Olfactory Illusions, Dissections, #Vitalsignsmooc #neuromooc

WARNING: Dissection images/videos may not be suitable for younger folks, and/or those with sensitive dispositions. Fair warning, I’m not buying folks new keyboards as they lost their lunch.

Yesterday I went full bore into virtual dissection mode. The first thing I rolled on was the sheep brain dissection in #neuromooc. It was fascinating to see the similarities between the sheep brain and the human brain.  So much so, I must say I’m tempted to go order one as Carolina has them for under $20. Alas, I’m only tempted lol, I’ve got so many irons in the fire, dissecting a sheep brain would end up pretty low on the priority list, and it could sit in a box for ages.

Then again, I’ve explored a human one in the past, albeit it was a short course put on my med students and sadly I’ve forgotten a ton of it. Alas, a few things really did really stick with me,  one item especially. Perhaps it might be better said, stuck on me, and through me. Namely formaldehyde. I could smell it for days after leaving cadaver lab… its like there was this cloud of vapor, and it embedded itself in your being. No amount of cleaning, showering, shaving etc would get rid of it. Even my car smelled like formaldehyde.

And there in lies the rest of the story, but stand by for just a second while I fill in yesterdays background.

My cardiac anatomical knowledge is really shakey, I can go ok, so the left ventrical is here, and oh yes, this is the mitral valve, and left atria, there is the aorta…. but its not bing bing bing automatic. Thus, after the sheep brain dissection, I went searching on youtube for a heart dissection.

Alas, unlike my memories of a human heart where great pains were taken to keep the valves intact… the youtuber sliced right through them… which was not what I was hoping to see. Thus a little more digging, a few more videos, and I ended up here.

All in all, I spent about 3 hours viewing heart dissections from a multitude of places… and it does help. I’m still not 100%, but I’m not crashing and burning if the heart is presented in other than a coronal frame of reference.

However, about 2 hours in, I started smelling formaldehyde. I do not have any formaldehyde here… and then the odor got stronger and stronger, to the point it was like egads. Now the interesting thing was, when I got up to go look outside to see if there was a formaldehyde truck crash or something, the smell went away in a flash. Apparently my brain was playing tricks on me and somehow transporting me back to cadaver lab.

Yep, cadaver lab is intense… I mean the dude whose brain you are holding was alive less than 6 months ago. There are all sorts of crazy emotional stuff that goes on in day 1. I didn’t remember the names… but I sure remembered that the dura was like an armor. I remember the horse tail (cauda equina) comes across as nearly an alien life form, and nothing like what I’d seen in the text books. Alas, despite the intensity of all the human body bits, the formaldyhyde was what played a game with my brain.

A couple links on olfactory illusions:

http://sites.sinauer.com/wolfe3e/chap14/verbolfF.htm
http://www.rachelherz.com/uploads/Odor_Illusions.pdf

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#VitalsignsMOOC Week2 on Cardiac Stuff

This week flew by as the amount of new material was pretty limited. The quiz came out today, and I blew through it in about 5 minutes, getting a couple wrong because I didn’t read them properly. That being said, there is a huge boatload of information to reinforce from last week and a few cool rabbit trails.

I find that my knowledge of heart anatomy is still not at the point of being instantaneous. I’m having to look and think as to what the parts are, and thus more practice is needed. I did come across a most fascinating video from khan, where in they are viewing the heart from a patients perspective looking down into the chest. The interesting thing, albeit obvious point about this view is that it inverts the geometry left/right, in contrast with the anatomical view (coronal) I learned last week. I’m thinking multiple planes of view, both from the patient as well as the anatomical planes may prove beneficial as means of studying anatomy.

Being imaging studies reference the standard anatomical planes, I wonder if the observer (standard anatomical) vs patient reference frames might have played a role in the rapid prototype error discussed in the TED talk entitled how I repaired my own heart.

Hemodynamics has been bugging me to no end… and this graph is less than helpful.

blood_pressure

The use of a linear Y axis completely buries pressure deltas starting with the capillairies and continuing on throughout the cardiac cycle. Alas, digging for a semi log plot of such to bring out the detail seems an exercise in frustration. One interesting bit to consider is the increased frequency in the arterioles, it appears to have doubled, but I’m not sure if that’s an artist error, or if muscle activity from the Tunica Media actually causes this.

Alas, the graph is helpful in one regard, as the first derivative clearly shows that aterioles are the major playing in decreasing pressure such that capillairies dont blow. This is graphical hand waving calculus… I’m not sure how you create a derivative with respect to a sequence of nouns. :)

That being said, I remember a post by @atdiy where she talked about a no beat heart, and some ideas as to why patient quality of life takes a header with a LVAD. Its a most fascinating read. See below for a xray of a no beat heart from healthcollege.edu.pl.

Getting back to a beating heart, I did find the following video of interesting. The author presents pressure variation where the supervior vena cava enters the atria. Its a rabbit trail for sure… but as I expected, there is massive variation in pressure (well massive from the point of view of heart action dicks around with the pressure) but not massive at all relative to the mean arterial pressure at the aorta.

Lastly, I managed to get a bee in my bonnet over what the professor said about mean aterial pressure referring to mean as an average… a moving average perhaps, but not an average of diastolic and systolic pressures. I did find an approximation formula which makes sense at http://www.columbia.edu/~kj3/Chapter3.htm .

Pm = 1/3Ps + 2/3Pd

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@VitalsignsMOOC first week thoughts cardiac stuff

This is proven to be an interesting class so far. Initially I thought it might prove too simplistic and certainly the gaps between clinical practice, medicine, academia, and engineering are huge, but its cool seeing things from another sectors point of view.

A few thoughts:

Plastic heart models are pretty sucky… but then again everything is a compromise when it comes to models, and even more so plastic ones. :) Had I not had experience with pacers, the models would seemingly create a ton of disconnects… but cadaver lab on day 1 would likely be too intimidating, so I guess plastics models are a reasonable compromise. Alas, we do have youtube, and spending an hour viewing an open heart surgery reinforced a ton of material.

http://en.wikipedia.org/wiki/Heart
Human Heart from wikipedia

Wiggers diagrams are incredibly helpful to understand the the cardiac cycle. Alas, there is a lot of information where in google is less than helpful. This is probably due to my rabbit trailing outside the scope of the course…

Things like the dicrotic notch and wave explanations are crazy from an engineering point of view. If measured right at the aorta, one would have the expansion of the aorta as well as the impulse response of the aortic valve and reflected waves returning from other structures.. short of something being highly tuned, my gut feel is some level of ringing would occur in this. On the other hand, if the aorta pressure is measured further away from the heart itself, one would also have reflected fluid momentum playing havoc with the measurement. Is this damped by the elastic nature of the aorta? Are there chemical processes dicking around with the aorta’s modulus of elasticity? What about the degradation of the aorta and valves over time? Alas, these are questions outside the scope of the course.

Heart sounds are tricky and the teaching of them apparently more so. We heard one example, and even after cycling through it a few times, it was still a bugger to pick up the difference.  Alas, youtube was friendly in this case.

This video covers locations in a cool way… marked up tshirts :)

This doctor is incredibly entertaining and he takes complex material and makes it simple, in this case location as well as sounds.

We still have the issue with what on earth are these things supposed to sound like? Alas, a helpful person in the forums shared the following link which presents mp3′s of a number of problems.

http://www.med.umich.edu/lrc/psb/heartsounds/index.htm

ECG’s were briefly touched upon with one bit being that a 12 lead ECG only uses 10 electrodes. In electronics we have conventional current and electron flow… which causes no small amount of confusion as they are reversed.

In medicine it seems everywhere you turn there are legacy terms and some insane need for backwards compatibility that creates endless amounts of circle chasing. Do we really need 3 names for the left atrioventricular valve (bicuspid, mitral). Do we really need to use the term leads when its really a mapping of the electric fields in different planes of reference? And whats with the chart recorder legacy stuff? Such is why I’m not in medicine LOL

A fellow student provided a link to a cool ECG trainer / simulator…

http://www.skillstat.com/tools/ecg-simulator#/-prep

AV Node delay timing in response to exercise is crazy stuff… I remember some of this from pacer discussions, but just as there was ambiguity back then, it appears its still quite vague today. (Tone plays a role such that sometimes it need to roll forwards in othertimes reverse. Granted, this is outside the scope of the course… but seeing the AV node time mention as 0.1 sec brought back memories. Iirc, it was just a tad over that figure, but there are many ways to look at it… AV free running rate is tweaked 20% if memory serves.

Evaluation A multiple choice test was used for purposes of evaluation. The questions were reasonably easy, but did require some level of thought rather than just the parroting back of information. The ultimate test of my knowledge will be if I can draw and annotate a human heart, draw and explain a Wiggons diagram, identify heart sounds, and interpret ECG traces in May 2015. I can do none of the above to 100% correct standards currently, as such requires more practice then a few hours of videos and studies will provide for… but such will be my means of review of the course material to prevent forgetting it.

All in all an interesting class this week. Next week is on blood pressure. I wonder if we will learn the history of the old wives tale of salt bringing about high blood pressure. Its an interesting myth with a tad of truth mixed in just enough to create lots of confusion.

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Learning Physiology in 2014

Over the years I’ve worked on a variety of medical products. Everything from chiropractic gear to blood analyzers to pacemakers. As a result, my knowledge of physiology is scattered all over the place, from jr high school knowledge to somewhat deep, but only in very narrow areas.   As I’d like to have a broader knowledge base, I’ve signed up for a number of MOOC classes across a range of disciplines.  Granted, a MOOC experience will never bring about the same as one might get in a in-person classroom with lab experiences with live, or recently alive bits. On the other hand, I’ve gained a fair bit of knowledge over the years work wise, so it will be interesting to see how the pieces fit together.

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Electricity is no Respector of Man’s Codes

Electricity is no respecter of the NEC or any other regional code for that matter. Electrical codes try to ensure some level of safety but are compromised due to political and economic factors. Codes also change over time, due to bad experiences, lessons learned, as well as changing political / economic factors. Alas, this does not mean they should not be ignored, there is a much good advice within. The danger comes into being when they are viewed as some sort of divine truth.

A common problem in older houses is that most of their electrical outlets are 2 prong thus lacking the ground connection. There are many ways folks try to mitigate this shortcoming, some of which pose electrocution hazards, some of which pose fire hazards, and of course the right way which equates to ripping things to bits and starting over.

The most common approach is a 3 to 2 prong adaptor which is rarely if ever used properly. The little grounding tab is supposed to be connected to ground via an outlets center screw… alas, many boxes are not grounded.

1. Many years ago, BX cable (basically 2 wires surrounded by a spiral metal shell) was commonly used. On a positive note, the spiral metal shell sort of provided a ground path between an outlet box and the main panel. By sort of, it provides a path such that a 3 light outlet tester would likely indicate the outlet was grounded. Alas, under a serious fault condition, the spiral metal sheath might not provide solid enough ground connection to trip the breaker… in some cases, the breaker would not trip, that is until the spiral metal shell turned red hot and melted the insulation off the wires shorting them together and in some cases starting a fire in the wall. (BX has not been sold for many years as it was replaced by AC cable (which looks the almost the same but has a continuous ground specifucally designed for fault currents)

2. The use of a GFCI as a workaround is a legal short cut, and it can serve to mitigate shock hazards. Fire hazards are another story. In some future versions of the NEC, I fully expect this practice to be made illegal, just as the old school means of grounding via a water pipe or single wire to another ground circuit were made illegal. (The NEC does allow one to run a single ground wire back to the main panel, but its vagueness as to wire routing / protection makes for a fire waiting to happen depending upon the installer.)

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On Common Core Math

The idea of common core math is to develop understanding, rather than superficial rote methods in the interest of global competition in STEM and related. The problem with this ideology, is that for the majority of folks out there, getting the right answer quickly rather than really understanding whats going on under the hood makes no sense.

Consider these 4 students and how parents would respond.

1. Little Bobby doesn’t show his work, but gets the right answer. He gets a low grade as when queried, he embraces rote methods with very little understanding of what he is doing.

2 Little Suzy shows her work, makes a mechanical error in writing mid way through the exercises using a unique method,but gets the answer wrong. She gets a higher grade than Bobby as she shows understanding of the process.

3. Little Annie who shows her work and gets the right answer. She gets a higher grade than both Bobby and Suzy, but her approach is purely mechanical. She only uses the methods a given teacher uses over and over, and freaks out when her plug and chug doesn’t work.

4. Little Joey shows his work and gets the right answer. He gets extra points, as he is using a number of methods to get the right answer. He may not always choose the optimum approach, but is demonstrating a deeper level of understanding across a multitude of approaches.

The global competition ideology is the following.
On the job site, little Bobby and Annie will build bridges that if they deviate very far from what he’s seen before will run into trouble. They are likely to be relegated to mundane work. Suzy while potentially error prone if paired up with someone to verify her work is likely to push the envelope. Joey is likely to do well no matter what or where he goes. Global competition suggests we need a lot more Suzy and Joeys than we need Bobbys and Annies… The status quo says Bobby’s and Annies should rule, that is until they are run over by the competition.

The status quo is that 99%+ of society uses rote, and short of a few math nerd teachers, very few outside of some STEM sectors have a rock solid math foundation… This sets the stage for examples like this  to propagate which just adds insult to injury.

 

The above is a terrible example of a decent method. Such is commonly used for doing mental math with large numbers, fractions, and even mixed unit problems like time/date calculations. Mental math while useful to solve equations in mid sentence is a cool and at times a useful thing… but the intuition developed from doing so is where the economic value adder really comes into being. Ie, computers, math models, simulations are all good things, but you must have a pretty good idea of what the answer is before you begin or you will shoot yourself in the foot.

Such is pretty common among the majority of STEM folks I’ve worked with over the years… (and many older tradespeople as well… I’ve known retired carpenters, bricklayers, and machinists who can run math circles around some recent engineering grads who are lost without their computer models.) More often than not, such is the result of having to throw out rote math concepts and rebuilding a foundation from scratch… or in the case of oldsters, because using a slide rule pretty much mandated a solid foundation if they wanted the cool projects rather than the mundane.

I’m not a teacher, but the idea of a firm foundation rather than quick and dirty methods which have to be unlearned later makes sense… Alas doing so goes against the grain of society, many parents who will have fits with low grades for Bobbys who still get the “right” answer, and some suggest that math understanding is too advanced for young kids and that rote should be good enough. I don’t know what the answer is… but hiding ones head in the sand has generally proven not to work out all that well.

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Out of Date Market Research

A fellow sent me some market research today and he was all excited… Cool, its always good when folks do their homework. Alas, the more I read, the more I kept thinking, what planet are these authors on? There was warning sign after warning sign that something was seriously amiss.

Alas, I googled some of the execs quoted in the paper. The key fellow quoted had left his employer in 2007! A bit more googling showed the trending data they were discussing had come and gone in 2004! In hindsight the big warning sign on the whole thing was the lack of a date range for data collection to say nothing of the date of publication. Bottom line, I gave the paper the benefit of a doubt and it cost me.

I fully understand the massive expense of hard core in house market research. I also understand why folks can find it anathama to spend $$$$ for a member ship in a trade association to access current data, or $$$ to buy a single paper. On the other hand, imagine how much this fellow might have spent had he proceeded down a path only to find out he was totally out of sync with his target market 3-6 months later.

In the pre911 days, when I was often in Washington DC, I’d often cruise over to the library of congress just to read market research papers. Often times even the really spendy ones came with a pride factor or something else and they would get deposited there. Alas, such is not the option for most of us, to say nothing of the restriction headaches in today’s security world.

Alas, some market research papers are available, or can be inferred out of data sets available at larger university libraries. Alas, such is often times beyond the scope of a research librarians pervue, but one can get an inkling if a day trip is justified to scope things out in person or not. Albeit such is market dependent… some niche papers have such low demand, the only way the publishers can recoup costs is charging an arm, a leg, and then some.

Alas, one still runs into publishing delays should one be operating in a fast moving market. It would be a sad deal indeed to ride out the low margin tail end of a short cycle market due to delayed upfront data. Granted, most small inventor types run on long tails rather than the leading edge, but its always something to keep in mind.

As such, the pretotype, the minimum viable product, or even vaporware methods of market research can be used to validate ones ideas in light of published data sets. The challenge of course is doing the right type and amount of paper research before entering said stage. Ie, most MVP’s, pretotypes, and even vaporware have an opportunity cost associated with them. There needs to be a reasonable balance between the initial paper based pre-work, and the firm, aim, ready approach or time and money will be wasted.

 

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Commentary / Notes on How do Good Ideas Spread #DTActionLab

Some random ramblings on “How Do Good Ideas Spread” This is more along the line of notes and insights I picked up from the article for my own purposes rather than a formal blog post. Excuse the scatterbrainess.

**************** From Twitter ***************

Good article for #DTActionLab #VirtualLibrary: “How Do Good Ideas Spread?”in @NewYorker http://goo.gl/tBWkxf 

********************************************

Wowzers… I wish I had read this years ago. I learned early on that if you have a new product which requires significant customer education / rethinking and things become a nightmare fast. One can spout the benefits of a product, process, or idea left and right, like Lister’s use of carbolic acid sprays and aseptic procedures resulting in significant decreases in mortality. On the other hand, being said sprays also left the surgeon’s hands raw, to say nothing of a near total mindset reset in related domains, no wonder the adoption period was so lengthy.

The 7 points of contact bit was interesting… such could lead one to believe that the use of ones existing sales and distribution force could easily bring a new product to market fast.  One barrier I’ve noticed with this as concerns the retraining/rethinking type product models is it takes the sales force from a consulting / procurement resource to one of an peer/educator…. which from a personal dynamics pov is tricky to navigate.

Over the years, many entities in the EE realm have tried to work around this with traveling field / apps engineers. Short of the late Bob Pease or Walt Jung (massive personal brand individuals in the analog realm) , the frequency / relationship building using field/apps guys takes an incredibly long period of time. In my experience, such relationship/time building far too often exceeds the duration of said field /apps engineers employment with a given firm. If one then adds in the paranoia of a Men’s Wearhouse/George Zimmer deal where one guy pretty much becomes the brand, its easy to understand the rarity of corps encouraging the development of massive personal brand individuals.

The birthing center nurse examples were also interesting.

The use of “Please Do X” and “You must do X” almost always fail, as they dont get to the big deal thing that changes behavior, ie getting folks hearts and minds on board. Such is where the relationship/time building things end up being the most effective, but sadly are also the most costly and time intensive.

All of the above being said, social media has the potential to be a game changer… or at least I think it does as the relationship building time can be substantially compressed. It would need to be done correctly, and with that comes risk. Ie, the use of invisible individual(s) with generic personality pronouncing canned PR bits makes sense to avoid the George Zimmer Men’s Wearhouse deal. Otoh, it takes the time compression advantage of social media and throws it right out the window.  No doubt this will take some time to sort out.

My view at looking at this thinks is in the domain of the business to business marketing of ideas, products, and process as it parallels the sale of ideas to the medical profession.

 

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Heathkit Exhaust Gas Analyzer Model CI-1080

I saw one of these pop up on ebay and then seeing it sell for over $300 about knocked me on the floor. I can understand a sentimentality for a kit a relative built, or perhaps someone used in their youth… but as far as functionality, egads.

The Heathkit unit works by detecting differences in the thermal conductivity of the exhaust gas relative to air. Its a much simpler and less expensive method than infrared spectroscopy and it should give a reasonable ball park for values less than stoke… provided you sample the exhaust gas stream AHEAD of the catalytic convertor. I use the term should, as the fuels back in the day when this unit was developed are quite a bit different than today. I dont know if this will or will not affect the accuracy.

That being said, the unit raised my curiousity a lot, so I had to dig into the details a bit. It uses a pair of matched thermistors in a bridge configuration, with one in a “air” reference environment, and one in the exhaust stream. The thermistor model is matched pair of Fenwall G126B, a 2K thermistor at 25C with a 200ohm value at 150C. Sadly this part is not a catalog item by any means, but Honeywell (who bought out Fenwall) still offers the 126 series… no idea on minimum order quantities.

You can see a schematic and manual for the Heathkit CI-1080 at the Wedge Labs.

Y

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Open Spirometry

A spirometer is a medical device used to measure pulmonary function. In its most basic form, it measures air flow, and either directly or via integration, air volume. Most commercial units rely on some form of a mechanical turbine as a sensor, but there are a number of ways one might measure said flow velocities.

Spirometers are pretty high priced units $1000 plus… Considering I can buy a microprocessor based wind measurement device (which is not unlike a spirometer) for under $15 including shipping, there is a lot of money on the table. Granted, a spiro is more sensitive… but rather than the delrin bearings in a wind device, a couple jewel bearings do not equate to a 20X multiplier in msrp. The worst part is that high prices preclude the use of sprios and other medical devices in world markets where $1000 is just too expensive. At some point, it will be solved once an outfit decides to canibalize the world market for spirometers… but that could take some time if it ever happens. One can look to China, and they have a spirometer for under $300, but such is a far cry from the $30-50 range.

I’m guess part of the problem is Chinese and other medical device manufacturers are likely to be thwarted left and right by govt regulators to say nothing of intellectual property law gamesmanship. Alas, sooner or later it is likely to happen as markets will force the issue, but it is a matter of when. As a buddy who grew up in China used to tell me the mantra of manufacturing plants he knew about… if junk makes money, we will make it. If quality makes money, we will make it… if we can’t make a quick buck with ease, we wont touch it. Ultimately it comes down to when someone can make decent money with sub $50 units.

Some folks over at UW-Madison started openspirometry some years back to address the insane price of commercial devices leading to a lack of diagnostics in less economically advantage cultures. It looked to be a great student project… alas, it sort of died on the vine after a few years, so I checked into it.

Image

 

Hmmm… I did a little poking around to see where things are in the commerical world. I found this patent on injection molding turbines to make disposable units pretty fascinating. A little more digging and wowzers, 200 disposable turbine and mouth piece assemblies for just a tad under $300. Or in plain and simple terms, labor and materials to make these mouth piece turbine assemblies is likely in the $0.25 – $0.50 range. If such were to be paired with wind instrument electronics (photo tach, micro processor, and LCD) the problem is really close to being technically solved. Alas, its unlikely that MIR will be really pleased with someone buying hundreds of thousands of turbines w/o their $1000 support electronics. Likewise until the patent runs out, injection molding a 1 piece mouth piece turbine assembly is pretty hard to work around from an intellectual property point of view.

It would be easy to open source the phototach and user interface… but the problem remains with the basic sensor. I’l have to think on this.

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