memo of finger sensor technology

1. Survey of finger gesture
sensing
(working memo)
Yoshiharu Sato

2. Scopes
• Not
• 3D gesture in air
• But
• Gesture on a surface (palm, desk, etc)
• Simple gestures

3. Optical approach
• Infrared Camera (Depth of Field)
• Leap Motion, MSR, HP
• Advantages
• Remote sense (no obstacle on fingers)
• Technology is matured, Already in commercial product
• Disadvantages
• Problem of occlusion
• Need an artifact in environment (eg desktop)
• Finger nail sensor
• “Photoplethysmograph Fingernail Sensors for Measuring Finger Forces
Without Haptic Obstruction”, MIT, 2001.
• The force on finger is detected by an optical sensor mounted on the fingernail.
• Advantages
• Can capture finger tactile information (pressure)
• Disadvantages
• Artifact on nail

4. Acoustic approach
• “The Sound of One Hand: A Wrist-mounted Bio-acoustic
Fingertip Gesture Interface”, ATT, CHI2002
• It uses piezo microphone in wrist band. It can classify tap/rub/flick
gestures and distinguish them from everyday life motions.
• “Skinput: Appropriating the Body as an Input Surface”, MSR,
2010
• It uses a custom piezo film array sensor in arm band. It can classify
position on one hand by the other hand’s tap. It can classify which
finger tap is made against a thump finger.
• Advantages
• Remote sense (no obstacle on fingers)
• Can classify simple gestures and their position on body wide surface
• Disadvantages
• ?

5. Accelerometer approach
• “Body Coupled FingeRing: Wireless Wearable Keyboard", CHI 97
• Sensors are attached at fingers, output is converted to a frequency spectrum which is
filtered by a band-pass.
• “Finger Ring Device for Tactile Sensing and Human Machine Interface” (2007),
“Finger Ring Tactile Interface Based on Propagating Elastic Waves on Human
Fingers”, U-Tokyo
• A sensor is attached at its finger base. It can classify movement and tap of fingertip. It can
estimate a finger movement distance on a hard surface.
• https://www.jstshingi.jp/abst/p/11/1151/aizu05.pdf, Aizu Univ.
• Shiseido https://www.shiseidogroup.com/releimg/1959-e.pdf , 2011
• Ring http://logbar.jp/ring/
• Advantages
• Matured technology (though Ring development is in trouble now)
• Can detect simple gestures
• Artifact on finger base is not an obstacle of everyday life.
• Disadvantages
• ?