Mihai Ilea

Graphical interface that interprets the moments collected from the contact between the stump and socket

Mathematical modeling is an interdisciplinary scientific research field with a wide range of applications in bioengineering (biomechanics processes) and rehabilitation. The vast majority of quantitative models of Bioengineering are formulated in terms of differential equations. Modeling and simulating the Biomechanics of rehabilitation process is an area of major interest in the current medical research. In this study, we aimed to develop an interface graphics, allowing the changing rates of transfer between any two compartments of the vital blunt-socket system. One method to obtain the status of recovery and balance is to develop a mathematical model in order to reduce the time of assessment and prediction. Analysis of the strength and the speed of muscle contraction can be described using a model of mathematically hyperbolic, which could open new avenues for the optimal choice of specific transfer rates to the level of prosthesis. An optimal choice for the recovery method gives more chances to maintain and improve the quality of life of the patient after amputation. A wrong choice for recovery methods and of type of dentures can determine major changes in the position and orientation of the foot joints and may cause points pressure maxima stump area. Experimental data collected from pressure sensors can be used to determine if the forces, moments that can change loading rates and determine if it has achieved good contact when the initial prosthesis and residual limb socket.

Analyze of liner influence in transtibial prosthetic taking into account tribological aspects

An objective method is proposed to evaluate the performance of a prosthetic patient in order to choose an optimized pair of prosthetic material for liner and cup. The surface pressure map over the residual limb is monitored in order to identify the zones where the mechanical work over the skin is increased and a decision system identifies the most suitable liner-cup pair according to stump geometry, patients characteristics and friction coefficient between skin and liner. The pressure and forces are considered to be the best probable ones during a gait cycle (an average value during a predefined number of trials). Experimental results and simulation are presented.

Graphical interface for analyze of temperature of skin at skin-liner interface

Patients comfort is one of the most important issues in prosthetics Pressures and forces, at skin-liner interface play the most important role in evaluation of this requirement. Beside this, temperature is an important factor that must be considered for analyze and prevent the deterioration of skin in wearing prosthesis. A graphical interface that display and analyze the temperature of the skin at skin-liner interface is proposed in this paper. The software has modules for sensor calibration, display records and prediction of temperature in location where sensors are located as function of ambient temperature. The predictor is based on a linear interpolator/extrapolator that is used to evaluate the temperature during a normal cycle of gait (normal walk for a defined period).

Performance Optimization of Blunt-Prosthesis-Rod Complex with Tribological Considerations

The interface blunt-prosthesis from blunt-prosthesis-rod complex is the subject of stress and friction due to forces that act in the walking stage. The dermal wounds and patients discomfort sensation that can appear can be alleviated or predicted by analyzing the stump’s pressure map taking into account tribological aspects. There are many studied related to transtibial prosthesis but studies that analyze the transfemoral prosthesis are relative rare. A analyze of pressure in blunt-prosthesis complex for transfemoral sub-ischeal prosthesis is proposed during a complete gait cycle.The experiments used three types of liners and a standard type of socket. The areas that are subject of maximum stress and friction are identified as the value of forces of moments that act n stump during a gait cycle. An integral measure and functional ones are proposed to evaluate for influence of each factor that can contribute to optimization of prosthesis and an empirical formulas that connect these measure for prediction is suggested. Theoretical approaches are presented along with experimental results and further research directions.

A proposal for construction of the surface pressure map distribution with tribological considerations at stump-liner interface in prosthetic application

The authors propose a construction of surface pressure maps based on a liner and taken into consideration the tribological aspects for the constructions optimization of prosthesis. The methodology proposed can be used in achieving individualized kinetic schemes that adapt in real time to ensure an optimal and functional system in the blunt-prosthesis. The construction of the pressure map is made using six sensors and applies on a real case of an amputation below the level the knee. The three-dimensional modeling and the analysis by finite elements allow particularly unlimited variations, created by changing various parameters, each change resulting in a new model, which would not be possible in any of the direct methods of investigation.