An infrared-based device for non-invasive monitoring of eyelid movement during sleep

The increased movement of eyes and eyelids is characteristic of the rapid eye movement (REM) sleep stage, making it an important indicator in sleep monitoring. A device was designed to detect this activity in a non-invasive way by means of measuring infrared light intensity reflected off the eyelid. The system converts the light intensity into current through a photodetector, performs analog signal processing and analog to digital conversion (ADC). The data is transmitted wirelessly to a computer, where the results can be displayed, stored and analyzed with a dedicated software, which also provides control over the device. The hardware is embedded in a mask, which is put over the patient's eyes. User safety in terms of mechanical, electrical and optical dangers has been ensured. The device was tested on a napping subject.

Testy podstawowe monitorów stosowanych do prezentacji obrazów medycznych

Coraz powszechniej klisza rentgenowska jest wypierana przez detektory cyfrowe. Obraz zapisany w postaci cyfrowej jest następnie prezentowany z użyciem monitorow, zwykle diagnostycznych. W niniejszym dokumencie przedstawiono zestaw testow, ktore zdaniem Polskiego Towarzystwa Fizyki Medycznej, powinny być wykonywane dla monitorow używanych do prezentowania obrazu zapisanego w postaci cyfrowej. Dokument ten powstał z inicjatywy Zarządu Głownego Polskiego Towarzystwa Fizyki Medycznej, został opracowany na podstawie dostępnych publikacji przez fizykow z Zakładu Fizyki Medycznej Centrum Onkologii w Warszawie we wspołpracy z zespołem konsultantow powołanych przez Zarząd Głowny PTFM.

Testy specjalistyczne monitorów stosowanych do prezentacji obrazów medycznych

W opracowaniu przedstawiono zestaw testow, ktore zdaniem Polskiego Towarzystwa Fizyki Medycznej, powinny być wykonywane dla monitorow używanych do prezentowania obrazu zapisanego w postaci cyfrowej. Dokument ten powstał z inicjatywy Zarządu Głownego Polskiego Towarzystwa Fizyki Medycznej, został opracowany na podstawie dostępnych publikacji przez fizykow z Zakładu Fizyki Medycznej Centrum Onkologii w Warszawie we wspołpracy z zespołem konsultantow powołanych przez Zarząd Głowny PTFM.

Testy specjalistyczne w mammografii z detektorem filmowym

W opracowaniu przedstawiono zestaw testow specjalistycznych, ktore zdaniem Polskiego Towarzystwa Fizyki Medycznej, powinny być wykonywane w mammografii z detektorem filmowym. Dokument ten powstał z inicjatywy Zarządu Głownego Polskiego Towarzystwa Fizyki Medycznej i został opracowany, na podstawie dostępnych publikacji oraz obowiązującego prawa, przez fizykow z Zakładu Fizyki Medycznej Centrum Onkologii w Warszawie we wspołpracy z zespołem konsultantow powołanych przez Zarząd Głowny PTFM.

Assessment of occupational internal exposure to beta emitters from the nuclear reactor primary coolant circuit

Fission products of 235U or isotopes from activation may appear in technological waters at normal operation of a research reactor. Therefore, reactor cooling water may contain a number of beta radioactive isotopes including yttrium and strontium isotopes, which can pose potential hazard to reactor personnel. In order to asses internal exposure urinalysis is carried out. This work presents the method of sample preparation and measurement used by Radiation Protection Measurements Laboratory (RPLM) of the National Centre for Nuclear Research (NCNR). Method of various isotopes of yttrium and Sr-90 activity calculation is also shown. Determination of these isotopes activities in urine sample allows estimating the effective doses

Numerical model of detector for in vivo internal dosimetry in radiological incidents

The aim of this work was to create a numerical model of scintillation detector and to check whether such detector can be used for the measurements of internal contamination in emergency conditions. The purpose of the measurements would be only detection of possible contamination, without identification of radioactive isotopes, and hence without estimation of effective dose. However, in emergency conditions, it is sufficient for the rapid selection of a group of contaminated persons, who should be subjected to careful inspection in the laboratory conditions. The calculations were performed for three detector positions relatively to the phantom. The distribution of dose rate was also calculated, in order to find the best geometry for dose rate measurements around human body. Another problem under consideration was the possible influence of radioactive contamination in the environment on the registration of the gamma spectrum emitted from the whole body phantom. Performed calculations showed that there is a possibility to measure internal contamination outside laboratory, even in contaminated area.

Theoretical Modelling of Alveolar Resonance Mechanism of Ultrasound-Induced Lung Haemorrhage

The possibility of the ultrasound-induced lung haemorrhage occurring in adult human during diagnostic ultrasound examination is studied here. This study is based on the hypothetical alveolar resonance mechanism of the ultrasound-induced lung haemorrhage. The alveolar wall is initially modelled here as a square membrane with fixed-boundary, and then theoretically subjected to vibration analysis. The equation of threshold pressure for the occurrence of ultrasound-induced lung haemorrhage is derived. A comparison test against past experimental data validates the use of the square membrane model of the alveolar wall in studying the ultrasound induced lung haemorrhage. This study predicts that the ultrasound-induced lung haemorrhage in adult human can be prevented if the ultrasound frequency is kept above 1.69 MHz while the Mechanical Index does not exceed 1.9.

Intensity modulated radiotherapy using Monte Carlo for routine postmastectomy radiotherapy

Radiotherapy given after mastectomy (PMRT) will reduce the risk of local recurrence by about two-thirds. Clinical and dosimetric trials were carried out using various techniques to optimize the treatments by maximizing the dose to the tumour and minimizing it to the healthy tissues at proximity. Different conventional techniques which have been studied suffer from important dose inhomogeneities due to the complex anatomy of the chest, which reduces the benefits from such treatments. Moreover, due to the heterogeneity of breast cancer, the response to therapy and a systematic approach to treatment cannot be derived and treatment regimens must be determined on a patient-by-patient basis. This is only possible if accurate and fast treatment planning systems are available. Intensity Modulated Radiotherapy (IMRT) allows delivering higher doses to the target volume and limits the doses to the surrounding tissues. The objective of this study is to test the feasibility of applying a Monte Carlo-based treatment planning system, Hyperion accurately in routine Intensity Modulated Radiotherapy (IMRT) postmastectomy. In order to use a treatment planning system for routine work it should prove to provide optimized dose delivery in a suitable time. Treatment planning for IMRT application to PMRT was performed using Hyperion. Constraints were set to deliver the prescribed dose to the target and minimize the dose to the organs at risk. Dose Volume Histograms (DVH) were used to evaluate the set up plans. Time taken to optimize the plan was measured. The target coverage was within the accepted values. Approximately 90% of the breast and 80% of the PTV received 45 Gy or above. The volume of the lung that received 40Gy was less than 10% and the volume that received 20Gy (V20) was less than 25%. The volume of the heart receiving 30 Gy (V30) or above was negligible. This indicates low NTCP of these organs. The time taken for optimization, showed it possible to apply Monte Carlo-based treatment-planning systems for patient-to-patient PMRT.

Measurements of high level of iodine activity in thyroid with different radiation meters

Iodine activity in thyroid of female patient was measured with different radiation meters in order to estimate a possibility to use them in case of radiation accident. Two series of measurements were performed - first after diagnostic and second after therapeutic administration of iodine to the patient. The isotope activities were higher than those registered during routine radiation monitoring and similar to the activities which could be registered after radiation accident. The studies showed that simple dose rate meters may serve for identification and selection of contaminated persons which should be later subjected to the measurements with especially dedicated equipment. The initial measurements can be performed outside laboratory.

Development of a method of exposed characteristic points in activity pattern for rat behaviour classification

A fast method for visual inspection and classification of massive locomotor activity data registered from laboratory rats is presented. Positions in the home cage of one hundred rats have been constantly recorded during 90 day period using photodiodes and beam crossing method with use of custom build system. Direct inspection and comparison of classic form of actograms did not bring information for fast and easy recognition of anomalies in daily behavioural cycle. A method of obtaining fast and easy to compare locomotor activity pattern is presented. The key point of proposed method is exposition of characteristic points in the activity diagram. About 9000 actograms were inspected and classified for investigation with use of ANOVA.