Development of a Human Assistive Robot to Support Hip Joint Movement During Sit-to-stand Using Non-linear Springs

In Russia, coxitis is one of the most common extra-axial manifestations of ankylosing spondylitis (AS). However, many issues regarding its early diagnosis remain unresolved.Objective: to compare the clinical manifestations of coxitis with the data from an instrumental examination of CoRSAR cohort (Cohort of Early Axial Spondyloarthritis) patients.Patients and methods. Examinations were made in 175 patients (mean age, 28.2±5.7 years) diagnosed as having axial spondyloarthritis (axSpA) with inflammatory back pain lasting up to 5 years, which occurred at the age of ≤45 years. There was non-radiographic axSpA (nraxSpA) in 69 patients and AS in 106 patients. 87% of patients were HLA-B27-positive. The median disease duration was 23.8 [1–60] months; BASDAI was 3.3±1.94. Regardless of complaints, all the patients underwent hip X-ray and ultrasound studies and 54 more patients had magnetic resonance imaging (MRI).Results and discussion. The clinical signs of coxitis were present in 95 (54%) patients, of them 60% were diagnosed with AS and 40% had nraxSpA. According to the numerical pain rating scale (NPRS), the median hip joint pain was 4 [3; 7]. Limited joint movement was observed in 6 (3.4%) patients. The level of hip joint pain correlated with BASDAI (r=0.53) and ASDAS (r=0.30). The ultrasound signs of coxitis were detected in 42 (24%) patients; of them 26 (62%) had the clinical manifestations of hip joint injury, and such changes were absent in 16 patients. The patients with ultrasound signs of coxitis were noted to have a higher disease activity; peripheral arthritis and enthesitis were more common. According to MRI, coxitis was diagnosed in 39 (72%) of the 54 examinees, while the disease was asymptomatic in 10%.Conclusion. Different diagnostic methods used in patients with early axSpA could reveal coxitis in 33% of cases. The patients with coxitis show higher laboratory disease activity than those without hip joint injury. It is necessary to include MRI and ultrasound in the mandatory examination of patients with axSpA.

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A User-Driven Design Framework for Coupled-Serial-Chain Mechanism Synthesis for Assisting Sit-to-Stand Motion

Journal of Engineering and Science in Medical Diagnostics and Therapy ◽

10.1115/1.4046322 ◽

2020 ◽

Vol 3 (2) ◽

Author(s):

Liuxian Zhu ◽

Hao Lv ◽

Li Li ◽

Xiaofei Xu

Keyword(s):

Rehabilitation Robot ◽

Design Framework ◽

Chain Mechanism ◽

Mechanism Synthesis ◽

Sit To Stand ◽

Serial Chain ◽

Assistive Robot ◽

Physical Prototype ◽

Natural Movement ◽

Human Joints

Abstract This paper presents a novel coupled-serial-chain (CSC) mechanism based multifunctional rehabilitation robot to assist the patients with lower-limb disability in their sit-to-stand (STS) movement. The CSC mechanism is constructed by coupling the joint rotations of a multilink serial chain with gears and operates by following the natural movement of human joints and limbs during the STS motion. The goal is to design an ergonomic and lightweight assistive robot with CSC mechanism that helps minimize the patient's joint/muscle strength and requires the least number of external actuators. A user-driven design framework is proposed to synthesize the CSC mechanism with type and dimensions personalized to the hip trajectory of an individual user. An example CSC mechanism is generated and verified by virtual prototyping and simulation. A physical prototype of the mechanism is built, which will be tested on the human subject to evaluate its maneuverability and physical compatibility with the subject's STS movement.

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Conjugate momentum estimate using non-linear dynamic model of the sit-to-stand correlates well with accelerometric surface data

Journal of Biomechanics ◽

10.1016/j.jbiomech.2011.01.037 ◽

2011 ◽

Vol 44 (6) ◽

pp. 1073-1077 ◽

Cited By ~ 7

Author(s):

Rachid Aissaoui ◽

Raluca Ganea ◽

Kamiar Aminian

Keyword(s):

Dynamic Model ◽

Linear Dynamic ◽

Conjugate Momentum ◽

Sit To Stand ◽

Surface Data ◽

Non Linear

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Comparative Kinematic and Electromyographic Assessment of Clinician- and Device-Assisted Sit-to-Stand Transfers in Patients With Stroke

Physical Therapy ◽

10.2522/ptj.20120500 ◽

2013 ◽

Vol 93 (10) ◽

pp. 1331-1341 ◽

Cited By ~ 20

Author(s):

Judith M. Burnfield ◽

Bernadette McCrory ◽

Yu Shu ◽

Thad W. Buster ◽

Adam P. Taylor ◽

...

Keyword(s):

Repeated Measures ◽

Muscle Activation ◽

Joint Movement ◽

Trunk Flexion ◽

Cross Sectional ◽

Ankle Motion ◽

Repeated Measures Design ◽

Sit To Stand ◽

Lower Extremity Muscle ◽

Combat Injuries

Background Workplace injuries from patient handling are prevalent. With the adoption of no-lift policies, sit-to-stand transfer devices have emerged as one tool to combat injuries. However, the therapeutic value associated with sit-to-stand transfers with the use of an assistive apparatus cannot be determined due to a lack of evidence-based data. Objective The aim of this study was to compare clinician-assisted, device-assisted, and the combination of clinician- and device-assisted sit-to-stand transfers in individuals who recently had a stroke. Design This cross-sectional, controlled laboratory study used a repeated-measures design. Methods The duration, joint kinematics, and muscle activity of 4 sit-to-stand transfer conditions were compared for 10 patients with stroke. Each patient performed 4 randomized sit-to-stand transfer conditions: clinician-assisted, device-assisted with no patient effort, device-assisted with the patient’s best effort, and device- and clinician-assisted. Results Device-assisted transfers took nearly twice as long as clinician-assisted transfers. Hip and knee joint movement patterns were similar across all conditions. Forward trunk flexion was lacking and ankle motion was restrained during device-assisted transfers. Encouragement and guidance from the clinician during device-assisted transfers led to increased lower extremity muscle activation levels. Limitations One lifting device and one clinician were evaluated. Clinician effort could not be controlled. Conclusions Lack of forward trunk flexion and restrained ankle movement during device-assisted transfers may dissuade clinicians from selecting this device for use as a dedicated rehabilitation tool. However, with clinician encouragement, muscle activation increased, which suggests that it is possible to safely practice transfers while challenging key leg muscles essential for standing. Future sit-to-stand devices should promote safety for the patient and clinician and encourage a movement pattern that more closely mimics normal sit-to-stand biomechanics.

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Design of wireless device to measure plantar pressure and gait analysis

Journal of Innovations in Engineering Education ◽

10.3126/jiee.v2i1.36669 ◽

2019 ◽

Vol 2 (1) ◽

pp. 174-181

Author(s):

Mahendra Khatri ◽

Sambardhan Dabadi ◽

Sandeep Kumar Shrestha ◽

Saugat Acharya ◽

Sudip Tamang ◽

...

Keyword(s):

Hip Joint ◽

Lower Limb ◽

Plantar Pressure ◽

Walking Speed ◽

Pressure Sensors ◽

The Body ◽

Joint Movement ◽

Significant Difference ◽

Mean Pressure ◽

The Mean

Foot plantar pressure is the pressure field that acts between the plantar region of the foot and supporting ground. The pressure exerted on the variable region of the foot can be determined using discrete pressure sensors. Information obtained from these sensors is useful in the measurement of gait and posture for diagnosing various problems associated with a lower limb, footwear design, and sports biomechanics. This project is aimed to design a portable in-shoe plantar pressure and gyroscope-based gait angle measurement system. Six Force Sensitive Resistor (FSR) placed in the sole (hallux, 1st, 5th metatarsal, midfoot lateral, midfoot medial and heel respectively) detects the plantar pressure and gyroscope placed at the ankle, knee and hip help measure the orientation and angle of joint movement during various phases of gait. The study among 16 male and 16 female subjects illustrated the significant pressure variation (p<0.0001, t=5.17 with α=95%). Similarly, there was a significant difference in pressure between normal and fast walking speed (p<0.0001, t=5.88) with mean values of 353Kpa and 426Kpa respectively. The mean pressure value for slow walking speed was 423Kpa while there was no significant variation between slow and normal walking speeds (p=0.62, t=1.98). Plantar pressure increased linearly with an increase in the body weight of a person as well. The mean pressure for the 45-50 age group was 313.25Kpa and that for 70-75 was 449Kpa. The study among 10 diabetics and 10 non-diabetic subjects illustrated significantly higher pressure on 1st and 5th metatarsal on diabetic subjects (p=0.0207 and t=2.536). The movement of ankle, knee and hip joint is visualized using the 3D model of a lower limb through processing software. The study illustrated the range of ankle joint movement between -60(dorsiflexion) to 200(plantarflexion), for knee joint was 00 to 300 (flexion) and that for hip joint was -50(extension) to 400(flexion). There was a significant difference in angular values for all three joints while climbing up and down the staircase as compared to walk in a level surface.

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