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Xiao Z, Yang C, Li Y, Xing Y, Ma C, Zhang Y, Long X, Li J, Liu C. Human Eye Activity Monitoring Using Continuous Wave Doppler Radar: A Feasibility Study. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2024; 18:322-333. [PMID: 37851555 DOI: 10.1109/tbcas.2023.3325547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Human eye activity has been widely studied in many fields such as psychology, neuroscience, medicine, and human-computer interaction engineering. In previous studies, monitoring of human eye activity mainly depends on electrooculogram (EOG) that requires a contact sensor. This article proposes a novel eye movement monitoring method called continuous wave doppler oculogram (cDOG). Unlike the conventional EOG-based eye movement monitoring methods, cDOG based on continuous wave doppler radar sensor (cDRS) can remotely measure human eye activity without placing electrodes on the head. To verify the feasibility of using cDOG for eye movement monitoring, we first theoretically analyzed the association between the radar signal and the corresponding eye movements measured with EOG. Afterward, we conducted an experiment to compare EOG and cDOG measurements under the conditions of eyes closure and opening. In addition, different eye movement states were considered, including right-left saccade, up-down saccade, eye-blink, and fixation. Several representative time domain and frequency domain features obtained from cDOG and from EOG were compared in these states, allowing us to demonstrate the feasibility of using cDOG for monitoring eye movements. The experimental results show that there is a correlation between cDOG and EOG in the time and frequency domain features, the average time error of single eye movement is less than 280.5 ms, and the accuracy of cDOG in eye movement detection is higher than 92.35%, when the distance between the cDRS and the face is 10 cm and eyes is facing the radar directly.
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Terao Y, Fukuda H, Sugiyama Y, Inomata-Terada S, Tokushige SI, Hamada M, Ugawa Y. Recording Horizontal Saccade Performances Accurately in Neurological Patients Using Electro-oculogram. J Vis Exp 2018. [PMID: 29608147 DOI: 10.3791/56934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Electro-oculogram (EOG) has been widely used for clinical eye movement recording, especially horizontal saccades, although the video-oculography (VOG) has largely taken the place of it nowadays due to its higher spatial accuracy. However, there are situations in which EOG has clear advantages over VOG, e.g., subjects with narrow eye clefts or having cataract lenses, and patients with movement disorders. The present article shows that if properly implemented, EOG can achieve an accuracy almost as good as VOG with substantial stability for recording, while circumventing problems associated with VOG recording. The present paper describes a practical method for recording horizontal saccades using oculomotor paradigms with high accuracy and stability by EOG in neurological patients. The necessary measures are to use an Ag-AgCl electrode with a wide plastic fringe capable of reducing noise, and to wait for sufficient light adaptation to occur. This waiting period also helps to lower the impedance between the electrodes and the skin, thereby ensuring stable signal recorded as time goes by. Furthermore, re-calibration is performed as needed during the task performance. Using this method, the experimenter can avoid drifts of signals, as well as contamination of artifacts or noise from the electromyogram and electroencephalogram, and can collect sufficient data for clinical evaluation of saccades. Thus when implemented, EOG can still be a method of high practicability that can be widely applied to neurological patients, but may be effective also for studies in normal subjects.
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Affiliation(s)
- Yasuo Terao
- Department of Cell Physiology, Kyorin University;
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Bremova-Ertl T, Schiffmann R, Patterson MC, Belmatoug N, Billette de Villemeur T, Bardins S, Frenzel C, Malinová V, Naumann S, Arndt J, Mengel E, Reinke J, Strobl R, Strupp M. Oculomotor and Vestibular Findings in Gaucher Disease Type 3 and Their Correlation with Neurological Findings. Front Neurol 2018; 8:711. [PMID: 29379464 PMCID: PMC5775219 DOI: 10.3389/fneur.2017.00711] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/11/2017] [Indexed: 01/26/2023] Open
Abstract
Objectives To evaluate the function of the oculomotor and vestibular systems and to correlate these findings with the clinical status of patients with Gaucher disease type 3 (GD3). The goal of this cross-sectional and longitudinal study was to find oculomotor biomarkers for future clinical trials. Methods Twenty-six patients with GD3 were assessed for eligibility and 21 were able to perform at least one task. Horizontal and vertical reflexive saccades, smooth pursuit, gaze-holding, optokinetic nystagmus, and horizontal vestibulo-ocular reflex (VOR) were examined by video-oculography/video-head impulse test and compared concurrently with 33 healthy controls. The Scale for the Assessment and Rating of Ataxia (SARA), the modified Severity Scoring Tool (mSST), and Grooved Pegboard Test (GPT) were administered to assess overall neurological function. Eleven patients were also re-assessed after 1 year. Results Nine out of 17 patients exhibited gaze-holding deficits. One patient had upbeat nystagmus. Three patients presented with bilateral abducens palsy in combination with central oculomotor disorders, suggesting a bilateral involvement of the abducens nucleus. Horizontal angular VOR gain was reduced in all patients (0.66 ± 0.37) compared with controls (1.1 ± 0.11, p < 0.001). Most strongly correlated with clinical rating scales were peak velocity of downward saccades (SARA: ρ = −0.752, p < 0.0005; mSST: ρ = −0.611, p = 0.003; GPT: ρ = −0.649, p = 0.005) and duration of vertical saccades (SARA: ρ = 0.806, p < 0.001; mSST: ρ = 0.700, p < 0.0005; GPT: ρ = 0.558, p = 0.02) together with the VOR gain (SARA: ρ = −0.63, p = 0.016; mSST: ρ = −0.725, p = 0.003; GPT: ρ = −0.666, p = 0.004). Vertical smooth pursuit gain decreased significantly at follow-up. Interpretation This study shows neuronal degeneration of the brainstem and cerebellum with combined involvement of both supranuclear and nuclear oculomotor structures and the vestibular system in GD3. We also identified oculomotor parameters that correlate with the neurological status and can be used as biomarkers in future clinical trials.
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Affiliation(s)
- Tatiana Bremova-Ertl
- German Center for Vertigo and Balance Disorders, University Hospital Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians University of Munich, Munich, Germany
| | - Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX, United States
| | - Marc C Patterson
- Department of Neurology, Mayo Clinic Children's Center, Rochester, MN, United States.,Department of Pediatrics, Mayo Clinic Children's Center, Rochester, MN, United States.,Department of Clinical Genomics, Mayo Clinic Children's Center, Rochester, MN, United States
| | - Nadia Belmatoug
- Referral Center for Lysosomal Diseases, Department of Internal Medicine, University Hospital Paris Nord Val-de-Seine, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Thierry Billette de Villemeur
- Sorbonne Universités, UPMC, GRC ConCer-LD and AP-HP, Hôpital Trousseau, Service de Neuropédiatrie - Pathologie du développement, Centre de référence des malformations et maladies congénitales du cervelet, Paris, France
| | - Stanislavs Bardins
- German Center for Vertigo and Balance Disorders, University Hospital Munich, Munich, Germany
| | - Claudia Frenzel
- German Center for Vertigo and Balance Disorders, University Hospital Munich, Munich, Germany.,Department of Neurology, University Hospital Munich, Munich, Germany
| | - Věra Malinová
- First Faculty of Medicine, Department of Pediatrics and Adolescence Medicine, Charles University, General University Hospital Prague, Prague, Czechia
| | - Silvia Naumann
- Villa Metabolica, Center for Paediatric and Adolescent Medicine, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Juliane Arndt
- Villa Metabolica, Center for Paediatric and Adolescent Medicine, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Eugen Mengel
- Villa Metabolica, Center for Paediatric and Adolescent Medicine, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Jörg Reinke
- Villa Metabolica, Center for Paediatric and Adolescent Medicine, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Ralf Strobl
- German Center for Vertigo and Balance Disorders, University Hospital Munich, Munich, Germany.,Institute for Medical Information Processing, Biometrics and Epidemiology, Ludwig-Maximilians University of Munich, Munich, Germany
| | - Michael Strupp
- German Center for Vertigo and Balance Disorders, University Hospital Munich, Munich, Germany.,Department of Neurology, University Hospital Munich, Munich, Germany
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An improved algorithm for automatic detection of saccades in eye movement data and for calculating saccade parameters. Behav Res Methods 2010; 42:701-8. [PMID: 20805592 DOI: 10.3758/brm.42.3.701] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This analysis of time series of eye movements is a saccade-detection algorithm that is based on an earlier algorithm. It achieves substantial improvements by using an adaptive-threshold model instead of fixed thresholds and using the eye-movement acceleration signal. This has four advantages: (1) Adaptive thresholds are calculated automatically from the preceding acceleration data for detecting the beginning of a saccade, and thresholds are modified during the saccade. (2) The monotonicity of the position signal during the saccade, together with the acceleration with respect to the thresholds, is used to reliably determine the end of the saccade. (3) This allows differentiation between saccades following the main-sequence and non-main-sequence saccades. (4) Artifacts of various kinds can be detected and eliminated. The algorithm is demonstrated by applying it to human eye movement data (obtained by EOG) recorded during driving a car. A second demonstration of the algorithm detects microsleep episodes in eye movement data.
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Renner AB, Kellner U, Cropp E, Preising MN, MacDonald IM, van den Hurk JAJM, Cremers FPM, Foerster MH. Choroideremia: variability of clinical and electrophysiological characteristics and first report of a negative electroretinogram. Ophthalmology 2006; 113:2066.e1-10. [PMID: 16935340 DOI: 10.1016/j.ophtha.2006.05.045] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Revised: 03/30/2006] [Accepted: 05/26/2006] [Indexed: 10/24/2022] Open
Abstract
PURPOSE To analyze the variability of clinical and electrophysiological characteristics in X-linked choroideremia and provide the first report of a negative electroretinogram in choroideremia. DESIGN Retrospective study. PARTICIPANTS The records of 18 male patients with choroideremia and 8 female carriers were evaluated. METHODS The data were reviewed regarding visual acuity (VA), color vision, perimetry, fundus autofluorescence, and full-field electroretinography (according to standards of the International Society for Clinical Electrophysiology of Vision). MAIN OUTCOME MEASURES Morphological and functional phenotype characteristics, fundus autofluorescence, electroretinography, and Rab escort protein 1 (REP-1) mutations. RESULTS Four unrelated families with choroideremia (9 affected males, 7 carriers) and 10 unrelated individuals (9 affected males, 1 carrier) were included. Mutational analysis, performed in 2 families and 3 individual males, revealed REP-1 mutations in all except 1 male. The age of the males ranged from 5.9 to 63.0 years (mean, 33.9), and VA ranged from hand movements to 1.0 (median, 0.7). Fundus autofluorescence (n = 7) showed defects in the retinal pigment epithelium in all males. Electroretinography (n = 13) was almost undetectable in 6 males and reduced in 6, indicating a rod-cone dystrophy. A further male showed a negative electroretinogram, with a b:a wave ratio of 0.5. Visual acuity of the 8 carriers (age, 4.8-56.8 years [mean, 24.0]) ranged from light perception to 1.2 (median, 1.0). Light perception was present in 1 carrier manifesting choroideremia with distinct chorioretinal atrophy. Pigmentary stippling, seen in the other carriers, was seen in fundus autofluorescence (n = 1) with a distinct speckled pattern. Electroretinograms were normal in 6 of 7 and reduced in the manifesting carrier. Defects in color vision and visual field were found in affected males and in the female carriers. CONCLUSIONS The phenotype of choroideremia presents with high variability. In addition to the previously reported findings, we observed a negative electroretinogram, indicating a postreceptoral retinal dysfunction, in 1 affected male; severe course of choroideremia with early blindness in 1 manifesting carrier; color vision deficits in the majority of affected males and carriers; and characteristic alterations in fundus autofluorescence.
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Affiliation(s)
- Agnes B Renner
- Department of Ophthalmology, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
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