Ming-Yie Jan

Microcirculatory characteristics of acupuncture points obtained by laser Doppler flowmetry

Acupuncture points (acupoints) form part of the meridian system that constitutes the most fundamental concept in oriental medicine, but their physiological basis has not been clarified. In this study we employed laser Doppler flowmetry (LDF) to extract the microcirculatory characteristics of acupoints and their surrounding tissues, and we interpreted the results from the viewpoint of microcirculatory physiology. Three groups of measurements were performed focusing on the following two important acupoints in oriental medicine in healthy volunteers (n = 13 for group A and n = 9 for groups B and C, respectively): Hoh-Ku (Li4, on the hand) and Ching-Ku (B64, on the foot). The two groups of measurements around Hoh-Ku (Groups A and B) were so designed as to examine the effect of the direction of the nonacupoint away from the acupoint, whereas comparison between the Hoh-Ku and the Ching-Ku measurements was to verify whether the phenomenon was consistent in the upper and the lower extremities. We found that the mean LDF signals were significantly larger at the acupoints than in their surrounding tissues (all p < 0.05), which indicates a larger blood supply into the microvascular beds of acupoints. The results indicate that the physical properties of the vascular structure of acupoints may affect the perfusion resistance, and thereby modulate the microcirculatory perfusion in accordance with tissue needs. This finding facilitates the localization of acupoints, helps in identifying the connection between microcirculatory physiology and responses to acupoint stimulation, and introduces an objective research method for understanding the mechanisms that underlie oriental medicine.

Pressure pulse velocity is related to the longitudinal elastic properties of the artery

It is known that arteries in their natural position are always subject to a longitudinal stress. However, the effect of this strong longitudinal tension has seldom been addressed. In this paper, we point out that the traditional pulse wave velocity formulae considering only the circumferential elasticity fail to include all the important energies. We present a vigorous derivation of a pressure wave equation, the pressure wave equation with total energy, which considers all the important energies of the whole arterial system by treating the arterial wall and the blood as one system. Our model proposes that the energy transport in the main arterial system is primarily via the transverse vibration motion of the elastic wall. The final equation indicates that the longitudinal stress is essential and the high frequency phase velocity is related to the longitudinal tension along the arterial wall and its Youngs shearing modulus. By applying this equation, we suggest that longitudinal elastic property is an important factor in hemodynamics and in the treatment of cardiovascular diseases.

Analysis of transverse wave as a propagation mode for the pressure pulse in large arteries

A general axial momentum equation for fluid inside a transverse vibrating elastic tube is derived here. In a system with high pressure and low elastic modulus, transverse motion of the wall contributes important nonlinear forces, and the longitudinal fluid wave which assumes that flow is governed by the Navier-Stokes equation cannot describe the pulse wave completely. By comparing the transverse elastic wave with the longitudinal fluid wave, we conclude that transverse wave is a significant wave mode in large arteries. The longitudinal stress force, commonly ignored in the literature, can be considered as a significant factor that influences the propagation of the arterial pulse.

Connection between RR-interval length and the pulsatile microcirculatory flow

The present study used laser Doppler flowmetry (LDF) to investigate the connection between skin microcirculatory flow and the length of the RR interval (LRR). Local heating was performed on healthy volunteers to further elucidate its effect on LDF index. ECG and LDF signals were measured in 102 trials on seven volunteers. Each experiment involved a 5 min control and a 5 min heating-effect sequence. Each laser Doppler flux pulse was categorized into four groups according to its LRR compared with the 5 min average LRR. Synchronized averaging analysis was applied to the four groups of pulses to obtain their averaged waveforms, from which four flux parameters were calculated. The ac component of the flux increased significantly with increasing LRR, and the differences therein between the groups with LRR more than 4% smaller and more than 4% larger than the average LRR increased from 15.8% during the control period to 23.9% during the heating period. Understanding of the different flux responses between the control and local-heating experiments may aid the development of a new index, which helps to avoid LDFs main drawback of providing only qualitative measurement.

Noninvasive blood glucose monitoring using the optical signal of pulsatile microcirculation: a pilot study in subjects with diabetes

OBJECTIVE The objective of this study was to determine the conditions for optimizing measurements obtained with a noninvasive blood glucose monitor using the optical signal of pulsatile microcirculation (OSPM) in both prediabetic and diabetic subjects receiving medication. RESEARCH DESIGN AND METHODS Eighteen subjects (3 prediabetic, 15 diabetic) aged 61.8 [15.9] years (mean [S.D.]) were studied. OSPM was the pulsatile component (P) of the signal obtained and analyzed by a blood glucose monitor. The measurement was calibrated to the fingerstick meter for each subject for personal calibration. Data were obtained from all subjects using both meters. RESULTS A total of 179 data pairs were measured and analyzed. The validity of the position of the tested finger was assessed using the position criterion, which resulted in the removal of 38 data pairs. The criterion for the intensity of the P signal was satisfied by 141 data pairs, with nonconforming data (with a much lower P signal) mainly occurring below 26 degrees C. A total of 113 data points passed both criteria, and 100% of them fell within Zones A and B of the Clarke error grid. Data in Zones A and B exhibited a linear relationship (r=.81; slope=0.82; intercept=28.0) between noninvasive and fingerstick measurements. CONCLUSIONS Environmental temperature has the greatest influence on the capability of the OSPM technique to monitoring blood glucose concentration, which is subject dependent. The position of the tested finger is the second major factor, hence a carefully designed finger adaptor is essential.

The Physical Conditions of Different Organs Are Reflected Specifically in the Pressure Pulse Spectrum of the Peripheral Artery

We try to solve the “hemodynamic inverse problem” of the internal organs in terms of the peripheral pressure pulse spectrum analysis. Side-branch organs are approximated as resonators with own natural frequencies. They are depicted not as ordinary reflection sites but as antennas that receive energy from the main artery and undergo forced oscillations with selective frequencies. Every organ also reacts back to the main artery as a secondary “small heart source” that generated harmonic forces with maximum amplitude near its own natural frequency. The whole arterial system is in a steady distributed oscillatory state that is the superposition result of encountering the forces generated by the heart and many internal organs. A “frequency matching” theory of the organ and the main artery is proposed. The Fourier components of the pressure pulse in the arterial system are related to the matching conditions of different organs. In vivo studies in kidney and spleen of rats are provided.

Relations Between Beat-to-Beat Microcirculatory Blood Flow and Variations Therein

OBJECTIVE Analyzing the beat-to-beat cardiovascular variability (e.g., heart-rate variability analysis) provides important information regarding circulatory autonomic control. The present study aimed to use laser Doppler flowmetry (LDF) and beat-to-beat analysis to elucidate changes in the microcirculatory blood flow (MBF) and variations (MBFV) therein induced by local heating stimulation. METHOD For each experiment, we applied nonpainful local heating and recorded a 20-min heating effect, which was segmented into four measurements separated by 5 min as M1-M4. DCflux (average LDF flux) was calculated for each pulse, and the coefficient of variance of DCflux (DCCV) was then calculated to evaluate the beat-to-beat MBFV. RESULTS In the linear regression analysis of the M2-M4 data sequence, the slope between relative changes (compared with M1 values) in DCCV and DCflux, and those between the proceeding DCCV and the subsequent DCflux, were negative (R(2) > 0.40 for all; p < 0.05). CONCLUSION This is the first study to reveal a possible time-domain relationship between changes in MBF and MBFV parameters. Our results suggest that MBFV evaluated from the beat-to-beat LDF waveform is useful for monitoring the microcirculatory regulatory activities of arteriolar openings, and might therefore be particularly meaningful when evaluating treatment techniques or drugs aimed at improving microcirculatory perfusion.

Spectral analysis on the microcirculatory laser Doppler signal of the acupuncture effect

We aim to analyze the frequency content of skin blood flow signals recorded on Hoku following acupuncture stimulation (AS). Each experiment involved recording a 20-minute control-data sequence and two effects data recorded 0-20 and 50-70 minutes after stopping AS, respectively. 4-level Haar-wavelet transform was performed on the measured LDF signals, and periodic oscillations with five characteristic frequency peaks were obtained within the frequency interval: 0.0095-0.021, 0.021-0.052, 0.052-0.145, 0.145-0.6, and 0.6-1.6 Hz, respectively. Band proportion and DC component of the flux signal were calculated to elucidate the effects following AS. At Hoku, the DCflux was significantly increased, the band proportion of the 1st and the 2nd frequency band were significantly decreased, and that of the 5th band was significantly increased following AS. Our results facilitate a non-invasive method to evaluate sympathetic control of peripheral vascular activity between the acupoint and non-acupoints, which may be important for studying the therapeutic effects of AS.

Past, Present, and Future of the Pulse Examination (脈診 mài zhěn)

The pulse examination (脈診 mài zhěn) is a unique diagnostic approach of Traditional Chinese Medicine. The description of pulse examination in the history of Traditional Chinese Medicine is full of amazement and mythology. After researching in hemodynamics and investigating in clinical application for three decades, this article describes the development and the merits and demerits of pulse examination. The experiences of the ancients are tried to be illustrated with modern knowledge and language. As the theory of resonant blood circulation is discovered, Traditional Chinese Medicine could be on the shoulder of Newton and then lead the development of modern medicine. Hope the tool of pulse examination constructed according to eigen-vector with specific time domain and position can bring the running water for Traditional Chinese Medicine. Quantitative research could overcome the plight of analog logic qualitative research, and therefore bring new health revolution.

Effects of Captopril on Specific Harmonic Indexes of the Peripheral Pressure Pulse Waveform

There were evidences that the blood pressure measured on the radial artery under some vasodilators treatments will overestimate than which measured on the central artery. Our previous studies infer that the harmonic proportion of the 4th harmonic (C4) of the peripheral pressure pulse waveform could be an index related to the peripheral vascular tone. In this study, we used a vasodilator drug, captopril to verify the relationship between C4 and vasoactive drug. Thirteen male Wistar Kyoto rats weighing 270 to 350 grams were studied. The blood pressure waveforms measured on the tail artery were averaged every 10 minutes and Fourier transformed into frequency domain. The data measured 20 minutes before captopril (0.83mg/1kg) injection was used as control. Four 10 minutes after-drug data sets were compared with the control. The diastolic (DBP) and systolic (SBP) blood pressures decreased rapidly after captopril injection. The mean pulse pressure A0 has the same decreasing trend but less conspicuously. The harmonic proportion of the 4th harmonic decreases at the beginning but then increases dramatically. These results suggest that C4 could be an index related to the peripheral vascular tone. We present a harmonic based pulse waveform analysis method to provide a peripheral pressure waveform index which may be used to estimate the cardiovascular risk.