noninvasive blood pressure measurement
noninvasive blood pressure measurement
OPT oscillometric pressure telemetry
a novel way to measure non-invasive blood pressure in freely moving dogs
based on well proven oscillometric cuff method
implemented by miniaturized hardware components suitable for telemetry
analyzed using proprietary detection algorithm
emkaPACK with ecg electrodes and OPT cuff
the OPT add-on fits within the standard emkaPACK transmitter case
the pump and other electronic components run on the same AA batteries used for standard emkaPACK transmitter
tail is shaved
cuff is wrapped around the tail and connected to the transmitter
a custom velcro extension protects the cuff, and maintains it in the proper position on the tail
setting up the animal
runs in user programmed series of cycles
during one cycle
cuff pressure rises rapidly to fully inflate the cuff
cuff pressure is slowly released
how does it work?
OPT train programming graph
20 mn of cuff pressure signal with 5 inflation cycles
close up of inflation cycle
the dog will not tolerate a cuff on its tail
the system has been used for 1000 hours on more than 40 dogs from multiple colonies
the cuff was never chewed off
connecting tubes from the cuff to the transmitter were chewed off 3 times: improvements in the protective cloth prevented recurrence
frequently heard objections
the dog startles and wakes up at each inflation cycle
some dogs may startle the first couple of times the system inflates but all acclimate in a matter of minutes
numerous video recordings prove that dogs, either awake or asleep, do not react when cuff inflates
frequently heard objections
still shots from video recordings
dog movement with its effect on ecg is clearly visible on the activity trace cuff inflation triggers no reaction from the dog
ecg, activity, cuff pressure traces
cuff inflation cycle triggers no reaction from sleeping dogecg, activity, cuff pressure traces
measurements are lost whenever the dog moves
yes, if a dog is very agitated or vigorously wags its tail, there are losses in signal quality
however
marked agitation only occurs a small percentage of the time during a 24 hour acquisition
the analysis algorithm automatically discards cycles too noisy to provide reliable analysis
spurious results are automatically invalidated
frequently heard objections
this measurement method is unreliable!
OPT provides reliable results under stable conditions and detects changes when they occur
potential users say that they are aware of potential limitations but that obtaining this measurement would be of great value
frequently heard objections
mean blood pressure and heart rate from a conscious freely moving dog (20 hour acquisition; each data point
corresponds to one inflation cycle)
detects inflation cycles
applies hi-pass filter
selects valid blood pressure pulses
produces bell shaped amplitude curve
computes mean, systolic and diastolic pressure values
how is analysis performed?
signal is not always as clean as on previous picture
when signal is noisy the algorithm picks pulses that correspond to blood pressure beats and ignores artefacts
for greater efficiency, the software applies a number of criteria and rejects unreliable or spurious results
what are the challenges to produce a reliable analysis?
when things get rough… as on second picture, software ignores pulses from noisy zone
present experience (around 1000 hours of data from 60 dogs) indicate that from 70 to 95% of inflation cycles produce reliable data
what level of analysis can be obtained?
why is analysis able to provide reliable results?
we use innovative processing methods to automatically reject data which does not correspond to heart beat pressure pulses
user is able to review and edit beat by beat data
4 dogs 12 hour acquisitionone OPT measurement every 5 minutesprazosin administration at t=0 by gavage (0.1mg/kg)
comparison with data from DSITM implant
this study as well as numerous preliminary trials of the system, were performed at CIT, a CRO in the Paris area
results of a comparative test study
DSITM data
recorded through openArt and Notocord HEManalyzed with HEMdata reduction with Excel macros from CIT
emka TECHNOLOGIES data
recorded with emka TECHNOLOGIES’ ioxanalyzed with nibp module from emka TECHNOLOGIES’ ecgAUTOdata reduction with emka TECHNOLOGIES’ datanalyst at
equivalent points
results of a comparative test study
results of a comparative test studysystolic, mean and diastolic blood pressure following vehicle treatment (N = 4): circles = emka TECHNOLOGIES OPT, squares = DSITM)
systolic, mean and diastolic blood pressure following Prazosin treatment (N = 4): circles = emka TECHNOLOGIES OPT, squares = DSITM)
results of a comparative test study
systolic, mean and diastolic blood pressure following vehicle treatment (N = 4): circles = emka TECHNOLOGIES OPT, squares = DSITM)
results of a comparative test study
systolic, mean and diastolic blood pressure following Prazosin treatment (N = 4): circles = emka TECHNOLOGIES OPT, squares = DSITM)
results of a comparative test study
data was acquired for 20 hours on a monkey
the animal had not been acclimated prior to the recording
the animal tolerated the cuff
some extra protection was applied to the cuff
pulse amplitude was smaller than from the dog
data analysis produced pressure data consistent with other parameters, including heart rate and activity
test on cynomolgus monkey
systolic and mean blood pressure, HR and pulse transit time(12 out of 400 data points were manually removed as spurious data)
test on cynomolgus monkey courtesy INA Reasearch, Japan
cuff pressure cycle and XY plot of individual blood pressure pulses
test on cynomolgus monkey
20mn average of mean pressure from NIBP recording protocol with Prazosin treatment mark beat by beat mean pressure from vap (color density display)
parallel measurement on dog with NIBP & VAP (vascular access port) courtesy of Zhejiang Univ., China
OPT acquires pressure on freely moving animals
users see recorded data as well as how data is processed and analyzed - this is available on-line and in post-processing mode
users may edit analysis results, and discard outliers
OPT is the only system specifically tailored to safety pharmacology and toxicology needs
OPT may, of course, also acquire data from restrained animals
why do we think OPT is superior to previous systems?
designed for the specific needs of snapshot measurements on restrained animals
uses the same technology, data format, and software as ambulatory OPT
measures:
NIBP1 to 7 lead ecg
provides a seamless solution for safety pharmacology and toxicology
available in summer 2010
OPT snapshot
OPT is the only noninvasive blood pressure measurement for ambulatory animals
has proven its validity through initial trials & test studies
is a viable complement to implantable telemetry
has very low recurring costs is available as an optional add-on to the fully validated emkaPACK product line
is specifically designed for safety and tox studies
visit our websites for complete product descriptions, case studies, a knowledge base, & frequently asked questions:
www.emka.fr
&
telemetry.emka.fr
website
contact us!
please contact us to see how we can help you meet your telemetry research goals!whatever the scale and complexity of your project, please contact us for a professional, competitively priced solutions adapted to your needs
emka TECHNOLOGIES S.A. 59, bd. général Martial Valin - 75015 Paris - FRANCE phone: +33 (0)1 40 60 76 00 fax: +33 (0)1 40 60 65 66
sales and support office for North America:
emka TECHNOLOGIES Inc. 307 Annandale Road, suite 203 Falls Church, VA 22042 - USAphone: +1 (703) 237-9001 fax: +1 (703) 237-9006
for all inquiries contact : [email protected]
distributor for China:
Beijing GuangYuanDa Science and Technology Co. Ltd. Suite 305 Hongchen Business Center,No 20 ZhongFangLi, Chaoyang District, Beijing 100020 phone: +86-10-65019453 fax: +86-10-65019453 contact: [email protected]
distributor for Japan:
Physio-Tech Co., Ltd 6-3, Iwamoto Cho 1-Chome Chiyoda-Ku, Tokyo 101-0032 +81 3 3864 2781 +81 3 3864 2787 contact: [email protected] Physio-Tech website: www.physio-tech.co.jp