METHOD AND RESULTS 3. IN VIVO

•

DISCUSSION

Christoph Fusch, Dpt. Of Pediatrics, McMaster University, Hamilton, Ontario, L8S 4K1, Canada, Phone: +1 (905) 521 2100 ext 75721, E-mail: fusch@mcmaster.ca

METHOD 1, 2: FABRICATION OF SOU/ LAD AND IN VITRO GAS EXCHANGE EXPERIMENTAL

SETUPSOU Body: • Polydimethylsiloxane (PDMS)• Vascular network of micro

channels• Low volume of 0.14mL

• Collect blood samples pre- and post SOU for gas analysis flow rate: 0.5 – 4 mL/min

Gas Permeable Membrane: • Polycarbonate (PC),normal

PDMS, or porous PDMS• Surface area of 14.08cm2

“Lung Assist Device for term and preterm newborns with respiratory failure- Artificial Placenta ”

A. Manan1, N. Rochow2, W. Wu3, G. Fusch2,S. Monkman2, PR. Selvaganapthy3, C. Fusch1,2

1Dpt. of Biomedical Engineering, 2Div. of Neonatology, Dpt. of Pediatric, 3Department of Mechanical Engineering, McMaster University

INTRODUCTION• Respiratory failure still accounts for 5% of neonatal deaths.

Mechanical ventilation is associated with long term complications. Based on the natural in utero placenta, we propose a pump less lung assist device (LAD) with low priming volume, low resistance, and high gas exchange.

OBJECTIVE

ACKNOWLEDGMENT

• CHRP Funding Received• Provisional US Patent is filed, No. 61526288• Rochow et al, 2013. Int J Artif Organs• Wen-I-W et al, 2013. Lab on Chip• C. Fusch holds the Hamilton Health Sciences Foundation

Jack Sinclair Chair in Neonatology at McMaster University

RESULTS 1: IN VITRO GAS EXCHANGE OF SOU

Postnatal: artificial placenta

• Porous PDMS was superior to PC, normal PDMS membranes by demonstrating a1.6x- 2.6x higher O2 and 1.2x- 2.4x higher CO2 exchange rate.

RESULT 2: IN VITRO GAS EXCHANGE OF LAD

• 1. In vitro: Optimize SOU, by testing gas exchange rates of

different membrane.2. In vitro: Evaluate gas exchange rates of LAD.3. In vivo: Assess feasibility of LAD in hypoxic piglet model.

5 10 15 20 30 400

0.0005

0.001

0.0015

0.002

0.0025

0.003O2 Transfer per cm2

Flowrate (mL/min)

O2

Tran

sfer

(mL/

min

/cm

2)

5 10 15 20 30 400

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0.018CO2 Transfer per cm2

Flowrate (mL/min)

CO

2 Tr

ansf

er (m

L/m

in/c

m2)

5 10 15 20 30 400

10

20

30

40

50

60Resistance of bundle

Flow Rate (mL/min)

Res

ista

nce

(mm

Hg)

0 10 20 30 40 50 600

50

100

150

200

250Flow rate vs. Heart Rate

Flow rate (mLmin)

Hea

rt R

ate

0 10 20 30 40 50 600

20

40

60

80

100

120Flowrate vs. Blood Pressure

Flow rate (mL/min)

Blo

od P

ress

ure

• Achieved a maximum flow rate of 57mL/minute• No correlation is observed between flow rate and heart rate/

blood pressure, indicating that no additional stress is imposed on piglet by the LAD.

T=2 sec T=7 sec T=18 sec

• Bundle can successfully support 10% neonatal lung function.

• 20-30% of CO2 is successfully released, and with increasing flow rate results in improved CO2 removal.

Single Oxygenator Unit Lung Assist Device

Newborn piglet 3-4 hours old

• Successfully constructed a low volume LAD.• PDMS membranes was most effective for O2 and CO2

transfer.• In vitro experiments indicate that the LAD can potentially

provide support equivalent to 10% of neonatal lung function.• In vivo experiments indicate that flow rates through device

are tolerated by the cardiovascular system.• Future work: Assess gas exchange performance of LAD in

a hypoxic piglet model, improve biocompatibility, and develop special catheters to improve cannulation time.

membrane

PDMS body

channel

• Porous PDMS have a 2x lower resistance than PC and 1.3x lower resistance than normal PDMS membrane.