Exhaled breath analysis holds great promise for
the development of noninvasive, frequently repeatable diagnostic
and monitoring tools. For clinical breath analysis to advance
beyond its current state, however, much closer multidisciplinary
collaboration needs to be not only recognized but also effected.
Therefore, this paper reviews the current state of clinical breath
analysis from the perspective of the challenges the field faces
medically (biomarker uncertainties, sampling methods, dynamics
of exogenous compounds within the body, and standardization),
technologically (the need for an affordable, user-friendly, realtime,
point-of-care instrument for accurate identification of
breath volatiles and their concentrations), biochemically (the
need to link exhaled compounds with specific diseases by understanding
the volatile products particular to relevant pathogenic
processes), and in terms of data interpretation (quality, quantity,
and complexity of data), collaboration (the need for a more
integrated approach to breath analysis, including public health
input), and development from research to accepted clinical use
(funding challenges peculiar to the medical/technological interface,
achieving standards of effectiveness and cost-effectiveness).
Having thus increased awareness and aligned expectations among

  • Response time in seconds at 300 K
  • Reproducible from sensor to sensor
  • Low power: milliWatt /sensor
  • Humidity effect is linear additive
  • Easy integration (2-terminal I/V measurement)
  • Sensor chip size is 1x1cm2 with 12 to 96 channels
  • Non-invasive
  • Low cost
  • Fast and accurate
  • Multi sensors for comprehensive measurement
  • Wired or wireless data transmission over a long distance

The Technology
Cell phone sensor chip
Cell phone sensor chip

Many diseases are accompanied by characteristic odors. Their recognition
can provide diagnostic clues, guide the laboratory evaluation, and affect the
choice of immediate therapy. The study of the chemical composition of
human breath using gas chromatography mass spectrometry (GC/MS)
has shown a correlation between the volatile compounds and the
occurrence of certain illnesses.The presence of those specific
compounds can provide an indication of physiological malfunction
and support the diagnosis of diseases. This condition requires
an analytical tool with very high sensitivity for its measurement. A number
of volatile compounds, so called biomarkers, are found in breath samples,
normally at low parts per billion (ppb) levels. For example, the acetone in the
exhaled breath from human with other biomarkers can indicate
Type I diabetes. Usually, the concentration of
the volatile compounds in human breath is very low and
the background relative humidity is high, almost 100%. NASAs invention utilizes an
array of chemical sensors combined with humidity, temperature, and pressure for
real-time breath measurement to correlate the chemical information
in the breath with the state and functioning of
different human organs. This tool provides a non-invasive method
for fast and accurate diagnosis at the medical point of care or at home.
The sensor chip includes multisensors for a comprehensive measurement of
chemical composition, temperature, humidity, and pressure/flow rate.
The sensor data collected from this chip can be wired or wirelessly transmitted
to a computer terminal at the doctors desk or hospital monitoring center.
The sensor chip can be connected directly or via Universal
serial bus (USB) to a cell phone

relevant disciplines, this paper provides a course of action for
closer collaboration, better understanding, and more productive
dialogue between these disciplines, including an iterative sensor
development process that is integrated with clinical trials, formation
of goals that transcend individual disciplines, creation of
multidisciplinary research teams and a cross-disciplinary student
exchange program, and collaborative funding options.

front image
Nano Sensor Array Chip

  • Detection limit range: ppm to ppb

for data transmission over a long distance and receive an instruction from a doctors
office for an immediate therapy.
Cell phone sensor chip