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. Our research project focuses on medical implant for GERD and NERD diagnosis
to early detect or prevent esophageal cancers. |
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BESTTM (Batteryless
Endoluminal Sensing Telemeter) for GERD (GastroEsophageal Reflux
Disease) and NERD (Nonerosive reflux disease) |
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An Implantable, Batteryless and Wireless Capsule with
Integrated Impedance and pH Sensors for Detecting the Reflux of Acidic and
Non-Acidic Materials This
work was presented as Poster of Distinction Award, 2009 Digestive Disease Week Meeting, Chicago, May 30-June 4,
2009. |
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Introduction: Conventional
catheter-based esophageal impedance and pH monitoring systems are bulky and uncomfortable.
Implantable sensors like the Bravo capsule may be more acceptable to
patients, but data collection is limited by battery life and the sensor only
detects pH values. We have previously demonstrated a higher detection rate of
reflux episodes with a batteryless wireless impedance sensor capsule as a
complimentary method to pH sensing. In this work, we have integrated both the
impedance and pH sensors in a single implantable capsule, which is also
wireless and batteryless. We have used a variety of liquids with known pH
values to test the fidelity of our capsule. Methods: Our system includes an
implantable transponder that has impedance- and pH-sensing electrodes, and a
wearable, external reader that wirelessly powers the transponder and records the
radio-frequency signals transmitted by the transponder. The impedance and pH
values are encoded into two modulated frequencies. We tested our system by
placing the sensor in beakers containing different liquids with known pH
values, and by attaching the sensor to the esophagus wall of a pig cadaver,
after which those same liquids were flushed through the esophagus. In the pig
experiments, the external reader was placed on the pig’s chest. In both
experiments, impedance/pH values recorded continuously by our capsule were
compared with those recorded discretely by an adjacently-placed Bravo
capsule. Results: In the air, the Bravo
capsule gave no reading while our dual-sensor capsule indicated 9.3 and 22.7
kHz for impedance and pH values as baselines, respectively. In beakers
containing city water, orange juice, Diet Coke, vinegar and buffer solutions
with pH values of 2, 3.8, 5.8, and 11.5, Bravo recorded pH values of 6.6,
4.8, 3.3, 2.2, 1.8, 3.6, 5.7, and no reading (malfunction). Correspondingly,
our dual-sensor capsule recorded frequency shifts of 2.3, 3.8, 2.7, 3.6, 4.4,
4.2, 4.3 and 4.3 kHz for the impedance value changes indicating reflux
episode occurrence, and frequencies of 27.2, 28.1, 28.7, 28.9, 29.5, 28.7,
27.6 and 26.8 kHz for the pH values indicating a near-linear relationship
between frequencies and pH values. Results of the pig experiments agreed with
those of the beaker experiments, except that the frequency shift amounts were
smaller. The impedance sensor picked up every simulated reflux episode and
the pH sensor indicated the pH information of each episode. Conclusions: Our batteryless,
wireless and integrated sensor capsule system can detect acid and nonacid
reflux episodes providing both impedance and pH information simultaneously
for GERD monitoring. |
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An
Implantable, Wireless and Batteryless Impedance Sensor Capsule for Detecting
Acidic and Non-Acidic Reflux This
work was presented at the Research Forum, Oral session, 2008 Digestive Disease Week Meeting, San Diego, May 17-22
2008. |
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Introduction:
Wireless esophageal pH monitoring, in which a radio telemetry pH sensor
(Bravo capsule, Medtronic) is attached to esophageal mucosa, is more
comfortable and acceptable to patients than conventional, catheter-based
esophageal pH monitoring. The wireless system has a limited battery life and
cannot detect the reflux of non-acidic materials, however. Esophageal impedance monitoring can detect
non-acidic reflux, but available systems all are catheter-based. We have
developed an implantable, wireless and batteryless impedance sensor,
comparable in size to the Bravo capsule, that might be used for long-term
monitoring of both acidic and non-acidic reflux. Methods:
Our system includes a transponder with an impedance electrode that is
implanted in esophagus, and an external reader that records the wireless
signals. Communication between the devices occurs via inductive coupling
between coils in the transponder and the reader. The transponder receives
power through its coil, converts impedance variations caused by contact
between refluxed material and the electrode into modulated frequency shifts,
and transmits those signals to the reader. In this system, impedance is
inversely correlated with frequency. We compared readings of our impedance
sensor and a Bravo pH sensor in a number of different test solutions. We also
tested our system in 3 pigs (75 lbs each),
which were sacrificed immediately before the start of the experiments. For the animal studies,
our impedance sensor and the Bravo pH
sensor were tied together and positioned in the distal esophagus, 3cm
proximal to the gastroesophageal junction, using endoscopic guidance. The external reader was placed against the pig’s
skin around the chest. Test solutions were flushed into the esophagus,
and simultaneous impedance and pH signals
were recorded. Results: For water, orange juice, Diet Coke, vinegar and HCL solutions in beakers, the Bravo recorded pH values of 7.05, 3.9, 3.5, 2.25 and 2.05 while our impedance sensor recorded frequencies of 9.49, 10.69, 9.86, 10.51 and 11.07 kHz, respectively. The BRAVO capsule malfunctioned in air and alkaline solutions, while our sensor can detect frequencies of 7.3 and 10.35 kHz respectively. In the pigs, we found a good correlation between the
impedance and pH values of the solutions flushed into the esophagus. Only the
impedance sensor could distinguish water from air, however. Conclusions: Our implantable,
wireless and batteryless impedance sensor can detect acidic solutions in a
manner comparable to the Bravo wireless pH sensor. Unlike the Bravo capsule,
however, our sensor also can detect nonacidic materials such as air and
water. |
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An
Implantable Wireless Impedance Sensor Capable of Distinguishing Air, Water
and Acid in Gastroesophageal Reflux This
work was presented at the 2007 Digestive Disease Week Meeting, Washington DC, May
19-24 2007. |
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Introduction:
Esophageal impedance monitoring is a new technique to detect episodes of
gastroesophageal reflux that are both acidic and non-acidic in nature.
Currently, the impedance electrodes are placed in a catheter to be inserted
transnasally into the patient’s esophagus. The electrodes are connected to an
external electrical module for power supply and data acquisition. The system
configuration is bulky and very uncomfortable for patients during the study
(more than 24 hours) and may limit the clinical utility of the monitoring
technique. A miniature wireless device that does not require tethered
connection is thus preferred for esophageal reflux monitoring. Methods:
Our approach is based on inductive links between two coils. An external coil
forms a resonance circuit with an RF (radio frequency) source worn by the
patient. A small coil with interdigitated electrodes is implantable in the
esophagus to sense the impedance changes. The implant is fabricated on a
flexible substrate to attach onto the esophagus wall. The electrode impedance
changes in the esophagus, caused by fluid passing, vary the mutual
inductances between two coils and can be detected at the external coil
outside the patient’s body. The signal can be detected by either amplitude or
frequency modulation methods. The implant does not require a battery. Results:
The fabricated implantable device has a dimension of 2×2cm2. In
vitro experiments were done at 3cm away from the device. The detected signals
from amplitude modulation at 1.02 MHz were 11.36 mV, 15.04 mV and 29.26 mV
when air, water and simulated stomach acid were on the electrodes,
respectively. The measured signal at 850 kHz for air and acid were 8.349 mV
and 47.66 mV, respectively. Using frequency modulation, the signal changed
from 263 kHz for air to 68.5 kHz for water and 40.5 kHz for acid. The
frequency approach is more immune to misalignment of coils and motion
artifacts of the patient. Conclusions:
An implantable wireless device to detect impedance changes associated with
gastroesophageal reflux was fabricated. The device is capable of
distinguishing the reflux of nonacidic and acidic materials. With the
wireless approach without the need for a battery, the device can be implanted
in patient’s esophagus for a longer time with more comfort. |
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Our
team |
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Professor
J.C. Chiao |
iMEMS,
Electrical Engineering, UT-Arlington |
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Professor
Shou Jiang Tang |
Trinity Mother Frances Hospitals and Clinics, The University
of Texas Health Science Center at Tyler, Professor
Tang |
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Dr.
H. Fred Tibbals |
UT-Southwestern
Medical School, Bioinstrumentation
Center |
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Professor
Stuart Spechler |
UT-Southwestern
Medical School, Internal Medicine Department, Professor
Spechler |
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Our
Connections |
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Professor
Don Castell |
Medical
University of South Carolina, Department of Medicine, Professor
Castell |
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Publicity about our GERD
Sensors |
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2007 11 05 |
Website |
UTA front page Mavericks UTA Mavericks feature
profiles |
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2007 11 02 |
Magazine |
UT Arlington 2007 Research Magazine. “Sensing a solution” “Research passes media's acid test” “Forwards: Measuring research growth” |
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2009 06 02 |
Award |
“An Implantable, Batteryless and
Wireless Capsule with Integrated Impedance and pH Sensors for Detecting the
Reflux of Acidic and Non-Acidic Materials” Poster of Distinction award at the
2009 Digestive Disease Week. June 2 2009. |
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2009 04 18 |
Award |
BESTTM for GERD won Well-Tech Award 2009 in the
Accessibility category. Well-Tech
Award, Technology for Wellness, is held in Milano, Italy April 18-22 2009.
The annual awards are for technical innovation aimed at products that stand
out for their innovation as well as their qualities of sustainability,
accessibility and improvement of the quality of life. |
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2009 03 16 |
News |
“New Wireless System
Developed to Detect Esophageal Reflux” in Bio-Medicine website. |
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2009 03 01 |
Press
Release |
UTA COE Newsletter “TI Grant
Supports Additional Medical Monitoring Research” and “Hall of Achievement
Inductee, Faculty and Staff Honored at Annual Awards Banquet” |
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2009 02 25 |
Press
Release |
TI Grant Supports Additional
Medical Monitoring Research to Dr. Chiao’s group. |
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2008 12 05 |
Press
Release |
“UT System funding to spur
commercialization of projects”. UTA News Release. |
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2008 07 28 |
Website |
The Future of Things, Cancer Research News published an
article about Drs. Chiao and Tang’s GERD sensors “Radio Sensors to Help
Detect Cancer” |
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2008 06 30 |
Newspaper |
Fort Worth Business News
about the Texas Ignition Fund awarded to Dr. Chiao. |
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2008 06 23 |
Newspaper |
Dallas Morning News
“Education Notes – Achievers: Texas Ignition Fund” |
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2008 05 20 |
Press
Release |
COE Press Release about the
Texas Ignition Fund awarded to Dr. Chiao. “UT Arlington Moving Ideas from Laboratories to Marketplace” ” |
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2008 02 27 |
Award |
Our
GERD sensor was chosen Wacky Innovation #9 by the Indian CIO Magazine
2007 Innovation 100 Award in India. |
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2008 02 06 |
TV |
Columbia,
SC, WIS TV, Channel 10 Count ON WIS News reported our GERD sensors “Health Alert:
Treating acid reflux disease”, |
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2008 01 20 |
TV |
Texas, Dallas Fort Worth, WFAA TV,
ABC, Channel 8 reported our GERD
sensors. |
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2008 01 24 |
TV |
Kentucky, Louisville, WAVE TV, NBC, Channel 3 reported our GERD sensors “Wireless technology
helping diagnose stomach disorder”, |
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2008 01 11 |
TV |
North Carolina, Charlotte, WSOC TV, ABC, Channel 9 Eyewitness News, (also WAXN Channel 64), reported our GERD
sensors. “Gastroesophageal Reflux”,
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2007 |
TV |
Voice of America TV and webcast interview (interviewed on Oct. 23). Showtime to be
determined. |
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2007 |
Promotion TV |
MedStar Television about our GERD sensors featured Thermpon, Dr. Tang, and
Dr. Tibbals. |
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2007 12 31 |
TV |
Illinois, WHOI TV,
ABC, Channel 19 reported our GERD
sensor: “Wireless Reflux Chip”, |
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2007 12 26 |
TV |
Wisconsin,
WXOW TV, ABC, Channel 19 reported our GERD sensors “Wireless
technology helping diagnose stomach disorder”, |
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2007 12 21 |
TV |
California, Los Angeles,
KNBC, NBC Channel 4 Evening News reported our GERD sensor. |
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2007 10 07 |
Press release |
College of Engineering Press
Release about the GERD sensors and Thermpon.
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2007 10 01 |
Magazine |
Chinese Journal of Medical
Instrumentation, “Doctor and Engineer invent a new diagnostic method for
GERD. ”, p. 387, Vol. 31, No.5, 2007. |
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2007 09 13 |
News |
UTAToday about the GERD sensor reported by
CommunicationsDirect. |
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2007 09 10 |
News |
CommunicationsDirect, Special report: “Wireless Systems Promise
Better Medical Diagnoses”. |
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2007 08 01 |
Magazine |
Medical Device & Diagnostic Industry MD&DI
Magazine article about the GERD sensors.
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2007 08 01 |
News |
UT-Southwestern Medical School Centertimes “Novel wireless
system can detect esophageal reflux”. |
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2007 08 05 |
Magazine |
Detecon.com German Consulting company magazine: SmartMag.
“Doctors, Engineers
Develop New Wireless System to Detect Esophageal Reflux”. |
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2007 07 17 |
Forum |
John Hopkins Pathology Barrett’s Esophagus Discussion
Board “Wireless Reflux
Detection”. |
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2007 07 08 |
News |
RFIDNews.org about Dr. Chiao’s presentation at the RFID
Tribe. |
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2007 07 07 |
News |
NewsWireToday (London) about
Dr. Chiao’s presentation the RFID Tribe. |
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2007 07 06 |
News |
ArriveNet “RFID Innovation in Healthcare”. |
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2007 07 06 |
News |
RFID Digest in Russia. In
Russian. About the GERD sensor. |
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2007 07 03 |
News |
RFID Info China. In Chinese.
About the GERD sensor. |
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2007 07 03 |
News |
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2007 07 03 |
News |
MoreRFID.com Journal. Hong Kong version and China version.
In Chinese. About the GERD sensor. |
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2007 07 01 |
News |
Baker Botts Technology
Calendar about Dr. Chiao’s presentation. |
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2007 06 29 |
News |
Mediligence.com “New Detection System for GERD” |
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2007 06 25 |
Magazine |
Service Provider Weekly “New
Wireless Monitoring System to Track Esophageal Reflux”. Paper version and
online vision (spweekly.com). Page 58. |
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2007 06 22 |
News |
HealthDay about the GERD
sensors. English version |
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2007 06 21 |
News |
VirtualMedicalCentre.com and
virtualgastrocentre.com “Doctors, Engineers Develop New Wireless System
to Detect Esophageal Reflux”.
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2007 06 20 |
News |
MSN “Wireless
System Tracks Esophageal Reflux”. |
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2007 06 20 |
News |
CBC News Canadian Press “Wireless System Tracks Esophageal Reflux”. |
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2007 06 20 |
News |
HealthCentral.com and
AcidRefluxConnection.com about the GERD sensors “Wireless System Tracks
Esophageal Reflux”. |
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2007 06 20 |
News |
Austin American-Statesman
about the GERD sensors. |
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2007 06 20 |
News |
Atlanta Journal-Constitution
about the GERD sensors. |
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2007 06 20 |
News |
Acid-reflux-faqs.com “What
Is An Acid Reflux?” |
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2007 06 20 |
News |
RefluxIssues.com Health
Scott Network “Wireless System Tracks Esophageal Reflux”. |
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2007 06 20 |
News |
NIH (National Institute of
Health) MedilinePlus |
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2007 06 20 |
News |
Forbes.com about the GERD sensors. |
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2007 06 11 |
News |
NewMedBlog.info “Implantable RFID Tag to Wirelessly Monitor GERD”. |
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2007 06 05 |
TV |
NBC DFW Channel 5
TV News interview about the GERD sensors. The interview was aired at the 5PM
and 10PM evening news. |
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2007 06 05 |
News |
Reflux Treatment website “Wireless
Esophageal Reflux Monitor Tested”. |
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2007 06 05 |
Forum |
InformaticsNurse.com forum “Implantable RFID Tag to Wirelessly Monitor GERD”.
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2007 06 04 |
News |
Med Gadget Internet Journal
“Implantable
RFID Tag to Wirelessly Monitor GERD” |
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2007 06 04 |
News |
MediNews (UK) “Implantable RFID Tag
to Wirelessly Monitor GERD”.
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2007 06 03 |
News |
Medical News Today “New
Wireless System To Detect Esophageal Reflux, Developed By Doctors And
Engineers”. |
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2007 06 03 |
News |
Allhealthmedinfo.com:
acid-reflux-and-gerd. “New Wireless
System To Detect Esophageal Reflux, Developed By Doctors And Engineers“. |
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2007 06 03 |
News |
MediLexicon (UK) “New Wireless
System To Detect Esophageal Reflux, Developed By Doctors And Engineers”. |
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2007 06 01 |
Radio |
DFW WBAP Radio AM820, Interview at UTSW about the GERD
sensors. |
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2007 06 01 |
News |
More RFID “Doctors, engineers develop new wireless system to detect
esophageal reflux”.
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2007 05 31 |
News |
Topix “RFID Invention to
Detect Esophageal Reflux”. |
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2007 05 31 |
News |
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2007 05 31 |
News |
News-Medical.net “New
Wireless Monitoring System To Track Esophageal Reflux”. |
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2007 05 31 |
News |
RFID WebBlog “RFID News “RFID Helps
Acid Reflux Sufferers”. |
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2007 05 31 |
News |
RFID Update “RFID Invention
to Detect Esophageal Reflux”.
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2007 05 30 |
News |
Actonvision. InfoCast.
In French. “Nouveau système sans fil pour
détecter le reflux oesophagien, développé par des médecins et des
ingénieurs”. |
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2007 05 30 |
News |
ScienceDaily.com “Wireless
Esophageal Reflux Monitor Tested”. |
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2007 05 30 |
News |
BrightSurf.com “Doctors, engineers develop new wireless system.” |
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2007 05 30 |
News |
The Engineer Online “RFID prevents lump in the throat”.
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2007 05 29 |
News |
ScienceDaily.com “Doctors,
Engineers Develop New Wireless System to Detect Esophageal Reflux”. |
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2007 05 29 |
News |
BioSpace.com about the GERD
sensor. |
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2007 05 29 |
News |
VMW Virtual Medical Worlds
Monthly about the GERD sensor |
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2007 05 29 |
News |
DentalPlans.com about the
GERD sensor. |
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2007 05 28 |
News |
UTSW Center Times Newspaper
about the GERD sensor team. |
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2007 05 08 |
Press release |
OpenPR.com about the RFID
research at UT-Arlington. |
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2007 05 08 |
Press release |
Texas TechPulse about the
Dr. Chiao’s presentation. |
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2007 05 08 |
Press release |
Tech FortWorth about the Dr.
Chiao’s presentation. |
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2007 04 26 |
News |
UTAToday about the GERD
sensors. |
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2007 04 23 |
Press release |
College of Engineering press
release about the RFID GERD sensors. |
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2007 04 20 |
News |
Shorthorn article about the
GERD sensors. |
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2007 04 11 |
News |
TUV (United Kingdom) Product
News “RFID system for acid reflux developed by researchers” |
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2007 04 10 |
Magazine |
"Researchers
Develop RFID System to Monitor Acid Reflux" in the RFID Journal. |
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GERD stands for
Gastroesophageal Reflux Disease, some just call it heartburn but there is
something more …… |
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Resource |
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GERD .com GI .org |
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American College of Gastroenterology International
Foundation for Functional Gastrointestinal Disorders |
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Created by J.C. Chiao |
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