24 research outputs found
Planning the Workspace for the Repair of Electrical Machines at Intrac Eesti AS
No full textTänapäeva maailmas on tihe nähtus, kus masinate tootjad tulevad lagedale uute
masinatega, mis töötavad kõrgepingega akudega. Selle mõjuks on seadused keskkonna
säästmise eesmärgil. Käesolev lõputöö keskendub elektrimasinate tööala projekteerimisel
ettevõttes Intrac Eesti AS. Tööala projekteerimiseks võeti näidismasin, milleks on Manitou
MRT 2660 E. See on elektriline pöörlev teleskooplaadur, mis on suuruselt kõige suurem
elektriline masin, mis on ettevõttesse saabumas.
Lõputöö eesmärk oli pakkuda lahendus, mis võimaldaks elektrimasinate remonti ja
hooldust teostada võimalikult ohutult ja efektiivselt. Sellega seoses tutvustati ettevõtet
ning ka vastavat masina brändi. Samuti analüüsiti seaduseid ja standardeid, mis on seotud
kõrgepinge masinate remondi ja hooldusega. Seadused ja standardid võeti analüüsimise
alla Eesti kui ka Euroopa vaates. Teoreetilises osas tutvustati veel näidismasinat ning selle
kõrgepinge süsteeme. Veel tehti võrdlus sisepõlemis- ja elektrimootoriga masina vahel.
Võrdluses on näha, et autonoomsuse ning hoolduse kulud on elektrimasinal pea poole võrra
väiksemad. Välja toodi ka tehasepoolsete koolituste nõuded MRT 2660 E remontimisel ja
hooldamisel. Sellest oli näha, et koolitatavad tehnikud peavad läbima mitmeid virtuaalseid
koolitusi ja siis minema mitme päevasele koolituse, et teadmisi arendada. Koolituste osas
tuleb tehnikutel läbida veel esmaabi-ja elektriohutuskoolitus.
Praktilises osas toodi välja Intrac Eesti AS praeguse töökoja joonis koos selle mõõtmetega.
Elektrimasinate tööala projekteerimise käigus keskenduti töökoja ruumipaigutusele.
Tööala projekteeriti teenindushalli sisenedes vasakule poole esimesele masina kohale,
mille suuruseks on 9 x 7 meetrit. Selle eesmärk on ohu vähendamine tuleohtliku olukorra
korral. Sellest kohast on masinat välja tõmmata kõige lihtsam. Seejärel tehti nimekirjad
vajalike investeeringute tegemiseks. Investeeringute alla kuulusid töövahendid, kui ka
ohualaga seotud märgised ja piirded. Investeeringute kogusummaks tuli 5301,79€. See
summa ei ole täielikult täpne, kuna tehasepoolsete koolituste hinda ei avaldata ning
summad võivad erineda olenevalt ettevõtte valikutele.
Autor leiab, et lõputöö raames tehti tööala projekteerimine võimalikult efektiivsesse kohta.
Samuti pakuti välja konkreetsed lahendused ning vajalikud investeeringud selle
rajamiseks. Samuti toodi välja soovitused riskianalüüsi uuendamisega seotud punktid.
Autor soovitab elektrimasinate tööala lahendada just selliselt nagu töös välja on toodud.
Kindlasti peab järgima vastavate töövahendite ja ohutusvahendite soetamist.Planning the Workspace for the Repair of Electrical Machines at Intrac Eesti AS
This thesis focused on the design of the work area for electric machines at Intrac Eesti AS,
with a particular emphasis on the Manitou MRT 2660 E, the company’s largest electric
rotating telehandler.
The relevance of this research stems from the growing demand for eco-friendly machinery
and the need for safe and efficient maintenance practices. The main objective of this thesis
is to propose solutions that facilitate the safe and effective repair of electric machines while
ensuring compliance with applicable laws and safety standards.
Key objectives include a comprehensive analysis of the laws and standards governing the
maintenance and repair of high-voltage equipment, both in Estonia and across Europe. The
thesis also provides an overview of the specific machine and its high-voltage systems,
comparing the operational and maintenance costs of electric machines to those powered
by internal combustion engines. Notably, the findings indicate that electric machines can
have maintenance costs that are nearly fifty percent lower. The author addresses the
required training for technicians involved in the maintenance and repair of the MRT 2660
E, highlighting the necessity for them to complete various virtual training modules followed
by extended in-person training sessions. Additionally, these technicians must undergo
training in first aid and electrical safety.
In the practical section, the current layout of the Intrac Eesti AS workshop is detailed,
including its dimensions. The design of the work area prioritized efficient spatial
organization, positioning the designated area for electric machine maintenance to the left
upon entry to the service hall, measuring 9 x 7 meters. This strategic placement aims to
reduce fire hazard risks and facilitate easier machine retrieval.
A thorough list of necessary investments for establishing this work area was created,
including tools as well as safety signage and barriers. Total estimated cost came to
€5301,79€. This figure may vary due to the undisclosed costs for manufacturer training
and other procurement choices made by the company.
In conclusion, the author believes that the work area design was executed effectively,
providing concrete solutions and outlining the necessary investments for its establishment.
Recommendations are made to implement the proposed layout, ensuring the acquisition
of appropriate equipment and safety measures. This design not only enhances operational
efficiency but also aligns with crucial safety standards for maintaining high-voltage electric
machines
Phantom validation of quantitative Y-90 PET/CT-based dosimetry in liver radioembolization
No full textBackground: PET/CT has recently been shown to be a viable alternative to traditional post-infusion imaging methods
providing good quality images of 90Y-laden microspheres after selective internal radiation therapy (SIRT). In the present
paper, first we assessed the quantitative accuracy of 90Y-PET using an anthropomorphic phantom provided with lungs,
liver, spine, and a cylindrical homemade lesion located into the hepatic compartment. Then, we explored the accuracy
of different computational approaches on dose calculation, including (I) direct Monte Carlo radiation transport using
Raydose, (II) Kernel convolution using Philips Stratos, (III) local deposition algorithm, (IV) Monte Carlo technique (MCNP)
considering a uniform activity distribution, and (V) MIRD (Medical Internal Radiation Dose) analytical approach. Finally,
calculated absorbed doses were compared with those obtained performing measurements with LiF:Mg,Cu,P TLD chips
in a liquid environment.
Results: Our results indicate that despite 90Y-PET being likely to provide high-resolution images, the 90Y low branch
ratio, along with other image-degrading factors, may produce non-uniform activity maps, even in the presence of
uniform activity. A systematic underestimation of the recovered activity, both for the tumor insert and for the liver
background, was found. This is particularly true if no partial volume correction is applied through recovery coefficients.
All dose algorithms performed well, the worst case scenario providing an agreement between absorbed dose
evaluations within 20%. Average absorbed doses determined with the local deposition method are in excellent
agreement with those obtained using the MIRD and the kernel-convolution dose calculation approach.
Finally, absorbed dose assessed with MC codes are in good agreement with those obtained using TLD in liquid
solution, thus confirming the soundness of both calculation approaches. This is especially true for Raydose, which
provided an absorbed dose value within 3% of the measured dose, well within the stated uncertainties.
Conclusions: Patient-specific dosimetry is possible even in a scenario with low true coincidences and high random
fraction, as in 90Y–PET imaging, granted that accurate absolute PET calibration is performed and acquisition times are
sufficiently long. Despite Monte Carlo calculations seeming to outperform all dose estimation algorithms, our data
provide a strong argument for encouraging the use of the local deposition algorithm for routine 90Y dosimetry based
on PET/CT imaging, due to its simplicity of implementation
A multicentre comparison of quantitative 90 Y PET/CT for dosimetric purposes after radioembolization with resin microspheres
No full textInternational audiencePurpose: To investigate and compare the quantitative accuracy of (90)Y imaging across different generation PET/CT scanners, for the purpose of dosimetry after radioembolization with resin microspheres.Methods: A strict experimental and imaging protocol was followed by 47 international sites using the NEMA 2007/IEC 2008 PET body phantom with an 8-to-1 sphere-to-background ratio of (90)Y solution. The phantom was imaged over a 7-day period (activity ranging from 0.5 to 3.0 GBq) and all reconstructed data were analysed at a core laboratory for consistent processing. Quantitative accuracy was assessed through measures of total phantom activity, activity concentration in background and hot spheres, misplaced counts in a nonradioactive insert, and background variability.Results: Of the 69 scanners assessed, 37 had both time-of-flight (ToF) and resolution recovery (RR) capability. These current generation scanners from GE, Philips and Siemens could reconstruct background concentration measures to within 10% of true values over the evaluated range, with greater deviations on the Philips systems at low count rates, and demonstrated typical partial volume effects on hot sphere recovery, which dominated spheres of diameter 20 mm in diameter, activity concentrations were consistently underestimated by about 20%. Non-ToF scanners from GE Healthcare and Siemens were capable of producing accurate measures, but with inferior quantitative recovery compared with ToF systems.Conclusion: Current generation ToF scanners can consistently reconstruct (90)Y activity concentrations, but they underestimate activity concentrations in small structures (≤37 mm diameter) within a warm background due to partial volume effects and constraints of the reconstruction algorithm. At the highest count rates investigated, measures of background concentration (about 300 kBq/ml) could be estimated on average to within 1%, 5% and 2% for GE Healthcare (all-pass filter, RR + ToF), Philips (4i8s ToF) and Siemens (2i21s all-pass filter, RR + ToF) ToF systems, respectively. Over the range of activities investigated, comparable performance between GE Healthcare and Siemens ToF systems suggests suitability for quantitative analysis in a scenario analogous to that of postradioembolization imaging for treatment of liver cancer
Assessment of the relative contribution of volume and concentration changes in Yttrium-90 labelled resin microspheres on ionization chamber measurements
No full textA multicentre comparison of quantitative 90Y PET/CT for dosimetric purposes after radioembolization with resin microspheres
No full textA multicentre comparison of quantitative 90Y PET/CT for dosimetric purposes after radioembolization with resin microspheres: The QUEST Phantom Study
No full textPURPOSE: To investigate and compare the quantitative accuracy of (90)Y imaging across different generation PET/CT scanners, for the purpose of dosimetry after radioembolization with resin microspheres.\n\nMETHODS: A strict experimental and imaging protocol was followed by 47 international sites using the NEMA 2007/IEC 2008 PET body phantom with an 8-to-1 sphere-to-background ratio of (90)Y solution. The phantom was imaged over a 7-day period (activity ranging from 0.5 to 3.0 GBq) and all reconstructed data were analysed at a core laboratory for consistent processing. Quantitative accuracy was assessed through measures of total phantom activity, activity concentration in background and hot spheres, misplaced counts in a nonradioactive insert, and background variability.\n\nRESULTS: Of the 69 scanners assessed, 37 had both time-of-flight (ToF) and resolution recovery (RR) capability. These current generation scanners from GE, Philips and Siemens could reconstruct background concentration measures to within 10 % of true values over the evaluated range, with greater deviations on the Philips systems at low count rates, and demonstrated typical partial volume effects on hot sphere recovery, which dominated spheres of diameter 20 mm in diameter, activity concentrations were consistently underestimated by about 20 %. Non-ToF scanners from GE Healthcare and Siemens were capable of producing accurate measures, but with inferior quantitative recovery compared with ToF systems.\n\nCONCLUSION: Current generation ToF scanners can consistently reconstruct (90)Y activity concentrations, but they underestimate activity concentrations in small structures (≤37 mm diameter) within a warm background due to partial volume effects and constraints of the reconstruction algorithm. At the highest count rates investigated, measures of background concentration (about 300 kBq/ml) could be estimated on average to within 1 %, 5 % and 2 % for GE Healthcare (all-pass filter, RR + ToF), Philips (4i8s ToF) and Siemens (2i21s all-pass filter, RR + ToF) ToF systems, respectively. Over the range of activities investigated, comparable performance between GE Healthcare and Siemens ToF systems suggests suitability for quantitative analysis in a scenario analogous to that of postradioembolization imaging for treatment of liver cancer
99mTc-radiolabeled composites enabling in vivo imaging of arterial dispersal and retention of microspheres in the vascular network of rabbit lungs, liver, and liver tumors
No full textRoss W Stephens,1 Gregory D Tredwell,1 Karen J Knox,1 Lee A Philip,1 David W King,1 Kelly M Debono,2 Jessica L Bell,1 Tim J Senden,1 Marcel R Tanudji,3 Jillean G Winter,3 Stephanie A Bickley,3 Michael J Tapner,3 Stephen K Jones3 1The Biomedical Radiochemistry Laboratory, Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, ACT, Australia; 2Animal Services Division, Research School of Biology, Australian National University, Canberra, ACT, Australia; 3Research and Development, Sirtex Medical Limited, Sydney, NSW, Australia Purpose: Selective internal radiation therapy (SIRT) is an effective treatment option for liver tumors, using Y-90-loaded polymer microspheres that are delivered via catheterization of the hepatic artery. Since Y-90 is a beta emitter and not conveniently imaged by standard clinical instrumentation, dosimetry is currently evaluated in each patient using a surrogate particle, 99mTechnetium-labeled macroaggregated albumin (99mTc-MAA). We report a new composite consisting of 99mTc-labeled nanoparticles attached to the same polymer microspheres as used for SIRT, which can be imaged with standard SPECT.Methods: Carbon nanoparticles with an encapsulated core of 99mTc were coated with the polycation protamine sulfate to provide electrostatic attachment to anionic polystyrene sulfonate microspheres of different sizes (30, 12, and 8 µm). The in vivo stability of these composites was determined via intravenous injection and entrapment in the capillary network of normal rabbit lungs for up to 3 hours. Furthermore, we evaluated their biodistribution in normal rabbit livers, and livers implanted with VX2 tumors, following intrahepatic artery instillation. Results: We report distribution tests for three different sizes of radiolabeled microspheres and compare the results with those obtained using 99mTc-MAA. Lung retention of the radiolabeled microspheres ranged from 72.8% to 92.9%, with the smaller diameter microspheres showing the lowest retention. Liver retention of the microspheres was higher, with retention in normal livers ranging from 99.2% to 99.8%, and in livers with VX2 tumors from 98.2% to 99.2%. The radiolabeled microspheres clearly demonstrated preferential uptake at tumor sites due to the increased arterial perfusion produced by angiogenesis.Conclusion: We describe a novel use of radiolabeled carbon nanoparticles to generate an imageable microsphere that is stable in vivo under the shear stress conditions of arterial networks. Following intra-arterial instillation in the normal rabbit liver, they distribute in a distinct segmented pattern, with the smaller microspheres extending throughout the organ in finer detail, while still being well retained within the liver. Furthermore, in livers hosting an implanted VX2 tumor, they reveal the increased arterial perfusion of tumor tissue resulting from angiogenesis. These novel composites may have potential as a more representative mimic of the vascular distribution of therapeutic microspheres in patients undergoing SIRT. Keywords: liver cancer, SIRT, radiolabeled microspheres, medical imagin
A multicentre comparison of quantitative 90Y PET/CT for dosimetric purposes after radioembolization with resin microspheres
No full textPurpose: To investigate and compare the quantitative accuracy of 90Y imaging across different generation PET/CT scanners, for the purpose of dosimetry after radioembolization with resin microspheres.
Methods: A strict experimental and imaging protocol was followed by 47 international sites using the NEMA 2007/IEC 2008 PET body phantom with an 8-to-1 sphere-to-background ratio of 90Y solution. The phantom was imaged over a 7-day period (activity ranging from 0.5 to 3.0 GBq) and all reconstructed data were analysed at a core laboratory for consistent processing. Quantitative accuracy was assessed through measures of total phantom activity, activity concentration in background and hot spheres, misplaced counts in a nonradioactive insert, and background variability.
Results: Of the 69 scanners assessed, 37 had both time-of-flight (ToF) and resolution recovery (RR) capability. These current generation scanners from GE, Philips and Siemens could reconstruct background concentration measures to within 10 % of true values over the evaluated range, with greater deviations on the Philips systems at low count rates, and demonstrated typical partial volume effects on hot sphere recovery, which dominated spheres of diameter 20 mm in diameter, activity concentrations were consistently underestimated by about 20 %. Non-ToF scanners from GE Healthcare and Siemens were capable of producing accurate measures, but with inferior quantitative recovery compared with ToF systems.
Conclusion: Current generation ToF scanners can consistently reconstruct 90Y activity concentrations, but they underestimate activity concentrations in small structures (≤37 mm diameter) within a warm background due to partial volume effects and constraints of the reconstruction algorithm. At the highest count rates investigated, measures of background concentration (about 300 kBq/ml) could be estimated on average to within 1 %, 5 % and 2 % for GE Healthcare (all-pass filter, RR + ToF), Philips (4i8s ToF) and Siemens (2i21s all-pass filter, RR + ToF) ToF systems, respectively. Over the range of activities investigated, comparable performance between GE Healthcare and Siemens ToF systems suggests suitability for quantitative analysis in a scenario analogous to that of postradioembolization imaging for treatment of liver cancer
Halothane‐induced liver injury in guinea‐pigs: Importance of cytochrome P450 enzyme activity and hepatic blood flow
No full textA multicentre comparison of quantitative 90Y PET/CT for dosimetric purposes after radioembolization with resin microspheres
No full textPurpose: To investigate and compare the quantitative accuracy of Y-90 imaging across different generation PET/CT scanners, for the purpose of dosimetry after radioembolization with resin microspheres.
Methods: A strict experimental and imaging protocol was followed by 47 international sites using the NEMA 2007/IEC 2008 PET body phantom with an 8-to-1 sphere-to-background ratio of Y-90 solution. The phantom was imaged over a 7-day period (activity ranging from 0.5 to 3.0 GBq) and all reconstructed data were analysed at a core laboratory for consistent processing. Quantitative accuracy was assessed through measures of total phantom activity, activity concentration in background and hot spheres, misplaced counts in a nonradioactive insert, and background variability.
Results: Of the 69 scanners assessed, 37 had both time-of-flight (ToF) and resolution recovery (RR) capability. These current generation scanners from GE, Philips and Siemens could reconstruct background concentration measures to within 10 % of true values over the evaluated range, with greater deviations on the Philips systems at low count rates, and demonstrated typical partial volume effects on hot sphere recovery, which dominated spheres of diameter 20 mm in diameter, activity concentrations were consistently underestimated by about 20 %. Non-ToF scanners from GE Healthcare and Siemens were capable of producing accurate measures, but with inferior quantitative recovery compared with ToF systems.
Conclusion: Current generation ToF scanners can consistently reconstruct Y-90 activity concentrations, but they underestimate activity concentrations in small structures (a parts per thousand currency sign37 mm diameter) within a warm background due to partial volume effects and constraints of the reconstruction algorithm. At the highest count rates investigated, measures of background concentration (about 300 kBq/ml) could be estimated on average to within 1 %, 5 % and 2 % for GE Healthcare (all-pass filter, RR + ToF), Philips (4i8s ToF) and Siemens (2i21s all-pass filter, RR + ToF) ToF systems, respectively. Over the range of activities investigated, comparable performance between GE Healthcare and Siemens ToF systems suggests suitability for quantitative analysis in a scenario analogous to that of postradioembolization imaging for treatment of liver cancer
