scholarly journals INVESTIGATION OF LOCALIZED SKIN TEMPERATURE DISTRIBUTION ACROSS THE TRANSTIBIAL RESIDUAL LIMB

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Kamiar Ghoseiri ◽  
Mostafa Allami ◽  
Justin R. Murphy ◽  
Phillip Page ◽  
Duane C. Button
Keyword(s):  
Temperature Distribution ◽  
Skin Temperature ◽  
Clinical Characteristics ◽  
Arterial Blood Flow ◽  
Residual Limb ◽  
Medial Surface ◽  
Arterial Blood ◽  
Temperature Recording ◽  
Mean Temperature ◽  
The Mean

BACKGROUND: Interventions to resolve thermal discomfort as a common complaint in amputees are usually chosen based on the residual limb skin temperature while wearing prosthesis; whereas, less attention has been paid to residual limb skin temperature while outside of the prosthesis. The objective of this study was to explore the localized and regional skin temperature over the transtibial residual limb (TRL) while outside of the prosthesis. METHODOLOGY: Eight unilateral transtibial adults with traumatic amputation were enrolled in this cross-sectional study. Participants sat to remove their prostheses and rested for 30 minutes. Twelve sites were marked circumferentially in four columns (anterolateral, anteromedial, posteromedial, and posterolateral) and longitudinally in three rows (proximal, middle, and distal) over the residual limb and used for attachment of analog thermistors. Skin temperature was recorded and compared for 11 minutes. Furthermore, the relationship of skin temperature with participants’ demographic and clinical characteristics was explored. FINDINGS: The whole temperature of the TRL was 27.73 (SD=0.83)°C. There was a significant difference in skin temperature between anterior and posterior columns. Likewise, the distal row was significantly different from the proximal and middle rows. The mean temperature at the middle and distal zones of the anteromedial column had the highest and lowest skin temperatures (29.8 and 26.3°C, p<0.05), respectively. The mean temperature of the whole TRL had no significant relationships (p>0.05) with participants’ demographic and clinical characteristics. CONCLUSIONS: An unequal distribution of temperature over the TRL was found with significantly higher and lower temperatures at its anterior column and distal row, respectively. This temperature pattern should be considered for thermoregulation strategies. Further investigation of the residual limb temperature with and without prosthesis, while considering muscles thickness and blood perfusion rate is warranted. Layman's Abstract The socket is a plastic hard-shell interface between the residual limb, the remaining part of the amputated limb, and a prosthesis. Heat buildup inside the prosthetic socket and perspiration of the residual limb are major discomforts in amputees when wearing a prosthesis. The majority of prior research measured residual limb skin temperature while the prosthesis was worn. However, less attention has been paid to skin temperature without prostheses. Skin temperature of eight adults with one-sided traumatic below-knee amputation was measured. Participants sat and removed their prostheses. Twelve anatomical sites were marked circumferentially in four columns and longitudinally in three rows over the residual limb and used for temperature recording using temperature sensors. The whole temperature of the residual limb was 27.73 (SD=0.83)°C. Skin temperature was higher at anterior columns compared to posterior columns. Similarly, the distal row of the residual limb had the lowest temperature compared to its middle and proximal rows. From a localized standpoint, the middle part at the anterior medial surface of the residual limb had the highest temperature, whereas the distal part at the anterior-medial surface had the lowest skin temperature. There was no noticeable relationship between the average of the residual limb skin temperature and participants’ demographic and clinical characteristics. Some strategies need to be developed to regulate and control heat dissipation over the residual limb's surface when amputees do not wear prostheses. Further temperature recording research by considering muscle thickness and arterial blood flow rate of the residual limb with and without prosthesis is suggested. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/35070/27313 How To Cite: Ghoseiri K, Allami M, Murphy J.R, Page P, Button D.C. Investigation of localized skin temperature distribution across the transtibial residual limb. Canadian Prosthetics & Orthotics Journal. 2021;Volume 4, Issue 1, No.2. https://doi.org/10.33137/cpoj.v4i1.35070 Corresponding Author: Duane C Button, PhDSchool of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada.E-mail: [email protected]: https://orcid.org/0000-0001-6402-8545    

Analysis of Turbulent Thermal Convection Between Horizontal Plates

1983 ◽  
Vol 105 (4) ◽  
pp. 789-794 ◽  
Author(s):  
M. Kaviany ◽  
R. Seban
Keyword(s):  
Temperature Distribution ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Thermal Convection ◽  
Equation Model ◽  
Experimental Results ◽  
Mixing Length ◽  
Mean Temperature ◽  
The Mean ◽  
The One

The one-equation model of turbulence is applied to the turbulent thermal convection between horizontal plates maintained at constant temperatures. A pseudo-three-layer model is used consisting of a conduction sublayer adjacent to the plates, a turbulent region within which the mixing length increases linearly, and a turbulent core within which the mixing length is a constant. It is assumed that the Nusselt number varies with the Rayleigh number to the one-third power. As a result, the steady-state distributions of the turbulent kinetic energy and the mean temperature are obtrained and presented in closed forms. These results include the effects of Prandtl number. The predictions are compared with the available experimental results for different Prandtl and Rayleigh numbers. Also included are the predictions of Kraichnan, which are based on a less exact analysis. The results of the one-equation model are in fair agreement with the experimental results for the distribution of the turbulent kinetic energy and the mean temperature distribution. The predictions of Kraichnan are in better agreement with the experimental results for the mean temperature distribution.

scholarly journals Temporal Vascular Changes in Leg with Ulcer Due to Autonomic Neuropathy

2019 ◽  
Vol 28 (03) ◽  
pp. 167-172
Author(s):  
Behçet K. Ener ◽  
Handan Uçankale ◽  
Reyhan Sürmeli
Keyword(s):  
Blood Flow ◽  
Lower Extremity ◽  
Autonomic Neuropathy ◽  
Arterial Blood Flow ◽  
Recurrent Ulcer ◽  
Functional Changes ◽  
Arterial Blood ◽  
Clinical Stages ◽  
The Mean ◽  
Stage 1

Background Vascular dysfunction dominates the clinical picture of peripheral autonomic neuropathy in lower extremity. Patients and Methods We have studied functional changes of leg vasculature in 30 patients with chronic ulceration due to peripheral autonomic neuropathy between clinical stages 1 and 3. They suffered from lower extremity wounds. After sympathetic skin response test, pedal arterial blood flow analysis including peak systolic velocity (PSV) and pulsatility index (PI) was made by duplex ultrasonography (DUS) in involved legs. Vascular anatomy of leg was also examined by magnetic resonance angiography. Results The mean PSV value was found 58.32 cm/s in stage 1, 35.31 cm/s in stage 2, and 15.71 cm/s in stage 3. The mean PI value was observed 1.17 in stage 1, 1.43 in stage 2, and 1.87 in stage 3. In chronic stage 3, three patients had inadequate arterial blood supply and recurrent ulcer. Conclusions We suggest that reduced sympathetic activity due to small fiber neuropathy causes temporal variations in leg blood flow. There was a nonlinear relationship between vascular functional changes and stages of disease with increased, intermediate, and decreased blood flow, respectively. DUS assessment of pedal arteries contributed to differentiation of clinical stages and permitted vascular evaluation in the course of peripheral autonomic neuropathy.

Turbulent convection in a horizontal layer of water

1973 ◽  
Vol 60 (1) ◽  
pp. 141-159 ◽  
Author(s):  
T. Y. Chu ◽  
R. J. Goldstein
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Rayleigh Number ◽  
Power Law ◽  
Bounding Surface ◽  
Interferometric Method ◽  
Number Range ◽  
Mean Temperature ◽  
The Mean ◽  
Rayleigh Numbers

Overall heat transfer and mean temperature distribution measurements have been made of turbulent thermal convection in horizontal water layers heated from below. The Nusselt number is found to be proportional to Ra0·278 in the range 2·76 × 105 < Ra < 1·05 × 108. Eight discrete heat flux transitions are found in this Rayleigh number range. An interferometric method is used to measure the mean temperature distribution for Rayleigh numbers between 3·11 × 105 and 1·86 × 107. Direct visual and photographic observations of the fluctuating interferogram patterns show that the main heat transfer mechanism is the release of thermals from the boundary layers. For relatively low Rayleigh numbers (up to 5 × 105) many of the thermals reach the opposite surface and coalesce to form large masses of relatively warm fluid near the cold surface and masses of cold fluid near the warm surface, resulting in a temperature-gradient reversal. With increasing Rayleigh numbers, fewer and fewer thermals reach the opposite bounding surface and the thermals show persistent horizontal movements near the bounding surfaces. The central region of the layer becomes an isothermal core. The mean temperature distributions for the high Rayleigh number range are found to follow a Z−2 power law over a considerable range, where Z is the distance from the bounding surface. A very limited agreement with the theoretically predicted Z−1 power law is also found.

Determination of Localized Skin Temperature of the Transtibial Residual Limb

2020 ◽  
Author(s):  
Kamiar Ghoseiri ◽  
Mostafa Allami ◽  
Justin R. Murphy ◽  
Phil Page ◽  
Duane C. Button
Keyword(s):  
Skin Temperature ◽  
Clinical Characteristics ◽  
Blood Perfusion ◽  
Cross Sectional Study ◽  
Temperature Pattern ◽  
Residual Limb ◽  
Cross Sectional ◽  
Unequal Distribution ◽  
Study Participants ◽  
Transtibial Amputees

Abstract Background: Interventions to resolve thermal discomfort as a common complaint in amputees, are usually chosen based on the residual limb skin temperature while wearing prosthesis; whereas, less attention was paid to residual limb skin temperature while outside of the prosthesis. The objective of this study was to explore the localized and regional skin temperature over the transtibial residual limb (TRL) while outside of the prosthesis.Methods: Eight unilateral transtibial amputees were enrolled in this cross sectional study. Participants sat on a chair and rested for 30 minutes while their prosthesis was removed. Twelve sites were marked in four columns (anterolateral, anteromedial, posteromedial, and posterolateral) and three rows (proximal, middle, and distal) over the residual limb and used for attachment of analog thermistors. Skin temperature was recorded and compared during 11 minutes. Furthermore, the relationship of skin temperature with participants’ demographic and clinical characteristics were explored.Results: The middle and distal zones of the anteromedial column had the highest and lowest skin temperatures (29.8 and 26.3°C, p<0.05), respectively. The average temperature of the TRL was 27.73±0.83°C and had no significant relationships (p>0.05) with participants’ demographic and clinical characteristics.Conclusions: An unequal distribution of temperature over the TRL was found with significantly higher and lower temperatures at its anterior column and distal row, respectively. This temperature pattern should be considered for thermoregulation strategies. Further investigation of the residual limb temperature while considering muscles thickness and blood perfusion rate are warranted with and without prosthesis.

scholarly journals Application of shortwave diathermy to lower limb increases arterial blood flow velocity and skin temperature in women: a randomized controlled trial

2017 ◽  
Vol 21 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Natanael Teixeira Alves De Sousa ◽  
Elaine Caldeira De Oliveira Guirro ◽  
João Guilherme Calió ◽  
Mariane Cristina De Queluz ◽  
Rinaldo Roberto De Jesus Guirro
Keyword(s):  
Randomized Controlled Trial ◽  
Blood Flow ◽  
Flow Velocity ◽  
Skin Temperature ◽  
Blood Flow Velocity ◽  
Lower Limb ◽  
Controlled Trial ◽  
Arterial Blood Flow ◽  
Randomized Controlled ◽  
Arterial Blood

scholarly journals An Exploratory Study on the Relationship between Brachial Arterial Blood Flow and Cardiac Output

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Sixiang Jia ◽  
Yiteng Wu ◽  
Wei Wang ◽  
Wenting Lin ◽  
Yiwen Chen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Brachial Artery ◽  
Theoretical Basis ◽  
Arterial Blood Flow ◽  
Artery Blood Flow ◽  
Korotkoff Sound ◽  
Arterial Blood ◽  
The Mean ◽  
The Relationship

Background. We have obtained prospective clinical outcomes using the brachial artery largely, such as Korotkoff sound and vasomotor function measurement by ultrasound guidance to predict the prognosis of cardiovascular diseases. Very few reports on the quantitative measurement of the relationship between the brachial artery blood flow and cardiac output have been reported. Purpose. (1) To investigate whether the quantitative relationship between the brachial artery blood flow and cardiac output existed. (2) To provide a theoretical basis for taking advantage of artificial intelligence (AI) using Korotkoff sound analogously as far as possible to predict the cardiac output. Methods. A total of 586 patients who underwent cardiac color ultrasound in our center from 2021.3 to 2021.7 were included for analyses. The vascular parameters of the right upper limb brachial artery (such as the Diameter, Area, Blood Velocity, and Flow) were measured immediately after the cardiac color ultrasound, and some basic clinical parameters (Age, Sex, BMI, and Disease) were recorded subsequently. Ultimately, the Mann–Whitney and independent sample T-test were used to analyze the data. Results. (1) The mean Rate of the brachial arterial blood flow to cardiac output was 1.23%, and the mean 95% CI was (1.18%, 1.29%), indicating that the value was mainly concentrated in the current value interval. The indicator demonstrates that there is no significant difference currently among the patients with hypertension, coronary heart disease, and cardiac dysfunction. (2) The brachial artery wall diameter (Dist) is significantly thicker in patients with coronary heart disease and hypertension compared to patients with other cardiovascular diseases. (3) Cardiac output augments remarkably in patients with hypertension. Conclusion. Our study suggests that the Rate (brachial artery blood flow/cardiac output) is a constant of 1.23% approximately. It provides a theoretical basis for the subsequent application of the artificial intelligence (AI) method to predict heart function using Korotkoff sound, cope with large computational amounts, and improve computational speed. It is also indirectly proved that hypertension can lead to a change in peripheral vascular hyperplasia and increase cardiac output.

Impact of Combustion Chamber Dynamics on the Temperature Distribution in a Resonator

2019 ◽  
Author(s):  
Michael Betz ◽  
Max Zahn ◽  
Christoph Hirsch ◽  
Thomas Sattelmayer
Keyword(s):  
Temperature Distribution ◽  
Mass Flow ◽  
Acoustic Pressure ◽  
Air Mass ◽  
Hot Gas ◽  
Mean Temperature ◽  
Annular Combustor ◽  
Cooling Phase ◽  
The Mean ◽  
Number Of Cycles

Abstract The results of an experimental study on the influence of the purge air mass flow and the acoustic pressure in an annular combustor test rig on the temperature distribution in resonators with perforated plates at the exit are provided in the paper. The amplitude of the acoustic pressure in the combustor is found to have a high impact on the mean temperature and thus on the performance of the resonators, which originates primarily from the temperature sensitivity of the effective eigenfrequency. In the experiments the temperature in the cavity of one of the resonators is spatially and temporally resolved at 13 locations. The dependence of the mean temperature change on the combustor amplitudes and the purge air mass flow is measured quantitatively. In addition, the axial temperature gradient of the resonator is resolved. The mean temperature changes up to 8% depending on the level of siren forcing. Using acoustic pressure data from the cavity, the velocity of the hot gas jets periodically entering the resonator is calculated. If high amplitudes occur in the combustor and there is no adequate purge air flow in the resonators then hot gas ingestion into the cavity of the resonator occurs, leading to detuning of the resonator and the breakdown of its performance. Once hot gas ingestion occurs, the resonator quickly heats up within a few seconds as the generation of the mixture of hot gas and purge air requires only a low number of cycles. This leads to a thermal runaway of the frequency range of the resonator with high damping. When the combustor returns to quiet operation, a cooling phase with two different time constants is observed.

scholarly journals Validation of the mean systemic filling pressure assessment with preserved arterial blood flow by comparing two methods of calculation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roberto Alberto De Blasi ◽  
Stefano Finazzi
Keyword(s):  
Filling Pressure ◽  
Arterial Blood Flow ◽  
Venous Compliance ◽  
Mean Systemic Filling Pressure ◽  
Model Method ◽  
Arterial Blood ◽  
Methods Of Calculation ◽  
Systemic Filling ◽  
The Mean ◽  
Systemic Filling Pressure

AbstractWe developed a method for measuring in vivo venular volumes and the mean systemic filling pressure in the limbs using near-infrared spectroscopy (NIRS). We aimed to validate the NIRS methodology by comparing two independent methods of calculation based on different physiological approaches. Pressure–volumes (P–V) curves were recorded following graded venous occlusion on the forearm. Values from a P–V curves analysis model (method 1) were compared with data derived from a resistor-capacitance calculation model (method 2) based on arterial pressure and venous compliance. We tested these methods on 10 healthy participants at rest and during exercise and on 6 severely ill patients. Results from method 1 were comparable with those calculated by method 2. Venular volumes calculated using method 1 correlated linearly with those calculated using method 2 both in participants (R2 = 0.98) and in patients (R2 = 0.94). A good agreement between methods was shown with few values out of the range of ± 1.96 standard deviation. Our findings added mathematical consistency for the NIRS methodology validation in the venular P–V assessment with no flow interruption. Further research will be required to confirm the relevance of the methodology in the clinical setting.

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