Category Archives: News

SfNIRS Newsletter July 2020

Welcome to the July 2020 issue of the SfNIRS newsletter, which covers the period from March 2020 through June 2020. This period has been dominated by the COVID19 pandemic, which has been difficult for research and business. We have had to adapt to the circumstances, including scarce access to our laboratories, restricted movement, a switch to virtual meetings and conferences, among other things. Nonetheless, it has been a period full of news. Here, you’ll find what we think is a complete summary.

The communications committee looks forward to hearing from you about future news items you’d like to see posted.

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The pulse oximeter, Covid-19 and the legacy of Dr, Takuo Aoyagi

By Rob Cooper.

In the midst of a global pandemic that has seen hundreds of thousands lose their lives to respiratory failure, the Japanese medical device giant Nihon Kohden quietly announced the death at 84 of their long-time employee, Dr. Takuo Aoyagi: the inventor of the pulse oximeter.

The pulse oximeter, which will be familiar to many as the small sensor that clips over a patient’s finger and emits a gentle red glow, is by any measure one of the most successful medical instruments in history. It provides a continuous measurement of pulse rate and blood oxygen saturation- a measure of the level of oxygen in the blood that is a key marker of respiratory and heart failure. A pulse oximeter can be found at the side of every hospital bed and in every operating theatre, while similar technology is increasingly common to consumer devices from fitness trackers to baby monitors.  The pulse oximeter has saved countless lives. Its introduction in the late 1970s coincided with a 90% decrease in deaths during anaesthesia, which is just one area of application.

Blood, Light and Oxygen

The pulse oximeter is, like all great inventions, remarkably simple. It uses two colours of light (usually red and near-infrared) shone through the finger to measure changes in the concentration of the oxygen-rich and oxygen-poor forms of haemoglobin: the molecule that carries oxygen around the bloodstream. This is possible because haemoglobin that is rich with oxygen is a much brighter red colour than haemoglobin that has had its oxygen stripped away by the cells of the body.

The idea that light could be used to yield measurements related to oxygen saturation dates back to the 1870s, and was built upon extensively during WWII in an effort to develop a system to warn allied pilots if their oxygen levels became perilously low. But it was not until 1974, and the work Dr. Aoyagi, that a method was developed to take these optical signals and produce a measure of oxygen saturation that was accurate enough to impact patients.

Noise to Signal

Dr. Takuo Aoyagi was born on 14th February, 1936 in Niigata Prefecture in Japan.  He studied electrical engineering at Niigata University, graduating in 1958. Soon after, Dr. Aoyagi came across a quote from the founder of the Nihon Kohden Corporation, Dr. Yoshio Ogino, which read “a skilled physician can treat only a limited number of patients, but an excellent medical instrument can treat countless patients across the world”. By 1971, Dr. Aoyagi was leading a small team at Nihon Kohden, and had been issued a simple challenge by his manager: “develop something unique”.

Dr. Aoyagi set about developing a sensor that could inform doctors when a patient’s respiratory system was failing to the point where they needed artificial ventilation. Previous efforts to make use of light to measure oxygen levels had failed to yield a useful device because of their dependence on convoluted calibration procedures. One such approach relied on the repeated compression and release of the upper arm.

Dr. Aoyagi’s initial investigations were severely hampered by noise in his optical measurement, noise that was due to the regular surge of oxygenated blood that flows through our bodies with every heartbeat. His real breakthrough came with the realisation that this pulsatile signal could itself provide a method of calibration. By comparing the size of the peaks and troughs that came with each heartbeat, Dr. Aoyagi was able to demonstrate a simple and accurate measurement of the oxygen saturation.

Happy Hypoxia

In the last few weeks, the importance of pulse oximeters in the treatment of coronavirus patients has led to a surge in interest in the now-ubiquitous device. In a New York Times op-ed publish two days after the death of Dr. Aoyagi, emergency physician Dr. Richard Levitan argued that “all persons with cough, fatigue and fevers should have pulse oximeter monitoring even if they have not had virus testing”.  This was in response to patients presenting with what has been misleadingly dubbed “happy hypoxia” – a state of perilously low oxygen saturation that seems to occur in some Covid-19 patients without being accompanied by a shortness of breath.

Dr. Aoyagi’s pulse oximeter would normally read between 90 and 99% in a healthy person, but there have been reports of Covid-19 patients exhibiting oxygen saturations at low as 50% without overt breathing difficulties.

While many clinicians have expressed concern that a surge in the at-home use of pulse oximeters could do more harm than good, Dr. Levitan’s suggestion has been echoed by others, including by some doctors in the UK NHS, who argue that distributing pulse oximeters to the most vulnerable could help identify those developing severe cases of Covid-19.

No matter the outcome of this debate, it is clear that the importance of this small, little-celebrated device has never been greater, and that Dr. Aoyagi’s death has coincided with a reaffirmation of the impact he has had on countless patients across the world.

References

Research Webinars

By Felix Scholkmann.

IMPORTANT NOTE: This post corresponds to the news as it appeared included in the SfNIRS newsletter July 2020 issue, and it is kept for archive purposes. For a confirmed list of webinars, please check the webinars page.

Call for speakers

Starting soon, SfNIRS is organizing monthly SfNIRS Research Webinars giving early career researchers and junior scientists the opportunity to give a talk about their work in the field of fNIRS. For example, you may wish to share a recently published study. Sessions should last around 40 mins (plus 20 min discussion).

If you are interested in giving a talk, please email Felix.Scholkmann@usz.ch

We look forward to hearing your insights.

The SfNIRS Research Webinar Committee:

Felix Scholkmann (chair); Sabrina Brigadoi, Swetha Dravida, Thomas Dresler, Lauren Emberson, Jessica Gemignani, Yoko Hakuno, Kaja Jasinska, John Sunwoo, Sungho Tak

We received already applications to give a talk from:

Name, EmailInstitutionTopic
Jonas FischerICFO-The Institute of Photonic Sciences Mediterranean Technology ParkTalk about the non-invasive estimation of intracranial pressure based on the pulsatile cerebral blood flow measured with DCS and machine learning algorithms. Recently, we have published this in the Journal of Neurotrauma
Sarah RöschUni Leipzig, GermanyfNIRS neurofeedback with patients having binge-eating disorder
Hamoon ZohdiUni Bern, SwitzerlandfNIRS study about color exposures
David RosenbaumUni Tübingen, GermanyfNIRS in psychotherapeutic settings (provocation designs and in situ measurements)
Mario ForcioneUniversity Hospitals Birmingham, UKContrast-enhanced NIRS with Indocyanine Green in acute moderate and severe traumatic brain injury
Satoshi MorimotoJapanfNIRS hyperscanning

Educational Tutorials

By Judit Gervain

The first online Educational Tutorial was held on July 1st, 2020 with an introduction to the basic principles of fNIRS by Hellmuth Obrig. The tutorial was a great success with participants from 14 different countries from 4 continents, Africa, Asia, North America and Europe. Thanks a lot to all the attendees and to Hellmuth for the exciting and very engaging presentation!

The upcoming program of the tutorial series will be posted on the Society’s Facebook page over the coming weeks. The tutorials will cover a wide variety of specific subjects in fNIRS methodology, in an interactive, and whenever relevant, hands-on manner, e.g. for software demos.

The tutorials will be available to the Society’s members. They will be recorded and the videos will be made available as members-only content on the Society’s website.

Research Webinars and Educational Tutorials

By Clare Elwell.

We are setting up online activities to keep our community connected in the absence of face to face meetings.

Felix Scholkmann is chairing our new Research Webinar committee who are planning a regular series of research talks from a broad range of speakers to discuss recent findings and future directions for fNIRS. We are particularly looking forward to hearing from early career researchers in this programme.

The Educational Committee, chaired by Judit Gervain, are developing a syllabus of online Educational Tutorials covering a range of topics and aimed at those wishing to enhance their knowledge in particular technical and application aspects of the technology. To enable interactive content some of these sessions will have a limited number of attendees.

These events will initially be scheduled to take place at 3pm Central Europe (9am Eastern US, 10pm Japan) to try and accommodate different time zones as best we can. With the exception of the first events (which can be thought of as tasters) these events will only be open to SfNIRS members. Our intention is to record the content make it available on the members only section of our website.

SfNIRS Newsletter March 2020

Welcome to the March 2020 issue of the SfNIRS newsletter, which is intended to serve as a save-the-date for October’s fNIRS meeting in Boston, currently scheduled for Oct. 10th through Oct. 14 (https://fnirs2020.org/program/schedule/), and to provide some news about new fNIRS developments.

We are following the development of the Covid19 pandemic and we hope that by October 2020 the world will be back to normal and we will be able to hold our biennial conference as planned. We are continuing with the plan for the meeting, but at the same time, we are preparing to move it to a later date (Autumn 2021?) if deemed necessary. Please register and submit your abstract following current deadlines. Stay safe, take care of your loved ones, and see you in Boston this October. Mari Franceschini.

The communications committee look forward to hearing from you about future news items you’d like to see posted. In the meantime, we’ve got information about job postings, the course component of the SfNIRS 2020 meeting, and an overview of a new wearable device developed by a group at University of St. Andrews in Scotland. Check it out!

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NIRS help to investigate diving physiology in the brain

By Sabrina Brigadoi and Dani Forster.

A novel wearable NIRS device has been developed by a team at University of St Andrews (St Andrews, Scotland) with the aim to investigate diving physiology in the brain and blubber of mammalians (harbor seals). This work has been recently highlighted on the BBC Science Focus Magazine (https://www.sciencefocus.com/news/seals-use-thought-to-prepare-body-for-diving/).

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