Electric Current Effects on the Human Body

Posted on Feb 12, 2025 in Marketing and Commercial Management

Physiological Phenomena Caused by Electric Current

From 1 to 3 mA: perception. Sensitivity or threshold of 10 to 15 mA: tetanization or contraction of the muscles of the hand and arm, close to 25 mA extends to the thoracic muscles. A box from 50 mA: Atrial heart. What Happens to Time Above and Below 150 ms? For times below 150 ms, no risk, if the intensity does not exceed 300 times higher mA. For 150 ms, no risk, if the intensity does not exceed 30 mA. Sequence of the Effects on the Body Produced by the Current

  • Difficulty breathing
  • Ventricular fibrillation cardiac arrest
  • Respiratory inhibition
  • Irreversible nerve damage
  • Severe burns
  • Loss of consciousness
  • Death

What Current Alternating Continuous and Takes to Be a Shock and a Painful Muscle Contraction?

Painful Shock (Alternate: 9 mA) and (Continue? 62 mA) Muscle contraction: (Alternate: 23 mA) and (continuing? 90 mA) Defines the Threshold of Perception

It is called the value of the electric current that a person can withstand, if hands when secured with an electrode voltage suffers a tingling sensation, not unpleasant or muscle pain. The UNE 20-572-92 / 1 sets this value to 0.5 mA. Whatever the time of exposure. Cardiac Cycle

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Current Limit Control Muscular

The muscle control threshold current is defined as the maximum intensity that a person can withstand, besides being able to release the electrode. In alternating current, this value is 16 mA dc, 76 mA. Ventricular Fibrillation

Ventricular fibrillation is an independent action of the cardiac muscle fibers resulting in an uncoordinated contraction and involves the immediate elimination of the physiological activity heart. Since it can not circulate oxygenated blood, and therefore can not make it to the brain, there are few serious injuries cerebrobulbares minutos. The VF is a condition practically irreversible and leads in about 5 or 10 minutes to termination of the cardiac movements. When Fibrillation Occurs?

When the shock lasts less than 0.1 sec. The VF can occur for intensity values greater than 500 mA., And occurs frequently for the current intensity of the order of one ampere if the collision occurs during the vulnerable period. For a collision with a current of 500 mA and more than one cardiac cycle, it can cause irreversible cardiac arrest.

Fibrillation Threshold Values

For short periods of exposure (between 10 and 100 ms), the high threshold is placed in a line from the 500 mA to 400 mA. For durations than one second lower threshold is located on the line that ranges from 50 mA for 1 second, at 40 mA for longer than 3 seconds Other Effects of Electric Current

Among other effects include:

  • Brain injuries
  • Epiglottis Block web
  • Laryngospasm
  • Coronary spasm
  • Global shock
  • Burns
  • Increased blood pressure, etc.

Factors Involved in Electrical Accidents

  • Value of the intensity of electric current
  • Value of stress
  • Time of passage of electric current
  • Impedance the human body (Z)
  • Career to continue the current through the body
  • Nature of current
  • Frequency value in the case of alternating currents
  • Reaction capacity of the organism

Effects of Current in the Human Body

  • 15 mA: initiation of cramps
  • Between 30 mA and 50 mA: Cramps growing
  • Between 40 and 70 mA.: Asphyxiation
  • From 70 onwards: cardiac fibrillation

Value Produced by a Current Depending on the Intensity and Time

Joule’s law: Q = U · t · 0.24 calories

This formula defines the heat released by the body when subjected to the REBT tension. According to fixed voltages The following security settings:

  • 24 volts for local drivers or locations
  • 50 volts for the remaining cases

Internal Impedance of the Human Body

This name is given to the impedance seen between two electrodes in contact with the human body, the abolition of the electrodos. Its skin under resistive value is mainly because it depends heavily on the path of the current and less on the surface of contact. When it is very small (order of mm 2), the value of the impedance increases. Total Impedance of the Human Body

It is calculated by adding vectorially the internal impedance and skin impedance to both the current entry and exit. (Fig. 4.8) The impedance consists of a resistive and a capacitive component. Initial Resistance of the Human Body, What Does It Depend?

Depends mainly on the current path and second contact surface.