Prevalence of heat and perspiration discomfort inside prostheses: literature review.

People with limb amputation deal with thermal stresses in their daily activities. Unfortunately, in the majority of this population, all thermal transfer mechanisms, including convection, radiation, evaporation, and conduction, can be disturbed due to the prosthetic socket barrier, decreased body surface area, and/or vascular disease. The thermal environment inside prosthetic sockets, in addition to decreased quality of life and prosthesis use, comfort, and satisfaction, could endanger people with amputation with a high risk of skin irritations. The current review explores the importance of thermal and perspiration discomfort inside prosthetic sockets by providing an insight into the prevalence of the problem. The literature search was performed in two databases, PubMed and Web of Knowledge, to find relevant articles. After considering the review criteria and hand-searching the reference sections of the selected studies, 38 studies were listed for review and data extraction. This review revealed that more than 53% of people with amputation in the selected studies experienced heat and/or perspiration discomfort inside their prostheses. In spite of great technological advances, current prostheses are unable to resolve this problem. Therefore, more attention must be paid by researchers, clinicians, and manufacturers of prosthetic components to thermal-related biomechanics of soft tissues, proper fabrication technique, material selection, and introduction of efficient thermoregulatory systems.This material was based on work supported by the Iran National Science Foundation

The prototype of a thermoregulatory system for measurement and control of temperature inside prosthetic socket

Thermal related problems with prostheses are common complaints of amputee people. This article aims to introduce a thermoregulatory technique as a potential solution for those problems in prostheses wearers. A smart thermoregulatory system was designed, manufactured, and installed on a phantom model of a prosthetic socket. It captured temperature data from 16 sensors positioned at the interface between the phantom model and a silicone liner and used their average for comparison with a defined set temperature to select required heating or cooling functions for thermal equilibrium. A thin layer of Aluminum was used to transfer temperature between thermal pump and different sites around the phantom model. The feasibility of this thermoregulatory technique was confirmed by its ability to provide thermal equilibrium. Further investigations to improve the design of thermoregulatory system are necessary including temperature transfer element and power consumption based on thermal capacity and thermal inertia of the residual limb. The smart thermoregulatory system by providing thermal equilibrium between two sides of a prosthetic silicone liner can control residual limb skin temperature and sweating. Consequently, it can improve quality of life in amputee people.N/

Temperature measurement and control system for transtibial prostheses: single subject clinical evaluation.

The snug fit of a prosthetic socket over the residual limb can disturb thermal balance and put skin integrity in jeopardy by providing an unpleasant and infectious environment. The prototype of a temperature measurement and control (TM&C) system was previously introduced to resolve thermal problems related to prostheses. This study evaluates its clinical application in a setting with reversal, single subject design. The TM&C system was installed on a fabricated prosthetic socket of a man with unilateral transtibial amputation. Skin temperature of the residual limb without prosthesis at baseline and with prosthesis during rest and walking was evaluated. The thermal sense and thermal comfort of the participant were also evaluated. The results showed different skin temperature around the residual limb with a temperature decrease tendency from proximal to distal. The TM&C system decreased skin temperature rise after prosthesis wearing. The same situation occurred during walking, but the thermal power of the TM&C system was insufficient to overcome heat build-up in some regions of the residual limb. The participant reported no significant change of thermal sense and thermal comfort. Further investigations are warranted to examine thermography pattern of the residual limb, thermal sense, and thermal comfort in people with amputation.N/

Temperature measurement and control system for transtibial prostheses: functional evaluation.

The accumulation of heat inside the prosthetic socket increases skin temperature and fosters perspiration, which consequently leads to high tissue stress, friction blister, discomfort, unpleasant odor, and decreased prosthesis suspension and use. In the present study, the prototype of a temperature measurement and control (TM&C) system was designed, fabricated, and functionally evaluated in a phantom model of the transtibial prosthetic socket. The TM&C system was comprised of 12 thermistors divided equally into two groups that arranged internal and external to a prosthetic silicone liner. Its control system was programmed to select the required heating or cooling function of a thermal pump to provide thermal equilibrium based on the amount of temperature difference from a defined set temperature, or the amount of difference between the mean temperature recorded by inside and outside thermistors. A thin layer of aluminum was used for thermal conduction between the thermal pump and different sites around the silicone liner. The results showed functionality of the TM&C system for thermoregulation inside the prosthetic socket. However, enhancing the structure of this TM&C system, increasing its thermal power, and decreasing its weight and cost are main priorities before further development.The Hong Kong Polytechnic University supported all expenses of functional evaluation. Moreover, The ST&G Corporation, South Korea, has donated silicone liners for functional evaluation. The authors received no more support for conduction of this stud

Customised design and manufacture of protective face masks combining a practitioner-friendly modelling approach and low-cost devices for digitising and additive manufacturing

This project analyses the viability of an efficient modelling approach using a semi-automatic algorithm within a Computer Aided Design (CAD) application in combination with low-cost digitising devices and low-cost Additive Manufacturing (AM) printers when designing and manufacturing patient-specific face masks. The aims of the study were to enable clinical practitioners to utilise the advantages of three-dimensional (3D) scanning, CAD and AM without having to be trained to use design/engineering software. Face features were captured using two 3D devices. The resulting meshes were compared via the Hausdorff Distance method. A semi-automatic modelling procedure was developed with ‘Rhinoceros’ and ‘Grasshopper’ to model the face mask and customise several features. With that procedure, volunteers modelled a face mask in less than 30 minutes in their first attempt. The resulting virtual mask was manufactured with two AM printers. An initial economic study indicated that the presented approach offers a feasible alternative to the current practices

An efficient application of goal programming to tackle multiobjective problems with recurring fitness landscapes

Many real-world applications require decision-makers to assess the quality of solutions while considering multiple conflicting objectives. Obtaining good approximation sets for highly constrained many objective problems is often a difficult task even for modern multiobjective algorithms. In some cases, multiple instances of the problem scenario present similarities in their fitness landscapes. That is, there are recurring features in the fitness landscapes when searching for solutions to different problem instances. We propose a methodology to exploit this characteristic by solving one instance of a given problem scenario using computationally expensive multiobjective algorithms to obtain a good approximation set and then using Goal Programming with efficient single-objective algorithms to solve other instances of the same problem scenario. We use three goal-based objective functions and show that on benchmark instances of the multiobjective vehicle routing problem with time windows, the methodology is able to produce good results in short computation time. The methodology allows to combine the effectiveness of state-of-the-art multiobjective algorithms with the efficiency of goal programming to find good compromise solutions in problem scenarios where instances have similar fitness landscapes

The use of a direct manufacturing prosthetic socket system in a rural community in South Africa: a pilot study and lessons for future research

BACKGROUND: Challenges exist with the provision of appropriate mobility assistive devices in rural areas. The use of the direct manufacturing prosthetic socket system is a possible solution to these challenges. OBJECTIVES: The objective of this study was to test and explore the clients’ perspectives with the application of this device. Study design: Within a mixed-methods approach, a longitudinal sequential explanatory design was applied. METHODS: The Orthotic and Prosthetic User’s Survey was administered to explore the use of the direct manufacturing prosthetic socket system in terms of function, health-related quality of life and client satisfaction. A conveniently selected sample of 21 individuals who suffered a unilateral trans-tibial amputation was included. Data were collected at 1, 3 and 6 months post fitting, and two focus group discussions were also administered. RESULTS: Of the 21 participants recruited, 11 returned for follow up. Although participants reported favourably about the prosthesis, their scores were generally worse than the norms with regard to function and quality of life. Participants highlighted the need for improvement in the cosmetic appearance of the prosthesis. CONCLUSION: The direct manufacturing prosthetic socket system could be considered as an alternative technique of socket manufacturing for individuals living in rural areas due to the shorter manufacture time and promising initial results, but further research on this topic with a bigger sample is recommended.ISI & Scopu

A hyper-heuristic with two guidance indicators for bi-objective mixed-shift vehicle routing problem with time windows

In this paper, a Mixed-Shift Vehicle Routing Problem is proposed based on a real-life container transportation problem. In a long planning horizon of multiple shifts, transport tasks are completed satisfying the time constraints. Due to the different travel distances and time of tasks, there are two types of shifts (long shift and short shift) in this problem. The unit driver cost for long shifts is higher than that of short shifts. A mathematical model of this Mixed-Shift Vehicle Routing Problem with Time Windows (MS-VRPTW) is established in this paper, with two objectives of minimizing the total driver payment and the total travel distance. Due to the large scale and nonlinear constraints, the exact search showed is not suitable to MS-VRPTW. An initial solution construction heuristic (EBIH) and a selective perturbation Hyper-Heuristic (GIHH) are thus developed. In GIHH, five heuristics with different extents of perturbation at the low level are adaptively selected by a high level selection scheme with the Hill Climbing acceptance criterion. Two guidance indicators are devised at the high level to adaptively adjust the selection of the low level heuristics for this bi-objective problem. The two indicators estimate the objective value improvement and the improvement direction over the Pareto Front, respectively. To evaluate the generality of the proposed algorithms, a set of benchmark instances with various features is extracted from real-life historical datasets. The experiment results show that GIHH significantly improves the quality of the final Pareto Solution Set, outperforming the state-of-the-art algorithms for similar problems. Its application on VRPTW also obtains promising results

A MULTI-OBJECTIVE TRAIN SCHEDULING MODEL AND SOLUTION

Train scheduling is a highly complex task, since the physical railroad network is shared by a large number of both freight and passenger trains. This study develops a multi-objective optimization model for the passenger train-scheduling problem on a railroad network that includes single and multiple-tracks, as well as multiple platforms with different train capacities. In this study, lowering the fuel consumption cost is used as the measure of satisfaction of the railroad company and shortening the total passenger-time is being regarded as the passenger satisfaction criterion. The solution of the problem consists of two steps. To solve the problem, the Pareto frontier first is determined. Based on the obtained Pareto frontier, detailed multi-objective optimization then is performed using the distance-based method with three types of distances. A simple numerical example is given to illustrate the model, solution method and results. The sensitivity of the solutions was also examined. To demonstrate the applicability of the model and solution procedure, the results from 21 worked numerical examples are given