A sensitive flow-through microcalorimeter for measuring the heat production of cardiac trabeculae.
Measurement of the energy consumption of isolated cardiac muscle requires a flow-through microcalorimeter with sensitivity in the microW range. In this paper we describe and characterize a sensitive flow-through microcalorimeter, designed and constructed for measuring the heat output of cardiac trabeculae. The device exploits a non-contact, temperature-sensing technique utilizing infra-red-sensitive, thin-film thermopile sensors. The microcalorimeter achieves a sensitivity of 1.8-1.9 V/W at a flow rate of 1 microl/s, with a time constant of approximately 3.5 s. The typical power signal-to-noise ratio is better than 200. Predictions of a finite element model of the calorimeter's characteristics compare favourably with measured data.
Taberner
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A
Department of Mechanical Engineering, MIT, Cambridge, MA, USA.
Kirton
R
R
F Nielsen
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P
Loiselle
D
D
Hunter
I
I