Calibration of a medical laser system
Sorri, Niklas (2023)
2023
Konetekniikan DI-ohjelma - Master's Programme in Mechanical Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2023-06-07
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202305306318
https://urn.fi/URN:NBN:fi:tuni-202305306318
Tiivistelmä
Lasers have made many kinds of new treatments possible, and new forms of treatment are constantly being investigated. In 2021, the market size of medical laser devices was roughly 3.5 billion USD, and it is growing rapidly. Medical devices also have some of the strictest regulations controlling their design and manufacture, and these regulations vary between regions. The underlying purpose of the regulations is to guarantee the safety and efficiency of medical devices. The topic of this thesis was limited to only consider the medical device regulations in place in the European Union, the regulations in other regions were not studied. The target company of this thesis is a global manufacturer of laser systems to various applications. The research problem of the thesis is "How to calibrate a medical laser device accurately and reliably?".
A constructive research approach was used as a framework for the study. The study consisted of three phases. The first phase was to identify all the requirements placed on the device. These requirements came from two sources, application requirements and regulatory requirements. The second phase was to form a calibration plan that would allow the finished device to fulfill all previously identified requirements. The third and final phase was to create a plan for the verification process that would make sure that all the requirements are definitely fulfilled. Three study methods, literature review, brainstorming, and deductive analysis were used to answer the research questions. Company internal documents were also studied during the literature review.
The thesis succeeded in collecting all the relevant requirements, the most important of which was the necessity of single fault safety. Plans for the calibration and verification processes were also formed. Unfortunately the processes could not be tested in action, because the device in question was not finished during the writing of this thesis. The most obvious topic for future research would thus be to test the planned processes and measurement methods and study their reliability and accuracy.
In conclusion, there are two critical factors for accurate and reliable calibration. The first is to understand the working principles of the components under calibration. The knowledge about the working principle helps to recognize all the important factors to consider in the control and measurement setup. The second factor is to follow good calibration and measurement practices. By doing so, the effects of any unnecessary variance and human errors in the process can be minimized.
A constructive research approach was used as a framework for the study. The study consisted of three phases. The first phase was to identify all the requirements placed on the device. These requirements came from two sources, application requirements and regulatory requirements. The second phase was to form a calibration plan that would allow the finished device to fulfill all previously identified requirements. The third and final phase was to create a plan for the verification process that would make sure that all the requirements are definitely fulfilled. Three study methods, literature review, brainstorming, and deductive analysis were used to answer the research questions. Company internal documents were also studied during the literature review.
The thesis succeeded in collecting all the relevant requirements, the most important of which was the necessity of single fault safety. Plans for the calibration and verification processes were also formed. Unfortunately the processes could not be tested in action, because the device in question was not finished during the writing of this thesis. The most obvious topic for future research would thus be to test the planned processes and measurement methods and study their reliability and accuracy.
In conclusion, there are two critical factors for accurate and reliable calibration. The first is to understand the working principles of the components under calibration. The knowledge about the working principle helps to recognize all the important factors to consider in the control and measurement setup. The second factor is to follow good calibration and measurement practices. By doing so, the effects of any unnecessary variance and human errors in the process can be minimized.