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385
THREE DIMENSIONAL ANALYSIS OF LIP MOVEMENT BY 3-D AUTO TRACKING SYSTEM
S. MINAKUCHI, Y. HIRANO, T. SEKITA, T. SUZUKI, K. KOBAYASHI and M. NAGAO
Department of Geriatric Dentistry, Faculty of Dentistry, Tokyo Medical & Dental University
1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan, 113
Tel:81-3-3813-6111(ext.5248) Fax : 81-3-5689-6429
KEY WORDS : lip movement, video tracker, auto tracking
ABSTRACT :
Lips and cheeks have great influences on the masticatory and phonetic functions. However, so far, there was few method to
evaluate the lip movements. In this respect, we established a real time measuring system for three-dimensional movements of lips
and cheeks. This system consists of two video trackers placed stereographically and a computer. Additionally, one video tracker
was connected for the measurement of mandibular movements. The-accuracy of this system was evaluated using computerized
XYZ pulse stage. The resolution of this system was 0.10 X0.10X0.10 -mm, when the measurement was carried out in the area of
24.0(X) X 20.0(Y) X 20.0(Z)mm with the working distance of 500 mm and with the frequency of 120 Hz. The lip movements of the
dentulous subjects with the mandibular movements during mastication of 8 types of test foods were analyzed using this system.
1. INTRODUCTION
Movements of lips and cheeks have great influences on the masticatory and phonetic functions. These movements can indicate
the state of harmony between a denture and the soft tissues surrounding the oral cavity. However, so far, there was few method to
evaluate the lip movements. In this respect, we established a real time measuring system for three-dimensional movements of lips
and cheeks. The purpose of this study was to evaluate the accuracy of this system and to analyze the lip movements of the
dentulous subjects with the mandibular movements during mastication.
2. 3-D AUTO TRACKING SYSTEM
2.1 System organization (Fig.1)
This system (3-D Auto Tracking System) consists of two video PC9801
trackers with 75mm ITV lens and 5mm extension ring
(ARTIST G140, OKK Inc., Tokyo, Japan), scan converter G-
SCI-120/60 (OKK Inc.), To monitor (VM-900, Hitachi RS232C I-SIF RS232C I-SIF
Denshi Ltd.), RS 422/RS232C interface board ( RS 422-SIF, ARTISTT ARD BOARD
L.S.I. Japan Ltd.) and personal computer (PC-9801 RA 5, G120
NEC). Two video trackers were placed stereographically for
three dimensional measurement of the lip movement. These Nikon F3
trackers followed the right corner of the subject’s mouth with
the intersection angle of about 60 degrees. Additionally, «o
another video tracker (ARTIST G120) was placed in front of © C
the subjects for two dimensional measurement of mandibular
movements. In order to set up the standard axis on the
subject's head, two 35mm SLD cameras (NIKKON F-3) were
placed with the base distance of about 73 cm.
ARTIST
G140
2.2 Video tracker Standard points
Video tracker (ARTIST G140) is the intelligent image sensing
device using a specially developed solid-state image pick-up
element, which locates two independently moving objects in
real-time while simultaneously tracking them. The
brockdiagram of ARTIST G140 shows in F ig.2 and the )
specifications and functions are as follows: Fig.1 System organization
Head Fixture
IAPRS, Vol. 30, Part 5W1, ISPRS Intercommission Workshop "From Pixels to Sequences", Zurich, March 22-24 1995
