Dear Michael and Remek,
My first reaction was to suggest that the three sizes originally were:
350 µm (= 0.0137795 inch ~ 0.014 inch)
450 µm (= 0.0177165 inch ~ 0.018 inch)
and 900 µm (= 0.0354331 inch ~ 0.035 inch)
Cheers,
Pat Naughtin
Author of the ebook, Metrication Leaders Guide, that you can obtain
from http://metricationmatters.com/MetricationLeadersGuideInfo.html
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
helped thousands of people and hundreds of companies upgrade to the
modern metric system smoothly, quickly, and so economically that they
now save thousands each year when buying, processing, or selling for
their businesses. Pat provides services and resources for many
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and government metrication leaders in Asia, Europe, and in the USA.
Pat's clients include the Australian Government, Google, NASA, NIST,
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On 2009/09/17, at 14:15 , Michael Payne wrote:
Looks suspiciously like 3,5 mm, 4,5 mm and 9 mm. The web site http://www.heartsite.com/html/ptca.html
only talks about a 2-3 mm tube, what you saw could just be in
inches because of the guy who designed the package in the US.
Mike Payne
----- Original Message -----
From: Remek Kocz
To: U.S. Metric Association
Sent: Thursday, 17 September 2009 01:12
Subject: [USMA:45822] Interventional surgery, wires, and metric.
All of you are probably familiar with angioplasty, and that it
entails threading a thin catheter through one's blood vessel for the
purpose of expanding the blockage inside it. All catheters are
deployed along guidewires which range from 45 to 300 cm in length.
The guidewires, oddly enough, have their diameters measured in
inches. It seems to be a worldwide standard, since the packaging is
multilingual (not just NAFTA), and only inches are mentioned for
diameter, with 3 standard dimensions being 0.014, 0.018, 0.035"
Is anyone familiar with the origins of this? Is this the US wiring
industry forcing another inch-based standard on the world? Or some
sort of a holdover from 19th century?
Remek
