sharmila nageswaran
VIT University, Biomedical Engineering, Faculty Member
Research Interests:
Mechanical valve implanted in mitral position has a tremendous effect on the flow dynamics in Left Ventricle (LV). The purpose of this study is to develop a new valve configuration to reduce the vortex ring formation caused by an... more
Mechanical valve implanted in mitral position has a tremendous effect on the flow dynamics in Left Ventricle (LV). The purpose of this study is to develop a new valve configuration to reduce the vortex ring formation caused by an artificial heart valve in an isovolumetric environment to generate a smoother flow field. Flow Inhibitors (FI) were built on the proximal end of the leaflet of various shapes and sizes to understand their effect on flow dynamics. The test geometries were designed based on the principles of Bernoulli's law of fluid dynamics, pressure staging, and counter disturbance. In this research, equally spaced FI with centralized flow showed a lower and gradual pressure gradient as opposed to the control valve that was used earlier in the study done with a 27mm St. Jude mechanical valve. The pressure gradient dropped gradually from 1.4 Pa to 0.3 Pa as compared to a sudden drop in pressure in the control valve from 1.3 Pa to 0.2 Pa. The velocity value set was 0.8 m/s for simulation which dropped to 0.4 m/s in equally spaced FI centralized flow valve as compared to 0.3 m/s in the control valve. When compared on the basis of smoothness of flow field and gradual drop in the pressure, the former is weighted to be a better design. Flow inhibitor coupled with pressure staging method proved to be effective in enhancing the performance of bileaflet valve.
Research Interests:
Foot is the basic supporting system of the body. It will bear the weight of body structure and helps us in static and dynamic stability. In our day to day activity, the people from various professions like surgeons, lecturers or common... more
Foot is the basic supporting system of the body. It will bear the weight of body structure and helps us in static and dynamic stability. In our day to day activity, the people from various professions like surgeons, lecturers or common people have a tendency to shift their whole body weight to one foot unknowingly which can cause excess wear and tear in leg. So, if we can design a footwear which can alert the users when there is a distribution of weight mismatch between two legs, it would be of a great clinical need at this hour.
Research Interests:
Pressure ulcers are the major problem in the stroke management and rehabilitation. Prevention of pressure ulcer is of keen interest and is achieved by frequently changing the position of patient on the mattress. However, the care needs to... more
Pressure ulcers are the major problem in the stroke management and rehabilitation. Prevention of pressure ulcer is of keen interest and is achieved by frequently changing the position of patient on the mattress. However, the care needs to be intensive to address this issue; else it would lead to pressure ulcer or bed sores formation. Skin surface over the bony prominences provide comparatively more pressure than the other regions. Therefore they are called as pressure vulnerable regions. Skin over these regions is more susceptible for formation of ulcers. An engineering approach is needed to shift the accumulating pressure from the pressure vulnerable regions. Although pressure sensed in these region would be more than that of which sensed in other regions, shifting protocol has to be designed to channelize or to grade the pressure shift in order to avoid any injuries to the non pressure vulnerable region. This paper aims at devising one such protocol using MATLab and thereby design...
In developing countries, patients with disabilities are often deprived of getting treated at rehabilitation centres with modern equipments and technologies. In India as per the 2011 census about 2.21% of the population suffer with... more
In developing countries, patients with disabilities are often deprived of getting treated at rehabilitation centres with modern equipments and technologies. In India as per the 2011 census about 2.21% of the population suffer with disabilities due to either visual, auditory, speech or locomotor dysfunctions. Locomotor disability is seen predominantly in about 20.27% of patients amongst the various other disabilities. Measurement of the foot deformities is very essential for the fabrication of orthosis. The techniques of foot measurement that are presently used needs either the patient's foot outline measurement to be sent to the rehabilitation centre or cast measurement to be taken using plaster of paris mould. The need of the hour is for a technique that is quick and doesn't require the patient to visit the rehabilitation centre. This paper suggests a method in which the digital photograph of the foot outline of a remotely located patient would help to acquire the required dimensions of the foot. The developed technique of measuring foot outline has been validated by comparing n=103 pairs of digital photographs of patient's foot outline with that of the manual method of measurement. Error in measurement using this technique was found to be 2.83 ±0.39mm. Also Pearson correlation coefficient of measured foot length and width were 0.991±0.005 for a 95% Confidence Interval and was very significant (p<0.001). Acquiring foot measurement of remotely located patients through these methods can help the clinical experts in the rehabilitation centre fabricate appropriate foot wear or orthotic device for the patient.
Research Interests:
Research Interests:
Annually, 15 million in world population experiences stroke. Nearly 9 million stroke survivors every year experience mild to severe disability. The loss of upper extremity function in stroke survivors still remains a major... more
Annually, 15 million in world population experiences stroke. Nearly 9 million stroke survivors every year experience mild to severe disability. The loss of upper extremity function in stroke survivors still remains a major rehabilitationchallenge. The proposed EMG based FES system can be used for effective upper limb motor re-education in post stroke upper limb rehabilitation. The governing feature of the designed system is its synchronous activation, in which the FES stimulation is dependent on the amplitude of the EMG signal acquired from the unaffected upper limb muscle of the hemiplegic patient. This proportionate operation eliminates the undesirable damage to the patient’s skin by generating stimulus in proportion to voluntary EMG signals. This feature overcomes the disadvantages of currently available manual motor re-education systems. This model can be used in home-based post stroke rehabilitation, to effectively improve the upper limb functions.