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Lee S, Jeong J, Kim N, Shin M, Kim S. Improving Performance of the Human Pupil Orbit Model (HPOM) Estimation Method for Eye-Gaze Tracking. SENSORS (BASEL, SWITZERLAND) 2022; 22:9398. [PMID: 36502099 PMCID: PMC9737162 DOI: 10.3390/s22239398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Eye-gaze direction-tracking technology is used in fields such as medicine, education, engineering, and gaming. Stability, accuracy, and precision of eye-gaze direction-tracking are demanded with simultaneous upgrades in response speed. In this study, a method is proposed to improve the speed with decreases in the system load and precision in the human pupil orbit model (HPOM) estimation method. The new method was proposed based on the phenomenon that the minor axis of the elliptical-deformed pupil always pointed toward the rotational center presented in various eye-gaze direction detection studies and HPOM estimation methods. Simulation experimental results confirmed that the speed was improved by at least 74 times by consuming less than 7 ms compared to the HPOM estimation. The accuracy of the eye's ocular rotational center point showed a maximum error of approximately 0.2 pixels on the x-axis and approximately 8 pixels on the y-axis. The precision of the proposed method was 0.0 pixels when the number of estimation samples (ES) was 7 or less, which showed results consistent with those of the HPOM estimation studies. However, the proposed method was judged to work conservatively against the allowable angle error (AAE), considering that the experiment was conducted under the worst conditions and the cost used to estimate the final model. Therefore, the proposed method could estimate HPOM with high accuracy and precision through AAE adjustment according to system performance and the usage environment.
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Affiliation(s)
- Seungbong Lee
- Department of Medical Biotechnology, Dongguk University Biomedi Campus, 32, Dongguk-ro, Ilsan dong-gu, Goyang-si 10326, Republic of Korea
| | - Jaehoon Jeong
- Medical Device Industry Program in Graduate School, Dongguk University, 30, Pildong-ro 1-gill, Jung-gu, Seoul 04620, Republic of Korea
| | - Nahyun Kim
- Department of Medical Biotechnology, Dongguk University Biomedi Campus, 32, Dongguk-ro, Ilsan dong-gu, Goyang-si 10326, Republic of Korea
| | - Manjae Shin
- Department of Medical Biotechnology, Dongguk University Biomedi Campus, 32, Dongguk-ro, Ilsan dong-gu, Goyang-si 10326, Republic of Korea
| | - Sungmin Kim
- Department of Medical Biotechnology, Dongguk University Biomedi Campus, 32, Dongguk-ro, Ilsan dong-gu, Goyang-si 10326, Republic of Korea
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Harada S, Imai T, Takimoto Y, Ohta Y, Sato T, Kamakura T, Takeda N, Kitahara T, Kondo M, Ueno Y, Shimada S, Inohara H. Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex. Sci Rep 2021; 11:17191. [PMID: 34433883 PMCID: PMC8387381 DOI: 10.1038/s41598-021-96596-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
In the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.
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Affiliation(s)
- Shotaro Harada
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takao Imai
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Yasumitsu Takimoto
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yumi Ohta
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takashi Sato
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takefumi Kamakura
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Noriaki Takeda
- Department of Otorhinolaryngology - Head and Neck Surgery, Tokushima University Graduate School of Medicine, Tokushima, Japan
| | - Tadashi Kitahara
- Department of Otorhinolaryngology - Head and Neck Surgery, Nara Medical University, Nara, Japan
| | - Makoto Kondo
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yuya Ueno
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shoichi Shimada
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hidenori Inohara
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Wu X, Yu S, Shen S, Liu W. Quantitative analysis of the biomechanical response of semicircular canals and nystagmus under different head positions. Hear Res 2021; 407:108282. [PMID: 34130038 DOI: 10.1016/j.heares.2021.108282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 01/11/2023]
Abstract
The semicircular canals (SCCs) in the vestibular system can sense angular motion of the head, which performs a crucial role in maintaining the human's sense of balance. The different spatial orientations of the head affect the response of human SCCs to rotational movement. In this study, we combined the numerical model of bilateral human SCCs with vestibulo-ocular reflex experiments, and quantitatively investigated the responses of SCCs to constant angular acceleration when the head was in different left-leaning positions, including the head tilted 0°, 15°, 30°, 45°, 60°, 70°, 80°, and 90° to the left. The results showed that the vertical nystagmus slow-phase velocity (SPV) and the corresponding maximal cupula shear strain at the crista surface rose with an increase in the left-leaning angle of the head, reached a maximum at the position of the head tilted approximately 70° to the left, and then decreased gradually. Both the horizontal nystagmus SPV and the corresponding maximal cupula shear strain at the crista surface were the largest under the position of the head tilted 0° to the left, and decreased gradually as the left-leaning angle of the head increased. The numerical results of cupula shear strain at the crista surface in bilateral SCCs can quantitatively explain the combined effects of each SCC's excitation or inhibition on volunteers' nystagmus SPV under different head positions. In addition, a fluid-structure interaction investigation revealed that different left-leaning head positions changed the endolymphatic pressure gradient distribution in SCCs, which determined the transcupular pressure, cupula shear strain at the crista surface, and nystagmus SPV.
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Affiliation(s)
- Xiang Wu
- School of Information and Communication Engineering, Dalian University of Technology, Dalian 116024, China
| | - Shen Yu
- State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China
| | - Shuang Shen
- School of Rehabilitation Medicine, Binzhou Medical University, Yantai 264003, China
| | - Wenlong Liu
- School of Information and Communication Engineering, Dalian University of Technology, Dalian 116024, China.
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Goyens J. Modelling shows that stimulation of the semicircular canals depends on the rotation centre. Hear Res 2020; 396:108071. [DOI: 10.1016/j.heares.2020.108071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/24/2020] [Accepted: 08/31/2020] [Indexed: 11/15/2022]
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Jiang X, Imai T, Okumura T, Ohta Y, Osaki Y, Sato T, Inohara H. Three-dimensional analysis of the vestibulo-ocular reflex and the ability to distinguish the direction of centripetal acceleration in humans during eccentric rotation with the right ear facing downwards. Neurosci Res 2018; 144:21-29. [PMID: 30217698 DOI: 10.1016/j.neures.2018.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/25/2018] [Accepted: 09/03/2018] [Indexed: 11/24/2022]
Abstract
This study was conducted to evaluate the linear vestibulo-ocular reflex (lVOR) mediated by the saccule, and to investigate the relationship between the lVOR and the ability to distinguish the direction of centripetal acceleration during centric and eccentric rotation. Participants sat on a chair in darkness, with the right ear facing downwards, either directly above the center of rotation, or with their nose out, nose in, right shoulder out, or left shoulder out against the center of rotation (eccentric rotation). Participants were given no information about the chair position, and were rotated sinusoidally at 0.1-0.7 Hz. Three-dimensional eye movements during rotation were analyzed. Participants were asked to describe the position of the chair after rotation. Correctly reporting the five possible chair positions requires recognition of the direction of centripetal acceleration. We analyzed the rate of correct answers to assess participants' ability to identify the direction of centripetal acceleration. lVOR mediated by the saccule was observed only at high rotational frequencies. The rate of correct answers was higher at high rotational frequencies than that at low rotational frequencies. These results indicate that high rotational frequency is important for both lVOR mediated by the saccule and distinguishing the direction of centripetal acceleration.
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Affiliation(s)
- Xiuwen Jiang
- Department of Otorhinolaryngology - Head and Neck Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, 310016, China
| | - Takao Imai
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Tomoko Okumura
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yumi Ohta
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yasuhiro Osaki
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takashi Sato
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hidenori Inohara
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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Imai T, Takimoto Y, Okumura T, Higashi-Shingai K, Takeda N, Kitamura K, Kalubi B, Fujikado T, Hirota M, Midoh Y, Nakamae K, Inohara H. Visual Target Strategies in Infantile Nystagmus Patients With Horizontal Jerk Waveform. Front Neurol 2018; 9:622. [PMID: 30104998 PMCID: PMC6077220 DOI: 10.3389/fneur.2018.00622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/10/2018] [Indexed: 11/24/2022] Open
Abstract
The aim of this study was to propose a new pathophysiological hypothesis for involuntary eye oscillation in infantile nystagmus (IN): patients with IN exhibit impaired gaze fixation, horizontal smooth pursuit and optokinetic nystagmus (OKN) and use saccadic eye movements for these underlying impairments. In order to induce saccades, they make enough angle between gaze and target by precedent exponential slow eye movements. IN consists of the alternate appearance of the saccade and the slow eye movements. Unlike most previous theories, IN is therefore considered a necessary strategy allowing for better vision and not an obstacle to clear vision. In five patients with IN, eye movements were analyzed during the smooth pursuit test, saccadic eye movement test, OKN test and vestibulo-ocular reflex (VOR) test. Their gaze fixation, horizontal smooth pursuit, OKN and the last half of the slow phase of VOR were impaired. The lines obtained by connection of the end eye positions of fast phase of nystagmus coincided with the trajectories of targets. The findings indicate that patients followed the target by the fast but not the slow phase of nystagmus, which supports our hypothesis. By setting the direction of slow phase of nystagmus opposite to the direction of the OKN stimulation, enough angle can be effectively made between the gaze and target for the induction of saccade. This is the mechanism of reversed OKN response. In darkness and when eyes are closed, IN weakens because there is no visual target and neither the saccade for catching up the target or slow phase for induction of the saccade is needed.
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Affiliation(s)
- Takao Imai
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | | | - Tomoko Okumura
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | | | - Noriaki Takeda
- Department of Otorhinolaryngology - Head and Neck Surgery, Tokushima University Graduate School of Medicine, Tokushima, Japan
| | - Koji Kitamura
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Bukasa Kalubi
- Medical Education Center, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takashi Fujikado
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masakazu Hirota
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yoshihiro Midoh
- Department of Information Systems Engineering, Osaka University Graduate School of Information Science and Technology, Osaka, Japan
| | - Koji Nakamae
- Department of Information Systems Engineering, Osaka University Graduate School of Information Science and Technology, Osaka, Japan
| | - Hidenori Inohara
- Department of Otorhinolaryngology - Head and Neck Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
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