Many technological factors distinguish standard commercial power supply units from medical grade power supplies. Commercially manufactured units are produced to certain standards, but it has been deemed that these standards are not high enough for medical grade equipment, where the power supply plays a vital role in the diagnosis and treatment of patients. Reliability and safety are of paramount concern, so stricter quality control standards are placed on manufacturers producing equipment for the medical profession.



Medical grade power supplies have to conform to set safety standards and within those standards there are specific requirements. Most of these requirements relate to the design and test criteria that seek to eliminate the potential of shock hazard to patients and operators. The primary source of this can be current leakage. Current leakage is an unwanted transfer of energy from one circuit to another. For example, magnetic lines of flux will not be entirely confined within the core of a power transformer; another circuit may couple to the transformer and receive some leaked energy at the frequency of the electric mains. This potentially damaging to the power supply unit, the internal electronics and ultimately to the patient. Because of the increased risk to vulnerable patients, current leakage limits on medical grade power supplies are one tenth of those for other commercial power supply units.

However, the regulations on current leakage are not the only aspect of medical grade power supplies that is of a higher standard. Medical grade supplies must also satisfy recently introduced standards for power factor correction and standards already in force for electromagnetic interference (EMI).

Power factor correction is the means of increasing the power factor within an electrical system and therefore its efficiency. This is achieved by using power factor correction capacitors, which are specially designed capacitors used specifically for power factor correction. The primary function of a capacitor is to store electricity using an electric field. Due to its physical nature, the capacitor has a tendency to maintain a constant voltage. When the voltage drops on an electrical system the capacitor will release some of the electricity stored within itself to correct this drop. Medical grade power supplies incorporate this system which allows medical facilities to operate more equipment from the same line because the peak current is less for the same amount of power. Equipment that is more energy efficient is becoming an increasing priority to energy hungry environments such as medical establishments. It also reduces the risk of power surges damaging equipment at critical points and possibly endangering the life of the patient.

Electromagnetic interference can be extremely destructive. EMI is an electromagnetic disturbance that degrades or limits the effective performance of electronic or electrical equipment, so it's implications within a medical environment are obvious. Medical grade power supplies have incorporated various systems to minimize the risk of EMI interfering with the operation of other equipment through proper cable shielding, dealing with the problem of electrostatic discharge and other common causes of EMI. Again, these standards are far higher for medical grade power supplies than for other commercial units, as the consequences within a medical environment are potentially far more life threatening.

So the primary reason for choosing medical grade power supplies is a duty of care to the patient and operators. The stringent safety demands placed on manufacturers of these power supplies far outweigh those of other manufacturers, so you can be certain that the equipment you buy from a medical grade power supplies specialist is of the highest quality.