Personally I like the idea of applying common sense via risk management, but I am not sure that invoking the ubiquity of non-medical electrical devices, though possibly persuasive in front of one particular reviewer, is the best way to go.
Here are two possible avenues to criticize this approach:
1) Certification for use in a home healthcare environment (60601-1-11) does not relax requirements but rather imposes additional ones, and in no way precludes operation in a hospital environment.
2) Even given the likelihood of operation in an environment where other electrical devices are present which are not 60601-1 compliant, doesn't the medical standard prescribe that devices conforming to it themselves present a lower level of risk, regardless of the presence of other risks?
The conflict between the standard and common sense arises from the notion embedded in 60601-1 that anyone in the role of a "patient" must be more rigorously protected than he would be in another role, regardless of his condition.
This heightened concern for diminishing patient risk makes sense under the worst-case assumption (about the patient's state) that he is weakened, immobilized or unconscious, and connected up to potentially hazardous equipment.
However in some cases the very nature of the equipment practically guarantees that anyone performing a given operation, whether deemed patient or operator, is in quite a normal state compared to the worst case assumption. So indeed a heightened concern for electric shock risk makes no sense in the scenario of a (certainly conscious and responsible) patient-operator plugging a battery charger into a piece of diagnostic equipment.
The approach I would take to risk management, if I had to invoke it to justify use of a charger with higher touch current, would be to would argue that all patients are not equal, and that a higher touch current simply does not represent a heightened risk to any "patient" who is operating diagnostic equipment on his own behalf.
In the future perhaps the standard should either clarify conditions under which the patient and operator may be the same person, and specify that operator protection may apply in some such cases; or else make the distinction between various levels of "patient", with regard to his ability to react to and survive hazardous events.
Here are two possible avenues to criticize this approach:
1) Certification for use in a home healthcare environment (60601-1-11) does not relax requirements but rather imposes additional ones, and in no way precludes operation in a hospital environment.
2) Even given the likelihood of operation in an environment where other electrical devices are present which are not 60601-1 compliant, doesn't the medical standard prescribe that devices conforming to it themselves present a lower level of risk, regardless of the presence of other risks?
The conflict between the standard and common sense arises from the notion embedded in 60601-1 that anyone in the role of a "patient" must be more rigorously protected than he would be in another role, regardless of his condition.
This heightened concern for diminishing patient risk makes sense under the worst-case assumption (about the patient's state) that he is weakened, immobilized or unconscious, and connected up to potentially hazardous equipment.
However in some cases the very nature of the equipment practically guarantees that anyone performing a given operation, whether deemed patient or operator, is in quite a normal state compared to the worst case assumption. So indeed a heightened concern for electric shock risk makes no sense in the scenario of a (certainly conscious and responsible) patient-operator plugging a battery charger into a piece of diagnostic equipment.
The approach I would take to risk management, if I had to invoke it to justify use of a charger with higher touch current, would be to would argue that all patients are not equal, and that a higher touch current simply does not represent a heightened risk to any "patient" who is operating diagnostic equipment on his own behalf.
In the future perhaps the standard should either clarify conditions under which the patient and operator may be the same person, and specify that operator protection may apply in some such cases; or else make the distinction between various levels of "patient", with regard to his ability to react to and survive hazardous events.
Last edited: