A Review of Process near Infrared Spectroscopy: 1980–1994

1993 ◽  
Vol 1 (4) ◽  
pp. 221-245 ◽  
Author(s):  
Jerry Workman
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Literature Search ◽  
Near Infrared ◽  
Process Analysis ◽  
The State ◽  
Chronological Order ◽  
Measurement Scheme ◽  
The Subject

For this review, papers on NIR process analysis were categorised according to their overall configuration and measurement scheme. This analyser taxonomy was chosen to demonstrate the state of the current use of process analyser terms and to allow the reader to access a broad range of applications by referring to the specific measuring characteristics of the analyser. The basis for this review was a literature search covering the period from January 1980 to January 1994 on the subject of Process NIR and FT-NIR analysis. Each section is in chronological order to allow the reader to observe the development (and refinement) of process NIR from 1980 to the present.

Noninvasive measurement of forearm blood flow and oxygen consumption by near-infrared spectroscopy

1994 ◽  
Vol 76 (3) ◽  
pp. 1388-1393 ◽  
Author(s):  
R. A. De Blasi ◽  
M. Ferrari ◽  
A. Natali ◽  
G. Conti ◽  
A. Mega ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Healthy Subjects ◽  
Near Infrared ◽  
Forearm Blood Flow ◽  
Vascular Occlusion ◽  
Venous Occlusion ◽  
The Subject

We applied near-infrared spectroscopy (NIRS) for the simultaneous measurement of forearm blood flow (FBF) and oxygen consumption (VO2) in the human by inducing a 50-mmHg venous occlusion. Eleven healthy subjects were studied both at rest and after hand exercise during vascular occlusion. FBF was also measured by strain-gauge plethysmography. FBF measured by NIRS was 1.9 +/- 0.8 ml.100 ml-1.min-1 at rest and 8.2 +/- 2.9 ml.100 ml-1.min-1 after hand exercise. These values showed a correlation (r = 0.94) with those obtained by the plethysmography. VO2 values were 4.6 +/- 1.3 microM O2 x 100 ml-1.min-1 at rest and 24.9 +/- 11.2 microM O2 x 100 ml-1.min-1 after hand exercise. The scatter of the FBF and VO2 values showed a good correlation between the two variables (r = 0.93). The results demonstrate that NIRS provides the particular advantage of obtaining the contemporary evaluation of blood flow and VO2, allowing correlation of these two variables by a single maneuver without discomfort for the subject.

scholarly journals Perfusion Changes at the Forehead Measured by Photoplethysmography during a Head-Down Tilt Protocol

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 71
Author(s):  
Tomas Ysehak Abay ◽  
Kamran Shafqat ◽  
Panayiotis A. Kyriacou
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Venous Blood ◽  
Arterial Oxygen ◽  
Large Variability ◽  
Large Vein ◽  
The Subject ◽  
Induced Changes

Photoplethysmography (PPG) signals from the forehead can be used in pulse oximetry as they are less affected by vasoconstriction compared to fingers. However, the increase in venous blood caused by the positioning of the patient can deteriorate the signals and cause erroneous estimations of the arterial oxygen saturation. To date, there is no method to measure this venous presence under the PPG sensor. This study investigates the feasibility of using PPG signals from the forehead in an effort to estimate relative changes in haemoglobin concentrations that could reveal these posture-induced changes. Two identical reflectance PPG sensors were placed on two different positions on the forehead (above the eyebrow and on top of a large vein) in 16 healthy volunteers during a head-down tilt protocol. Relative changes in oxygenated ( Δ HbO 2 ), reduced ( Δ HHb) and total ( Δ tHb) haemoglobin were estimated from the PPG signals and the trends were compared with reference Near Infrared Spectroscopy (NIRS) measurements. Also, the signals from the two PPG sensors were analysed in order to reveal any difference due to the positioning of the sensor. Δ HbO 2 , Δ HHb and Δ tHb estimated from the forehead PPGs trended well with the same parameters from the reference NIRS. However, placing the sensor over a large vasculature reduces trending against NIRS, introduces biases as well as increases the variability of the changes in Δ HHb. Forehead PPG signals can be used to measure perfusion changes to reveal venous pooling induced by the positioning of the subject. Placing the sensor above the eyebrow and away from large vasculature avoids biases and large variability in the measurements.

Human calf microvascular compliance measured by near-infrared spectroscopy

2000 ◽  
Vol 88 (2) ◽  
pp. 369-372 ◽  
Author(s):  
T. Binzoni ◽  
V. Quaresima ◽  
M. Ferrari ◽  
E. Hiltbrand ◽  
P. Cerretelli
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Region Of Interest ◽  
Venous System ◽  
Vasomotor Response ◽  
Head Up Tilt ◽  
Nirs Data ◽  
The Subject ◽  
Human Calf

The purpose of this study is to develop a new method for the measurement in humans of the compliance of the microvascular superficial venous system of the lower limb by near-infrared spectroscopy (NIRS). This method is complementary to strain-gauge plethysmography, which does not allow compliance between deep and superficial venous or between venous and arterial compartments to be distinguished. In practice, hydrostatic pressure (P) changes were induced in a calf region of interest by head-up tilt of the subject from α = −10 to 75°. For P ≤ 24 mmHg, the measured compliance [0.086 ± 0.005 (SD) ml ⋅ l− 1 ⋅ mmHg− 1] based on NIRS data of total, deoxygenated, and oxygenated hemoglobin, reflects essentially that of the superficial venous system. For P ≥ 24 mmHg, no distinction can be made between arterial and venous volumes changes. However, by following the changes in oxy- and deoxyhemoglobin in the P range −16 to 100 mmHg, it appears to be possible to assess the characteristics of the vasomotor response of the arteriolar system.

The state of water in soft contact lenses explored with near infrared spectroscopy and Aquaphotomics

NIR news ◽  
2017 ◽  
Vol 28 (6) ◽  
pp. 9-12
Author(s):  
Jelena Munćan
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Contact Lenses ◽  
Water Structure ◽  
The State ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
State Of Water ◽  
Three State Model

The structure of water in hydrogel materials of soft contact lenses was investigated by near infrared spectroscopy and Aquaphotomics. Near infrared spectroscopy offers rapid, reagent free, and nondestructive characterization of hydrogel materials, while Aquaphotomics provides detailed insight into the complex water structure inside the hydrogel consisting of many water molecular species. These findings push the limits of our knowledge beyond the current “three-state” model of water in hydrogels, while at the same time provide information about the state of the polymer itself thus justifying the “water molecular-mirror” concept of Aquaphotomics.

Near-Infrared Spectroscopy in Laboratory and Process Analysis

2012 ◽  
Author(s):  
Manel Alcalà ◽  
Marcelo Blanco ◽  
José C. Menezes ◽  
Pedro M. Felizardo ◽  
Ana Garrido ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Process Analysis
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