DYNAMIC RIDESHARE OPTIMIZED MATCHING PROBLEM

This dissertation develops a Dynamic Rideshare Optimized Matching (DROM) model and solution that is aimed at identifying suitable matches between passengers requesting rideshare services with appropriate drivers available to carpool for credits and HOV lane privileges. DROM receives passengers and drivers' information and preferences continuously over time and maximizes the overall system performance subject to ride availability, capacity, rider and driver time window constraints, and detour and relocation distances while considering users' preferences. The research develops a spatial, temporal, and hierarchical decomposition solution strategy that leads to the heuristic solution procedure. Three-Spherical Heuristic Decomposition Model (TSHDM). Quality and validity tests for the TSHDM algorithm are done by comparison of results between the exact and implemented algorithm solutions and major sensitivity analyses using the technique of Regression Analysis on all of the related parameters in the model are conducted to thoroughly investigate the properties of the proposed model and solution algorithm. A case study is constructed to analyze the model and TSHDM behaviors on a road network of northwest metropolitan area of Baltimore city. The study shows that however DROM is a very complicated and challenging problem from both mathematical formulation and solution algorithm perspectives, it is possible to implement a dynamic rideshare system using appropriate technical tools and social networking media. Major sensitivity analysis conducted on several parameters and variables affecting the model shows that most influencing factors for the rate of success in the rideshare system are, in order of importance: number of participating drivers, number of stops, area size, and number of participating riders. The study also shows rate of success for the rideshare system is highly dependent to the matched routes connecting directly points of origin and destination for participating riders and also increasing the number of connections from one to two which requires two consecutive change of rides for a rider has the least impact on the rate of success

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/

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

Assessment of localized pain sensitivity over the transtibial residual limb and its variability among male veterans with amputation

Localization of pain sensitization has clinical importance, however, rarely been assessed in amputees. The objective of this study was to investigate the sensitivity of pain over the residual limb and its variability among veterans with transtibial amputation. Pain sensitivity in 12 locations was explored twice in 19 veteran amputees using pressure algometry. The lowest pressure pain threshold (PPT) and pressure tolerance (PT) was recorded at the distal end of the residual limb (20.5 and 33 Ncm⁻², p=0.13), and the highest PPT and PT was recorded at the mid-patellar tendon (73.4 and 94.3 Ncm⁻², p=0.03). There was a significant moderate correlation (r=0.48-0.52) between pressure pain and daily hours of prosthesis use. A localized pattern for sensitivity to pain over the transtibial residual limb was obtained that can be used to improve the transtibial socket design and fit as well as the selection of prevention, evaluation, and treatment methods

Evaluation of Results and Patients’ Satisfaction of Alar Base Resection Surgery after Rhinoplasty Operations in 15 Khordad Hospital

Background: Alar base surgery is one of the controversial issues in rhinoplasty. In this surgery the nasal base width and alar flaring is got smaller with some kind of procedures. One of these procedures is wedge resection of alar base. This procedure may accompany with either some dissatisfaction of scars and adverse effects or complications. In this study, we evaluate the patient satisfaction of scar and possible complications.Materials and Methods: A total of 120 rhinoplasty patients at 15 khordad hospital were candidates for alar base wedge resection due to broad nasal base and / or alar flaring who were chosen for this study. We recorded and examined these patients before and minimum 6 months after surgery, then evaluated these information and data, which finally, compared all the preoperation and postoperation findings.Results: Mean age of patients was 30.11 years old. The full satisfaction of scar was 85.5% (103), but 6.7% (8) of patients had not satisfaction of scar due to visible scar in their alar facial groove. The rate of nostril symmetry satisfaction was 79.2% (95) and 8.3% (10) was dissatisfied due to nostril asymmetry. There was no external valve incompetency nor alar and sill notching in our study. There was not any narrowing of nostrils as well. The mean interalar distance preoperatively was 35.88 mm, which reduced to 32.61mm of mean diameter after surgery, (P-value = 0.000). Alar flaring correction was 88% (106) which was an acceptable consequence.Conclusion: The results of present study showed that in spite of surgeons fear for scar and some common complications after alar base resection, the satisfaction rate of our patients in this study were high, and complications frequencies were low. Therefore, we advise that it is better and wiser to do this operation in indicated patients surely within primary rhinoplasty and do not postpone it to another surgery

Long-term locked knee ankle foot orthosis use: A perspective overview of iatrogenic biomechanical and physiological perils

A knee ankle foot orthosis (KAFO) may be prescribed to the person with severe neuromusculoskeletal impairment of the lower limb to promote walking stability. The locked knee ankle foot orthosis (L-KAFO) is among the KAFO's routinely prescribed; however, long-term use of the L-KAFO is associated with musculoskeletal (arthrogenic and myogenic) and integumentary changes, and gait asymmetry with increased energy expenditure. Consequently, the risk of developing low back pain, osteoarthritis of the lower limbs and spinal joints, skin dermatitis, and ulceration increases, all of which impact quality of life. This article synthesizes the iatrogenic biomechanical and physiological perils of long-term L-KAFO use. It promotes using recent advances in rehabilitation engineering to improve daily activities and independence for proper patient groups

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/

The Effect of Perioperative Dimethyl Sulfoxide Efficacy on Regional and Local Flaps Viability

Background: The purpose of this study was to analyze the effects and results of dimethyl sulfoxide (DMSO) usage on viability and perfusion of local and regional flaps in rabbits, via this study we are going to conclude whether DMSO could be effective after flap operations in human or not. Materials and Methods: Local and regional DMSO spray was used on rabbit’s dorsum flaps immediately after the operation and once per day up to 7 days post-op in 14 rabbits, divided equally to control group (saline solution spray) or experiment group (DMSO spray). The results were compared 3 and 7 days after operations. Results: There were improved results attributed to the DMSO effects regarding flap survival Conclusion: We concluded that topical application of DMSO reduces skin flap ischemia in rabbits and we highly advise the use of it after operations in which skin flaps are created

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

A pin-array method for capturing tissue deformation under defined pressure distributions and its application to prosthetic socket design

The Fit4Purpose project aims to develop upper limb prosthetic devices which are suitable for deployment in lower- and middle-income countries (LMIC's). Open-frame trans-radial socket designs are being considered, formed of several, linked components, including pads which interface directly with the skin surface. A mechanical tool has been developed to aid the design of pad shapes, using an array of square brass bars of varying lengths (i.e. a pin-array) to apply a chosen normal pressure distribution to an area of tissue. The shape to which the tissue is displaced can then be captured by clamping the bars together to fix their relative positions. The device is described, then three short studies are used to demonstrate its use on the forearm of a single, anatomically intact subject. The first investigates the effect of array size on the measured surface stiffness, finding an inverse relationship with a similar characteristic to previous published results. The second tests the hypothesis that a pad with a shape which duplicates that captured by the device will generate a similar overall load to the original pins if applied to the same region of tissue. The results support the hypothesis, but also highlight the sensitivity of the interface loading to the underlying muscle activation. Finally, the tool is used to demonstrate that different tissue displacements are observed when the same pressure distribution is applied to different areas of the forearm. Whilst the tool itself is a simple device, and the techniques used are not sophisticated, the studies suggest that the approach could be useful in pad design. Although it is clearly not appropriate for clinical application in its current form, there may be potential to develop the concept into a more practical device. Other applications could include the design of other devices which interface with the skin, the generation of data for validation of finite element models, including the application of known pressure distributions and tissue deformations during Magnetic Resonance Imaging, and the assessment of matrix pressure sensing devices on compliant materials with complex geometries