Cost Analysis of an Additive Manufacturing Laboratory for 3D Printed Anatomical Models in Orthopaedic Pre-Surgical Planning and Surgery.
Date
2023-03
Authors
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Journal ISSN
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Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: The primary problem to be investigated is the need to know how much the individual activities of the three-dimensional printing (3DP) production process contribute to the overall cost per patient. How much to quote internal orthopaedic surgeons before performing the 3DP production process is also unknown and the secondary problem to be investigated. Lastly, the tertiary problem to be investigated is the need to know how much samples 3D printed in different filaments would melt
or deform after being exposed to low-temperature ethylene oxide (EtO) or autoclave sterilisation. In the 3DP production process, the investigator used dedicated software packages to create virtual 3D anatomical models from patients’ anonymised computed tomography (CT) or magnetic resonance imaging (MRI) scans for Fused Filament Fabrication (FFF) 3DP (designated as simulation models) and EtO or autoclave sterilisation (designated as haptic maps). Afterwards, a cost estimation model was developed to estimate the direct cost per patient, which was validated by comparing
the cost estimates to the cost model results of three new patient cases. Furthermore, samples made from acrylonitrile butadiene styrene (ABS), nylon and polylactic acid (PLA) were sterilised by using low-temperature EtO and autoclave sterilisation. Thereafter, samples were measured with a digital vernier calliper to obtain postprinting and post-sterilisation linear measurements in metres (m). Results were expressed as means ± standard deviations for the total linear differences and absolute percentage errors.
In the cost model study, image segmentation and manufacturing costs contributed 31 % and 45 % to the direct cost per patient, respectively. The direct costs of two patient cases were overestimated by 61 % and 74 %, respectively. In conclusion, optimising the image segmentation and manufacturing times of the 3DP production process may make medical 3DP more viable for use in orthopaedic applications and reduce the direct cost per patient. Also, the cost model may not be accurate to estimate the direct cost per patient due to the overestimation of costs in the validation dataset.
In the dimensional accuracy testing study, ABS (-1,03E-5 ± 1,65E-4 m) and PLA (-1,01E-4 ± 4,62E-4 m) were the most affected by EtO sterilisation and shrunk in mean linear differences as opposed to nylon (6,43E-6 ± 2,08E-4 m). Furthermore, ABS (-2,52E-4 ± 1,28E-3 m) and PLA (-2,30E-4 ± 7,06E-4 m) were the most affected by autoclave sterilisation and shrunk more in mean linear differences as opposed to nylon (-4,20E-5 ± 2,96E-4 m). To conclude, nylon was preferred as a suitable material for both low-temperature EtO (preferably) and autoclave sterilisation to sterilise haptic maps. The primary problem to be investigated is the need to know how much the individual activities of the three-dimensional printing (3DP) production process contribute to the overall cost per patient. How much to quote internal orthopaedic surgeons before performing the 3DP production process is also unknown and the secondary problem to be investigated. Lastly, the tertiary problem to be investigated is the need to know how much samples 3D printed in different filaments would melt or deform after being exposed to low-temperature ethylene oxide (EtO) or autoclave
sterilisation. In the 3DP production process, the investigator used dedicated software packages to create virtual 3D anatomical models from patients’ anonymised computed tomography (CT) or magnetic resonance imaging (MRI) scans for Fused Filament Fabrication (FFF) 3DP (designated as simulation models) and EtO or autoclave sterilisation (designated as haptic maps). Afterwards, a cost estimation model was developed to estimate the direct cost per patient, which was validated by comparing the cost estimates to the cost model results of three new patient cases. Furthermore,
samples made from acrylonitrile butadiene styrene (ABS), nylon and polylactic acid (PLA) were sterilised by using low-temperature EtO and autoclave sterilisation. Thereafter, samples were measured with a digital vernier calliper to obtain postprinting and post-sterilisation linear measurements in metres (m). Results were expressed as means ± standard deviations for the total linear differences and absolute percentage errors.
In the cost model study, image segmentation and manufacturing costs contributed 31 % and 45 % to the direct cost per patient, respectively. The direct costs of two patient cases were overestimated by 61 % and 74 %, respectively. In conclusion, optimising the image segmentation and manufacturing times of the 3DP production process may make medical 3DP more viable for use in orthopaedic applications and reduce the direct cost per patient. Also, the cost model may not be accurate to estimate the direct cost per patient due to the overestimation of costs in the validation dataset.
In the dimensional accuracy testing study, ABS (-1,03E-5 ± 1,65E-4 m) and PLA (-1,01E-4 ± 4,62E-4 m) were the most affected by EtO sterilisation and shrunk in mean linear differences as opposed to nylon (6,43E-6 ± 2,08E-4 m). Furthermore, ABS (-2,52E-4 ± 1,28E-3 m) and PLA (-2,30E-4 ± 7,06E-4 m) were the most affected by autoclave sterilisation and shrunk more in mean linear differences as opposed to nylon (-4,20E-5 ± 2,96E-4 m). To conclude, nylon was preferred as a suitable material for both low-temperature EtO (preferably) and autoclave sterilisation to sterilise haptic maps.
AFRIKAANS OPSOMMING: Die primêre probleem wat ondersoek moet word, is die behoefte om te weet hoeveel die individuele aktiwiteite van die drie-dimensionele druk- (3D-druk) produksieproses tot die algehele koste per pasiënt bydra. Hoeveel om interne ortopediese chirurge te kwoteer voordat die 3D-druk-produksieproses uitgevoer word, is ook onbekend en die sekondêre probleem wat ondersoek moet word. Laastens is die tersiêre probleem wat ondersoek moet word die behoefte om te weet hoeveel monsters 3D-gedruk in verskillende filamente sal smelt of vervorm nadat dit aan lae temperatuur etileenoksied- (EtO) of outoklaafsterilisasie blootgestel is. In die 3D-druk-produksieproses het die ondersoeker toegewyde sagteware-pakkette gebruik om virtuele 3D-anatomiese modelle te skep vanaf pasiënte se geanonimiseerde rekenaartomografie- (CT) of magnetiese resonansbeelding- (MRI) skanderings vir gesmelte filamentvervaardiging (FFF) 3D-drukking (aangewys as simulasie-modelle) en EtO- of outoklaafsterilisasie (aangewys as haptiese kaarte). Daarna is ’n kosteberamingsmodel ontwikkel om die direkte koste per pasiënt te skat, wat gevalideer is deur die kosteberamings te vergelyk met die kostemodelresultate van drie nuwe pasiëntgevalle. Verder is monsters wat gemaak is van akrielnitril-butadieen-styreen (ABS), nylon en polimelksuur (PLA) gesteriliseer deur lae temperatuur EtO- en outoklaafsterilisasie te gebruik. Daarna is monsters met ’n digitale vernier gemeet om post-3D-drukking en post-sterilisasie lineêre metings in meter (m) te verkry. Resultate is as gemiddeldes ± standaardafwykings vir die totale lineêre verskille en absolute persentasie foute uitgedruk. In die kostemodelstudie het segmentasie en vervaardigingkoste, onderskeidelik, 31 % en 45 % tot die direkte koste per pasiënt bygedra. Die direkte koste van twee pasiëntgevalle is, onderskeidelik, met 61 % en 74 % oorskat. Ten slotte kan die optimalisering van die segmentasie en vervaardigingstye van die 3D-drukproduksieproses mediese 3D-drukking meer lewensvatbaar maak vir gebruik in ortopediese toepassings en die direkte koste per pasiënt verminder. Die kostemodel is moontlik ook nie akkuraat om die direkte koste per pasiënt te beraam nie as gevolg van die oorskatting van kostes in die valideringsdatastel. In die dimensionele akkuraatheidstoetsingstudie is ABS (-1,03E-5 ± 1,65E-4 m) en PLA (-1,01E-4 ± 4,62E-4 m) die meeste deur EtO-sterilisasie beïnvloed en het gekrimp in gemiddelde lineêre verskille in teenstelling met nylon (6,43E-6 ± 2,08E4 m). Verder is ABS (-2,52E-4 ± 1,28E-3 m) en PLA (-2,30E-4 ± 7,06E-4 m) die meeste deur outoklaafsterilisasie beïnvloed en het meer gekrimp in gemiddelde lineêre verskille in teenstelling met nylon (-4,20E-5 ± 2,96E-4 m). Ter afsluiting is nylon verkies as ’n geskikte materiaal vir beide lae temperatuur EtO- (verkieslik) en outoklaafsterilisasie om haptiese kaarte te steriliseer.
AFRIKAANS OPSOMMING: Die primêre probleem wat ondersoek moet word, is die behoefte om te weet hoeveel die individuele aktiwiteite van die drie-dimensionele druk- (3D-druk) produksieproses tot die algehele koste per pasiënt bydra. Hoeveel om interne ortopediese chirurge te kwoteer voordat die 3D-druk-produksieproses uitgevoer word, is ook onbekend en die sekondêre probleem wat ondersoek moet word. Laastens is die tersiêre probleem wat ondersoek moet word die behoefte om te weet hoeveel monsters 3D-gedruk in verskillende filamente sal smelt of vervorm nadat dit aan lae temperatuur etileenoksied- (EtO) of outoklaafsterilisasie blootgestel is. In die 3D-druk-produksieproses het die ondersoeker toegewyde sagteware-pakkette gebruik om virtuele 3D-anatomiese modelle te skep vanaf pasiënte se geanonimiseerde rekenaartomografie- (CT) of magnetiese resonansbeelding- (MRI) skanderings vir gesmelte filamentvervaardiging (FFF) 3D-drukking (aangewys as simulasie-modelle) en EtO- of outoklaafsterilisasie (aangewys as haptiese kaarte). Daarna is ’n kosteberamingsmodel ontwikkel om die direkte koste per pasiënt te skat, wat gevalideer is deur die kosteberamings te vergelyk met die kostemodelresultate van drie nuwe pasiëntgevalle. Verder is monsters wat gemaak is van akrielnitril-butadieen-styreen (ABS), nylon en polimelksuur (PLA) gesteriliseer deur lae temperatuur EtO- en outoklaafsterilisasie te gebruik. Daarna is monsters met ’n digitale vernier gemeet om post-3D-drukking en post-sterilisasie lineêre metings in meter (m) te verkry. Resultate is as gemiddeldes ± standaardafwykings vir die totale lineêre verskille en absolute persentasie foute uitgedruk. In die kostemodelstudie het segmentasie en vervaardigingkoste, onderskeidelik, 31 % en 45 % tot die direkte koste per pasiënt bygedra. Die direkte koste van twee pasiëntgevalle is, onderskeidelik, met 61 % en 74 % oorskat. Ten slotte kan die optimalisering van die segmentasie en vervaardigingstye van die 3D-drukproduksieproses mediese 3D-drukking meer lewensvatbaar maak vir gebruik in ortopediese toepassings en die direkte koste per pasiënt verminder. Die kostemodel is moontlik ook nie akkuraat om die direkte koste per pasiënt te beraam nie as gevolg van die oorskatting van kostes in die valideringsdatastel. In die dimensionele akkuraatheidstoetsingstudie is ABS (-1,03E-5 ± 1,65E-4 m) en PLA (-1,01E-4 ± 4,62E-4 m) die meeste deur EtO-sterilisasie beïnvloed en het gekrimp in gemiddelde lineêre verskille in teenstelling met nylon (6,43E-6 ± 2,08E4 m). Verder is ABS (-2,52E-4 ± 1,28E-3 m) en PLA (-2,30E-4 ± 7,06E-4 m) die meeste deur outoklaafsterilisasie beïnvloed en het meer gekrimp in gemiddelde lineêre verskille in teenstelling met nylon (-4,20E-5 ± 2,96E-4 m). Ter afsluiting is nylon verkies as ’n geskikte materiaal vir beide lae temperatuur EtO- (verkieslik) en outoklaafsterilisasie om haptiese kaarte te steriliseer.
Description
Thesis (MSc)--Stellenbosch University, 2023.