scholarly journals Towards Management of Residual Limb Volume: Monitoring the Prosthetic Interface Pressure to Detect Volume Fluctuations—A Feasibility Study

2020 ◽  
Vol 10 (19) ◽  
pp. 6841
Author(s):  
Chakaveh Ahmadizadeh ◽  
Brittany Pousett ◽  
Carlo Menon
Keyword(s):  
Feedback System ◽  
Second Phase ◽  
Residual Limb ◽  
Interface Pressure ◽  
Limb Volume ◽  
Prosthetic Socket ◽  
Phase Variations ◽  
Distal Location ◽  
Second Phases ◽  
Two Phases

(1) Motivation: Variations in the volume of the residual limb negatively impact various aspects of prosthesis use including the prosthetic socket fit. Although volume adjustment systems mitigate corresponding fit problems to some extent, some users still find the management of these systems challenging. With the ultimate goal of creating a feedback system that assists users with the management of their volume adjustment systems, this study demonstrates the feasibility of detecting variations in the volume of the residual limb. (2) Methods: Measurements of the interface force at the bottom of the prosthetic socket were used as indicators of variations in the volume of the residual limb. Force sensitive resistors (FSRs) were placed at the bottom of participants’ prosthetic sockets to monitor the interface limb–socket force as participants walked on a flat surface. Two phases of experiments were carried out: The first phase considered variations simulated by three prosthetic sock plies, established the feasibility of detecting variations in the volume of the limb based on the interface force, and further determined the locations at which the interface force could be used to detect variations in the limb’s volume. Having validated the effectiveness of the proposed method in the first phase, the second phase was carried out to determine the smallest detectable variation of the limb’s volume using the proposed method. In this phase, variations simulated by one and two prosthetic sock plies were considered. Four and three volunteers with transtibial amputations participated in the first and the second phases, respectively. (3) Results: Results of the first phase showed that an increase in the volume of the limb resulted in a decrease in the force measured at the distal location of the prosthetic sockets of all participants; however, the smallest detected variation could not be statistically confirmed.

Three-dimensional printing in prosthetics: Method for managing rapid limb volume change

2020 ◽  
Vol 44 (5) ◽  
pp. 355-358 ◽  
Author(s):  
Eric Nickel ◽  
Kyle Barrons ◽  
Barry Hand ◽  
Alana Cataldo ◽  
Andrew Hansen
Keyword(s):  
Service Life ◽  
Three Dimensional ◽  
Residual Limb ◽  
Volume Loss ◽  
Limb Volume ◽  
Three Dimensional Printing ◽  
Body Mass Change ◽  
Prosthetic Socket ◽  
Test Distance ◽  
Gain Loss

Background and Aim: During post-amputation recovery or rapid body mass change, residual limb volume can change quickly, requiring frequent adjustments or replacement of the socket to maintain fit. The aim of this pilot test was to evaluate the feasibility of using a three-dimensional-printed insert to extend the service life of a prosthetic socket after substantial residual limb volume loss. Technique: One research subject with a well-fitting transtibial prosthetic socket had an oversized socket fabricated to simulate substantial limb volume loss. The digital shapes of the oversized and well-fitting sockets were used to create a three-dimensional-printed insert to restore fit. Discussion: Two-minute walk test distance decreased when using the oversized socket without the insert, but not when using the socket with the insert. Socket comfort score was 8+ under all conditions. These results suggest that three-dimensional-printed inserts may be an effective method of extending the service life of prosthetic sockets when rapid limb volume loss occurs. Clinical relevance Three-dimensional (3D) printing gives prosthetists a new tool to manage large volume changes without refabricating entire sockets. Sockets can be fabricated in anticipation of volume gain/loss, using replaceable 3D-printed inserts to maintain fit and comfort.

Fluctuating residual limb volume accommodated with an adjustable, modular socket design: A novel case report

2016 ◽  
Vol 41 (5) ◽  
pp. 527-531 ◽  
Author(s):  
Kay Mitton ◽  
Jai Kulkarni ◽  
Kenneth William Dunn ◽  
Anthony Hoang Ung
Keyword(s):  
Case Report ◽  
Complex Regional Pain Syndrome ◽  
Patellofemoral Instability ◽  
Pain Syndrome ◽  
Successful Outcome ◽  
Residual Limb ◽  
Case Description ◽  
Limb Volume ◽  
Prosthetic Socket ◽  
Volume Fluctuations

Background: This novel case report describes the problems of prescribing a prosthetic socket in a left transfemoral amputee secondary to chronic patellofemoral instability compounded by complex regional pain syndrome. Case Description and Methods: Following the amputation, complex regional pain syndrome symptoms recurred in the residual limb, presenting mainly with oedema. Due to extreme daily volume fluctuations of the residual limb, a conventional, laminated thermoplastic socket fitting was not feasible. Findings and Outcomes: An adjustable, modular socket design was trialled. The residual limb volume fluctuations were accommodated within the socket. Amputee rehabilitation could be continued, and the rehabilitation goals were achieved. The patient was able to wear the prosthesis for 8 h daily and to walk unaided indoors and outdoors. Conclusion: An adjustable, modular socket design accommodated the daily residual limb volume fluctuations and provided a successful outcome in this case. It demonstrates the complexities of socket fitting and design with volume fluctuations. Clinical relevance Ongoing complex regional pain syndrome symptoms within the residual limb can lead to fitting difficulties in a conventional, laminated thermoplastic socket due to volume fluctuations. An adjustable, modular socket design can accommodate this and provide a successful outcome.

scholarly journals Self-reported prosthetic sock use among persons with transtibial amputation

2013 ◽  
Vol 38 (4) ◽  
pp. 321-331 ◽  
Author(s):  
Krittika D’Silva ◽  
Brian J Hafner ◽  
Katheryn J Allyn ◽  
Joan E Sanders
Keyword(s):  
Management Strategies ◽  
Limb Loss ◽  
Self Report ◽  
Diurnal Changes ◽  
Residual Limb ◽  
Limb Volume ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Transtibial Amputation ◽  
Prosthetic Socket

Background: Daily changes in the shape and size of the residual limb affect prosthetic socket fit. Prosthetic socks are often added or removed to manage changes in limb volume. Little has been published about how persons with transtibial amputations use socks to manage diurnal changes in volume and comfort. Objectives: To investigate prosthetic sock use with a customized, self-report questionnaire. Study design: Cross-sectional survey. Methods: Persons with transtibial amputation reported number, thickness, and timing of socks used over a 14-day period. Results: Data from 23 subjects (16 males and 7 females) were included. On average, socks were changed less than once per day (0.6/day) and ply increased over the day (4.8–5.5 ply). Subjects wore prostheses significantly longer (15.0–14.1 h, p = 0.02) and changed socks significantly more often (0.6/day–0.4/day, p = 0.03) on weekdays compared to weekends. Participants were also divided into two subgroups: those who used socks to manage limb volume and those who used socks for socket comfort. Sock use did not differ (p > 0.05) between subgroups. Conclusions: Sock changes are infrequent among persons with lower limb loss. Initial, verbal reports of sock use were often inconsistent with data measured by logs. Tools (e.g. sock logs or objective instruments) to better understand sock-use habits among persons with limb loss are needed. Clinical relevance Knowledge of prosthetic patients’ sock use may help practitioners enhance volume management strategies or troubleshoot fitting issues. Results showed that subjects generally added socks to account for volume loss, and end-of-day sock thickness frequently exceeded 5 ply. Use of sock logs in clinical practice may facilitate improved residual limb health.

Clinical utility of pressure feedback to socket design and fabrication

2019 ◽  
Vol 44 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Lucy Armitage ◽  
Angela Buller ◽  
Ginu Rajan ◽  
Gangadhara Prusty ◽  
Anne Simmons ◽  
...  
Keyword(s):  
Clinical Utility ◽  
Repeated Measurements ◽  
Fabrication Process ◽  
Anatomical Landmarks ◽  
Residual Limb ◽  
Pressure Measurements ◽  
Interface Pressure ◽  
Prosthetic Socket ◽  
New Information ◽  
Pressure Feedback

Background: The clinical utility of measuring pressure at the prosthetic socket-residual limb interface is currently unknown. Objectives: This study aimed to identify whether measuring interface pressure during prosthetic design and fabrication results in closer agreement in pressure measurements between sockets made by different clinicians, and a reduction in pressure over areas of concern. It also investigated whether clinicians value knowing the interface pressure during the fabrication process. Study design: Mixed methods. Methods: Three prosthetists designed a complete prosthetic system for a transtibial residual limb surrogate. Standardised mechanical testing was performed on each prosthetic system to gain pressure measurements at four key anatomical locations. These measurements were provided to the clinicians, who subsequently modified their sockets as each saw fit. The pressure at each location was re-measured. Each prosthetist completed a survey that evaluated the usefulness of knowing interface pressures during the fabrication process. Results: Feedback and subsequent socket modifications saw a reduction in the pressure measurements at three of the four anatomical locations. Furthermore, the pressure measurements between prosthetists converged. All three prosthetists found value in the pressure measurement system and felt they would use it clinically. Conclusions: Results suggest that sensors measuring pressure at the socket-limb interface has clinical utility in the context of informing prosthetic socket design and fabrication. If the technology is used at the check socket stage, iterative designs with repeated measurements can result in increased consistency between clinicians for the same residual limb, and reductions in the magnitudes of pressures over specific anatomical landmarks. Clinical relevance This study provides new information on the value of pressure feedback to the prosthetic socket design process. It shows that with feedback, socket modifications can result in reduced limb pressures, and more consistent pressure distributions between prosthetists. It also justifies the use of pressure feedback in informing clinical decisions.

scholarly journals Design of an Actuated Volume Compensating SLS Prosthetic Socket

2009 ◽  
Vol 3 (2) ◽  
Author(s):  
J. Montgomery ◽  
M. Vaughan ◽  
R. Crawford
Keyword(s):  
Tensile Strength ◽  
Apparent Density ◽  
Activity Level ◽  
Energy Concentration ◽  
Residual Limb ◽  
Concept Generation ◽  
Limb Volume ◽  
Testing Specimen ◽  
Prosthetic Socket ◽  
Flexible Material

Studies have shown residual limb volume can vary −11% to 7% in a single day due to changing activity level or weight. However, volume changes of only 3% to 5% can cause users to have difficulty putting on their prosthetic socket. Many existing volume compensation methods are cumbersome, rely on the amputee to maintain the appropriate pressure level, or allow only for a decrease in limb volume. Automatic compensation for volume gain and loss is therefore needed; however, the complexity of designing such sockets renders a traditional fabrication methods cost prohibitive or technically infeasible. Selective Laser Sintering (SLS), a rapid manufacturing (RM) technology, addresses both of these concerns. SLS is a layer-based RM technology that relies on a high power laser to fuse powder particles into a solid object. Minute detail, directly from a 3D CAD model, is possible and a technique has been established for manufacturing prosthetic sockets with passive compliant regions using SLS. Based on this SLS RM technique, steps toward developing a transtibial Nylon prosthetic socket that automatically adapts to volumetric changes in a residual limb will be described. A design methodology was developed to use RM including concept generation, refinement, and final verification. In concept generation, analogies, such as “Chinese Fingertraps” and balloons, were coupled with a review of socket designs in literature and industry and interviews with prosthetists. Inflation of a bladder integrated into the wall of a SLS socket is one of the promising design concepts generated, but the concept needs further refinement. In order to confidently design an inflatable SLS prosthetic, it is critical to understand the relationship between applied pressure and deflection. A testing specimen—5.08 cm diameter thinwalled membrane—was designed to simulate a bladder integrated into the wall of a SLS socket. Several thicknesses were also used to investigate the effects of this parameter on inflation. Preliminary tests were conducted using compressed air for quantifying pressure vs. displacement. During the tests, leakage through open porosity (due to low density) was detected. Density is strongly related to energy transmitted to the part during sintering. The energy concentration is quantified as the Andrew's Number (AN), the inverse relationship of laser power (LP) to laser scanning speed (SSP) and scan spacing (SS). Therefore, to determine the optimal AN—and therefore increase density—an experiment varying LP and SS (SSP is a manufacturer setting) to determine their effects on apparent density and tensile strength was completed. The optimal AN, 1.63 J/cm2 for Nylon 12 powder, was based on highest apparent density and tensile strength. Using this AN, additional deflection samples were tested. Initial results showed a maximum deflection of 2.1 mm at .145 MPa for a 1.3 mm thick membrane. In comparison, changing the volume of a 3D scan of a patient's residual limb by 6% in a 10.9 cm diameter region on the posterior distal tibia socket end, as recommended by a prosthetist, requires a 5.8 mm displacement. Therefore, early results suggest that a single bladder will not meet deflection requirements, influencing the design of multiple larger regions and use of a more flexible material. Results from these experiments will help eliminate concepts which cannot deflect the necessary amount for the volume change, further refining the concepts towards a solution.

scholarly journals Interface Pressure System to Compare the Functional Performance of Prosthetic Sockets during the Gait in People with Trans-Tibial Amputation

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7043
Author(s):  
Salvador Ibarra Aguila ◽  
Gisel J. Sánchez ◽  
Eric E. Sauvain ◽  
B. Alemon ◽  
Rita Q. Fuentes-Aguilar ◽  
...  
Keyword(s):  
Gait Cycle ◽  
Peak Pressure ◽  
Functional Performance ◽  
Physical Therapists ◽  
Residual Limb ◽  
Interface Pressure ◽  
Pressure System ◽  
Prosthetic Socket ◽  
Critical Regions ◽  
Socket Interface

The interface pressure between the residual limb and prosthetic socket has a significant effect on the amputee’s mobility and level of comfort with their prosthesis. This paper presents a socket interface pressure (SIFP) system to compare the interface pressure differences during gait between two different types of prosthetic sockets for a transtibial amputee. The system evaluates the interface pressure in six critical regions of interest (CROI) of the lower limb amputee and identifies the peak pressures during certain moments of the gait cycle. The six sensors were attached to the residual limb in the CROIs before the participant with transtibial amputation donned a prosthetic socket. The interface pressure was monitored and recorded while the participant walked on a treadmill for 10 min at 1.4 m/s. The results show peak pressure differences of almost 0.22 kgf/cm2 between the sockets. It was observed that the peak pressure occurred at 50% of the stance phase of the gait cycle. This SIFP system may be used by prosthetists, physical therapists, amputation care centers, and researchers, as well as government and private regulators requiring comparison and evaluation of prosthetic components, components under development, and testing.

scholarly journals Pressure Distribution Management System in 3D Printed Transtibial Prosthetic Socket during Static Loading: A Preliminary Assessment during Stance Phase

2020 ◽  
Author(s):  
Murad Abdullah Subih ◽  
Nooranida Arifin ◽  
Ebrahim Al-Fakih
Keyword(s):  
Control System ◽  
Management System ◽  
Stance Phase ◽  
Residual Limb ◽  
Pressure Reduction ◽  
Interface Pressure ◽  
Distribution Management ◽  
Prosthetic Socket ◽  
3D Printed ◽  
Distribution Management System

Abstract Background A management system within a prosthetic socket for efficient redistribution and interface pressure reduction is highly demanded. This research article developed a new control system for interface pressure in a 3D printed transtibial prosthetic socket. This system aimed to redistribute and reduce the high interface pressure along residual limb regions in a 3D printed socket. Methods A 3D printed socket was built with tiny air bladders that were integrated with the liner. This 3D socket had three air bladders located on the posterior, lateral, and medial sides, and connected to three separate mini pumps and valves for inflation and deflation. The air bladders' inflation and deflation were controlled by using a pre-programed keypad. The keypad with an electronic system (electronic circuit, mini pumps, and valves) was attached to a prosthetic pylon in a small box. A universal tensile machine was employed to apply loads into the prosthetic device to resemble human body weight. The interface pressure in the 3D printed socket was evaluated by using F- socket transducers at proximal, middle, and distal regions of an artificial residual limb during inflation and deflation of the air bladders in stance phase. Results The pressure control system minimized the interface pressures within the 3D printed prosthetic socket during inflation. The posterior and medial sides recorded a maximum reduction in pressure during the inflation of posterior and medial air bladders, respectively. Statistically, the highest significant pressure reduction (p < 0.05) was 6.81%, which was recorded at the posterior proximal subregion and 3.44% (p > 0.05) at the medial middle, but it was not significant. There was no statistical change in the mean pressure values at the whole anterior side, but there were significant differences during lateral and medial air bladder inflation and deflation. Conclusions This study is intended to recognize the impact of high interface pressure around the residual limb more deeply. The new pressure distribution management system offered rearrangement with minimized interface pressure over the artificial residual limb subregions.

Structure of second phases in TiAl alloys containing Cr and B

1991 ◽  
Vol 49 ◽  
pp. 576-577
Author(s):  
Ernest L. Hall ◽  
Shyh-Chin Huang
Keyword(s):  
Grain Size ◽  
Second Phase ◽  
Structure And Properties ◽  
Tial Alloys ◽  
Second Phases ◽  
Interstitial Elements

Addition of interstitial elements to γ-TiAl alloys is currently being explored as a method for improving the properties of these alloys. Previous work in which a number of interstitial elements were studied showed that boron was particularly effective in refining the grain size in castings, and led to enhanced strength while maintaining reasonable ductility. Other investigators have shown that B in γ-TiAl alloys tends to promote the formation of TiB2 as a second phase. In this study, the microstructure of Bcontaining TiAl alloys was examined in detail in order to describe the mechanism by which B alters the structure and properties of these alloys.

Accurate Detection and Quantization of Leaf- Diseases through Soft Computing

2018 ◽  
Vol 1 (1) ◽  
pp. 236-247
Author(s):  
Divya Srivastava ◽  
Rajitha B. ◽  
Suneeta Agarwal
Keyword(s):  
Machine Learning ◽  
Image Processing ◽  
Agricultural Production ◽  
Bacterial Blight ◽  
Early Stage ◽  
Second Phase ◽  
Computationally Efficient ◽  
Stage Of Disease ◽  
Accurate Detection ◽  
Two Phases

Diseases in leaves can cause the significant reduction in both quality and quantity of agricultural production. If early and accurate detection of disease/diseases in leaves can be automated, then the proper remedy can be taken timely. A simple and computationally efficient approach is presented in this paper for disease/diseases detection on leaves. Only detecting the disease is not beneficial without knowing the stage of disease thus the paper also determine the stage of disease/diseases by quantizing the affected of the leaves by using digital image processing and machine learning. Though there exists a variety of diseases on leaves, but the bacterial and fungal spots (Early Scorch, Late Scorch, and Leaf Spot) are the most prominent diseases found on leaves. Keeping this in mind the paper deals with the detection of Bacterial Blight and Fungal Spot both at an early stage (Early Scorch) and late stage (Late Scorch) on the variety of leaves. The proposed approach is divided into two phases, in the first phase, it identifies one or more disease/diseases existing on leaves. In the second phase, amount of area affected by the disease/diseases is calculated. The experimental results obtained showed 97% accuracy using the proposed approach.

Representação e simbolismo: artes visuais na fronteira Brasil/Bolívia

2020 ◽  
Vol 4 (3) ◽  
pp. 286
Author(s):  
Paulo César Antonini de Souza ◽  
Derick Trindade Bezerra
Keyword(s):  
Visual Arts ◽  
Social Order ◽  
Research Field ◽  
Border Region ◽  
Second Phase ◽  
Two Dimensional ◽  
Santa Cruz ◽  
Cultural Conditions ◽  
Two Phases ◽  
America Latina

ResumoTendo por campo de investigação o Festival da América do Sul Pantanal (FASP) em 2018, na cidade de Corumbá (Brasil), objetiva-se identificar a materialidade e conceitos que permeiam as manifestações artísticas bidimensionais nesta região de fronteira, a partir da percepção de artistas da Bolívia. A pesquisa se organizou em duas fases: na primeira foi realizado um levantamento em plataformas online de produções acadêmicas em artes visuais, com foco no trabalho bidimensional, utilizando os descritores “arte popular” e “estética latina” resultando em três artigos. Na segunda fase foram selecionados dois trabalhos de uma artista da Bolívia, participante da mostra “Conexão Santa Cruz”, realizada durante o FASP 2018, que foram analisados em seus níveis representacional e simbólico. Pela interpretação das imagens foi possível construir uma leitura sobre a perspectiva da artista a respeito de suas condições culturais dentro da ordenação social em que se encontra situada.Palavras-chave: Artes Visuais. Arte Popular. Arte Regional. América Latina. Representation and symbolism: visual arts on the Brazil/Bolivia frontierAbstractHaving as research field the Festival da América do Sul Pantanal (FASP) in 2018, in the city of Corumbá (Brazil), the objective is to identify the materiality and concepts that permeate the two-dimensional artistic manifestations in this border region, from the perception of artists from Bolivia. The research was organized in two phases: in the first, a survey was carried out on online platforms of academic productions in visual arts, focusing on two-dimensional work, using the descriptors “arte popular” and “estética latina” resulting in three articles. In the second phase, two works were selected by an artist from Bolivia, participating in the exhibition “Conexão Santa Cruz”, held during FASP 2018, which were analyzed at their representational and symbolic levels. Through the interpretation of the images, it was possible to construct a reading on the artist’s perspective regarding her cultural conditions within the social order in which she is located.Keywords: Visual Arts. Folk Art. Regional Art. Latin America.Representación y simbolismo: artes visuales en la frontera de Brasil/BoliviaResumenTeniendo como campo de investigación el Festival de Sudamérica Pantanal (FASP) en 2018, en la ciudad de Corumbá (Brasil), el objetivo es identificar la materialidad y conceptos que permean las manifestaciones artísticas bidimensionales en esta región fronteriza, desde la percepción de artistas de Bolivia. La investigación se organizó en dos fases: en la primera, se realizó una encuesta en plataformas online de producciones académicas en artes visuales, con foco en el trabajo bidimensional, utilizando los descriptores “arte popular” y “estética latina” dando como resultado tres artículos. En la segunda fase, dos obras fueron seleccionadas por un artista de Bolivia, participante de la exposición “Conexão Santa Cruz”, realizada durante FASP 2018, que fueron analizadas en sus niveles representativos y simbólicos. A través de la interpretación de las imágenes, fue posible construir una lectura sobre la perspectiva de la artista sobre sus condiciones culturales dentro del orden social en el que se ubica.Palabras clave: Artes Visuales. Arte Popular. Arte Regional. América Latina.

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