rothlis
Involved In Discussions
Hi all,
We are looking at using compliance with clause 11.2.2.1 to establish whether it is safe to use our device in the operating room during clinical research, where it will be used at the patient's ears. Despite Peter Selvey's observation that the standard is actually concerned with areas inside the ME EQUIPMENT, we are conservatively assuming that leaks from a mask or nasal cannula could feasibly result in an oxygen concentration > 25% in the immediate area where our device is used.
Our design meets the criteria of "a source of ignition" according to Figure 36 due to the presence of 40 V on a capacitive circuit. The 300 trial ignition test does not easily fit into our current schedule, so we were hoping that we could build upon the standard's advice that "Items 4) and 5) address the worst case where the atmosphere is 100 % oxygen, the contact material (for item 5) is solder and the fuel is cotton. Available fuels and oxygen concentrations should be taken into consideration when applying these specific requirements. Where deviations from these worst case limits are made (based on lower oxygen concentrations or less flammable fuels) they shall be justified and documented in the RISK MANAGEMENT FILE."
Does anybody have any experience justifying deviation from the worst case limits? Our thinking was that the best way to do this would be to locate the origin of the Figure 36 graph and work from the data which informed it to generate a new graph based on our less-than-worst-case conditions, but we have been unable to track that down. Or are there any other suggestions on how to tackle this?
Thanks in advance.
We are looking at using compliance with clause 11.2.2.1 to establish whether it is safe to use our device in the operating room during clinical research, where it will be used at the patient's ears. Despite Peter Selvey's observation that the standard is actually concerned with areas inside the ME EQUIPMENT, we are conservatively assuming that leaks from a mask or nasal cannula could feasibly result in an oxygen concentration > 25% in the immediate area where our device is used.
Our design meets the criteria of "a source of ignition" according to Figure 36 due to the presence of 40 V on a capacitive circuit. The 300 trial ignition test does not easily fit into our current schedule, so we were hoping that we could build upon the standard's advice that "Items 4) and 5) address the worst case where the atmosphere is 100 % oxygen, the contact material (for item 5) is solder and the fuel is cotton. Available fuels and oxygen concentrations should be taken into consideration when applying these specific requirements. Where deviations from these worst case limits are made (based on lower oxygen concentrations or less flammable fuels) they shall be justified and documented in the RISK MANAGEMENT FILE."
Does anybody have any experience justifying deviation from the worst case limits? Our thinking was that the best way to do this would be to locate the origin of the Figure 36 graph and work from the data which informed it to generate a new graph based on our less-than-worst-case conditions, but we have been unable to track that down. Or are there any other suggestions on how to tackle this?
Thanks in advance.