February 28, 2005
Project: The Slouch-Aware Chair
The Slouch-Aware Chair monitors its sitter's posture to detect unhealthy back positions and provides subtle visual and tactile feedback to encourage good postural habits. The chair senses orientation of the sitter's back through infrared distance rangers. A physical dial placed on the sitter's desk in the peripheral field of view indicates the current posture state - a green region in the 12 o'clock position indicates a healthy posture, while the two red regions off to the sides correspond to two common types of bad posture - backward slouching and forward slumping. If the sitter's bad posture continues over a prolonged period of time, the chair will notify the sitter via intermittent vibration. Vibration will cease when the sitter corrects her posture. The chair features instruction built into the armrest.
The Slouch-Aware chair was designed as a project on nearly invisible computing for CS247a, the Human Computer Interaction Design Studio class at Stanford together with Leor Vartikovski. Inspiration was taken from the Stanford posture class taught by Shawn McCracken.
List of Parts:
1 Ikea JULES desk chair (www.ikea.com, $40-50)
1 Phidgets InterfaceKit 8/8/8 (www.phidgets.com)
1 Phidgets Servo
2 AA Batteries w/ battery holder
2 Sharp GP2D120 IR distance rangers (www.acroname.com)
1 vibrating 3V DC motor (www.allelectronics.com)
1 4N4001 diode
1 D44H11 power transistor
1 generic switch
1 small solderless breadboard
2 custom sheet metal brackets (PRL)
tape, 1/4" foam core, wire
Technical details: coming soon...
Phidgets InterfaceKit, batteries for powering the motor, and protoboard to hold the simple circuit are all hidden in the armrest.
The 'Slouch-O-Meter' desktop display box.
Sensor and motor assembly on the back of the chair - sensors mounted with custom bent sheet metal brackets to guarantee minimum sensor distance of 1.5 inches to closest object.
Sensor and motor assembly on the back of the chair seen from above.
Flip-open instructions in the armrest.
In-class demonstration.