Biomedical Engineering Reference
In-Depth Information
Fig. 29
Design of a hand portable device
Presently a portable prototype is under construction, which includes a fully
equipped PIMMS within a volume of 4,000 cm³ at a weight of <7 kg (Fig.
29
).
7
Results
The aspects considered for a reliable evaluation of the performance of the miniatur-
ized mass spectrometer are repeatability, resolution, and detection limit. Over the
last years, these parameters could be improved by theoretical analyses and validated
with successive chip generations [
34,
35
] .
The first spectra obtained with the mass spectrometer date back to 2007, where
gas mixtures of Neon, Air and Argon were measured [
23
] . This PIMMS-device was
the first in which the separation principle relied on the new Synchronous Ion Shield
(SIS) Separator, and the first proof-of-principle for the total integration of a mass
spectrometer using batch processes of MEMS technology. Also a quantitative cor-
relation could be stated from the peak heights for different gas concentrations.
Figure
30
displays a spectrum of lab air, neon, and argon. The Ar peak represents
the leakage from the plasma chamber and thus can be used for mass calibration. The
measured resolution
m
/ D
m
at full width at half maximum (FWHM) is 10.8, and 4.3
