Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/08—Measuring devices for evaluating the respiratory organs
  • A61B5/097—Devices for facilitating collection of breath or for directing breath into or through measuring devices
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/08—Measuring devices for evaluating the respiratory organs
  • A61B5/082—Evaluation by breath analysis, e.g. determination of the chemical composition of exhaled breath
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/42—Detecting, measuring or recording for evaluating the gastrointestinal, the endocrine or the exocrine systems
  • A61B5/4216—Diagnosing or evaluating gastrointestinal ulcers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
  • A61B2562/02—Details of sensors specially adapted for in-vivo measurements
  • A61B2562/0285—Nanoscale sensors

Definitions

• TITLE DETECTOR AND METHOD FOR DETECTION OF H. PYLORI
• This invention relates to a portable, hand-held, point-of-care medical diagnostic device for the detection of Helicobacter Pylori (H. Pylori) with unlabeled urea and utilizing an ammonia specific and sensitive nanosensor constructed using a polyaniline (PANI) - carbon nanotube composite.
• H. Pylori Helicobacter Pylori
• PANI polyaniline
• H. Pylori a well-known pathogen of the human digestive tract, colonizes the gastrointestinal mucosa at any age, most commonly in childhood. H. Pylori has been associated with significant morbidity and mortality being etiologically linked to peptic ulcer disease, bleeding ulcers, gastric lymphomas (MALTOMAS) and certain forms of gastric cancer. Early diagnosis and eradication of H. Pylori contributes to improved health and prevention of one of the deadliest human cancers. The prevalence of H. Pylori in the developed world is estimated at 25%-55%, depending on demographics, and in the developing world at over 80%, the majority being children.
• H. Pylori Detection of H. Pylori has been accomplished through several diagnostic modalities. These include: a) serum testing for antibodies to H. Pylori; b) gastrointestinal mucosal biopsies for rapid urease testing; c) culture and sensitivity of H. Pylori in tissues obtained through upper gastrointestinal endoscopies; d) stool testing for H. Pylori antigen; and e) Urea Breath Test (UBT).
• Urea Breath Test for the detection of H. Pylori is based on the ability the bacterium possesses to convert urea to ammonia and CC
• UBTs There are two types of FDA approved, commercially-available UBTs based upon the type of urea substrate used: lj C labeled Urea and 14 C labeled urea.
• 14 C is a radioactive isotope of carbon and the 14 C- UBT based on detection of l C0 2 in breath is practically abandoned.
• 13 C is a stable non-radioactive isotope of carbon, encountered in nature and the 13 C-UBT based on the detection of 13 C0 2 in breath is currently the gold standard breath test for the detection of H. Pylori.
• the present invention solves above-mentioned shortcomings by using unlabeled urea as a substrate, by measuring ammonia in breath, instead of CO 2 , and by utilizing an ammonia specific and sensitive nanosensor constructed using a polyaniline (PANI) - carbon nanotube composite.
• PANI polyaniline
• the present invention provides a highly sensitive and specific ammonia sensing device for the detection of H. Pylori which is inexpensive, non-invasive, portable, point-of- care and easy to operate. . » jiviij for gastrointestinal endoscopy to obtain mucosal biopsies and culture for H. Pylori, for stool- testing for the detection of H. Pylori antigen and for the detection of H. Pylori using ⁇ C- Urea Breath Test.
• the present invention comprises an inexpensive, portable, hand held, point-of-care, non- ammonia in breath using a Dolvaniline-carbon nanotube sensor.
• Figure 1 is a block diagram of a detector according to the invention.
• Figure 2 shows the fundamental mechanism for chemical sensing using polyaniline thin films
• Figure 3 shows an image of the sensor in a sensor holder
• Figures 4(a) and (b) show sensor output as a function of pulses of ammonia in dry nitrogen, with Figure 4(a) being a magnification of the circled area (direction of the arrow) of Figure 4(b);
• Figure 5 shows change of resistance of PANI-EB sensor in linear scale on both axes
• Figure 6 shows resistance of the sensor in semi-log scale
• Figure 7 shows sensor output under a pulse of lOppm of ammonia in nitrogen
• Figure 8 shows sensor output under lOppm ammonia in nitrogen in semi-log scale
• Figure 9 shows a graph of how the PANI-EB sensor easily detects ammonia at lOppb level in linear approximation.
• Figure 10 shows electronic circuitry of a device according to the invention. DETAILED DESCRIPTION OF AN EMBODIMENT
• Figure 1 shows a breath-analyzer which consists of mouth piece, trap, emeraldme-base polyaniline (PANI-EB) sensor, N 2 flow, and electronics.
• the electronics comprise an acquisition module, a memory/computation module, and a yes/no display, and a numerical display.
• PANI-EB Emeraldine base polyaniline
• PANI-CSA emeraldine salt form
• Thin films were prepared using the spin casting technique on clean glass substrates with pre- patterned platinum electrodes. Glass substrates were cleaned via sonication in acetone followed by rinsing in deionized water. Polymer films were spin-cast at 1000 RPM for 45 seconds to produce films -100-200 nm thick. A section of the thin films were removed from the Pt finger electrodes to ensure direct electrical contact during measurements by using a combination of Oi/Ar plasma in a March Plasma RIE.
• Figure 3 shows an image of the sensor in the sensor holder.
• the whole substrate is covered with spin-casted PANI film.
• the active area is located in the center of the substrate
• the PANI-CSA thin film samples were characterized by measuring current flow as a function of exposure to ammonia vapors in nitrogen atmosphere at room and elevated temperatures (up to 70°C) at fixed applied voltage. The duration of sensor exposure to ammonia and the concentration of ammonia gas varied.
• FIG. 4(b) shows sensor output as a function of a pulse of ammonia in dry nitrogen of approximately lOppb at 100 seconds and 10 4 ppm at about 250 seconds.
• the initial stage of the sensor response in the circle corresponds to approximately lOppb, as shown in magnification in Figure 4(a), and has a sudden change of characteristic resistance in ohms from the flat baseline to a significant slope. The increase in resistance results in a drop in voltage.
• Figure 5 is a graph showing the change of resistance of the PANI-EB sensor in a linear scale on both axis in response to a pulse of 10 4 ppm of NH 3 in dry N 2 .
• Figure 6 is a graph showing resistance of the sensor in semi-log scale, and shows a two order of magnitude change of the resistance at the application of 10 4 ppm NH 3 in dry N 2 .
• Figure 7 shows a graph of sensor output under a pulse of 10 ppm of ammonia (NH 3 ) in dry nitrogen (N 2 ).
• the analog-to-digital converter (ADC) is shown (proportional to the current in the sensor, where 1 Volt corresponds to 10 U A)-
• the heating of the sensor up to 70°C was introduced for the purpose of recovery of the sensor.
• Figure 8 shows a graph of sensor output under 10 ppm of ammonia ( ⁇ ⁇ , ) in dry nitrogen (N 2 ) in semi-log scale.
• the resistance of the sensor in semi -log scale shows one order of magnitude change of the application of 10 ppm (NH 3 ) in dry (N 2 ).
• Figure 9 shows a graph of how the PANI-EB sensor easily detects ammonia at 10 ppb level.
• the PANI-EB ammonia sensor is an improvement over the M0O 3 ammonia sensor in the Urea Breath Test in the following ways:
• the PANI-EB sensor has higher specificity and sensitivity to ammonia than the M0O 3 sensor.
• the PANI-EB sensor need only be heated to 70°F in order to return to the baseline and be ready to be re-used, while the M0O 3 sensor requires heating at 470°F. Such high heat will create problems for handling a hand-held device.
• the PANI-EB sensor is very easily reproduced as compared to the M0O 3 nanosensor.
• Figure 10 shows the electronic circuitry of the device.
• Figure 10 shows a sensor, interface circuitry and display.
• a micro-controller contains the Analog-to-Digital Converter memory (SRAM), and an Arithmetic Logic Unit (ALU).
• the V test is a voltage proportional to the resistance of the sensor.
• the sensor will detect ammonia gas. If one wishes to detect gases other than ammonia, other sensors could be used. More than one sensor could be incorporated, with a switch to select connection of the sensor to the circuit for the specific gas to be detected.

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• Engineering & Computer Science (AREA)
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• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Pulmonology (AREA)
• Endocrinology (AREA)
• Gastroenterology & Hepatology (AREA)
• Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
• Investigating Or Analysing Biological Materials (AREA)

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• 2012
  • 2012-03-14 EP EP12757987.8A patent/EP2685892A2/de not_active Withdrawn
  • 2012-03-14 KR KR1020137027085A patent/KR20140037828A/ko not_active Withdrawn
  • 2012-03-14 WO PCT/US2012/029103 patent/WO2012125745A2/en not_active Ceased

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