Vinod Sharma

Participatory design in the development of the wheelchair convoy system

BackgroundIn long-term care environments, residents who have severe mobility deficits are typically transported by having another person push the individual in a manual wheelchair. This practice is inefficient and encourages staff to hurry to complete the process, thereby setting the stage for unsafe practices. Furthermore, the time involved in assembling multiple individuals with disabilities often deters their participation in group activities.MethodsThe Wheelchair Convoy System (WCS) is being developed to allow a single caregiver to move multiple individuals without removing them from their wheelchairs. The WCS will consist of a processor, and a flexible cord linking each wheelchair to the wheelchair in front of it. A Participatory Design approach – in which several iterations of design, fabrication and evaluation are used to elicit feedback from users – was used.ResultsAn iterative cycle of development and evaluation was followed through five prototypes of the device. The third and fourth prototypes were evaluated in unmanned field trials at J. Iverson Riddle Development Center. The prototypes were used to form a convoy of three wheelchairs that successfully completed a series of navigation tasks.ConclusionA Participatory Design approach to the project allowed the design of the WCS to quickly evolve towards a viable solution. The design that emerged by the end of the fifth development cycle bore little resemblance to the initial design, but successfully met the projects design criteria. Additional development and testing is planned to further refine the system.

A prototype power assist wheelchair that provides for obstacle detection and avoidance for those with visual impairments

BackgroundAlmost 10% of all individuals who are legally blind also have a mobility impairment. The majority of these individuals are dependent on others for mobility. The Smart Power Assistance Module (SPAM) for manual wheelchairs is being developed to provide independent mobility for this population.MethodsA prototype of the SPAM has been developed using Yamaha JWII power assist hubs, sonar and infrared rangefinders, and a microprocessor. The prototype limits the user to moving straight forward, straight backward, or turning in place, and increases the resistance of the wheels based on the proximity of obstacles. The result is haptic feedback to the user regarding the environment surrounding the wheelchair.ResultsThe prototype has been evaluated with four blindfolded able-bodied users and one individual who is blind but not mobility impaired. For all individuals, the prototype reduced the number of collisions on a simple navigation task.ConclusionThe prototype demonstrates the feasibility of providing navigation assistance to manual wheelchair users, but several shortcomings of the system were identified to be addressed in a second generation prototype.

SPARK: Personalized Parkinson Disease Interventions through Synergy between a Smartphone and a Smartwatch

Parkinson disease (PD) is a neurodegenerative disorder afflicting more than 1 million aging Americans, incurring

Predicting Methylphenidate Response in ADHD Using Machine Learning Approaches

23 billion in annual medical costs in the U.S. alone. Approximately 90% Parkinson patients undergoing treatment have mobility related problems related to medication which prevent them doing their activities of daily living. Efficient management of PD requires complex medication regimens specifically titrated to individuals’ needs. These personalized regimens are difficult to maintain for the patient and difficult to prescribe for a physician in the few minutes available during office visits. Diverging from current form of laboratory-ridden wearable sensor technologies, we have developed SPARK, a framework that leverages a synergistic combination of Smartphone and Smartwatch in monitoring multidimensional symptoms – such as facial tremors, dysfunctional speech, limb dyskinesia, and gait abnormalities. In addition, SPARK allows physicians to conduct effective tele-interventions on PD patients when they are in non-clinical settings (e.g., at home or work). Initial case series that use SPARK framework show promising results of monitoring multidimensional PD symptoms and provide a glimpse of its potential use in real-world, personalized PD interventions.

Performance testing of collision-avoidance system for power wheelchairs

Background: There are no objective, biological markers that can robustly predict methylphenidate response in attention deficit hyperactivity disorder. This study aimed to examine whether applying machine learning approaches to pretreatment demographic, clinical questionnaire, environmental, neuropsychological, neuroimaging, and genetic information can predict therapeutic response following methylphenidate administration. Methods: The present study included 83 attention deficit hyperactivity disorder youth. At baseline, parents completed the ADHD Rating Scale-IV and Disruptive Behavior Disorder rating scale, and participants undertook the continuous performance test, Stroop color word test, and resting-state functional MRI scans. The dopamine transporter gene, dopamine D4 receptor gene, alpha-2A adrenergic receptor gene (ADRA2A) and norepinephrine transporter gene polymorphisms, and blood lead and urine cotinine levels were also measured. The participants were enrolled in an 8-week, open-label trial of methylphenidate. Four different machine learning algorithms were used for data analysis. Results: Support vector machine classification accuracy was 84.6% (area under receiver operating characteristic curve 0.84) for predicting methylphenidate response. The age, weight, ADRA2A MspI and DraI polymorphisms, lead level, Stroop color word test performance, and oppositional symptoms of Disruptive Behavior Disorder rating scale were identified as the most differentiating subset of features. Conclusions: Our results provide preliminary support to the translational development of support vector machine as an informative method that can assist in predicting treatment response in attention deficit hyperactivity disorder, though further work is required to provide enhanced levels of classification performance.

Evaluation of semiautonomous navigation assistance system for power wheelchairs with blindfolded nondisabled individuals

The Drive-Safe System (DSS) is a collision-avoidance system for power wheelchairs designed to support people with mobility impairments who also have visual, upper-limb, or cognitive impairments. The DSS uses a distributed approach to provide an add-on, shared-control, navigation-assistance solution. In this project, the DSS was tested for engineering goals such as sensor coverage, maximum safe speed, maximum detection distance, and power consumption while the wheelchair was stationary or driven by an investigator. Results indicate that the DSS provided uniform, reliable sensor coverage around the wheelchair; detected obstacles as small as 3.2 mm at distances of at least 1.6 m; and attained a maximum safe speed of 4.2 km/h. The DSS can drive reliably as close as 15.2 cm from a wall, traverse doorways as narrow as 81.3 cm without interrupting forward movement, and reduce wheelchair battery life by only 3%. These results have implications for a practical system to support safe, independent mobility for veterans who acquire multiple disabilities during Active Duty or later in life. These tests indicate that a system utilizing relatively low cost ultrasound, infrared, and force sensors can effectively detect obstacles in the vicinity of a wheelchair.

Clinical evaluation of semiautonomous smart wheelchair architecture (Drive-Safe System) with visually impaired individuals.

Some individuals with disabilities are denied powered mobility because they lack the visual, motor, and/or cognitive skills required to safely operate a power wheelchair. The Drive-Safe System (DSS) is an add-on, distributed, shared-control navigation assistance system for power wheelchairs intended to provide safe and independent mobility to such individuals. The DSS is a human-machine system in which the user is responsible for high-level control of the wheelchair, such as choosing the destination, path planning, and basic navigation actions, while the DSS overrides unsafe maneuvers through autonomous collision avoidance, wall following, and door crossing. In this project, the DSS was clinically evaluated in a controlled laboratory with blindfolded, nondisabled individuals. Further, these individuals performance with the DSS was compared with standard cane use for navigation assistance by people with visual impairments. Results indicate that compared with a cane, the DSS significantly reduced the number of collisions. Users rated the DSS favorably even though they took longer to navigate the same obstacle course than they would have using a standard long cane. Participants experienced less physical demand, effort, and frustration when using the DSS as compared with a cane. These findings suggest that the DSS can be a viable powered mobility solution for wheelchair users with visual impairments.

Differentiating the Effects of Familial Risk for Alcohol Dependence and Prenatal Exposure to Alcohol on Offspring Brain Morphology

Nonambulatory, visually impaired individuals mostly rely on caregivers for their day-to-day mobility needs. The Drive-Safe System (DSS) is a modular, semiautonomous smart wheelchair system aimed at providing independent mobility to people with visual and mobility impairments. In this project, clinical evaluation of the DSS was performed in a controlled laboratory setting with individuals who have visual impairment but no mobility impairment. Their performance using DSS was compared with their performance using a standard cane for navigation assistance. Participants rated their subjective appraisal of the DSS by using the National Aeronautics and Space Administration-Task Load Index inventory. DSS significantly reduced the number and severity of collisions compared with using a cane alone and without increasing the time required to complete the task. Users rated DSS favorably; they experienced less physical demand when using the DSS, but did not feel any difference in perceived effort, mental demand, and level of frustration when using the DSS alone or along with a cane in comparison with using a cane alone. These findings suggest that the DSS can be a safe, reliable, and easy-to-learn and operate independent mobility solution for visually impaired wheelchair users.

Lifetime use of cannabis from longitudinal assessments, cannabinoid receptor (CNR1) variation, and reduced volume of the right anterior cingulate.

BACKGROUNDnOffspring with a family history of alcohol dependence (AD) have been shown to have altered structural and functional integrity of corticolimbic brain structures. Similarly, prenatal exposure to alcohol is associated with a variety of structural and functional brain changes. The goal of this study was to differentiate the brain gray matter volumetric differences associated with familial risk and prenatal exposure to alcohol among offspring while controlling for lifetime personal exposures to alcohol and drugs.nnnMETHODSnA total of 52 high-risk (HR) offspring from maternal multiplex families with a high proportion of AD were studied along with 55 low-risk (LR) offspring. Voxel-based morphometric analysis was performed using statistical parametric mapping (SPM8) software using 3T structural images from these offspring to identify gray matter volume differences associated with familial risk and prenatal exposure.nnnRESULTSnSignificant familial risk group differences were seen with HR males showing reduced volume of the left inferior temporal, left fusiform, and left and right insula regions relative to LR males, controlling for prenatal exposure to alcohol drugs and cigarettes. HR females showed a reduction in the right fusiform but also showed a reduction in volume in portions of the cerebellum (left crus I and left lobe 8). Prenatal alcohol exposure effects, assessed within the familial HR group, was associated with reduced right middle cingulum and left middle temporal volume. Even low exposure resulting from mothers drinking in amounts less than the median of those who drank (53 drinks or less over the course of the pregnancy) showed a reduction in volume in the right anterior cingulum and in the left cerebellum (lobes 4 and 5).nnnCONCLUSIONSnFamilial risk for AD and prenatal exposure to alcohol and other drugs show independent effects on brain morphology.

Understanding User's Emotional Engagement to the Contents on a Smartphone Display: Psychiatric Prospective

Lifetime measures of cannabis use and co-occurring exposures were obtained from a longitudinal cohort followed an average of 13 years at the time they received a structural MRI scan. MRI scans were analyzed for 88 participants (mean age=25.9 years), 34 of whom were regular users of cannabis. Whole brain voxel based morphometry analyses (SPM8) were conducted using 50 voxel clusters at p=0.005. Controlling for age, familial risk, and gender, we found reduced volume in Regular Users compared to Non-Users, in the lingual gyrus, anterior cingulum (right and left), and the rolandic operculum (right). The right anterior cingulum reached family-wise error statistical significance at p=0.001, controlling for personal lifetime use of alcohol and cigarettes and any prenatal exposures. CNR1 haplotypes were formed from four CNR1 SNPs (rs806368, rs1049353, rs2023239, and rs6454674) and tested with level of cannabis exposure to assess their interactive effects on the lingual gyrus, cingulum (right and left) and rolandic operculum, regions showing cannabis exposure effects in the SPM8 analyses. These analyses used mixed model analyses (SPSS) to control for multiple potentially confounding variables. Level of cannabis exposure was associated with decreased volume of the right anterior cingulum and showed interaction effects with haplotype variation.