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 : sales@emka.fr

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: information@bjgyd.com

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: emka@physio-tech.co.jp Physio-Tech website: www.physio-tech.co.jp