Hemoglobin Concentration In Human Blood Research Articles

Magneto-optical Goos–Hänchen shift in uniaxial anisotropic epsilon-near-zero metamaterials

Abstract We theoretically investigate the enhancement of the magneto-optical Goos-Hänchen (MOGH) shift in multilayer structure combining uniaxially anisotropic epsilon-near-zero (ENZ) metamaterials with magneto-optical (MO) materials. The structure enables the excitation of magneto-optical surface plasmon resonance (MOSPR) without the need for a prism or grating coupler, thereby achieving a significant enhancement of the MOGH shift. The effect of the thickness of the ENZ layer and the type of magnetic metal in this structure on the MOGH shift is also discussed. Based on the above structure, we design a high-sensitivity miniature biosensor that is used for the detection of hemoglobin concentration in human blood. The maximum sensitivity achievable with this sensor is 1.4×106 λ/RIU. The results of this investigation contribute to the development of biosensors towards miniaturization and integration.

Graphene-Based Chiral Metasurface for Generation of Tunable Circular Dichroism—Design and Sensor Applications

In this article, we have proposed a graphene-based 2-D chiral metasurface for the mid-infrared region. The chirality factor in terms of circular dichroism (CD) can be modulated by tuning the chemical potential of graphene. We have demonstrated our metasurface design in a reflection mode of operation. The structure consists of arc-shaped etched graphene patterns on a SiO2 substrate. CD of 0.85 with a chemical potential of 0.95 eV has been obtained for normal incidence. The CD value can be reduced to 0.30 just by tuning the chemical potential to 0.55 eV. We then exploited this CD factor for various sensing applications. We have shown that by tuning the CD, we can design a biosensor for the detection of hemoglobin concentration in human blood. A sensitivity of 2091.33 nm/RIU has been obtained for the detection of anemic conditions from the normal concentration of hemoglobin. We have also demonstrated that the same sensor design can be used for the detection of hazardous solvents such as chlorobenzene and trifluoroacetic acid (TFA). Finally, we have proposed a gas-sensing application considering hazardous gases like carbon dioxide and ethylene oxide for demonstration purposes. A maximum sensitivity of 6600 and 1250 nm/RIU has been reported for carbon dioxide and ethylene oxide.

Optimization of surface plasmon resonance-based biosensors for monitoring hemoglobin levels in human blood

Biological sensors based on surface plasmon resonance (SPR) are used in a wide range of fields such as pharmacy, medicine, food and drink safety to measure biological and chemical parameters. These sensors function by detecting changes in the refractive index of the sample environment. In this paper a biosensor design based on surface Plasmon resonance is introduced for the purpose of monitoring hemoglobin concentrations in human blood. Our design is based on a Kretschmann structure which contains an SF10 prism, with metal, graphene and metal dichalcogenide layers. The optical source considered here is a He–Ne laser with the wavelength of 632.8 nm. The effect of adding graphene and metal dichalcogenide layers to the structure of these sensors has been investigated. Our investigation of this structure shows that depending on the specific structure of metal dichalcogenide, the addition of this layer increases the sensitivity of the sensor. Using this optimized structure, our main goal of a blood health monitoring device can be achieved. We use this structure to determine the reflection coefficients that correspond with the healthy range of hemoglobin concentration in human blood based on the refractive index of human blood. This sensor is first optimized for sensitivity using water as a sample, this optimized sensor is then used to investigate the range of human blood in a healthy state of blood iron for men and women between the ages of 20 until 80 years. Results show that the reflection coefficients of the optimized structure for healthy range of hemoglobin concentrations for an adult man is from 0.6805(a.u) to 0.7067(a.u) and for an adult female is from 0.6547(a.u) to 0.6583(a.u).

New Plasmonic Biosensors for Determination of Human Hemoglobin Concentration in Blood

Two new types of plasmonic biosensors are applied for detection of hemoglobin concentration in human blood by using the angular interrogation method. The first type of the fiber with five layers is made by a SiO2 core surrounded by GaP, gold, Al2O3 and hemoglobin layers. The second type of the fiber with six layers is made by a ZBLAN core surrounded by NaF, silicon, silver, Al2O3 and hemoglobin layers. For some thicknesses of the interior layers and for a hemoglobin concentration close to the mean value of a male human at a laser wavelength (1.53 μm), a large figure of merit and maximum value of the amplitude sensitivity are obtained at an angle very close to the resonance angle. For the second type of the sensor, 0.0036 g/dl resolution is obtained, which is 10% finer than the estimated detection limit (0.004 g/dl) reported very recently by using an electrochemical method. Also, our resolution is better than the previously reported value (0.006 g/dl if the angular resolution is 0.001°) by using a gold–aluminum-based surface plasmon resonance sensor.

Invasive and non-invasive point-of-care testing and point-of-care monitoring of the hemoglobin concentration in human blood - how accurate are the data?

In this review, scientific investigations of point-of-care testing (POCT) and point-of-care monitoring (POCM) devices are summarized with regard to the measurement accuracy of the hemoglobin concentration. As a common basis, information according to the Bland and Altman principle [bias, limits of agreement (LOA)] as well as the measurement accuracy and precision are considered, so that the comparability can be mapped. These collected data are subdivided according to the manufacturers, devices and procedures (invasive and non-invasive). A total of 31 devices were identified. A comparability of the scientific investigations in particular was given for 23 devices (18 invasive and five non-invasive measuring devices). In terms of measurement accuracy, there is a clear leap between invasive and non-invasive procedures, while no discernible improvement can be derived in the considered time frame from 2010 to 2018. According to the intended use, strict specifications result from the clinical standards, which are insufficiently met by the systems. More stringent requirements can be derived both in the area of blood donation and in the treatment of patients.

Gold–aluminum-based surface plasmon resonance sensor with a high quality factor and figure of merit for the detection of hemoglobin

A gold (Au) and aluminum (Al)-based surface plasmon resonance (SPR) sensor, with a high-quality factor and figure of merit, for the detection of hemoglobin concentration in human blood is proposed. The sensing performance of a bimetallic Au grating over an Al film-based sensor depends on the thickness of the Al film. The sensor's performance is closely analyzed in terms of well-defined performance parameters: sensitivity, FWHM, and depth of SPR dips in order to optimize the thickness of Al film. With optimized thickness, we could achieve quality factor and figure of merit values of 286.2 RIU-1 and 0.97 deg-1, respectively. Al is chemically unstable, and, to address the oxidation problem, we analyzed the sensor with an ultrathin protective Au layer between the Au grating and Al film. We show that the introduction of an ultrathin Au layer gives stability to the sensor without much affecting the performance of the sensor. The obtained values of quality factor and figure of merit of the proposed sensor are 245.2 RIU-1 and 0.86 deg-1, respectively. We also discuss the potential of hemoglobin detection of the proposed sensor in the near-infrared region. Reported sensitivity of the sensor is 0.62°/dgL-1.

Graphene based chalcogenide fiber-optic evanescent wave sensor for detection of hemoglobin in human blood

Abstract Fiber optic evanescent wave sensor with graphene as an absorption-enhancing layer to measure hemoglobin concentration in human blood is proposed. Previous modal functions and experimental results describing the variation of optical constants of human blood with different hemoglobin concentrations in the near-infrared spectral region are considered for sensor design simulation. The sensor’s performance is closely analyzed in terms of its absorption coefficient, sensitivity, and detection limit. It is found that the proposed sensor should be operated at longer light wavelength to get more enhanced sensitivity and smaller detection limit. At 1000 nm wavelength, a detection limit of 18 μg/dL and sensitivity of 6.71 × 10−4 per g/dL is achievable with the proposed sensor. The sensitivity is found to be better for larger hemoglobin concentrations. The results are correlated with the evanescent wave penetration depth.

Simulation of Some Plasmonic Biosensors for Detection of Hemoglobin Concentration in Human Blood

Three recently published plasmonic biosensors based on a birefringent solid-core or a partial-solid-core microstructured optical fiber are simulated for detection of hemoglobin concentration in human blood. For a larger value of the number of holes n h but for the same value of the gold radius, the resonance spectral width and the difference between maximal amplitude sensitivity and resonant wavelengths are decreased, when the refractive index of the analyte is n a = 1.357. Also, the loss and maximum of the amplitude sensitivity are increased in the same conditions. At the resonant wavelength λ = 0.6496 μm for the devices with n h = 14, 17, and 35 holes and n a = 1.357, the hemoglobin concentration is close to the mean value (157.5 g/l) of a man.

Estimation of human-hemoglobin using honeycomb structure: An application of photonic crystal

This paper proposes a method to estimate the hemoglobin concentration in human blood using 2D honeycomb photonic crystal structure. Though a few works deal with similar kind of investigation, present research delivers an accurate estimation of hemoglobin as compared to previous works. The principle of investigation is based on linear variation of both photonic band gap and absorbance's with respect to different concentration of hemoglobin in human blood. Aside these variations, energy transmitted through honeycomb photonic crystal structure is also varied linearly with respect to same concentration. In this work, photonic band gap of honeycomb structure is found using plane wave expansion method, whereas absorbance of same structure is computed by employing Maxwell Curl equation. Finally, simulation result revealed that transmitted energy through two dimensional honeycomb photonic crystal structure containing blood is nicely fitted with linear trend line (R2=1) which lead to an accurate investigation of hemoglobin in human blood. At last, this paper proposes an experimental set up to measure the said concentrations with the help of an Arduino development board (Uno) containing Atmega 320 microcontroller.

Plasmonic biosensor for detection of hemoglobin concentration in human blood: Design considerations

Surface plasmon resonance (SPR) sensor for the detection of hemoglobin concentration in human blood is proposed. Previous experimental results describing variation of refractive index of human blood with hemoglobin concentration at different wavelengths are considered for theoretical calculations. The angular interrogation method along with silica substrate and gold layer is considered. The sensor's performance is closely analyzed in terms of well-defined performance parameters: sensitivity, accuracy, resolution, and signal-to-noise ratio, in order to achieve reliable and accurate hemoglobin detection. The influence of operating wavelength on the performance of sensor scheme is critically investigated. Performance comparison for two different substrates is carried out. The results are explained in terms of light coupling and plasmon resonance condition. The proposed biosensor has the potential to provide high sensitivity, accuracy, and large operating range of hemoglobin detection, along with much higher resolution compared with existing methods, thereby opening an easy and reliable window for biomedical applications.

Effects of abnormal hemoglobin concentration in human blood on membrane diffusing capacity of the lung and on pulmonary capillary blood volume.

In 13 patients with chronic anemia or polycythemia but normal lung function, and in 7 healthy students a statistically significant correlation between hemoglobin concentration and membrane diffusing capacity of the lung for CO was found. A membrane diffusing constant resulting from extrapolation for hemoglobin concentration 0 g/ was 13.4% of the predicted value (100% for Hb = 14.5 g%). A change of 1 g hemoglobin/100 ml changes membrane diffusing capacity for 6.3% of the predicted value. This result confirms the theory of Koyama and Mochizuki that the diffusing capacity of the pulmonary membrane is a function of the hemoglobin concentration of pulmonary capillary blood. In 3 healthy subjects with normal hemoglobin concentration the effect of DL/VA inhomogenities in the lung on single-breath diffusing capacity and its subdivisions was examined. An increase of DLCO for 20% of predicted normal at decreasing apnea time (tA = 5 sec) resulted from an increased pulmonary capillary blood volume for 50--90% of the predicted value (at tA = 10 sec), whereas membrane diffusing capacity remained unchanged over the range of apnea times. The reasons for this finding are still unknown; alteration of pulmonary perfusion at changing apnea time is taken into account.