DE-AFO: A Robotic Ankle Foot Orthosis for Children with Cerebral Palsy Powered by Dielectric Elastomer Artificial Muscle

Conventional passive ankle foot orthoses (AFOs) have not seen substantial advances or functional improvements for decades, failing to meet the demands of many stakeholders, especially the pediatric population with neurological disorders. Our objective is to develop the first comfortable and unobtrusive powered AFO for children with cerebral palsy (CP), the DE-AFO. CP is the most diagnosed neuromotor disorder in the pediatric population. The standard of care for ankle control dysfunction associated with CP, however, is an unmechanized, bulky, and uncomfortable L-shaped conventional AFO. These passive orthoses constrain the ankle's motion and often cause muscle disuse atrophy, skin damage, and adverse neural adaptations. While powered orthoses could enhance natural ankle motion, their reliance on bulky, noisy, and rigid actuators like DC motors limits their acceptability. Our innovation, the DE-AFO, emerged from insights gathered during customer discovery interviews with 185 stakeholders within the AFO ecosystem as part of the NSF I-Corps program. The DE-AFO is a biomimetic robot that employs artificial muscles made from an electro-active polymer called dielectric elastomers (DEs) to assist ankle movements in the sagittal planes. It incorporates a gait phase detection controller to synchronize the artificial muscles with natural gait cycles, mimicking the function of natural ankle muscles. This device is the first of its kind to utilize lightweight, compact, soft, and silent artificial muscles that contract longitudinally, addressing traditional actuated AFOs' limitations by enhancing the orthosis's natural feel, comfort, and acceptability. In this paper, we outline our design approach and describe the three main components of the DE-AFO: the artificial muscle technology, the finite state machine (the gait phase detection system), and its mechanical structure. To verify the feasibility of our design, we theoretically calculated if DE-AFO can provide the necessary ankle moment assistance for children with CP-aligning with moments observed in typically developing children. To this end, we calculated the ankle moment deficit in a child with CP when compared with the normative moment of seven typically developing children. Our results demonstrated that the DE-AFO can provide meaningful ankle moment assistance, providing up to 69% and 100% of the required assistive force during the pre-swing phase and swing period of gait, respectively.

Footwear-to-feet examination and analysis: Comparing worn footwear to persons and human remains

Footwear-to-feet examination and analysis refers to the process of examining and analyzing footwear in regard to criminal matters. This examination and analysis has been done to include or exclude an individual as the wearer of the footwear in question and to help associate or disassociate human remains to footwear. This review of the subject describes its investigative applications, the research that underpins the process, and considers its legal admissibility. The process of footwear-to-feet examination and analysis is scientifically valid and has been widely accepted. As a result, law enforcement and forensic scientists should be aware of the use of this process to assist in criminal investigations.

Plantar pressure during gait: norm-referenced measurement for Brazilian healthy adults using the Footwork Pro® System

Abstract Introduction The measurement of plantar pressure is an important component in the evaluation of the locomotive system. However, the absence of norm-referenced measurement poses limitations to its use. Objective To verify the influence of gender on plantar pressure during gait in healthy adults and to propose norm-referenced measurement that may be used as a reference for monitoring. Methods The study included 353 healthy participants (158 females and 195 males), aged between 20 and 64 years, and with a normal foot posture. Using a pressure platform, the peak plantar pressure and pressure-time integrals were measured in three areas of the foot: forefoot, midfoot, and hindfoot. Results Both indicators of plantar pressure showed no significant differences between genders (p ≤ 0.05). Higher peak plantar pressure was found in the forefoot region, while a higher pressure-time integral was found in the hindfoot region. Percentile distribution values were made available for the data set of females and males. Conclusion The available norm-referenced measurement may be used to identify pathological gait parameters, monitor the efficacy of therapeutic interventions, and detect individuals in need of referral for a more sophisticated and detailed evaluation.

Single sensor measurement of heel-height during the push-off phase of gait

Objective. In healthy gait a forceful push-off is needed to get an efficient leg swing and propulsion, and a high heel lift makes a forceful push-off possible. The power of the push-off is decreased with increased age and in persons with impaired balance and gait. The aim of this study was to evaluate whether a wearable equipment (Striton) and algorithms to estimate vertical heel-height during gait from a single optical distance sensor is reliable and feasible for clinical applications.Approach. To assess heel-height with the Striton system an optical distance sensor was used to measure the distance to the floor along the shank. An algorithm was created to transform this measure to a vertical distance. The heel-height was validated in an experimental setup, against a 3D motion capture system (MCS), and test-retest and day-to-day tests were performed on 10 elderly persons. As a reference material 83 elderly persons were included, and heel-height was measured before and after surgery in four patients with the neurological disorder idiopathic normal pressure hydrocephalus (iNPH).Main results. In the experimental setup the accuracy was high with a maximum error of 2% at all distances, target colours and inclination angles, and the correlation to the MCS wasR= 0.94. Test-retest and day-to-day tests were equal within ±1.2 cm. Mean heel-height of the elderly persons was 16.5 ± 0.6 cm and in the patients with iNPH heel-height was increased from 11.2 cm at baseline to 15.3 cm after surgery.Significance. Striton can reliably measure heel-height during gait, with low test-retest and day-to-day variability. The system was easy to attach, and simple to use, which makes it suitable for clinical applications.

Hand anthropometry survey in Iranian adults and comparisons with other populations

BACKGROUND

Hand anthropometry is useful for designing manual systems such as hand tools, controls, and gloves. There are limited published data on the hand dimensions of Iranian male and female adults.

OBJECTIVE

This study was undertaken to measure the hand anthropometric dimensions in Iranian adults to compare data between two genders and also with the corresponding data from other nationalities.

METHODS

A total of 34 dimensions of the right hand were measured in 217 male and 128 female adults using a digital caliper and tape. The mean, standard deviation, and the main percentiles are summarized in a table and the mean of each dimension is compared by independent t-tests between genders. Hand dimensions are compared between Iranian and other nationalities such as North Colombian, Korean, Turkish, Nigerian, Bangladeshi, Jordanian, and Vietnamese using the published data.

RESULTS

Females had significantly smaller hand dimensions than males in all dimensions ranged from 4.21%to 18.16%, with the largest differences in hand breadths. Compared with other nationalities, the Iranian male and female adults had wider (greater breadth and circumferences) hands with shorter fingers.

CONCLUSIONS

The results showed significant differences of hand anthropometry between Iranian and other nationalities which should be included in the design and selection of hand tools for Iranian population.

Screening for laterally deviated plantar pressure during stance using the Cumberland ankle instability tool and anthropometric measures

This study developed a method that predicts laterally deviated plantar pressure during stance by lower limb anthropometrics and self-reported ability to stop an ankle which has started to roll over. Thirty-two males ran on a treadmill for 2 minutes at 11 km/h. Foot pressure data were collected by a pressure insole system for classifying the participants as medial or lateral strikers. Cumberland Ankle Instability Tool score, Tegner Activity Scale score, foot arch height, active and passive ankle and knee range of motion, bi-malleolar width, foot length, foot width and calf circumference were measured. Binary logistic regressions were performed to produce a model which estimated if an individual showed laterally deviated foot pressure during stance. The model utilized the score of Cumberland Ankle Instability Tool Question 8, active and passive knee joint external rotation, height, body mass and bimalleolar width (explained variance of 47.3%, p = 0.037), producing a sensitivity of 71.4% and a specificity of 54.5%. A validation trial on another 15 runners reported a 73.3% accuracy in prediction if they are medial or lateral strikes.