ABSTRACT
In order to obtain the three-dimensional pulse information and blood pressure waveform needed in the study, a radial artery simulation platform with programmable controlled injection pump as the core was constructed by using the circulation theory of human cardiovascular system and pulse wave formation mechanism. Gaussian function model was selected to synthesize multi-type pulse wave to program and drive the platform. The three-dimensional pulse information and blood pressure waveform of the simulated radial artery were collected by binocular visual pulse detection system and pressure transmitter respectively, and the platform stability and repeatability were tested by Pearson correlation. The experimental results show that the radial artery simulation platform is stable, reliable and repeatable, and can generate multiple types of three-dimensional pulse information and blood pressure waveform at the simulated radial artery. The platform is simple in structure, low in cost, and produces many types of pulsating flow. It provides an experimental research platform for revealing the relationship between the three-dimensional pulse information of radial artery and the change of pressure inside the vessel, as well as the prediction of blood pressure waveform from the three-dimensional pulse information.
Subject(s)
Humans , Blood Pressure , Computer Simulation , Heart Rate , Radial Artery , Vital SignsABSTRACT
Objective To study the injury cases of armored biological target by bullet and its causes, and provide references for revealing the wound mechanism of armored human by bullet and the corresponding medical treatment. Methods A 60 kg live pig was selected as the biological target, and the testing physical quantity and specific location within the biological target were identified by reference to the vulnerability in the head and chest of the soldier with armor. Three rounds of 9 mm Bala Baerum pistols in 25 meter-range were shot, respectively, on the head and chest of the biological live target with armor, and the multi-mechanical parameters (acceleration, pressure, loads, etc.) that played an important role in blunt trauma of armored biological target under pistol impacts were measured. Results (1) Blunt injury to the head of the biological target by pistol generated negative pressure pulse inside the calvarium with far reaching effects, and pressure pulse appeared in the spine and carotid; (2) Blunt injury to the chest of the biological target by pistol caused high-G impact on the heart, with high pressure wave in the lungs. Conclusions The measurement results in this study provided the basis for quantitatively understanding the injury mechanism of the pistol impacted by live armored target.
ABSTRACT
Objectives: To determine the effect of hot bathing on blood circulation, we analyzed pressure wave using Wave Intensity (WI), which is defined as changes in blood pressure (dP)×changes in blood flow velocity (dV) during hot bathing, as the index for assessment.<br>Methods: Using a combined Doppler and ultrasonic echo-tracking system, we recorded changes in vascular diameter (dD) and dV of the common carotid artery simultaneously in six healthy subjects before (Pre-bathing), during (Bathing), and 10 minutes after bathing (41°C) (Post-bathing). We then measured the product of their changes at fixed intervals as WI and evaluated the positive component of the early systolic phase (FE) (representing the forward-traveling pressure wave), negative components following FE (B) (representing the reflection pressure wave), and the appearance time of (RT). RT was measured as the percentage ratio.<br>Results: 1) The magnitudes of FE and B tended to decrease during 10min of bathing (Bathing) and recover to the level of the pre-bathing stage after 10min of bathing. 2) The value of RT measured after 10min of bathing (Post-bathing) was significantly longer than the level before bathing (Pre-bathing).<br>Conclusion: The effect of the reflection pressure wave (i. e., the after load on the vascular system) decresses during hot bathing. We can thus conjecture that the time phase of appearance of the reflecting pressure wave is delayed when the arrival time of the forwardtraveling pressure wave to the periphery is delayed and the propagation of the reflection pressure wave from the periphery slows down due to the expansion of vessels during hot bathing. Hot bating can therefore be expected to reduce after loads of healthy adult subjects.
ABSTRACT
We evaluated one month follow-up results of the 12 adult patients who showed ventriculomegaly in the aspects of symptoms. Evans ratio, periventricular low density, grades of radio-isotope cisternography, and grades of continuous intracranial pressure monitoring that were classified on the pressure wave and basal pressure level. The grades of continuous ICP monitoring were compared to the grades of radio-isotope cisternography. History, symptoms, CT findings, and radio-isotope cisternography are often helpful to decide shunt operation but sometimes continuous intracranial pressure monitoring gives invaluable information.
Subject(s)
Adult , Humans , Follow-Up Studies , Intracranial PressureABSTRACT
The effect of alterations in the respiratory pressure wave forms in various I:E ratio during mechanical ventilation were studied in 9 children who had received open heart surgery. The patients were ventilated at I:E ratio of 1:3, 1:2, 1:1, 2:1 and 3:1 and wave forms of aeeelerating triangular, rectangular and decelerating triangular at random order. The minute ventilation and peak inspiratory pressure were remained constant. The F was 1.0. In this study, the only positive findings were that the use of rectangular and decelerating triangular wave form in I:E ratio of 1:2 resulted in decreased alveolar-arterial oxygen difference, 23.6% and 21. 1%, respectively, compared with the wave form of accelerating triangular.