Méthode ESAO ESAO method
Transcription
Méthode ESAO ESAO method
Méthode ESAO® ESAO® method Ref : 553 032 Français – p 1 English – p 5 Version : 6006 Cuve à nerf - support Nerve tank - support Méthode ESAO® Cuve à nerf - support Ref : 553 032 La stimulation peut être de différentes formes (choc, brûlures,…) mais le plus souvent, pour l’étude, il s’agit d’une stimulation électrique (facilement paramétrable). La réponse correspond à une dépolarisation qui parcourt la fibre et que l’on détecte son passage. Un nerf étant un ensemble de fibres, tous les PA ne se produisent pas simultanément, et on détecte les résultantes de tous les PA des différentes fibres. Lorsque la stimulation augmente, le nombre de fibres stimulées croit, ce qui correspond pour l’observateur à une augmentation de la réponse du nerf. Le phénomène est analogue pour le muscle, bien que le PA musculaire soit plus ample. ATTENTION : Vidange de la cuve La viscosité du liquide de Ringer peut parfois provoquer une rétention dans le robinet. La pointe d’une aiguille à dissection glissée dans le conduit du robinet rétablit l’écoulement du liquide. FRANÇAIS 4 ESAO® Method Nerve tank - support Ref : 553 032 The nerve tank – support is an essential element for the study of muscular or nervous activity. It is a sturdy device, perfectly suitable for electrophysiology. The system was completely redesigned to meet 2 specific objectives: To create a device that uses the current sensitivity of new ESAO sensors To propose cost effective equipment by combining two devices: the nerve tank and the animal support leg. Detection electrodes (nerve area) Swivelling lid Detection electrodes (muscle Passage for the thread to study the mechanical activity of the muscle Stimulation electrode Fixing needle for the knee Drain valve Rubber mat skid-resistant Fixing the frog (support) Stainless steel counterweight 1 Principle – description 1.1 Commissioning Use in insulated nerve preparation tank (or muscle-nerve): Place the tank and the rubber plate on the working area. The combination of a stainless steel counterweight and rubber mat makes the tank immobile. The tank is divided into two parts: one reserved for the nerve and the other (with a notch at its end) for the muscle. Connect the two cables of the stimulation circuit to the two outermost electrodes of the tank, negative on the outermost socket. Connect the two detection cables to the two other electrodes, negative closer to the stimulation electrodes. In case of a nerve-muscle preparation, make sure to remove all knee joints from the preparation. Place the nerve on the electrodes and fix the knee on the holding prong (blunted in the factory). Place the muscle on the detection electrodes. The clamping system is essential because of the sensitivity of the myograph adaptor of the ESAO system, which requires a fixed point for the isometric study. The thread fixed at the end of the muscle passes through the notch made at the end of the tank before getting back to the myographic system. The thread must be as less elastic as possible to avoid damping the muscular contractions. We recommend the thread with part no. 323 011 (25 m reel). ENGLISH 7 ESAO® Method Nerve tank - support Ref : 553 032 Add a suitable quantity of Ringer liquid so as not to touch the electrodes (a humid atmosphere increases the lifespan of the preparation). Close the lid by engaging the lug in the notch designed for it. Stimulator Toward computer Stimulation Muscle sensor Nerve tank support Use of the tank for animal support Place the tank on 4 blocks of the lid with the rubber support facing up. The animal (frog or rat) can be fixed on the rubber mat for dissection or onthe-spot study. 1.2 Technical specifications • Lid + tank: thermoformed Plexiglas o Dimensions: 173 x 110 x 57 mm o Weight: 950 g o Display case: white rubber (the tank is supplied with a second pre-pasted display case) o Counterweight: stainless steel o Electrode: chlorinated pure silver wire 12 electrodes fixed on 4 mm diameter sockets enable the use of standard connections. • Tank divided into two parts: o Nerve part: 8 electrodes 2 stimulation electrodes in steps of 5 mm 6 detection electrodes in steps of 5 mm o Muscle part: 4 detection electrodes in steps of 10 mm The separation is done by a narrowing in the middle wherein is a blunted holding prong for the knee (the device is supplied with a cork to protect the point). ENGLISH 8 ESAO® Method Nerve tank - support Ref : 553 032 • Rotating lid fixed on the tank: loss not possible • Recommended accessories: o Connecting cables with rear re-entry: Black batch of 5 length 50 cm Part no. 283 303 Red batch of 5 length 50 cm Part no. 283 304 Black batch of 5 length 100 cm Part no. 283 308 Red batch of 5 length 100 cm Part no. 283 309 o 1 litre of Ringer fluid Part no. 107 134 o Thread reel of 25 m Part no. 323 011 1.3 Maintenance After use, drain the Ringer fluid from the tank and rinse it with running water to prevent salt deposits. The viscosity of the Ringer fluid can sometimes cause retention in the valve. Inserting the point of a dissecting needle into the valve should resume the flow of the fluid. ATTENTION: Never clean the electrodes with a grinding medium. A fracture can appear if the electrodes have been subjected to significant torsional stresses. We can provide you with electrodes pre-fitted on the socket that would be easier to replace. Follow the following procedures: • Separate the tank from its counterweight by unscrewing the 4 retaining screws • Invert the tank and place it on the blocks of the lid • Unscrew the nut with an 8 mm open-end wrench • Remove the socket • Position the new electrode • Screw on the nut • Fix the tank on the stainless steel counterweight. 2 Experiment 2.1 Electrical activity of the nerves The role of the nerve is to transmit information in the form of coded electrical signals. A nerve fibre responds to every stimulation of a sufficient level by a typical, unique signal: the action potential (AP). This response is of the on-off type: if the stimulation is sufficient then there is an AP (linear stimulation), if it is insufficient (sub-threshold stimulation) nothing happens. The stimulation may be of different types (shocks, burns, etc.) but mostly an electrical stimulation is used for study (easily parameterable). The response corresponds to a depolarisation that passes through the fibre and its path is detected. ENGLISH 9 ESAO® Method Nerve tank - support Ref : 553 032 A nerve being a group of fibres, all APs are not produced simultaneously and the resultant of all the APs of different fibres are detected. As the stimulation increases, the number of stimulated fibres increases, which corresponds to an increase in the nerve response for the observer. A similar phenomenon occurs with muscles even though the muscular AP is greater. Nerve action potential artefact Muscle action potential Duration Amplitude Nerve Action Potential: 0.8 ms 2 mV EPP: 2 ms 0.5 mV Muscle Action Potential: 4 ms 2 mV Total duration 9 ms CAUTION Draining the tank: The viscosity of the Ringer fluid can sometimes cause retention in the valve. Inserting the point of a dissecting needle into the valve can resume the flow of the fluid. ENGLISH 10 ESAO® Method Nerve tank - support Ref : 553 032 3 After-Sales Service This material is under a two year warranty and should be returned to our stores in the event of any defects. For any repairs, adjustments or spare parts, please contact: JEULIN - TECHNICAL SUPPORT Rue Jacques Monod BP 1900 27 019 EVREUX CEDEX FRANCE +33 (0)2 32 29 40 50 ENGLISH 11 ESAO® Method Nerve tank - support Ref : 553 032 NOTES ENGLISH 12 Assistance technique en direct Direct connection for technical support Une équipe d’experts à votre disposition du Lundi au Vendredi (8h30 à 17h30) A team of experts at your disposal from Monday to Friday (opening hours) ● Vous recherchez une information technique ? ● You’re looking for technical information ? ● Vous souhaitez un conseil d’utilisation ? ● You wish advice for use ? ● Vous avez besoin d’un diagnostic urgent ? ● You need an urgent diagnosis ? 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