Functional near-infrared spectroscopy (fNIRS) allows non-invasive assessment of cortical activity during naturalistic tasks. This study aimed to compare cortical activation dynamics—specifically the latency (t_max) and amplitude (ΔoxyHb) of oxygenated haemoglobin changes—in passive observation and an interactive task using the Nefroball system. A total of 117 healthy adults performed two tasks involving rhythmic hand movements: a passive protocol and an interactive game-controlled condition. fNIRS recorded signals from the visual, parietal, motor, and prefrontal cortices of the left hemisphere. The Mann–Whitney test revealed significantly shorter t_max in all areas during the interactive task, suggesting faster recruitment of cortical networks. ΔoxyHb amplitude was significantly higher only in the visual cortex during the interactive task, indicating increased visual processing demand. No significant ΔoxyHb differences were observed in the motor, prefrontal, or parietal cortices. Weak but significant positive correlations were found between tmax and ΔoxyHb in the motor and prefrontal regions, but only in the passive condition. These findings support the notion that interactive tasks elicit faster, though not necessarily stronger, cortical responses. The results have potential implications for designing rehabilitation protocols and brain–computer interfaces involving visual–motor integration.

Introduction: Radiotherapy plays a prominent role in the multidisciplinary treatment of cancers. Despite new irradiation techniques, radiation-induced cardiotoxicity remains a leading cause of morbidity and mortality. Therefore, prognostic indicators of radiotherapy toxicity are essential. This study aimed to investigate the influence of applied radiotherapy on the pulse wave recording and thereby on cardiovascular health, as well as to assess whether high signal resolution (HSR) pulse oximetry could be used as a prognostic indicator of radiotherapy toxicity. Methods: A total of 19 patients treated with radiotherapy to the lung or left breast were analyzed. Pulse oximetry was performed on all eligible patients (before and after the administration of a radiation dose) using the PULS-HSR program, which increases the resolution of the pulse wave recording. Results: Among the analyzed variables, we found the total dose administered to the target, as well as the treatment duration, significantly positively correlated with the change in ventricle/aorta volume ratio. The ventricle/aorta volume ratio parameter is the ratio between the area under the HSR pulse wave generated by the contraction of the left ventricle until the aortic valve closes and the area of the HSR pulse wave responsible for expansion and contraction of the aorta. Conclusion: The pilot study indicates HSR pulse oximetry, especially the ventricle/aorta volume ratio parameter, as a potential prognostic indicator of toxicity from radiation for breast and lung cancers.

In radiotherapy, boluses ensure dose buildup at the skin and adapt to complex anatomy, requiring stable, well-conforming materials. This study aimed to investigate the effect of ionising radiation (70 Gy, 6 MV) on changes in the physicochemical properties of two materials used for 3D printing bolus materials for radiotherapy: acrylonitrile butadiene styrene ABS and thermoplastic copolyester TPC. Surface roughness, tribological parameters, hardness, dimensional stability, Fourier transform infrared spectra FTIR, and differential scanning calorimetry DSC data were assessed. After irradiation, small statistically significant changes in roughness parameters were observed for both materials, with ABS exhibiting greater surface degradation. In tribological tests, ABS demonstrated a decrease in the coefficient of friction by up to 70%, while TPC remained stable. FTIR spectra revealed changes characteristic of ABS degradation and oxidation processes (reduction in the intensity of butadiene bands, CH₂ shifts, and an increase in carbonyl bands). Subtle chemical stability and potential signs of cross-linking were observed for TPC. DSC confirmed no changes in TPC and a decrease in the glass transition temperature of ABS, which may suggest slight structural degradation. A slight increase in hardness was observed for ABS and TPC after irradiation, and minimal dimensional changes were observed only for ABS. Based on the data obtained, X-ray radiation affected the tested materials differently. Although both retain their function after exposure to therapeutic doses, TPC exhibits greater chemical and mechanical resistance. Combined with its greater flexibility, this may result in improved clinical adhesion and reproducibility during radiotherapy. Further studies will include analysis of adhesion and dose distribution (Part 2).