An application based on the analysis of thermograms to calculate the thermographic index for pain and swelling assessment

As the world's population ages, the prevalence of rheumatic diseases is increasing. These diseases are often diagnosed and monitored using imaging techniques such as infrared thermography. In this study, we developed an application to calculate the thermographic index (TI) in a series of thermograms. Such index is used in rheumatology as a complementary diagnostic tool to assess pain and swelling. We designed the application in MATLAB App Designer; an environment for creating applications with a graphical user interface. To evaluate the performance of the developed application, we calculated the TI of ten trigger points (anterior shoulder, sternum, posterior shoulder, upper back, lower back, elbow, lateral shoulder, elbow pit, knee, and back of the knee) in a series of thermal images from 37 healthy participants. Results of the average temperature varied between 31.35 (knee for women) and 33.92 (lateral shoulder for men) in °C and TIs were lower than 2 and the results in the knee region are consistent with those reported in previous studies due to only the TI in the knee is known. This study contributes to the literature with reference values for nine trigger points other than the knee. This app is easy to use and may be useful in future applications for disease detection or monitoring of its progression.

Assessing Muscle Fatigue in Multiple Sclerosis using the Sample Entropy of Electromyographic Signals: A Proof of Concept

Background

Multiple sclerosis (MS) is a progressive and neurodegenerative disease of the central nervous system. Its symptoms vary greatly, which makes its diagnosis complex, expensive, and time-consuming. One of its most prevalent symptoms is muscle fatigue. It occurs in about 92% of patients with MS (PwMS) and is defined as a decrease in maximal strength or energy production in response to contractile activity. This article aims to compare the behavior of a healthy control (HC) with that of a patient with MS before and after muscle fatigue.

Methods

For this purpose, a static baropodometric test and a dynamic electromyographic analysis are performed to calculate the area of the stabilometric ellipse, the remitting MS (RMS) value, and the sample entropy (SampEn) of the signals, as a proof of concept to explore the feasibility of this test in the muscle fatigue quantitative analysis; in addition, the statistical analysis was realized to verify the results.

Results

According to the results, the ellipse area increased in the presence of muscle fatigue, indicating a decrease in postural stability. Likewise, the RMS value increased in the MS patient and decreased in the HC subject and the opposite behavior in the SampEn was observed in the presence of muscle fatigue.

Conclusion

Thus, this study demonstrates that SampEn is a viable parameter to estimate muscle fatigue in PwMS and other neuromuscular diseases.

Facial thermal and blood perfusion patterns of human emotions: Proof-of-Concept

In this work, a preliminary study of proof-of-concept was conducted to evaluate the performance of the thermographic and blood perfusion data when emotions of positive and negative valence are applied, where the blood perfusion data are obtained from the thermographic data. The images were obtained for baseline, positive, and negative valence according to the protocol of the Geneva Affective Picture Database. Absolute and percentage differences of average values of the data between the valences and the baseline were calculated for different regions of interest (forehead, periorbital eyes, cheeks, nose and upper lips). For negative valence, a decrease in temperature and blood perfusion was observed in the regions of interest, and the effect was greater on the left side than on the right side. In positive valence, the temperature and blood perfusion increased in some cases, showing a complex pattern. The temperature and perfusion of the nose was reduced for both valences, which is indicative of the arousal dimension. The blood perfusion images were found to be greater contrast; the percentage differences in the blood perfusion images are greater than those obtained in thermographic images. Moreover, the blood perfusion images, and vasomotor answer are consistent, therefore, they can be a better biomarker than thermographic analysis in identifying emotions.

Estimation of blood and bone marrow doses of thyroid carcinoma patients treated with 131I through gamma spectrometry

¹³¹I therapy is the treatment for patients with differentiated thyroid carcinoma (DTC) to ablate remnant thyroid tissue after surgery. The aim of this study was to estimate the absorbed doses to the blood and bone marrow of patients with DTC using gamma spectrometry. The evaluation of the absorbed dose in blood and bone marrow is a good indicator of a patient's response and its radiological protection. The average of low activities administered (AAAL) to ten patients was 3.20 GBq and the average of high activities administered (AAAH) to eight patients was 4.95 GBq. The blood and bone marrow doses were determined according to Lassmann et al 2008, performing successive measurements of activity in blood samples and whole body. Blood samples of 2 ml were taken during the first 48 h; the first one was extracted 2 h after the administration of the capsule and the following ones were taken every 12 h. The whole-body measurements were made at regular intervals of time throughout the patient's isolation period using a mobile gamma spectrometry system located inside the isolation room of the Dr Hernán Henríquez Aravena Hospital. The average residence times in blood and whole-body were (6.9 ± 1.7) × 10^-4 h ml^-1 and (23.2 ± 4.5) h, respectively. The average doses in blood and bone marrow of patients with AAAL were (0.33 ± 0.09) Gy and (0.63 ± 0.18) Gy, respectively, and with AAAH were (0.48 ± 0.06) Gy and (0.87 ± 0.19) Gy, respectively. In all studied patients, the bone marrow doses were less than 2 Gy. The results were compared with the previously published values, finding some differences between the residence times and significant differences in the doses, which show the need to compare the different methodologies.

DEVELOPMENT AND IMPLEMENTATION OF TOOLS FOR SELF-MONITORING OF STAFF EXPOSED TO 131I IN NUCLEAR MEDICINE CENTRES OF CHILE

Currently in Chile, there are about 42 nuclear medicine centres that mainly use 99mTc and 131I in diagnostic and therapeutic procedures. Therefore, staff performs various tasks that increase the risk of internal incorporation and the need to implement routine monitoring programmes. This article shows tools for self-monitoring of staff who exposed to 131I from measurements in thyroid and urine samples, using the gamma cameras of Nuclear Medicine Units. Then, the calibration factors of gamma cameras of participating units were determined, and a one-worker dose was calculated due to internal incorporation, using an Excel spreadsheet for self-monitoring. The worker who handles 131I in one of the studied units was monitored for 6 months. The goal of this study is to implement a routine self-monitoring programme for the estimation of committed effective dose of staff exposed to 131I using gamma cameras in Nuclear Medicine Units of clinical centres in Chile.