Electrocardiogram Measurement and Analysis Equipment: A Tool for Precise Insight into Cardiac Electrophysiological Activity

Electrocardiogram measurement and analysis equipment is an indispensable and important tool in modern medical diagnosis. It can non-invasively and intuitively reflect the heart's electrophysiological activity, providing crucial evidence for the diagnosis, treatment, and prognosis evaluation of cardiovascular diseases. As professional medical devices, they are meticulously designed and fully functional, aiming to provide high-precision, high-reliability ECG data.

I. Equipment Introduction

1. Equipment Overview

Electrocardiogram measurement and analysis equipment is a medical device specifically used to record and interpret the heart's electrophysiological activity. Its core function is to capture the faint bioelectrical signals generated by the heart during contraction and relaxation through surface electrodes, and convert them into graphs (ECG waveforms) and parameters that can be interpreted by doctors. This equipment addresses the limitations of traditional clinical diagnosis, which relied on subjective judgment or invasive examinations for cardiac function assessment. It provides a safe, effective, and highly repeatable method to identify various heart diseases such as arrhythmias, myocardial ischemia, and conduction blocks, serving as a cornerstone for cardiovascular disease screening, diagnosis, and monitoring.

2. Equipment Composition and Working Principle

Electrocardiogram measurement and analysis equipment typically consists of four core components: the main unit, power supply, ECG cables, and ECG electrodes.

• Main Unit: This is the core processing unit of the equipment, integrating the signal input section, amplification circuit, control circuit, display section, recording section, and power section.
  • Signal Input Section: Responsible for receiving raw ECG signals from the electrodes.
  • Amplification Circuit: Amplifies the faint ECG signals to a level that can be processed.
  • Control Circuit: Manages various functions of the equipment, such as gain adjustment, filter settings, and recording mode selection.
  • Display Section: Usually an LCD screen, displaying real-time ECG waveforms, heart rate, and other measurement parameters.
  • Recording Section: Can print ECG reports via a thermal printer, or save digitized ECG data via built-in memory/external storage devices.
  • Power Section: Provides stable power support for the entire equipment, powered by mains electricity or batteries.
• Power Supply: Provides stable and reliable power for the equipment.
• ECG Cables: Connect the ECG electrodes to the main unit, transmitting bioelectrical signals.
• ECG Electrodes: Typically disposable or reusable patch electrodes, directly attached to the patient's body surface to capture the heart's electrical activity.

Working Principle: When ECG electrodes are accurately placed on different parts of the patient's body surface, they can detect the faint electrical potential changes generated by the heart's beating. These electrical signals are transmitted to the main unit via ECG cables. Inside the main unit, the signals first undergo filtering to remove noise such as muscle tremors and power line interference; then they enter the amplification circuit for signal amplification; next, an analog-to-digital converter converts the analog ECG signals into digital signals for computer processing and analysis; finally, these digitized ECG data are processed into clear ECG waveforms, displayed in real-time on the screen, and can be recorded for subsequent measurement and analysis by doctors.

3. Equipment Function Introduction

Electrocardiogram measurement and analysis equipment has multiple key functions to meet the needs of clinical diagnosis and research:

• ECG Signal Measurement and Acquisition: Capable of precisely capturing and digitally storing multi-lead ECG signals, including standard 12-lead, high-resolution ECG, etc.
• Real-time Display and Recording: Real-time display of ECG waveforms on the screen, supporting various recording modes such as automatic recording, manual recording, timed recording, etc., and capable of printing high-quality ECG reports.
• Automatic Measurement and Analysis of ECG Parameters: Automatically measures key parameters such as heart rate, PR interval, QRS complex width, QT interval, ST segment deviation, and provides preliminary analysis reports to assist doctors in diagnosis.
• PR Interval ECG Activity Measurement and Analysis: Specifically for fine measurement and analysis of atrioventricular conduction function, which is of great significance for evaluating the conduction status of the AV node and His bundle.
• His Bundle Electrogram (HBE) Acquisition and Parameter Analysis: Capable of acquiring the electrical activity of the heart's His bundle through specific electrodes and processing techniques, providing deeper electrophysiological information for diagnosing complex atrioventricular blocks, pre-excitation syndromes, and other arrhythmias.
• Data Management and Transmission: Usually equipped with storage function, capable of saving a large amount of patient ECG data, and connecting with hospital information systems (HIS/PACS) via interfaces such as USB, network, etc., to achieve data transmission, sharing, and remote diagnosis.

II. Scope of Application

1. Application Scenarios

Electrocardiogram measurement and analysis equipment is widely used in medical practice, covering multiple scenarios from primary care to high-end specialties:

• Hospital Departments: Widely used in cardiology, emergency departments, intensive care units (ICU), operating rooms, anesthesiology departments, physical examination centers, geriatrics, etc.
• Outpatient and Community Healthcare: Used for routine cardiovascular disease screening, diagnosis, and follow-up examinations.
• Emergency Scene: Portable ECG machines play a key role in pre-hospital emergency care, quickly assessing the patient's cardiac condition.
• Home Health Management: Some small, portable devices can be used by patients for self-monitoring at home, and data can be uploaded to doctors.
• Research and Teaching: Used for cardiovascular physiology research and medical teaching demonstrations.

2. Applicable Diseases and Symptoms

This equipment is primarily used for diagnosing and monitoring a range of diseases and symptoms caused by abnormal cardiac electrical activity:

• Arrhythmias: Such as atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular tachycardia, premature beats (extrasystoles), sick sinus syndrome, various conduction blocks (e.g., atrioventricular block, bundle branch block), etc.
• Myocardial Ischemia/Infarction: Diagnosing myocardial ischemia or acute myocardial infarction through changes in the ST segment, T wave, and Q wave.
• Cardiomyopathy: Such as ECG changes caused by hypertrophic cardiomyopathy, dilated cardiomyopathy, etc.
• Pericarditis, Myocarditis: Specific ECG changes caused by these conditions.
• Electrolyte Imbalance: Such as the effects of hyperkalemia, hypokalemia, hypercalcemia, etc., on the ECG.
• Drug Effects: Assessing the effects and toxic reactions of certain drugs (e.g., antiarrhythmic drugs, digitalis preparations) on cardiac electrical activity.
• His Bundle Electrogram (HBE) is mainly used for:
  • Determining the location of atrioventricular block (intranodal, infranodal, or distal His bundle).
  • Diagnosing pre-excitation syndrome and accessory pathway conduction.
  • Evaluating the electrophysiological mechanisms of tachycardia.
• Related Symptoms: Applicable to patients experiencing symptoms such as chest tightness, palpitations, precordial pain, dizziness, syncope, dyspnea, and fatigue.

3. Contraindications

Electrocardiogram measurement and analysis equipment generally has no absolute contraindications, but caution or special handling is required in the following situations:

• Individuals with Compromised Skin Integrity: For those with open wounds, dermatitis, infection, or severe skin allergies at the electrode placement site, avoid placing electrodes there to prevent worsening injury or causing infection.
• Individuals Allergic to Electrode Materials: Special materials for electrodes or protective measures should be chosen.
• Individuals with Implanted Cardiac Pacemakers, Defibrillators, or Other Electronic Devices: Although modern ECG machines usually have anti-interference capabilities, in some cases, these implants may cause artifacts or interference with ECG signals. Operation should be performed by professional medical staff, and interpretation should be done carefully.
• Patients with Severe Coagulation Disorders or Receiving Anticoagulant Therapy: Electrodes should be removed gently to avoid local skin bleeding or bruising due to tearing.
• Extremely Agitated or Uncooperative Patients: May lead to excessive ECG artifacts, affecting interpretation. Sedation may be necessary if required.

III. Usage Guidelines and Precautions

1. Usage or Operation Method/Steps

Correct and standardized operation is the basis for ensuring the accuracy and safety of ECG measurements:

1. Preparation Phase:
   • Equipment Check: Ensure the equipment has sufficient power, cables are undamaged, and electrode patches are within their validity period and sufficient in quantity.
   • Patient Preparation: Inform the patient about the purpose and process of the examination to help them relax. Expose the chest and limbs, clean the skin at the electrode placement sites, shave hair if necessary, and wipe with alcohol swabs to remove grease and dead skin, improving conductivity.
2. Electrode Placement:
   • Accurately place limb leads (R, L, F, N) and chest leads (V1-V6) electrode patches according to standard 12-lead (or desired lead) placement positions. Ensure electrodes are in firm contact with the skin and free of air bubbles.
3. Cable Connection:
   • Correctly connect each lead wire of the ECG cable to the corresponding electrode patch, and ensure a secure connection to the main unit.
4. Start Measurement:
   • Turn on the equipment, select appropriate gain and filter settings.
   • Confirm that the ECG waveform is clear, the baseline is stable, and there is no significant interference.
   • Instruct the patient to remain quiet, avoid moving, talking, or deep breathing to prevent artifacts.
   • Select automatic or manual recording mode as needed, and begin acquiring and recording ECG signals.
   • If PR interval analysis or His bundle electrogram acquisition is required, more specialized settings and operations are needed according to the equipment manual, usually performed by electrophysiology professionals.
5. Data Processing:
   • After recording is complete, the equipment will automatically analyze and display ECG parameters.
   • Print the ECG report and save raw data or reports to storage media.
6. End Examination:
   • Turn off the equipment, carefully remove electrode patches, and clean the patient's skin.
   • Clean and organize the equipment for next use.

2. Common Error Reminders

To ensure the accuracy and safety of ECG measurements, operators must be vigilant and avoid the following common errors:

• Improper Electrode Placement: Incorrect electrode positions can lead to distorted ECG waveforms, affecting diagnosis. Always follow standard electrode placement guidelines.
• Insufficient Skin Preparation: Skin grease, sweat, or hair can increase skin resistance, leading to poor electrode contact, baseline drift, low-amplitude waveforms, or artifacts. Thoroughly clean and prepare the skin.
• Loose or Damaged Cable Connections: Loose connections or internal cable breaks can cause signal interruption, interference, or no waveform in a particular lead. Cables should be checked regularly.
• Environmental Electromagnetic Interference: Electromagnetic fields generated by surrounding power lines, mobile phones, fluorescent lights, or other medical equipment can introduce noise, leading to a thick ECG baseline or power line interference. Examinations should be performed in an interference-free environment as much as possible.
• Patient Movement or Muscle Tremors: Muscle tremors caused by patient tension, cold, or discomfort can produce motion artifacts, making the ECG difficult to interpret. The patient should be comforted and ensured to be relaxed.
• Uncalibrated or Unmaintained Equipment: Equipment that has not been calibrated or maintained for a long time may lead to inaccurate measurement data. Calibration and maintenance should be performed regularly according to manufacturer recommendations.
• Ignoring Alarm Messages: The equipment may issue alarms for electrode detachment, abnormal heart rate, etc. Operators should pay attention and address them promptly.
• Non-professionals Interpreting Results: The final diagnosis of an ECG requires a doctor with professional knowledge and experience; do not interpret or guide treatment yourself.
• Non-standard His Bundle Electrogram Operation: His bundle electrogram acquisition usually involves invasive procedures and must be performed by experienced electrophysiologists in a professional environment such as a catheterization laboratory, strictly following aseptic operating procedures.