Path Loss Measurement and Channel Modeling with Muscular Tissue Characteristics

Background: The galvanic coupling intra-body communication has low radiation and strong anti-interference ability, so it has many advantages in the wireless communication. Method: In order to analyze the effect of muscle tissue’s characteristics upon the communication channel, we selected the muscle of pig buttock as the experimental sample, and used it to study the attenuation property with the galvanic coupling intra-body communication channel along the parallel direction and the transverse direction relative to the muscular fibre line as well as on the surface of destroyed muscular fibre; the study frequency ranges from 1kHz to 10MHz.In the isotropic experiment, in order to destroy muscle’s fibre characteristics, we grinded the muscle four times, at least five minutes for each time. 0dbm sine-wave signal was input to measure the channel attenuation parameter S21 when the transmitter and the receiver were placed at different positions and different distances d1 and d2 (20mm, 40mm, 60mm), so as to analyze channel loss. Conclusion: Within the same frequency range and at the same communication distance, the maximum error of channel attenuation was 10dB; within the same frequency, as the communication distance was increased, the channel attenuation rose gradually, with 4dB increased every 20mm. The conclusion provides the basis for building the theoretical model in the future.

Mathématiser l’anatomie: la myologie de Stensen (1667)

In his Elementorum Myologiae Specimen, Steno geometrizes “the new fabric of muscles” and their movement of contraction, so as to refute the main contemporary hypothesis about the functioning of the muscles. This physiological refutation relies on an abstract representation of the muscular fibre as a parallelepiped of flesh transversally linked to the tendons. Those two features have been comprehensively studied. But the method used by Steno, as well as the way he has chosen to present his physiological results, have so far been neglected. Yet, Steno’s work follows a true synthetic order, which he conceives as a tool to separate uncertain anatomical “elements” from the certain ones. We will show that the true understanding of this “more geometrico” order is the only way to avoid frequent misconceptions of the scientific aim pursued by Steno, which is neither to give a mathematical explanation of the functioning of the muscles, nor to reduce the muscles to some mathematical shapes.

On the Structure and Contraction of Striped Muscular Fibre of the Crab and Lobster

(Abstract)The author gave an account of the microscopical appearances of striped muscle of the crab and lobster. The muscle of the crab and lobster is suitable for investigation because of the comparatively large size of the structural elements, and the readiness with which the sarcous matter can be fixed and otherwise prepared in different conditions. The author is entirely opposed to the opinions expressed by Melland, and more recently by Gehuchten, regarding the structure of the sarcous matter, and maintains, as he did at the International Medical Congress in 1881 (Transactions International Medical Congress, 1881, vol. i. p. 270), that the sarcous matter essentially consists of contractile fibrils, with an interstitial substance between them—an opinion previously expressed by Kölliker and others, and recently supported by Rollett.

XXI. Physiological action of the bark of erythrophleum guinense (casca, cassa, or sassy bark)

1. It diminishes oxidation, and thus prevents fresh vegetable tissues from communicating a blue colour to tincture of guaiac. 2. It does not hinder the development of the yeast-fungus nor the germination of seeds. Penicillium grows freely in a solution of it. 3. A watery solution of the alcoholic extract prevents the development of Bacteria , but one of the watery extract does not do so. 4. It does not destroy the life of Bacteria or Infusoria. The motion of cilia is not arrested by it. 5. It arrests amœboid movement in leucocytes. 6. It has no action on fresh muscular fibre; but muscular tissue, when kept in a solution of the alcoholic extract for some days, undergoes extensive fatty metamorphosis, but does not become putrid.

I. On the structure of striped muscular fibre

After premising that, owing to the rapidity with which changes set in after death, the subject in question can only properly be worked out whilst the muscular fibres are still living, the author proceeds to give the result of his investigations of the tissue in this condition. The animal employed was the common large water-beetle, the muscles of the legs being taken. These were examined entirely without addition, being either teazed out upon a glass slide in the ordinary way and covered with thin glass, or else prepared upon the latter, which was then inverted over a ring of putty after the method introduced by Strieker.