Experiment of Vibrational Cues for Gait Asymmetry in Stroke Patients

Muhammad Raheel Afzal(무하마드 라힐 아파잘),Hosu Lee(이호수),MinKyun Oh(오민균),YoungSook Park(박영숙),JungWon Yoon(윤정원) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.4

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

Afzal, Muhammad Raheel,Eizad, Amre,Palo Peñ,a, Carlos Ernesto,Yoon, Jungwon Hindawi 2018 Journal of healthcare engineering Vol.2018 No.-

<P>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 subject's 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 (<I>p</I> < 0.05) and ML trunk acceleration (<I>p</I> < 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.</P>

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

Afzal, Muhammad Raheel,Oh, Min-Kyun,Lee, Chang-Hee,Park, Young Sook,Yoon, Jungwon Hindawi Publishing Corporation 2015 BioMed research international Vol.2015 No.-

<P>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.</P>

Design of a Haptic Cane for Walking Stability and Rehabilitation

Muhammad Raheel Afzal,Irfan Hussain,Yasir Jan,Jungwon Yoon 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

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 patient’s 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 support’s 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.

Development of a Wearable Device based on Reaction Wheels to deliver Kinesthetic Cues for Balance Training

Muhammad Raheel Afzal,Carlos Ernesto Palo Pena,Jungwon Yoon 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

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 participant’s 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.

Single aptamer-based bio-chemo-mechanically hybrid system for capturing of target biomolecules with acoustofluidics

Raheel Ahmad,Ghulam Destgeer,Muhammad Afzal,Husnain Ahmed,Jin Ho Jung,Jinsoo Park,Kwangseok Park,Hyung Jin Sung 한국가시화정보학회 2017 한국가시화정보학회 학술발표대회 논문집 Vol.2017 No.5

We designed a robust bio-chemo-mechanical hybrid system capable to capture and separate specific target molecules. The system composed of aptamer15 modified streptavidin-coated polystyrene microsphere (PSMs-apt15) and acoustofluidic device to show non-destructive target molecule separation. In this study, thrombin is selected as target molecule. First, the thrombin was captured by target-specific aptamer15 functionalized on PSMs (PSMs-apt15-thrombin) from a mixture of protein solution and separated with acoustofluidic device which consist of single-layered starting polydimethylsiloxane (PDMS) microchannel with interdigital transducer (IDT) patterned on lithium niobate (LiNbO3) substrate to produce high frequency (130 MHz) travelling surface acoustic waves (TSAWs). Once the IDT was actuated, the thrombin captured complex (PSMs-apt15-thrombin) were separated from the proteins solution due to the vertical component of acoustic radiation force, as >1 for green fluorescent microsphere and collected at outlet 2 by sheath focusing, while other proteins solution with some unbound thrombin passed through outlet 1. This hybrid system based on TSAWs could greatly enable the separation of various low abundant protein biomarkers.

Acoustic Wave-Driven Functionalized Particles for Aptamer-Based Target Biomolecule Separation

Ahmad, Raheel,Destgeer, Ghulam,Afzal, Muhammad,Park, Jinsoo,Ahmed, Husnain,Jung, Jin Ho,Park, Kwangseok,Yoon, Tae-Sung,Sung, Hyung Jin American Chemical Society 2017 ANALYTICAL CHEMISTRY - Vol.89 No.24

<P>We developed a hybrid microfluidic device that utilized acoustic waves to drive functionalized microparticles inside a continuous flow microchannel and to separate particle-conjugated target proteins from a complex fluid. The acoustofluidic device is composed of an interdigitated transducer that produces high-frequency surface acoustic waves (SAW) and a polydimethylsiloxane (PDMS) microfluidic channel. The SAW interacted with the sample fluid inside the microchannel and deflected particles from their original streamlines to achieve separation. Streptavidin-functionalized polystyrene (PS) microparticles were used to capture aptamer (single-stranded DNA) labeled at one end with a biotin molecule. The free end of the customized aptamer15 (apt15), which was attached to the microparticles via streptavidin–biotin linkage to form the PS–apt15 conjugate, was used to capture the model target protein, thrombin (th), by binding at exosite I to form the PS–apt15–th complex. We demonstrated that the PS–apt15 conjugate selectively captured thrombin molecules in a complex fluid. After the PS–apt15–th complex was formed, the sample fluid was pumped through a PDMS microchannel along with two buffer sheath flows that hydrodynamically focused the sample flow prior to SAW exposure for PS–apt15–th separation from the non-target proteins. We successfully separated thrombin from mCardinal2 and human serum using the proposed acoustofluidic device.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2017/ancham.2017.89.issue-24/acs.analchem.7b03474/production/images/medium/ac-2017-03474b_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac7b03474'>ACS Electronic Supporting Info</A></P>

Design of a Haptic Walker system based on cable driven actuator for Lower Limb Rehabilitation

Hosu Lee,Muhammad Raheel Afzal,Jungwon Yoon 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

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.

A Wearable Reaction Wheel based Kinesthetic Biofeedback Device for Delivery of Balance Cues

Amre Eizad,Muhammad Raheel Afzal,Hosu Lee,Jungwon Yoon,Sung-Ki Lyu 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

In order to explore mobile applications of kinesthetic cues, we recently developed a system for generating kinesthetic cues on the user’s back. Carrying on from that work, in this paper we present a completely redesigned system that utilizes a pair of reaction wheels to generate torques on the system which in-turn are perceived by the user as directed force cues being delivered to their back. It is a wearable device that wirelessly takes commands from a PC and can generate leftward and rightward directed cues. The system was tested with healthy adults with two distinct objectives. The first was to determine how well they can perceive the cues and also to determine the effect of training on cue perception. The second was to determine the effect on standing balance of directed force cues delivered as biofeedback by the system. The results show that the device can effectively deliver directed kinesthetic cues to the user without becoming a source of discomfort, and biofeedback delivered through this system aids in maintaining balance. Thus, it is indicated that the device presented here is a viable means of delivering directed kinesthetic cues to a user and thus warrants further exploration of its possible applications.

Design of an Assistance Robot for Patients Suffering from Paraplegia

Shakir Khan,Muhammad Fahad Zeb,Nouman Ghafoor,Saad Jamshed,Muhammad Raheel Afzal,Amre Eizad 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10

The people with disabled lower limbs find it difficult to lead an independent life and the lack of upper body exercise may lead to disuse ailment. Various studies have shown that both children and adults benefit substantially from access to a means of independent mobility. Independent mobility is a dream for every person with some or the other physical disability especially in the case of paraplegics. In the research presented in this paper, an assistance platform was developed to help the paraplegic and elderly people by providing the ability to stand-up and move about. Virtual prototype technology was used to make the design and development of the robot more efficient using Solid-works™. The device developed may be used for rehabilitation of people recovering from extended periods of limb disuse and for paraplegic patients. Although some commercialized training machines and some developed lower-limb rehabilitation robots can perform adequate motion functions during lower limb training programs but the weight, size and cost of these devices limits their possibilities of use. In contrast, the proposed design has the potential to be used among the middle socio-economic class as a product in daily household works of the paraplegic patients.