Abstract-Lower extremity amputees suffer from mobility limitations which will result in a degradation of their quality of life. Wearable sensors are frequently used to assess spatiotemporal, kinematic and kinetic parameters providing the means to establish an interactive control of the amputee-prosthesisenvironment system. Gait events and the gait phase detection of an amputee's locomotion are vital for controlling lower limb prosthetic devices. The paper presents an approach to real-time gait event detection for lower limb amputees using a wireless gyroscope attached to the shank when performing level ground and ramp activities. The results were validated using both healthy and amputee subjects and showed that the time differences in identifying Initial Contact (IC) and Toe Off (TO) events were larger in a transfemoral amputee when compared to the control subjects and a transtibial amputee (TTA). Overall, the time difference latency lies within a range of ± 50 ms while the detection rate was 100% for all activities. Based on the validated results, the IC and TO events can be accurately detected using the proposed system in both control subjects and amputees when performing activities of daily living and can also be utilized in the clinical setup for rehabilitation and assessing the performance of lower limb prosthesis users.

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ReuseUnless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Overall, detection accuracy was 99.78% for all the events in both groups. Based on the validated results, the proposed system can be used to accurately detect the temporal gait events in real-time that leads to the detection of gait phase system and therefore, can be utilized in gait analysis applications and the control of lower limb prostheses.

Abstract-Events and phases detection of the human gait are vital for controlling prosthesis, orthosis and functional electrical stimulation (FES) systems. Wearable sensors are inexpensive, portable and have fast processing capability. They are frequently used to assess spatio-temporal, kinematic and kinetic parameters of the human gait which in turn provide more details about the human voluntary control and amputeeprosthesis interaction. This paper presents a reliable real-time gait event detection algorithm based on simple heuristics approach, applicable to signals from tri-axial gyroscope for lower limb amputees during ramp ascending and descending. Experimental validation is done by comparing the results of gyroscope signal with footswitches. For healthy subjects, the mean difference between events detected by gyroscope and footswitches is 14 ms and 10.5 ms for initial contact (IC) whereas for toe off (TO) it is -5 ms and -25 ms for ramp up and down respectively. For transfemoral amputee, the error is slightly higher either due to the placement of footswitches underneath the foot or the lack of proper knee flexion and ankle plantarflexion/dorsiflexion during ramp up and down. Finally, repeatability tests showed promising results.

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Abstract-Gait event detection is important for intent predication in lower limb prostheses and exoskeletons during different activities. Human gait cycle is divided into two main phases i.e. swing phase and stance phase. Initial contact (IC) with the ground indicate the start of stance phase while Toe Off (TO) is the start of swing phase. This article presents algorithm based on set of heuristic rules for gait event detection using a single gyroscope attached on shank of subjects performing activities of daily living such as normal walking, fast walking, ramp ascending and ramp descending. The algorithm sequentially detected gait events like IC, TO, Midswing (MSw) and Midstance (MSt). Results were compared with the reference pressure measurement system using Flexiforce footswitches (FSW). The mean difference error between the reference and proposed system was for IC is about +4ms and for TO is about -6.5ms. The results showed that proposed algorithm achieved high detection performance compared to the existing algorithms and will lead to powerful tool to develop an intent recognition system for lower limb amputees. I. INTRODUCTIONLocomotion is crucial for human during activities of daily living (ADLs) as it plays an important role in gait efficiency and task progression. Patients with pathologic gait suffer from higher energy consumption and risk of falls. Gait analysis and event detection has been used in different applications using ambulatory gait systems to evaluate and improve patients' motilities and to control the functional electrical stimulation (FES) [1][2][3].Gait events can be detected using either force based measurement systems by means of footswitches such as force sensitive resistors (FSR) [4], or wearable sensor such as Inertia Measurement Unit (IMU) [5]. To perform outdoor activities for longer period of time, it is crucial to use the systems which are reliable, portable, small, inexpensive, and with low power consumption [6][7][8].Many researchers have used wearable sensors (accelerometers and gyroscopes) for analysis of spatiotemporal gait parameters during ADLs [9,[20][21]. Gyroscopes have been applied for detecting the gait events for triggering [10] amputees [20]. Locating the gyroscope on shank has many advantages as opposed to other parts of the human body [12], such as less soft tissue muscles at shank compared to thigh. In addition, gyroscope placed at shank is acceptable accurately in healthy and pathological subjects [13,14].Sabatini et al.[15] developed a gait event detection system for analysis of incline walking based on a single gyroscope attached on the foot of healthy subjects. However, placing gyroscope on shank provides ease of use as compared to its placement on foot as it provides less signal variability between the subjects. P. Catalfamo et al.[16] used a single gyroscope placed on the shank for detection of initial contact (IC) and foot off (FO) in subjects walking up and down on inclined surface and level ground. The results were compared with a reference system of foot ...

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