(Clever title here)
Week Two: Low-Fidelity Prototyping

Our exercise for this week was to make low-fidelity prototypes that were meant to simulate a numbing agent for a needle. The general goal of this numbing agent would be to modify a syringe in some fashion so that a doctor or nurse could easily use the modification to numb a patient before giving them an injection. More specific goals included having the motion of administering numbing method of choice to be easily integrated with the injection motion.

I began by brainstorming methods of causing numbness, and then breaking these sub-categories down into smaller blocks. For example, one method of causing numbness would be applying coolness, which could be achieved by evaporative cooling, administration of ice or another chilled object, or an endothermic reaction. A quick snapshot of my brainstorming page is shown below, largely for entertainment rather than educational purposes.

The main categories of methods of numbing that I eventually decided to work with were:

• application of cold
• disabling of surrounding nerves
• topical numbing agents

I then broke some of these categories into smaller categories, which I then used as a basis for formulating design ideas.

• application of cold -> endothermic reaction, ice/chilled external device, evaporative cooling
• disabling of surrounding nerves -> electrical shock, application of pressure, “slapping” motion
• topical numbing agents

I then used these subcategories as a basis for brainstorming prototyping ideas, shown below.

Two of these ideas dealt with the idea of temporarily disabling the nerves surrounding the injection site. The first category involves the application of a small electric shock to the patient’s skin, temporarily stunning the skin nerves so that the patient is unable to feel the injection that follows. The second category involves limiting blood pressure to the injection site by using a pinching or clamping motion, again temporarily disabling the nerves so that the patient does not feel the injection.

The first half of the page concerns ideas regarding administration of a small electrical shock. I experimented with several methods of safely administering electrical shock, including using the injection needle as a means of conducting voltage from an external source. I also experimented with several methods of charge distribution, including prongs to deliver charge as well as a small, washer-like device that could deliver charge to all points around the injection site. Finally, I considered packaging small, charged non-conductors that could deliver small amounts of static charge upon contacting a conductor, such as skin. Because doctors or nurses giving injection must wear gloves, the first conductor that will come into contact with these small, pre-sealed charged packets should be the patient’s skin. These ideas largely seemed promising, although it was difficult to determine if they would actually function outside of the low-fidelity prototyping scenario.

The second half of the page concerns ideas regarding pinching the skin around the injection site so that the affected area suffers from temporarily decreased bloodflow, effectively numbing the patient. Many of the methods of pinching here attempted to piggyback off of the downward motion used during an injection–when the doctor presses the plunger to commence the injection, the clamped area will tighten. However, many of the clamping devices that used the downward motion of the plunger were overly complex and likely would not work or would be difficult to manufacture. Some of the other configurations, which included a simple clamp attached to the base of the syringe, seemed overly simple in contrast, although they showed promise.

The next set of ideas concerned the application of a numbing liquid, likely a gel. The first method involved the application of a topical numbing gel. Many of these ideas seemed to be overly complicated–an ideal solution would be to supply doctors with blister packs of numbing gel, which could then be placed easily on the injection site.

The second half of this page demonstrates methods of using endothermic reactions to create cold. Methods here include mixing two packets of different chemicals (chemistry isn’t my strong suit, and research didn’t quite happen to the extent required to teach me the chemistry I would’ve needed) to cause an endothermic reaction, which would then chill an object. In some designs, the needle itself would be chilled, numbing the injection site and the needle simultaneously; in other designs, areas near the injection site would be numbed before the injection takes place.

The final design subcategory concerned, somewhat counter-intuitively, the application of a short snap of pain. After extensive testing, I did confirm that slapping oneself did greatly lessen the amount of pain from a “shot,” simulated by being poked by a pencil. As such, many of the designs here focus on releasing a stored energy. Some of these methods include the releasing of elastic energy (stored in rubber bands or some similar elastic device), a spring to create slapping, and a tightly-coiled flywheel.

Many of the ideas brainstormed during this stage were ridiculously impractical, but amusing to consider nonetheless. Ultimately, I selected five of these ideas for low-fidelity prototyping.

The first low-fidelity prototype is meant to simulate an electrical nerve block, shown below:

The white portions represent charged, non-conducting, flexible materials, likely made out of a type of plastic. The plastic can store a charge on its surface for a relatively large amount of time, assuming it is kept in a sealed, non-conducting area. The charged claw is then attached to the base of the needle using the area marked in green; a doctor or nurse can then touch the charged prongs to the patient’s skin, temporarily stunning the skin around the injection site due to the small, static shock. This shock causes minimal pain and would hurt no more than touching a statically-charged doorknob on a winter day, although it would greatly decrease the pain of injection. It is also important to note that this method only works if the doctor or nurse uses gloves, as the glove material will insulate the doctor or nurse’s hand and prevent them from accidentally discharging the prongs. A full view of the charged prongs attached to the needle is shown below:

The second prototype involves the use of clamping the injection site so that the patient loses bloodflow for a limited amount of time in the injection area. Limiting bloodflow to the injection site limits the amount of pain that the injection can cause, thus simulating numbing. The final design for the clamping mechanism is shown below.

The clamp is attached to the base of the syringe using the green attachment device, shown above. The skin around the injection site can be easily clipped into place, temporarily cutting off bloodflow to the injection area. Note that some issues with maneuverability of the syringe are encountered, as the clamp must, by necessity, hold the skin in place; however, these losses in maneuverability seem fairly minimal. A photo of the clamping mechanism attached to a model syringe is shown below:

Ultimately, I decided that the final solution involving topical numbing agents would always be more complex than simply supplying individually packaged topical numbing agents and asking the doctors or nurses to apply the numbing agent by hand. As a result, I ultimately created two low-fidelity prototypes for the endothermic reaction.

As previously mentioned, the specific chemicals for these endothermic reactions has not been decided. I am not witty enough to give a valid explanation outside of my insufficient knowledge of chemistry, but the two chemicals are shown with a pink packet and a yellow packet, shown below.

The first of the endothermic low-fidelity prototypes uses the syringe needle itself as a means of conducting cold (or, more accurately, conducting away heat). The chemical packets are wrapped together into a single, small, cylindrical package

This orientation greatly maximizes the amount of surface area covered by the packets of chemicals. The packet of chemical is then pierced using the needle of the syringe itself, allowing the two chemicals to mix and triggering the endothermic reaction. This then chills the entire length of the needle, as shown below:

The second endothermic reaction involves placing the two packets of chemicals on the surface of the injection site. This allows for maximum area of cooling provided by the reaction, shown below:

The seal between both chemicals is first broken by the nurse or doctor, triggering the endothermic reaction. Then, as the mixture begins to cool, the packet is placed on the patient’s skin, cooling it. The needle of the syringe then is placed through the two springs and the plastic cuff (taken from the water guns found in the low-fidelity prototyping cart) and injected directly through the packet, minimizing the delay time between the placement of the packet and the receiving of the injection. The spring allows for the packet to sink down as the syringe is pressed inward, compensating for motion needed to press the needle inward.

The final method of numbing involves giving the patient a sharp sting, alleviating the longer pain of the injection that follows. This device operates by releasing the stored energy in an elastic, which provides a sharp snap upon release.

The device is attached to the syringe using the green attachments, which are built to fit snugly around the base of the syringe. When the doctor wishes to numb the patient, he should release the rubber band by pressing on the clip near the top of the device, allowing the rubber band to snap near the base of the needle, where the injection site is. This then numbs the patient temporarily, allowing for the injection to take place. The released rubber band mounted properly onto the syringe is shown below:

Conceivably, very few of these ideas would actually work. It was, however, very fun.