Radial artery pulse wave velocity: a new characterization technique and the instabilities associated with the respiratory phase and breath-holding.

Objective. Pulse wave velocity (PWV) is a key diagnostic parameter of the cardiovascular system's state. However, approaches aimed at PWV characterization often suffer from inevitable drawbacks. Statistical results demonstrating how closely PWV in the radial artery (RA) and the respiration phase correlate, as well as RA PWV evolution during breath-holding (BH), have not yet been presented in the literature. The aims of this study are (a) to propose a simple robust technique for measuring RA PWV, (b) to reveal the phase relation between the RA PWV and spontaneous breathing, and (c) to disclose the influence of BH on the RA PWV.Approach.The high-resolution remote breathing monitoring method Sorption-Enhanced Infrared Thermography (SEIRT) and the new technique aimed at measuring RA PWV described in this paper were used synchronously, and their measurement data were processed simultaneously.Main results. Spontaneous breathing leaves a synchronous 'trace' on the RA PWV. The close linear correlation of the respiration phase and the phase of concomitant RA PWV changes is statistically confirmed in five tested people (Pearson's r is of the order of 0.5-0.8, P < 0.05). The BH appreciably affects the RA PWV. A phenomenon showing that the RA PWV is not indifferent to hypoxia is observed for the first time.Significance.The proposed technique for RA PWV characterization has high prospects in biomedical diagnostics. The presented pilot study deserves attention in the context of the mutual interplay between respiratory and cardiovascular systems. It may also be useful in cases where peripheral pulse wave propagation helps assess respiratory function.

Infrared Thermography as a Powerful, Versatile, and Elegant Research Tool in Chemistry: Principles and Application to Catalysis and Adsorption.

In this Review, diverse chemical problems that have been approached by means of infrared thermography (IRT) are covered in depth. Moreover, some novel steps forward in this field are made, described and discussed. Namely, the latest-generation IRT performance capabilities are harnessed in full; the initial phase of catalytic CO oxidation (called "fast ignition") is presented at the 0.01 s temporal resolution; at the same resolution, the thermal manifestation of the adsorption-desorption wave propagation after the gaseous reactant pulsed (0.6 s) wetting is exhibited. Furthermore, a radical difference in the thermal behavior of differently calcined γ-Al2 O3 supported Au catalysts, which underwent successive H2 O and CO attacks, is demonstrated, and the generally accepted fact that the catalyst temperature reflects the catalytic activity is validated experimentally. It is shown that latest-generation IRT may serve as unique and highly informative research tool in chemistry.

A Novel High-Resolution Method for the Respiration Rate and Breathing Waveforms Remote Monitoring.

A search for robust noninvasive methods permitting to discern the respiration subtle peculiarities in mammals is a topical issue. A novel approach called "sorption-enhanced infrared thermography" (SEIRT), helping to solve this problem, is described. Its benefits spring from the integration of the infrared thermography (IRT) and chemical physics (phase transition heat release/absorption) within a single method. The SEIRT opportunities were verified in the investigation of 42 humans, 49 rats and 4 minipigs whose breathing waveforms were revealed to the last detail. It is shown that the SEIRT-obtained breathing-conditioned temperature response may exceed 10 °C (!) even in small animals (rats) and that the SEIRT sensitivity is 4.5-250 times higher than that of the matched IRT-based techniques. The new method is validated by a comparison with that based on thorax breathing movement (TBM). It is shown that the SEIRT-determined breaths have a close correlation with those determined via TBM (r = + 1.000, p ≪ 0.05); this is also true for breathing intervals (r = + 0.9772, p ≪ 0.05). SEIRT opens up the way to a high-resolution noncontact quantitative evaluation of respiration rate and breathing waveforms in both humans and animals. It may become a cutting-edge technique in diagnostic medicine and biomedical research.

Thermographic imaging in sports and exercise medicine: A Delphi study and consensus statement on the measurement of human skin temperature.

The importance of using infrared thermography (IRT) to assess skin temperature (tsk) is increasing in clinical settings. Recently, its use has been increasing in sports and exercise medicine; however, no consensus guideline exists to address the methods for collecting data in such situations. The aim of this study was to develop a checklist for the collection of tsk using IRT in sports and exercise medicine. We carried out a Delphi study to set a checklist based on consensus agreement from leading experts in the field. Panelists (n = 24) representing the areas of sport science (n = 8; 33%), physiology (n = 7; 29%), physiotherapy (n = 3; 13%) and medicine (n = 6; 25%), from 13 different countries completed the Delphi process. An initial list of 16 points was proposed which was rated and commented on by panelists in three rounds of anonymous surveys following a standard Delphi procedure. The panel reached consensus on 15 items which encompassed the participants' demographic information, camera/room or environment setup and recording/analysis of tsk using IRT. The results of the Delphi produced the checklist entitled "Thermographic Imaging in Sports and Exercise Medicine (TISEM)" which is a proposal to standardize the collection and analysis of tsk data using IRT. It is intended that the TISEM can also be applied to evaluate bias in thermographic studies and to guide practitioners in the use of this technique.

Lasers and infrared thermography: advantageous cooperation.

In a brief review, the beneficial outcomes that have arisen from simultaneous use of laser- and infrared thermography (IRT)-based techniques are demonstrated. The most recent literary and original experimental results collected from different research and practical areas are presented. It is shown that modern IRT acts as an indispensable laser partner in various biomedical and many other applications and technologies. And vice versa, the laser-based methods and techniques often serve as an appropriate research instrument enriching IRT measurement data with independently obtained information.

Systemic vascular response to brachial arteries crossclamping may prognosticate the outcome of remote ischemic preconditioning.

Remote ischemic preconditioning (RIPC) is a recent trend in cardiovascular medicine. From the literature, it may be deduced that physiological changes resulted from repeated episodes of brachial-cuff inflation/deflation during RIPC provoke, in some way, systemic "training" of the whole organism. At the same time, the effectiveness of such a "training" is substantially different in different humans, and the latter remains unclear. We propose the hypothesis as follows: the magnitude of real-time response of cardiovascular system to transient upper limb ischemia serves as a predictive indicator of the organismal sensitivity to RIPC preventive procedure and RIPC clinical efficiency in a particular person. The hypothesized prognosis of the RIPC-induced different resistance to post-ischemic reperfusion injury in different patients is represented in a quantitative manner using dynamic infrared examination of all human limbs simultaneously. With this screening method, it is clearly shown that different cohorts of healthy individuals exhibit different organismal responsiveness to upper limb arterial transient crossclamping. If proven, our hypothesis could have important implications for emergency medicine.

FPA-based infrared thermography as applied to the study of cutaneous perspiration and stimulated vascular response in humans.

This review gives an overview of focal plane array (FPA)-based infrared (IR) thermography as a powerful research method in the field of physiology and medicine. Comparison of the gained results with the data previously obtained by other authors with other research tools is given. Outer thermoregulatory manifestations displayed by the human organism subjected to whole-body heating (sauna bath) and physical loads (exercise bicycling) are quantitatively analysed. Some details of human body emotional sweating (psycho-physiological effect) are reported. Particular attention is paid to studying active sweat glands as individual objects. All experimental data were obtained with the help of a high-sensitivity (0.03 degrees C) fast 128 x 128 InAs IR detector-based thermal imaging system operating in the short-wave spectral region (2.5 to 3 microm) and perfectly suiting medical purposes. It is shown that IR thermography makes it possible to overcome limitations inherent to contact measuring means that were traditionally used before in thermal studies. It is also shown that heterogeneous thermograms displayed by organisms with disturbed inner equilibrium can be quantitatively analysed in terms of statistical parameters of related surface-temperature histograms, such as the mean temperature and the standard deviation of temperature (SDT). The increase and the decrease in SDT turned out to be typical of prolonged physical load and subsequent relaxation, and of external whole-body heating, respectively. Explanation of this result based on a hypothesis advanced within the context of the doctrine of human-organism evolution is given. Skin-temperature distribution function accompanying the relaxed organism in normality was found to closely resemble normal-distribution function. Symmetry break down and variation of the shape of this characteristic may serve as an indicator of homeostasis shift and can be used as a quantitative criterion for the latter. A new phenomenon, stable punctate hidrosis, is discovered and described. The term sweatology is introduced to refer to the discussed specific research area in biomedical science.