Figure 22: Open back access doors
LASER MODULE
The Laser Module includes four components named Match ‘Em, Real Stories / Real Surgery, The Light Zone, and Zap It. The components are distinctly separate (not sharing center kiosks). Each is discussed in detail in the following sections.
Description
At this red-framed activity table, visitors learn about different wavelengths of lasers used in laser surgery. Visitors control a "start button", three lit buttons used to select a certain type of laser, and a joy stick used to aim the selected laser at "targets" on a virtual patient.
The "start" button initiates an instructional video (DVD). After the video is completed, visitors select a surgical laser type by pushing one of three lit buttons. A brief clue is given and the visitor tries to point the laser beam (seen through a mist chamber) at a target area on the virtual patient corresponding to the typical laser use (tattoo removal, damaged knee cartilage removal, and vocal cord repair). The visitor is informed if they have matched the laser to the target area correctly, or they are told to try again.
Primary Components
The primary operational components include:
Table 1 provides additional details about the primary and support components.
Consumables / Spare Parts
Consumables associated with this activity are air filters and haze machine fluid. Available spare parts are listed in Table 2.
Special Instructions
When electrical power is supplied to Match ‘Em, extreme caution must be exercised by technical staff during any internal maintenance/repairs on this exhibit to avoid exposure to potential hazardous light conditions. Review Attachment 4 before performing any maintenance that involves opening any of the three access panels leading into the mist chamber or lasers housing.
General Maintenance
Maintenance items are generally simple and deal with exhibit ventilation/air filtering, the mist/fog system, lighting, and general cleaning. Table 3 provides specific maintenance steps necessary and their frequency. Table 3 also should be used to record that maintenance steps were completed as prescribed.
Compared to other Zap exhibits, the haze machine and mist chamber for Match ‘Em require frequent maintenance for continued proper operation and visual appeal. To perform maintenance steps, open the lower back mist chamber access doors (Fig. 22) and the front cover (Fig. 23) of the vertical kiosk (prop the cover up with the provided length of black painted wood, or similar). Make certain that the door interlocks immediately shut off the lasers when any access door to the mist chamber or central kiosk is opened. On the haze machine remote control (located just inside the back access panel), immediately switch the button to "off" to temporarily stop fog generation. It is easiest to enter/exit the mist chamber to perform maintenance by climbing in through the front cover opening (sit down on the "shelf" and just pull your legs in, being careful not to knock the wood prop out of place). Be careful that the floor may be slippery when stepping into the chamber. When maintenance is done, close the front access door, push the haze machine remote button to "on", and then close the rear access doors.
Figure 22: Open back access doors
Figure 23: Open front kiosk cover
Troubleshooting
Joystick needs to be replaced: Open the red activity tabletop cover with a round barrel key and prop up the cover. Disconnect the wiring (quick connects near the underside of the joystick) and then unscrew the four mounting screws. Replace with a new joystick from Zap spares making sure that all pre-numbered wire leads are connected properly to its matching wire. Additional joystick knobs also are available in Zap spares if needed.
Haze machine not working: Troubleshooting steps for several items that have been noted as problems with the haze machine (that may recur) are described below.
Note that for normal operations, the main power switch on the bottom back of the haze machine should be in the "on" position, but the upper haze switch should be in the "off" position (because the remote overrides the main machine haze control).
If repairs are done and fluid lines become partly or completely drained, the lines will need to be primed again before haze production resumes. To accomplish this, disconnect the remote control (be careful to depress the lock button on the remote cable before pulling it out of the machine’s rear jack) and remove the haze machine to an open area. Switch both the main power button and haze switch on the back of the haze machine to "on". Let the machine run continuously in this manner until the lines are filled again. Once mist is generated well, turn the haze switch off and let the unit run until it stops producing haze. Reinstall the haze machine in the mist chamber, reconnect the remote (turning the remote switch to "on"), and restore power to the machine.
Figure 24: Haze machine details
Figure 25: Haze machine air pump
Blue (argon) laser not working: If the blue laser does not work (such as after a facility-wide main power spike / surge), the system may simply need reset. To begin this process, open the lower, front access on the center kiosk to expose the laser systems (all lasers should be automatically shut off by the access panel interlock switch). Locate the blue laser power unit at the left bottom of the open cabinet (Fig. 26). Carefully pull this unit out of the cabinet just enough to allow access to the controls on its front panel. Turn off the interlock key switch (Fig. 27) by turning the key counterclockwise. Also turn off the main switch on the step-up/step-down transformer located in the right bottom side of the cabinet.
Figure 26: Power unit on bottom left
Figure 27: Interlock switch location
Make certain before restoring power (wait at least a minute) that the blue laser power unit toggle switches are set to "idle" and "cur.". Also, turn the two rotating knobs completely down (counterclockwise). Turn the interlock key clockwise and confirm that the "discharge" toggle switch is set to "on". Don laser safety glasses and then turn the main power switch of the step-up/step-down transformer back on. Next, make certain that no one else is around the exhibit (the exhibit gallery should be closed), then temporarily defeat the access panel interlock switch to restore all power. The blue laser should come back on line a short time later.
Carefully return the laser power unit to its original position in the left side of the cabinet (making sure that the fan inlet on the back is not blocked).
If the output of the blue laser is insufficient, the intensity can be increased as follows (this must first be approved by contacting Carnegie Science Center’s technical coordinator). To increase the beam intensity, carefully access the front controls of the power unit as described above. Again, don laser safety glasses and make certain no one else is around before temporarily defeating the access door interlock switch. Set the toggle switch to "run". Keep the other toggle switch set on "cur.". Slightly turn the current knob up (clockwise) until the beam intensity increases to the minimum acceptable level. Leave the controls set this way and return the power unit to its original position (be careful to leave space behind the unit for the ventilation fan intake).
Other problems: Refer to Cryosurgery – Fast Freeze troubleshooting section regarding problems such as:
COMPONENT NAME – REAL STORIES / REAL SURGERY
Description
A red-framed activity table where visitors choose from various labeled buttons to view video (DVD) segments on actual laser surgery procedures. The visitors control this activity by using four extra large red buttons (one each per video segment), plus one stop button.
Primary Components
The primary operational components include:
Table 1 provides further details about the primary and support components.
Consumables / Spare Parts
Air filters are the only consumable items associated with this activity. Spare parts available are listed in Table 2.
Special Instructions
None
General Maintenance
Maintenance is easy and involves exhibit ventilation/air filtering, lighting, and general cleaning. Follow Table 3 for specific maintenance items and their frequency. Also use the form to record that maintenance was completed.
Troubleshooting
Refer to Cryosurgery – Fast Freeze troubleshooting section regarding problems such as:
COMPONENT NAME – THE LIGHT ZONE
Description
A two-sided exhibit (a high and a low table) where visitors can investigate/explore the properties of both white light (projected from normal incandescent bulbs in enclosures with slits to allow the light to exit), and lasers (projected from multiple apertures around the table sides). The visitors are given acrylic lenses of multiple shape to move and to intersect the light beams and observe differences in reflection, refraction and transmission. Rotating mirrors are permanently mounted on the high table to allow visitors to reflect a laser beam at a target. Also, prisms are permanently mounted on each table to disperse the white light to reveal the light spectrum.
Primary Components
The primary operational components include:
Table 1 provides additional details about the primary and support components.
Consumables / Spare Parts
Air filters are the only consumable items associated with this activity. Spare parts available are listed in Table 2.
Special Instructions
Watch the tables to assure that the acrylic shapes are not placed by visitors on their sides, potentially projecting the laser beams into the eyes of visitors. Lay the shapes flat on the tables if found in this orientation.
Daily visual morning checks should be completed to assure that all incandescent lights and lasers are lit.
Extreme caution must be exercised by technical staff during any maintenance/repairs on this exhibit when power is on, to avoid looking directly into any of the laser beams or having eyes exposed to any reflected beam that is not significantly dispersed.
General Maintenance
Maintenance items are simple and deal with exhibit ventilation/air filtering, lighting, and general cleaning. Table 3 should be followed for specific items and their frequency. It also should be used to record that the prescribed maintenance has been completed.
Troubleshooting
Incandescent bulb needs to be replaced: First remove the flat, labeled cover (held on by four hex head screws) on the outside edge of the tabletop over the white incandescent bulb area. This will expose an inner cover/metal plate. Remove two flat head screws to free the inside metal plate. Replace the bulb with a similar bulb from Zap spares and reassemble the bulb covers.
Laser beam appears weak: Dust that accumulates on the tabletops can sometimes plug the aperture holes in the metal plate that the lasers are mounted to. First attempt to extract the dust using a strong vacuum. If this does not improve the beam intensity and it is very weak, replace the laser from Zap spares by removing the associated metal cover plate (held by hex head or phillips head screws). Once unscrewed, the top plates over the red lasers must be pried off carefully with a flat-head screwdriver to loosen them from steel dowel pins (Fig. 28). The entire green laser mounting assembly is loosened and then the back plates must also be removed to access the lasers. The green lasers are mounted in heat sinks with thermal conductor paste / heat sink grease (Fig. 29).
Prior to removing any of these metal plates, disconnect power to the activity table to prevent the laser beams from accidentally being projected into unprotected eyes.
When replacing a laser, be careful to mount the new laser so that the "warning" / output power label on the new laser body is visible (like the removed laser) through the window of the mount cover plate.
Laser not working: First check that the laser power pack is supplied with main power and plugged in securely. Next check that the power pack is producing the output specified on the back of the unit. As appropriate, replace the power pack, or laser itself, from Zap spares. Remember to disconnect power before initiating replacement for safety.
Figure 28: Red laser assembly
Figure 29: Green laser assembly
Description
A large mock up of an eyeball, where visitors perform simulated surgery to seal leaking blood vessels on the retina. The visitor aims a laser at multiple lit LEDs (signifying leaking vessels). Each LED is extinguished and a "zap" is heard when the blood vessel is hit successfully with the laser. The exhibit resets itself for the next visitor when all targets are hit, or a reset button can be depressed at any time.
Primary Components
The primary operational components include:
Table 1 provides details about all primary and associated components.
Consumables / Spare Parts
No consumables are associated with this exhibit. Table 2 lists available spare parts.
Special Instructions
Extreme caution must be exercised by technical staff during any maintenance/repairs on this exhibit when power is on, to avoid looking directly into the laser beam or having eyes exposed to any reflected beam that is not significantly dispersed. This applies to situations such as when the eyeball rear access cover may be opened to access the target circuits, or when the front tabletop is opened/tilted back and the laser beam points away from the eyeball.
General Maintenance
Maintenance is simple and deals with exhibit lighting and general cleaning. Table 3 should be followed for specific maintenance items and their frequency. Use Table 3 to record that maintenance was completed as prescribed.
Troubleshooting
Laser weak or not working: Refer to Lasers – Light Zone troubleshooting section for general directions. To replace the laser, turn off power to the laser, open the front table panel (remove two hex head screws and tilt the table top backward), and remove three hex head screws on the front of the "gun" to loosen the front mount pieces and free the laser. Obtain a replacement laser from Zap spares (the red laser is the same as those used in Lasers – The Light Zone).
Target LED not lit or photoelectric cell not responding to laser beam: Each target is an individual custom circuit board with an LED and photoelectric cell. In order to access these circuits for replacement/servicing, disconnect main power to the exhibit to prevent eye exposure to the direct laser beam. Remove the four hex head screws on the rear, top panel of the eyeball (Fig. 30) and carefully pull/lift this panel off (it is heavy) to access the circuits (note the orientation of the cover when removing it, so that it is properly replaced).
If one target is not responding to the laser beam, first attempt adjustment of the blue potentiometer on the rear circuit board of the problem target, rather than immediately replacing the circuit board. This can increase the target sensitivity. If this does not resolve the problem, replace the individual circuit board as described below. If multiple targets are not responding to the laser beam, it is more likely that the laser has weakened and it is best to replace the laser (as described in the section above), rather than adjust multiple circuit board potentiometers.
To replace a circuit board, unplug the problem board, unscrew the mounting screws (Fig. 31), and replace the circuit board from Zap spares. To avoid damage to the eyeball back cover, be careful to start all screws by hand and get it oriented properly (note three alignment lugs on the back opening) before tightening the screws.
Figure 30: Removed top rear panel
Figure 31: Circuit boards
Other problems: Refer to Cryosurgery – Fast Freeze troubleshooting section (except disregard reference to DVD player and infrared transmitter) for problems such as: