Characterization and Calibration Setup for a Medical Laser System
Hurskainen, Matius (2020)
2020
Sähkötekniikan DI-tutkinto-ohjelma - Degree Programme in Electrical Engineering, MSc (Tech)
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2020-05-25
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202005205507
https://urn.fi/URN:NBN:fi:tuni-202005205507
Tiivistelmä
Laser devices and systems have become increasingly important in industrial, medical and consumer electronic applications. In the near future, the demand of solutions such as facial recognition and automotive rangefinders will increase. Research in microprocessor technology and quantum computing on the other hand suggests of entirely new kind of requirements in the coming years.
One of the most rapidly growing branches of laser technology are medical devices. Applications in this field include, among many others, tattoo removal, brain surgery, diagnosis of disease, ophthalmic instruments and cancer treatment.
The tasks of this work is the development of methods and equipment for characterization and calibration of an ophthalmic, medical laser system. The aim is to both enable safe and reliable operation of this product, as well as to allow for seamless replacement of either of the system's key components. Such a setup has not yet existed, and developing one is crucial for enabling effective and repeatable manufacturing of the product.
In this work, laser fundamentals and electrical characteristics are explored and regulatory challenges posed by the intended use of medical purposes are discussed. Further properties related to laser systems and actual driving of laser diodes, as well as the need for accompanying electronics are in turn analyzed.
The structure of the actual laser system and necessary characterization and calibration processes are identified. This includes the requirements for the accuracies of said processes, in order to make sure the target parameters for the laser system are met, even if either of the system's components is replaced.
This functionality is found to require characterization of the laser system's measurement electronics. To validate the chosen methods for characterizing these components, a test apparatus is designed and built. Initial testing with this appliance and other laboratory equipment indicates the suitability of the chosen methods and electronic solutions for the purpose.
Based on these promising results, an automated characterization setup is designed and built to replace the test apparatus. This new setup is based around an embedded computer, with several additional components and dedicated software. The solution is then used for final testing of two laser systems.
Due to incomplete product firmware, verification of photodiode current measurement was not possible. However, the targets for laser irradiances, as well as spot size measurements were all achieved.
One of the most rapidly growing branches of laser technology are medical devices. Applications in this field include, among many others, tattoo removal, brain surgery, diagnosis of disease, ophthalmic instruments and cancer treatment.
The tasks of this work is the development of methods and equipment for characterization and calibration of an ophthalmic, medical laser system. The aim is to both enable safe and reliable operation of this product, as well as to allow for seamless replacement of either of the system's key components. Such a setup has not yet existed, and developing one is crucial for enabling effective and repeatable manufacturing of the product.
In this work, laser fundamentals and electrical characteristics are explored and regulatory challenges posed by the intended use of medical purposes are discussed. Further properties related to laser systems and actual driving of laser diodes, as well as the need for accompanying electronics are in turn analyzed.
The structure of the actual laser system and necessary characterization and calibration processes are identified. This includes the requirements for the accuracies of said processes, in order to make sure the target parameters for the laser system are met, even if either of the system's components is replaced.
This functionality is found to require characterization of the laser system's measurement electronics. To validate the chosen methods for characterizing these components, a test apparatus is designed and built. Initial testing with this appliance and other laboratory equipment indicates the suitability of the chosen methods and electronic solutions for the purpose.
Based on these promising results, an automated characterization setup is designed and built to replace the test apparatus. This new setup is based around an embedded computer, with several additional components and dedicated software. The solution is then used for final testing of two laser systems.
Due to incomplete product firmware, verification of photodiode current measurement was not possible. However, the targets for laser irradiances, as well as spot size measurements were all achieved.