scholarly journals Derivation and validation of gray-box models to estimate noninvasive in-vivo percentage glycated hemoglobin using digital volume pulse waveform

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shifat Hossain ◽  
Shantanu Sen Gupta ◽  
Tae-Ho Kwon ◽  
Ki-Doo Kim
Keyword(s):  
Blood Vessel ◽  
Glycated Hemoglobin ◽  
Blood Oxygenation ◽  
Physiological Basis ◽  
Pearson's R ◽  
Finger Model ◽  
Volume Pulse ◽  
Digital Volume Pulse ◽  
Pearson’S R

AbstractGlycated hemoglobin and blood oxygenation are the two most important factors for monitoring a patient’s average blood glucose and blood oxygen levels. Digital volume pulse acquisition is a convenient method, even for a person with no previous training or experience, can be utilized to estimate the two abovementioned physiological parameters. The physiological basis assumptions are utilized to develop two-finger models for estimating the percent glycated hemoglobin and blood oxygenation levels. The first model consists of a blood-vessel-only hypothesis, whereas the second model is based on a whole-finger model system. The two gray-box systems were validated on diabetic and nondiabetic patients. The mean absolute errors for the percent glycated hemoglobin (%HbA1c) and percent oxygen saturation (%SpO2) were 0.375 and 1.676 for the blood-vessel model and 0.271 and 1.395 for the whole-finger model, respectively. The repeatability analysis indicated that these models resulted in a mean percent coefficient of variation (%CV) of 2.08% and 1.74% for %HbA1c and 0.54% and 0.49% for %SpO2 in the respective models. Herein, both models exhibited similar performances (HbA1c estimation Pearson’s R values were 0.92 and 0.96, respectively), despite the model assumptions differing greatly. The bias values in the Bland–Altman analysis for both models were – 0.03 ± 0.458 and – 0.063 ± 0.326 for HbA1c estimation, and 0.178 ± 2.002 and – 0.246 ± 1.69 for SpO2 estimation, respectively. Both models have a very high potential for use in real-world scenarios. The whole-finger model with a lower standard deviation in bias and higher Pearson’s R value performs better in terms of higher precision and accuracy than the blood-vessel model.

scholarly journals Derivation and Validation of Gray-Box Models to Estimate Non-Invasive In-vivo Percentage Glycated Hemoglobin Using Digital Volume Pulse Waveform

2020 ◽  
Author(s):  
Shifat Hossain ◽  
Shantanu Sen Gupta ◽  
Tae-Ho Kwon ◽  
Ki-Doo Kim
Keyword(s):  
Blood Vessel ◽  
Glycated Hemoglobin ◽  
Blood Oxygenation ◽  
Diabetic Patients ◽  
Physiological Basis ◽  
Glucose Levels ◽  
Finger Model ◽  
Volume Pulse ◽  
Digital Volume Pulse

Abstract Glycated hemoglobin and blood oxygenation are the two most important factors for monitoring a patient’s oxygen levels in the blood and the amount of average blood glucose levels. Digital Volume Pulse acquisition is a convenient method, even for a person with no previous training or experience, can be utilized to estimate the two abovementioned physiological parameters. The physiological basis assumptions are utilized to develop two-finger models for estimating the percent glycated hemoglobin and blood oxygenation levels. The first model consists of a blood vessel only hypothesis, while the second model is based on a whole-finger model system. We validated our two gray-box systems on diabetic and non-diabetic patients and obtained the mean absolute errors for the percent glycated hemoglobin (%HbA1c) and percent oxygen saturation (%SpO2) of 0.375 and 1.676, respectively, for the blood vessel model and 0.271 and 1.395, respectively, for the whole-finger model. The precision analysis indicated that these models resulted in 2.08% and 1.74% mean %CV for %HbA1c and 0.54% and 0.49% mean %CV for %SpO2 in the respective models. Herein, both models exhibit close performances to each other (HbA1c estimation Pearson R values are 0.92 and 0.96, respectively), even though the model assumptions greatly differed between them. Both of the models have a very high potential to be used in real-world scenarios. The whole-finger model performs better in terms of higher precision and accuracy compared to the blood vessel model.

scholarly journals Quantitative Analysis of Different Multi-Wavelength PPG Devices and Methods for Noninvasive In-Vivo Estimation of Glycated Hemoglobin

2021 ◽  
Vol 11 (15) ◽  
pp. 6867
Author(s):  
Shifat Hossain ◽  
Chowdhury Azimul Haque ◽  
Ki-Doo Kim
Keyword(s):  
Glycated Hemoglobin ◽  
Estimation Error ◽  
Realistic Model ◽  
Blood Oxygenation ◽  
Accurate Estimation ◽  
Model Parameters ◽  
Diabetes Diagnosis ◽  
Sensor Noise ◽  
Glucose Levels

Diabetes is a serious disease affecting the insulin cycle in the human body. Thus, monitoring blood glucose levels and the diagnosis of diabetes in the early stages is very important. Noninvasive in vivo diabetes-diagnosis procedures are very new and require thorough studies to be error-resistant and user-friendly. In this study, we compare two noninvasive procedures (two-wavelength- and three-wavelength-based methods) to estimate glycated hemoglobin (HbA1c) levels in different scenarios and evaluate them with error level calculations. The three-wavelength method, which has more model parameters, results in a more accurate estimation of HbA1c even when the blood oxygenation (SpO2) values change. The HbA1c-estimation error range of the two-wavelength model, due to change in SpO2, is found to be from −1.306% to 0.047%. On the other hand, the HbA1c estimation error for the three-wavelength model is found to be in the magnitude of 10−14% and independent of SpO2. The approximation of SpO2 from the two-wavelength model produces a lower error for the molar concentration based technique (−4% to −1.9% at 70% to 100% of reference SpO2) as compared to the molar absorption coefficient based technique. Additionally, the two-wavelength model is less susceptible to sensor noise levels (max SD of %error, 0.142%), as compared to the three-wavelength model (max SD of %error, 0.317%). Despite having a higher susceptibility to sensor noise, the three-wavelength model can estimate HbA1c values more accurately; this is because it takes the major components of blood into account and thus becomes a more realistic model.

scholarly journals Noninvasive In Vivo Estimation of Blood-Glucose Concentration by Monte Carlo Simulation

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4918
Author(s):  
Chowdhury Azimul Haque ◽  
Shifat Hossain ◽  
Tae-Ho Kwon ◽  
Ki-Doo Kim
Keyword(s):  
Monte Carlo ◽  
Blood Glucose ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Synthetic Data ◽  
Real Data ◽  
Pearson's R ◽  
Blood Glucose Concentrations ◽  
Finger Model

Continuous monitoring of blood-glucose concentrations is essential for both diabetic and nondiabetic patients to plan a healthy lifestyle. Noninvasive in vivo blood-glucose measurements help reduce the pain of piercing human fingertips to collect blood. To facilitate noninvasive measurements, this work proposes a Monte Carlo photon simulation-based model to estimate blood-glucose concentration via photoplethysmography (PPG) on the fingertip. A heterogeneous finger model was exposed to light at 660 nm and 940 nm in the reflectance mode of PPG via Monte Carlo photon propagation. The bio-optical properties of the finger model were also deduced to design the photon simulation model for the finger layers. The intensities of the detected photons after simulation with the model were used to estimate the blood-glucose concentrations using a supervised machine-learning model, XGBoost. The XGBoost model was trained with synthetic data obtained from the Monte Carlo simulations and tested with both synthetic and real data (n = 35). For testing with synthetic data, the Pearson correlation coefficient (Pearson’s r) of the model was found to be 0.91, and the coefficient of determination (R2) was found to be 0.83. On the other hand, for tests with real data, the Pearson’s r of the model was 0.85, and R2 was 0.68. Error grid analysis and Bland–Altman analysis were also performed to confirm the accuracy. The results presented herein provide the necessary steps for noninvasive in vivo blood-glucose concentration estimation.

CODEM Instrument

GeroPsych ◽  
2014 ◽  
Vol 27 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Anne Kuemmel (This author contributed eq ◽  
Julia Haberstroh (This author contributed ◽  
Johannes Pantel
Keyword(s):  
Convergent Validity ◽  
Interrater Reliability ◽  
Discriminant Validity ◽  
Assessment Tool ◽  
Intraclass Correlation ◽  
Well Being ◽  
Communication Behavior ◽  
People With Dementia ◽  
Pearson's R ◽  
Pearson’S R

Communication and communication behaviors in situational contexts are essential conditions for well-being and quality of life in people with dementia. Measuring methods, however, are limited. The CODEM instrument, a standardized observational communication behavior assessment tool, was developed and evaluated on the basis of the current state of research in dementia care and social-communicative behavior. Initially, interrater reliability was examined by means of videoratings (N = 10 people with dementia). Thereupon, six caregivers in six German nursing homes observed 69 residents suffering from dementia and used CODEM to rate their communication behavior. The interrater reliability of CODEM was excellent (mean κ = .79; intraclass correlation = .91). Statistical analysis indicated that CODEM had excellent internal consistency (Cronbach’s α = .95). CODEM also showed excellent convergent validity (Pearson’s R = .88) as well as discriminant validity (Pearson’s R = .63). Confirmatory factor analysis verified the two-factor solution of verbal/content aspects and nonverbal/relationship aspects. With regard to the severity of the disease, the content and relational aspects of communication exhibited different trends. CODEM proved to be a reliable, valid, and sensitive assessment tool for examining communication behavior in the field of dementia. CODEM also provides researchers a feasible examination tool for measuring effects of psychosocial intervention studies that strive to improve communication behavior and well-being in dementia.

What Has Direct Cortical and Subcortical Electrostimulation Taught Us about Neurolinguistics?

2019 ◽  
pp. 185-211
Author(s):  
Hugues Duffau
Keyword(s):  
White Matter ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Great Accuracy ◽  
Subcortical White Matter ◽  
Cerebral Lesions ◽  
Physiological Basis ◽  
Postoperative Mri ◽  
The Brain

Investigating the neural and physiological basis of language is one of the most important challenges in neurosciences. Direct electrical stimulation (DES), usually performed in awake patients during surgery for cerebral lesions, is a reliable tool for detecting both cortical and subcortical (white matter and deep grey nuclei) regions crucial for cognitive functions, especially language. DES transiently interacts locally with a small cortical or axonal site, but also nonlocally, as the focal perturbation will disrupt the entire subnetwork sustaining a given function. Thus, in contrast to functional neuroimaging, DES represents a unique opportunity to identify with great accuracy and reproducibility, in vivo in humans, the structures that are actually indispensable to the function, by inducing a transient virtual lesion based on the inhibition of a subcircuit lasting a few seconds. Currently, this is the sole technique that is able to directly investigate the functional role of white matter tracts in humans. Thus, combining transient disturbances elicited by DES with the anatomical data provided by pre- and postoperative MRI enables to achieve reliable anatomo-functional correlations, supporting a network organization of the brain, and leading to the reappraisal of models of language representation. Finally, combining serial peri-operative functional neuroimaging and online intraoperative DES allows the study of mechanisms underlying neuroplasticity. This chapter critically reviews the basic principles of DES, its advantages and limitations, and what DES can reveal about the neural foundations of language, that is, the large-scale distribution of language areas in the brain, their connectivity, and their ability to reorganize.

scholarly journals Pre-Planned and Non-Planned Agility in Patients Ongoing Rehabilitation after Knee Surgery: Design, Reliability and Validity of the Newly Developed Testing Protocols

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 146
Author(s):  
Ivan Peric ◽  
Miodrag Spasic ◽  
Dario Novak ◽  
Sergej Ostojic ◽  
Damir Sekulic
Keyword(s):  
Total Knee Arthroplasty ◽  
Body Mass ◽  
Knee Arthroplasty ◽  
Arthroscopic Surgery ◽  
The Body ◽  
Clinical Population ◽  
Pearson's R ◽  
Total Knee ◽  
Type Of Surgery ◽  
Pearson’S R

Background: Due to its association with the risk of falling and consequent injury, the importance of agility is widely recognized, but no study so far has examined the different facets of agility in an untrained/clinical population. The aim of this study was to evaluate the reliability, validity, and correlates of newly developed tests of non-planned agility (NPA) and pre-planned agility (PPA) in an untrained/clinical sample. Methods: The sample comprised 38 participants older than 40 years (22 females, age: 56.1 ± 17.3 years, height: 170.4 ± 10.8 cm, mass: 82.54 ± 14.79 kg) who were involved in a rehabilitation program following total knee arthroplasty and knee arthroscopy. Variables included age, gender, type of surgery, history of fall, anthropometrics/body composition, and newly developed tests of NPA and PPA. Results: The results showed the high inter-testing- (ICC > 0.95, CV < 9%), and intra-testing-reliability (ICC > 0.96, CV < 9) of the newly developed tests. PPA and NPA were found to be valid in differentiation between age groups (>50 yrs. vs. <50 yrs.), and genders, with better performance in younger participants and males. Only NPA differentiated participants according to type of surgery, with better performance in those who had arthroscopic surgery, than those who had total knee arthroplasty. No differences in NPA and PPA were established between groups based on fall-history. In females, the body mass (Pearson’s r = 0.58 and 0.59, p < 0.001) and body fatness (Pearson’s r = 0.64 and 0.66, p < 0.001) were negatively correlated, while the lean body mass (Pearson’s r = 0.70 and 0.68, p < 0.001) was positively correlated with PPA and NPA. The NPA and PPA were highly correlated (Pearson’s r = 0.98, p < 0.001). Conclusions: We found that the proposed tests are reliable when evaluating agility characteristics in an untrained/clinical population after knee arthroplasty/arthroscopy. Further evaluation of the specific validity of the proposed tests in other specific subsamples is warranted.

scholarly journals Phosphorylation of pericyte FAK-Y861 affects tumour cell apoptosis and tumour blood vessel regression

Angiogenesis ◽  
2021 ◽  
Author(s):  
Delphine M. Lees ◽  
Louise E. Reynolds ◽  
Ana Rita Pedrosa ◽  
Marina Roy-Luzarraga ◽  
Kairbaan M. Hodivala-Dilke
Keyword(s):  
Blood Vessel ◽  
Tumour Growth ◽  
Vascular Endothelial Cell ◽  
Vessel Density ◽  
In Vivo Studies ◽  
Blood Vessel Density ◽  
Tumour Vessel ◽  
Vessel Regression ◽  
Tumour Blood

AbstractFocal adhesion kinase (FAK) is a non-receptor tyrosine kinase that is overexpressed in many cancer types and in vivo studies have shown that vascular endothelial cell FAK expression and FAK-phosphorylation at tyrosine (Y) 397, and subsequently FAK-Y861, are important in tumour angiogenesis. Pericytes also play a vital role in regulating tumour blood vessel stabilisation, but the specific involvement of pericyte FAK-Y397 and FAK-Y861 phosphorylation in tumour blood vessels is unknown. Using PdgfrβCre + ;FAKWT/WT, PdgfrβCre + ;FAKY397F/Y397F and PdgfrβCre + ;FAKY861F/Y861F mice, our data demonstrate that tumour growth, tumour blood vessel density, blood vessel perfusion and pericyte coverage were affected only in late stage tumours in PdgfrβCre + ;FAKY861F/Y861F but not PdgfrβCre + ;FAKY397F/Y397F mice. Further examination indicates a dual role for pericyte FAK-Y861 phosphorylation in the regulation of tumour vessel regression and also in the control of pericyte derived signals that influence apoptosis in cancer cells. Overall this study identifies the role of pericyte FAK-Y861 in the regulation of tumour vessel regression and tumour growth control and that non-phosphorylatable FAK-Y861F in pericytes reduces tumour growth and blood vessel density.

scholarly journals Supervised Machine Learning Methods and Hyperspectral Imaging Techniques Jointly Applied for Brain Cancer Classification

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3827
Author(s):  
Gemma Urbanos ◽  
Alberto Martín ◽  
Guillermo Vázquez ◽  
Marta Villanueva ◽  
Manuel Villa ◽  
...  
Keyword(s):  
Machine Learning ◽  
Blood Vessel ◽  
Hyperspectral Imaging ◽  
Imaging Techniques ◽  
Venous Blood ◽  
Healthy Tissue ◽  
Supervised Machine Learning ◽  
Support Vector ◽  
Arterial Blood

Hyperspectral imaging techniques (HSI) do not require contact with patients and are non-ionizing as well as non-invasive. As a consequence, they have been extensively applied in the medical field. HSI is being combined with machine learning (ML) processes to obtain models to assist in diagnosis. In particular, the combination of these techniques has proven to be a reliable aid in the differentiation of healthy and tumor tissue during brain tumor surgery. ML algorithms such as support vector machine (SVM), random forest (RF) and convolutional neural networks (CNN) are used to make predictions and provide in-vivo visualizations that may assist neurosurgeons in being more precise, hence reducing damages to healthy tissue. In this work, thirteen in-vivo hyperspectral images from twelve different patients with high-grade gliomas (grade III and IV) have been selected to train SVM, RF and CNN classifiers. Five different classes have been defined during the experiments: healthy tissue, tumor, venous blood vessel, arterial blood vessel and dura mater. Overall accuracy (OACC) results vary from 60% to 95% depending on the training conditions. Finally, as far as the contribution of each band to the OACC is concerned, the results obtained in this work are 3.81 times greater than those reported in the literature.

scholarly journals An in vivo model allowing continuous observation of human vascular formation in the same animal over time

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yohei Tsukada ◽  
Fumitaka Muramatsu ◽  
Yumiko Hayashi ◽  
Chiaki Inagaki ◽  
Hang Su ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
Human Blood ◽  
Molecular Mechanisms ◽  
Human Tumor ◽  
Continuous Observation ◽  
In Vivo Models ◽  
Cranial Window ◽  
Pathological Conditions

AbstractAngiogenesis contributes to numerous pathological conditions. Understanding the molecular mechanisms of angiogenesis will offer new therapeutic opportunities. Several experimental in vivo models that better represent the pathological conditions have been generated for this purpose in mice, but it is difficult to translate results from mouse to human blood vessels. To understand human vascular biology and translate findings into human research, we need human blood vessel models to replicate human vascular physiology. Here, we show that human tumor tissue transplantation into a cranial window enables engraftment of human blood vessels in mice. An in vivo imaging technique using two-photon microscopy allows continuous observation of human blood vessels until at least 49 days after tumor transplantation. These human blood vessels make connections with mouse blood vessels as shown by the finding that lectin injected into the mouse tail vein reaches the human blood vessels. Finally, this model revealed that formation and/or maintenance of human blood vessels depends on VEGFR2 signaling. This approach represents a useful tool to study molecular mechanisms of human blood vessel formation and to test effects of drugs that target human blood vessels in vivo to show proof of concept in a preclinical model.

Active induction of bubble liposome at the bifurcation of in vivo blood vessel with optical measurement and robotic positioning

2016 ◽  
Author(s):  
Kohji Masuda ◽  
Shinya Miyazawa ◽  
Hikaru Wada ◽  
Tomohiro Kurokawa ◽  
Kaoru Natsume ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Optical Measurement
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