The potency of optical and augmented reality mirror boxes in amputees and people with intact limbs

Phantom limb pain is the distressing problem experienced by many amputees, defined as a painful sensation perceived in the area of the missing body part. Phantom limb pain can be very severe and disabling. It continues to be experienced by two thirds of amputees, eight years post-amputation. Augmented reality has the ability to change a person’s sensory experience. More applications of this technology are gradually being utilised for therapeutic purposes as augmented environments can be used both to distract the attention of patients from excruciatingly painful experiences and to promote cortical re-mapping at the site from where the pain arises. Using Augmented Reality, an environment has been created where upper limb amputees can both view and control motion of their phantom limb to help alleviate phantom limb pain

A new eccentric geomagnetic dipole to give the correct dip pole locations

In this paper, we describe a new eccentric dipole model of the Earth’s magnetic field. The constraints under which the conventional eccentric dipole model is defined result in predicted dip pole locations that differ significantly from the measured locations. Here, we give a preliminary exposition of a new dipole model which, because it is constrained by the observed dip pole locations, overcomes this problem

Electromagnetic measurement of spinal curvature

In this paper, we describe an original mathematical technique for calculating the position and orientation of an electromagnetic coil from a minimum of four collinear magnetic field measurements. This problem arose in the development of a system for evaluating the efficacy of inflatable back rafts designed to mitigate complications that arise from the immobilisation of patients with suspected spinal injuries on spinal boards during transport to hospital. Electromagnetic markers are attached to points of interest on the back of an immobilised test subject. Spinal curvature is then measured by passing a magnetometer underneath the board

A Monocular Marker-Free Gait Measurement System

This paper presents a new, user-friendly, portable motion capture and gait analysis system for capturing and analyzing human gait, designed as a telemedicine tool to monitor remotely the progress of patients through treatment. The system requires minimal user input and simple single-camera filming (which can be acquired from a basic webcam) making it very accessible to nontechnical, nonclinical personnel. This system can allow gait studies to acquire a much larger data set and allow trained gait analysts to focus their skills on the interpretation phase of gait analysis. The design uses a novel motion capture method derived from spatiotemporal segmentation and model-based tracking. Testing is performed on four monocular, sagittal-view, sample gait videos. Results of modeling, tracking, and analysis stages are presented with standard gait graphs and parameters compared to manually acquired data

Multiple frequencies in the basal ganglia in Parkinson's disease

In recent years, the authors have developed what appears to be a very successful phenomenological model for analyzing the role of deep brain stimulation (DBS) in alleviating the symptoms of Parkinson's disease. In this paper, we extend the scope of the model by using it to predict the generation of new frequencies from networks tuned to a specific frequency, or indeed not self-oscillatory at all. We have discussed two principal cases: firstly where the constituent systems are coupled in an excitatory-excitatory fashion, which we designate by ``+/+''; and secondly where the constituent systems are coupled in an excitatory-inhibitory fashion, which we designate ``+/-''. The model predicts that from a basic system tuned to tremor frequency we can generate an unlimited range of frequencies. We illustrate in particular, starting from systems which are initially non-oscillatory, that when the coupling coefficient exceeds a certain value, the system begins to oscillate at an amplitude which increases with the coupling strength. Another very interesting feature, which has been shown by colleagues of ours to arise through the coupling of complicated networks based on the physiology of the basal ganglia, can be illustrated by the root locus method which shows that increasing and decreasing frequencies of oscillation, existing simultaneously, have the property that their geometric mean remains substantially constant as the coupling strength is varied. We feel that with the present approach, we have provided another tool for understanding the existence and interaction of pathological oscillations which underlie, not only Parkinson's disease, but other conditions such as Tourette's syndrome, depression and epilepsy

An Uncoupled Oscillator Model for evoked potential dynamical modelling

A mathematical model for evoked potentials is outlined. The model has been developed by considering phase synchronisation of the underlying neurological processes. Tbe model, consisting of an ensemble of uncoupled linear oscillators with a gaussian distribution of frequencies is shown to reproduce tbe typical response of PIOO visual evoked response. Tbe model structure is parallel in form and is considered to be pbysiologically realistic. It is also sbown that tbe calculated behaviour of tbe ensemble can be generated by a 2"" order linear differential equation with time varying coefficients, thus highlighting the fact that entirely different physical structures can generate identical responses

Augmenting the Reality of Phantom Limbs: Three Case Studies Using an Augmented Mirror Box Procedure

Phantom sensation and phantom pain are common after limb amputation. Previous research documents increased motor control of phantom limbs and alleviation of phantom limb pain through exposure to the “mirror box illusion.” This approach centers on the potential for vision and sensorimotor interactions to alter phantom limb perception. The applicability and flexibility of this intervention is limited by methodological constraints inherent in the use of conventional mirrors. This article reports the application of an "augmented reality" intervention that seeks to overcome these constraints. Three case studies are presented, and it is argued that augmented reality technology offers a promising new approach to the investigation of phantom experience and potentially to the treatment of phantom pain

Exploration of the Generation and Suppression of Pathological Oscillatory Neural Activity in a Model of Deep Brain Stimulation in Parkinsons disease

21st Bioengineering in Ireland Conference (BINI) 2015, Carton House, Maynooth, Co. Kildare, Ireland, 16-17 January 2015This study explores possible mechanisms for the generation of pathological neural oscillatory activity associated with Parkinson’s disease in theoretical models. The suppression of the model oscillations with high frequency stimulation, analogous to the use of deep brain stimulation (DBS) in the treatment of Parkinson's disease, is also examined. The relationship between oscillation amplitude and the amplitude of the applied stimulation is explored theoretically and then compared with experimental data recorded in patients.Science Foundation Irelan

Estimates of quantities in a Hall effect geodynamo theory

Currents, resistances, dynamo constant, Hall voltage coefficient and inductances are estimated for the author’s geodynamo theory incorporating the Hall Effect. It is concluded that the Hall Coefficient in the bulk liquid core of the Earth is approximately 1.512x10-1, orders of magnitude greater than in normal liquid metals. The ordering effect of enormous pressure is a possible cause

Preliminary results for a monocular marker-free gait measurement system

This paper presents results from a novel monocular marker-free gait measurement system. The system was designed for physical and occupational therapists to monitor the progress of patients through therapy. It is based on a novel human motion capture method derived from model-based tracking. Testing is performed on two monocular, sagittal-view, sample gait videos – one with both the environment and the subject’s appearance and movement restricted and one in a natural environment with unrestricted clothing and motion. Results of the modelling, tracking and analysis stages are presented along with standard gait graphs and parameters