The Heart

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The Heart

• From physiology to ECG measurement and beyond

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Lesson overview

• Introduction to the physiology of the heart
• Activation potential
• Basic anatomy
• ECG
• Devices for ECG measurement

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Electrophysiology of the cardiac muscle cell
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The anatomy of the heart and associated vessels
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The conduction system of the heart
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Propagation of activation front between a pair
of extracellular electrodes
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Electrophysiology of the heart.The different
waveforms for each of the specialized cells found
in the heart are shown. The latency shown
approximates that normally found in the healthy
heart.
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The generation of the ECG signal in the
Einthoven limb leads
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The generation of the ECG signal in the
Einthoven limb leads
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Einthoven, Wilson and Goldbergs precordial leads
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Holter

• Dlouhé záznamy, 24-hodinové, zjednodušený svodový
  systém
• Rozdíly proti standardnímu 12-ti svodovému EKG
• Nevýhody
• Méne kanálu
• Více šumu
• Obtížná detekce P-vlny
• Pohybové artefakty
• Velká dynamika RR-intervalu
• Výhody
• Vetší casový záber
• Lepší detekce arytmií
• Pokrytí bežných lidských cinností

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Holter

• Demonstrace variability signálu pri holterovském
  merení

• Je treba velké robustnosti jak u analýzy signálu
  tak pri diagnostice

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Holter príklad

• Roztrídení (clustering) beatu z holterovského EKG
  záznamu
• Na základe zmerených parametru vypocítán medián
• Cíl Koherentní skupina pro další diagnostiku

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Mapy - príklady usporádání elektrod
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Mapy usporádání elektrod

• 80 elektrod rovnomerne rozložených
• na hrudníku a zádech pacienta (systém
  Cardiag)
• pro predzpracování signálu bylo využito
  nekolikero metod,
• vcetne metody vlnkové transformace
• Na generovaných mapách se dají, stejne jako na
  signálu,
• hledat príznaky

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Okamžikové potenciálové mapy

• základní typ map definovaný
• príklad potenciálové mapy z oblasti QRS komplexu

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Integrálové mapy

• typ map vytvárený podle vztahu
• príklad integrálové mapy z oblasti QRS komplexu

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Isochronní mapy

• typ map vytvárený podle vztahu
• príklad isochronní mapy casu trvání intervalu QT
  

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Rozdílové mapy

• typ map vytvárený podle vztahu
• príklad rozdílové integrální mapy z oblasti QRS
  komplexu

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Mapování 3D inverzní úloha

• Vyhledávání a zobrazení potenciálu srdce na
  samotném epikardu
• Merení provádeno bud prímo v srdci
• Nebo hledání rozložení potenciálu na srdci z
  povrchového rozložení
• Vede na rešení inverzní úlohy
• Hledání ložisek v objemu srdce

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Nové trendy v elektrokardiografii

• Vetší duraz na prevenci
• Vetší možnosti pacienta podílet se na kontrole
  svého zdravotního stavu
• Nové zpusoby merení EKG senzory prímo v
  oblecení
• Nové zpracování na mobilních telefonech
• Telemedicínské aplikace

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Nové trendy v elektrokardiografii
? Sensorické tílko
? Základna
GPRS
Bluetooth
? Mobilní telefon
? PBM
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• An average heart pumps 2.4 ounces (70
  milliliters) per heartbeat. An average heartbeat
  is 72 beats per minute. Therefore an average
  heart pumps 1.3 gallons (5 Liters) per minute. In
  other words it pumps 1,900 gallons (7,200 Liters)
  per day, almost 700,000 gallons (2,628,000
  Liters) per year, or 48 million gallons
  (184,086,000 liters) by the time someone is 70
  years old. That's not bad for a 10 ounce pump!
• For more information on the human heart and
  related topics, check out the links on the next
  page.
• What causes the sound your heart makes?
• When someone listens to your heart with a
  stethoscope the sound is often described as -
  lub-dub lub-dub. The 1st heart sound (lub) is
  caused by the acceleration and deceleration of
  blood and vibration of the heart at the time of
  the closure of the Tricuspid and Mitral Valves.
  The 2nd heart sound (dub) is caused by the same
  acceleration and deceleration of blood and
  vibrations at the time of closure of the Pulmonic
  and Aortic Valves.
• How many times does you heart beat?
• The average heartbeat is 72 times per minute. In
  the course of one day it beats over 100,000
  times. In one year the heart beats almost 38
  million times, and by the time you are 70 years
  old, on average, it beats 2.5 billion times!
• Does your heart rate change as we age?
• Everyone's pulse (average heart rate per minute)
  changes as we age. Here is a chart of average
  pulse at different ages
• Age Pulse
• Newborn 130
• 3 months 140
• 6 months 130
• 1 year 120
• 2 years 115
• 3 years 100

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• The AbioCor, developed by Abiomed, is a very
  sophisticated medical device, but the core
  mechanism of the device is the hydraulic pump
  that shuttles hydraulic fluid from side to side.
  To understand how it works, let's look at the
  various components of the system
• Hydraulic pump - The basic idea with this device
  is similar to the hydraulic pumps used in heavy
  equipment. Force that is applied at one point is
  transmitted to another point using an
  incompressible fluid. A gear inside the pump
  spins at 10,000 revolutions per minute (rpm) to
  create pressure.
• Porting valve - This valve opens and closes to
  let the hydraulic fluid flow from one side of the
  artificial heart to the other. When the fluid
  moves to the right, blood gets pumped to the
  lungs through an artificial ventricle. When the
  fluid moves to the left, blood gets pumped to the
  rest of the body.
• Wireless energy-transfer system - Also called the
  Transcutaneous Energy Transfer (TET), this system
  consists of two coils, one internal and one
  external, that transmit power via magnetic force
  from an external battery across the skin without
  piercing the surface. The internal coil receives
  the power and sends it to the internal battery
  and controller device.
• Internal battery - A rechargeable battery is
  implanted inside the patient's abdomen. This
  gives a patient 30 to 40 minutes to perform
  certain activities, such as showering, while
  disconnected from the main battery pack.
• External battery - This battery is worn on a
  Velcro-belt pack around the patient's waist. Each
  rechargeable battery offers about four to five
  hours of power.
• Controller - This small electronic device is
  implanted in the patient's abdominal wall. It
  monitors and controls the pumping speed of the
  heart.
• The AbioCor heart, which is composed of titanium
  and plastic, connects to four locations
• Right atrium
• Left atrium
• Aorta
• Pulmonary artery
• The entire system weighs about 2 pounds (0.9 kg).
  In the next section, you will learn how surgeons
  implanted the AbioCor heart during a seven-hour
  operation.

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• Until recently, the only option for many severe
  heart failure patients has been heart
  transplants. However, there are only slightly
  more than 2,000 heart transplants performed in
  the United States annually, meaning that tens of
  thousands of people die waiting for a donor
  heart. On July 2, 2001, heart failure patients
  were given new hope as surgeons at Jewish
  Hospital in Louisville, Kentucky, performed the
  first artificial heart transplant in nearly two
  decades. The AbioCor Implantable Replacement
  Heart is the first completely self-contained
  artificial heart and is expected to at least
  double the life expectancy of heart patients.
• In this article, you will get an in-depth look at
  how this new artificial heart works, how it's
  implanted into a patient's chest and who might be
  a candidate for receiving one of these mechanical
  hearts. We will also compare the AbioCor heart to
  the artificial hearts that have failed in the
  past.

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• Heartbeat
• Smaller animals have faster heartbeats. This is
  evident within a species as well, as the young
  beat their hearts faster than the adults. See
  "Early development" above for information about
  the early human heart rates. The Gray Whale's
  heart beats 9 times per minute, Harbour Seal 10
  when diving, 140 when on land, elephant 25, human
  70, sparrow 500, shrew 600, and hummingbird 1,200
  when hovering. An ectothermic animal will usually
  have a slower, and more variable heartbeat than
  an endothermic animal of similar size.

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• he study of diseases of the heart is known as
  cardiology. Important diseases of the heart
  include
• Coronary heart disease is the lack of oxygen
  supply to the heart muscle it can cause severe
  pain and discomfort known as Angina.
• A heart attack occurs when heart muscle cells die
  because blood circulation to a part of the heart
  is interrupted.
• Congestive heart failure is the gradual loss of
  pumping power of the heart.
• Endocarditis and myocarditis are inflammations of
  the heart.
• Cardiac arrhythmia is an irregularity in the
  heartbeat. It is sometimes treated by implanting
  an artificial pacemaker
• Congenital heart defects.
• If a coronary artery is blocked or narrowed, the
  problem spot can be bypassed with coronary artery
  bypass surgery or it can be widened with
  angioplasty.
• Beta blockers are drugs that lower the heart rate
  and blood pressure and reduce the heart's oxygen
  requirements. Nitroglycerin and other compounds
  that give off nitric oxide are used to treat
  heart disease as they cause the dilation of
  coronary vessels.
• At Groote Schuur Hospital in Cape Town, South
  Africa, 53-year-old Louis Washkansky on December
  3, 1967 became the first human to receive a heart
  transplant (however he died 18 days later from
  double pneumonia). The transplant team was headed
  by Christiaan Barnard.

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• The heart (Latin cor) is a hollow, muscular organ
  in vertebrates that pumps blood through the blood
  vessels by repeated, rhythmic contractions, or a
  similar structure in annelids, mollusks, and
  arthropods. The term cardiac means "related to
  the heart", from the Greek kardia (?a?d?a) for
  "heart". The human heart is the most studied
  organ in biology.

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• So the heart is the beginning of life, the Sun of
  the Microcosm, even as the Sun deserves to be
  call'd the heart of the world for it is the
  heart by whose virtue and pulsation the blood is
  moved, perfected, made apt to nourish, and is
  preserved from corruption and coagulation it is
  the household divinity which, discharging its
  function, nourishes, cherishes, quickens the
  whole body, and is indeed the foundation of life,
  the source of all action."

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• http//www.invisionguide.com/heart/flash/index_pro
  .php

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Prehled prezentace

• OBECNÁ CÁST
• Úvod do Biomedicínských signálu
• Vzorkování
• Vzorkování Shanon.
• casová a frekvencní reprezentace signálu
• Filtrace
• Princip
• Príklady
• Analýza EKG
• Rozmerování signálu
• Výber príznaku
• Diagnostika
• Co umožnuje automatická diagnostika
• Príklady
• PRAKTICKÁ CÁST
• 12-ti svodové EKG
• Holter