scholarly journals A Scoping Review of Pressure Measurements in Prosthetic Sockets of Transfemoral Amputees during Ambulation: Key Considerations for Sensor Design

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5016
Author(s):  
Siu-Teing Ko ◽  
Fredrik Asplund ◽  
Begum Zeybek
Keyword(s):  
Scoping Review ◽  
Domain Knowledge ◽  
Experimental Studies ◽  
Pressure Sensors ◽  
Patient Comfort ◽  
Sensor Design ◽  
Sensor Systems ◽  
Data Generation ◽  
Prosthetic Socket ◽  
Transfemoral Amputees

Sensor systems to measure pressure at the stump–socket interface of transfemoral amputees are receiving increasing attention as they allow monitoring to evaluate patient comfort and socket fit. However, transfemoral amputees have many unique characteristics, and it is unclear whether existing research on sensor systems take these sufficiently into account or if it is conducted in ways likely to lead to substantial breakthroughs. This investigation addresses these concerns through a scoping review to profile research regarding sensors in transfemoral sockets with the aim of advancing and improving prosthetic socket design, comfort and fit for transfemoral amputees. Publications found from searching four scientific databases were screened, and 17 papers were found relating to the aim of this review. After quality assessment, 12 articles were finally selected for analysis. Three main contributions are provided: a de facto methodology for experimental studies on the implications of intra-socket pressure sensor use for transfemoral amputees; the suggestion that associated sensor design breakthroughs would be more likely if pressure sensors were developed in close combination with other types of sensors and in closer cooperation with those in possession of an in-depth domain knowledge in prosthetics; and that this research would be facilitated by increased interdisciplinary cooperation and open research data generation.

scholarly journals Magnetoactive elastomers for magnetically tunable vibrating sensor systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tatiana I. Becker ◽  
Yuriy L. Raikher ◽  
Oleg V. Stolbov ◽  
Valter Böhm ◽  
Klaus Zimmermann
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Smart Materials ◽  
Excitation Frequency ◽  
Experimental Studies ◽  
Uniform Field ◽  
Sensor Systems ◽  
Ongoing Research ◽  
Amplification Ratio ◽  
Field Distortion

Abstract Magnetoactive elastomers (MAEs) are a special type of smart materials consisting of an elastic matrix with embedded microsized particles that are made of ferromagnetic materials with high or low coercivity. Due to their composition, such elastomers possess unique magnetic field-dependent material properties. The present paper compiles the results of investigations on MAEs towards an approach of their potential application as vibrating sensor elements with adaptable sensitivity. Starting with the model-based and experimental studies of the free vibrational behavior displayed by cantilevers made of MAEs, it is shown that the first bending eigenfrequency of the cantilevers depends strongly on the strength of an applied uniform magnetic field. The investigations of the forced vibration response of MAE beams subjected to in-plane kinematic excitation confirm the possibility of active magnetic control of the amplitude-frequency characteristics. With change of the uniform field strength, the MAE beam reveals different steady-state responses for the same excitation, and the resonance may occur at various ranges of the excitation frequency. Nonlinear dependencies of the amplification ratio on the excitation frequency are obtained for different magnitudes of the applied field. Furthermore, it is shown that the steady-state vibrations of MAE beams can be detected based on the magnetic field distortion. The field difference, which is measured simultaneously on the sides of a vibrating MAE beam, provides a signal with the same frequency as the excitation and an amplitude proportional to the amplitude of resulting vibrations. The presented prototype of the MAE-based vibrating unit with the field-controlled “configuration” can be implemented for realization of acceleration sensor systems with adaptable sensitivity. The ongoing research on MAEs is oriented to the use of other geometrical forms along with beams, e.g. two-dimensional structures such as membranes.

scholarly journals A low-cost, human-like, high-resolution, tactile sensor based on optical fibers and an image sensor

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878363 ◽  
Author(s):  
Utku Büyükşahin ◽  
Ahmet Kırlı
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Fiber Optic ◽  
Low Cost ◽  
Experimental Studies ◽  
Main Idea ◽  
Tactile Sensor ◽  
Image Sensor ◽  
Sensor Design ◽  
Tactile Sensors

Tactile sensors are commonly a coordinated group of receptors forming a matrix array meant to measure force or pressure similar to the human skin. Optic-based tactile sensors are flexible, sensitive, and fast; however, the human fingertip’s spatial resolution, which can be regarded as the desired spatial resolution, still could not be reached because of their bulky nature. This article proposes a novel and patented optic-based tactile sensor design, in which fiber optic cables are used to increase the number of sensory receptors per square centimeter. The proposed human-like high-resolution tactile sensor design is based on simple optics and image processing techniques, and it enables high spatial resolution and easy data acquisition at low cost. This design proposes using the change in the intesity of the light occured due to the deformation on contact/measurement surface. The main idea is using fiber optic cables as the afferents of the human physiology which can have 9 µm diameters for both delivering and receiving light beams. The variation of the light intensity enters sequent mathematical models as the input, then, the displacement, the force, and the pressure data are evaluated as the outputs. A prototype tactile sensor is manufactured with 1-mm spatial and 0.61-kPa pressure measurement resolution with 0–15.6 N/cm2 at 30 Hz sampling frequency. Experimental studies with different scenarios are conducted to demonstrate how this state-of-the-art design worked and to evaluate its performance. The overall accuracy of the first prototype, based on different scenarios, is calculated as 93%. This performance is regarded as promising for further developments and applications such as grasp control or haptics.

scholarly journals Within-subjects Effects of Standardized Prosthetic Socket Modifications on Physical Function and Patient-Reported Outcomes

2021 ◽  
Author(s):  
William Anderst ◽  
Goeran Fiedler ◽  
Kentaro Onishi ◽  
Gina McKernan ◽  
Tom Gale ◽  
...  
Keyword(s):  
Physical Function ◽  
Patient Reported Outcomes ◽  
Design Method ◽  
Pressure Sensors ◽  
Residual Limb ◽  
Prosthetic Socket ◽  
Large Patient ◽  
Increased Risk ◽  
Patient Reported ◽  
And Function

Abstract • Background: Among the challenges of living with lower limb loss is the increased risk of long-term health problems that can be either attributed directly to the amputation surgery and/or prosthetic rehabilitation or indirectly to a disability-induced sedentary lifestyle. These problems are exacerbated by poorly fit prosthetic sockets. There is a knowledge gap regarding how the socket design affects in-socket mechanics, and how in-socket mechanics affect patient-reported comfort and function. The objectives of this study are: 1) to gain a better understanding of how in-socket mechanics of the residual limb in transfemoral amputees are related to patient-reported comfort and function, 2) to identify clinical tests that can streamline the socket design process, and 3) to evaluate the efficacy and cost of a novel, quantitatively informed socket optimization process.• Methods: Users of transfemoral prostheses will be asked to walk on a treadmill wearing their current socket plus 8 different check sockets with designed changes in different structural measurements that are likely to induce changes in residual limb motion, skin strain, and pressure distribution within the socket. Dynamic biplane radiography and pressure sensors will be used to measure in-socket residual limb mechanics. Patient-reported outcomes will also be collected after wearing each socket. The effects of in-socket mechanics on both physical function and patient-reported outcomes (aim 1) will be assessed using a generalized linear model. Partial correlation analysis will be used to examine the association between research grade measurements and readily available clinical measurements (aim 2). In order to compare the new quantitative design method to the Standard of Care, patient reported outcomes and cost will be compared between the two methods, utilizing the Wilcoxon Mann-Whitney non-parametric test (aim 3).• Discussion: Knowledge on how prosthetic socket modifications affect residual bone and skin biomechanics itself can be applied to devise future socket designs, and the methodology can be used to investigate and improve such designs, past and present. Apart from saving time and costs, this may result in better prosthetic socket fit for a large patient population, thus increasing their mobility, participation, and overall health-related quality of life. • Trial registration: clinicaltrials.gov: NCT05041998

Method of metrological self-checking of a strain gauge pressure sensor

Metrologiya ◽  
2020 ◽  
pp. 48-62
Author(s):  
Vladimir A. Larionov
Keyword(s):  
Strain Gauge ◽  
Supply Voltage ◽  
Experimental Studies ◽  
Pressure Sensors ◽  
Experimental Sample ◽  
Self Monitoring ◽  
Gauge Pressure ◽  
External Conditions ◽  
Temperature And Pressure ◽  
Overall Resistance

Existing methods of metrological self-monitoring of measuring sensors for temperature and pressure of technological industries are considered. The analysis of methods of metrological self-checking of strain gauge pressure sensors is carried out. Method is proposed based on measuring the supply voltage and voltage on the measuring diagonal of the bridge. The temperature of the strain gauge bridge is determined using a semiconductor thermistor installed near the bridge. This allows you to adjust the measured value of the total resistance of the bridge from the temperature of the bridge. With aging and exposure to external conditions, a change in the overall resistance of the bridge can be used to judge the error of the sensor. An experimental sample of the sensor was made. The failure of the strain gage bridge is simulated by parallel connection of an additional resistor to one of the shoulders of the bridge. Experimental studies have shown that modern technical means make it possible to assess the effect of changes in the total bridge resistance on the sensor error.

Psychosocial Depression Interventions for Dialysis Patients, With Attention to Latinos: A Scoping Review

2019 ◽  
Vol 29 (8) ◽  
pp. 910-923 ◽  
Author(s):  
John E. Sullivan ◽  
Namkee G. Choi ◽  
Christian E. Vazquez ◽  
Margaret A. Neaves
Keyword(s):  
Scoping Review ◽  
Expressive Writing ◽  
Behavioral Therapy ◽  
Grey Literature ◽  
Behavioral Problem ◽  
Experimental Studies ◽  
The United States ◽  
Cognitive Behavioral ◽  
Dialysis Patients ◽  
Quasi Experimental

Purpose: Depression is a common and debilitating condition that often goes undetected and untreated among people with end-stage renal disease (ESRD). We conducted a scoping review to identify psychosocial depression interventions for adult dialysis patients and gaps in depression care, with particular attention to Latinos, a group disproportionately affected by ESRD in the United States. Methods: We searched electronic databases and grey literature sources for studies in English and Spanish. Results: We found 36 studies including cognitive behavioral, problem-solving, hope, psychoeducation, expressive writing, and physical activity interventions. Twelve studies (33%) were U.S.-based, while the rest were conducted elsewhere. U.S.-based studies involved mostly individual-format cognitive behavioral therapy (CBT) interventions carried out during dialysis. CBTs showed the most promising effect on depression in both randomized clinical and quasi-experimental studies. Among 22 randomized trials reviewed, 1 reported participants with Latino/Hispanic ethnicity. Conclusions: More intervention research is needed for depression treatment with ESRD patients, especially Latinos.

Microsensors for Automotive Applications – Metrology and Test

2001 ◽  
Vol 687 ◽  
Author(s):  
Gottfried Flik ◽  
Heinz Eisenschmid ◽  
Carsten Raudzis ◽  
Frank Schatz ◽  
Winfried Schoenenborn ◽  
...  
Keyword(s):  
Inertial Sensors ◽  
Pressure Sensors ◽  
Critical Parameters ◽  
Design For Test ◽  
Sensor Design ◽  
Wafer Level ◽  
Process Technology ◽  
Test Procedures ◽  
Silicon Bulk ◽  
Critical Model

AbstractAccording to market surveys automotive microsensors will evolve into a multi-billion dollar business by 2005. Key roles are attributed to inertial sensors for passenger safety systems, and mass flow and pressure sensors for engine management systems. Thin film techniques together with silicon bulk or surface micromachining have been established as preferential processes to achieve reduction of sensor size, weight and cost along with improvements of sensor functionality and reliability. Enhanced sensor performance often pushes the limits of process technology and therefore the need arises very early in the MEMS design process to identify materials and geometry related parameters which are critical with respect to their tolerance band specifications. In order to control these critical parameters, automated wafer level test procedures need to be developed (based preferentially on electrical quantities) and additionally considered for in the sensor design phase (design for test). In analogy to microelectronics 2D wafer maps of critical parameters may give hints on how to improve process stability and how to adapt the sensor design in order to optimize yield. Examples of critical model parameter variations include thermal conductivity, thickness, and shear modulus of thin films.

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