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Stading, M., Waqas, M. Q., Holmberg, F., Wiklund, J., Kotze, R. & Ekberg, O. (2019). A Device that Models Human Swallowing. Dysphagia (New York. Print)
Open this publication in new window or tab >>A Device that Models Human Swallowing
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2019 (English)In: Dysphagia (New York. Print), ISSN 0179-051X, E-ISSN 1432-0460Article in journal (Refereed) Epub ahead of print
Abstract [en]

The pharynx is critical for correct swallowing, facilitating the transport of both air and food transport in a highly coordinated manner, and aberrant co-ordination causes swallowing disorders (dysphagia). In this work, an in vitro model of swallowing was designed to investigate the role of rheology in swallowing and for use as a pre-clinical tool for simulation of different routes to dysphagia. The model is based on the geometry of the human pharynx. Manometry is used for pressure measurements and ultrasonic analysis is performed to analyze the flow profiles and determine shear rate in the bolus, the latter being vital information largely missing in literature. In the fully automated model, bolus injection, epiglottis/nasopharynx movement, and ultrasound transducer positioning can be controlled. Simulation of closing of the airways and nasal cavity is modulated by the software, as is a clamping valve that simulates the upper esophageal sphincter. The actions can be timed and valves opened to different degrees, resembling pathologic swallowing conditions. To validate measurements of the velocity profile and manometry, continuous and bolus flow was performed. The respective velocity profiles demonstrated the accuracy and validity of the flow characterization necessary for determining bolus flow. A maximum bolus shear rate of 80 s−1 was noted for syrup-consistency fluids. Similarly, the manometry data acquired compared very well with clinical studies. © 2019, The Author(s).

Keywords
Deglutition, Deglutition disorders, In vitro, Manometry, Pharynx, Rheology, Shear rate
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37754 (URN)10.1007/s00455-018-09969-2 (DOI)2-s2.0-85060660119 (Scopus ID)
Available from: 2019-02-11 Created: 2019-02-11 Last updated: 2019-02-11Bibliographically approved
Meacci, V., Matera, R., Wiklund, J. & Ricci, S. (2019). Real-time in-line industrial fluids characterization using multiple pulse repetition frequency. In: Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 512): . Paper presented at Lect. Notes Electr. Eng. 21 September 2017 through 22 September 2017 (pp. 73-79).
Open this publication in new window or tab >>Real-time in-line industrial fluids characterization using multiple pulse repetition frequency
2019 (English)In: Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 512), 2019, p. 73-79Conference paper, Published paper (Refereed)
Abstract [en]

The characterization of fluids flowing in industrial pipes is of paramount importance to optimize the production process and guarantee the final product quality in most industries. Rheological parameters of the fluid can be efficiently calculated starting from the Pressure Drop (PD) along a tract of the pipe, and the velocity profile that the flow develops along the pipe diameter, which can be assessed through Ultrasounds Pulsed Wave Doppler (PWD). Unfortunately, in PWD the maximum detectable velocity is restricted by the aliasing limit related to the Pulse Repetition Frequency (PRF). The use of PRF sequences at different rate can recover de-aliased velocities by combining the aliased data. In this work, we extend the capabilities of an embedded PWD ultrasound system used to characterize industrial fluids by implementing, in real-time, the multi-PRF method.

Keywords
Doppler measurement, Fluid characterization, Nyquist velocity extension, Staggered double-PRE, Velocity, Detectable velocity, Nyquist, Pulse repetition frequencies, Pulsed-wave Doppler, Rheological parameter, Electronics industry
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-34357 (URN)10.1007/978-3-319-93082-4_10 (DOI)2-s2.0-85050398246 (Scopus ID)9783319930817 (ISBN)
Conference
Lect. Notes Electr. Eng. 21 September 2017 through 22 September 2017
Available from: 2018-08-07 Created: 2018-08-07 Last updated: 2018-08-07Bibliographically approved
Ricci, S., Meacci, V., Birkhofer, B. & Wiklund, J. (2017). Embedded system for In-line characterization of industrial fluids. In: Lecture Notes in Electrical Engineering: . Paper presented at ApplePies: International Conference on Applications in Electronics Pervading Industry, Environment and Society. Rome, Italy. 15-16 September 2016 (pp. 43-49).
Open this publication in new window or tab >>Embedded system for In-line characterization of industrial fluids
2017 (English)In: Lecture Notes in Electrical Engineering, 2017, p. 43-49Conference paper, Published paper (Refereed)
Abstract [en]

The in-line assessment of the rheological properties of fluids in chemical, cosmetic, pharmaceutical, and food industries is fundamental for process optimization and product quality. The rheology of a fluid in a process pipe can be investigated by combining the measured pressure difference over a fixed distance of pipe, and the velocity distribution of the fluid along the diameter. The latter data can be measured by Pulsed Ultrasound Velocimetry (PUV), which is a non-invasive Doppler technique. Till now, the few systems available need cumbersome electronics or computer for data post-processing and are not suitable for industrial applications. In this work we present a compact (10 × 12 cm), fully programmable and low cost system that embeds the ultrasound front-end and all of the digital electronics necessary for the signal processing. The board produces, in real time, 512-point velocity profiles at 45 Hz rate and is integrated in the Flow-VizTM platform (SP Technical Research Institute of Sweden).

Keywords
Optimization, Signal processing, Ultrasonic applications, Data post processing, Digital electronics, Doppler techniques, Fully programmables, Pressure differences, Rheological property, Technical research, Ultrasound front end, Data handling
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ri:diva-29195 (URN)10.1007/978-3-319-47913-2_6 (DOI)2-s2.0-85008467227 (Scopus ID)
Conference
ApplePies: International Conference on Applications in Electronics Pervading Industry, Environment and Society. Rome, Italy. 15-16 September 2016
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2018-07-20Bibliographically approved
Ricci, S., Meacci, V., Birkhofer, B. & Wiklund, J. (2017). FPGA-based system for in-line measurement of velocity profiles of fluids in industrial pipe flow. IEEE transactions on industrial electronics (1982. Print), 64(5), 3997-4005
Open this publication in new window or tab >>FPGA-based system for in-line measurement of velocity profiles of fluids in industrial pipe flow
2017 (English)In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 64, no 5, p. 3997-4005Article in journal (Refereed) Published
Abstract [en]

The rheology of a fluid flowing in an industrial process pipe can be calculated by combining the pressure drop and the velocity profile that the fluid develops across the tube diameter. The profile is obtained noninvasively through an ultrasound Doppler investigation. Unfortunately, at present, no system capable of real-time velocity profile assessment is available for in-line industrial rheological measurements, and tests are operated by manually moving fluid specimens to specialized laboratories. In this work, we present an embedded system capable of in-line and real-time measurement of velocity profile and pressure drop, which enables the automatic rheological characterization of non-Newtonian fluids in process pipes. The system includes all the electronics for the ultrasound front-end, as well as the digital devices for the real-time calculation of the velocity profile. The proposed system is highly programmable, low-noise, and specifically targeted for industrial use. It is shown capable of producing, for example, 512-point velocity profiles at 45 Hz rate. An application is presented where a sludge fluid, flowing at 600 L/min in a 48 mm diameter high-grade stainless steel pipe, is characterized in real-time with a ±5% accuracy.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2017
Keywords
Doppler measurement, Fluid characterization, Fluid flow control, Fluid flow measurement, Digital devices, Drops, Field programmable gate arrays (FPGA), Flow measurement, Non Newtonian flow, Non Newtonian liquids, Pressure drop, Rheology, Stainless steel, Ultrasonics, Velocity, In-line measurements, Non-Newtonian fluids, Real time measurements, Real-time calculations, Rheological characterization, Rheological measurements, Flow of fluids
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:ri:diva-29780 (URN)10.1109/TIE.2016.2645503 (DOI)2-s2.0-85018962094 (Scopus ID)
Available from: 2017-06-12 Created: 2017-06-12 Last updated: 2018-07-20Bibliographically approved
Håkansson, U., Wiklund, J. & Kotzé, M. (2017). In-Line Determination of Cement-Based Grout Properties Using a Pulsed Ultrasound Based Method and System. In: Geotechnical Special Publication: . Paper presented at 5th International Conference on Grouting, Deep Mixing, and Diaphragm Walls, Grouting 2017, 9 July 2017 through 12 July 2017 (pp. 356-367). (288 GSP)
Open this publication in new window or tab >>In-Line Determination of Cement-Based Grout Properties Using a Pulsed Ultrasound Based Method and System
2017 (English)In: Geotechnical Special Publication, 2017, no 288 GSP, p. 356-367Conference paper, Published paper (Refereed)
Abstract [en]

In construction, grouting is used to improve or alter the natural properties of soil or rock by injecting a grout into the pores or fractures of the formation. In order to predict the grout penetration progress and maximum penetration length, modern methods for grouting design involve a detailed knowledge of the rheological properties of the used grout. Today, rheological properties of grouts are measured either in a laboratory with conventional rheometers or in the field with simple devices. Due to the complex flow behavior of cement-based grouts, being non-Newtonian yield stress fluids with history and time dependent rheological properties, the results are non-consistent, device dependent and strongly influenced by the test procedure and operator. No standard measurement method is available for rheological characterization of grouts in the grouting industry today. In order to improve this unfortunate situation a new complete measuring methodology, based on pulsed ultrasound, is proposed. The method has been tested for cement-based grouts, with good results. In this work, a new container-based field laboratory is presented, equipped with the Flow-Viz system, which is designed for in-line measurements of rheological properties of cement-based grouts under field-like conditions. Results obtained under field-like conditions are presented in order to demonstrate the applicability of the new system.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-31114 (URN)10.1061/9780784480793.034 (DOI)2-s2.0-85025465382 (Scopus ID)
Conference
5th International Conference on Grouting, Deep Mixing, and Diaphragm Walls, Grouting 2017, 9 July 2017 through 12 July 2017
Available from: 2017-08-28 Created: 2017-08-28 Last updated: 2019-01-03Bibliographically approved
Ricci, S., Meacci, V. & Wiklund, J. (2017). Real-time staggered PRF for in-line industrial fluids characterization. In: IEEE International Ultrasonics Symposium, IUS: . Paper presented at 2017 IEEE International Ultrasonics Symposium, IUS 2017, 6 September 2017 through 9 September 2017. IEEE Computer Society
Open this publication in new window or tab >>Real-time staggered PRF for in-line industrial fluids characterization
2017 (English)In: IEEE International Ultrasonics Symposium, IUS, IEEE Computer Society , 2017Conference paper, Published paper (Refereed)
Abstract [en]

Modern industries need to monitor every step of the production process for a better efficiency and product quality. However, important parameters, like the rheological indexes of the fluids involved in the process, cannot easily be inspected inline, as they are typically analyzed through off-line laboratory tests on specimens. Recently, electronics sensors have been introduced capable to characterize in-line the fluids by acquiring the velocity profile of the fluid flowing in a pipe, and the pressure drop. These sensors are based on Pulsed Wave Doppler (PWD), where ultrasound energy bursts are transmitted at Pulse Repetition Frequency (PRF) rate. The fluid maximum velocity that can be safely investigated in PWD is constrained by the PRF, which is limited by the investigation depth. Unfortunately, in large industrial pipes, the fluid velocity can be easily beyond the Nyquist limit, preventing a correct ultrasound investigation. Staggered PRF is a technique typically used in Doppler radar that, by exploiting PRF sequences at different rate, can recover the right velocity even if beyond the Nyquist limit. In this work, an embedded ultrasound system for in-line rheological investigation is updated by implementing in its Field Programmable Gate Array (FPGA) the staggered PRF technique. Experiments show the system capable of detecting velocity profiles at 25 Hz rate beyond the Nyquist limit.

Place, publisher, year, edition, pages
IEEE Computer Society, 2017
Keywords
Doppler measurement, Fluid characterization, Nyquist velocity extension, Staggered double-PRF
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-38048 (URN)10.1109/ULTSYM.2017.8092075 (DOI)2-s2.0-85039454157 (Scopus ID)9781538633830 (ISBN)
Conference
2017 IEEE International Ultrasonics Symposium, IUS 2017, 6 September 2017 through 9 September 2017
Available from: 2019-03-19 Created: 2019-03-19 Last updated: 2019-03-22Bibliographically approved
Qasi, W., Wiklund, J., Ekberg, O., Altskär, A. & Stading, M. (2017). Shear and extensional rheology of commercial thickeners used for dysphagia management. Journal of texture studies, 48(6), 507-517
Open this publication in new window or tab >>Shear and extensional rheology of commercial thickeners used for dysphagia management
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2017 (English)In: Journal of texture studies, ISSN 0022-4901, E-ISSN 1745-4603, Vol. 48, no 6, p. 507-517Article in journal (Refereed) Published
Abstract [en]

People who suffer from swallowing disorders, commonly referred to as dysphagia, are often restricted to a texture-modified diet. In such a diet, the texture of the fluid is modified mainly by the addition of gum or starch-based thickeners. For optimal modification of the texture, tunable rheological parameters are shear viscosity, yield stress, and elasticity. In this work, the flow properties of commercial thickeners obtained from major commercial suppliers were measured both in shear and extensional flow using a laboratory viscometer and a newly developed tube viscometry technique, termed Pulsed Ultrasound Velocimetry plus Pressure Drop (PUV+PD). The two methods gave similar results, demonstrating that the PUV+PD technique can be applied to study flow during the swallowing process in geometry similar to that of the swallowing tract. The thickeners were characterized in relation to extensional viscosity using the Hyperbolic Contraction Flow (HCF) method, with microscopy used as a complementary method for visualization of the fluid structure. The gum-based thickeners had significantly higher extensional viscosities than the starch-based thickeners. The rheological behavior was manifested in the microstructure as a hydrocolloid network with dimensions in the nanometer range for the gum-based thickeners. The starch-based thickeners displayed a granular structure in the micrometer range. In addition, the commercial thickeners were compared to model fluids (Boger, Newtonian and Shear-thinning) set to equal shear viscosity at 50s−1 and it was demonstrated that their rheological behavior could be tuned between highly elastic, extension-thickening to Newtonian. This article is protected by copyright. All rights reserved.

Keywords
Dysphagia, thickeners, extensional viscosity, fluid elasticity, microstructure, velocity profile
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-29262 (URN)10.1111/jtxs.12264 (DOI)2-s2.0-85018743329 (Scopus ID)
Available from: 2017-04-07 Created: 2017-04-07 Last updated: 2019-01-03Bibliographically approved
Rahman, M., Wiklund, J., Kotzé, R. & Håkansson, U. (2017). Yield stress of cement grouts. Tunnelling and Underground Space Technology, 61, 50-60
Open this publication in new window or tab >>Yield stress of cement grouts
2017 (English)In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 61, p. 50-60Article in journal (Refereed) Published
Abstract [en]

The rheology of cement grout is complex due to its thixotropic nature and the presence of a yield stress. Despite the importance of the yield stress for grouting design, no standard methods are yet available to determine the yield stress. Most common methods are based on using conventional rheometers, but the results are subjective due to the measurement techniques, applied shear history and hydration. In this work, measurement of the yield stress of cement grout was performed with different measurement techniques using a conventional rheometer. In addition, in-line measurements using an ultrasound based technique were made in order to visualize the flow profile and perform a direct measurement of the yield stress. Two ranges of yield stress, static and dynamic yield stress, were measured. These results should be used for design purposes depending on the prevailing shear rate. The ultrasound based Flow Viz industrial rheometer was found capable of performing direct in-line measurement of the yield stress and providing a detailed visualization of the velocity profile of cement grout.

Keywords
Cement grout, In-line rheology, Pulsed Ultrasound Velocimetry + Pressure Difference, Thixotropy, Yield stress, Cements, Dielectric losses, Elasticity, Grouting, Mortar, pH effects, Prestressed materials, Rheometers, Ultrasonic applications, Cement grouts, Direct measurement, Grouting designs, In-line measurements, Measurement techniques, Pressure differences, Velocity profiles
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-31127 (URN)10.1016/j.tust.2016.09.009 (DOI)2-s2.0-84988643522 (Scopus ID)
Available from: 2017-08-28 Created: 2017-08-28 Last updated: 2019-01-22Bibliographically approved
Qazi, W. M., Wiklund, J., Ekberg, O. & Stading, M. (2016). A swallowing model for efficient food product development. In: The Materials Science Graduate Student Days 2016: . Paper presented at The Materials Science Graduate Student Days 2016, February 23-24, 2016, Gothenburg, Sweden (pp. 38). , Article ID P20.
Open this publication in new window or tab >>A swallowing model for efficient food product development
2016 (English)In: The Materials Science Graduate Student Days 2016, 2016, p. 38-, article id P20Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Dysphagia refers to difficulties in swallowing, caused by conditions ranging from trauma to neurological disorders such as dementia. People suffering from dysphagia cannot adequately transfer food from the mouth to the stomach especially low viscosity, fluid foods. Texture modification is imperative to ensure safe passage of food from mouth into the stomach. Food products with elastic properties, i.e. high extensional viscosity, have been identified as helpful in promoting safe swallowing. However, this hypothesis is difficult to prove by clinical studies due to ethical issues and availability of suitable patients. Moreover, the problems of individual patients vary largely in nature and extent which further complicates the matter as identified in our previous research (1). We are currently constructing an in vitro human swallowing apparatus mimicking swallowing through the pharynx to the esophagus. The apparatus will have the pressure and ultrasound sensors to monitor real time flow properties of the bolus as it travels along the swallowing tract. This will enable us to measure relevant parameters during swallowing such as residence times and bolus velocity along the way. The model can be adjusted to different dysphagic conditions such as abnormal epiglottis closure. The goal of the project is to develop food products for safe swallowing and currently we are determining the rheological properties of commercial dysphagia thickeners, as well as model fluids. Two companies active in dysphagia foods are contributing (Fresenius Kabi and Findus). The shear and extensional properties have been shown to vary significantly, which has been correlated with fluid microstructure.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-27874 (URN)
Conference
The Materials Science Graduate Student Days 2016, February 23-24, 2016, Gothenburg, Sweden
Available from: 2017-01-16 Created: 2017-01-16 Last updated: 2019-06-11Bibliographically approved
Kotzé, R., Wiklund, J. & Haldenwang, R. (2016). Application of ultrasound Doppler technique for in-line rheological characterization and flow visualization of concentrated suspensions. Canadian Journal of Chemical Engineering, 94(6), 1066-1075
Open this publication in new window or tab >>Application of ultrasound Doppler technique for in-line rheological characterization and flow visualization of concentrated suspensions
2016 (English)In: Canadian Journal of Chemical Engineering, ISSN 0008-4034, E-ISSN 1939-019X, Vol. 94, no 6, p. 1066-1075Article in journal (Refereed) Published
Abstract [en]

Ultrasonic velocity profiling (UVP) is a technique that can measure an instantaneous one-dimensional velocity profile in a fluid containing particles across the ultrasonic beam axis or measurement line. A method for in-line rheometry combining the UVP technique with pressure difference (PD) measurements (UVP+PD), was developed and improved at SP - Technical Research Institute of Sweden and the Cape Peninsula University of Technology, South Africa. The UVP+PD methodology allows measurements that are not possible with common rheometers such as radial velocity profiles and yield stress directly in-line and under true dynamic process conditions. Furthermore, it has advantages over commercially available process rheometers and offline instruments in being non-invasive, applicable to opaque and concentrated suspensions, and having small sensor dimensions. It has been evaluated for several potential industrial applications including paper pulp, foods, transient flows, and model mineral suspensions. Similarly, the UVP technique can be applied to an open-channel flow by combining flow depth measurements to obtain rheological properties in-line. Industrial fluids, such as thickened pastes, commonly found in tailings transportation exhibit wide particle size distributions, large particle sizes, and very high viscosities. These industrial fluids cause strong attenuation of the ultrasound energy, which can significantly distort velocity profiles measured with the UVP technique or even make it impossible to conduct flow measurements. Initial results obtained in concentrated cement pastes and grouts (bentonite and kaolin clay) showed that UVP is a feasible and promising technique for flow characterization in viscous fluids.

Place, publisher, year, edition, pages
Wiley-Liss Inc., 2016
Keywords
Non-Newtonian, Open channel, Rheology, Ultrasonic velocity profiling, UVP+PD methodology
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-406 (URN)10.1002/cjce.22486 (DOI)
Available from: 2016-06-22 Created: 2016-06-22 Last updated: 2019-06-11Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7856-2324

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