RECORDING HUMAN HEMODYNAMICS DURING PARABOLIC …1 3 . 0 8 . 2 0 1 9 1 ICASM 2018 “SHARING THE SKY...
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1 13.08.2019 ICASM 2018 “SHARING THE SKY SAFELY“, Bangkok, 11–15 November 2018 RECORDING HUMAN HEMODYNAMICS DURING PARABOLIC FLIGHTS USING PHOTOPLETHYSMOGRAPHY German Air Force Center of Aerospace Medicine Carla Ledderhos, André Gens, Gerhard Rall and Bernd Johannes
Transcript of RECORDING HUMAN HEMODYNAMICS DURING PARABOLIC …1 3 . 0 8 . 2 0 1 9 1 ICASM 2018 “SHARING THE SKY...
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ICASM 2018 “SHARING THE SKY SAFELY“, Bangkok, 11–15 November 2018
RECORDING HUMAN HEMODYNAMICS
DURING PARABOLIC FLIGHTS
USING PHOTOPLETHYSMOGRAPHY
German Air Force Center of
Aerospace Medicine
Carla Ledderhos, André Gens, Gerhard Rall and Bernd Johannes
VOLANTI SUBVENIMUS
G e r m a n A i r F o r c e C e n t e r o f A e r o s p a c e M e d i c i n e 21 3 . 0 8 . 2 0 1 9
INTRODUCTION
PARABOLIC FLIGHTS
➢ Parabolic flights present one of the fewpossibilities to simulate alternatinggravity conditions under laboratory-type conditions.
➢ The special parabolic trajectory allowsfor approximately 22 seconds of zero-g,preceded and followed by a hyper-gphase.
➢ Parabolic flights are excellent forexamining rapid hemodynamic changesin humans under alternatingaccelerations.
Airbus A300 Zero-G directly before reaching the 0-g phase
Picture: https://bilder.t-nline.de/b/61/32/23/90/id_61322390/610/tid_da/
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INTRODUCTION
IR-LED
R-LED
Skin
Bones
PULSOXIMETRYTakuo Aoyagi, 1972
PHOTOPLETHYSMOGRAPHYHertzmann, 1930s
Photodetector
Pictures and figures: © GAF IAM
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INTRODUCTION
COMPONENTS OF THE PPG SIGNAL
Absorption by venous blood
Absorption by bone and tissue
Time
Absorption
AC Portion
DC Portion
Systolic
Absorptive Maximum
Diastolic
Absorptive Minimum
Figure: © GAF IAM
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INTRODUCTION
QUANTITATIVE EVALUATION OF THE DC PORTIONS OF THE PULSE WAVEDURING CENTRIFUGE PROFILES
All figures: © GAF IAM
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INTRODUCTION
QUANTITATIVE EVALUATION OF THE AC PORTIONS OF THE PULSE WAVE
Am
plitu
de
cha
ng
es I
R P
ort
ion
[%
]
0
100
200
300
400
500
O-AEA
AEA
with PPG
withoutPPG
*
All figures: © GAF IAM
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OBJECTIVES OF THE STUDY
➢ Continuously record the pulse wave duringparabolic flights using photoplethysmography;
➢ derive DC portions (= PPGDC) and AC portions(= PPGAC);
➢ draw conclusions about blood volumedistribution and changes in cardiac contractility.
VOLANTI SUBVENIMUS
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METHODS
SUBJECTS
✓ N = 26
✓ 11 women, 15 men
✓ Age: 33 + 9 years (MW+SD)
✓ valid medical
Picture: © GAF IAM
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METHODS
EXPERIMENTAL PROCEDURE
Phases of parabolic flight
Each subject underwent:
31 parabolas including3 different activity levels:
▪ no load (NL),▪ physical load (PL -50 W),▪ mental load (ML).
20 Seconds20 Seconds 22 Seconds
Microgravity HypergravityHypergravity
1 Minute 10 seconds
Figure: © DLR
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METHODS
DATA ANALYSIS
Gz-Load
PPGAC
PPGDC
A B C D E
Figure: © GAF CAM
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RESULTS
NL ML PLHR [bpm]
PPGDC [AU]
NO LOAD
FLIGHT PHASE
A B C D E
HR
[bpm
]
60
80
100
120
140
160
**
**
NO LOAD
FLIGHT PHASE
A B C D E
PP
GD
C
-150
-100
-50
0
50
100
150*
***
* ***
MENTAL LOAD
FLIGHT PHASE
A B C D E
HR
[bpm
]
60
80
100
120
140
160
*
*
MENTAL LOAD
FLIGHT PHASE
A B C D E
PP
GD
C [
AU
]
-150
-100
-50
0
50
100
150*
*
* ** *
**
PHYSICAL LOAD
FLIGHT PHASE
A B C D E
HR
[bpm
]
60
80
100
120
140
160
PHYSICAL LOAD
FLIGHT PHASE
A B C D EP
PG
DC
[A
U]
-150
-100
-50
0
50
100
150*
**
* ***
* = p<0.05
Figures: © GAF CAM
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NO LOAD
FLIGHT PHASE
A B C D E
PP
GA
C [
AU
]
0
50
100
150
200
250
** *
*
RESULTS
NL ML PLCNAP [mmHg]
PPGAC [AU]
NO LOAD
FLIGHT PHASE
A B C D E
CN
AP
[m
mH
g]
60
80
100
120
140*
**
MENTAL LOAD
FLIGHT PHASE
A B C D E
CN
AP
[m
mH
g]
60
80
100
120
140*
*
**
MENTAL LOAD
FLIGHT PHASE
A B C D E
PP
GA
C [
AU
]
0
50
100
150
200
250*
* *
* *
**
PHYSICAL LOAD
FLIGHT PHASE
A B C D E
CN
AP
[m
mH
g]
60
80
100
120
140*
* *
PHYSICAL LOAD
FLIGHT PHASE
A B C D E
PP
GA
C [
AU
]0
50
100
150
200
250
* = p<0.05
Figures: © GAF CAM
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SUMMARY
➢ The PPG method is an easy-to-use, low-cost methodwithout wearing effects on the test persons.
➢ In flights with alternating accelerations, PPG enablesrelevant information and noninvasive data generation todescribe the instantaneous state of the circulatorysystem.
➢ Our findings confirm that filtered PPG reflects thechanges of blood volume distribution and cardiaccontractility known from earlier studies on parabolicflights using other methodological approaches.
VOLANTI SUBVENIMUS
G e r m a n A i r F o r c e C e n t e r o f A e r o s p a c e M e d i c i n e 1 41 3 . 0 8 . 2 0 1 9
THANK YOU VERY MUCH FOR YOUR ATTENTION!
