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ISSN 0301-5491 (P in ), ISSN 2336-5552 (Online)
ORIGINAL RESEARCH
UPGRADE OF THE LANGENDORFF APPARATUS USING
THE INFRARED THERMO-CONTROL SYSTEM
AND AN INTELLIGENT HEATER
Jose Skopalík1,6, Jiří Seko a1, Ma in Pešl2,3,4, Ma ké a Béba o á5, Olga Š eco á5,
Tomáš Pa ák6, V a isla Čmiel1, I o P o azník1, Edi a Jeklo á7, Jose Mašek7
1Depa men o Biomedical Enginee ing, Facul y o Elec ical Enginee ing and Communica ion,
B no Uni e si y o Technology, B no, Czech Republic
2Depa men o Biology, Facul y o Medicine, Masa yk Uni e si y, B no, Czech Republic
3In e na ional Clinical Resea ch Cen e , S . Anne's Uni e si y Hospi al, B no, Czech Republic
4Fi s Depa men o In e nal Medicine – Ca dioangiology Facul y o Medicine, Masa yk Uni e si y,
and S . Anne's Uni e si y Hospi al, B no, Czech Republic
5Depa men o Physiology, Facul y o Medicine, Masa yk Uni e si y, B no, Czech Republic
6Depa men o Pha macology and Toxicology, Facul y o Pha macy, Masa yk Uni e si y, B no,
Czech Republic
7Ve e ina y Resea ch Ins i u e, B no, Czech Republic
Abs ac
Biological expe imen s in ol ing isola ed o gans and issues demand p ecise empe a u e moni o ing and egula ion. An
au oma ic empe a u e con ol sys em was p oposed and op imised on eal isola ed swine hea s and he p o o ype is
desc ibed in his wo k. The adi ional Langendo appa a us consis s o a hea holde , a ese oi o pe usion solu ion
lowing o ao ic cannula and a hea ing ba h allowing passi e hea ans e o he ese oi o pe usion solu ion. The
comme cial in a ed came a FLIR T62101 was added o his basic se -up and used o e y p ecise moni o ing o he
empe a u e kine ic o he o gan and connec ed wi h an elec onic eedback loop, which allowed eal- ime and p ecise
egula ion o hea ans e om he hea ing ba h o he pe usion solu ion and in u n indi ec ly o he hea issue. This
p o ides eal ime con ol and ac i e egula ion o he myoca dial issue empe a u e. The in a ed came a was es ed in
se e al modes and se e al a ian s o de ec ion we e op imised o ideal measu emen o he egion o in e es o he ex
i o o gan. The kine ics o he empe a u e changes and empe a u e s abili y o he issue we e eco ded and calib a ed
by ex e nal elec onic he mome e s ( ype P 100, inse ed in issue). The ime lapse om he hang-up o he hypo e med
o gan (30 °C) un il op imal wa ming (37 °C) was less han eigh minu es in he inal ins umen p o o ype. The inal
s abili y o he 37 °C issue empe a u e was app o ed; he empe a u e luc ua ion o le en icle issue was
cha ac e ised as 36.8 ± 0.5 °C. This upg aded adi ional ins umen could be used in speci ic p eclinical and clinical
ansplan a ion and analy ical p ojec s in u u e.
Keywo ds
isola ed hea , hea pe usion, issue he mos abili y, he mo con olle , IR he mome y
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ORIGINAL RESEARCH
In oduc ion
The use o an isola ed bea ing hea has, o e many
decades, esul ed in undamen al disco e ies ha
imp o ed an unde s anding o he hea ’s physiology
and ca dio ascula medicine [1]. A e og ade-pe used
hea is a me hod ha was imp o ed by Langendo a
he end o he 19 h cen u y [2]. This me hod (scheme on
Fig. 1) is based on he pe usion bu e lowing e o-
g adely down he ascending ao a. The ao ic al e is
closed unde p essu e, and he co ona y a e ies a e
hus illed ia he le and igh co ona y os ia (Fig. 1).
Fig. 1: O e iew o hea pe usion using he
Langendo me hod.
The mos commonly used mode o he Langendo
appa a us is called ‘cons an hyd os a ic p essu e’. The
p essu e is se by he heigh column o he luid ( he
ele a ion o solu ion su ace in a ese oi and hyd o-
s a ic p essu e di e ence o he ip o he cannula in he
ao a).
The ex i o bea ing hea is an excellen model
sys em o obse ing hea physiology o hea elec o-
physiology on he mac oscopic and mic oscopic le el,
he co ona y ascula unc ion and p incipals o
egula ion, and also o simula ing o medical in e -
en ion in p eclinical es s [1, 2]. The pe used hea is
also used o he ex ac ion o single li ing ca dio-
myocy es om a speci ic si e o he hea muscle o
isola ion o issue en i ies, which a e being conside ed
by many biomedical eams [3, 4].
Expe imen s on isola ed hea s demand a p ecise
se ing and con ol o he empe a u e o he hea
issue. Ne e heless, di e ence be ween pe usa e em-
pe a u e and local epica dial empe a u e can be se e al
uni s o Celsius deg ees.
We p esen a echnological concep in ol ing adding
he mosenso s o he adi ional Langendo appa a-
us. This upg aded sys em can be used o p ecise
he mo-con ol o he issue, especially he le en i-
cle. Ou p o o ype was es ed in expe imen s on pig
hea s; howe e , he applica ion could be easily modi-
ied o smalle o bigge isola ed hea s.
Ma e ial and Me hods
Basic design and edesign o he
Langendo appa a us
The basic Langendo se up was modi ied. T adi-
ional componen s (shown in Fig. 2) we e supple-
men ed using a Fo wa d Looking In a ed IR (FLIR)
de ec o came a FLIR-T62101 (FLIR Sys ems, Inc.,
Wilson ille, USA) and compu e connec i i y o he
FLIR came a and he powe supply o hea ing he ba h
(de ails in Fig. 3).
Fig. 2: Componen s o he basic Langendo se up. T1
is empe a u e o he he mos a ba h, T2 is empe a-
u e o he pe usion solu ion nea he en ance o he
ao a.
The compu e was equipped wi h Uni e sal Se ial
Bus (USB e sion 3.1, 10 Gbi /s) designed o high-
speed upload o da a packe s om he FLIR came a.
The u ili y c ea ed on MATLAB pla o m (Ma h-
Wo ks, Na ick, Massachuse s, USA) was able o
iden i y he empe a u e o he le en icle ( he cen al
ield o he hea – 320×256 pixels) and eco d i in he
o m o a da a ma ix in eal ime. The u ili y was se o
compu e he minimal, maximal and mean alue o he
empe a u e poin s on he 320×256 ma ix and com-
mand he powe supply o he hea ing elemen s in he
ba h in eal ime (see Fig. 3 and Fig. 4).
The illus a i e isualisa ion o he da a ma ix (le
en icle) is p esen ed in he o m o a pseudocolou
ame, as shown in Fig. 5. A e ca ying ou a basic
es o unc ionali y wi h espec o he se ing o he
came a and compu ing sys em, h ee impo an
enginee ing asks had o be esol ed: (i) es ing o an
e ec i e ime lap be ween de ec ing he issue
empe a u e (ΔTIR espec i ely) and change in he
empe a u e o he pe usion luids (poin wi h ‘T1
he mome e ’, as shown in Fig. 3); (ii) es ing o he
ime laps be ween de ec ing he issue empe a u e and
su icien compensa ion o empe a u e T2 and he eal
empe a u e o he le en icle; (iii) assessing he
empe a u e measu ed by he IR came a (a compa ison
wi h con ac needle he mome e s).
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ORIGINAL RESEARCH
Fig. 3: Langendo se up modi ied by he IR came a
and compu e o elec onic egula ion o he hea ing
elemen s o he ba h. Au oma ic sc eening o hea
issue is ollowed h ough image p ocessing using
a compu e and he ope a ion o he hea ing elemen s
( espec i ely he pump a e). The eple ion o he
came a scan and commanding o he hea ing elemen
is 1 Hz. Fo each small a ea o 4×4 pixels he a e age
empe a u e TIR and di e ence ΔTIR = 37 - TIR (in
deg ees o Celsius) a e compu ed. The mass o he
es ed expe imen al pig hea was 0.35 kg, he hea
issue was ob ained du ing slaugh e p ocessing o he
pigs.
Fig. 4: The scheme o geome ical a angemen o
componen s: 1 – isola ed hea , 2 – holde and cannula,
3 – he mome e used o he luids in oduced in o he
ao a, 4 – IR came a ( ocused on he le en icle).
Resul s
Time lap be ween he IR came a’s
de ec ion o TLV and eadjus ing T1
The s abili y o he empe a u e o he wa e in he
ba h is he main limi ing ac o o egula ing he speed
o he empe a u e o he pe using solu ion (blood
subs i u e - Ty od solu ion) en e ing he ao a. This
he modynamic ac was immedia ely ob ious a he
beginning o he expe imen . The ba h con ains wo
li es o dis illed wa e , and he hea ing elemen s ha e
maximal ou pu Pmax = 2 kW. We es ed he se e al
p og amming o mulas o commanding he hea ing
elemen s, he op imised so wa e se ing o he
ac i a ion o ou pu P o he hea ing elemen s was
adjus ed o he ollowing o mula:
IF ΔTIR ≥ 3 THEN se P = 1×Pmax
IF 3 ≥ ΔTIR ≥ 0 THEN se P = 0.5×Pmax
This se ing gi es he ollowing ime laps (Table 1)
o s abilising he empe a u e o he ba h ( inal 37 °C).
Table 1: S abilisa ion o T1.
S a ing T
IR
Final T
IR
Time (s)
30 °C
37 °C
138
32 °C
37 °C
69
34 °C
37 °C
35
36 °C
37 °C
8
These ime laps a e su icien o s abilising he
hea issue empe a u e o la ge se o biological
applica ions.
A
B
Fig. 5: Typical ame om he IR came a isualised
by he MATLAB u ili y (A). The co esponding pho o
o he le en icle (B).
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ISSN 0301-5491 (P in ), ISSN 2336-5552 (Online)
ORIGINAL RESEARCH
Quan i ica ion o he ime lap be ween
he IR came a’s de ec ion o TLV and
eadjus ing o T2
The e ec i e ans e o hea om he ba h o he
luids in he p oximi y o he ao a is ano he p oblem.
A p ima y se ing in ol ing ope a ing he hea ele-
men s has been ound o be insu icien o ans e ing
he hea quickly. An ope a ion also had o be ca ied
ou o he pump a e: he pump was upg aded h ough
an elec onical connec ion o he compu e , whe e he
mo o o he pump was ope a ed by his op imised
di ec ion:
IF ΔTIR ≥ 3 THEN se V = 1×Vmax
IF 3 ≥ ΔTIR ≥ 0 THEN se V = 0.5×Vmax
(whe e he maximal ou pu Vmax is he maximal pump
ou pu 0.3 li es pe second; V is he ac ual pump
ou pu ).
This se ing gi es he ollowing ime laps o
s abilising he empe a u e T2 and TIR (Table 2; o his
pu pose measu ed as he a e age empe a u e in he
cen al 2×2 cm o he le en icle).
Table 2: S abilisa ion o T2 and TIR.
S a ing TIR
Time T2 (s)
Time TIR (s)
30 °C
246
382
32 °C 97 199
34 °C
52
85
36 °C
17
32
Assessmen o he accu acy o he
empe a u e measu emen using he IR
came a
The e alua ion o he accu acy o he empe a u e
measu emen using he IR came a can be spli in o wo
s eps. Fi s s ep (calib a ion o FLIR came a sys em
i sel ); he pa ame e s o e lec ance in he IR came a
se up was adjus ed o he mois ened su ace o he skin
model (hea ed body) by a FLIR se ice echnician.
Second s ep (checking o de ec ion alidi y on eal
cada e ); he co ela ion be ween he eal pig issue
empe a u e (cada e p ehea ed in he mos a ic ba h,
con ol needle empe a u e a dep h o 3 mm) and
empe a u e alue om display o IR came a was
checked using. The mome e (P 1000, ype
VOLTCRAFT TPT-206 VC-8603650) connec ed o
Vol age-me e and PC was used (Fig 6A). In o de o
minimize he in luences o he cable esis ance and i s
empe a u e dependan luc ua ions, he 3-wi e ci cui
was used o connec ing o P 100 senso s (Fig 6B).
The hea was imme sed in he ba h o 20 minu es a
empe a u es o 30, 34, 37 o 38 °C in an a emp o
ob ain a uni o m dis ibu ion o he empe a u es ac oss
he issue. The esul s om ou independen measu e-
men s (Table 3) show a high co ela ion o TIR and
Tcon ol.
Fig. 6: (A) Con ol he mome e s a wo poin s o he
issue o compa ison wi h he IR non-con ac came a
measu emen . (B) Scheme o he 3-wi e ci cui o
connec ing o P 100.
Table 3: Co ela ion o he empe a u es (a e age
alue and s anda d de ia ion om 4 expe imen s).
Hea ba h
T
con ol
(°C)
T
IR
(°C)
30 °C
29.9 ±0.6
29.5 ±0.8
34 °C
33.9 ±0.4
33.8 ±0.5
37 °C
37.0 ±0.3
36.8 ±0.5
38 °C
37.9 ±0.4
37.9 ±0.6
The e alua ion o he accu acy o he empe a u e
measu emen on eal issue using he non-con ac IR
came a is e y impo an o all u u e biological
expe imen s. The IR came a was calib a ed ( eadjus ed
o he mois ened su ace o he o gan) by calib a ion
p o ocol o FLIR company. A e ha , he co ela ion
be ween he su ace empe a u e measu ed by he
came a and he empe a u es o he issue (a a dep h o
0–5 mm) was checked using a he mome e P 1000.
The a e age di e ence be ween IR measu ed empe a-
u e and P 100 measu ed empe a u e was de ec ed as
0.2 °C o a ge empe a u e 37 °C.
Discussion
The Oska Langendo model o isola ed hea has
been going h ough nume ous modi ica ions, o e he
decades he concep p o ed i s simplici y and p ac i-
cabili y, e en acing wo king hea sys em [5].
The empe a u e o he hea issue has always been
he key pa ame e [6] and he impo ance has g own
due o u iliza ion o sophis ica ed echniques o
ex ac ion o myocy es, ex ac ion o ex acellula
componen s o in usion o gene-deli e y sys em [7].
Rep oducible esul s o all hese expe imen al me hods
depend on oxygen, nu ien s deli e y, pe usion
p essu e, bu o emos on he s able empe a u e. This
is usually kep by he mocouples wi hin he ba h i sel ,
ne e heless his is applicable only when whole o gan
is subme ged. Ou me hods eplaced adi ional con ac
he mome e by non-con ac IR came a. The selec ion
o he came a was based on knowledge o IR imaging,
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Leka a echnika – Clinician and Technology 2020, ol. 50(4), pp. 137–141, DOI: 10.14311/CTJ.2020.4.03
ISSN 0301-5491 (P in ), ISSN 2336-5552 (Online)
ORIGINAL RESEARCH
which has been used p edominan ly in he e alua ion
o spo s inju ies and he p og ession o he apy o in
disease e alua ion ill oday [8].
The eedback loop in many a ian s o his o ical
Langendo sys ems was ep esen ed by he mos a s
wi h smalle o longe esponse impe ec ion. Ou
me hods eplaced he he mos a s by he so wa e
u ili y commanding he hea ing and ci cula ing sys em.
The inal s abili y o empe a u e in ou p o o ype is
excellen in compa ison wi h some p e ious a ian o
he mocouple sys em [9]. The ocus on he adequa e
a ea o measu ed hea is he impo an aspec o ou
s udy, applica ion o con olled condi ion will allow
p ecise p epa a ion o he hea issue o expe imen al
deli e y, physiological simula ion o ha es ing o
mul iple cell ypes (p ogeni o cells, ca diomyocy es,
e c.), which a e commonly dissocia ed by he mo-
esponsi e enzymes om ex ac ed hea s [10].
Conclusion
Ou p o o ype o he lab sys em based on he
adi ional Langendo appa a us p o ides p ecise
moni o ing and egula ion o he empe a u e o he
isola ed hea . The possibili y o as and p ecise
he mo egula ion o he pe usa e and hea issue
en e ing he ao a was documen ed. The ime lap om
he hang-up o he hypo e med o gan and op imal
wa ming o 37 °C was less han eigh minu es ( he
ini ial empe a u e was 30 °C). The s abili y o he
issue empe a u e was app o ed. Ou aim o u u e
upg ades is o se e an au oma ic sys em wi h con ol
so wa e o ou ine use - iendly applica ions o bo h
clinical and esea ch use.
Acknowledgemen
The wo k has been suppo ed by esea ch g an
MUNIA/A/1255/2018 and suppo ed by he Minis y
o Educa ion, You h and Spo s p ojec “FIT”
(Pha macology, Immuno he apy, nanoToxicology)
CZ.02.1.01/0.0/0.0/15 003/0000495, by he Minis y o
Ag icul u e o he Czech Republic - g an numbe
RO0518, and by he Speci ic Uni e si y Resea ch
p ojec numbe MUNI/A/1307/2019 p o ided by he
Minis y o Educa ion, You h and Spo s o he Czech
Republic.
Re e ences
[1] Bell RM, Mocanu MM, Yellon DM. Re og ade hea
pe usion: he Langendo echnique o isola ed hea
pe usion. Jou nal o molecula and cellula ca diology. 2011
Jun 1;50(6):940–50. DOI: 10.1016/j.yjmcc.2011.02.018
[2] Sk zypiec-Sp ing M, G o hus B, Szeląg A, Schulz R. Isola ed
hea pe usion acco ding o Langendo —s ill iable in he
new millennium. Jou nal o pha macological and oxicological
me hods. 2007 Ma 1;55(2):113–26.
DOI: 10.1016/j. ascn.2006.05.006
[3] Béba o á M, Ma ejo ic P, Pásek M, Simu do a M, Simu da J.
E ec o ajmaline on ac ion po en ial and ionic cu en s in a
en icula myocy es. Gene al physiology and biophysics. 2005
Sep 1;24(3):311.
[4] Skopalík J, Pásek M, Rych a ik M, Ko is ek Z, Gab ielo a E,
Schee P, Klabusay M. Fo ma ion o cell- o-cell connec ion
be ween bone ma ow cells and isola ed a ca diomyocy es in
a cocul i a ion model. Jou nal o Cell Science & The apy. 2014
Jan 1;2014. DOI: 10.4172/2157-7013.1000185
[5] Neely JR, Liebe meis e H, Ba e sby EJ, Mo gan HE. E ec o
p essu e de elopmen on oxygen consump ion by isola ed a
hea . Ame ican Jou nal o Physiology-Legacy Con en . 1967
Ap 1;212(4):804–14. DOI: 10.1152/ajplegacy.1967.212.4.804
[6] Ma in HN. XXI. The di ec in luence o g adual a ia ions o
empe a u e upon he a e o bea o he dog’s hea .
Philosophical T ansac ions o he Royal Socie y o London.
1883 Dec 31(174):663–88. DOI: 10.1098/ s l.1883.0021
[7] Louch WE, Sheehan KA, Wolska BM. Me hods in ca dio-
myocy e isola ion, cul u e, and gene ans e . Jou nal o
molecula and cellula ca diology. 2011 Sep 1;51(3):288–98.
DOI: 10.1016/j.yjmcc.2011.06.012
[8] Kas be ge G, S achl R. In a ed imaging echnology and
biological applica ions. Beha io Resea ch Me hods, Ins u-
men s, & Compu e s. 2003 Aug;35(3):429–39.
DOI: 10.3758/BF03195520
[9] Liao R, Podesse BK, Lim CC. The con inuing e olu ion o
he Langendo and ejec ing mu ine hea : new ad ances in
ca diac pheno yping. Ame ican Jou nal o Physiology-Hea
and Ci cula o y Physiology. 2012 Jul 15;303(2):H156–67.
DOI: 10.1152/ajphea .00333.2012
[10] Pesl M, Jelinko a S, Caluo i G, Holicka M, K ejci J, Nemec P,
Kohu o a A, Zampacho a V, D o ak P, Ro ekl V. Ca dio-
ascula p ogeni o cells and issue plas ici y a e educed in
a myoca dium a ec ed by Becke muscula dys ophy.
O phane jou nal o a e diseases. 2020 Dec;15(1):1–8.
DOI: 10.1186/s13023-019-1257-4
Jose Skopalík, Ph.D.
Dep . o Pha macology and Toxicology
Facul y o Pha macy – Masa yk Uni e si y
Palackého řída 1946/1, CZ 602 00 B no
E-mail: [email protected]
Phone: +420 541 562 890