tag:theconversation.com,2011:/us/topics/ecg-1214/articlesECG – The Conversation2024-02-26T14:29:00Ztag:theconversation.com,2011:article/2241972024-02-26T14:29:00Z2024-02-26T14:29:00ZA blow to the heart can kill you – or bring you back to life<figure><img src="https://images.theconversation.com/files/577875/original/file-20240226-24-sifrhx.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C4428%2C2941&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/luo-yang-china-april-22-2011-672272734">xian-photos/Shutterstock</a></span></figcaption></figure><p>I first became aware of the notion of the “touch of death” as a teenager – after watching Uma Thurman as the Bride finally kill Bill using the <a href="https://www.youtube.com/watch?v=KfpqRKNzgIc">five-point-palm exploding-heart technique</a>. More recently, news has broken that the death of political prisoner, Alexei Navalny, may have been a result of a single, forceful <a href="https://www.thetimes.co.uk/article/alexei-navalny-killed-punch-death-cause-russia-putin-x86g6jcdx">blow to the chest</a> – apparently a trademark of the KGB. </p>
<p>Fact or fiction? These propositions are at best grossly speculative. But it is indeed possible for the heart to stop following trauma, through disruption at a particular point in its cycle of <a href="https://www.khanacademy.org/science/health-and-medicine/circulatory-system/circulatory-system-introduction/v/lub-dub">“lub-dub” beating</a>. This phenomenon is named <a href="https://link.springer.com/article/10.1007/s40279-023-01873-6">commotio cordis</a> – literally “agitation of the heart”.</p>
<p>The body region of interest here is the <a href="https://www.kenhub.com/en/library/anatomy/precordium">precordium</a>, the area of the chest wall lying directly above the heart. This region is found in most of us on our left-hand side, with the heart’s apex pointing towards the left nipple. Within this area, you can feel for the heartbeat. This is best when it is beating forcefully after exercise or exertion, as many of us will have experienced.</p>
<p>The precordium is a shield, made of the ribs and their muscles, which inflate and deflate our chest. Further swaddling is provided by the pericardium, a sac of membranes interposed with cuffs of shock-absorbing fat and fluid. </p>
<figure class="align-center ">
<img alt="Alexey Navalny" src="https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/577882/original/file-20240226-24-i519pi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Some reports claimed that Navalny had been killed with a single blow to the heart.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/alexey-navalny-demonstration-russia-russian-march-1651844506">Rosfoto.ru/Shutterstock</a></span>
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<p>You can see that the heart is well protected, yet may still be vulnerable. In reality, commotio cordis is more frequently seen in young athletes, as a result of blunt impact trauma by a hard object such as a baseball or hockey puck. Most recently, the NFL player <a href="https://www.youtube.com/watch?v=S_JqJvjkC5o">Damar Hamlin</a> sustained commotio cordis as a result of a heavy tackle but was luckily resuscitated. </p>
<p>The good news for these athletes is that the window of opportunity for impact to trigger commotio cordis is small. First, the impact has to occur specifically to the precordium. Second, it must be of sufficient energy to deliver enough mechanical force to the heart’s pumping muscle. </p>
<p>Third, it must occur in a very specific section of the heart’s electrical rhythm. On a trace of the cardiac cycle – an electrocardiogram, or ECG – this is the region known as the T wave upstroke. This accounts for only about 1% of the whole cardiac cycle, making the likelihood (according to timing) around a one-in-a-hundred chance.</p>
<p>This makes commotio cordis a rarity, but nonetheless significant. The disruption of the cardiac cycle here can lead to a severe, potentially lethal rhythmic disorder. This is known as <a href="https://www.mayoclinic.org/diseases-conditions/ventricular-fibrillation/symptoms-causes/syc-20364523">ventricular fibrillation</a>. Medical teams must act quickly, using chest compressions, adrenaline and resuscitation with a defibrillator to restore a normal cardiac rhythm. </p>
<h2>How to save a life</h2>
<p>As much as a blow can be implicated in stopping a heart dead in its tracks, there are situations where it may be capable of doing the opposite. </p>
<p>Historically, part of the algorithm for treating a patient in cardiac arrest was to first strike the precordium once using the base of a clenched fist. This is called a <a href="https://onlinelibrary.wiley.com/doi/10.1111/j.1540-8159.2007.00642.x">precordial thump</a>, and has worked its way into resuscitation scenes in medical series like Grey’s Anatomy, though mostly for dramatic effect. In some cases, it has been found to restore normal heart rhythm, and therefore function. </p>
<p>The speculative reason as to why a precordial thump might work is the conversion of the mechanical force into <a href="https://pubmed.ncbi.nlm.nih.gov/20825861/">tiny electrical currents</a> that reset the heart’s rhythm back to normal. However, it is this same mechanism that is also likely to be responsible for commotio cordis. This runs the risk of making the problem much worse.</p>
<p>The precordial thump has therefore fallen out of grace. Some studies have found <a href="https://www.resus.org.uk/about-us/news-and-events/tv-and-film-thump-not-effective-alternative-cpr-researchers-university">no benefit</a> for its use at all. As such, it has been removed from <a href="https://www.resus.org.uk/sites/default/files/2024-01/Adult%20Advanced%20Life%20Support%20Algorithm%202021%20Aug%202023.pdf">advanced life support guidelines</a> in the UK. </p>
<p>So, despite being shielded by many layers of bone, muscle and membrane, the heart is still a delicate entity. You could be trained to strike the precordium at the correct site and with enough force. But being able to hit the heart at the precise time needed to trigger commotio cordis makes the reality of the death touch unlikely. </p>
<p>Perhaps being one of the 0.00008% of the population who have <a href="https://www.hopkinsmedicine.org/health/conditions-and-diseases/dextrocardia">dextrocardia</a> – a condition where the heart is secretly located on the right side of the body – might be in your favour.</p><img src="https://counter.theconversation.com/content/224197/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dan Baumgardt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some claim that Alexei Navalny was killed by a single blow to the heart. But is this feasible?Dan Baumgardt, Senior Lecturer, School of Physiology, Pharmacology and Neuroscience, University of BristolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1435932020-07-29T04:06:49Z2020-07-29T04:06:49ZWhy is the government restricting Medicare funds for ECGs when expert advice says exactly the opposite?<figure><img src="https://images.theconversation.com/files/350087/original/file-20200729-19-3zeqde.jpg?ixlib=rb-1.1.0&rect=0%2C147%2C4108%2C2545&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>From August 1, if the federal government has its way, Medicare will <a href="https://www.abc.net.au/news/2020-07-28/medicare-changes-to-heart-procedures-could-hamper-patient-care/12496894">stop paying</a> for GPs to interpret common heart tests called electrocardiograms, or ECGs.</p>
<p>Health Minister Greg Hunt says the decision is based on safety advice from a top-level medical expert panel convened by the government to review Medicare rebates. But a closer look at the advice reveals the panel suggested precisely the opposite.</p>
<p>And by treating ECG interpretation as a specialised task rather than an everyday part of a GP’s toolkit, the change risks making it harder and more expensive for patients to access these simple but potentially life-saving tests.</p>
<h2>What are ECGs?</h2>
<p><a href="https://www.healthdirect.gov.au/electrocardiogram-ecg">ECGs</a> are tracings of the heart’s electrical activity. If you’ve watched a medical drama on TV and seen a flat line on a screen bounce back to a healthy wobbly line as a patient is rescued from cardiac arrest, you’ve seen an example of an ECG – it’s that wobbly line.</p>
<p>In fact, ECGs in real life typically consist of 12 different wobbly lines (a so-called “12-lead ECG”), as the heart’s electrical activity is measured from different directions. If you’ve had one yourself, you may remember sticky patches being placed on your skin, and a tangle of wires connecting these patches to a special machine that prints out the ECG trace.</p>
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Read more:
<a href="https://theconversation.com/your-apple-watch-can-now-record-your-ecg-but-what-does-that-mean-and-can-you-trust-it-103430">Your Apple Watch can now record your ECG – but what does that mean and can you trust it?</a>
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<p>These tests are a common tool for many doctors, including GPs. All medical students are expected to learn to interpret an ECG – it is not a test reserved for cardiologists.</p>
<p>There are all sorts of situations in which a GP may need to use and interpret an ECG. One obvious example is when a patient is suffering chest pain that could be due to a <a href="https://theconversation.com/how-australians-die-cause-1-heart-diseases-and-stroke-57423">heart attack or angina</a>. Others include assessing unusual heart rhythms, such as <a href="https://theconversation.com/getting-to-the-heart-of-the-matter-on-stroke-7180">atrial fibrillation</a>, which is a common and important risk factor for stroke that <a href="https://www1.racgp.org.au/ajgp/2019/october/atrial-fibrillation">GPs are encouraged to detect and treat</a>.</p>
<p>ECGs are so fundamental that Australian general practices <a href="https://www.racgp.org.au/running-a-practice/practice-standards/standards-5th-edition/standards-for-general-practices-5th-ed">are required to demonstrate “timely access” to an ECG machine</a> as part of their accreditation.</p>
<h2>What is the government proposing?</h2>
<p>Medicare has for many years <a href="http://www9.health.gov.au/mbs/fullDisplay.cfm?type=item&q=11700&qt=item&criteria=11700">funded the tracing and reporting of ECGs</a> in general practice. The government <a href="https://www1.racgp.org.au/newsgp/professional/gps-call-out-ridiculous-changes-to-cardiac-imaging">is now proposing to remove funding</a> of the reporting of ECGs from GPs. Funding for interpretation or reporting of ECGs will be restricted to specialists.</p>
<p>Under the new plan, public funding for ECGs in general practice will be restricted to producing (rather than interpreting) the trace. This is a technical task rather than a medical one, and many GPs, who rightly feel qualified to interpret ECGs, <a href="https://www1.racgp.org.au/newsgp/professional/gps-call-out-ridiculous-changes-to-cardiac-imaging">find this insulting</a>.</p>
<p>More importantly, this loss of funding may harm patients. As shadow health minister Chris Bowen <a href="https://www.abc.net.au/news/2020-07-28/medicare-changes-to-heart-procedures-could-hamper-patient-care/12496894">has explained</a>, an increase in out-of-pocket costs to patients, or a reduction in funding to general practice, may limit availability of this important test to people who need it. There is <a href="https://theconversation.com/six-dollar-co-payment-to-see-a-doctor-a-gps-view-21915">good evidence</a> out-of-pocket costs limit access to health care.</p>
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<em>
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Read more:
<a href="https://theconversation.com/six-dollar-co-payment-to-see-a-doctor-a-gps-view-21915">Six dollar co-payment to see a doctor: a GP's view </a>
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<p>While traces can be forwarded to a cardiologist for interpretation, this too may involve costs, and may be difficult in rural and remote areas.</p>
<h2>The health minister’s explanation doesn’t stack up</h2>
<p>Pressed to justify these proposals, health minister Greg Hunt this week <a href="https://www.theguardian.com/australia-news/live/2020/jul/28/coronavirus-australia-victoria-aged-care-outbreak-melbourne-sydney-nsw-qld-andrews-berejiklian-morrison-latest-updates?CMP=share_btn_tw&page=with:block-5f1f4d798f080665365e6caf#block-5f1f4d798f080665365e6caf">told the ABC</a>:</p>
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<p>This came from a medical expert panel. It came from what’s known as the Medicare taskforce, led by Prof Bruce Robinson. It’s the highest clinical advice and it was based on safety.</p>
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<p>A Department of Health spokesperson <a href="https://www.abc.net.au/news/2020-07-28/medicare-changes-to-heart-procedures-could-hamper-patient-care/12496894">offered a similar line</a> to the ABC in a news article this week.</p>
<p>The taskforce (formally called the <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/MBSReviewTaskforce">Medicare Benefits Schedule Review Taskforce</a>) has been working to reform the Medicare schedule – that is, the list of medical services funded by Medicare. This is a fine initiative, which brings evidence and expertise to the task of modernising Medicare. Appropriately, it enjoys the bipartisan support of our major parties. It is laudable when the government follows such independent expert advice.</p>
<p>The problem here is that, contrary to Hunt’s claim, the MBS Review Taskforce did not recommend that Medicare stop paying for GPs to interpret ECGs. On the contrary, the taskforce explicitly recommended the opposite. </p>
<p>The <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/F9DA276B6A541A82CA2581C2006F875C/$File/MBS%20Review%20Taskforce%20Recommendations%20-%20Cardiac%20Services%20Report%20PDF%20version.pdf">344-page final report of the taskforce’s Cardiac Services Clinical Committee</a> is pretty dry reading, but if you make it as far as page 200 you’ll find it acknowledges the importance of ECGs in general practice. In fact, the report explicitly proposes a new Medicare rebate to “allow all practitioners to take and interpret an ECG when clinically required”.</p>
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<a href="https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Screenshot of a section of the report" src="https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=171&fit=crop&dpr=1 600w, https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=171&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=171&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=215&fit=crop&dpr=1 754w, https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=215&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/350076/original/file-20200729-15-1moearw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=215&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The taskforce’s heart committee recommended Medicare funding all practitioners to take and interpret ECGs.</span>
<span class="attribution"><a class="source" href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/F9DA276B6A541A82CA2581C2006F875C/$File/MBS%20Review%20Taskforce%20Recommendations%20-%20Cardiac%20Services%20Report%20PDF%20version.pdf">Dept of Health</a></span>
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<p>Instead, the federal government has proposed an <a href="http://www.mbsonline.gov.au/internet/mbsonline/publishing.nsf/Content/17C7BC57C362E844CA258591000B2432/$File/Quick%20Reference%20Guide%20-%20Changes%20to%20cardiac%20ECG%2020620.pdf">array of new ECG rebates</a>, none of which would fund GPs to interpret ECGs.</p>
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Read more:
<a href="https://theconversation.com/explainer-what-is-medicare-and-how-does-it-work-22523">Explainer: what is Medicare and how does it work?</a>
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<p>Granted, health policy is a complex area, even when there isn’t a pandemic unfolding. Nevertheless, this seems to be a clear case of expert advice not being translated into policy.</p>
<p>I would urge Hunt and his department to heed the advice of their own expert taskforce, and the concerns raised on behalf of GPs and their patients, and reverse their plans to defund ECG interpretation in general practice – or at least offer a full explanation as to why they are proceeding with this policy.</p><img src="https://counter.theconversation.com/content/143593/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Montgomery works as a general practitioner, mostly academically but also clinically. In his clinical role he and his patients benefit from Medicare funding of his interpretation of ECGs. He is affiliated with several organisations with health policy interests, including the Royal Australian College of General Practitioners, the Doctors Reform Society and the Australian Greens. However, he writes this article in a personal capacity.</span></em></p>Electrocardiograms are a common tool used by GPs to spot heart problems, and every medical student is trained to interpret one. Yet the government plans to remove Medicare funding for GPs to do this.Brett Montgomery, Senior Lecturer in General Practice, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1270392019-11-21T09:36:49Z2019-11-21T09:36:49ZMedical AI can now predict survival rates – but it’s not ready to unleash on patients<figure><img src="https://images.theconversation.com/files/302269/original/file-20191118-66945-14dx24z.jpg?ixlib=rb-1.1.0&rect=12%2C6%2C4268%2C2837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Alongside doctors, AI could be a useful tool for providing better diagnosis. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/medical-healthcare-concept-doctor-hospital-digital-1303352176?src=eec039ff-5685-4d5e-ad20-e64c792e8663-1-45">Victor Moussa/ Shutterstock</a></span></figcaption></figure><p>Researchers recently produced an algorithm that could guess whether heart patients had <a href="https://www.newscientist.com/article/2222907-ai-can-predict-if-youll-die-soon-but-weve-no-idea-how-it-works/">lived or died</a> from their condition within a year. By looking at data from a test of the heart’s electrical activity known as an electrocardiogram or ECG, the algorithm successfully predicted patient survival in 85% of cases. But its developers couldn’t explain how the algorithm did this. Its stated purpose was to find previously unknown information that doctors couldn’t see in ECGs.</p>
<p>Developed by US healthcare provider Geisinger, the algorithm was trained using 1.7 million ECG results from 400,000 patients, including some who had died of heart conditions, and others who had survived. But whether the algorithm can be applied as accurately and fairly to predict new cases as it can with this historic data hasn’t yet been tested. The developers have said trials need to happen to see if similar accuracy levels can be achieved with prediction. While this kind of algorithm has lots of potential, there is reason to remain wary of rushing to use these types of artificial intelligence (AI) systems for diagnosis. </p>
<p>One reason to remain cautious about the algorithm’s findings is because it’s very common for algorithms trained using historic data to become biased. This is because much of the historic data currently used to train algorithms can be overwhelmingly from male and white subjects, which can affect its accuracy. For example, algorithms that could predict skin cancers <a href="https://www.nature.com/articles/nature21056">better than dermatologists</a> turned out to be <a href="https://www.theatlantic.com/health/archive/2018/08/machine-learning-dermatology-skin-color/567619">less accurate when diagnosing dark-skinned people</a> because the system was predominantly trained with data from white people.</p>
<p>Historic data can also contain biases that reflect social disadvantages rather than medical differences, such as if a disease is more common among a minority group because they have worse access to healthcare. Such bias is not just found in <a href="https://science.sciencemag.org/content/366/6464/447">health-related algorithms</a>, but also algorithms for <a href="http://proceedings.mlr.press/v81/buolamwini18a/buolamwini18a.pdf">facial-recognition and photo-labelling</a>, <a href="https://www.reuters.com/article/us-amazon-com-jobs-automation-insight/amazon-scraps-secret-ai-recruiting-tool-that-showed-bias-against-women-idUSKCN1MK08G">recruitment</a>, and <a href="https://www.theguardian.com/uk-news/2019/sep/16/predictive-policing-poses-discrimination-risk-thinktank-warns">policing</a> and <a href="https://advances.sciencemag.org/content/4/1/eaao5580">criminal justice</a>.</p>
<p>As such, the Geisinger algorithm needs further testing to see if prediction rates are similarly accurate for a range of people. For example, is it equally accurate at predicting risk of death for females as it is for males? After all, we know that men and women can have different heart attack symptoms, which <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2760216/">can be seen in ECG results</a>. </p>
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<img alt="" src="https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=373&fit=crop&dpr=1 600w, https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=373&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=373&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=469&fit=crop&dpr=1 754w, https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=469&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/302270/original/file-20191118-66979-hblaro.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=469&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">It’s essential to know if the algorithm is biased when making its diagnosis.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/closeup-view-ecg-machine-display-print-1061157113?src=fdb4c02d-fafb-4493-b13a-254ed222c106-1-14">reddees/ Shutterstock</a></span>
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<p>The Geisinger model is also a <a href="https://towardsdatascience.com/the-black-box-metaphor-in-machine-learning-4e57a3a1d2b0">“black box” system</a>, meaning the decisions it makes can’t be explained by experts and so may have biases that its developers don’t know about. While many researchers and policy makers feel it’s <a href="https://www.wired.com/story/ai-experts-want-to-end-black-box-algorithms-in-government/">unacceptable to develop “black box” algorithms</a> because they can be discriminatory, the speed with which many algorithms have been developed means there are currently <a href="https://www.nysenate.gov/legislation/bills/2019/s3971">few laws</a> and <a href="https://www.eugdpr.institute">regulations</a> in place to ensure that <a href="https://www.wyden.senate.gov/imo/media/doc/Algorithmic%20Accountability%20Act%20of%202019%20Bill%20Text.pdf">only unbiased fair AI models</a> are being developed. </p>
<p>One solution could be to create “<a href="https://www.forbes.com/sites/cognitiveworld/2019/07/23/understanding-explainable-ai/#482267897c9e">explainable AI” (XAI)</a>. <a href="https://towardsdatascience.com/understanding-model-predictions-with-lime-a582fdff3a3">These</a> are systems designed to allow researchers see what <a href="https://christophm.github.io/interpretable-ml-book/shapley.html">key data features</a> an algorithm is focusing on, and how it reached its decision. This may help them minimise any biases the algorithm may have. </p>
<p>Other <a href="https://womenleadinginai.org/report2019">guidelines</a> and standards can also help researchers develop <a href="https://www.wired.com/story/what-does-a-fair-algorithm-look-like/">fairer and more transparent AI</a>. The <a href="https://standards.ieee.org/project/7003.html">IEEE P7003</a> standard shows developers how to ensure they identify all affected groups in a data-set, test for any bias, and suggest how to rate and mitigate risk of bias. <a href="https://standards.ieee.org/project/7001.html">IEEE P7001</a> guides how to make an AI transparent and explainable.</p>
<h2>Understanding the algorithm</h2>
<p>Knowing how the Geisinger algorithm makes its decisions is also important so doctors can understand any new features of heart disease risk that the model may have discovered. For example, another algorithm that analysed images to <a href="https://www.nature.com/articles/s41746-019-0105-1">detect hip fractures</a> made its decisions by concentrating on additional clinical data given to it. This revealed the importance of factors such as the patient’s age or whether a mobile scanner was used (indicating the the person was in too much pain to travel to the main scanner). </p>
<p><a href="https://medium.com/datadriveninvestor/deep-learning-exploits-clinical-reasoning-to-predict-hip-fracture-in-x-rays-e1fd9f1a57d2">Research has shown</a> that looking at both the images and the clinical data makes for more accurate diagnoses. But, if researchers can’t explain how the algorithm made its prediction, it might mean the algorithm can’t be developed more for later use in diagnosis. </p>
<p>If doctors are unaware of the features that an algorithm looks at, they might include those features in their own analysis as well as their algorithm’s findings. This would effectively count the features twice, over-emphasising their importance and potentially even producing a misdiagnosis. Doctors could also become over-reliant on the algorithm, might interact less with patients, and could potentially <a href="https://files.eric.ed.gov/fulltext/EJ1106538.pdf">affect doctors’ overall skill levels</a>.</p>
<p>For example, <a href="https://www.nature.com/articles/s41591-018-0335-9">researchers that designed an AI</a> to diagnose childhood diseases (such as bronchitis and tonsillitis) found its diagnoses were better than those of junior doctors. However, senior doctors were still able to make more accurate diagnoses than the AI. So, if not used correctly, such systems could risk doctors never reaching the skill level of current senior doctors. </p>
<p>For this reason, it’s important to consider how such systems are implemented, and whether they’re in line with <a href="https://www.gov.uk/government/publications/code-of-conduct-for-data-driven-health-and-care-technology">sector level guidance</a>. Leaving the final diagnosis to a doctor could potentially make an app’s diagnoses more accurate, and prevent deskilling. This would particularly be the case if the model was clearly explainable, and any biases made evident to the doctor. </p>
<p>Although the Geisinger algorithm could predict if someone had survived or not, it’s important to remain cautious of these kind of claims, as AI can contain faults based on how it’s trained and designed. AI systems should augment human decision making and not replace it or health providers. As the Geisinger team advise, this AI has the potential for interpreting ECGs as part of a wider diagnostic toolkit – and is in fact not a way to predict if someone will die or not.</p><img src="https://counter.theconversation.com/content/127039/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Allison Gardner works for Keele University as a Computer Science Lecturer and consults with Yoti on bias in algorithms. She is also a councillor in Newcastle-under-Lyme and member of the Labour Party, Founder of Women Leading in AI and member of the Fabian Society</span></em></p>An AI trained to look at heart scans was able to successfully predict risk of death. But one expert cautions we still need to be careful about designing – and using – AI for medical diagnosis.Allison Gardner, Teaching Fellow in Bioinformatics/ Head of Foundation Year Science, Keele UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1034302018-09-19T20:13:56Z2018-09-19T20:13:56ZYour Apple Watch can now record your ECG – but what does that mean and can you trust it?<figure><img src="https://images.theconversation.com/files/237025/original/file-20180919-158222-s8owz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Apple's smart watch can now read your heart current.</span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p>Apple’s new, fourth-generation watch has an <a href="https://www.apple.com/uk/newsroom/2018/09/redesigned-apple-watch-series-4-revolutionizes-communication-fitness-and-health/">electrical heart rate sensor</a>. This can record your electrocardiogram or ECG, which Apple says:</p>
<blockquote>
<p>… can classify if the heart is beating in a normal pattern or whether there are signs of atrial fibrillation (AFib), a heart condition that could lead to major health complications.</p>
</blockquote>
<p>So, what actually is an ECG and can you really rely on a watch to read it?</p>
<h2>How does the heart beat?</h2>
<p>As a quick summary, your heart is divided into four chambers. The two top chambers (called atria) receive blood and push it towards the two bottom chambers (ventricles), which pump blood out to the body (left side) and the lungs (right side).</p>
<p>At the top of the right atrium is a little collection of cells called the sinoatrial node, or SA node. These generate an electrical signal which travels toward the middle of the heart (atrioventricular node). Finally, this electrical impulse spreads into the ventricles, which makes them squeeze blood for what we feel as a heartbeat or pulse. A <a href="https://theconversation.com/what-should-my-heart-rate-be-and-what-affects-it-98945">normal heart rate</a> can vary significantly between different people.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-should-my-heart-rate-be-and-what-affects-it-98945">What should my heart rate be and what affects it?</a>
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</em>
</p>
<hr>
<p>So, these small electrical currents help co-ordinate each beat. In the early 1900s, Willem Einthoven developed a machine to be able to record these signals (for which he was awarded the Nobel Prize) – a device that developed into the modern-day ECG machine. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=601&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=601&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=601&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=755&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=755&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237020/original/file-20180919-158237-17p8ni1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=755&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Your heart is made up of four chambers.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>An ECG involves having small stickers applied to your chest, shoulders and ankles, which can then read the electricity coming from your heart. You don’t feel anything when it is taken and it takes only a few seconds to make a recording. It can be done at your local GP clinic or in hospital.</p>
<h2>How does an ECG work?</h2>
<p>With every beat, there is a characteristic appearance of each signal on the ECG, with separate “waves” that correspond to electrical activity from different parts of the heart.</p>
<p>The P wave (before the spike) represents the atria squeezing blood down towards the ventricles. The QRS looks like a spike and represents the two ventricles squeezing blood to the body and lungs. And the T wave at the end reflects the recovery of the ventricles as they relax to receive blood again.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=661&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=661&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=661&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=830&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=830&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237024/original/file-20180919-158240-ijzvu6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=830&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Each beat is represented by a separate wave or spike on the ECG.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>By analysing various segments, the person reading the ECG can understand about problems, signalled by an abnormal-looking ECG, in the heart. The ECG can usually detect severe or urgent heart attacks, which cause elevation of the segment between the QRS and T waves. Smaller heart attacks sometime show signs, but not always. </p>
<p>The ECG is good for detecting arrhythmias, which are abnormal rhythms. The most common arrhythmia is atrial fibrillation (AF) – this is where the top chambers (the atria) don’t squeeze properly. As a result blood can stagnate and form a clot, which can then go to the brain and cause a stroke. </p>
<p>You can see atrial fibrillation on an ECG when no P wave is visible. Instead there are often small irregular blips indicating that the atrium is beating in a weak and disorganised way. An ECG can also pick up other arrhythmias, though it is most useful if the person is in the abnormal rhythm at the time the ECG is done.</p>
<p>The ECG can also pick up abnormal heart structures. Sometimes it can show signs of the heart being weak (heart failure) or if the muscle is unusually thick, such as when people have high blood pressure for a long time. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/tom-petty-died-from-a-cardiac-arrest-what-makes-this-different-to-a-heart-attack-and-heart-failure-85245">Tom Petty died from a cardiac arrest – what makes this different to a heart attack and heart failure?</a>
</strong>
</em>
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<hr>
<h2>So, can the Apple Watch actually read your heart?</h2>
<p>The ECG at your local doctor is called a 12-lead ECG. Only ten leads are physically attached to you, but the machine derives 12 based on the direction of electrical flow. Each of these leads provide a different view of the heart. </p>
<p>Imagine you are peering into a room through several windows. Each window would give you a different perspective, and putting these together can give you an overall impression of the room.</p>
<p>Wearable ECGs, like that with the Apple Watch, can pick up only one lead (for your further reading, it’s lead I). This can tell if your heart is irregular and sometimes if there is no P wave (so it could potentially detect atrial fibrillation). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/237018/original/file-20180919-143281-1fed0br.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An ECG involves several stickers placed on your chest.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>A key advantage of having the Apple Watch is the ability to take a 30-second ECG (this requires you to put your right hand on the watch to form a circuit so the electrical signals can be read from both arms through your heart) at the time you feel symptoms. It can understand the context as well (for example, your activity level at the time). </p>
<p>There are drawbacks, though. The watch can only give a single-window view of what’s happening in the heart, and won’t be able to detect heart attacks or abnormal heart structure accurately. Wearable devices are also more prone to interference with the signal as they rely on just one lead, whereas a 12-lead ECG remains the gold standard.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-apple-watch-adds-heart-tracking-heres-why-we-should-welcome-ecg-for-everyone-103375">New Apple Watch adds heart tracking: here's why we should welcome ECG for everyone</a>
</strong>
</em>
</p>
<hr>
<p>And, of course, the actual ECG must be read by a professional. Apple gives you the option to download your reading as a PDF. </p>
<p>Ultimately, if you have concerns about your heart, an ECG is a simple, non-invasive, cheap test, which your local doctor can interpret. It should always be accompanied by a detailed history of your symptoms and a physical examination.</p><img src="https://counter.theconversation.com/content/103430/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shane Nanayakkara receives funding from the Heart Foundation and the Baker Heart and Diabetes Institute. </span></em></p><p class="fine-print"><em><span>Anna Beale does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The new Apple Watch is making waves for being able to record an electrocardiogram (ECG) and share it. An ECG can tell you what’s going on with your heart.Shane Nanayakkara, Cardiologist, Baker Heart and Diabetes InstituteAnna Beale, Medical doctor, PhD candidate in cardiology, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1033752018-09-18T12:23:56Z2018-09-18T12:23:56ZNew Apple Watch adds heart tracking: here’s why we should welcome ECG for everyone<figure><img src="https://images.theconversation.com/files/236854/original/file-20180918-158243-1km8z6o.jpg?ixlib=rb-1.1.0&rect=46%2C0%2C5184%2C3453&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/women-wear-hand-watch-running-motion-331673009?src=Hb2rY9pOMnx1gNDCY2OcYQ-1-5">Shutterstock</a></span></figcaption></figure><p><a href="https://www.forbes.com/sites/gordonkelly/2018/08/28/apple-iphone-9-x-plus-xplus-release-date-specs-price-cost-iphone-xs/#5cad5ce925dd">Leaked details</a> of the new iPhone models were quickly relegated to second tier headlines after Apple’s latest product announcement. More people seem to be excited about the fact that <a href="https://www.apple.com/uk/newsroom/2018/09/redesigned-apple-watch-series-4-revolutionizes-communication-fitness-and-health/">the new Apple Watch</a> will come with a built-in heart monitoring electrocardiogram (ECG) function.</p>
<p>An ECG <a href="https://www.nhs.uk/conditions/electrocardiogram/">is a simple test</a> that can be used to check your heart’s rhythm and electrical activity, designed to detect any underlying issues. The Apple Watch 4 will be the first mainstream wearable gadget to integrate this kind of medical diagnostic technology. (<a href="https://theconversation.com/how-reliable-is-your-wearable-heart-rate-monitor-98095">Other devices</a> such as the Fitbit typically measure blood flow by <a href="https://arstechnica.com/gadgets/2017/04/how-wearable-heart-rate-monitors-work-and-which-is-best-for-you/">shining a light</a> through the skin. This should be an exciting breakthrough, but Apple’s revelation has been met with a <a href="https://www.wired.co.uk/article/apple-watch-heart-ecg-fda">mixed reception</a>.</p>
<p><a href="https://jamanetwork.com/journals/jama/fullarticle/2684614">There isn’t yet enough evidence</a> to show that using an ECG in general to screen people for cardiovascular diseases ultimately makes them healthier. In fact, <a href="https://jamanetwork.com/journals/jama/fullarticle/2684613">it’s not recommended</a> for screening people who are at low risk of developing problems because it could produce false positive results (indicating a problem where none really exists). This can then lead healthy people to seek unnecessary, invasive and potentially harmful treatments, at a cost to the health service provider, as well as producing increased anxiety. For those who are at high risk of disease, ECG results might suggest medical intervention when lifestyle changes could actually be more beneficial. But does this really mean the technology shouldn’t be made more widely available?</p>
<p>It would be naive to assume that everyone who is at risk of heart problems knows, never mind consults with a doctor, about it. Often, people don’t realise until it is too late and they need emergency treatment and lengthy retrospective investigation – or, at worse, they die. To ignore the current digital health movement, and surging enthusiasm for it among early adopters of devices, health enthusiasts and growing numbers of people more generally would also be foolish. </p>
<p><a href="https://www.statista.com/topics/4393/fitness-and-activity-tracker/">The industry is booming</a>. The growing numbers paying to monitor their health with fitness trackers and smart watches has shown how <a href="http://www.mdpi.com/2227-9709/4/1/5/htm">engaged and motivated</a> people can become. We shouldn’t be denying people opportunities to take greater responsibility for their health, particularly as health services come under growing pressure from an ageing and <a href="https://www.theguardian.com/society/2018/jan/24/number-of-britons-living-with-chronic-illnesses-set-to-rise">increasingly ill</a> population.</p>
<p>The physical risks associated with performing ECGs are minimal. Sensors attached to the skin are used to detect the electrical signals produced by your heart each time it beats. It is <a href="https://www.nhs.uk/conditions/electrocardiogram/">quick, safe and painless</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=392&fit=crop&dpr=1 600w, https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=392&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=392&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=493&fit=crop&dpr=1 754w, https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=493&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/236855/original/file-20180918-158243-u83va1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=493&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The first mainstream wearable device with ECG.</span>
<span class="attribution"><span class="source">Apple</span></span>
</figcaption>
</figure>
<p>We shouldn’t <a href="https://www.wired.com/story/ecg-apple-watch/">ignore concerns</a> that an ECG test in a commercially available watch could encourage many people to make additional trips to the doctor when they have recorded any anomalous activity. A rush of gadget-adorned people descending on clinics demanding services is a worry. But many people already self-diagnose conditions or agonise about symptoms unnecessarily, often caused by using the internet and other technology. Those who do use the Apple Watch ECG may well include large numbers of <a href="https://www.iol.co.za/lifestyle/health/fitness/fitbit-fad-threatens-to-drive-up-gp-visits-from-worried-well-17065632">“worried well”</a>. But the impact of uncontrolled use of ECG technology seems likely to be limited for the moment, especially as many people will still simply be unable to afford it.</p>
<p>If ECG is added to the list of readily available health technology applications, it will be little different from enabling people to detect their pulses, count their steps, track their periods and analyse their sleep. An Apple Watch ECG won’t be conducted under controlled conditions, but this is true of so many health consultations.</p>
<h2>Personal health tech is already common</h2>
<p>Medical staff now give out many interventions that can be performed independently at home. This includes some <a href="http://journals.sagepub.com/doi/10.1177/2055207616678498">self-tracking</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6001233/">technologies</a> and sensitive diagnostic tests, such as those for <a href="https://www.nhs.uk/live-well/healthy-body/how-to-use-self-test-kits-safely/">sexual health and bowel screening</a>. In some places, you can even swap the GP’s surgery for a <a href="https://www.gpathand.nhs.uk/">smartphone app</a>.</p>
<p>While accuracy may be an issue with the Apple Watch ECG, the same is true for ECG tests performed in clinics and interpreted by professionals, according to <a href="https://scholar.google.co.uk/scholar?as_ylo=2018&q=ecg+accuracy&hl=en&as_sdt=0,5">many papers published on this topic</a>. Of course, technologies can always be improved, but waiting until a test is close to perfect isn’t necessarily the best way to use it. </p>
<p>Ultimately, we are living in a digital age and healthcare has so far been slow to revolutionise. We should be <a href="https://digital.nhs.uk/about-nhs-digital">harnessing technology to improve healthcare</a>. Everyday ECG won’t replace medical care but might help people to spot important warning signs and seek expert opinion. The real-time data the device has already collected may then help inform a medical expert’s interpretation and diagnosis.</p>
<p>What we should really be thinking about is how we can widen appropriate access for this kind of technology to those who it would most benefit, so that it might identify more people at risk, earlier. This would help make health services more efficient, reduce waste and perhaps even save lives.</p><img src="https://counter.theconversation.com/content/103375/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather May Morgan led a feasibility study (unfunded) in partnership with CloudTag Inc. (<a href="http://www.cloudtag.com/">http://www.cloudtag.com/</a>) in summer 2017, which used its Onitor Track (unpublished). She previously received funding for research into digital health from The Wellcome Trust through the University of Aberdeen’s Institutional Strategic Support Fund under Grant RG12724-13. Heather is presently an Apple Watch 3 user for research and life purposes.</span></em></p>Gadgets that tell too many people to go to the doctor are a worry, but the growing enthusiasm for health monitoring should be encouraged.Heather May Morgan, Lecturer in Applied Health Sciences, University of AberdeenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/989452018-07-08T19:59:36Z2018-07-08T19:59:36ZWhat should my heart rate be and what affects it?<figure><img src="https://images.theconversation.com/files/225865/original/file-20180703-116129-1u8nw9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fitness makes the heart rate slower, which appears to be better for health and longevity. </span> <span class="attribution"><span class="source">from www.shutterstock.com</span></span></figcaption></figure><p>Humans have been aware of their heart rate for <a href="https://www.hindawi.com/journals/crp/2011/164832/">thousands of years</a>. But knowing the meaning behind the beats isn’t so simple. </p>
<p>Myriad factors affect our heart rate, including our age, medical conditions, medications, diet, and fitness level. Today, we’re even more aware of our heart rate, thanks to devices such as smartwatches that can measure every beat during rest and exercise. So, what is normal?</p>
<h2>How should we measure our heart rate?</h2>
<p>Surprisingly, there are over twelve places you can feel your pulse. But there are two that are the easiest and most reliable – the radial artery, which runs along the inside of the forearm from the base of the thumb; and the carotid artery, which runs up the front of the neck two fingers to the side of the Adam’s apple. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=327&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=327&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=327&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=411&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=411&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225431/original/file-20180629-117425-iipfrh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=411&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A: measurement of carotid pulse B: measurement of radial pulse.</span>
<span class="attribution"><span class="source">Source</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The best way to measure heart rate is to sit down for a few minutes and relax, then use two fingers (not your thumb, as its own pulse can confuse your measurement) to gently compress the artery and count the beats over 15 seconds. Multiplying this by four will give your heart rate in beats per minute. </p>
<p>If you’re using the carotid, it’s important to only check one side at a time, and not to massage the artery – this is an area that <a href="https://www.nhs.uk/Conditions/Supraventricular-tachycardia/Documents/carotid_sinus_massage_leaflet%5B1%5D.pdf">senses blood pressure</a> flowing through the artery and signals to the heart to keep it in a tight range; stimulating this area can trick it into dropping the heart rate and blood pressure, leading to a blackout. </p>
<p>Your heart runs on electricity – in fact, every single heartbeat is the result of a tiny electrical impulse travelling through your heart muscle. These impulses can be measured using an an <a href="https://www.healthdirect.gov.au/electrocardiogram-ecg">electrocardiogram (ECG)</a>, which is the most reliable and informative measure of your heart rate. The test is non-invasive, painless, and you can get it at most GP practices and pathology services.</p>
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<a href="https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225867/original/file-20180703-116117-xtr3v7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An ECG is the most accurate reading of your heart rate.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>Wearable devices such as smartwatches use <a href="https://en.wikipedia.org/wiki/Photoplethysmogram">light</a>, rather than pressure, to measure heart rate. As the volume of small arteries in the wrist transiently increase with each heart beat, the amount of light reflected back to a conductor in the watch changes – and the frequency with which these fluctuations occur is the heart rate.</p>
<p>They’re an attractive way to have real-time heart rate recording during rest and activity, but they have inherent limitations due to the simplicity of their design, and interference caused by movement can often interrupt their recordings. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-reliable-is-your-wearable-heart-rate-monitor-98095">How reliable is your wearable heart-rate monitor?</a>
</strong>
</em>
</p>
<hr>
<h2>What is a normal heart rate and what affects it?</h2>
<p>As an adult, the normal range for resting heart rate is 60 to 100 beats per minute. This applies for anyone over the age of 17 – infants and children <a href="https://www.rch.org.au/clinicalguide/guideline_index/Normal_Ranges_for_Physiological_Variables/">have faster heart rates</a> due to their smaller body and heart size. This “normal” range for heart rate doesn’t change across the adult lifespan. </p>
<p>Lots of things can cause your heart rate to speed up (known as tachycardia):</p>
<ul>
<li><p>exercise: when you exercise, your heart rate needs to increase to pump more blood around your body. A normal person pumps around five to six litres per minute, and an average person can get up to 20 litres a minute while exercising – athletes can even go as high as 35</p></li>
<li><p>coffee and energy drinks: caffeine increases your heart rate by <a href="https://www.livestrong.com/article/481979-the-effects-of-caffeine-on-adenosine/">blocking adenosine</a>. This a chemical in the brain that causes drowsiness and slows heart rate</p></li>
<li><p>stress: stress and excitement cause activation of the <a href="https://en.wikipedia.org/wiki/Sympathetic_nervous_system">sympathetic nervous system</a>, which was biologically designed to help us hunt for food or run away from animals. But in the modern day it tends to be activated more when we have a difficult conversation at work, or watch <a href="https://mashable.com/2017/08/10/game-thrones-cardiogram-heart-rate/#lf1FHM3PyOqj">Game of Thrones</a></p></li>
<li><p>infection: serious infections, particularly when they spread into the bloodstream (sepsis), put more strain on the heart as more blood flow is required to carry immune cells from the bone marrow and lymph glands to target the infection. A faster heart rate alerts doctors the infection is severe</p></li>
<li><p>thyroid disease: your thyroid is a gland in your neck that works to maintain your metabolism – an overactive <a href="https://en.wikipedia.org/wiki/Hyperthyroidism">thyroid gland</a> can increase the heart rate, along with causing weight loss, irritability, heat intolerance and diarrhoea</p></li>
<li><p>heart arrhythmias: the heart’s normal electrical activity can also be interrupted, leading to tachyarrhythmias, where the heart is beating fast and abnormally. <a href="https://theconversation.com/why-palpitations-or-an-irregular-heartbeat-need-urgent-attention-74568">Atrial fibrillation</a> is the most common arrhythmia, where the pulse becomes irregular, and can cause symptoms such as palpitations, shortness of breath and light-headedness. One of its more serious complications is stroke. </p></li>
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<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/getting-to-the-heart-of-the-matter-on-stroke-7180">Getting to the heart of the matter on stroke</a>
</strong>
</em>
</p>
<hr>
<p>What about going slow, or bradycardia? Again, there are a few common reasons:</p>
<ul>
<li><p>relaxation: the heart rate slows as we relax and the counterpart to the sympathetic nervous system, the <a href="https://en.wikipedia.org/wiki/Parasympathetic_nervous_system">parasympathetic nervous system</a>, which helps us to “rest and digest” is activated</p></li>
<li><p>medications: many tablets can slow down heart rate (some deliberately to ease the load on the heart), such as beta-blockers, antidepressants and opioid type painkillers</p></li>
<li><p>physical fitness: exercise training and cardiovascular fitness causes a lower resting heart rate, and it can be quite normal for athletes to have resting heart rate in the 40s. <a href="https://www.baker.edu.au/research/laboratories/sports-cardiology/project-bradycardia-athletes">It’s not entirely clear</a> why this happens, but the predominant mechanism behind it is <a href="https://www.ncbi.nlm.nih.gov/pubmed/11897447">changes</a> to the electrical conducting system of the heart that happen with exercise training </p></li>
<li><p>heart arrhythmia: arrhythmias can also slow down your heart. Heart block occurs when the electrical signals, which originate at the top of the heart in the atria, are not conducted properly to the ventricles at the bottom of the heart. This can be life-threatening, as although the ventricles have an intrinsic backup system to beat at approximately 40 beats per minute, this can fail and <a href="https://lifeinthefastlane.com/ecg-library/basics/complete-heart-block/">cause the heart to stop completely</a>. There are various types of heart block, which range in severity from no symptoms at all to frequent blackouts or sudden death. Those at the more severe end of the spectrum may need a pacemaker to stimulate the heart to beat.</p></li>
</ul>
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<a href="https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/225868/original/file-20180703-116152-1kyiz6l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wearable devices are great for keeping an eye on your heart rate, but be aware they’re not always accurate.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>What heart rate should we aim for?</h2>
<p>Although the “normal” range of heart rate is quite broad at 60-100, there’s increasing evidence having a heart rate at the lower end of the spectrum is better for you. </p>
<p>In a <a href="https://jamanetwork.com/journals/jamacardiology/article-abstract/2670454">large US study</a>, a higher heart rate was associated with a greater incidence of heart attacks, strokes, heart failure and early death from heart-related and non-heart-related causes. In patients who have a history of heart attacks, having a lower heart rate <a href="https://www.sciencedirect.com/science/article/pii/S0021915010000778">seems to be better</a>, and we often give tablets to slow down the heart. </p>
<p>But the converse is true when we exercise. Most people’s peak heart rate when exercising should be no more than <a href="https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise-intensity/art-20046887">220 minus their age</a> (so, 190 for a 30 year old, 160 for a 60 year old). If your heart rate is more than 10-20 beats higher than your age maximum when exercising, this could be due to abnormal conduction of the heart. </p>
<p>“<a href="http://circ.ahajournals.org/content/123/9/1010">Chronotropic incompetence</a>” is when the heart is unable to increase its rate in proportion to increased demand (exercise), and it’s a bad sign when the heart can’t lift its rate as much as it needs to. The ability of the heart rate to drop back down to normal after exercise is also important (heart rate recovery) – failure to do so also predicts a <a href="https://www.nejm.org/doi/full/10.1056/nejm199910283411804">higher probability of early death</a>.</p>
<h2>Can I change my heart rate?</h2>
<p>More important than trying to reach a lower heart rate is just trying to do more of the things we know keep us healthy. Plenty of exercise (at least 30 minutes five times a week at moderate intensity), relaxation, a healthy diet, and keeping a careful eye on your blood pressure and waistline will all help. </p>
<p>Wearable devices are great at providing you with heart rates, but be aware they’re not always accurate, and if you’re getting abnormal readings, particularly if you have symptoms, then you should see your doctor.</p><img src="https://counter.theconversation.com/content/98945/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shane Nanayakkara receives funding from the National Heart Foundation and the Baker Heart and Diabetes Institute. </span></em></p><p class="fine-print"><em><span>Anna Beale does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The adult heart rate should be between 60 and 100 beats per minute,but lots of factors can affect this.Anna Beale, Medical doctor, PhD candidate in cardiology, Monash UniversityShane Nanayakkara, Cardiologist, Baker Heart and Diabetes InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/847592017-10-05T22:01:53Z2017-10-05T22:01:53ZA war made me realize: The world needs biomedical engineers<figure><img src="https://images.theconversation.com/files/188928/original/file-20171005-2140-1tryt5m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Biomedical engineering involves the application of engineering solutions to medical problems. Employment in the field is projected to grow 23 per cent from 2014 to 2024.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>It was a sunny and pleasant spring day in Dezful, a small city in the south part of Iran. There were not many people on the street but I remember a young teenager pedalling slowly on his bike. I remember him because a moment later he was decapitated by a piece of metal when an Iraqi missile hit the neighbourhood. </p>
<p>His headless body pedalled for a while before falling to the ground. Everything in that moment registered in my brain like a scene in slow motion. </p>
<p>In shock, all I was thinking was: “Wow! How can the body balance without the brain? The body’s motion must have also been programmed in the spinal cord!”</p>
<p>It was spring of 1981 and I was 20 at the time, a second year university student with no background in biology or human physiology. A year earlier, I wanted to become a nuclear physicist and work on a Nobel Prize winning project. Then the war between Iran and Iraq started and the universities closed. I went to the Red Cross and to hospitals to learn first aid and then to the fronts to help with the war casualties. </p>
<p>The war scenes — and particularly the teenage cyclist on that particular day — made me decide to become a biomedical engineer. </p>
<h2>Engineering knowledge, medical problems</h2>
<p>Biomedical Engineering (BME) is now one of the fastest growing fields. Molecular Biology advances were the first modern revolution. Genomics was the second. Now the convergence of the life sciences and engineering as Biomedical Engineering is referred to as <a href="http://news.mit.edu/2016/strategy-convergence-research-transform-biomedicine-0623">the third revolution</a>. </p>
<p>But what is BME? And who can be called <a href="http://www.bmes.org/content.asp?contentid=140">a biomedical engineer</a>? The simplest and most informative definition is this: BME is the application of engineering knowledge and skills to challenging medical problems. </p>
<p>We can learn from examples. One of my heroes is the late <a href="https://en.wikipedia.org/wiki/Paul_Bach-y-Rita">Dr. Paul Bach-y-Rita</a>, a physician and researcher at Wisconsin University. When young Paul had just started his engineering studies, a friend of his father told him he could never become a physician. To prove that friend wrong, Paul quit engineering and went to study medicine. Thus, he became a medical doctor with an engineering mind. </p>
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<figcaption><span class="caption">A short 10 minute story by Wired Science called ‘Mixed Feelings’ showcasing the work of the late, great Paul Bach-y-Rita and his revolutionary work in neurosplasticity.</span></figcaption>
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<p>Dr. Bach-y-Rita created two major life-changing technologies: one was for a woman with complete lack of balance; the other was for the blind to see again. In both of his great inventions, he used the tongue as the sensory input. </p>
<p>He used the brain’s plasticity to rewire the brain to use tongue nerve signals instead of vestibular (balance) signals and instead of eyes. I encourage you to read about his technologies on <a href="https://subject-zero.com/aknowledgements/paul-bach-y-rita/">vestibular replacement</a> and <a href="http://discovermagazine.com/2003/jun/feattongue">the “seeing tongue.”</a> </p>
<h2>Medical devices for sleep apnea</h2>
<p>A biomedical engineer must be multilingual, as every field of science has its own lingo. For example, in my team, we develop medical devices for diagnosis and treatment of sleep apnea. It is not enough to have electronics knowledge and skill; one must also have in-depth knowledge of upper airway physiology, sleep apnea pathophysiology and the characteristics of the signals that are being recorded. </p>
<p>That is why I am a firm believer that a biomedical engineer must have experience in the recording and analysis of basic human biological signals — such as those of the muscles, heart, brain and respiration.</p>
<p>Design of medical devices for diagnosis and rehabilitation is only one of many different research fields in which BME is pushing the boundaries. However, advances in science occur in incremental steps. </p>
<p>As an example, <a href="https://ecglibrary.com/ecghist.html">electrocardiography (ECG)</a> is now the very first vital signal recorded and monitored in most clinical routines. Yet it took many scientists experimenting over many years, from <a href="http://www.batteryfacts.co.uk/BatteryHistory/Galvani.html">Galvani’s famous electricity experiment on frogs’ legs</a> in 1786, until the construction of the first commercialized ECG device in the 20th century by Einthoven <a href="https://www.nobelprize.org/nobel_prizes/medicine/laureates/1924/einthoven-bio.html">(who subsequently received the Nobel Prize in Medicine)</a>. </p>
<h2>Customised prosthetics and robotic devices</h2>
<p>Not every biomedical engineer has to become a researcher. A biomedical engineer may work and serve society in many different ways and the job market is growing rapidly. An <a href="https://www.bls.gov/ooh/architecture-and-engineering/biomedical-engineers.htm">analysis from the US Bureau of Labor Statistics</a> projects employment in biomedical engineering to grow 23 per cent from 2014 to 2024 — much faster than other occupations. </p>
<p>Biomedical engineers are also involved in performance testing of new and proposed products. Government positions often involve product-testing and establishing safety standards for devices. In hospitals, biomedical engineers can advise on selection, use and maintenance of medical equipment or life-support systems. They also build customized devices for special health care or research needs including prosthetic and robotic devices to increase quality of life. </p>
<p>In research institutions, biomedical engineers supervise laboratories and equipment. They can direct research activities in collaboration with colleagues in medicine, physiology, pharmaceuticals, nursing and other engineering disciplines. </p>
<p>Some biomedical engineers are technical advisors for marketing departments of companies or in management positions. Others take more advanced training in fields such as medicine to bridge particular deficiencies in the increasingly integrated approach to health care.</p>
<h2>One student-centered graduate program</h2>
<p>At the University of Manitoba, we designed our graduate BME program as a multidisciplinary initiative involving the faculties of engineering, medicine and science. We accept students with backgrounds in engineering or science and train them to become biomedical engineers. </p>
<p>The main innovation of this program is not its concept nor its content - there are many other similar programs in North America - but its functional interdisciplinary design. Another is its admission’s flexibility: the program admits students from a wide variety of backgrounds, and tailors each student’s program to their needs. </p>
<p>The main research areas of the program include but are not limited to: medical instrumentation and sensors, biological signal processing, biomedical image processing and reconstruction, gait analysis and rehabilitation, biophotonics, orthopaedic mechanics, neurocognitive science and non-invasive diagnosis of neurological disorders. </p>
<p>Why study in such a program? As I always say to my new graduate students: our research can bring us fame but we do not work for fame; our research can bring us money but that is not our incentive either; we do biomedical engineering because humanity needs it. </p>
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<p class="fine-print"><em><span>Zahra Moussavi works for University of Manitoba as an academic and director of Biomedical Engineering Program. She does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.</span></em></p>One professor explains how war in Iran led her to a career in biomedical engineering - a rapidly growing field that offers students exciting opportunities to serve humanity.Zahra Moussavi, Professor of Biomedical Engineering, University of ManitobaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/27942011-08-11T21:21:26Z2011-08-11T21:21:26ZTattoo you: the stick-on medical revolution<figure><img src="https://images.theconversation.com/files/2855/original/kim3HR.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The epidermal electronic system can measure your vital signs in a completely unobtrusive way.</span> <span class="attribution"><span class="source">John A. Rogers</span></span></figcaption></figure><p>When you think of tattoos you probably imagine bikies, <a href="http://www.dailytelegraph.com.au/entertainment/movies/mike-tysons-tattoo-artist-is-suing-warner-bros-over-a-similar-looking-tattoo-used-in-the-hangover-part-ii-movie/story-e6frexli-1226060912410">celebrity tats</a> or that Japanese flourish on your left foot that means “Honour” (or so you think).</p>
<p>You probably don’t picture medical revolution … which is what tattoos may now represent. Well, temporary tattoos, at least. </p>
<p>Work <a href="http://www.sciencemag.org/content/333/6044/838.abstract">published today in Science</a> shows how a simple stick-on tattoo could be used in a medical context.</p>
<p>Think of a patient in hospital overnight with a heart complaint. With existing technology, the patient might be hooked up to an <a href="http://www.nlm.nih.gov/medlineplus/ency/article/003868.htm">electrocardiogram (ECG) device</a> in order to monitor their heart.</p>
<p>Those devices use <a href="http://www.gereonics.com/electrodes.html">skin electrodes</a> to pick up readings from the patient but unfortunately, there are significant drawbacks to using electrodes.</p>
<p>Worn for more than a few hours, they can start to leave marks, and on sensitive people (or when left on for longer than recommended) they can leave some impressive welts.</p>
<p>In the case of non-disposable electrodes, the application of conductive gel and cleaning (or even abrasion) of the skin is required.</p>
<p>The new development by Dae-Hyeong Kim and colleagues at the University of Illinois could put an end to the use of surface electrodes forever.</p>
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<p></p><figcaption>Wearable electrodes are virtually invisible. <span>Video courtesy of John A. Rogers</span></figcaption> <p></p>
<p>Using recent developments in nanotechnology, the team has developed a technique for printing electronic circuits on to water-soluble polymer sheets that can be applied like a “temporary tattoo”.</p>
<p>This development blurs the line between biology and electronics and offers nothing less than the possibility of completely unobtrusive, fully wearable, biological monitoring – with no electrodes in sight.</p>
<p>The researchers have dubbed it the “epidermal electronic system” (EES), and it has exciting possibilities in a range of disciplines:</p>
<p><strong>In <a href="http://en.wikipedia.org/wiki/Cardiac_electrophysiology">cardiac electrophysiology</a> (i.e ECG):</strong></p>
<p>Cardiology patients under observation over the course of a day typically wear a <a href="http://www.nlm.nih.gov/medlineplus/ency/imagepages/8810.htm">Holter heart monitor</a>. Such devices are usually attached for a minimum of 24 hours (and often substantially longer) to capture the behaviour of the heart.</p>
<p>By making equipment lighter and wearable, it might be possible to continuously monitor patients who have known cardiac illnesses which put them at risk of heart attack. </p>
<p>A wearable “skin” sensor with an integrated circuit to detect <a href="http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002091/">arrhythmias</a> – irregularities in the heart beat – could conceivably monitor individuals with a known cardiac problem or those who have a high-risk of developing such a condition – people with anorexia, for example.</p>
<p>In my field (heart rate variability), we extract measurements of the <a href="http://www.nlm.nih.gov/medlineplus/autonomicnervoussystemdisorders.html">autonomic nervous system</a> – the part of the nervous system that controls involuntary actions – from the beat-to-beat changes in the heart.</p>
<p>Comfortable, unobtrusive electrodes will allow us to monitor patients or experiment participants over very long periods of time, and investigate the very long-term changes in the variation of the heart. </p>
<p>Currently, we know almost nothing about what these changes represent.</p>
<p><strong>In exercise physiology:</strong></p>
<p>The firing rate and contraction force of the muscles are monitored by surface electrodes of an <a href="http://my.clevelandclinic.org/disorders/electromyograms/hic_electromyograms.aspx">electromyogram (EMG)</a>. </p>
<p>These devices <a href="http://www.cardiff.ac.uk/sohcs/rcck/facilities/physiology/index.html">are quite bulky</a>, and often prevent full, violent or natural movements to be studied while athletes are performing at their peak. (Try running at full speed while carrying an extra device and a dozen electrodes stuck to each leg!) </p>
<p>With a “skin” electrode it may be possible to monitor athletic performance completely without any noticeable difference from normal. </p>
<p>If the information can be accessed in real time, it may be possible to monitor the loss of force development over time during training itself and adjust accordingly – almost as if your muscles were “talking back to you” from under the skin.</p>
<p><strong>In neurology:</strong></p>
<p>One of the main problems with existing <a href="http://www.nlm.nih.gov/medlineplus/ency/article/003931.htm">electroencephalogram (EEG)</a> techniques – measuring the electrical activity of the brain using electrodes placed on the scalp – is the fact that participants are placed in artificial situations: stuck in a lab chair, barely able to move, watching stimuli on a screen.</p>
<p>But with the fully wearable, portable and invisible EES system Kim and colleagues have developed, we could monitor the same signals in real life, as they actually happen.</p>
<p>Moreover, in the case of conditions such as <a href="http://professionals.epilepsy.com/page/lateral_temporal_lobe_epilepsy.html">lateral temporal lobe epilepsy</a>, it may be possible to pick up patterns indicative of seizures, directly from electrodes layered across the surface of the scalp.</p>
<p>All of this is just the beginning.</p>
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<span class="caption">The EES can be applied (and removed) as easily as a stick-on temporary tattoo.</span>
<span class="attribution"><span class="source">John A. Rogers</span></span>
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<p>Kim and colleagues have already tested a number of these possibilities. Soon, instead of merely being passive sensors, the EES might entail whole integrated printed circuits that are able to measure biosignals, correct and analyse those signals, and provide feedback from digital devices in real time, all the time.</p>
<p>Psychophysiological experiments are frequently concerned with “external validity” – whether or not what we measure in the lab sufficiently represents the phenomena we’re trying to model in the real world. </p>
<p>With this system, that concern may soon be a thing of the past, as we won’t even be able to see the equipment. </p>
<p>So how long until we see this technology in Australian hospitals?</p>
<p>Well, if EES systems are <a href="http://www.pharmout.com.au/downloads/white_paper_medical_device_registration_australia.pdf">classified as a medical device</a> – and considering their role, that’s entirely likely – there will be some years of testing before they can be successfully employed in treatment. </p>
<p>It’s very hard to say when any device will be brought to market, but in around two years our laboratory will be asking suppliers if the EES is available for purchase yet.</p>
<p><em>Read more about the EES at <a href="http://theconversation.com/game-changing-printed-tattoos-may-replace-hefty-medical-monitors-2811">our news story</a>.</em></p><img src="https://counter.theconversation.com/content/2794/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Kemp receives research funding from the Australian Research Council and is currently a National Health and Medical Research Council Career Development Research Fellow.</span></em></p><p class="fine-print"><em><span>James Heathers does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When you think of tattoos you probably imagine bikies, celebrity tats or that Japanese flourish on your left foot that means “Honour” (or so you think). You probably don’t picture medical revolution…James Heathers, PhD Candidate in Applied Physiology, University of SydneyAndrew H Kemp, Associate Professor, University of SydneyLicensed as Creative Commons – attribution, no derivatives.