General comments
There were 30 instructors and qualified guests at the review.

Overall there has been substantial progress since the mockup review. This is a good thing and provides reason for satisfaction. However, for several projects key aspects of the designs are working but the prototypes are closer to mockups than designed products. In a few cases the prototype designs are more finalized but there are key functions yet to be realized. So all teams still face some significant challenges on route to the alpha prototype and final presentation.

It is now critical to design and execute the devices as coherent, integrated, elegantly-resolved products, thinking carefully about overall form, human factors, efficient use of materials, ease of fabrication, cost and user safety. If you have questions about how your team might go about this, please feel free to ask the course instructor for a design consultation. It is critical that key design decisions are made before the Thanksgiving break next week, and redesign is well underway.

For teams with key functional aspects or system integration issues yet to resolve, it is very important to tackle these problems soon in order to avoid surprises a day or two before the final presentation. There may be undiscovered problems. The core, integrated functionality should be solidly resolved no later than the Wednesday after Thanksgiving so there is time for testing, some redesign, and planning and preparation for the final presentation.

All teams should aim to have the prototypes completely ready and available for presentation practice by the Saturday before the final presentation at the latest.

Team-specific comments/suggestions intended to help each team with preparation for the final presentation are provided below. Please consider these comments before setting priorities before the holiday, and feel free to ask if there are questions. You will also receive comments from individual instructors over the remainder of this week. The average scores for each prototype are at the bottom of the page.

Your team will need to take a split approach over the final weeks, working on the prototype and at the same time designing/preparing materials for the final presentation, where a large number of product development experts (~150) from industry will review the projects.

To view a team's prototype and provide feedback, click on the links provided below.

Team-specific comments and suggestions
red, green, blue, yellow, orange, purple, silver, pink

Red: AirWare
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The concept direction has improved significantly over the past few days, and the basic functionality is close. Now, it is critical to take the idea and make it into a product.

Some thoughts follow.

• overall, the device needs to look cool. Elegant integration of the tubing, the filling port, and the regulator are all issues. The device needs to be stylish. The less bulky the better.
• a shorter length of larger diameter, supple, less expensive, ~300 PSI tubing seems appropriate. The length of tube might be as little as a couple body lengths. Fittings can be used for corners if needed. Scuba tubing is likely not the direction to pursue.
• there should be a relief valve so that the tube cannot be pressurized over the design's intended pressure.
• having the mouthpiece on the arm might help prevent people from using it in a way that might lead to air embolisms, but it still seems difficult to reach.
• feedback about whether the device is charged might be useful.
• working with a sewing professional might help with aspects of the prototype.
• while not part of the technical review, many reviewers were concerned about the market size. You will need to prepare a thoughtful, well researched preliminary business model for the final presentation.

Green: Roll and rise walker
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The team has done a lot of work but there are major system integration, usability, and safety issues to be addressed. Visually, the walker looks mechanistic and intimidating. Would it be embarrassing for a user?

Also, critically, it seems quite unlikely that people would use the device all the time only for the off chance occasion that they might fall. It seems important for the walker to have a good, regular useful purpose. Helping to kneel down to reach low items? Transferring items from surfaces at different heights?

Some suggestions follow.

• it needs to be designed as a whole, from the outside in.
• the design is quite complex to use, and it seems unlikely people would remember how to use it. It is critical to walk through the human-use process and simplify. It was also difficult to get onto the seat.
• there were many, many pinch points, catch points, and potential trip points. Older users might often be wearing loose clothing or sweaters that could even become wound in the lead screws. Sharp corners will break fragile skin.
• the design felt very flexible and potentially scary or unsafe, with the potential for falling off the seat. Torsional stiffness of the walker is important. Stability is also critical.
• the controls need to be simple and intuitive. The come-along control was confusing and also seems visually inappropriate.
• dangling wires and cables are potential hazards that should be avoided.
• it was not clear what the plan was for recharging and understanding the state of charge.

Blue: Variable buoyancy backboard
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The basic function of the design is working, but now it needs to be designed as an overall product. Details need to be resolved cleanly, and careful thought needs to go into the selection of appropriate materials for the bladder and the backboard materials. Also, specialized fittings might allow the plumbing of the device to be much cleaner.

Some considerations follow.

• the devices are surprisingly unstable. Given that you have bladders, can they not be designed so that the device floats stably when inflated? This seems like it could be a significant improvement and a strong selling point.
• it seems like different height occupants may present an issue. Can there be indications so different users can be positioned so that the device floats evenly?
• the inflation buttons seemed hard to find, and in a place where they might accidentally be pressed when carrying the backboard. There should be clear feedback on when to stop inflating the device.
• it would be good to easily see the state of charge/air reserve from the top of the board
• the head restraint mechanism seemed fairly fiddley to adjust.
• the rub strips might be placed on top of the bladders.

Yellow: BLP assembler
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There were many subsystems that have been worked on. This is useful for identifying issues and defining the process, but most of the parts and the overall system seemed ad-hoc in design and implemented like mockups or sketch models. It is critical to design the overall process as an integrated whole, carefully designing/detailing the components and selecting appropriate materials. It seems like a robust, durable, easy to maintain and service device is appropriate for the application. Loose parts often end up being scavenged for use in other applications.

Some details to consider are below.

• the heat sealing and cutting mechanism has challenges, but can be improved to be easier to make, improve throughput, and work reliably. Please ask for more details.
• overall, the process seemed complex and hard to learn and keep track of. Economy of steps and user motion is important in process design. There was a lot to do for two people. Please ask for more details.
• there are concerns about occupational hazards. Can you characterize the dust particulate size and use this information to do a preliminary assessment of health risks.
• it seemed like the blower was working at too low a velocity/pressure to work reliably.
• the metering of the raw material into the system seems like a concern. Please ask for more details.

Orange: Helmet 911
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The preliminary prototype seemed to provide the basic functionality, which is good. However, there was some confusion about what was or was not working. Some reviewers left thinking that the GPS module was not functioning in the prototype, while others thought that it was. It is important to clearly communicate what functionality is implemented, and what functionality is desired.

Additional suggestions and questions are listed below.

• there are many permutations of what the product might be, and different team members seem to have different visions. You need to decide what the use model is, what the product will be, and then implement an appropriate design. Have a clear vision for its use and the business model, and then design the system.
• many were concerned that it would not likely be on the bike for the one time it is needed if it is special purpose. It seems like integration with something else that would always be on the bike for normal use might be a good strategy.
• protruding elements, such as the switches in the prototype or LEDs will ram into and potentially damage the device on impact.
• feedback about whether it is working is a concern.
• false positives were a concern. Some reviewer wonder about supervisory services or being set to call somebody else's phone rather than 911.
• the ergonomics of the buttons on top of the helmet were challenging.
  

Purple: Easy up walker
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It was good to explore options in more detail, but both are at mockup level execution and it is important that you make a decision about what direction to pursue. Both items had usability issues that would need to be resolved.

Overall, the 32 reviewers collectively had a positive interest in the "push-down" or "kneeling" walker concept. Thus, the discussion tended to center on that design.

Some suggestions/considerations are listed below.

• the design needs to address how to tailor/setup the design for a specific user. Short users had a much easier time than taller users. At the final presentation a wide range of users will want to test the device.
• any design, static or otherwise, needs to be stiff, robust and reassuring.
• any design needs to be smooth and without catch points or protruding fasteners.
• the form of the walkers should be refined, thinking carefully about proportions and form vocabulary. Can the walker be special, or should it look like other institutional walkers?
• all failure modes need to leave the walker in a safe state.
• need to consider the issue of a person that gets halfway up and starts to fall back. Should the device hold position so that they are supported, or should it lower them back to the seat?
• the device needs to be smooth since corners will break fragile skin, and not have catch points.
• the cable release mechanism seems problematic, and the release control seems to be located where it might accidentally be triggered. Would a direct actuation on the pivot//lock be more appropriate?
• clear feedback (auditory or otherwise) seems important to let the user know when it is in normal walker mode.
• the static design seemed a bit low for many users, and overall seemed to be quite large and bulky.
  

Silver: ice saber
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The prototype scored well in the review because it seemed the most product-like of all the projects. The overall form can and should be further refined, but this is a start.

However, it is important to also realize that the device's core function is marginal. It ran but did not really work. It seemed like the modified reciprocating sander or the flush cut saw experiments had better performance. Several reviewers felt that the traditional scraper had better performance.

A few other comments are:

• there seems to be 3 key aspects to consider: the frequency, the amplitude, and the blade design (stiffness, cutting edge design). It seems like additional, careful exploration of the parameters may be in order.
• the ice cutter feature on the back of the blade did not work. Also, the rotating scraper head did not seem like an advantage to reviewers. It prevented using a corner to get down to the glass.
• the noise level is not acceptable. It would violate residential noise bylaws (typically 9 PM - 7 AM) that are common in many residential areas. The noise seems inherent to the design. The actuation method may need to be reconsidered. Also, it seems unlikely that the blade is following the cam at the operating frequency of the device. A direct linkage may be needed.
• there was a lot of concern about the cost of the product, and the significant cost of the selected batteries.
• overall, the device seemed large, and the form can be further refined. There was discussion that a weapon imagery may not be appropriate.
• the switch needs to be large/easy to find, waterproof, and in a location that is not easy to accidentally switch while in use. The idea of a device that did not require manual activation was brought up by many reviewers.
• testing is still a concern. Having more realistic ice is important. Also, knowing and controlling the temperature of the glass is important. The glass warms so quickly that it is almost impossible to benchmark performance. Your controlled tests probably need to be run with the glass in the chilled environment/freezer.
• scraping the ice along the glass interface is quite different than cutting into the ice to get to the glass. Are these two different operation modes?

Pink: Folding litter
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The team has made a lot of progress since the last review, but there are a number of critical challenges that are yet to be resolved. Learning from the current model and then executing a redesign is an important next step.

Overall, it seems like two planar trusses were designed, without considering out-of-plane or 3 dimensional effects (torsion, side loading). Also the joints pivot in the plane of the side trusses, so the trusses were not as stiff as they could have been.

It is important to design the truss as an integrated, 3 dimensional structure. The backboard might also help to complete the structure.

Some additional thoughts follow:

• a core proposition is portability. Thus, the backpack/carrying package is an important aspect of the design. If this is awkward and cumbersome the design looses credibility.
• many revievers were not convinced that the assembly time was unimportant. Assembly certainly could be made easier. Can tensile members run through the tubes so that it is easy to put things together correctly?
• can the joint/latch types be somewhat standardized? Fewer things for the user to learn, and fewer elements for the development team to engineer.
• positive feedback is needed to know when joints are properly assembled.
• tensile members running through joints that provide a compressive pre-load on the joint can significantly stiffen and strengthen a structure. Perhaps cable/tensile elements can be part of the structure.
• the design cannot have catch points that will get snagged on items when in use. Snagging cannot result in joints becoming un-latched and the structure collapsing.
• the backboard attachment is important because unlike other enclosed litters, the board could easily slide out of either end of the litter.
• many reviewers did not hear much about the design of the backboard.

Average prototype scores

The average scores out of 10, provided below, are based on prototype operation and the assessment viewpoints outlined in the technical review description. A higher score is better. Different instructors focused on different viewpoints. The data are averaged from scores provided by 32 reviewers.