Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 35 (1979), S. 125-130 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Two-terminal electronic circuit neuron model is described. The model has time-variant voltagecurrent characteristics of an excitable membrane. Corresponding equivalent circuit is shown by the use of time-invariant elements as a voltage-controlled oscillator. The design principle of the model is outlined. Two application examples are demonstrated: (1) Simulator of the excitable membrane for the investigation of a voltage-clamp instrument, which works in the low current and low voltage region. (2) Circuit model for an electric organ of a weakly electric fish, Apteronotus.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Solid State Electronics 11 (1968), S. 981-983 
    ISSN: 0038-1101
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 135 (1980), S. 283-290 
    ISSN: 1432-1351
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Electric organ discharges (EOD) were measured in a wave-type electric fish,Apteronotus, with an array of electrodes. 2. The EOD waveform observed in the transient area (area where the equipotential lines converged) was a triphasic one in comparison to a biphasic one in the rest of the area. Electronic circuit simulation suggested that the triphasic waveform resulted from incomplete electrocyte synchronization within the electric organ. 3. The EOD field was obtained by computer simulation using the finite-element-method. The simulated results were used for calculation of the transepidermal potential difference distribution. This distribution is discussed with respect to sensitivity differences of electroreceptors in various parts of the fish.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-2013
    Keywords: K+ channels ; Acinar cells ; Ensemble noise analysis ; Current relaxation ; Patch-clamp whole cell recording
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The K+ channel in rat parotid gland acinar cells were investigated by ensemble current noise analysis in single isolated cells employing the giga-seal whole cell current recording mode. Sets of 20–40 identical de- and hyperpolarization voltage steps were applied and the resultant current records were processed by computer to obtain the mean and the variance of the current. The time-course of the mean current could be fitted by the sum of two exponentials, suggesting a 3-state model. The simplest plausible hypothesis is a model with one open and two closed states. Assuming this model, the relationship between the variance (σ2) and the mean current (I) could be fitted by the function σ2/I=i−I/N. The estimated single channeli/V-relations were similar to those taken from single channel current recordings, and the size of the population of channels per cell (N) was 76±26 (n=12). The validity of the model was tested by a successful simulation of the time-course of the variance.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1741-0444
    Keywords: Artificial respirator ; Electrical stimulation ; Respiratory control ; Synchronised stimulation ; Nerve impulses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Sommaire Un nouveau type de respirateur électrophrénique synchrone, développé par nos soins, a été appliqué à des chiens souffrant d'une défaillance respiratoire incomplète, en bloquant la lère corde thoracique ainsi que les branches C6 et C7 des deux nerfs phréniques (en incluant quelquefois une branche C5 unilatérale). Ce respirateur a stimulé le moignon distal du nerf phrénique en synchronisation avec les impulsions faibles partant du moignon proximal du nerf, permenttant ainsi la régulation convenable de la respiration. Le volume oxygénant minime et les pressions partielles des gaz expirateurs de fin de respiration se trouvaient automatiquement réglés par le respirateur pour passer de l'état d'hypoventilation au niveau normal de la régulation accompagné d'un dépassement et d'oscillations amorties. Les gaz sanguins artériels se sont également rétablis d'une façon satisfaisante. L'aspiration de fortes concentrations d'acide carbonique pendant la respiration électrophrénique synchrone a provoqué des réponses similaires à celles observées pour les chiens normaux. Ainsi on a trouvé que le respirateur électrophrénique synchrone pouvait fonctionner comme élément du système de réaction respiratoire.
    Abstract: Zusammenfassung Wir entwickelten ein neues synchrones elektrisches Beatmungsgerät für das Zwerchfell, das auf Hunde mit unvollständigem, Atmungsausfall angewandt wurde, der durch eine Blockierung des 1. thorakalen Stranges und der Verzweigungen C6 und C7 von beiden Zwerchfellnerven verursacht worden war (manchmal einschließlich einer einseitigen C5-Abzweigung). Dieses Atemgerät reizte den distalen Stummel des Zwerchfellnerven synchron mit den schwachen Impulsen vom proximalen Stummel des Nervs, so daß sich eine Geeignete Steuerung der Atmung ergab. Das äußerst geringe Beatmungsvolumen und die Teildrücke der ausgeatmenten Gase am Ende des Atemluftvolumens wurden atuomatisch durch dieses Beatmungserät vom Zustand der Unterbeatmung in eine normale Steuerung verwandelt, verbunden mit Übersteuerung und gedämpften Schwingungen. Die Gase des arteriellen Blutes erholten sich hinreichend von der Unterbeatmung. Bei Einatmung von starken Kohlendioxydkonzentrationen während der synchronen elektrischen Zwerchfellbeatmung ergaben sich ähnliche Reaktionen wie auch bei normalen Hunden beobachtet wurden. Auf diese Weise wurde festgestellt, daß das synchrone elektrische Beatmungsgerät für das Zwerchfell als Element der Beatmungsrückkoppelung eingesetzt werden könnte.
    Notes: Abstract A new type of synchronous electrophrenic respirator developed by the authors has been applied to dogs with incomplete respiratory failure produced by blocking the 1st thoracic cord and the C6 and C1 branches of both phrenic nerves (sometimes including a unilateral C5 branch). This respirator stimulated the distal stump of the phrenic nerve synchronously with the feeble impulses from the proximal stump of the nerve, resulting in a suitable control of respiration. The minute ventilatory volume and the partial pressures of the expiratory end-tidal gases were adjusted automatically by this respirator, from the state of hypoventilation to the normal control level, accompanied by an overshoot and damped oscillations. The arterial-bloodgases also exhibited a satisfactory recovery from the hypoventilation. The inhalation of high concentrations of carbon dioxide during the synchronous, electrophrenic respiration produced similar responses to those observed in normal dogs. Accordingly, it was found that the synchronous electrophrenic respirator could operate as an element of the respiratory-feedback system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 23 (1985), S. 23-27 
    ISSN: 1741-0444
    Keywords: Classification ; Mechanoreceptor ; Multichannel ; Multimicroprocessor system ; Multi- unit ; Nerve impulse ; Real-time processing ; Waveform analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract A new system for the online real-time waveform separation of the nerve impulses recorded from multichannel extracellular electrodes placed to the peripheral nerve trunk has been developed using two microprocessors and a graphics computer. One microprocessor (Intel 8085) performs nerve impulse detection and the other (Intel 8086) separates nerve impulses by clustering in the two-dimensional histograms representing the distribution of the parameters extracted from their waveforms. System performance was examined with two channel impulses recorded from the nerve trunk innervating the Sartorius muscle of a frog. These data could be classified into 6–8 different groups in real time.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 14 (1976), S. 387-394 
    ISSN: 1741-0444
    Keywords: Articial respirator ; Electrical stimulation ; Respiratory control ; Synchronised stimulation ; Nerve impulses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Sommaire On a développé un nouveau type de respirateur électrophrénique pour effectuer la stimulation synchrone du nerf phrénique avec les impulsions correctes. Les artéfacts de mode commun tels que l'ECG, l'EMG et les 50 Hz sont supprimés par un amplificateur différentiel ayant un taux élevé de réjection du mode commun et une forte impédance d'entrée. Des artéfacts à mode différentiel partant d'électrodes bipolaires sont éliminés par des filtres passe-haut et des circuits de logique étudiés å l'aide des caractéristiques des impulsions du nerf phrénique. Cette méthode permet de capter les impulsions du nerf sans endommager le tronc du nerf phrénique. Une tension alternative bidirectionnelle sert à stimuler le nerf afin d'obtenir une respiration naturelle. Le respirateur est capable de guérir l'hypoventilation centrale sans perturber le système de réaction respiratoire.
    Abstract: Zusammenfassung Es wurde ein neues elektrisches Atemgerät zur Beatmung des Zwerchfells entwickelt, das den Zwerchfellnerv synchron mit den richtigen Impulsen stimuliert. Gleichtaktartefakte wie EKG, EMG und 50 Hz werden durch einen Differenzverstärker mit niedrigem Störpegel, mit starker Gleichtaktunterdrückung und hoher Eingangsimpedanz unterdrückt. Differentialtakt-Artefakte von zweipoligen Elektroden werden durch Bandpaßfilter und logische Schaltungen ausgeschaltet, die mit Hilfe der Merkmale von Zwerchfell-Nervenimpulsen konstruiert wurden. Durch dieses Verfahren können die Nervenimpulse ohne Beschädigung des Zwerchfell-Nervenstranges übernommen werden. Zur Stimulierung des Nervs wird eine zweiseitig gerichtete Spannung verwendet, um eine natürliche Atmungswirkung zu erzielen. Dieses Atemgerät hat die Möglichkeit, eine zentrale Unterbeatmung ohne Störung der Rückkoppelung für die Atmung zu beheben.
    Notes: Abstract A new type of electrophrenic respirator has been developed, which synchronously stimulates the phrenic nerve with the correct impulses. Common-mode artefacts such as the e.c.g., e.m.g., and 50 Hz are suppressed by means of a low-noise differential amplifier with high common-mode rejection and a high-input impedance. Differential-mode artefacts from bipolar electrodes are eliminated by means of band-pass filters and logic circuits, which have been designed with the aid of the characteristics of the phrenic nerve impulses. By this method, the nerve impulses can be picked up without damaging the phrenic nerve trunk. An alternating bidirectional voltage is used for the nerve stimulation to obtain a natural breathing action. This respirator has the possibilities of curing central hypoventilation without disturbance of the respiratory feedback system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...