Non-Invasive Biosensor for Measurement of Blood Urea Level in Human Subjects Using Reverse Iontophoresis

2015 ◽  
Keyword(s):  
Human Subjects ◽  
Reverse Iontophoresis ◽  
Urea Level ◽  
Non Invasive ◽  
Blood Urea Level

Reverse iontophoresis: a non-invasive technique for measuring blood urea level

2003 ◽  
Vol 18 (10) ◽  
pp. 1032-1037 ◽  
Author(s):  
Ismail Tuncer Degim ◽  
Sibel Ilbasmis ◽  
Rusen Dundaroz ◽  
Yusuf Oguz
Keyword(s):  
Invasive Technique ◽  
Reverse Iontophoresis ◽  
Urea Level ◽  
Non Invasive ◽  
Blood Urea Level

scholarly journals Reconstruction of input functions from a dynamic PET image with sequential administration of 15O2 and H215O for noninvasive and ultra-rapid measurement of CBF, OEF, and CMRO2

2017 ◽  
Vol 38 (5) ◽  
pp. 780-792 ◽  
Author(s):  
Nobuyuki Kudomi ◽  
Yukito Maeda ◽  
Hiroyuki Yamamoto ◽  
Yuka Yamamoto ◽  
Tetsuhiro Hatakeyama ◽  
...  
Keyword(s):  
Rate Constants ◽  
Human Subjects ◽  
Invasive Procedure ◽  
Invasive Technique ◽  
Invasive Approach ◽  
Non Invasive ◽  
Sequential Administration ◽  
Invasive Method ◽  
The Difference ◽  
Arterial Input Functions

CBF, OEF, and CMRO2 images can be quantitatively assessed using PET. Their image calculation requires arterial input functions, which require invasive procedure. The aim of the present study was to develop a non-invasive approach with image-derived input functions (IDIFs) using an image from an ultra-rapid O2 and C15O2 protocol. Our technique consists of using a formula to express the input using tissue curve with rate constants. For multiple tissue curves, the rate constants were estimated so as to minimize the differences of the inputs using the multiple tissue curves. The estimated rates were used to express the inputs and the mean of the estimated inputs was used as an IDIF. The method was tested in human subjects ( n = 24). The estimated IDIFs were well-reproduced against the measured ones. The difference in the calculated CBF, OEF, and CMRO2 values by the two methods was small (<10%) against the invasive method, and the values showed tight correlations ( r = 0.97). The simulation showed errors associated with the assumed parameters were less than ∼10%. Our results demonstrate that IDIFs can be reconstructed from tissue curves, suggesting the possibility of using a non-invasive technique to assess CBF, OEF, and CMRO2.

scholarly journals Novel glucose-responsive of the transparent nanofiber hydrogel patches as a wearable biosensor via electrospinning

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gun Jin Kim ◽  
Kyu Oh Kim
Keyword(s):  
Continuous Monitoring ◽  
Interstitial Fluid ◽  
High Sensitivity ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
High Permeability ◽  
Reverse Iontophoresis ◽  
Glucose Levels ◽  
Non Invasive ◽  
High Enzyme

Abstract Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions. However, the high crystallinity of NFs limits the achievement of transparency via electrospinning. Transparent poly(vinyl alcohol)/β-cyclodextrin polymer NF hydrogels contacted with reverse iontophoresis electrodes were prepared for the development of a non-invasive continuous monitoring biosensor platform of interstitial fluid glucose levels reaching ~ 1 mM. We designed the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogels, which exhibit flexibility, biocompatibility, excellent absorptivity (DI water: 21.9 ± 1.9, PBS: 41.91 ± 3.4), good mechanical properties (dried: 12.1 MPa, wetted: 5.33 MPa), and high enzyme activity of 76.3%. Owing to the unique features of PVA/β-CD/GOx containing AuNPs NF hydrogels, such as high permeability to bio-substrates and rapid electron transfer, our biosensors demonstrate excellent sensing performance with a wide linear range, high sensitivity(47.2 μA mM−1), low sensing limit (0.01 mM), and rapid response time (< 15 s). The results indicate that the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogel patch sensor can measure the glucose concentration in human serum and holds massive potential for future clinical applications.

Tactile Eye Pressure Measurement Through the Eyelid

2015 ◽  
Author(s):  
Eniko T. Enikov ◽  
Péter P. Polyvás ◽  
Gholam Peyman ◽  
Sean Mccafferty
Keyword(s):  
Intraocular Pressure ◽  
Human Subjects ◽  
Statistical Error ◽  
Applanation Tonometry ◽  
Tactile Sensors ◽  
Non Invasive ◽  
Digital Palpation ◽  
Early Results ◽  
Novel Method ◽  
Eye Pressure

This article presents the early results from a 10-person human subject study evaluating the accuracy of a novel method of indirect estimation of intraocular pressure using tactile sensors. Manual digital palpation tonometery is an old method used to estimate the eye pressure through palpation with ones fingers. Based on this concept, we present an instrumented measurement method, where multiple tactile stiffness sensors are used to infer the intraocular pressure of the eye. The method is validated using experimental data gathered from human subjects with eye pressures from 15 to 22 mmHg and determined by Goldman applanation tonometry (GAT). Bland-Altman plots comparing the GAT measurements and the proposed through-the-eye-lid tonometry indicate a statistical error of 5.16 mmHg, within the 95% confidence interval, which compares favorably with the FDA-mandated error bound of 5 mmHg. Details on the unit operation and data filtering are also presented. Due to its indirect and non-invasive nature, the proposed new tactile tonometry method can be applied at home as a self-administered home tonometer for management of glaucoma.

Azostix test for blood urea level

1968 ◽  
Vol 41 (491) ◽  
pp. 878-878
Author(s):  
W. H. Dempster
Keyword(s):  
Urea Level ◽  
Blood Urea Level

Non-invasive monitoring of phenytoin by reverse iontophoresis

2004 ◽  
Vol 22 (5) ◽  
pp. 427-433 ◽  
Author(s):  
Benoı̂t Leboulanger ◽  
Richard H Guy ◽  
M.Begoña Delgado-Charro
Keyword(s):  
Invasive Monitoring ◽  
Reverse Iontophoresis ◽  
Non Invasive

A stepwise procedure for evaluating irritant materials in normal volunteer subjects

1995 ◽  
Vol 14 (2) ◽  
pp. 204-211 ◽  
Author(s):  
P.J. Dykes ◽  
D.R. Black ◽  
M. York ◽  
A.D. Dickens ◽  
R. Marks
Keyword(s):  
Sodium Hydroxide ◽  
Human Subjects ◽  
Normal Volunteer ◽  
Capillary Blood ◽  
Laser Doppler ◽  
Non Invasive ◽  
Accuracy And Precision ◽  
Forearm Skin ◽  
Cutaneous Response ◽  
Stepwise Procedure

1 The cutaneous response to a known irritant has been assessed in human volunteer subjects using both clini cal scoring and two non-invasive instrumental meth ods ; erythema measurement using an erythema meter and capillary blood flow using a laser Doppler device. 2 Aqueous solutions (0.5% and 1%) of sodium hydroxide were applied to back skin for 3, 15 and 60 min with assessments immediately after removal and at 1, 24 and 48 hours. 3 Increased erythema was seen with increasing duration of exposure and an increase was also seen at 1 h, 24 h and 48 h after removal of the patch. The results obtained with the erythema meter paralleled the clini cal erythema scores. However, the laser Doppler device showed the greatest changes immediately after removal of the patch with subsequent readings show ing a gradual decrease. 4 Statistical analysis of the data has been carried out to determine the accuracy and precision of the assess ment procedures and to determine the minimum test panel size for detecting irritant reactions. 5 Comparison between back and forearm skin indicated a greater sensitivity to sodium hydroxide on the back. 6 The results of this study define an ethical approach to testing irritant materials in human subjects and pro vide the basis for the development of a classification system for cutaneous irritants.

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