THE COMMON PATTERNS OF BLOOD PERFUSION IN THE FINGERNAIL BED SUBJECT TO FINGERTIP TOUCH FORCE AND FINGER POSTURE

When the human fingertip is pressed against a surface or bent, the hemodynamic state of the fingertip is altered in a way that is common to all people. Normal force, shear force, and finger extension/flexion all result in visibly distinct patterns of blood volume or perfusion beneath the fingernail. These patterns of blood perfusion can be used not only to monitor the state of the finger, but also to understand how the fingernail interacts with the bone and surrounding tissues when various forces or postures are applied. In this paper, photographic techniques are used to catalog the average patterns of fingernail coloration corresponding to various states of applied forces and postures across human subjects of a variety of size, gender, and skin color. Results indicate that there are at least seven different states of force and posture that yield distinct coloration patterns that are statistically significant and common to people in general.

[1]  Thomas H. Wonnacott,et al.  Introductory Statistics , 2007, Technometrics.

[2]  John G. Webster,et al.  Tactile Sensors for Robotics and Medicine , 1988 .

[3]  H. Brown.  NAILS: THERAPY, DIAGNOSIS, SURGERY , 1991 .

[4]  Mandayam A. Srinivasan,et al.  Human fingerpad under indentation I: static and dynamic force response , 1995 .

[5]  Sadao Kawamura,et al.  Analysis of friction on human fingers and design of artificial fingers , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[6]  C. D. Mote,et al.  Force response of the fingertip pulp to repeated compression--effects of loading rate, loading angle and anthropometry. , 1997, Journal of biomechanics.

[7]  R S Fearing,et al.  Tactile After-Images From Static Contact , 1998, Dynamic Systems and Control.

[8]  R. Howe,et al.  Dynamic lumped element response of the human fingerpad. , 1999, Journal of biomechanical engineering.

[9]  R. Howe,et al.  Dynamic contact of the human fingerpad against a flat surface. , 1999, Journal of biomechanical engineering.

[10]  H. Asada,et al.  Photoplethysmograph fingernail sensors for measuring finger forces without haptic obstruction , 2001, IEEE Trans. Robotics Autom..

[11]  H. Harry Asada,et al.  Understanding of fingernail-bone interaction and fingertip hemodynamics for fingernail sensor design , 2002, Proceedings 10th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. HAPTICS 2002.

[12]  H. Harry Asada,et al.  Measurement of finger posture and three-axis fingertip touch force using fingernail sensors , 2004, IEEE Transactions on Robotics and Automation.

[13]  Thenkurussi Kesavadas,et al.  Measuring Fingertip Forces by Imaging the Fingernail , 2006, 2006 14th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems.

[14]  Yu Sun,et al.  Dynamic features and prediction model for imaging the fingernail to measure fingertip forces , 2006, Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006..