Comparison between the standard method and the 30° curved tongue depressor-aided technique for insertion of a laryngeal mask airway: a randomized controlled trial.

BACKGROUND: Laryngeal mask airway (LMA) has been increasingly used for airway management; however, LMA insertion can be difficult and cause adverse effects. Therefore, the rapid, safe, and effective insertion of LMA is necessary. This study aimed to compare the efficacy of the standard method with that of the 30° curved tongue depressor-aided technique for LMA insertion to determine the superior technique. METHODS: This study included 154 patients aged 18-70 years (American Society of Anesthesiologists class I or II) scheduled for general anesthesia. The patients were randomly assigned to the standard LMA insertion group (Group C, n = 77) or the 30° curved tongue depressor-aided LMA insertion group (Group T, n = 77). The primary outcome evaluated was the first-attempt success rate. The secondary outcomes were the second-attempt success rate, insertion time, fiberoptic position grade, oropharyngeal leak pressure (OPLP), and adverse events. RESULTS: The first-attempt success rate was significantly higher in Group T than in Group C (97.40% vs. 88.31%, P = 0.029). The second-attempt success rate (P = 0.209), insertion time (P = 0.340), fiberoptic position grade (P = 0.872), and OPLP (P = 0.203) were slightly improved in Group T; however, there was no statistical significance. Bleeding events were reduced in Group T than in Group C (6.49% vs. 14.29%); however, there was no statistical significance. The incidence of sore throat symptoms was significantly reduced in Group T than in Group C (5.19% vs. 15.58%, P = 0.035). CONCLUSIONS: The curved tongue depressor-aided technique significantly improved the first-attempt success rate of LMA insertion and reduced the incidence of sore throat symptoms. TRIAL REGISTRATION: KCT0004964; Registered at https://cris.nih.go.kr on April 27, 2020.

Evaluation of the Whiteout During Fiberoptic Endoscopic Evaluation of Swallowing and Examination of Its Correlation with Pharyngeal Residue and Aspiration.

To evaluate the whiteout duration (WOd) and intensity (WOi) during Fiberoptic Endoscopic Evaluation of Swallowing (FEES) and examine their correlation with each other and age, gender, bolus consistencies, residue, and aspiration. Retrospective review of 75 videorecorded FEES. The first swallow of each of the following were scored: "Empty" swallow, semisolids, solids, and liquids (International dysphagia diet standardization initiative (IDDSI) 4, 7, 0, respectively). Data scored for each swallow included WOd, WOi, Penetration and aspiration scale (PAS), Pharyngeal residue (Yale Pharyngeal Residue Severity Rating Scale, YPR-SRS), and saliva pooling (Murray Secretion scale, MSS). The highest PAS and YPR-SRS for each consistency during the entire examination were also collected. WOd was significantly longer for stronger WOi in IDDSI4 swallows (p = 0.019). WOi was weaker for IDDSI0 swallows compared to IDDSI7, IDDSI4, and empty swallows (p < 0.05). Patients with saliva pooling had significantly shorter WOd (0.81 ± 0.3 s for MSS = 0 vs. 0.62 ± 0.24 for MSS = 3, p = 0.04). Lower WOi was associated with higher mean age for IDDSI0 (mean ages of 73 ± 12, 64 ± 14, 73 ± 7, 59 ± 16 years for intensity levels 1-4 respectively, p = 0.019). Swallows with weaker WOi and longer WOd had significantly more aspirations in IDDSI7 (28.8% of PAS ≥ 6 for intensity 2 vs 0% for intensity 4, p = 0.003 and 0.77 ± 0.4 s for PAS 1-2 vs. 1.02 ± 0.08 for PAS 6-8, p = 0.049). WOi and WOd are significantly associated with each other. WOi may vary for different bolus consistencies and decreases with age. Longer WOd and weaker WOi are associated with penetration-aspiration. Shorter WOd is associated with saliva pooling.

Dynamic Measurement of a Cancer Biomarker: Towards In Situ Application of a Fiber-Optic Ball Resonator Biosensor in CD44 Protein Detection.

The accuracy and efficacy of medical treatment would be greatly improved by the continuous and real-time monitoring of protein biomarkers. Identification of cancer biomarkers in patients with solid malignant tumors is receiving increasing attention. Existing techniques for detecting cancer proteins, such as the enzyme-linked immunosorbent assay, require a lot of work, are not multiplexed, and only allow for single-time point observations. In order to get one step closer to clinical usage, a dynamic platform for biosensing the cancer biomarker CD44 using a single-mode optical fiber-based ball resonator biosensor was designed, constructed and evaluated in this work. The main novelty of the work is an in-depth study of the capability of an in-house fabricated optical fiber biosensor for in situ detection of a cancer biomarker (CD44 protein) by conducting several types of experiments. The main results of the work are as follows: (1) Calibration of the fabricated fiber-optic ball resonator sensors in both static and dynamic conditions showed similar sensitivity to the refractive index change demonstrating its usefulness as a biosensing platform for dynamic measurements; (2) The fabricated sensors were shown to be insensitive to pressure changes further confirming their utility as an in situ sensor; (3) The sensor's packaging and placement were optimized to create a better environment for the fabricated ball resonator's performance in blood-mimicking environment; (4) Incubating increasing protein concentrations with antibody-functionalized sensor resulted in nearly instantaneous signal change indicating a femtomolar detection limit in a dynamic range from 7.1 aM to 16.7 nM; (5) The consistency of the obtained signal change was confirmed by repeatability studies; (6) Specificity experiments conducted under dynamic conditions demonstrated that the biosensors are highly selective to the targeted protein; (7) Surface morphology studies by AFM measurements further confirm the biosensor's exceptional sensitivity by revealing a considerable shift in height but no change in surface roughness after detection. The biosensor's ability to analyze clinically relevant proteins in real time with high sensitivity offers an advancement in the detection and monitoring of malignant tumors, hence improving patient diagnosis and health status surveillance.

Balloon-Shaped SMF Blood Glucose Concentration and Temperature Sensor Based on Core-Offset Structure.

A blood glucose concentration and temperature sensor with a balloon-shaped single-mode fiber (SMF) based on a core-offset structure is proposed and experimentally demonstrated. The balloon-shaped SMF is created by offset-fusing a straight-line SMF between two other SMFs, thereby forming a Mach-Zehnder interferometer (MZI). The core-offset structure can effectively excite higher-order cladding modes. The experimental results showed that the maximum sensitivity of blood glucose concentration was 0.331 nm/(mmol/l) and the maximum sensitivity of temperature was 0.216 nm/°C when the offset distance was 10 µm. Dual-parameter measurement was achieved through a dual-parameter matrix. In addition, the sensor has characteristics such as simple structure, low cost, good stability, and electromagnetic interference resistance, making it potentially valuable for diagnosing high blood glucose and related conditions.

Photonic molecule state transition by collision.

We investigate the impact of collisions with two-frequency photonic molecules aiming to observe internal dynamic behavior and challenge their strong robustness. Versatile interaction scenarios show intriguing state changes expressed through modifications of the resulting state such as temporal compression and unknown collision-induced spectral tunneling. These processes show potential for efficient coherent supercontinuum generation and all-optical manipulation.

Low-Cost Online Monitoring System for the Etching Process in Fiber Optic Sensors by Computer Vision.

The present research exposes a novel methodology to manufacture fiber optic sensors following the etching process by Hydrofluoric Acid deposition through a real-time monitoring diameter measurement by computer vision. This is based on virtual instrumentation developed with the National Instruments® technology and a conventional digital microscope. Here, the system has been tested proving its feasibility by the SMS structure diameter reduction from its original diameter of 125 µ until approximately 42.5 µm. The results obtained have allowed us to demonstrate a stable state behavior of the developed system during the etching process through diameter measurement at three different structure sections. Therefore, this proposal will contribute to the etched fiber optic sensor development that requires reaching an enhanced sensitivity. Finally, to demonstrate the previously mentioned SMS without chemical corrosion, and the etched manufactured SMS, both have been applied as glucose concentration sensors.

Design and Implementation of a Passive Autoranging Circuit for Hybrid FBG-PZT Photonic Current Transducer.

In this paper, we present a novel technique for passively autoranging a photonic current transducer (PCT) that incorporates a current transformer (CT), piezoelectric transducer (PZT) and fiber Bragg grating (FBG). Due to the usage of single-mode fiber and FBG, multiple PCTs can be interconnected and distributed over a long distance, for example along a power network, greatly reducing the cost of sensor deployment and offering other unique advantages. The autoranging technique relies on the usage of multiple, serially connected CT burden resistors and associated static MOSFET switches to realize instantaneous shortening of the resistors in response to increasing measured current. This functionality is realized passively, utilizing a modular, µW-power comparator circuit that powers itself from the electrical energy supplied by the CT within a small fraction of the 50/60 Hz cycle. The resultant instantaneous changes in sensor gain will be ultimately detected by the central FBG interrogator through real-time analysis of the optical signals and will be used to apply appropriate gain scaling for each sensor. The technique will facilitate the usage of a single PCT to cover an extended dynamic range of the measurement that is required to realize a combined metering- and protection-class current sensor. This paper is limited to the description of the design process, construction, and testing of a prototype passive autoranging circuitry for integration with the PCT. The two-stage circuitry that is based on two burden resistors, 1 Ω and 10 Ω, is used to prove the concept and demonstrate the practically achievable circuit characteristics. It is shown that the circuit correctly reacts to input current threshold breaches of approximately 2 A and 20 A within a 3 ms reaction time. The circuit produces distinct voltage dips across burden resistors that will be used for signal scaling by the FBG interrogator.

Research Advances on Fiber-Optic SPR Sensors with Temperature Self-Compensation.

The fiber-optic surface plasmon resonance sensor has very promising applications in environmental monitoring, biochemical sensing, and medical diagnosis, due to the superiority of high sensitivity and novel label-free microstructure. However, the influence of ambient temperature is inevitable in practical sensing applications, and even the higher the sensitivity, the greater the influence. Therefore, how to eliminate temperature interference in the sensing process has become one of the hot issues of this research field in recent years, and some accomplishments have been achieved. This paper mainly reviews the research results on temperature self-compensating fiber-optic surface plasmon sensors. Firstly, it introduces the mechanism of a temperature self-compensating fiber-optic surface plasmon resonance sensor. Then, the latest development of temperature self-compensated sensor is reviewed from the perspective of various fiber-optic sensing structures. Finally, this paper discusses the most recent applications and development prospects of temperature self-compensated fiber-optic surface plasmon resonance sensors.

Effect of resin composite shade on digital fiber-optic transillumination imaging in vitro.

Digital imaging fiber-optic transillumination (DIFOTI) devices have been used to detect caries, a technique without using X-rays. However, the effects of resin composites (RCs) shades on the images acquired with DIFOTI devices have not been investigated. Thus, this study aimed to elucidate the influence of RC shade on the images obtained with DIFOTI technique. Three shades (A1, A3, and Opaque) for each of four flowable RCs were filled on a cavity prepared in a left mandibular first premolar obtained from a donated body. Then, transmission images with a DIFOTI device (DIAGNOcam; KaVo, Biberach, Germany) were acquired, and the average lightness values of the images in the RC and enamel were used to calculate differences between those areas. To clarify the influence of the optical translucency and color on DIFOTI images, the color parameters (L*, a* and b*) of each RC were obtained with black and white backgrounds. The color differences between the backgrounds were calculated as transparency parameter (TP) values. The number of repetitions was set to 10. Differences in the lightness value of the shades varied in each RC. The difference in lightness was significantly associated with the TP value and color parameters of L* (p < 0.01), with negative (R = - 0.81) and positive (R = 0.84) correlations, respectively. In conclusion, DIFOTI images of RCs with high optical translucency resembled those of the natural tooth structure.

High-density multi-fiber photometry for studying large-scale brain circuit dynamics.

Animal behavior originates from neuronal activity distributed across brain-wide networks. However, techniques available to assess large-scale neural dynamics in behaving animals remain limited. Here we present compact, chronically implantable, high-density arrays of optical fibers that enable multi-fiber photometry and optogenetic perturbations across many regions in the mammalian brain. In mice engaged in a texture discrimination task, we achieved simultaneous photometric calcium recordings from networks of 12-48 brain regions, including striatal, thalamic, hippocampal and cortical areas. Furthermore, we optically perturbed subsets of regions in VGAT-ChR2 mice by targeting specific fiber channels with a spatial light modulator. Perturbation of ventral thalamic nuclei caused distributed network modulation and behavioral deficits. Finally, we demonstrate multi-fiber photometry in freely moving animals, including simultaneous recordings from two mice during social interaction. High-density multi-fiber arrays are versatile tools for the investigation of large-scale brain dynamics during behavior.

Two-photon endomicroscopy with microsphere-spliced double-cladding antiresonant fiber for resolution enhancement.

We demonstrate a miniature fiber-optic two two-photon endomicroscopy with microsphere-spliced double-cladding antiresonant fiber for resolution enhancement. An easy-to-operate process for fixing microsphere permanently in an antiresonant fiber core, by arc discharge, is proposed. The flexible fiber-optic probe is integrated with a parameter of 5.8 mm × 49.1 mm (outer diameter × rigid length); the field of view is 210 µm, the resolution is 1.3 µm, and the frame rate is 0.7 fps. The imaging ability is verified using ex-vivo mouse kidney, heart, stomach, tail tendon, and in-vivo brain neural imaging.

Temperature and external strain sensing with metal-embedded optical fiber sensors for structural health monitoring.

An optical fiber with both temperature and strain fiber Bragg grating sensors were embedded into an aluminum cast structure during the casting process. Temperature and strain calibrations were carried out respectively for the metal-embedded sensors. Temperature and external strain decoupling was further demonstrated in a temperature range from 25 to 80 °C and an external strain range from 0 to ∼110 µÉ›. With the interpolated temperature measured by two temperature sensors at different positions, the external strain could be decoupled from temperature and thermal strain at the strain sensor. The temperature and external strain values obtained from our embedded optical fiber sensors agreed well with reference values, revealing the good performance of the metal-embedded optical fiber sensors. The difference between the measured values and the reference values are within ±5 µÉ› for external strain and ±1 °C for temperature. With only a single fiber, the in-situ temperature and external strain information in the aluminum structure can be monitored in real time, representing an important step towards fiber-optic smart casts. Our investigation demonstrates that embedded optical fiber sensors can be a promising method for structural health monitoring of metallic structures.

Rapid identification of human muscle disease with fibre optic Raman spectroscopy.

The diagnosis of muscle disorders ("myopathies") can be challenging and new biomarkers of disease are required to enhance clinical practice and research. Despite advances in areas such as imaging and genomic medicine, muscle biopsy remains an important but time-consuming investigation. Raman spectroscopy is a vibrational spectroscopy application that could provide a rapid analysis of muscle tissue, as it requires no sample preparation and is simple to perform. Here, we investigated the feasibility of using a miniaturised, portable fibre optic Raman system for the rapid identification of muscle disease. Samples were assessed from 27 patients with a final clinico-pathological diagnosis of a myopathy and 17 patients in whom investigations and clinical follow-up excluded myopathy. Multivariate classification techniques achieved accuracies ranging between 71-77%. To explore the potential of Raman spectroscopy to identify different myopathies, patients were subdivided into mitochondrial and non-mitochondrial myopathy groups. Classification accuracies were between 74-89%. Observed spectral changes were related to changes in protein structure. These data indicate fibre optic Raman spectroscopy is a promising technique for the rapid identification of muscle disease that could provide real time diagnostic information. The application of fibre optic Raman technology raises the prospect of in vivo bedside testing for muscle diseases which would significantly streamline the diagnostic pathway of these disorders.

In situ ground settlement sensor for oil-tank monitoring by combining a fiber-optic low-coherent interferometry with a fine mechanical design.

An in situ robust ground settlement (IR-GS) sensor was designed to meet the requirements for oil-tank health monitoring by combining a low-coherent fiber-optic interferometry with a fine mechanical spline shaft. A floating mirror was mounted on the shaft and moved up and down along with the liquid surface. The liquid-contained chambers were hydraulically connected at the bottom by using a liquid-filled tube. The liquid level inside each chamber was initially at equal level. One of the chambers was fixed on a steady ground point, which was chosen in a surveying point of view and served as a reference. The others were distributed around an oil tank and separated the tank's perimeter into eight equal spans. Thereby, the health states of the oil tank were able to be evaluated based on these sensing results. Interrogation of the sensor was employed via a low-coherent fiber-optic Michelson interferometer. One path of the interferometer was composed by the floating mirror, whereupon a light was reflected. The other path was projected to a mirror that was fixed on a stepping motor. Therefore, the corresponding liquid level could be optically surveyed. Differential settlements between each chamber and the reference served as a measure of how much the liquid level was changed from its initials. Experimental tests demonstrated that this IR-GS design, with the optimized shape and weights of the spline shaft, could overcome the error caused by dust, hysteresis, temperature, etc. and meet the practical requirement in the accuracy of ±0.5mm. A practical application was carried out, and its long-term stability has been proved.

Single-mode fiber curvature sensor based on SPR.

A fiber surface plasmon resonance (SPR) sensor is widely used in high-sensitivity refractive index measurement, but there is less research on curvature measurement. In this paper, a single-mode fiber curvature sensor based on SPR is designed and fabricated. By employing bending, the transmitted light in the fiber core leaks into the cladding. A 50 nm gold film is coated outside the cladding, and the evanescent field of the cladding after bending contacts the gold film to cause SPR. When the curvature changes, the coupled cladding mode and intensity are different; that is, the SPR incident angle and evanescent field intensity are different, so as to realize the dual parameters of SPR resonance wavelength and depth of the resonance valley changing with curvature. By experiments, the influence of different cutoff wavelengths of single-mode fiber on the performance of the sensor is studied. The testing results indicate that with the decrease in cutoff wavelength of the single-mode fiber, the valley depth sensitivity of the sensor increases, and the half height width (FWHM) decreases. When the cutoff wavelength of the single-mode fiber is 630 nm, the valley depth sensitivity of the sensor is 0.0088a.u/m-1, the wavelength sensitivity is 0.26nm/m-1, and the average FWHM is only 21 nm. The proposed single-mode fiber curvature sensor based on SPR has a narrow FWHM and an opening threshold. It can also realize no opening threshold by introducing a coreless fiber, which provides a new solution, to the best of our knowledge, for the diversified detection of fiber SPR sensors.

Fabrication and diameter analysis of a single-ended SMF tip structure.

Optical fiber technology combined with surface plasmon resonance enables rapid, precise detection of chemical, biochemical, and biological parameters. Many hybrid optical fiber structures have been suggested in recent decades to increase the sensitivity of optical fiber biosensors. In this work, an optical fiber tip structure is fabricated on single-mode fiber (SMF) by etching in a hydrofluoric acid (40%) solution at room temperature. The proposed method of tip formation utilizing wet etching is efficient for fabricating the highly sensitive fiber structures that are required for the development of optical fiber-based biosensors. The diameter measurement of fabricated fiber tip formation is done using a compound microscope.

A comparative analysis of diagnostic values of high-frequency ultrasound and fiberoptic ductoscopy for pathologic nipple discharge.

BACKGROUND: This study aimed to compare the diagnostic accuracy of high-frequency ultrasound (HFUS) and fiberoptic ductoscopy (FDS) for pathologic nipple discharge (PND). METHODS: HFUS and FDS were conducted in 210 patients with PND (248 lesions) treated at our hospital. The diagnostic accuracy of these two methods was compared using pathological diagnosis as the standard. RESULTS: Among 248 lesions, 16 and 15 of 16 malignant lesions were accurately diagnosed by HFUS and FDS, respectively. Of 232 benign lesions, 183 and 196 cases were accurately diagnosed by HFUS and FDS, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of HFUS in diagnosis of intraductal lesions were 84.36% (95% CI 79.26-88.39%), 60% (95% CI 23.07-92.89%), 96.03% (95% CI 96.55-99.83%), and 7.31% (95% CI 2.52-19.4%) respectively. The sensitivity, specificity, PPV, and NPV of FDS in diagnosis of intraductal lesions were 86.83% (95% CI 82.00-90.52%), 100% (95% CI 56.55-100%), 100% (95% CI 98.21-100%), and 13.51% (95% CI 5.91-27.98%) respectively. Diagnostic accuracy rates of HFUS and FDS were 83.87% (208/248) and 85.08% (211/248), respectively, exhibiting no statistically differences (χ2 = 0.80, P > 0.05). The accuracy of HFUS combined with FDS was 93.14% (231/248), showing statistically differences (χ2 = 10.91, P < 0.05). CONCLUSIONS: Both HFUS and FDS demonstrated high diagnostic values for PND. HFUS has the advantage of non-invasive for nipple discharge with duct ectasia, exhibited good qualitative and localization diagnostic values. It is the preferred evaluation method for patients with nipple discharge. When HFUS cannot identify the cause of PND, FDS can be considered.

On-site rapid and simultaneous detection of acetamiprid and fipronil using a dual-fluorescence lab-on-fiber biosensor.

A dual-fluorescence lab-on-fiber biosensor was developed for the rapid and simultaneous on-site determination of acetamiprid and fipronil, based on time-resolved effect and indirect competitive immunoassay principle. The optical fiber modified with two hapten-protein conjugates serves as a bifunctional bio-probe. The dual-color fluorescent reporters were prepared via labeling acetamiprid and fipronil antibodies with Cy5.5 and Alexa Fluor 555, which were excited at 635-nm and 520-nm laser wavelengths, respectively. In the presence of targets, the binding sites of corresponding antibodies were occupied and less antibodies were connected to the probe surface, resulting in the reduction of fluorescence signal. The concentration of acetamiprid and fipronil was determined by measuring the fluorescence signals at 568 nm and 702 nm (emission wavelengths), respectively. Under optimal conditions, the linear response range was 14.2-225.4 ng/L for acetamiprid and 25.1-162.8 ng/L for fipronil, and the limit of detection was 6.51 ng/L and 17.8 ng/L for acetamiprid and fipronil, respectively. The method was successfully applied to the simultaneous detection of acetamiprid and fipronil in three environmental samples, and the recoveries were between 90 and 128%. The dual-fluorescence lab-on-fiber biosensor provides a feasible platform for simultaneous and rapid detection of multiple pesticide residues. A dual-fluorescence lab-on-fiber biosensor was developed for the rapid and simultaneous on-site determination of acetamiprid and fipronil. A bifunctional bio-probe was prepared from the optical fiber modified with two hapten-protein conjugates. Acetamiprid and fipronil antibodies were labeled with different fluorophores and used as dual-color fluorescent reporters.

Toward a Structural Health Monitoring Methodology for Concrete Structures under Dynamic Loads Using Embedded FBG Sensors and Strain Mapping Techniques.

A data-driven-based methodology for SHM in reinforced concrete structures using embedded fiber optic sensors and pattern recognition techniques is presented. A prototype of a reinforced concrete structure was built and instrumented in a novel fashion with FBGs bonded directly to the reinforcing steel bars, which, in turn, were embedded into the concrete structure. The structure was dynamically loaded using a shaker. Superficial positive damages were induced using bonded thin steel plates. Data for pristine and damaged states were acquired. Classifiers based on Mahalanobis' distance of the covariance data matrix were developed for both supervised and unsupervised pattern recognition with an accuracy of up to 98%. It was demonstrated that the proposed sensing scheme in conjunction with the developed supervised and unsupervised pattern recognition techniques allows the detection of slight stiffness changes promoted by damages, even when strains are very small and the changes of these associated with the damage occurrence may seem negligible.

Extension of Duplexed Single-Ended Distributed Temperature Sensing Calibration Algorithms and Their Application in Geothermal Systems.

Fiber-optic distributed temperature sensing (DTS) has been widely used since the end of the 20th century, with various industrial, Earth sciences, and research applications. To obtain precise thermal measurements, it is important to extend the currently available DTS calibration methods, considering that environmental and deployment factors can strongly impact these measurements. In this work, a laboratory experiment was performed to assess a currently available duplexed single-ended DTS calibration algorithm and to extend it in case no temperature information is available at the end of the cables, which is extremely important in geothermal applications. The extended calibration algorithms were tested in different boreholes located in the Atacama Desert and in the Central Andes Mountains to estimate the geothermal gradient in these regions. The best algorithm found achieved a root mean square error of 0.31 ± 0.07 °C at the far end of a ~1.1-km cable, which is much smaller than that obtained using the manufacturer algorithm (2.17 ± 0.35 °C). Moreover, temperature differences between single- and double-ended measurements were less than 0.3 °C at the far end of the cable, which results in differences of ~0.5 °C km-1 when determining the geothermal gradient. This improvement in the geothermal gradient is relevant, as it can reduce the drilling depth by at least 700 m in the study area. Future work should investigate new extensions of the algorithms for other DTS configurations and determining the flow rate of the Central Andes Mountains artesian well using the geothermal profile provided by the DTS measurements and the available data of the borehole.