blood pressure/part 2
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Posts: 46,084
Yes, and very good advice. Chair was orginially designed, built and demo'ed
in 1967 and 1968 when FDA standards did not exist. Seem to recall that EKG
amplifier was battery powered and used matched N-channel JFET's for inputs
driving ua709 op amp and originally designed in 1966 when 709's were $70
each. Many thanks for passing along your thoughts and comments. Today's
design would be much different and probably would not attempt to use without
supervision. Burt
in 1967 and 1968 when FDA standards did not exist. Seem to recall that EKG
amplifier was battery powered and used matched N-channel JFET's for inputs
driving ua709 op amp and originally designed in 1966 when 709's were $70
each. Many thanks for passing along your thoughts and comments. Today's
design would be much different and probably would not attempt to use without
supervision. Burt
Comments
bought before FDA regulation. Shortly after I joined an Eye & Ear Hospital,
an "old, but works fine" machine for recording eye movements failed while
used for testing a beautiful young woman. She left the hospital with a
prominent burn mark on her lower forehead. Next stop was her attorney. I
was not involved with this, but personally observed the effects.
Similar disasters are much less likely with current Stamp/PIC projects,
particularly if battery powered, but isolation chips are now plentiful at
low cost to prevent them.
Dennis
Original Message
From: burtsz@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DeYwFxkv_z5XqfdMFwmuZlF1Xm4lwJHpyE-qEanTzNBUwil2Ny4RkLQTV3ArCz0W2ExHWum1LBmK]burtsz@a...[/url
Sent: Monday, January 15, 2001 11:37 AM
To: basicstamps@egroups.com
Subject: Re: [noparse][[/noparse]basicstamps] blood pressure/part 2
Yes, and very good advice. Chair was orginially designed, built and demo'ed
in 1967 and 1968 when FDA standards did not exist. Seem to recall that EKG
amplifier was battery powered and used matched N-channel JFET's for inputs
driving ua709 op amp and originally designed in 1966 when 709's were $70
each. Many thanks for passing along your thoughts and comments. Today's
design would be much different and probably would not attempt to use without
supervision. Burt