THE PHOTO-RECORDER WITH A PROGRAMMABLE RELAY MECHANISM AND AN ORIGINAL MAKER

Albertin Sergey Victorovich
Pavlov Institute of Physiology of the Russian Academy of Sciences
St.-Petersburg, Russia, Senior Researcher

Abstract
Present paper describes an original technique aimed to overcome some problems of rigid closed-loop experiment by introducing in electrical circuit of automated computer system the specially developed electro-mechanical device – programmable photographic recorder, equipped with special marker. This photo-recorder was designed to provide the registration of single and superimposed bioelectric potentials, their automatic marking, as well as programmable switching of different devices necessary for testing of object and recording reliable evoked responses.

Keywords: alterna-tives in data recording and marking, automated electrophysiological experiment, bio-feedback and searching experiments, programmable photographic recorder


Category: 03.00.00 Biology

Article reference:
The photo-recorder with a programmable relay mechanism and an original maker // Modern scientific researches and innovations. 2015. № 9. P. 1 [Electronic journal]. URL: https://web.snauka.ru/en/issues/2015/09/57939

View this article in Russian

INTRODUCTION

In the last few years a number of publications were devoted to the development of different computer programs to arrange an optimal automated closed-loop neurophysio-logical experiment to provide the selection and recording free from artifacts neural res-ponses without participation of experimenter (Benda et. al., 2007; Benda, Grewe 2009; Mohri et. al., 2012; Nowotny et. al., 2013).

However, so-called the closed-loop computer systems have the serious restrictions, particularly in animal experiments, which exclude possibilities to instruct the animals like humans, allowing to be relaxed to get more standard neuronal responses with minimal number of artifacts.  Besides, it is well known that under computer neural summarizing  the peculiarities of individual neural responses are suppressed, on  another hand many unwanted brain potentials (e.g. paroxysmal discharges, sleep spindles, muscle activity related artifacts, etc.) results to much troubles under computer selection and collection of biopotentials as well as interpretation of data obtained (Gewins, 1987; Regal, 1989). That’s why a permanent visual monitoring of responses obtained, their in-dication  and selected analysis  are necessary in  animal experiments for reliable estimation, correction and recording of data both in digital and native, analogous forms.

Closed-loop computer systems also do not allow carrying out the so called searching experiments which periodically require to interrupt of experiment for urgent performing the necessary procedures related to changes of animal state, appearance of unwanted artifacts or receiving of extraordinary data.  Besides, the closed-loop computer systems do not have the reliable duplicate technical means to continue carrying out of full-scale experiment with keeping of obtained data in case of possible computer problems, i.e. ope-rational system breaking, working program errors or troubles of an input system, which transforms primary neural responses in digital form.

Solution of above mentioned problems under using the standard closed-loop com-puter systems for selection and recording of neural responses remains to be problematic.

DEVICE CONSTRUCTION

We have developed an original technique aimed to overcome some problems of rigid closed-loop experiment by introducing  in electrical circuit of  automated computer  system the specially developed electro-mechanical device – programmable photographic recorder designed to provide the registration of single and superimposed bioelectric potentials, their automatic marking as well as program switching of different devices necessary for testing of object  and recording reliable evoked responses (Fig.1).

In contrast to standard photographic apparatus a new developed photo-recorder  is equipped with a program cam mechanism and an original marker. Cam mechanism drives photo-recorder and marking device and provides automatic switching of electric stimulation for testing of animal as well as switching the recording devices required for carrying out of  experiment.  Marking of  biopotentials is realized  by using  the selected frames of exposed photographic film. To do that the specially prepared transparent marking film  was introduced  through  additionally  made film channel into  the frame window of photo-recorder oriented  perpendicularly to exposed film (Fig. 1).

Photo-recorder  was developed on the basis of standard photo-camera. In our case we used the body of camera “TYP MFI-1” (Hungary) equipped with tube for attaching ca-mera to oscilloscope. This camera was fully reconstructed: photolock was removed, in the body of camera an additional film channel oriented perpendicularly to main exposed film was made, and a number of new electromechanical elements were additionаlly installed. As a result the developed  photo-recorder includes the following units (Fig. 1): an electric motor (M), joined via reducer with time lapse mechanism (1) and the mechanic cams C1 and C2 with pushers connected with sprang contact switches (CS);

Fig. 1. Electrokinematic scheme of photo-recorder; 1,6 – time lapse mechanism; 2 – start-up relay;

3 – start bottom of motor; 4 – photoprotocol of experiment; 5 –  exposed photographic film; 7 – recei-ving reels; 8 – supply reels; 9 –  retake pulley; 10 –  supporting panel; 11, 12 – connected  gears; M – electric motor; C1,2,3 – mechanic cams. CS 1,2,3 – contact switches of  cams. D – diode.  R – resistor. C – capacitor. FLD – flash-light device. Arrows – directions of films movements.

 start-up relay (2); start bottom of motor (3);  transparent photo film designed to provide manually writing of procedural notes which is a photoprotocol of experiment (4). It moves through supplementary made film channel by means of the film drive mecha-nism thereby providing contact with photosensitive layer of exposed photographic film (5). Film drive mechanism includes time lapse mechanism (6) attached to reducer of electric motor; receiving (7) and supply (8) reels, retake pulley (9) and supporting panel (10) for urgent writing of procedural notes. Flash-light device (FLD) was installed into the window of photo-recorder tube to illuminate marking notes on selected frames of exposed photographic film.

Photo-recorder is working in the following order (Fig. 1). Under pressing of bottom 3 an electric motor M fulfill one frame moving of exposed film in the beginning  of cam C1 half turn, the contact switch of cam C1 blocks a bottom 3 and charge an electric capacitor C of relay circuit, then in the end of cam C1 half turn it switch off an electric motor and provide contact closure of impulse feeding of relay 2 whose normally dis-connected contacts is in circuit of flash-light device. Transfer interrelations of gears 11 and 12 is 2:3. Thus half turn of 2-duple frame cam C1 corresponds to C2 turning on 120°.  The lamp of flash-light device is switching only after setting the marked frame of photo-protocol in a row of exposed film, marking every third frame of exposed film and leaving  two frames for biopotentials recorded in control and testing regimes. As a re-sult the Control-Test-Marks sequence is registered on the exposed film. Taking into account the equal speed both for exposed photographic film and the film of photo- protocol, the placing of marked frames is accurately provided.

Unused contact switches (CS) of cams C 2,3 and free relay contacts may be used for programmed switching of different  experimental  devices. The number of executive re-lays and program cams placed on motor reducer may be easily increased. Configura-tion and position of additionally included cams will depend on the aims of experiment and type of devices designed to be used (Albertin, 2005).

THE ADVANTAGES

  1. Programmable photo-recorder provides an actual visual selection of neural responses, their marking, photo registration and automatic guiding of all testing, controlling and recording devices included in circuit of electrophysiological experiment by means of programmable cam mechanisms and relay devices.
  2. Photo-recorder allows to unload the computer used in neurophysiological experi-ments from preparing and executing of many acts related to programming of experi-ment,  the data marking, switching the testing and recording devices, i. e. leaving computer  for collection and analysis of neural responses after procedural elimination of artifacts.
  3. Photo-recorder provides an automatic and semiautomatic marking of registered biopotentials: i.e. marking notes may be prepared in advance, before experimental session, as well as may be introduced urgently in running experiment.
  4. Photo-recorder is particularly suitable to carry out the so called searching experiment which periodically requires to interrupt the experiment for urgent performing the neces-sary procedures related to an animal state, appearance of unwanted artifacts and recei-ving of extraordinary data.
  5. Photo-recorder gives a good possibility to continue the carrying out of full-scale experiment with keeping of obtained data under the difference computer problems related to possible technical and/or program troubles.
  6. Photo-recorder may be successfully used in bio-feedback experiments in humans, which may be carried out in comfortable conditions: subject is relaxed, he is able to start testing himself by pressing the start-up bottom according to own current physical and psychological state, registered responses and instructive commands.

Acknowledghements    This research was performed in accordance with the program of the Russian Academy of Sciences:  «Innovative Technologies in Physiology and Experimental Medicine».

The priority of the developed programmable apparatus [1] was registered by Russian Federal Patent Service.


References
  1. Albertin S.V. (2005) An automatic device for recording and analyzing of evoked bioelectrical activity. Patent No 22660432005 (Russia).
  2. Benda J., GollischT., Machens C.K., Herz A.V.M. (2007) From response to stimulus: adaptive sampling in sensory physiology.  Current Opinion in Neurobiology  17: 430-436.
  3. Benda J., Grewe J.  (2009) Closed-loop electrophysiological experiments  and  metadata management with  RELAX and LabLog.  BMC Neuroscience   10: S2 (doi: 10. 1186/1471-2202-10-S1-S2).
  4. Gevins A.S. (1987) Overview of computer analysis // Methods of analysis of brain electric and magnetic signals. (Eds A.S. Gevins, A. Remond) Amsterdam, Elsevier.
  5. Mohri M., Rostamizadeh A., Talwalkar A.  (2012) Foundations of  machine learning. Cambridge MA The MIT Press.
  6. Nowotny T., Rospars J.P., Martinez D., Elbanna S., Anton S.  (2013) Machine learning for  automatic prediction of the quality of electrophysiological recordings.  PLoS ONE; 8 (12): e89838. doi:10.1371/journal.pone.0080838.
  7. Regal D. Human Brain electrophysiology. (1989)  Evoked potentials  and  evoked magnetic fields  in Science  and medicine. New York Amsterdam, London Elsevier.


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