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This study aimed to investigate the effects of auditory stimulation with different frequency variations (increasing, decreasing, and constant) on performance, physiological parameters and perceived exertion in the shuttle run test. Twenty-four healthy sports science students participated in this experimental study and performed the shuttle run test under four different conditions: a) standard (as baseline); b) auditory stimulation with increasing frequency; c) auditory stimulation with decreasing frequency; and d) auditory stimulation with constant frequency. The results showed that maximal oxygen consumption in the decreasing-frequency condition was significantly higher than in any other condition and performance in the increasing-frequency condition was higher than that in the constant and standard conditions. The results also showed that in the initial and intermediate phases of the test, heart rate and perceived exertion were lower in both the increasing– and decreasing– frequency conditions than in the constant frequency and standard conditions. The results of the present study suggest that the use of auditory stimulation with decreasing frequency and increasing frequency can improve performance in endurance tasks. Future studies should better understand the different effects of these two types of stimulation and investigate whether they lead to long-term improvements. [ABSTRACT FROM AUTHOR]

Context: Pulse oximetry is one of the most revolutionary methods used to monitor the patients in the clinical setting, particularly intensive care and anesthesia. We usually use the index or middle finger to measure SpO2 values, but little is known about the inter-digital differences that exist between the fingers. Aim: We aim to compare the peripheral capillary oxygen saturation among fingers of both hands. A total of 93 healthy volunteers aged between 18 and 50 years participated in the study. Materials and Methods: Their SpO2 values were recorded from each finger with at least 1 minute of resting interval. Their blood pressure, heart rate, and body temperature were recorded as well. Result: A total of 930 measurements were obtained from 93 volunteers. The highest average SpO2 value of right-handed volunteers was measured from the left little finger (98.48 ± 0.62) of right-handed volunteers, and it was statistically significant when compared with the right ring finger, right little finger, left thumb, left index, left middle finger, and left ring finger. The highest average SpO2 from left-handed volunteers was obtained from the right index finger, but it was statistically insignificant. Conclusion: We assume ethnic and climatic differences to play a role in contradictory results noted from previous studies conducted, and this needs to be investigated further. It is recommended that multiple readings may be obtained from other fingers as well before coming to any conclusion as inter-finger variability cannot be ignored.

Context: Pulse oximetry is one of the most revolutionary methods used to monitor the patients in the clinical setting, particularly intensive care and anesthesia. We usually use the index or middle finger to measure SpO2 values, but little is known about the inter-digital differences that exist between the fingers. Aim: We aim to compare the peripheral capillary oxygen saturation among fingers of both hands. A total of 93 healthy volunteers aged between 18 and 50 years participated in the study. Materials and Methods: Their SpO2 values were recorded from each finger with at least 1 minute of resting interval. Their blood pressure, heart rate, and body temperature were recorded as well. Result: A total of 930 measurements were obtained from 93 volunteers. The highest average SpO2 value of right-handed volunteers was measured from the left little finger (98.48 ± 0.62) of right-handed volunteers, and it was statistically significant when compared with the right ring finger, right little finger, left thumb, left index, left middle finger, and left ring finger. The highest average SpO2 from left-handed volunteers was obtained from the right index finger, but it was statistically insignificant. Conclusion: We assume ethnic and climatic differences to play a role in contradictory results noted from previous studies conducted, and this needs to be investigated further. It is recommended that multiple readings may be obtained from other fingers as well before coming to any conclusion as inter-finger variability cannot be ignored. [ABSTRACT FROM AUTHOR]

Wearable sensors are emerging as a new technology to detect physiological and biochemical markers for remote health monitoring. By measuring vital signs such as respiratory rate, body temperature, and blood oxygen level, wearable sensors offer tremendous potential for the noninvasive and early diagnosis of numerous diseases such as Covid‐19. Over the past decade, significant progress has been made to develop wearable sensors with high sensitivity, accuracy, flexibility, and stretchability, bringing to reality a new paradigm of remote health monitoring. In this review paper, the latest advances in wearable sensor systems that can measure vital signs at an accuracy level matching those of point‐of‐care tests are presented. In particular, the focus of this review is placed on wearable sensors for measuring respiratory behavior, body temperature, and blood oxygen level, which are identified as the critical signals for diagnosing and monitoring Covid‐19. Various designs based on different materials and working mechanisms are summarized. This review is concluded by identifying the remaining challenges and future opportunities for this emerging field. [ABSTRACT FROM AUTHOR]

Advances in several engineering fields have led to a trend toward miniaturization and portability of wearable biosensing devices, which used to be confined to large tools and clinical settings. Various systems to continuously measure electrophysiological activity through electrical and optical methods are one category of such devices. Being wearable and intended for prolonged use, the amount of noise introduced on sensors by movement remains a challenge and requires further optimization. User movement causes motion artifacts that alter the overall quality of the signals obtained, hence corrupting the resulting measurements. This paper introduces a fully wearable optical biosensing system to continuously measure pulse oximetry and heart rate, utilizing a reflectance-based probe. Furthermore, a novel data-dependent motion artifact tailoring algorithm is implemented to eliminate noisy data due to the motion artifact and measure oxygenation level with high accuracy in real time. By taking advantages of current wireless transmission and signal processing technologies, the developed wearable photoplethysmography device successfully captures the measured signals and sends them wirelessly to a mobile device for signal processing in real time. After applying motion artifact tailoring, evaluating accuracy with a continuous clinical device, the blood oxygenation measurements obtained from our system yielded an accuracy of at least 98%, when compared to a range of 93.6%–96.7% observed before from the same initial data. Additionally, heart rate accuracy above 97% was achieved. Motion artifact tailoring and removal in real time, continuous systems will allow wearable devices to be truly wearable and a reliable electrophysiological monitoring and diagnostics tool for everyday use. [ABSTRACT FROM AUTHOR]

Ultrasound contrast agents (UCA) are gas-encapsulated microspheres that oscillate volumetrically when exposed to an ultrasound field producing backscattered signals efficiently, which can be used for improved ultrasound imaging and drug delivery applications. We developed a novel oxygen-sensitive hemoglobin-shell microbubble designed to acoustically detect blood oxygen levels. We hypothesize that structural change in hemoglobin caused due to varying oxygen levels in the body can lead to mechanical changes in the shell of the UCA. This can produce detectable changes in the acoustic response that can be used for measuring oxygen levels in the body. In this study, we have shown that oxygenated hemoglobin microbubbles can be differentiated from deoxygenated hemoglobin microbubbles using a 1D convolutional neural network using radiofrequency (RF) data. We were able to classify RF data from oxygenated and deoxygenated hemoglobin microbubbles into the two classes with a testing accuracy of 90.15%. The results suggest that oxygen content in hemoglobin affects the acoustical response and may be used for determining oxygen levels and thus could open many applications, including evaluating hypoxic regions in tumors and the brain, among other blood-oxygen-level-dependent imaging applications.

Context: Pulse oximetry is one of the most revolutionary methods used to monitor the patients in the clinical setting, particularly intensive care and anesthesia. We usually use the index or middle finger to measure SpO 2 values, but little is known about the inter-digital differences that exist between the fingers., Aim: We aim to compare the peripheral capillary oxygen saturation among fingers of both hands. A total of 93 healthy volunteers aged between 18 and 50 years participated in the study., Materials and Methods: Their SpO 2 values were recorded from each finger with at least 1 minute of resting interval. Their blood pressure, heart rate, and body temperature were recorded as well., Result: A total of 930 measurements were obtained from 93 volunteers. The highest average SpO 2 value of right-handed volunteers was measured from the left little finger (98.48 ± 0.62) of right-handed volunteers, and it was statistically significant when compared with the right ring finger, right little finger, left thumb, left index, left middle finger, and left ring finger. The highest average SpO 2 from left-handed volunteers was obtained from the right index finger, but it was statistically insignificant., Conclusion: We assume ethnic and climatic differences to play a role in contradictory results noted from previous studies conducted, and this needs to be investigated further. It is recommended that multiple readings may be obtained from other fingers as well before coming to any conclusion as inter-finger variability cannot be ignored., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Journal of Family Medicine and Primary Care.)

In a multidimensional feature space, the snoring sounds can extend from a very compact cluster to highly distinct clusters. In this study, we investigated the cause of snoring sound's variation within the snorers. It is known that a change in body position and sleep stage can affect snoring during sleep but it is unclear whether positional, sleep state, and blood oxygen level variations cause the snoring sounds to have different characteristics, and if it does how significant that effect would be. We extracted 12 characteristic features from snoring sound segments of 57 snorers and transformed them into a 4-D feature space using principal component analysis (PCA). Then, they were grouped based on the body position (side, supine, and prone), sleep stage (NREM, REM, and Arousal), and blood oxygen level (Normal and Desaturation). The probability density function of the transformed features was calculated for each class of categorical variables. The distance between the class-densities were calculated to determine which of these parameters affects the snoring sounds significantly. Analysis of Variance (ANOVA) was run for each categorical variable. The results show that the positional change has the highest effect on the snoring sounds; it results in forming distinct clusters of snoring sounds. Also, sleep state and blood oxygen level variation have been found to moderately affect the snoring sounds. [ABSTRACT FROM AUTHOR]

The grown interest in healthcare applications has made biomedical engineering one of the fastest growing disciplines in recent years. Photoplethysmography (PPG) has gained popularity in recent years due to its versatility for noninvasive monitoring of vital signs such as heart rate, respiratory rate, blood oxygen saturation and blood pressure. In this work, an adjustable PPG-based educational device called PPG EduKit, which aims to facilitate the learning of the PPG technology for a wide range of engineering and medical disciplines is proposed. Through the use of this educational platform, the PPG signal can be understood, modified and implemented along with the extraction of its relevant physiological information from a didactic, intuitive and practical way. The PPG Edukit is evaluated for the extraction of physiological parameters such as heart rate and blood oxygen level, demonstrating how its features contribute to engineering and medical students to assimilate technical concepts in electrical circuits, biomedical instrumentation, and human physiology. [ABSTRACT FROM AUTHOR]

Abstract: This fMRI study investigates the activation of the thalamic nuclei in a spatial focusing-of-attention task previously shown to activate the pulvinar with FDG-PET and assesses the connectivity of the thalamic nuclei with cortical areas. Normal right-handed subjects (eight men, eight women, average age=32 years) viewed four types of stimuli positioned to the right or left of the central fixation point (left hemifield-large letter, left hemifield-small letter display with flanking letters; right hemifield-large letter, right hemifield-small letter display with flankers). BOLD responses to small letters surrounded by flankers were compared with responses to large isolated letters. To examine maximum functional regional connectivity, we modeled “subject” as a random effect and attained fixed effect parameter estimates and t-statistics for functional connectivity between each of the thalamic nuclei (pulvinar, medial dorsal, and anterior) as the seed region and each non-seed voxel. Greater BOLD activation for letters surrounded by flankers than for large letters was observed in the pulvinar as anticipated and was also marked in the medial dorsal nucleus (MDN), anterior and superior cingulate (BA24 and BA24′), dorsolateral prefrontal cortex, and frontal operculum and insula. For the MDN, maximal functional connectivity was with the dorsolateral prefrontal cortex; correlations with left superior temporal, parietal, posterior frontal, and occipital regions were also observed. For the pulvinar, maximal functional connectivity was with parietal BA39; for anterior thalamus, with anterior cingulate. [Copyright &y& Elsevier]