Equivalent Lever Principle of Ossicular Chain and Amplitude Reduction Effect of Internal Ear Lymph / 生物医学工程学杂志

This paper makes persuasive demonstrations on some problems about the human ear sound transmission principle in existing physiological textbooks and reference books, and puts forward the authors' view to make up for its literature. Exerting the knowledge of lever in physics and the acoustics theory, we come up with an equivalent simplified model of manubrium mallei which is to meet the requirements as the long arm of the lever. We also set up an equivalent simplified model of ossicular chain--a combination of levers of ossicular chain. We disassemble the model into two simple levers, and make full analysis and demonstration on them. Through the calculation and comparison of displacement amplitudes in both external auditory canal air and internal ear lymph, we may draw a conclusion that the key reason, which the sound displacement amplitude is to be decreased to adapt to the endurance limit of the basement membrane, is that the density and sound speed in lymph is much higher than those in the air.

Effect of hemorheology on ultrasonic doppler blood flow spectrum diagram / 生物医学工程学杂志

The present research aims to point out the long-existing defect of analyzing the spectrum diagram only from the perspective of haemodynamics instead of haemorheology. In the light of the theories of haemodynamics and haemorheology, the causes of spectrum diagram formation of carotid artery blood at the rapid and slow flow can be clarified completely and accurately. Four conclusions have been drawn in the end. As long as the velocity gradient is large enough, obvious red blood cells concentrate to the shaft even in the big or bigger blood vessels; the spectrum diagram is the powerful proof of the two phase flow model of blood; the spectrum diagram can be completely and accurately analyzed only by combining haemodynamics with haemorheology; and only when the red blood cells concentrate to the shaft, the big or bigger blood vessels can be regarded as haemogeneous fluid.

Synchonization of the blood flow rate in arterial with the changing rate of space of blood pressure with time / 生物医学工程学杂志

In physiology-related books, there are many relationship curves about blood flow rate in arteries and blood pressure changes with time, but there are not much explanation about such relationship. This is the very the question that the present article tries to answer. We clarified the relations between blood flow rate and blood pressure gradient using the experimental curves as the basis, using Poiseuille Law and relative knowledge of phisics and mathematics, and using analysis and reasoning. Based on the study, it can be concluded that in every course of cardiac cycle, the blood flow rate of any section in artery blood vessel is roughly synchronized with changing rate of space and time of the blood pressure, but blood flow rate is not synchronized with blood pressure.

Production and law of variation of the pleural cavity intrinsic pressure and the pressure of alveolar wall during respiratory process / 生物医学工程学杂志

All physiologic textbooks deal with pleural cavity pressure, alveolar wall pressure and pressure inside the lung, but they have not stated these ideas clearly. The present study reveals production and Law of variation of the intrinsic pressure of pleural cavity, the pressure of alveolar wall and the intrinsic pressure in the alveoli. Pleural cavity intrinsic pressure is produced by the pressure from pleura expanding or compressing force of the lungs. When the lungs calmly inhale, the thorax expands, pleural cavity negative pressure increase. When the lungs calmly exhale, thorax reduces, but thorax and lungs are still in the extended state, pleural cavity is still in negative pressure. With thorax reducing, negative pressure decreases. When the lungs are at the forced expiration, the lung pleura and wall pleura extrude pleural cavity, only to produce positive pressure. The pressure of alveolar wall is the algebraic sum of the intrinsic pressure of pleural cavity, the intrinsic pressure of pulmonary tissue and the additional pressure of alveolar wall. We did the calculation of additional pressure on the alveolar wall by using Laplace formula of spherical elastic membrane. The intrinsic pressure of alveoli depends on the moving speed or slowness of expansion or compression of alveolar wall and the size of trachea resistance.

Summing up Experiences and Pushing the Development of Clinical Hemorheologic of my Nation in Depth / 中国医学物理学杂志

Objective: Pushing the development of scientific research, education and clinical applying of hemorheologic in eath part comprehensively and in depth. Methods: Summarizing the experiences, lessons and questions in scientific research, edu-cation and clinical applying of hemorheologic in twenty and more years, clarifying the harm of high viscosity to health. Re-sults: Stating the foundation, necessity and feasibility of the overall and deep development have been possessed. Conclusions: Hemorheologic can be developed comprehensively and in depth provided that studying good experiences, cultivating talent, playing the role of learning organizations and conquering the existing questions.

A tentative analysis on the principle of capillary tube viscometer / 生物医学工程学杂志

As there is justification showing that Poiseuille's Law is not suited for vertical Capillary tube viscometer, Poiseuille's Law has not been used to deduce the calculation formula for measuring liquid viscosity by means of vertical Capillary tube viscometer; it can only be used to deduce the calculation formula for measuring liquid viscosity by horizontal capillary tube viscometer. In this article, we explained the extension of Poiseuille's Law to deduce the Calculation formula for measuring liquid viscosity by using shallow pool and deep pool Capillar tube viscometer, and so corrected the mistakes in using Poiseuille's Law for a long time.