Ryo Eguchi
Postdoctoral Scholar, Mechanical Engineering
Contact
https://orcid.org/0000-0003-2420-5847All Publications
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Human Leg Tracking by Fusion of Laser Range and Insole Force Sensing With Gaussian Mixture Model-Based Occlusion Compensation
IEEE SENSORS JOURNAL
2022; 22 (4): 3704-3714
View details for DOI 10.1109/JSEN.2021.3139939
View details for Web of Science ID 000754264700084
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Between-Tactor Display Using Dynamic Tactile Stimuli
SPRINGER INTERNATIONAL PUBLISHING AG. 2022: 379-381
View details for Web of Science ID 000886345900051
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Shift-Adaptive Estimation of Joint Angle Using Instrumented Brace With Two Stretch Sensors Based on Gaussian Mixture Models (vol 5, pg 5881, 2020)
IEEE ROBOTICS AND AUTOMATION LETTERS
2020; 5 (4): 6804
View details for DOI 10.1109/LRA.2020.3019561
View details for Web of Science ID 000568656300001
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Shift-Adaptive Estimation of Joint Angle Using Instrumented Brace With Two Stretch Sensors Based on Gaussian Mixture Models
IEEE ROBOTICS AND AUTOMATION LETTERS
2020; 5 (4): 5881-5888
View details for DOI 10.1109/LRA.2020.3010486
View details for Web of Science ID 000554894900010
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Gait analysis of patients with distal radius fracture by using a novel laser Timed Up-and-Go system
GAIT & POSTURE
2020; 80: 223-227
Abstract
Postmenopausal women are at risk of fall and fracture with the physical decline. Distal radius fracture (DRF) is considered as the primary fragility fracture, and women with this fracture showed poor results in the usual Timed Up-and-Go (TUG) test, indicating a decline in balance and physical ability. The detailed physical characteristics of female DRF patients have not been extensively examined.Is the novel laser TUG system able to detect and analyze the detailed gait characteristics in patients with DRF whose physical ability has tended to decline?In this cross-sectional case control study, the gait characteristics of 32 female patients with DRF who had undergone surgery were evaluated at 2 weeks postoperatively with a laser TUG system to analyze the detailed leg motion during normal TUG test. Forty-three age- and sex-matched non-fractured women were evaluated by the laser TUG system as controls. Lifestyle and present illness were corrected at the time of TUG measurement. Detailed data during laser TUG in both groups were compared statistically, and odds ratio and thread shod of the fracture was elucidated through a logistic regression analysis.DRF patients showed slower speed and had to do more steps to complete the TUG test. Furthermore, asymmetric trajectory and significantly further distance from the marker were observed. Thirteen steps to complete the TUG test was the thread shod of DRF.Detailed gait characteristics of patients with DRF were detected by the laser TUG system. The gait decline and abnormality could be one of the reasons of consecutive fragility fracture. To prevent secondary fragility fractures, this system can be useful for screening.
View details for DOI 10.1016/j.gaitpost.2020.06.005
View details for Web of Science ID 000548455400004
View details for PubMedID 32540778
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Estimation of Vertical Ground Reaction Force Using Low-Cost Insole With Force Plate-Free Learning From Single Leg Stance and Walking
IEEE JOURNAL OF BIOMEDICAL AND HEALTH INFORMATICS
2020; 24 (5): 1276-1283
Abstract
For the evaluation of pathological gait, a machine learning-based estimation of the vertical ground reaction force (vGRF) using a low-cost insole is proposed as an alternative to costly force plates. However, learning a model for estimation still relies on the use of force plates, which is not accessible in small clinics and individuals. Therefore, this paper presents a force plate-free learning from a single leg stance (SLS) and natural walking measured only by the insoles. This method used a linear least squares regression that fits insole measurements during SLS to body weight in order to learn a model to estimate vGRF during walking. Constraints were added to the regression so that vGRF estimates during walking were of proper magnitude, and the constraint bounds were newly defined as a linear function of stance duration. Moreover, a lower bound for the estimated vGRF in mid-stance was added to the constraints to enhance estimation accuracy. The vGRF estimated by the proposed method was compared with force platforms for 4 healthy young adults and 13 elderly adults including patients with mild osteoarthritis, knee pain, and valgus hallux. Through the experiments, the proposed learning method had a normalized root mean squared error under 10% for healthy young and elderly adults with stance durations within a certain range (600-800 ms). From these results, the validity of the proposed learning method was verified for various users requiring assessment in the field of medicine and healthcare.
View details for DOI 10.1109/JBHI.2019.2937279
View details for Web of Science ID 000535614100005
View details for PubMedID 31449034
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Transcutaneous Electrical Nerve Stimulation Improves Stair Climbing Capacity in People with Knee Osteoarthritis
SCIENTIFIC REPORTS
2020; 10 (1): 7294
Abstract
This study aimed to examine the effect of transcutaneous electrical nerve stimulation (TENS) on stair climbing capacity in individuals with pre-radiographic to mild knee osteoarthritis (OA). This is a secondary analysis of data from a single, participant-blinded, randomized controlled trial with a pre-post design. Participants with pre-radiographic to mild knee OA (mean age, 59.1 years; 72.9% women) were randomly assigned into two groups, a TENS (n = 30) and a sham-TENS groups (n = 29). TENS or sham-TENS treatments were applied to all participants by using the prototype TENS device with pre-specified parameters. The primary outcome measures included valid and reliable functional measures for stair climbing (stair-climb test [SCT]), visual analog scale for knee pain during the SCT, and quadriceps muscle strength. TENS improved SCT time by 0.41 s (95% confidence interval [CI]: 0.07, 0.75). The time reduction in the transition phase explains the TENS therapeutic effect. Post-hoc correlation analyses revealed a non-significant but positive relationship between the pain relief effect and improved 11-step SCT time in the TENS group but not in the sham-TENS group. These results indicate that the TENS intervention may be an option for reducing the burden of early-stage knee OA.
View details for DOI 10.1038/s41598-020-64176-0
View details for Web of Science ID 000560744500002
View details for PubMedID 32350320
View details for PubMedCentralID PMC7190707
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Hip abductor muscle weakness and slowed turning motion in people with knee osteoarthritis
JOURNAL OF BIOMECHANICS
2020; 101: 109652
Abstract
Laser range sensor-based timed up and go (laser-TUG) test can evaluate performance in TUG subtasks (sit-to-walk [STW], walking a short distance, and turning). This study aimed to test the hypothesis that weaker hip abductor muscle strength is more significantly associated with slowed turning speed than with the other TUG subtasks (STW and straight walking) after controlling for quadriceps muscle strength in patients with knee osteoarthritis (OA). Community-dwelling participants with knee OA (Kellgren and Lawrence [K&L] grade ≥ 1; mean age, 68.6 years; 70.3% women) underwent laser-TUG. Spatiotemporal gait parameters in TUG and the TUG subtasks were evaluated as outcome measures. The isometric muscle strength of the hip abductor and quadriceps was measured using a hand-held dynamometer. Multiple linear regression analysis was performed to examine the relationship between muscle strength as an independent variable and spatiotemporal parameters as dependent variables. The relative importance of hip abductor muscle strength was determined using the percentages of unique variance. Participants with weaker hip abductor muscle strength demonstrated 0.094 m/s slower turning speed after adjustment for covariates including quadriceps muscle strength. The unique variance explained by hip abductor muscle strength in turning speed was 2.1%. However, no significant relationships were confirmed between weak hip abductor muscle strength and the time to perform TUG and the straight walking (forward and return) phase. These findings indicate that turning motion may be more sensitive to aggravated hip abductor muscle weakness and may show better response to hip muscle strengthening exercises. Longitudinal studies are warranted to elucidate this issue.
View details for DOI 10.1016/j.jbiomech.2020.109652
View details for Web of Science ID 000517653300002
View details for PubMedID 32019677
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Detailed analysis of the transverse arch of hallux valgus feet with and without pain using weightbearing ultrasound imaging and precise force sensors
PLOS ONE
2020; 15 (1): e0226914
Abstract
Hallux valgus is the most common forefoot deformity and affects the transverse arch structure and its force loading patterns. This study aims to clarify the differences in the transverse arch structure and the force under the metatarsal heads individually, between normal feet and hallux valgus feet, and between hallux valgus feet with pain and without pain. We further test the association between the parameters of the transverse arch and hallux valgus angle and between the parameters and pain in hallux valgus.Women's feet (105 feet) were divided into normal group (NORM) and hallux valgus group (HVG); and further into subgroups: hallux valgus without pain (HV Pain (-)) and hallux valgus with pain (HV Pain (+)). Transverse arch height and metatarsal heads height were measured using weight-bearing ultrasound imaging. Force under the metatarsal heads was measured using force sensors attached directly on the skin surface of the metatarsal heads. The measurements were taken in three loading positions: sitting, quiet standing and 90% weight shift on the tested foot. Differences between the groups were compared using Student t-test and Wilcoxon Exact test. Multivariate logistic analysis with adjustment for physical characteristics was also conducted.Transverse arch height was significantly higher in HVG than in NORM in all positions; there were no significant differences between HV Pain (+) and HV pain (-). Lateral sesamoid was significantly higher in HVG and HV Pain (+) than in NORM and HV Pain (-) respectively when bearing 90% of the body weight unilaterally. There was a trend of higher forces under the medial forefoot without significant difference. Transverse arch height and lateral sesamoid height were associated with the hallux valgus angle, while lateral sesamoid height was associated with forefoot pain in hallux valgus deformity.This study shows the differences in the transverse arch structure between normal feet and feet with hallux valgus, and between hallux valgus feet with and without pain. This finding is noteworthy when considering future treatments of painful feet, notably the height of the lateral sesamoid which seems to play a role in forefoot pain.
View details for DOI 10.1371/journal.pone.0226914
View details for Web of Science ID 000534341100010
View details for PubMedID 31917790
View details for PubMedCentralID PMC6952079
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Stair climbing ability in patients with early knee osteoarthritis: Defining the clinical hallmarks of early disease
GAIT & POSTURE
2019; 72: 148-153
Abstract
A growing clinical interest has been shown towards identifying knee osteoarthritis (OA) patients at earlier stages. The early detection of knee OA may allow for more effective interventions.The aim of this study was to determine the discriminative ability of a stair-climb test (SCT) in identifying patients with early knee OA, and to determine if descending stair time during the SCT is better than ascending stair time for the identification of these patients.This study was a secondary, cross-sectional analysis of baseline data from a randomized controlled trial. Adults with moderate to severe knee pain were enrolled (n = 57; mean age 58.9 years; 71.9% women). Each participant performed an 11-step SCT (11-SCT) while wearing shoes with a pressure sensor insole. A receiver operating characteristic analysis was used to examine the discriminative power of 11-SCT for identifying early knee OA (Kellgren and Lawrence grade 1). The discriminative power was also compared between the ascending and descending 11-SCT time as evaluated by the pressure sensor.The 11-SCT time in patients with early knee OA was 0.55 s longer than that in those with symptomatic non-radiographic OA. A one-second increase in the 11-SCT time was significantly associated with 1.9-fold increased odds of early knee OA being present. The 11-SCT value with the best balance of sensitivity and specificity for identifying early knee OA was 8.33 s (area under the curve: 0.711). The descending time was not significantly better than the ascending time for identifying early knee OA.This study determined the time values of an 11-SCT that may be useful for identifying early knee OA patients. These preliminary findings may serve as the foundation for future studies investigating the clinical hallmarks associated with early knee OA.
View details for DOI 10.1016/j.gaitpost.2019.06.004
View details for Web of Science ID 000478682600023
View details for PubMedID 31202024
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Insole-Based Estimation of Vertical Ground Reaction Force Using One-Step Learning With Probabilistic Regression and Data Augmentation
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
2019; 27 (6): 1217-1225
Abstract
An insole-based estimation of the vertical ground reaction force (vGRF) is proposed as an alternative to costly force plates for the evaluation of pathological gait. However, machine learning techniques for estimation still rely on the use of force plates. Moreover, measuring plural walking steps in order to prevent overfitting induces fall risks and physically taxes the patients. Therefore, this paper presents an accessible and efficient learning scheme for the insole-based estimation of vGRF. In this system, we employ a low-cost scale as an alternative to force plates. Then, we use Gaussian process regression (GPR) to learn a model in order to estimate vGRF without overfitting of small-sized data sets corrupted by measurement errors and noise of the devices. In addition, we propose a "one-step learning" scheme based on a probabilistic data augmentation. This approach augments actual measurements of a minimum (just one) walking step to a virtual data set for plural steps by considering their typical variability between steps. In experiments, the GPR models learned from two walking steps estimated vGRF with mean errors of 8% or under for entire/local magnitudes. Moreover, the learning from one step with probabilistic augmentation enhanced the estimation accuracy.
View details for DOI 10.1109/TNSRE.2019.2916476
View details for Web of Science ID 000471121000012
View details for PubMedID 31094691
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Effects of interaction between varus thrust and ambulatory physical activity on knee pain in individuals with knee osteoarthritis: an exploratory study with 12-month follow-up
CLINICAL RHEUMATOLOGY
2019; 38 (6): 1721-1729
Abstract
This study aimed to examine the interaction effect between ambulatory physical activity (PA) and varus thrust on knee pain in individuals with knee osteoarthritis (OA).Subjects (n = 207; mean age: 73.1 years, 71.5% women) in orthopedic clinics with diagnosed knee OA (Kellgren/Lawrence grade ≥ 1) were enrolled in this 12-month observational cohort study. Participants underwent gait observation for varus thrust assessment and pedometer-based ambulatory PA measurements at baseline and 12-month follow-up. Knee pain intensity was assessed using the Japanese Knee Osteoarthritis Measure pain subscale as a primary outcome measure. Multiple linear regression analyses were performed to evaluate ambulatory PA-thrust interaction on knee pain intensity.Ninety-two subjects (mean age, 73.4 years; 68.5% women) completed the 12-month follow-up assessment. Baseline ambulatory PA-thrust interaction was significant (P = 0.017) in the cross-sectional analysis, adjusting for covariates, which yielded R2 = 0.310. Subgroup analysis showed that varus thrust was significantly associated with worse knee pain in subjects walking ≥ 5000 steps/day adjusting for covariates (beta: 7.94; 95% CI: 3.82, 12.1; P < 0.001) with a higher predictive ability (R2 = 0.664). In contrast, ambulatory PA-thrust interaction in the longitudinal analysis showed no significant association with knee pain changes.Ambulatory PA interacted with varus thrust in the association with knee pain, as coexisting high ambulatory PA and varus thrust had the strongest association with higher knee pain. Maximal pain relief effects might be achieved when both ambulatory PA and varus thrust are treated simultaneously, rather than treating each separately.
View details for DOI 10.1007/s10067-019-04472-x
View details for Web of Science ID 000469866000022
View details for PubMedID 30847687
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Concurrent validity and measurement error of stair climb test in people with pre-radiographic to mild knee osteoarthritis
GAIT & POSTURE
2019; 68: 335-339
Abstract
Stair climbing is the task first affected in patients with knee osteoarthritis (OA); therefore, the precise measurement of time required to climb stairs is important to identify mobility limitations, particularly in the early phase of knee OA.This study aimed to examine the test-retest reliability, measurement error, and concurrent validity of the stopwatch-based stair-climb test (SCT) in adults with pre-radiographic to mild knee OA.Fifty-nine participants (mean age, 59.1 [range, 50-69] years; 72.9% female) with Kellgren and Lawrence grade ≤2 disease underwent an 11-step SCT (11-SCT) in accordance with the Osteoarthritis Research Society International recommended method while wearing pressure sensor-mounted standard shoes that is used as a gold standard procedure. Test-retest reliability, measurement errors, and the concurrent validity of the stopwatch-based 11-SCT were evaluated.The test-retest reliability of the stopwatch-based 11-SCT was excellent (intra-class correlation coefficient1,1 [ICC1,1], 0.952; 95% confidence interval [CI], 0.560 to 0.985; p < 0.001) and the minimal detectable change95 was 0.102 s. Concurrent validity was excellent (ICC2,1: 0.957; 95% CI: 0.661 to 0.986; p < 0.001).The stopwatch-based 11-SCT had high test-retest reliability and high concurrent validity, which justify its clinical use for identifying mobility limitations in individuals with pre-radiographic to mild knee OA. A difference of 0.2 s in the stopwatch-based 11-SCT time would be considered a true difference beyond a 95% measurement error.
View details for DOI 10.1016/j.gaitpost.2018.12.014
View details for Web of Science ID 000457971700055
View details for PubMedID 30576977
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Trunk movement asymmetry associated with pain, disability, and quadriceps strength asymmetry in individuals with knee osteoarthritis: a cross-sectional study
OSTEOARTHRITIS AND CARTILAGE
2019; 27 (2): 248-256
Abstract
This study examined 1) the clinical relevance of trunk movement asymmetry, which was evaluated using a trunk-mounted inertial measurement unit (IMU), and 2) the relationship between trunk movement asymmetry and lower limb muscle strength asymmetry in individuals with knee osteoarthritis (OA).One-hundred-thirty-one participants (mean age, 74.2 years; 71.8% female; Kellgren and Lawrence [K&L] grade ≥1) underwent gait analysis at their preferred pace for IMU-based measurement of trunk movement asymmetry (harmonic ratio [HR] and improved HR). The isometric strength of quadriceps and hip abductors was evaluated using a hand-held dynamometer. Pain and disability level were evaluated using a validated self-reported questionnaire. Multiple regression analyses with covariate adjustment were performed to examine the relationship between trunk movement asymmetry (independent variable) and pain, disability level, or muscle strength asymmetry (dependent variables).Individuals with severe knee OA (K&L grade ≥3) had increased trunk movement asymmetry in the medio-lateral axis compared to those with a K&L grade of 1. Increased trunk movement asymmetry was associated with a greater knee pain and disability. The increased trunk movement asymmetry was significantly associated with an increase in the asymmetry of quadriceps strength, but not with asymmetry in the strength of hip abductor.Our findings indicate that increased medio-lateral trunk movement asymmetry may be an indicator of impairment, rather than adaptation, in individuals with knee OA. This preliminary finding warrants validation by future study. Paying close attention to medio-lateral trunk movement asymmetry may be key to our understanding of OA-related pain and disability.
View details for DOI 10.1016/j.joca.2018.10.012
View details for Web of Science ID 000456412900006
View details for PubMedID 30445222
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Spatiotemporal and Kinetic Gait Analysis System Based on Multisensor Fusion of Laser Range Sensor and Instrumented Insoles
IEEE. 2019: 4876-4881
View details for Web of Science ID 000494942303080
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Validity of the Nintendo Wii Balance Board for Kinetic Gait Analysis
APPLIED SCIENCES-BASEL
2018; 8 (2)
View details for DOI 10.3390/app8020285
View details for Web of Science ID 000427510300137
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Accessible Calibration of Insole Force Sensors Using the Wii Balance Board for Kinetic Gait Analysis
IEEE. 2018: 475-478
View details for Web of Science ID 000468199300124
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Accessible Ground Reaction Force Estimation Using Insole Force Sensors without Force Plates
IEEE. 2017: 2861-2865
View details for Web of Science ID 000426957300499
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Kinetic and Spatiotemporal Gait Analysis System Using Instrumented Insoles and Laser Range Sensor
IEEE. 2017: 705-709
View details for Web of Science ID 000427598700123
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Ground Reaction Force Estimation Using Insole Plantar Pressure Measurement System from Single-Leg Standing
IEEE. 2016: 109-113
View details for Web of Science ID 000405714400018