Design out, Guard, then Warn

Check out this fascinating solution to protecting users from the blade of a table saw.

The way it works is that the saw blade registers electrical contact with human skin and immediately stops. I can’t imagine not having this safety system in place, now that it is available. However, I still have some questions that commenters might want to weigh in on:

1. Unless the system is more redundant than an airplane, it must be able to fail. How do you keep users to remain vigilant when 99.999% of the time there is no penalty for carelessness?

2. To answer my own question, is the fear of a spinning blade strong enough to do that on its own? I know I’m not going to intentionally test the SawStop.

3. Can we use natural fears such as this in other areas of automation?

4. For great insight into human decision making, read this thread on a woodworking site. What would it take to change the mind of this first post-er?

When do we as adult woodworkers take responsibility and understand the dangers of woodworking. Most accidents happen due to not paying attention to what we’re doing. If we stay focused while we’re using power tools, or even hand tools, we eliminate accidents.”

Intuition vs Experience with Roundabouts

Some people might say a traffic circle is obvious. There is only one way to go.. who yields might be more difficult, but at least we are all driving in the same direction.

Not so.

The following two articles come down on the side of experience for the usability of roundabouts.

New Traffic Circle Causes Confusion

Death-crash car launches off the road and into a first floor flat

I am sure the designers believed that if millions of people in London and hundreds of thousands in New Orleans can handle a roundabout, these citizens of a town so small they don’t even bother to mention where it is would do fine.

Facebook privacy issue may be a usability issue?

I am not on the Facebook wagon but I found the controversy over Facebook’s Beacon interesting. Users were inadvertently displaying their online purchases to their friends on Facebook. Facebook claims that users could opt-out of showing this information but many users said it was not obvious. Here are some before and after screenshots [from the NYT blog entry]:

BEFORE [note the very faint X on the right]:

americangangster533.jpg

AFTER [note the word remove after the X]:

epicurious533.jpg

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Why Human Factors is more than providing safety equipment

The new math and physics building is going up outside my window at North Carolina State. I see the workers out there each day, and as the building gets higher they are obviously required to don different safety gear.

The fuzzy picture below shows two workers on the top level (7th floor) and the green highlight is my outline of the full body harness and safety cord the man is wearing. Indeed, it seemed necessary as whatever tool he is using seems to push him off balance with every use (some sort of nail gun?)

workers.jpg

However. Unlike the man behind him, this worker has not attached his safety cord to anything. It merely drags along behind him as he walks around the platform and crawls in and out of the scaffold. In fact, it seems to get in his way when the clasp on the cord catches on the corrugated surface of the platform.

Team Training

Enjoy this video of expert team performance. I note that the post-er says these Marines “cut a lot of corners.” I’d be very interested to know how this differs from what they “should” be doing and what is optimal.

This from comments on the video: “Chief, what are you doing?! That was one jacked up fire mission. Are you trying to get your guys killed in a training mission? Not swabbing the breach or checking the bore while firing slow burning greenbag?! And what are you doing in the way between the trails? Didn’t do FCATS, did you? Don’t trust the quadrant on the gunner’s side?”

Legal Interpretations can be the Bane of Good Human Factors

Verizon wireless interpreted an accessibility requirement to require they trigger a notification when the user dials 911. Verizon chose to do this audibly… exactly what you DON’T want when you’re calling the police during an emergency!

“The tone our customer experienced is our interpretation of Section 255 of the Telecommunications Act calling for a provider of telecommunications service to offer service that is accessible and usable by individuals with disabilities. The tone, indicating that 911 has been dialed, is one of several features designed to make wireless service is accessible and easy to use, especially for those with disabilities. Other features include a voice command key where customers can use their voice to dial by name or number; a voice echo feature so that a person who can’t see can hear the number or letter if sending a text; read back text messages and speech output of signal strength, battery strength, missed calls, voicemail, roaming, time and date.”

Read the full news article here.

Perhaps there was no time for use cases or personas. “Debbie sees 4 masked men breaking into her home. Trapped, she hides in the closet and dials…. oh. Wait, guys. I think we have a problem.”

More medical errors–Operating on the wrong side of the patient’s brain!

There sure seem to be lots of medical errors in the news lately. No mention of human factors:

The most recent case happened Friday when, according to the health department, the chief resident started brain surgery on the wrong side of an 82-year-old patient’s head. The patient was OK, the health department and hospital said.

In February, a different doctor performed neurosurgery on the wrong side of another patient’s head, said Andrea Bagnall-Degos, a health department spokeswoman. That patient was also OK, she said.

But in August, a patient died a few weeks after a third doctor performed brain surgery on the wrong side of his head. That surgery prompted the state to order the hospital to take a series of steps to ensure such a mistake would not happen again, including an independent review of its neurosurgery practices and better verification from doctors of surgery plans.

We can surmise from the short news article that the source of the problem seems to be working memory??

In addition to the fine, the state ordered the hospital to develop a neurosurgery checklist that includes information about the location of the surgery and a patient’s medical history, and to put in place a plan to train staff on the new checklist.

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Patient record mistakes

LOS ANGELES – The recent chatter on a popular social networking site dealt with a problem often overlooked in medicine: mistakes in patients’ medical charts.The twist was the patients were doctors irked to discover gaffes in their own records and sloppy note-taking among their fellow physicians.

Errors can creep into medical charts in various ways. Doctors are often under time pressure and may find themselves taking shortcuts or not fully listening to a patient’s problems. Others rely on their memory to update their patients’ files at the end of the day. Other mistakes can arise from illegible handwriting or coding problems.

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“From the Doctor’s Brain to the Patient’s Vein”

It appears that HFB needs an entire section devoted to medical error. This is not surprising in light of the thousands of Americans who die from preventable errors each year.

The latest comes from Tanzenia where confusion about patient names earned brain surgery for a twisted knee, and knee surgery for a migraine sufferer.

Mr Didas who had been admitted for a knee operation after a motorbike accident is still recovering from the ordeal – he ended up unconscious in intensive care after his head was wrongly operated on. And chronic migraine sufferer Emmanuel Mgaya is likewise, still recovering from his unplanned knee surgery. The blunder was blamed on both patients having the same first name.
But a hospital official, Juma Mkwawa said it was the worst scandal that had happened at Muhimbili hospital and that, “sharing a first name cannot be an excuse”. The two surgeons responsible have been suspended. (BBC)

Before anyone retreats into the comfort of “that wouldn’t happen here,” I suggest a look at the growing literature on similar medication names and their consequences.

It is easy to be the bearer of sad stories and ill tidings. I would rather on a note for a hopeful future. Below are researchers and companies dedicated to identifying and eliminating causes of medical error.

Please add more in the comments section if you know someone working in this important context.

Not blaming the user since 2007!

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