length so that the majority of vibrations were presented tangentially to the skin of the hand. The measured position thresholds decreased initially with an increasing stimulus frequency and formed a U-shaped curve in the high frequency region. The thresholds of high frequency vibrations were lower than those reported previously for vibrations that were perpendicular to the skin, but were similar to the thresholds reported earlier using vibrations that were tangential to the skin. A similar force threshold curve was obtained using a force sensor attached to one end of the stylus. Mechanical impedance of the skin derived from velocity estimates and force measurements indicated that the skin and tissues in the hand holding the stylus can be modeled with mass-, damper- and spring-like elements. A comparison of the mechanical impedance from the present study with those reported previously showed similar results for vibrations delivered in the tangential and normal directions to the skin

[1]  M. Leek.  Adaptive procedures in psychophysical research , 2001, Perception & psychophysics.

[2]  Hong Z. Tan,et al.  Perceived Instability of Virtual Haptic Texture: III. Effect of Update Rate , 2007, PRESENCE: Teleoperators and Virtual Environments.

[3]  ChoiSeungmoon,et al.  Perceived Instability of Virtual Haptic Texture , 2007 .

[4]  S. Bolanowski,et al.  Four channels mediate the mechanical aspects of touch. , 1988, The Journal of the Acoustical Society of America.

[5]  Hong Z. Tan,et al.  A Two DOF Controller for a Multi-Finger Tactual Display Using a Loop-Shaping Technique , 2004 .

[6]  S S Hsiao,et al.  Detection of vibration transmitted through an object grasped in the hand. , 1999, Journal of neurophysiology.

[7]  T. McGee,et al.  Sensory aids for the hearing impaired , 1985, Proceedings of the IEEE.

[8]  Alex Pentland,et al.  Tactual displays for sensory substitution and wearable computers , 2005, SIGGRAPH Courses.

[9]  Hong Z. Tan,et al.  Toward realistic haptic rendering of surface textures , 2004 .

[10]  R. Lundström.  Local vibrations--mechanical impedance of the human hand's glabrous skin. , 1984, Journal of biomechanics.

[11]  Hong Z. Tan,et al.  Perceived Instability of Virtual Haptic Texture. I. Experimental Studies , 2004, Presence: Teleoperators & Virtual Environments.

[12]  Hong Z. Tan,et al.  Perceived Instability of Virtual Haptic Texture. II. Effect of Collision-Detection Algorithm , 2005, Presence: Teleoperators & Virtual Environments.

[13]  T. J. Moore,et al.  Measurement of Specific Mechanical Impedance of the Skin: Effects of Static Force, Site of Stimulation, Area of Probe, and Presence of a Surround , 1972 .

[14]  I. Summers.  Tactile Aids for the Hearing Impaired , 1992 .

[15]  Mandayam A. Srinivasan,et al.  Tangential versus normal displacements of skin: relative effectiveness for producing tactile sensations , 2002, Proceedings 10th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. HAPTICS 2002.

[16]  R. Howe,et al.  Identification of the mechanical impedance at the human finger tip. , 1997, Journal of biomechanical engineering.

[17]  H. Levitt.  Transformed up-down methods in psychoacoustics. , 1971, The Journal of the Acoustical Society of America.

[18]  Shuo Yang,et al.  Detection of Torque Vibrations Transmitted Through a Passively-Held Rotary Switch , 2004 .

[19]  Charles Baur,et al.  Delta Haptic Device as a nanomanipulator , 2001, Optics East.

[20]  C. L. Doren.  The effects of a surround on vibrotactile thresholds: Evidence for spatial and temporal independence in the non-Pacinian I (NP I) channel , 1990 .

[21]  Thomas H. Massie,et al.  The PHANToM Haptic Interface: A Device for Probing Virtual Objects , 1994 .

[22]  J. Wu,et al.  Biodynamic response of human fingers in a power grip subjected to a random vibration. , 2004, Journal of biomechanical engineering.

[23]  Domenico Prattichizzo,et al.  Is haptic watermarking worth it? , 2006, Electronic Imaging.