Microcontroller project

      This is my first microcontroller project. An AT89C52 microcontroller with the MCS BASIC-52 located in internal  8K of ROM. 8K of STATIC RAM and 8K of NVRAM are used for program execution and program storage
       A 82C55 peripheral interface feeds the LCD display. A AD558 an 8-bit digital-to-analog converter was added and has yet to be used.The Microcontroller idea book by jan Axelson provides pretty much all of the circuitry that I used.
     The MCS BASIC-52 Language was made public domain by Microsoft a while ago. BASIC-52 was loaded into the 89C52 ROM using an Iquana labs PG302 interface and a ADT87 zif adapter.
     All of this software and a lot more info is on the web. I Have the BASIC-52 instruction manual as a Word file and a small number of programmed/ unprogrammed 89C52 chips available for the cost of shipping. My email address is cbet@aol.com. She ain't pretty, but she works.

Anesthetic gases and workplace exposures

This .gov article just might convince you to do trace gas testing at your Hospital.
http://www.osha.gov/dts/osta/anestheticgases/index.html#C1

Hyfrecator safety issues

The Conmed 2000 Hyfrecator

                This little rascal  deserves some study. I was recently reminded that potential shock or burn hazards can exist. It is most commonly  used as a monopolar, ground referenced ESU with about 30 watts output.  The ground reference is made through the green wire in the power cord. The patient’s body is capacitive coupled through the air to ground, completing the circuit.

            The operators manual describes the necessary precautions to be taken.

I found the operators manual at :

http://www.promed.ie/shop/assets/catalog/parts/Hyfrecator%20200%20Manual1.pdf

Solar powered LA battery charger

 Solar powered battery charger

                  This solar charger circuit is used to charge a twelve-volt, lead acid battery. The battery in turn, can supply any device within its power capacity.

This circuit will charge a variety of SLA batteries up to about 3 Ah. The circuit will reduce the charge current as the battery reaches its Vmax, and the comparator shuts off the MOSFET. You will need the Vmax spec for the battery you are using.

Adjust the potentiometer until the point where battery voltage equals Vmax and current no longer flows. Placing the circuit and solar panel in a reflective, hinged box will boost output and protect the panel when not in use.

The original  design is from the web, by Oscar den Uijl,  odu@xs4all.nl at http://www.electronics-lab.com/projects/power/031/. I eliminated some parts and added a charging current meter.

    

Medtronic education site

So I am looking for education opportunities to help with my CBET certification and visit https://wwwp.medtronic.com/mdtConnectPortal/registration/index.jsp. Just create a log in and on the CONNECT PAGE there are lots of cool education videos and powerpoint presentations. I looked under "Therapies and Procedures and selected "Temporary pacing". We use Medtronic 5388 dual chamber external pacemakers. I think the tutorials are great.

Static hazards in Biomed world

It has been my personal experience to learn some things the hard way, several times.
      All our work stations in our Biomed shop have anti static pads and wrist straps. Just a reminder that these pads and straps wear out pretty quickly. We replace our anti static gear every two years.
We all wear our wrist straps during any equipment disassembly . Up in patient areas, "Yes, our shop is in the basement"remember that static can damage equipment modules that are carried from place to place. Ask nursing staff to avoid touching the metal connections  Wikapedia says  http://en.wikipedia.org/wiki/Antistatic_wrist_strap

Isolated Power Systems

This site rocks for describing Isolated power from all sides. I think that this subject is often misunderstood and may be under served as a topic for preventive maintenance.
http://stevenengineering.com/tech_support/PDFs/45HIPS.pdf