Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!ll-xn!cit-vax!amdahl!sjl From: sjl@amdahl.UUCP (Steve Langdon) Newsgroups: net.micro.mac Subject: Re: Medical Uses of a MAC Message-ID: <3591@amdahl.UUCP> Date: Fri, 29-Aug-86 02:02:51 EDT Article-I.D.: amdahl.3591 Posted: Fri Aug 29 02:02:51 1986 Date-Received: Fri, 29-Aug-86 05:48:10 EDT References: <3034@caip.RUTGERS.EDU> <266@dmsd.UUCP> <3544@amdahl.UUCP> <267@dmsd.UUCP> Reply-To: sjl@amdahl.UUCP (Steve Langdon) Organization: Amdahl Corp, Advanced Systems Planning Lines: 83 Keywords: Parity Mac Medical Risks Summary: Longer explanation of system design principles In article <267@dmsd.UUCP> bass@dmsd.UUCP (John Bass) quotes my reply to his earlier posting on this subject, and says: > > I have used macs for nearly two years, and have noticed both memory and > disk data corruption without comment from either the OS or hardware. > Unreported disk read errors resulting in random software failures are common > on Macs -- Most people just try another disk or drive and live with it. > I shudder to think my life might require trusting a mac somewhere. > > Before ANY software validition can be correct its LOADED and RUNNING image > must be correct -- I.E. reliance on distorted software is futile. I hope > that Stephen is not suggesting that it's hopeless so why bother. I contend that > certain MINIMUM AND RELIABLE hardware checks are necessary to support higher > level decisions on integrity. In critical applications this includes power > certification, hardware certification, AND SOFTWARE certification. The Mac > is extremely at a disadvantage here since it lacks both minimum hardware error > detection and hardware memory management to protect the OS from corruption by > applications (which may distort operation of applications run at a later time). > > Will Stephen please clearify what he disagrees with??? Is he really suggesting > that the hardware checks are not necessary and that software only checks are > enough?? Or does he agree that minimum hardware checks are necessary, and that > I am in error only by not taking a stronger stand, I.E. requiring that the > system environment, system hardware, and system software must all be validated?? > ... I am saying that you must carefully analyze the requirements of the application and ensure that the complete system meets the appropriate criteria. This includes the hardware, software, and human aspects of the system design. Checks and balances involving each of these elements are often necessary. It is also important to avoid over-specifying a system just because a code word like "medical" is used; in the DOD procurement area this is known as "gold plating". The original request was: > I am in medical school, and am designing and installing medical office > systems. I would like a good package for the MAC. BUT I need to FIND ON > first!!! I do not believe that the Mac is any less suitable to keep track of a doctor's calendar than any of the other micros that might be used. The other causes of error in this application are so much more significant than those introduced by a micro (even without parity) that it would be stupid to demand triple-redundancy or other such measures used in highly sensitive applications. Other follow-up messages showed examples of appropriate use of the Mac in medicine. For example: > ... I use the Mac for everything from writing manuscripts > for publications to creating exhibits for meetings to organizing and > managing patient data... > I would have to agree with Franklin Tessler that the Mac is a > wonderful tool for the physician who is in the business of information > transfer. Many fields of medicine are very visually dependent, such as > radiology, pathology, surgery, etc. In order to transfer information, > diagrams are often a necessary part of the process. There is no better > desktop computer on the market for this type of work. Granted, the > ... > By the way, there is software available right this very moment for > sportmedicine. I happen to have a nice template for Filevision that combines > anatomic diagrams interactively with the database of information on various > jogging, skiing, etc. minor injuries. It is a very effective way of keeping > track of this information, for reference as well as patient education. I'd be > glad to send you a demo if your interested. I don't believe that there is > anything on the IBM that even comes close to the filevision program. Both these quotes describe applications that the Mac fits well. I doubt that many would argue with the clerical applications, but those who worry about graphic applications such as radiology should consider the error properties of the sensors. Even if one were to incorrectly assume perfect input, how many frame buffers have parity, let alone ECC? On the other hand, if the computer running a life-support system relied on normal commercial quality error detection hardware I would be aghast. Careful use of reliable hardware, paranoid software, and alert users is essential. I hope that this rather longer explanation of my views provides the clarification John (and possibly others) wanted. -- Steve Langdon ...!{decwrl,sun,hplabs,ihnp4,cbosgd}!amdahl!sjl +1 408 746 6970 [I speak for myself not others.]