Developing optical measurements of muscle physiology
Submitting Institution
University of EssexUnit of Assessment
Sport and Exercise Sciences, Leisure and TourismSummary Impact Type
TechnologicalResearch Subject Area(s)
Medical and Health Sciences: Clinical Sciences, Neurosciences
Psychology and Cognitive Sciences: Psychology
Summary of the impact
Research at Essex underpinned the development and application of near
infrared muscle oxygen spectroscopy (NIRS) devices that have had medical
and sporting applications in three areas:
1) Research on second derivative spectroscopy underpinned the concept of
the Hutchinson Technology InSpectraTM tissue
spectrometers, and later Essex publications validated the technology. The
current device is used for muscle research worldwide, including in sports
and exercise science. It has US Food and Drug Administration approval and
has been sold for use in many US hospitals with improved clinical outcomes
and economic benefits.
2) Applied research, undertaken at Essex, made first use of the Artinis
Inc. PortamonTM portable NIRS device in elite
athletes (UK short track speed skaters). Subsequently this technology has
been used to assist the training of a number of sports teams including
[text removed for publication] and the Team GB hockey team.
3) This work was also used to engage the public in sports science
research both nationally (e.g. Edinburgh and Cheltenham Science
Festivals 2010-2013) and internationally (Abu Dhabi Science Festival
2011-2013).
Underpinning research
Research at Essex over the last 15-20 years has played a key role in
developing new ways of using light to measure oxygen delivery and
metabolism in human tissue non-invasively. The methods make use of near
infrared spectroscopy (NIRS). This technique uses wavelengths of light —
invisible to the naked eye — that can penetrate deep into tissue. Once in
the tissue, different wavelengths are absorbed by the blood protein
haemoglobin, as well as the cellular proteins myoglobin and mitochondrial
cytochrome c oxidase. Haemoglobin and myoglobin transport oxygen
to the mitochondrion inside the cell, where the cytochrome oxidase
consumes it. These methods of oxygen delivery and utilisation are
responsible for over 95% of the oxygen consumed by the body, and hence the
vast majority of the energy requirements that drive all cellular
processes.
NIRS has been known for over 30 years as a safe and non-invasive means of
reporting on human biology and medicine with widespread potential for
on-going applications in sport and exercise sciences. However, a major
problem with the development of this technology is that near infrared
light is multiply scattered by tissue. This makes it difficult to convert
the amount of light reaching the detector into the quantifiable
concentration of haemoglobin and cytochrome oxidase necessary for
meaningful physiological and biological interpretation of the data.
Research at Essex has used interdisciplinary methods to approach this
problem, combining the complementary expertise of sports scientists,
psychologists, physiologists, clinicians, physicists and biochemists to
develop new methods to analyse and interpret data. Important developments
have been made in both brain and muscle research, but this impact case
study focuses on the muscle work. The key underpinning research at Essex
has been in two areas:
1) The discovery of the use of second derivative spectroscopy of
deoxyhaemoglobin to eliminate artefacts from light scattering in tissue
near infrared spectroscopy (Cooper et al., 1998; Myers et al.,
2005). This method enables absolute concentrations of tissue chromophores
to be determined, in particular deoxyhaemoglobin (the form of haemoglobin
that has released its oxygen to tissue), hence informing on oxygen
extraction. This work was carried out by Professor Chris Cooper (exemplar
publication: Cooper et al., 1998) and the idea was developed by
researchers at Hutchinson Technology Inc. (US). Hutchinson applied the
second derivative technique to a wider wavelength range that also
incorporates the oxyhaemoglobin chromophore. This meant that the ratio of
the oxyhaemoglobin and deoxyhaemoglobin concentration in muscle could be
determined. This ratio is defined as tissue oxygen saturation (StO2) — an
important clinical and biological parameter. The key piece of original
peer-reviewed research that validated this technology was undertaken in
2005 by the company in collaboration with Cooper, who advised on the
details of methodology and analysis (Myers et al., 2005).
2) The application of portable NIRS as a means of measuring real time
muscle oxygen delivery and utilisation that can inform training programs
(see: Hesford et al., 2012; 2013a; 2013b). As part of a 2007 EPSRC
`Achieving Gold in 2012' project grant, medical engineers at UCL and Essex
researchers (biochemists, clinicians, physiologists and coaches) were
funded to: (i) develop a new portable muscle optics device; and (ii)
determine the benefits of such a device as a tool to optimise sports
performance. The Essex team consisted of Cooper (Professor and Project
Lead), Beneke (Professor and co-applicant, now employed as Professor of
Sports Medicine in Marburg, Germany), Angus (Lecturer in Exercise
Physiology, who left Essex in 2011) and Parry (Triathlon coach at the time
of the study, now Lecturer and Human Performance Unit Director at Essex).
The bespoke portable device is still under development at UCL. However,
the sports application ideas developed by the Essex researchers resulted
in a number of sports science publications using a commercial NIRS
spectrometer. Arising from this work, a new collaboration was developed
between Cooper and Dr. Marco Cardinale, at the time Head of Sports Science
and Research at the British Olympic Association. This funded a PhD student
at the University of Essex, Catherine Hesford. The collaboration between
2009-2012 resulted in a series of peer-reviewed publications (see: Hesford
et al., 2012; 2013a; 2013b) using a new commercial portable muscle
spectrometer (Artinis Inc. PortamonTM), which demonstrated
clearly the potential benefits of the use of a NIRS device for monitoring
elite athletes in the field. This research revealed aspects of the muscle
physiology, measured in real time by wireless NIRS, that were challenged
during the extreme stress of short track speed skating. This opened the
possibility of testing for improvements in local muscle oxygen delivery
and utilisation following training and/or nutritional interventions.
References to the research
[can be supplied by HEI on request]
Cooper, C.E., D.T. Delpy and E.M. Nemoto (1998) The relationship of
oxygen delivery to absolute haemoglobin oxygenation and mitochondrial
cytochrome oxidase redox state in the adult brain: a near-infrared
spectroscopy study. Biochem. J. 332, 627-632 (51 citations — Nov
`13) Available at: http://www.biochemj.org/bj/332/0627/3320627.pdf
[Accessed 13 Nov `13]
Myers, D.E., C.E. Cooper, G.J. Beilman, J.D. Mowlem, L.D. Anderson, R.P.
Seifert and J.P. Ortner (2005) Noninvasive method for measuring local
hemoglobin oxygen saturation in tissue using wide gap second derivative
near-infrared spectroscopy. J. Biomed. Opt. 10(3), 034017 (116
citations — Nov `13) DOI:10.1117/1.1925250
Hesford, C.M., S.J. Laing, M. Cardinale and C.E. Cooper (2012) Asymmetry
of quadriceps muscle oxygenation during elite short-track speed skating. Med.
Sci. Sports Exerc. 44, 501-508. DOI:10.1249/MSS.0b013e31822f8942
Hesford, C.M., S.J. Laing, M. Cardinale and C.E. Cooper (2013a) Effect of
race distance on muscle oxygenation in short-track speed skating. Med.
Sci. Sports Exerc. 45, 83-92. DOI:10.1249/MSS.0b013e31826c58dd
Hesford, C.M., S.J. Laing and C.E. Cooper (2013b) Using portable NIRS to
compare arm and leg muscle oxygenation during roller skiing in biathletes:
A case study. Adv. Exp. Med. Biol. 789, 179-184.
DOI:10.1007/978-1-4614-7411-1_25
Research funding:
Cooper, Griffin, Can imaginary exercise be used to control and focus
muscle blood flow changes? Wellcome Trust Showcase Award, 2003-2006,
£125k
Cooper, Beneke, Parry, Non invasive measurements of muscle
oxygenation in elite athletes in the field, EPSRC, 2007-2008, £28k
Cooper, Non-invasive measurement of muscle oxygenation in elite sport,
Olympic Medical Institute, 2008-2011, £46k
Cooper, Quantifying the effects of adipose tissue thickness on muscle
near infrared signals, Artinis Inc., 2012-2013, £125k
Details of the impact
Impacts arising from the manufacture of biomedical equipment:
Cooper's academic research on second derivative spectroscopy (Cooper et
al., 1998; Myers et al., 2005) informed the development of the InspectraTM
StO2 near infrared spectrometers produced by Hutchinson Technology
Inc. A letter of support from Hutchinson [see corroborating source 1]
explains how: "Prof. Cooper's research underpinned the development of
these systems in two ways". Firstly, the letter describes how development
of the devices drew upon Cooper's original research, which showed it was
possible to make an absolute measurement of tissue deoxyhemoglobin
concentration using second derivative optical spectroscopy (Cooper et al.,
1998). The letter details how this research "informed the ideas that led
to [...] Hutchinson's modification of this method to measure absolute
tissue oxygen saturation". Secondly, the letter notes how Cooper's
research also contributed to device validation, outlining how the 2005
collaborative study (Myers et al., 2005) is "widely cited by users of the
StO2 system to justify the use of the device in physiology and medicine".
In the REF2014 impact period, the InspectraTM StO2 series of
NIRS devices has subsequently led to extensive impact in three areas:
Commercial impact: As a global technology manufacturer, Hutchinson
employs 2,000 staff in two divisions. One of these, the BioMeasurement
Division, designs, manufactures and sells a single product type — the
InspectraTM StO2 NIRS system. Over the five-year period
2008-12, the BioMeasurement Division reported net InspectraTM
sales of $9.04M [2] [3].
Clinical impact: The main clinical use of the current technology
has centred on measurements of the thenar (thumb) muscle saturation as an
indicator of peripheral oxygen delivery to tissue. Typical patient groups
include: a) Blood Loss (trauma, post-surgical gastrointestinal bleed); b)
Elderly (clinical signs confounded by medication, co-morbidities,
infection or early sepsis); and c) Critical Care Patients (non-alarming
clinical signs, difficult to diagnose, heart dysfunction). Two devices are
used. Firstly, the InSpectra™ StO2 Spot Check, which is a small
portable device used to quickly and cost-effectively identify patients at
risk for circulatory distress. Once identified to have low StO2 (tissue
oxygen saturation), patients are then continuously monitored with the InSpectraTM
StO2 Monitor. These devices both received 510(k) clearance from the
US Food and Drug Administration in 2011 and 2010 respectively, enabling
them to be legally used in hospital emergency and critical care
environments as cost-effective tools to help rapidly assess tissue
perfusion and shock. There have been over 200 clinical studies on this
technology, many of which cite the original Essex research. Illustrating a
number of significant points, these studies show that, for instance, a low
oxygen saturation can be associated with worse outcomes in critically ill
patients (Lima et al., Crit Care. 2009; 13(Suppl 5):S13). It is
also demonstrated that using saturation to guide patient treatment (Miner
et al., Crit Care Med. 2010; 38(12):S86) can result in significant
economic benefits in the form of shorter hospital stays (down from 11.4 to
8.9 days).
Applied sports impact: Hutchinson spectrometers have been applied
extensively to examine muscle oxygen biology in applied sport and exercise
science. A number of published articles report on such use of Hutchinson
devices. Most notably, these include studies on: muscle oxygenation in
handball players (Int. J. Sports Physiol. Perform. 2008; 3:251-26);
sailors (Int. J. Sports Med. 2008; 29:11-15); high-altitude
climbers (Crit Care. 2009; 13(Suppl 5):S7); and exercise in
patients with symptomatic peripheral arterial disease (Clin Sci (Lond).
2009; 117:405-413) and intermittent claudication (PM&R. 2009;
1:932-940).
Impacts of muscle optics on elite sports performance: The more
applied aspects of Cooper's academic research (see: Hesford et al., 2012;
2013a; 2013b), undertaken in collaboration with the British Olympic
Association (BOA), demonstrated the potential for using real time wireless
portable NIRS to enhance elite sports performance. It revealed asymmetry
in muscle oxygenation due to the nature of the demands of high-speed
cornering constricting blood flow to the right leg in speed skaters. These
research findings were then used to test the efficacy of new equipment and
nutritional supplementation strategies. For example, NIRS research
demonstrated that nitrate-rich beetroot juice would both enhance
performance and reduce the muscle oxygen asymmetry. The Head of Sports
Science and Research at the BOA [4] notes that "this research made an
outstanding contribution to the preparation of our winter sports athletes
for the Winter Olympic Games in Vancouver in 2010 and is making an impact
for the preparation of the Winter Olympic Games in Sochi in 2014...In
particular, the research work improved the understanding of the
physiological demands of speed skating and allowed the coaching team to
develop a new approach to train single limbs with specific technical
drills". He adds that "as a consequence of this work, there has been an
increasing demand in the British sporting community and abroad for the use
of NIRS in athletic populations".
An example of this increasing demand is that Essex was commissioned to
assist in the training of [text removed for publication] and the British
hockey team. [text removed for publication] [5] explains that: "The
technique suggested that our intended training goal of improving oxygen
consumption at the level of the muscle was realised in the majority of the
players tested, helping to inform their future training direction [...]
this project illustrates that the muscle optics research of Professor
Cooper has useful application in the real world elite sporting environment
as a non invasive measure of muscle function". The Senior Strength and
Conditioning Coach of the Great Britain and England Hockey Team states [6]
that: "Chris Cooper's groups at the University of Essex are leading the
way in the use of NIRS and proved invaluable for GB Hockey in a recent
training study [...] the NIRS device proved to be an excellent
non-invasive assessment tool that has helped quantify performance changes
and further our knowledge around oxygen kinetics and adaptation rates in
muscle tissue following a training intervention".
Impacts from public engagement: Significant public engagement
activity has been undertaken by Essex staff, describing their latest
research in muscle NIRS. As well as national and international coverage
via broadcast and print media (including international magazines such as Wired)
sports performance research has been used to engage the public directly.
Most notably this has been at the Edinburgh International Science Festival
(EISF). In 2010, Cooper was involved in developing Blood Bar, a
workshop and show supported in part by a grant from EPSRC. Blood Bar
featured discussions of the colour of blood and its use in health and
sport monitoring, including examples of Essex optics research. Blood Bar
returned to the festival in 2011, 2012 and 2013 and has become one of its
most popular events. The workshop has also toured to Cheltenham Science
Festival (2011) and to the Abu Dhabi Science Festival (2011, 2012 and
2013). In 2011, Cooper organised a live scientific research study adjacent
to the Blood Bar — "Shining Light on Exercise" — looking at the effect of
age and gender on muscle oxygenation during high-intensity exercise
(Wingate Test). Cooper also gave public lectures in 2010 and 2011 as part
of the festival program.
In 2012, EISF staged InMotion, a major interactive exhibition on
the science of human movement, which demonstrated the latest research in
this area. Cooper advised on experiments and provided optics research
equipment for an interactive demonstration on heart rate and oxygen
saturation. InMotion appeared at the National Museum of Scotland in 2012,
toured to Abu Dhabi later that year and then returned to be part of the
2013 EISF. The exhibition will go to the Glasgow Science Centre for six
months starting at Easter 2014, to mark the Commonwealth Games. Details of
all the public engagement activities undertaken by Cooper and others are
included in a letter of support from the Director of the Edinburgh
International Science Festival [7].
Evaluation reports show that the Blood Bar filled to capacity each year
(1,740 children, average age 9.3); the Cheltenham (2,000 visitors) and Abu
Dhabi (2,400 visitors) events had a similar age spread. InMotion had
35,000 visitors at the Museum in 2012, 3,500 at the Ocean Terminal Mall
(Edinburgh) in 2013 and 5,000 in Abu Dhabi [8] [9] [10]. In his letter,
the EISF Director, notes that; "We have had a highly productive
partnership with you and your group over the last four years which has
contributed to some of the most successful events EISF has staged" [7].
Sources to corroborate the impact
[All sources saved on file with HEI, available on request]
[1] Development Manager, BioMeasurement Division, Hutchinson
Technology Incorporated
[2] 10-K; Hutchinson Technology Inc. Annual Report Pursuant to
Section 13 or 15(d) of the Securities Exchange Act of 1934 For the Fiscal
Year Ended September 30, 2012. Available from: http://thomson.mobular.net/thomson/7/3323/4687/document_0/HTCH%202012%2010-K%20-%20reduced.pdf
[Accessed 8 October 2013]
[3] 10-K; Hutchinson Technology Inc. Annual Report Pursuant to
Section 13 or 15(d) of the Securities Exchange Act of 1934 For the Fiscal
Year Ended September 27, 2009. Available from: http://phx.corporate-ir.net/phoenix.zhtml?c=61195&p=irol-reportsannual
[Accessed 8 October 2013]
[4] Head of Sports Science and Research, British Olympic
Association
[5] [text removed for publication]
[6] Senior Strength and Conditioning Coach Great Britain and
England Hockey Team, English Institute of Sport
[7] Director, Edinburgh International Science Festival
[8] Blood Bar Evaluation Report
[9] Blood Bar and InMotion data
[10] Final EISF Evaluation report, May 2012