Muhammad Raheel Afzal

A Portable Gait Asymmetry Rehabilitation System for Individuals with Stroke Using a Vibrotactile Feedback

Gait asymmetry caused by hemiparesis results in reduced gait efficiency and reduced activity levels. In this paper, a portable rehabilitation device is proposed that can serve as a tool in diagnosing gait abnormalities in individuals with stroke and has the capability of providing vibration feedback to help compensate for the asymmetric gait. Force-sensitive resistor (FSR) based insoles are used to detect ground contact and estimate stance time. A controller (Arduino) provides different vibration feedback based on the gait phase measurement. It also allows wireless interaction with a personal computer (PC) workstation using the XBee transceiver module, featuring data logging capabilities for subsequent analysis. Walking trials conducted with healthy young subjects allowed us to observe that the system can influence abnormality in the gait. The results of trials showed that a vibration cue based on temporal information was more effective than intensity information. With clinical experiments conducted for individuals with stroke, significant improvement in gait symmetry was observed with minimal disturbance caused to the balance and gait speed as an effect of the biofeedback. Future studies of the long-term rehabilitation effects of the proposed system and further improvements to the system will result in an inexpensive, easy-to-use, and effective rehabilitation device.

Design of a haptic cane for walking stability and rehabilitation

Rehabilitation is suggested to be achieved by natural walk, and it may require assistive devices. Assistance provided should motivate the patient to use his own muscle strength rather than be dependent upon the device. Therefore, the devices should only provide minimum support required for the safety, stability, confidence building and guidance. These can be achieved with light touch cue provided at the patients hands. The proposed haptic cane design has an active haptic handle that can give light touch cue depending upon the body orientation sensed through smartphone. The active haptic handle can be manipulated by a Pantograph mechanism. The Pantograph and arm supports positions and orientation are adjustable. The handle and arm support are mounted on the cane having a single wheel, coupled with motor, shaft encoder and an active brake, for achieving a controlled movement. The proposed design will be able to provide rehabilitation and postural stability for the patients.

Analysis of Active Haptic Feedback Effects on Standing Stability

Upright standing posture is maintained through a continous sensing and muslce activation by the brain. Any relevant disability may result in an instable posture and thus increased body sway. To decrease body sway haptic feedback sensing can be used. This paper presents an experimental study about comparison of reduction in body sways using different haptic feedbacks. Anteroposterior (AP) and Mediolateral (ML) body sway were measured through a smartphone, and active feedback was provided using Phantom Omni device. Tests were performed in various postures and the body sway was analyzed with continuous haptic feedbacks. The study shows that active guidance to user produces more stability compared with sensory feedback.

Haptic based gait rehabilitation system for stroke patients

Among most existing gait rehabilitation robots, it is difficult to find adequate devices for gait rehabilitation of chronic stroke patients who can already stand and move but still need to rehabilitate the affected lower limb through simple, compact, and easy-to use devices. This paper presents a novel haptic based gait rehabilitation system (HGRS) which has the potential to provide over-ground gait training regimens for post-stroke ambulatory subjects. It consists of a portable cane for kinesthetic sensing and a wearable vibrotactor array for tactile biofeedback. Contact of user with the handle provides light grip force, it serves the purpose of balance assurance and increased muscle activity through light touch concept and vibrotactors contribute in enhancing the gait modification through afferent signal of vibration. Walking trials conducted with stroke patients indicate increased muscle activation and balance, and improved temporal symmetry with use of HGRS. HGRS is capable of assisting physical therapists in training individuals with stroke suffering from gait abnormalities. In addition, it is easy to use and low-cost which makes it reachable to a vast domain of subjects suffering from gait abnormalities.

Development of an augmented feedback system for training of gait improvement using vibrotactile cues

Gait rehabilitation following stroke is often stated as the primary goal to improve quality of life. A wearable augmented feedback system which provides vibrotactile cues for post-stroke gait training is presented in this research. The system is capable of determining temporal gait parameters and thus identifies gait irregularities. A pair of custom-made insole, containing four Force Sensitive Resistors (FSRs) each, is being utilized to detect gait phase information. Each Insole is connected to a lily pad Arduino. Besides, the lily pad communicates with an XBee Wi-Fi, to provide connectivity with an operator PC in real-time. At the PC, the data from FSRs is being received in a custom-made LabVIEW® program. This program processes the data for real-time detection of temporal gait parameters and phase transitions. At the wearable system six vibrotactors are positioned at each shank to provide vibrotactile cues. These vibrotactors receive command of actuation from the LabVIEW program at PC, through lilypad over the XBee Wi-Fi. In the current research, a time-discrete vibrotactile cue is implemented for providing augmented feedback during walking. Five healthy subjects participated in an experimental trial to determine the capability of the system in delivery of time-discrete vibrotactile cues. Results indicate the systems usability and effectiveness in provision of augmented feedback for gait training.

Development of a multimodal biofeedback system for balance training

Biofeedback based exercises results in post-training improvements of postural stability. Various modalities have been used to provide a biofeedback system for training of balance control and postural stability. However a multimodal biofeedback system can offer more individualized training methods and hence provide therapists with a comprehensive solution for diverse patients. Individually, visual and haptic biofeedback has been identified as effective to reduce body sway in patients suffering from balance. So we have developed a novel multimodal system which provides biofeedback with both visual and haptic modality. Our system features a waist-attached smartphone, software running on a computer, a dedicated monitor for visual biofeedback and a dedicated Phantom Omni® device for haptic biofeedback. Experimental trials conducted with young healthy subjects demonstrate the effectiveness of the biofeedback system. The results indicate that a multimodal biofeedback system is found to be more effective in comparison with lone biofeedback of visual or haptic modality.

Detection of Peste des Petits Ruminants Viral RNA in Fecal Samples of Goats after an Outbreak in Punjab Province of Pakistan: A Longitudinal Study.

Peste des petits ruminants (PPR) is a highly contagious viral disease of domestic and wild small ruminants and thus has serious socioeconomic implications. In Pakistan, during the year 2012-2013, estimated losses due to PPR were worth Rs. 31.51 billions. Close contact between infected and susceptible animals is an important route of transmission of PPR. Therefore, carrier animals play an important role in unnoticed transmission of PPR. The objective of the study was to investigate the detection of PPR virus in goats recovered from PPR. A suspected PPR outbreak was investigated and confirmed as PPR after analysing appropriate samples collected from infected animals using rRT-PCR. A longitudinal study was conducted over the period of 16 weeks to ascertain the detection of PPR virus (PPRV) in faecal samples of recovered goats. Ninety-six (96) faecal samples from each sampling were collected at 4, 8, 12, and 16 weeks after the outbreak. Faecal samples were analysed using rRT-PCR. Of 96 from each sampling a total of 46, 37, 29, and 25 samples were positive for PPR viral genome at 4, 8, 12, and 16 weeks, respectively, after recovery. Attempts were made for the isolation of PPR virus on Vero cells, but results were negative. These results indicated the detection of PPR viral RNA up to 16 weeks after infection. Therefore, these results may help in the future epidemiology of PPR virus shedding and possible role as source of silent infection for healthy animals especially when there is no history of any outbreak in nearby flock or area.

Evaluating the Effects of Kinesthetic Biofeedback Delivered Using Reaction Wheels on Standing Balance

Aging, injury, or ailments can contribute to impaired balance control and increase the risk of falling. Provision of light touch augments the sense of balance and can thus reduce the amount of body sway. In this study, a wearable reaction wheel-based system is used to deliver light touch-based balance biofeedback on the subjects back. The system can sense torso tilt and, using reaction wheels, generates light touch. A group of 7 healthy young individuals performed balance tasks under 12 trial combinations based on two conditions each of standing stance and surface types and three of biofeedback device status. Torso tilt data, collected from a waist-mounted smartphone during all the trials, were analyzed to determine the efficacy of the system. Provision of biofeedback by the device significantly reduced RMS of mediolateral (ML) trunk tilt (p < 0.05) and ML trunk acceleration (p < 0.05). Repeated measures ANOVA revealed significant interaction between stance and surface on reduction in RMS of ML trunk tilt, AP trunk tilt, ML trunk acceleration, and AP trunk acceleration. The device shows promise for further applications such as virtual reality interaction and gait rehabilitation.

Development of a wearable device based on reaction wheels to deliver kinesthetic cues for balance training

Reaction Wheels (RW) have traditionally been used in spacecraft to control their attitude. This paper presents a novel application of RW to deliver kinesthetic cues for balance training through the development of a wearable device that can deliver kinesthetic cues alike light touch. A prototype wearable device has been designed that has 4 RWs as main actuators to generate kinesthetic cues, and additionally the system includes a wireless interface to a computer for evaluation purposes. Two modes of controlling the device output were implemented, PID and Saturated PID (S.PID). For experimental verification, seven young healthy participants performed several balance tasks. The results thus obtained indicate significant (P<0.05) difference in participants Mediolateral (ML) trunk sway between experiments conducted without and with kinesthetic cues, and differences in ML trunk sway between PID and S.PID control modes. Thus the relatively small torques delivered by RWs of the proposed device can provide kinesthetic cues for balance assistance.

Design of a haptic walker system based on cable driven actuator for lower limb rehabilitation

In recent years, several robotic devices have been developed for lower limb rehabilitation. However, the post-training functional improvements in gait abilities after using those devices are reported to be either similar to conventional rehabilitation therapy or even lower in some cases. Meanwhile, those existing devices have several drawbacks such as heavy, complex mechanisms, expensive, restriction of mobility. Thus, this paper suggests a system which can help to realize lower limb joint torque on real ground without restriction of mobility. A walker combined with wire driven actuation of lower limb is proposed. The advantages of the proposed system are that the system is lightweight, easy to wear, can be implemented with simplistic control scheme and provides walking experience on the actual ground. In this paper, we have presented the design of the proposed device and performed analysis of its dynamics by using ADAMS® to assess its actuation. In future work the optimization of the design and fabrication of the system will be carried out.