Rh

ein

Ah

rCam

pu

s R

emag

en ●

Dep

artm

ent

of

Mat

hem

atic

s an

d T

ech

no

log

y

RESULTS Change in Oxygen Saturation DSO2

with respect to baseline: mean ± SD

- NIRO-200NX and moorVMS-NIRS monitors agree within errors

Correlation of Changes in Oxygen Saturation DSO2

for Hamamatsu NIRO200NX and moorVMS-NIRS

High correlation between commercial monitors

for SO2: R2 = 0.99

for DSO2: R2 = 0.97

for tHb: R2 = 0.87

RESULTS

Oxygen Saturation SO2: mean ± SD

- decrease in SO2 with exercise power

- deoxygenation stronger in centre of muscle

- agreement for the two commercial sensors

Normalised total haemoglobin concentration tHb: mean ± SD

- increase in haemoglobin concentration with power

- larger changes in centre of muscle

- within error agreement for two commercial monitors

CONCLUSION

• within errors, haemoglobin

parameters agree for Hamamatsu

NIRO-200 NX and

Moor Instruments moorVMS-NIRS

- high correlation between monitors

for SO2 and DSO2

- correlation for tHb is lower

• Differences between site and / or

left right leg are larger than

between monitors

• Oxygenation changes larger for

centre of muscle compared to

distal site

• Differences might be due to

- positioning / site

- pressure and fixation of sensor

- differences in anatomy / adipose

tissue thickness

- physiology

ANALYSIS OF MUSCLE OXYGENATION PARAMETERS

DURING CYCLING: INFLUENCE OF SITE AND COMPARISON OF DIFFERENT

COMMERCIAL NEAR-INFRARED SYSTEMS

Norman Riedel, Eduard Lukanowski, Arved Reimann, Matthias Kohl-Bareis University of Applied Sciences Koblenz, RheinAhrCampus, Joseph-Rovan-Allee 2, 53424 Remagen, Germany

BACKGROUND • Near-Infrared Spectroscopy (NIRS) is widely used for the analysis of

muscle oxygenation in microcirculation, parameters:haemoglobin

concentration tHb, oxygen saturation SO2 (ref. 1- 6)

• Remaining problems are

- comparison of different monitors which differ in technical details

(wavelength, detectors, algorithm)

- influence of site / muscle group

- there is no gold standard to compare with

AIMS • Comparison of two commercial monitors during incremental cycling

• Analysis of site dependence

• Hypothesis:

- haemoglobin parameters agree for two commercial monitors

- changes in deoxygenation are largest in the centre of the muscle

METHODS • Two commercial NIRS tissue oxygenation monitors

- Hamamatsu NIRO-200 NX:

- Moor Instruments moorVMS-NIRS

- two channels each

- algorithm: spatially-resolved spectroscopy

- oxygen saturation SO2 is main parameter

- as haemoglobin and oxygenation depends on the site

and the sensors have a size of about 5 cm, muscles of

left and right legs were compared

Protocol • n= 11 (healthy, male, age = (22.3 ± 2.7) y, mass = (71.0 ± 8.1) kg,

height = (180 ± 7) cm, adipose tissue thickness = (3.1 ± 2.2) mm) • site: vastus lateralis of left & right leg, central and distal

• cycling, incremental power steps (DP = 30 W, t = 2 min each until Pmax, cadence: 80 cpm)

• descriptive statistical analysis

oxygen saturation

power [Watt]

30 60 90 120 150 180 210 240 270 300 330 360 30

oxyg

en

sa

tura

tio

n S

O2 [%

]

40

50

60

70

moorVMS-NIRS, central

moorVMS-NIRS, distal

Hamamatsu NIRO-200NX, distal

Hamamatsu NIRO-200NX, central

11 11 11 11 11 11 11 9 8 6 3 1 11

Number ofsubjects:

Channel 1 Moor

Channel 2 Moor

Channel 1 Hama

Channel 2 Hama

Correlation of differentiated oxygen saturation between Ch1 Moor & Ch2 Hamamatsu

moorVMS-NIRS DSO2 [%]

-30 -20 -10 0 10

Ha

mam

ats

u N

IRO

-200

NX

DS

O2 [%

]

-30

-20

-10

0

10

DSO2, Hama

= 1.17*DSO2, Moor

- 0.24 %

R2 = 0.97

differentiated oxygen saturation

power [Watt]

30 60 90 120 150 180 210 240 270 300 330 360 30

chan

ge in o

xygen

satu

ration D

SO

2 [%

]

-30

-20

-10

0

10

moorVMS-NIRS. central

Hamamatsu NIRO-200NX, central

11 11 11 11 11 11 11 9 8 6 3 1 11 Number ofsubjects:

normalized total Haemoglobin

power step [Watt]

30 60 90 120 150 180 210 240 270 300 330 360 30

norm

alized tota

l haem

oglo

bin

0.8

1.0

1.2

1.4

1.6

1.8

moorVMS-NIRS, central

moorVMS-NIRS, distal

Hamamatsu NIRO-200NX, distal

Hamamatsu NIRO-200NX, central

11 11 11 11 11 11 11 9 8 6 3 1 11

Number ofsubjects:

REFERENCES

1. Wolf M, Ferrari M, Quaresima V. J Biomed Opt 12,

062104, 2007

2. Bhambhani Y. Can. J. Appl. Physiol. 29, 504-523,

2004

3. Matcher SJ, Kirkpatrick P, Nahid K, Cope M, Delpy

DT. SPIE 1995; 2389: 486–95.

4. Suzuki S, Takasaki S, Ozaki T, Kobayashi Y. SPIE

1999; 3597: 582–92.

5. Geraskin D, Platen P, Franke J, Andre C, Bloch W,

Kohl-Bareis M SPIE 2005; 5859: 58590L.

6. Geraskin D, Boeth H, Kohl-Bareis M. SPIE 2007;

6629: 66281H.

Acknowledgment:

The work was supported by Moor Instruments Ltd.