Electrogastrography (EGG)

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Electrogastrography (EGG)
The POLYGRAM NET ElectroGastroGraphy Application
is intended to record, store, view and analyze
gastric myoelectrical activity as an aid in the
diagnosis of gastrointestinal motility disorders.
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Electrogastrography (EGG)
EGG is a non-invasive technique that permits
prolonged and repeated recordings of gastric
electrical activity
EGG detects abnormal myoelectrical rhythms,
providing an easy way to define motor
pathophysiology it helps doctors to stratify
patients and improve confidence in their
therapheutic recommendations
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Objective of EGG tests

• To access whether and to what degree electrical
  dysrhytmia of the stomach exist in those patients
  with symptoms suggestive of a gastric motor
  abnormality.
• These symptoms include early satiety after a
  meal, bloating, epigastric pain, nausea and
  vomiting

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Diseases (conditions)

• Gastroparesis
• Functional Dyspepsisa
• Nausea vomitting

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Major Regions of the Stomach

• The Fundus, provides a reservoir for food
  allowing it to be accomodated without an
  excessive increase in intragastric pressure
• The Corpus, where the enzyme pepsin is
  produced. The gastric pacemaker is located at
  the great curvature of the corpus.
• The Antrum, where the hormone Gastrin is
  produced and where mixing and grinding of the
  food takes place
• The Pylorus, is the valve between the stomach
  and the duodenum. It helps controling the
  emptying of the stomach contents into the
  duodenum

Duodenum
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Electrogastrography

• The normal EGG activity is around 3 cpm
• The gastric pacesetter generates an electrical
  signal every 20 sec, that travels towards the
  antrum, and in response to a caloric challenge or
  drug, creates powerful peristaltic contractions
  that force antral contents towards the pylorus
  and assist in grinding and mixing food.

Duodenum
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Myoelectrical activity
In normal humans we see an increase in overall
amplitude after a meal
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Diseases (conditions)

• Gastroparesis (A slight degree of
  gastroparalysis)
• Functional Dyspepsia ( A range of symptoms
  associated with food intake)
• Nausea vomiting

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Clinical applications

• Non-ulcer functional dyspepsia detected by
  gastric dysrhythmia
• Gastroparesis detected by a drop in EGG
  peak power and/or post-prandial decreased
  activity in 3 cpm range
• Monitor efficacy of prokinectic agents
• Assess the risk of post-operative retching and
  complications in laparotomy Nissen Fundoplication

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EGG multi-channel analysis

• Why perform a multi-channel analysis ?
• Detect whether the pacemakers frequency remains
  constant (coupled) or becomes uncoupled as it
  propagates down the stomach.
• Detect whether the power of the signal increases
  as it migrates to the antrum - suggesting normal
  contractility in the stomach after a meal or a
  prokenetic agent

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Improved diagnostic confidence

• EGG can select those patients who will
  respond to prokinetics
• In combination with gastric emptying scintigraphy
  test - which gives motor activity results- we can
  confirm or exclude a gastric motor abnormality
  and identify or exclude a myoelectrical etiology

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Spectrum analysis graph ( EGG)

• Healthy patient
• Increased signal power/amplitude postprandially
• Gastroparesis
• No increased signal in response to a solid meal.
  
• The dominant frequency postprandially is
  abnormal tachy- and/or bradygastria / dysrythmia
  

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Equipment Accessories

• Polygraf ID minimum 8 channels
• EGG main cable
• 1, 3 or 4 ch. extension cable
• Ag/AgCl electrodes
• Skin preparation gel paste
• Motion sensor cable

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Polygraf ID - POLYGRAM NET
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Capture Mode
On line RSA 1 time period
4 EGG channel Real time display
Period markers
Preprandial
Meal
Postprandial
RSA Running Spectrum Analysis
Motion Sensor Channel
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Verify
Preprandial
Meal
Postprandial
Fundus
Corpus
Channel Graph selection display
Tools cut, graph, Go to.
Add Event
Antrum
Pylorus
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Clinical View
Normal Patient
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Brady-Arrhythmia
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Matrix View
Normal Patient
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Unique features (i)

• Integrated impedance check
• Tests impedance in less than 5 sec.
• Step by step on screen guide (skin preparation
  and electrode placement)
• Multi-channel analysis
• Ease of use
• No calibration
• Clinical protocol and report
• POLYGRAM NET software platform
• State of the art analysis algorithms by
  Dr. Chen facilitates short term and long
  term analyses of recorded data

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Unique features (ii)

• Symptom diary
• Windows 2000 operating system
• Real-time on-screen Running Spectrum Analysis
  during capture facilitates easy artifact
  detection and removal

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Customers

• Mainstream gastroenterologists
• Adult gastric emptying specialist
• Pediatric gastroenterologist
• Antireflux surgeons
• GI Physiologists

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Enterra therapy

• Implantable pacemaker for the stomach
• A treatment of chronic nausea and vomiting
  associated with gastroparesis when conventional
  drug therapies are not effective

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Enterra Therapy results..
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Competitors

• 3CPM
• Currently most prominent competitor -
  distribution via Sandhill
• Old system, chunky technology, DOS based, EGG
  only
• MMS
• Up to seven channels
• FFT analysis, DOS based

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FUNCTIONAL DIAGNOSTICS