HARVARD 50-9513 Operating And Maintenance Instructions Manual

Isolated preamplifier

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Operating and Maintenance

Isolated Preamplifier

Instructions

Harvard

Catalog Number:

50-9513

Publication

Revision

Date

84 October Hill Road

Massachusetts 01746

Tel.:

(508) 893-8999

Fax:

(508) 429-5732

e-mail:

bioscience

@harvardapparatus.com

Web Site: harvardapparatus.com

12/28/94

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Summary of Contents for HARVARD 50-9513

Page 1 84 October Hill Road Massachusetts 01746 Tel.: (508) 893-8999 Fax: (508) 429-5732 e-mail: bioscience @harvardapparatus.com Web Site: harvardapparatus.com Operating and Maintenance Instructions Harvard Isolated Preamplifier Catalog Number: 50-9513 Publication Revision Date 12/28/94...
Page 2: Table Of Contents
Specifications ..............Operating Procedure: Recording with Electrodes .......... Siting and Fixing the Electrodes ........ 5 - 7 Use with the Harvard Modular Universal Oscillograph ..........8 - 9 Use with the Harvard Student Oscillograph ............ 10 - 11 Problems ................
Page 3: Caution/Warning Statement
AFTER USE ON EACH SUBJECT to reduce the chance of skin infections or blood-carried diseases being transmitted. Introduction The Harvard Isolated Preamplifier has been designed for ECG (EKG), EMG, and ENG (EOG) recording with subject isolation. The front end of the preamplifier is a battery operated opto-isolator.
Page 4: Specifications
DC level control; battery level indicator; choice of DC or AC coupling Rear Panel Coupling lead for use with Harvard instru- ments; battery housings HARVARD I s o l a t e d P r e a m p l i f i e r...
Page 5: Operating Procedure
DC voltage will develop at the electrode site which may well “swamp” the input of the amplifier, causing the sig- nal to get progressively smaller until it finally disappears. This can be countered by connecting the 50-8390 Harvard Capacitor Box between the electrodes and the Isolated Preamplifier.
Page 6: Siting And Fixing The Electrodes
Siting and Fixing the Electrodes Fig. 2 below shows a suggested positioning of electrodes for ENG (EOG). Note the positioning of the reference electrode (or zero volt electrode). This electrode (within reason) can be placed anywhere. To 3-pin socket on Isolated Preamplifier –...
Page 7 Siting and Fixing the Electrodes (continued) Fig. 4 on this page shows the conventional positions of electrodes for recording ECG. You will notice that the patient’s RIGHT LEG is the 0 volt reference. Essentially an ECG can be recorded from any part of the body, but unless the conventional positions are used, the interpretation of the results would be difficult.
Page 8 – – – – – –...
Page 9: Universal Oscillograph
Connect the electrodes to the Isolated Preamplifier using either the 3-lead input cable or the ECG limb cable. With reference to the Harvard Modular Universal Oscillograph Instruction manual section 3.4.0, follow steps 1 to 13 inclu- sive.
Page 10 The amplitude of the waveform can be increased or decreased by using the Oscillograph's GAIN control [W] and the Preamplifier's GAIN control (6). If either of the GAIN controls are re-adjusted, it may be necessary to adjust the Preamplifier's DC LEVEL control (3) to bring the pen back to the center of the chart.
Page 11: Student Oscillograph
Connect the electrodes to the Isolated Preamplifier using either the 3-lead input cable or the ECG limb cable. With reference to the Harvard Student Oscillograph Instruction manual section 3.4.0, follow steps 1 to 13 inclu- sive.
Page 12 Measure the height of the waveform in mm. Let this value equal h. Let g equal the gain selected on control (6). Therefore the waveform (mV) = d x h CHART SPEED POWER HARVARD EVENT CAL. 0-1V. DIRECT INPUT GAIN INTERFACE PEN ZERO A.C.
Page 13: Problems
Problems If “noise” is seen superimposed on the waveform, then check the following: Have you sited the electrodes correctly? Check that the elec- trodes are not sited on excessive fat. Check that they are not sited over large muscles, otherwise, EMG will also be displayed.
Page 14: Customer Contact Addresses
U.K. office direct (telephone number, fax number, telex number and address below) stating the nature of the fault and the approximate date of purchase, if possible. ENGLAND Harvard Apparatus Ltd. Telephone: (0732) 864 001 Fircroft Way...