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Our research project focuses on medical implant for GERD and NERD diagnosis to early detect or prevent esophageal cancers.

Home

Research

 

BESTTM (Batteryless Endoluminal Sensing Telemeter)

for

GERD (GastroEsophageal Reflux Disease)

and

NERD (Nonerosive reflux disease)

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.

 

 

 

 

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.

 

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.

 

 

 

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.

 

 

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.

 

 

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.

 

 

Our team

Professor J.C. Chiao

iMEMS, Electrical Engineering, UT-Arlington

Professor Shou Jiang Tang

Trinity Mother Frances Hospitals and Clinics, The University of Texas Health Science Center at Tyler, Professor Tang

Dr. H. Fred Tibbals

UT-Southwestern Medical School, Bioinstrumentation Center

Professor Stuart Spechler

UT-Southwestern Medical School, Internal Medicine Department, Professor Spechler

 

Our Connections

Professor Don Castell

Medical University of South Carolina, Department of Medicine, Professor Castell

 

Publicity about our GERD Sensors

 

 News home

2007 11 05

Website

UTA front page Mavericks  Front page image

UTA Mavericks feature profiles  Website  Pdf format

2007 11 02

Magazine

UT Arlington 2007 Research Magazine.

Sensing a solution”  Website  pdf format

Research passes media's acid test”  Website  pdf format

“Forwards: Measuring research growth”  Website  pdf format

 

 

 

 

 

 

 

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.  Pdf version  Jpeg version

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.  BEST  BEST webpage  All awards in 2009  All awards in 2009 webpage  Technical Details  Selection Criteria  WT-2009 Announcement  UTA COE frontpage

2009 03 16

News

“New Wireless System Developed to Detect Esophageal Reflux” in Bio-Medicine website.  Website page 1  Website page 2  Print page 1  Print page 2  COE In the News March 9-15

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”  Newsletter

2009 02 25

Press Release

TI Grant Supports Additional Medical Monitoring Research to Dr. Chiao’s group.   Press Release  Pdf format

2008 12 05

Press Release

“UT System funding to spur commercialization of projects”. UTA News Release.  Website page  Pdf format

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”  Website page  Pdf format  Website print page  Website print page PDF format  Newsfordev.” broadcasts the article  UTA Today 080801

2008 06 30

Newspaper

Fort Worth Business News about the Texas Ignition Fund awarded to Dr. Chiao.  Website  Print version in pdf

2008 06 23

Newspaper

Dallas Morning News “Education Notes – Achievers: Texas Ignition Fund”  Website  Print version in pdf  Website in mht format  LexisNexis News  Texas Cable News  Texas Cable News Print in pdf format  WFAA DFW Channel 8  WFAA Channel 8 Print

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” ”  Website  Print version in pdf  UT System Announcement

2008 02 27

Award

Our GERD sensor was chosen Wacky Innovation #9 by the Indian CIO Magazine 2007 Innovation 100 Award in India.  Website  Website_print The saved website does not include the animation link. Here is the original link (may not be valid permanently).  Original URL They even made an animation for us.  Flash_Animation (you will need a FLV player to play this animation). The report however had a few mistakes on facts.

2008 02 06

TV

Columbia, SC, WIS TV, Channel 10 Count ON WIS News reported our GERD sensors “Health Alert: Treating acid reflux disease”,  Website  Website_print  Website PDF  Website_print_PDF  Video_clip

2008 01 20

TV

Texas, Dallas Fort Worth, WFAA TV, ABC, Channel 8 reported our GERD sensors.

2008 01 24

TV

Kentucky, Louisville, WAVE TV, NBC, Channel 3 reported our GERD sensors “Wireless technology helping diagnose stomach disorder”,  Website  Website_print  Website PDF  Website_print_PDF  Video_clip

2008 01 11

TV

North Carolina, Charlotte, WSOC TV, ABC, Channel 9 Eyewitness News, (also WAXN Channel 64), reported our GERD sensors. “Gastroesophageal Reflux”,  Website  Website_print  Website PDF  Website_print_PDF

2007

TV

Voice of America TV and webcast interview (interviewed on Oct. 23). Showtime to be determined.

2007

Promotion

TV

MedStar Television about our GERD sensors featured Thermpon, Dr. Tang, and Dr. Tibbals.  Video clip (2 minute clip, 10Mb size)  Screen capture - Dr. Tibbals  Screen capture - Dr. Tang  Screen capture - Our sensor  Screen capture - Testing

2007 12 31

TV

Illinois, WHOI TV, ABC, Channel 19 reported our GERD sensor: “Wireless Reflux Chip”,  Website, Website PDF

2007 12 26

TV

Wisconsin, WXOW TV, ABC, Channel 19 reported our GERD sensors “Wireless technology helping diagnose stomach disorder”,  Website  Website PDF

2007 12 21

TV

California, Los Angeles, KNBC, NBC Channel 4 Evening News reported our GERD sensor.  Website  Website Print Format  Website PDF format  Website Print Format

2007 10 07

Press release

College of Engineering Press Release about the GERD sensors and Thermpon.   COE Website  pdf format

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.  Scanned image

2007 09 13

News

UTAToday about the GERD sensor reported by CommunicationsDirect.  Email distribution

2007 09 10

News

CommunicationsDirect, Special report: “Wireless Systems Promise Better Medical Diagnoses”.  Website  Website Print format  PDF format  Print copy.

 

2007 08 01

Magazine

Medical Device & Diagnostic Industry MD&DI Magazine article about the GERD sensors.   Website  Website Print format  PDF format  Print copy.

2007 08 01

News

UT-Southwestern Medical School Centertimes “Novel wireless system can detect esophageal reflux”.  Scan copy  Print copy

2007 08 05

Magazine

Detecon.com German Consulting company magazine: SmartMag. “Doctors, Engineers Develop New Wireless System to Detect Esophageal Reflux”.  Page 60 and Cover

2007 07 17

Forum

John Hopkins Pathology Barrett’s Esophagus Discussion Board “Wireless Reflux Detection”.   Website  Print

2007 07 08

News

RFIDNews.org about Dr. Chiao’s presentation at the RFID Tribe.   Website  Print

2007 07 07

News

NewsWireToday (London) about Dr. Chiao’s presentation the RFID Tribe.  Website  Print

2007 07 06

News

ArriveNet “RFID Innovation in Healthcare”.  Website  Print  Website print format  Print website

2007 07 06

News

RFID Digest in Russia. In Russian. About the GERD sensor.   Website  Print

2007 07 03

News

RFID Info China. In Chinese. About the GERD sensor.  Website  Print

2007 07 03

News

56abc.com. In Chinese. About the GERD sensor.  Website  Print

2007 07 03

News

MoreRFID.com Journal. Hong Kong version and China version. In Chinese. About the GERD sensor.  Website  Print

2007 07 01

News

Baker Botts Technology Calendar about Dr. Chiao’s presentation.  Website  Print

2007 06 29

News

Mediligence.com “New Detection System for GERD”  Website  Print  

2007 06 25

Magazine

Service Provider Weekly “New Wireless Monitoring System to Track Esophageal Reflux”. Paper version and online vision (spweekly.com). Page 58.  Page 58  Entire magazine

2007 06 22

News

HealthDay about the GERD sensors. English version  Website  pdf format  print format and Spanish version  Website  pdf format  print format  original website

2007 06 21

News

VirtualMedicalCentre.com and virtualgastrocentre.com “Doctors, Engineers Develop New Wireless System to Detect Esophageal Reflux”.  Website  pdf format

2007 06 20

News

MSN “Wireless System Tracks Esophageal Reflux”.  Website  Print  Print format

2007 06 20

News

CBC News Canadian Press “Wireless System Tracks Esophageal Reflux”.  Website  Page 1  Page 2  Page 3  print format  original website

2007 06 20

News

HealthCentral.com and AcidRefluxConnection.com about the GERD sensors “Wireless System Tracks Esophageal Reflux”.  Website  pdf format  print format  original website

2007 06 20

News

Austin American-Statesman about the GERD sensors.  Website  pdf format  print format  original website

2007 06 20

News

Atlanta Journal-Constitution about the GERD sensors.  Website  pdf format  original website

2007 06 20

News

Acid-reflux-faqs.com “What Is An Acid Reflux?”  Website  pdf format

2007 06 20

News

RefluxIssues.com Health Scott Network “Wireless System Tracks Esophageal Reflux”.  Website  pdf format

2007 06 20

News

NIH (National Institute of Health) MedilinePlus  Website  pdf format

2007 06 20

News

Forbes.com about the GERD sensors.  Website  pdf format  original website

2007 06 11

News

NewMedBlog.info “Implantable RFID Tag to Wirelessly Monitor GERD”.  Website  pdf format

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.

2007 06 05

News

Reflux Treatment website “Wireless Esophageal Reflux Monitor Tested”.  Website  pdf format

2007 06 05

Forum

InformaticsNurse.com forum “Implantable RFID Tag to Wirelessly Monitor GERD”.    Website  pdf format

2007 06 04

News

Med Gadget Internet Journal “Implantable RFID Tag to Wirelessly Monitor GERD”  Website  pdf format  Print format

2007 06 04

News

MediNews (UK) “Implantable RFID Tag to Wirelessly Monitor GERD”.  Website  pdf format

2007 06 03

News

Medical News Today “New Wireless System To Detect Esophageal Reflux, Developed By Doctors And Engineers”.  Website  Print Format  Web Print  Print Pdf Format

2007 06 03

News

Allhealthmedinfo.com: acid-reflux-and-gerd. “New Wireless System To Detect Esophageal Reflux, Developed By Doctors And Engineers“.  Website  pdf format

2007 06 03

News

MediLexicon (UK) “New Wireless System To Detect Esophageal Reflux, Developed By Doctors And Engineers”.  Website  pdf format

2007 06 01

Radio

DFW WBAP Radio AM820, Interview at UTSW about the GERD sensors.  website  3PM News, MP3  4PM News, MP3  5PM News, MP3

2007 06 01

News

More RFID “Doctors, engineers develop new wireless system to detect esophageal reflux”.  Website  pdf format

2007 05 31

News

Topix “RFID Invention to Detect Esophageal Reflux”.  Website  Print

2007 05 31

News

RFID News “RFID Helps Acid Reflux Sufferers”.  Website  Print

2007 05 31

News

News-Medical.net “New Wireless Monitoring System To Track Esophageal Reflux”.  Website

2007 05 31

News

RFID WebBlog “RFID News “RFID Helps Acid Reflux Sufferers”.  Website  Print

2007 05 31

News

RFID Update “RFID Invention to Detect Esophageal Reflux”.  Website  Print

2007 05 30

News

Actonvision. InfoCast. In French. “Nouveau système sans fil pour détecter le reflux oesophagien, développé par des médecins et des ingénieurs”.  Website  Print

2007 05 30

News

ScienceDaily.com “Wireless Esophageal Reflux Monitor Tested”.  Website  Website Print  Print

2007 05 30

News

BrightSurf.com “Doctors, engineers develop new wireless system.”  Website  Print

2007 05 30

News

The Engineer Online “RFID prevents lump in the throat”.  Website  Print format  Print Webpage

2007 05 29

News

ScienceDaily.com “Doctors, Engineers Develop New Wireless System to Detect Esophageal Reflux”.  Website  Website Print  Print

2007 05 29

News

BioSpace.com about the GERD sensor.  Website  pdf format

2007 05 29

News

VMW Virtual Medical Worlds Monthly about the GERD sensor  Website  pdf format

2007 05 29

News

DentalPlans.com about the GERD sensor.  Website  pdf format  Original website

2007 05 28

News

UTSW Center Times Newspaper about the GERD sensor team.  pdf format,  UTSW Website

2007 05 08

Press release

OpenPR.com about the RFID research at UT-Arlington.   PDF format

2007 05 08

Press release

Texas TechPulse about the Dr. Chiao’s presentation.   PDF format

2007 05 08

Press release

Tech FortWorth about the Dr. Chiao’s presentation.   PDF format

2007 04 26

News

UTAToday about the GERD sensors.  UTAToday Website  UTAToday  Email circulation

2007 04 23

Press release

College of Engineering press release about the RFID GERD sensors.  COE Website  pdf format

2007 04 20

News

Shorthorn article about the GERD sensors.  Website  pdf format  Entire issue

2007 04 11

News

TUV (United Kingdom) Product News “RFID system for acid reflux developed by researchers”  Website,  Print

2007 04 10

Magazine

"Researchers Develop RFID System to Monitor Acid Reflux" in the RFID Journal.  Website,  Website article, Website print,  Website article print,  original URL.

 

 

What is GERD?

 

GERD stands for Gastroesophageal Reflux Disease, some just call it heartburn but there is something more ……

 

About GERD

 

 

Resource

Esophagitis

Sternum

Heartburn

 

 

 

GERD .com

Mayo Clinic

GI Care

Medicinenet

National Sleep Foundation

GI .org

Gastro Source

 

 

American College of Gastroenterology

International Foundation for Functional Gastrointestinal Disorders

NIH

NIH Introduction of GERD

 

GI Partners Program

 

Created by J.C. Chiao