Wednesday, June 28, 2017

1950s: The first peak flow meter

Wrights original peak flow meters (circa 1950s)
If you're an asthmatic you may not be familiar with Dr. Martin Wright, but you probably are familiar with an instrument he invented:  the peak flow meter.  It was a convenient, inexpensive, hand held tool that could be used by patients at home or in the hospital setting to assess the effects of bronchitis and asthma.  

It was first introduced in the 1950s by London physician, Dr. Martin Wright, of the Clinical Research Center at Northwick Park Hospital.  It was an instrument specifically designed to measure 'peak flow,' or the amount of air that can be forced out of a patient's lungs after a maximum inhalation.  

The original Wright Peak Flow Meter was a large, heavy, clock shaped device that was too expensive for the common person to have at home. It was generally used in hospitals to assess patients. It worked by the patient blowing air into the meter, and this air rotated a pointer on a dial against the resistance of a spring. The device gave the first accurate readings of a peak flow.

Mini Wrights Peak Flow Meters (circa 1970s)
In the 1970s, Dr. Wright invented a new device that was inexpensive and portable.  It's basically just a "tube with a spring inside and a calibrated scale along the outside.  The puff from the patient under test pushes the spring back.  A pointer registers the furthest point reached.  The meter comes complete with a set of cardboard mouthpieces.  Doctors recon that the instrument could be useful in home treatment. Patient's could monitor their own lung power in a simple and cheap way of determining recovery from lung ailments." (1, page 675)

This instrument was called a "Mini Wright," although ultimately it became known as the peak flow meter. The devices were ultimately manufactured by various companies, and now you can get an array of different types. The first ones were not disposable, although they were soon thereafter manufactured for single patient use only, and the separate cardboard mouthpieces are no longer needed  

Many peak flow meters available today
I remember the "Mini Wright" from when I was an asthma patient back in the late 1970s and throughout the 1980s. Gone are the days of the Mini Wright, replaced by the even cheaper plastic models.

Can you guess how many peak flow meter brands are on the market today?  I couldn't even fathom a guess, although I've had over 20 in my grasp at one point or another.

Reference:
  1. "Hot Air Invention," New Scientist, March 1, 1979, page 675
Further reading and another picture:

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