Project title:

"Development of prototype devices for non-invasive skin condition assessment"

Project contract number:

Project partners:

Tallinn Technical University.

Project implementation deadline:

01.01.2018 - 31.12.2020

Total project funding:

133 806.00 EUR

ERAF funding: 113 735.10 EUR

State budget financing:  13 380.60 EUR

UL funding: 6 690.30 EUR

Research manager:

Edgars Kviesis-Kipge (Biofotonikas laboratorija)

Aim of the project:

To develop new technological medical prototype devices for analysis, evaluation and monitoring of human skin formations.

Project results:

scientific publications – 3, conference abstracts – 4, international mobility – 1, IAPS UL seminar – 3, an advanced prototype of a skin cancer and chromophore mapping device has been developed – 1, developed and laboratory tested functional prototype device for skin chromophore mapping using laser lighting – 1, developed and tested a prototype of a contactless PPG signal recording device – 1.

01.01.2018 – 31.03.2018

Worked on the development and improvement of the multispectral device Skimager according to the project. A new Skimager LED ring has been created - I have performed measurements of the radiation stability of the previously developed LED ring. The results were different for each wavelength, with a tendency to decrease in intensity during the first five seconds. The main difference will be that the new one will be made of 1.5mm aluminum plate. This would significantly improve the thermal output from the LEDs. A technically complex design work has been performed to develop such an diode aluminum ring.
Skimager body - worked on body improvements.
Work has been done on supplementing the Skimager electronics board - all nodes of the developed circuit boards have been tested and the revealed shortcomings have been accounted for and improvements have been made. Various nodes are changed and the board drawing is improved.
Skimager software enhancements - Compilation of required SkImager enhancements, research of Windows Embedded Compact 7, test run and research of camera example code. SkImager RAW image programming research and RAW image preparation for Matlab research.
Submitted: Uldis Rubins, Zbignevs Marcinkevics, Janis Cimurs, Andris Grabovskis, Edgars Kviesis-Kipge, Univ. of Latvia (Latvia) “Snapshot hyperspectral system for non-invasive skin blood oxygen saturation monitoring”, Paper No.10685-143. Submission date 3/30/2018, conference SPIE Photonics Europe.

01.04.2018 - 30.06.2018

Worked on the development and improvement of the multispectral device Skimager according to the project. I have performed measurements of the radiation intensity stability of the developed LED ring. Work has begun on improvements to the Skimager hull. Improved device battery charging connector. Worked on creating a device switching mechanism. The part of the housing with the power button, USB socket and memory card slot was manufactured and tested. Written and submitted conference thesis: Edgars Kviesis-Kipge, Uldis Rubīns “Remote imaging photoplethysmography device for palm microcirculation assessment”. Optimization and improvement of the electronic circuit of the multispectral device “Skimager” has been performed. Its heat transfer, temperature regime and stability of light intensity over time were tested. The uniformity of UV diode radiation intensity was studied separately, which led to the conclusion that the optical circuit of the device should be supplemented with feedback in order to obtain stable radiation. As a result, the publication Edgars Kviesis-Kipge, Uldis Rubīns, Oskars Rubenis “Multimodal imaging device for skin diagnostics: improvements and tests” was written.

01.07.2018 - 30.09.2018

Worked on drawing the electronic board of the multispectral device "Skimager".
Participation in the conference Northern Optics & Photonics 2018, which took place in Lund, Sweden, 12-14. September, which presents the prototype improvements of the non-contact blood circulation microcirculation device performed during the Postdoctoral Project. Participation in the science popularization event "Scientists' Night 2018".

01.10.2018 - 31.12.2018

I participated in the Baltic Electronics Conference, which took place in Tallinn, Estonia, from October 8 to 10, where I presented the technical solutions and results of the multimodal diagnostic prototype device “Skimager” developed during the Postdoctoral Research Project. The written publication will be placed in the digital database of
Worked on the parts of the device housing, clarified the drawing, supplemented with elements such as the location of the polarizing ring in the housing and its stable fixing in place. The body connection parts have been specified so that it is firmly held together. Several improved drawing assemblies were printed, which were printed on a 3D prototyping printer available at IAPS UL.
A drawing of the device body has been prepared for professional 3D printing. Worked on the finishing of the case. As a result, a new technically improved prototype skin formation diagnostic device has been created.

01.01.2019 - 31.03.2019

Work has begun on the concept development of the second prototype laser device envisaged in the project. Worked on the study of specific technical parameters of laser diodes (radiation power, size of laser diode and symmetry of outputs, radiation profile and its width). As a result, the researched laser diodes, which corresponded to the parameters of the device planned to be created in the project, will be purchased and installed in the device.
I studied the electronic circuits of laser diode control, which are necessary for the creation of the device. The study uses Internet resources from the largest and most popular electronic component manufacturers. The resulting information was used to design the electronic circuit. A circuit has been created that will ensure the stabilization of the laser diode current and even radiation intensity over time. I am also working on drawing the electronic board of this circuit.
II studied the solution of the laser smear "smearing" scheme. It is based on a moving electromechanical element, usually a miniature speaker connected to a signal generator. The resulting signal with a frequency of ~ 500Hz vibrates the speaker and this in turn moves a small diffuser. As a result, the unevenness caused by laser diode radiation is masked, which is also the expected result. Schematic solutions for signal generator power stage development were studied. A design solution for the newly developed prototype device was planned, which would ensure the compatibility of the housing with the prototype of the diagnostic multimodal device Skimager developed in the previous period. The best locations of the laser control circuit in the front part of the housing were studied.

01.04.2019 - 30.06.2019

I continued technical and literature research on prototype devices for skin chromophore mapping using laser lighting. As a result of the research, a drawing of a ring-shaped plate on which twenty laser diodes are placed is created. They are arranged in four groups of five diodes. I place them in specific positions based on laboratory research on the even distribution of radiation. A conference thesis entitled “Development of skin chromophore mapping device using five spectral line illumination” has been written and approved. The thesis was confirmed as an oral presentation. I continued to work on the concept development and testing of the laser device under laboratory conditions. As a result, I developed and tested a laser diode power control circuit. I researched laser power control circuit output voltage filtering solutions. Due to the fact that lasers are very sensitive to overvoltages, static voltages and pulses, I have created a filter that reduces all the shortcomings listed. I am also working on researching the laser diode control circuit and ensuring uniform radiation with the help of diffusers. I attended the Imaging and Applied Optics conference 2019. I gave an oral presentation in Imaging Systems and Applications and presented the results of a diagnostic device developed in a postdoctoral research project called line lights). I presented the work done in the postdoctoral project at the IAPS UL seminar.

01.07.2019 - 30.09.2019

Engineering research work has been carried out working on a prototype device for mapping skin chromophores using laser lighting. I studied the technical literature on laser control parameters and current regulation. Before creating and testing the circuit module responsible for providing stable laser radiation, I discovered that the output of a given circuit has a high noise level. As lasers are very sensitive to voltage and current surges generated by a noisy signal, I decided not to risk lasers and develop an improved schematic solution. With a lot of time, such a scheme was created. I also developed a drawing of the electronic board, which I plan to make and test in the near future. I am also working on the development of the visual design of the prototype device housing.
Participation in the Scientists' Night event, presented an advanced prototype of the Skimager skin diagnostic multimodal device in a postdoctoral project.

01.10.2019 - 31.12.2019

Work on a prototype device for mapping skin chromophores using laser lighting for the main control circuit soldering and testing of all electronic components. Fixed and soldered laser diode ring plate, which revealed a deviation from the optical axis. Laser control scheme completed and tested. The development of a new control circuit has eliminated previous shortcomings (increased output noise level and on / off peak voltage and current peak, which can damage the lasers). Calibration of electronic components required to provide laser supply voltages has been performed. Tested laser electronic board drawing, board made and soldered. Usage pre-selected, tested lasers that match the wavelength of the radiation. Work on the 3D drawing of the prototype device housing has been completed. Improved front part of the housing, where the laser ring and its control board are mounted. The housing incorporates a miniature electromechanical element for leveling laser beams. The body is made and all post-treatment processes are performed (cleaning, polishing and priming of all body surfaces). Components are assembled in the housing.