The physics of maiming a child

Dear driver,

When you backed out of a driveway and did not even see how I swerved around behind your car to avoid T-boning you, how dare you have the temerity to tell me you were careful!  I was 7 feet tall, dressed in bright yellow and traveling at no more than 10 km/h.  Perhaps a simple lesson in physics will help you and your fellow “driveway backers” to realise how dangerous you are and to adopt safer driving practices.

In the diagram you can see a car backing out of a driveway.  Typically when you are at the edge of your property and have a fence (see photo below) blocking your view of the footpath you are able to see about 1.7 metres along the footpath.  Let us imagine that there is a child on a trike riding at 5 km/h just out of your line of sight.  How long  does it take them to travel that 1.67 metres?  The physics is quite easy.

Car backing out of a driveway.  Illustration of how little of the footpath can be observed.

Car backing out of a driveway. Illustration of how little of the footpath can be observed.

Velocity = distance/time, therefore time = distance/Velocity.

5 km/h is 5000 metres in 60 x 60 seconds, ie about 1.4 m/s.  Putting this in the formula above means that it takes about 1.2 seconds for the child to travel that 1.67 metres.

Now consider this. According to design guidelines for safe bicycle use 2.5 seconds must be allowed for someone to observe the danger, react, apply brakes and stop.  In other words, if you covered the distance from your driveway to the middle of the footpath, about 1 metre, in under 1.2 seconds you will almost certainly hit the child.  That is a speed of just 3 km/h!!!!!

Now consider who else is on the footpath, all legally:

  • Pedestrians 5 km/h
  • Joggers 5- 15 km/h
  • Kids on skateboards or scooters 10 km/h
  • Child on bicycle with small wheels, 10 km/h
  • Mobility scooter, 5-10 km/h
  • Me on my Trikke, 10 km/h
  • Postie on a bike 5-10 km/h.

For those going 10 km/h your speed needs to be just over 1.5 km/h to hit someone!

So, before you do some damage here is what you can do:

  • Never back out of a driveway unless you really really must.  If you think you must because of the design of your driveway, change the design!
  • Cut back those hedges, remove some of that fence so that you can see further.
  • Always always always stop at the end of your driveway (BEFORE THE FOOTPATH) and toot a horn.  Then proceed very very slowly.

By the way, you are legally obliged to give way:

 Land Transport (Road User) Rule 2004

4.4 Giving way when entering or exiting driveway

(1)
A driver entering or exiting a driveway must give way to a road user on a footpath, cycle path, or shared path (as described by clause 11.1A(1)).

Thank you for considering the physics of maiming a child, may you never find your self in such a terrible situation.

Regards,

Dr John Pickering

A typical driveway with almost non-existant visibility

A typical driveway with almost non-existent visibility

Why you should care about Oregon

Reblogged from Stray Thoughts:

Click to visit the original post

For those of you who haven't heard, there is big news out of Oregon.

Oregon is a fascinating place right now for those interested in health policy, and here's why: What amounts to a giant experiment on the expansion of Medicaid is taking place there as we speak. In 2008, Oregon had a limited amount of funding to expand Medicaid. There were far more people who wanted to join the Medicaid pool than could be funded.

Read more… 1,343 more words

I love the way this med student writes. This is a fascinating account of an "accidental" randomised controlled trial of government spending on health (Medicaid in the US).

Two new Health Research Council grants worth crowing about

This week’s announcement by the HRC of Feasibility Study and Emerging Researcher grants have many great projects.  Two in particular are worth crowing about (because they have some relationship to kidneys and they involve two excellent people).  I have put summaries in their own words below, but first my comments.

Dr Palmer (Department of Medicine, University of Otago Christchurch), who has appeared on this blog site before, conducts what in the trade are called “meta-analyses” and “systematic reviews.”  Simply put, these are methods to extract the best possible evidence from all the studies that have been done for the effectiveness of a treatment.  Just as one person may toss a coin 4 times in a row and get 4 heads, so too can any one trial give a mistaken impression that a treatment is efficacious (or not) when it really isn’t (or is).  By pooling together many treatments Suetonia provides the very best quality evidence available.  Given that Chronic Kidney Disease affects a large and growing proportion of us, knowing which treatments have the best outcomes is of national significance, not merely to our health but also to the national budget.  A particular problem is that after a trial it can be many many years until meaningful health outcomes are know (e.g. if the treatment delays dialysis need or reduces mortality).  Suetonia’s study will assess the effectiveness of surrogate endpoints for clinical trials.  Surrogate endpoints, such as plasma creatinine which I’ve discussed many time in this blog, are physiologically related to the functioning of an organ or to a disease state as well as statistically associated with future hard outcomes.  However, their use in trials is limited by how well they are associated and how they are used.  I look forward to finding out what Suetonia discovers.

Mrs Rachael Parke (Auckland DHB) is an experienced nurse undertaking a PhD. Ensuring patients have adequate fluids on board is particularly crucial to the kidneys and other organs. Obviously with surgery any blood loss needs to be compensated for. However, there are also physiological changes in where fluid is distributed throughout the body.  Cardiopulmonary bypass, used in cardiac surgery, is a particular risk factor for Acute Kidney Injury. In the past the practice has been to give large amounts of fluid in order to ensure adequate fluid is given.  However, recent research has shown that too much fluid can have a negative impact (increased mortality).  A more restrictive fluid regime may have very meaningful outcomes.  Rachael is investigating, in a randomised controlled trial, if restricting fluid improves outcomes.  The outcome she is most interested in is how long patients stay in the hospital.  This is a very practical outcome for both patient and budget.  I am particularly pleased that this study is nurse-led.  Nurses play an incredibly important role in research as well as patient management.

In their own words:

Dr Suetonia Palmer: Making better clinical decisions to prevent kidney disease

More than ten percent of adults will develop chronic kidney disease. The effectiveness of many treatments used to improve outcomes in kidney disease is tested against surrogate (indirect) markers of health (e.g., cholesterol levels or blood pressure).

Unexpectedly, subsequent systematic analysis has identified little evidence to show that treatment strategies based on these surrogate markers translate to improved health for patients. Serum creatinine and proteinuria levels are commonly-used markers of kidney function to guide treatment.

The research involves using systematic review methods to summarise the quality of evidence for using proteinuria and serum creatinine as markers of treatment effectiveness in clinical trials. It will be determined whether using these markers to guide clinical care improves patient health or, conversely, leads to treatment-related harm or excessive use of ineffective medication.

These summaries will help clinicians and patients make better shared decisions about which therapeutic strategies actually improve clinical outcomes in kidney disease.

Mrs Rachel Parke: Fluid therapy after cardiac surgery – A feasibility study

Following cardiac surgery, patients receive large amounts of fluid in the intensive care unit. This may cause problems with wound healing and delay hospital discharge. A planned randomised controlled trial of a restrictive fluid regime as compared to a more liberal approach utilising advance hemodynamic monitoring, aims to reduce the amount of fluid patients receive and reduce hospital length of stay. This feasibility study aims to determine whether this nurse-led protocol is practicable and feasible and will help answer the research question. This study is simple and inexpensive and if it demonstrates a decreased length of hospital stay then this will represent a significant benefit for both individual patients and the health system.

University of Otago Papanui turns 800

Day one was ground breaking – 23 Feb 2011, the day after the big Christchurch earthquake.  Today is day 800 of what I lovingly refer to as the Papanui campus of University of Otago Christchurch.  For my children it’s just the office out the front of the house where their father works.  For me, it used to be my workshop & study.  Once upon a time it was computer and telephone free!  That all changed at midday on 22 February 2011 when I and my colleagues were unceremoniously thrown out of the University of Otago Christchurch building (you know the big building at the front of Christchurch hospital with the glass facade with the words “Research Saves Lives” written across it).  My ICU, ED and other medico colleagues went to work immediately, while the rest of us watched the first of the injured arrive at the hospital on the back of utes and sitting in the boots of cars. I hung around until I was sure my students and staff could all get home.  After an hour or so I walked home – first across Hagley park with hundreds of others exiting the city.  I chatted with a woman who got out of Ballantynes and another who escaped the carnage in Cashel Street.  A house not far from my own had partially collapsed – I went on to the property and called out to see if anyone was there.  I got hold of a neighbour who told me that the people who live there both work somewhere in town.  I prayed that they would be OK as they were in for a shock when they returned home.  Eventually I get home.  My family, including the dog, were not there – they had gone looking for me.  All the while the ground kept shaking.  My family returned and we rejoiced in each other’s presence.

My OfficeThe next day I opened my office thinking I may have to work at home for a few days.  My PhD student Dr Maryam Nejat was in touch.  She got home OK, but she was at a loss what to do about her thesis.  It was on her computer at work.  She’d been due to submit it within a month.  Fortunately, I had a laptop at home with a reasonably recent draft.  Maryam came around and we got to work, the first meeting at the Papanui campus.

The Papanui Campus

The Papanui Campus

When the quake hit I’d been in the middle of submitting an article to a journal for consideration for publication.  This too had to be retrieved and resubmitted somehow.  My colleagues involved in lab research suddenly had their facilities unavailable.  They were very concerned about the welfare of the animals.  My somewhat minimal role as group manager took on a new dimension.  Fortunately, those I work with were so very competent.  We discovered the animals had taken great priority and people were in the building feeding and caring for them all the while nobody else went inside.

As we watched the news, prayed for rescues, and held our breath every time the earth moved my thoughts turned to what else I could do.  I was fortunate to live in an area relatively unharmed, apart from the one house I mentioned.  The little liquefaction in the road around the corner had quickly been moved off the footpaths into the gutters and I’d hopped on the roof the neighbour’s house to remove chimney bricks threatening to fall on those below.  No medical skills, no search and rescue skills, no great shakes with a shovel (besides, my family didn’t want me out of sight for a while), I did what I could and went into work, 5 metres from the front door.  After all, Acute Kidney Injury is a great risk in crush victims and while I couldn’t help the people in the Christchurch quake, maybe I’ll do something for other quake victims in the future.

Messages started to come through from the Dean. The building had been yellow stickered for “remedial work”, but it looked like we would only be out of the building for about 4-8 weeks.  In the meantime, we were allowed to enter the building to retrieve essential items (computer!).

After 7 weeks (mid April) we were told occupancy of our offices and labs may not be till July. So I beefed up my broadband allowance.  Then we were told September (2011 remember!).  After that predictions no longer came.  The first staff went back into the building in November 2012, 21 months after the quake.  Nearly all academics (I may be the last left working elsewhere?) are back in the building now, the labs are open, the students are at lectures, the library is moving back in next week, and the Dean’s office should be back in about a month.

So, day 800 and lots to celebrate at the Papanui Campus:  Two PhD theses, 15 journal articles submitted and accepted, 1 book chapter, an ED & ICU study completed, another ICU study data collected, a lab study managed to completion in temporary location, new collaborations with colleagues in Germany, USA, Canada and Auckland, and a couple of online conferences.  An additional bonus has been the joy of working from home and seeing my family throughout the day (my children are Home educated).  Not so thrilling is the dog coming and nudging me when he wants some attention. Scariest moment was the large “after shock” in June 2011 where I held on to the monitor, ducked my head under the desk, and my group director on Skype from Sydney watched my printer fly off a filing cabinet behind me.  Perhaps the most difficult thing for a scientist working alone is the sense of isolation.  Email and Skype only partially ameliorate that.  I also make regular trips into town to visit colleagues and drink coffee.  Of the writing of blogs there is no end, but I have found participating in a couple of online blogging communities has kept me from having too narrow a focus.  How many more days there are for the Papanui Campus I do not know.  Little did I know when I built this Versatile sleepout 12 years ago that it would become a small outpost of Otago University. I don’t expect it will make the official history of the university, but it is now indelibly part of my personal history and I am very grateful that I have been able to work here.

Papanui campus in action. Left to right: Myself, Dr Azrina Md Ralib, Prof Zoltan Endre

Papanui campus in action. Left to right: Myself, Dr Azrina Md Ralib, Prof Zoltan Endre

NZ Scientists already well engaged in the National Science Challenges

Sorry to post twice in a day, but this is worth a look.  In the April Cabinet paper (here as a pdf) is an interesting graph which shows that 72.5% of current Vote Science and Innovation contestable and CRI core funding already goes to the newly announced National Science Challenges.  By my calcs the additional funding will push this to 78% assuming no increase in the “Research outside the Challenges” slice of the pie.  Have the challenges, therefore, merely reflected what is going on already in the science community?  One of the unanswered questions is “Which challenges will get the most funding from the new money?”  The graph shows the status quo.

The tao of science missed by National Science Challenges

The challenges are out. The committee has spoken. And now the critics respond.  Word on science street and in the media goes a bit like this:

Brilliant $73M more for science in New Zealand.  Well done Steven Joyce and the National Party.

Lacking in lustre.  These challenges are all a bit predictable. [eg Prof Hendy here]

Damn.  My research does not fit any of the challenges. [eg Dr Wiles here]

I sympathise with each of these opinions.  The National party has set a goal of 0.8 percent of GDP for science.  This is to be applauded. They have chosen a path of narrowing the scope of science to ensure it meets their own ideology of “government’s job is to grow the economy”.  This is reflected in the challenges and the language around them.  For example the challenge “High value nutrition: research to develop high value foods with health benefits” in the Peak Report document states:

There is enormous capacity to leverage both our primary industry and medical research to discover, validate and develop nutritional products with proven health benefits of significant market potential.

Some scientists seem to think that economic goals some how “devalue” science.  I am rather more pragmatic in suggesting that an economic return is an inevitable result of doing science.  The difficulty, though, is that any attempt to pick winners – and that is what the National Science Challenges does, fails to recognise that science at its best is not shackled but free to explore and expand.  Science by its very nature is at a frontier and a journey into lands unknown.  A pathway cannot be chosen for it and any attempt to do so will as often as not go straight past the pot of gold.

The National Science Challenges have been chosen by committee – there are “winners” and “losers” and the result is necessarily bland.  This is inevitable when science is done by committee.  Great science comes from great scientists who are driven to great discoveries.  It is driven by leadership, and leadership never comes from a committee.  On Morning Report this morning the interviewer and Prof Hendy both mentioned the US Space Program as an example of a truly exciting and great science challenge.  That challenge came from a great leader, President Kennedy, and while driven politically, the political goal was the same as the science vision.  Sadly, once the political goal had been reached the politicians turned elsewhere and the science community was left holding on to a few rocks and a vision shattered.

From my perspective what is needed for science in this country even more than challenges is vision and visionaries.  We need to fund scientists first and projects second.  Sadly, we have that priority completely around the wrong way.  Dr Wiles who ironically was one of the faces of science on the television campaign encouraging public submissions on the challenges is disappointed that her area of research, infectious diseases, is not acknowledged in a challenge.  I am disappointed that enthusiastic talented scientists like Dr Wiles are not directly receiving 3, 5, 10 year’s of salary and research cost support from this new money to pursue their vision. It’s not so much the topic of research as the researcher that counts.  I have a challenge for the New Zealand government.  And that is for their science policy to be evidence based (see Grant Jacobs’ blog post).  Part of that puzzle is whether it is best to fund researchers or to fund projects. This is why I say the Challenges have missed the tao of science – they are not in harmony with the way science is really done.  Let us run a trial.  Randomly select ten scientists and fund their salaries and $100K a year and let them pursue whatever they want.  Compare this to the results of randomly selected National Science Challenge funded projects with the same number of scientists involved.  The title of the trial could be “Is picking winners better than letting winners pick?

The Face of Kidney Attack Part III

He didn’t die, quite.  But later thought he may well of.  Steve Gurney’s episode of Acute Kidney Injury (see Part II) didn’t finish him after he was discharged from his third hospital (one each in Malaysia, Singapore and New Zealand) – 4 weeks after the event. While media outlets clamoured to hear the story of this amazing athlete’s brush with death, he had a $92,000 medical bill and was so weak he could barely walk.  He couldn’t return to his own home because it was on a hill and he couldn’t make it up the steep track.

Steve did all the right things.  He began exercising by walking to the letterbox and gradually increased it from there.  He lived on fruit, vegetables, nuts, legumes and meat – nothing pre-processed.  While his body began to be restored, it was the mental anguish – so often hidden from others – that really shook him up.  This from his book “Lucky Legs”:

“I’d gone from top dog in my sport to lowly turtle.  My aim to compete as a mountain biker in the Olympics had disappeared down a mud puddle.  I’d lost 15 kilograms, mostly muscle, there was a possibility of permanent kidney damage and my career as a pro athlete was in question.  My fuzzy mind reasoned that the ‘mat of my expertise’ had been jerked from under my feet now that I had been robbed of my fitness, too.  It was like the bottom had fallen out of my world and I was falling, out of control, with nothing to ground me.  ….The depression went on for six months … death seemed like a realistic solution  … But there was a tiny spark that said, ‘Don’t jump. … hang in there … like a long endurance race …”

Steve’s story of recovery is one of endurance and it is one of reaching out for help.  Some of the help Steve got was from practices which scientifically speaking don’t have a leg to stand on, yet the process of reaching out and talking with people concerned and willing to help was, and is to anyone in similar situations, so very important.  Steve didn’t go for homeopathy, but I’ve been told be someone who acknowledges it is a load of nonsense that they think it valuable to have in the community because of the power of the placebo affect.  She may well be right (needs a study).

Steve wins again

Steve wins again

The story continues and is one of anguish and triumph.  The two time winner of the Coast to Coast returned to it three years after his brush with death and won again, and then won another six years in a row.  Steve’s experiences had strengthened him mentally and focussed him on the things that mattered most to him.  As he said, “Contracting leptospirosis … was a good thing.”

There is an ancient Hebrew concept of health called “shalom.”  Often translated simply as “peace” it is actually much broader than that.  Unlike the common idea of health being merely an absence of illness, it encompasses the notion of being in right relationships – spiritually, physically, environmentally, and communally.  Those of us working in medical science do well to be reminded of shalom.