Re: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester
Thanks Owen, This particular tester as I know does not reference the high potential created to the ground. So as long the operator does not become part of the circuit, (that's why the electrodes are designed as they are) there is nothing to worry. Of course the EM waves generated when you make and break the circuit are too feeble to affect any type of receiver of this radiation. More on radiation is at: http://en.wikipedia.org/wiki/Electromagnetic_radiation I think it is safe inherently for all users. Regards, Sanjeev Hiremath www.hiremaths.com Sent from my iPad On 18/07/2012, at 10:10 PM, "Owen Byrnes" wrote: > Hello bmelist, > > The HiPOT tester that I am referring to is a porosity tester manufactured in > Australia that is designed to test the insulation coating of electrosurgical > instruments for holes in the insulation. The tester’s model name is HiPOT. > > This porosity tester has been designed so that it can be safely used by > hospital staff for conductivity and porosity testing of electrosurgical > instruments and leads. > > This porosity tester should not be confused with equipment used for high > potential (Hipot) testing to verify the electrical insulation of electrical > appliances, cables or other wired assemblies, printed circuit boards, > electric motors, and transformers. > > Sorry for the confusion I may have caused for list subscribers who were not > aware that I was referring to a specific model of porosity tester. > > Thanks, > Owen. > > Owen Byrnes >
RE: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester
Hello bmelist, The HiPOT tester that I am referring to is a porosity tester manufactured in Australia that is designed to test the insulation coating of electrosurgical instruments for holes in the insulation. The tester's model name is HiPOT. This porosity tester has been designed so that it can be safely used by hospital staff for conductivity and porosity testing of electrosurgical instruments and leads. This porosity tester should not be confused with equipment used for high potential (Hipot) testing to verify the electrical insulation of electrical appliances, cables or other wired assemblies, printed circuit boards, electric motors, and transformers. Sorry for the confusion I may have caused for list subscribers who were not aware that I was referring to a specific model of porosity tester. Thanks, Owen. Owen Byrnes
FW: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester
FYI From: markel...@gmail.com [mailto:markel...@gmail.com] On Behalf Of Mark Littlejohn Sent: Tuesday, 17 July 2012 10:09 AM To: Owen Byrnes Subject: Re: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester Pregnant Women and HiPOT testing I need to declare that I have a vested interest in this as a manufacturer, however I have some references and data that may be useful as guidance for Biomeds. I usually don't reference Wiki but it is fairly accessable http://en.wikipedia.org/wiki/Spark_gap which says in part- "Health hazards Exposure to an arc-producing device can pose health hazards. In a closed space such as a classroom or home, the continuous arc formation of an open-air Jacob's Ladder will ionize oxygen and nitrogen, which then re-form into reactive molecules such as <http://en.wikipedia.org/wiki/Ozone> ozone and <http://en.wikipedia.org/wiki/Nitric_oxide> nitric oxide. These <http://en.wikipedia.org/wiki/Free_radicals> free radicals can be damaging to the <http://en.wikipedia.org/wiki/Mucous_membranes> mucous membranes of people near the spark gap. Plants are also susceptible to ozone poisoning. These hazards are not present when the arc is formed outdoors since the heated ionized gases will rise up into the air and dissipate into the atmosphere. Spark gaps which only intermittently produce short spark bursts are also minimally hazardous because the volume of ions generated is very small. Arcs can also produce a broad spectrum of wavelengths spanning the visible light and the invisible ultraviolet and infrared spectrum. Very intense arcs generated by means such as <http://en.wikipedia.org/wiki/Arc_welding> arc welding can produce significant amounts of ultraviolet which is damaging to the retina of the observer. These arcs should only be observed through special dark filters which reduce the arc intensity and shield the observer's eyes from the ultraviolet rays." I have not been able to find any references to XRay generation, except perhaps in reference to TV CRT's where you accellerate electrons at approx 25kV over approx 400mm, which is noted that it can produce low level soft Xrays. However health risks would be only elevated over the background radiation after long term continuous exposure. The voltage outputs of the HiPOT 150 tester is 4.34kV @ 120MegOhms and 1kV @ 33MegOhm yielding currents of approx 30uA which is well under the Applied Part Leakage Normal Condition (BF 100uA) and also Mains on Applied Part leakage (BF 500uA). These currents are sufficiently low for monitoring equipment used in labour wards, and that the current path of the HiPOT (if used with the wrist strap) should not involve the Uterus. There is higher peak currents available from the discharge of the stray capacitance. This stray capacitance and static discharge is always present (especially in cars, new carpets etc) and naturally occuring static charges can be up to 20kV (note the ESD protection for MOS devices). The wrist strap discharges static build up in the stray capacitance through a 1MegOhm resistor (as per the standard for ESD). Mark Littlejohn ElectroLAB P/L 129 Ala Moana Rd East Kurrajong NSW 2758 Ph61 2 4573 0591 Fax 61 2 4573 0592
FW: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester
FYI From: Smith, Michael C (Health) [mailto:michaelc.sm...@health.sa.gov.au] Sent: Tuesday, 17 July 2012 9:38 AM To: Owen Byrnes Cc: Beesley, Jack (Health) Subject: RE: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester Hi there Owen, Interesting question. HiPots are typically kV testers, running at DC, producing about 5 mA at most (some go to 10 mA). (http://www.atecorp.com/categories/hipots/hipot_leakage_above_40kv.asp) For electric shock, current delivered is critical, not voltage. 5 mA DC is just on the threshold of perception. This means that a pregnant woman exposed to the maximum current of a HiPot tester might be only just able to feel it, but would not normally be at risk of pain or injury. What about the current delivered to a fetus? There seems to be nothing in the literature about HiPot tester injuries to mothers or foetuses. Most articles are concerned with regular electric shock to mothers, which while hazardous to mothers, seems not to pose a major risk to a foetus. My conclusion is that the risk of fetal injury from a HiPot tester is similar to or less than other common workplace risks encountered while working in a Biomed workshop or electronics lab. Some other conclusions: "The fetus is much less resistant to electricshock than the mother. Any woman who suffers from an electric shock in pregnancy, however minor, requires prompt fetal monitoring and careful obstetric supervision." http://www.sciencedirect.com/science/article/pii/073646799390516A "In most cases accidental electric shock occurring during day-to-day life during pregnancy does not pose a major fetal risk." http://www.sciencedirect.com/science/article/pii/S0002937897705696 "Temporary and permanent pacing have been used safely during pregnancy, as has direct current cardioversion" http://www.sciencedirect.com/science/article/pii/000287039590090X regards, Michael Smith. (BE (Elec), MBiomedE) Biomedical Engineering Flinders Medical Centre From: Owen Byrnes [mailto:o...@ozdolphin.net] Sent: Monday, 16 July 2012 9:50 PM To: bmelist@bme.asn.au Subject: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester Question 1: What are the risks for a pregnant woman doing testing with a HiPOT insulation tester? Question 2: Should a pregnant woman be performing this type of testing?
FW: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester
Hello Michael Smith, Mark Littlejohn, and Robert Barnett, I was asked similar questions several years ago when I was training CSSD staff on using a HiPOT tester for insulation testing of electrosurgical instruments. As you have identified, the concern was for the unborn foetus, not the pregnant woman. At the time, due to the extremely low current output of the HiPOT tester, I did not believe that there was a risk. However a lingering doubt has continued to plague me. Thanks for your responses. I have forwarded them to the bmelist because I think the additional information is useful. Thanks also to the others who responded. Please excuse me for being selective about the responses I have forwarded. I greatly appreciate your responses as well. Thanks. Owen. Owen Byrnes Mob: 0411353889 From: Owen Byrnes [mailto:o...@ozdolphin.net] Sent: Monday, 16 July 2012 9:50 PM To: bmelist@bme.asn.au Subject: [bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester Question 1: What are the risks for a pregnant woman doing testing with a HiPOT insulation tester? Question 2: Should a pregnant woman be performing this type of testing?
[bmelist] Re: Laproscopic instrument testing with an HiPOT insulation tester
Question 1: What are the risks for a pregnant woman doing testing with a HiPOT insulation tester? Question 2: Should a pregnant woman be performing this type of testing?
