[June 2006]

These pages will be moving to http://members.optusnet.com.au

A new, miniaturised version of this project is under development, which will enable its use for 'holter monitor' purposes.


Owing to my discovery of some flaws in the electronic design of the original project from which mine was developed, it was withdrawn, not for safety concerns, but because its output was considered inaccurate. It is now considered that any devices constructed to that design SHOULD NOT BE USED.  Further amendments have been made (MAY 2005). 

A new system (above) has been devised which provides a reliable means of providing Electrocardiography inexpensively. It consists of a compact, battery-powered amplifier unit which can feed information obtained from normal ECG electrodes to just about any Windows or DOS equipped PC. However, certain safety considerations would apply to its use with any high AC voltage connected equipment, and possibly safety would be best ensured if it were used with a battery operated Notebook/Laptop machine. My unit is housed in a small plastic box measuring 150 x 35 x 180 mm., which contains an analog amplifier, digital sampler, and calibration parts. A small extra unit connected to the input socket provides a switching network for ECG lead selection. 
The analog amplifier may be assembled in several different forms, either as a proprietory built-up unit, kitset, or 'from scratch'. Full details for each option are shown in the next page. You will require fairly rudimentary skills in electronics assembly techniques, whichever option you choose.  If the kitset or built up unit is chosen you will need to assemble small additional modules to my design. 
I have chosen to use a small proprietary digital sampler, which is currently available from its manufacturer (August 2003), at very moderate cost. Alternatives to this would include oscilloscopes, and possibly various PC software packages which make use of the machine's sound-card to simulate oscilloscopes. These latter however can only be as good as the sound card, which may not have an adequate low end frequency response. Alternatively use a digital sampler of your choice.
It should be noted that as a retired Medical Practitioner with an interest , but NO EXPERTISE in Cardiology, Electrocardiography, or electronics, I present this project as something I consider to be of potential usefulness to professionals; but they should be guided by their own knowledge or the advice of qualified professionals in its use. I can accept no responsibility for any harmful effects caused by the use of devices made to this design, and while care has been taken to ensure safety in use, having regard to safety warnings in this document, it is the responsibility of the user to satisfy him/her self regarding safety before attempting to use the device. 

Links to other pages below: 

J. Michael Hayman MB.BS., LMSSA.(Lond)., 

12 Tindarra Avenue,

OCEAN SHORES

NSW 2483 AUSTRALIA

Tel/FAX: 61 2 6680 3739
(Also see EMAIL address below). 

Send comments/enquiries to: jmhayman@optusnet.com.au
 

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