Introduction
Dentures are prosthetic devices constructed to replace missing teeth. Replacing lost teeth is good for health and appearance. Without this support, facial muscles will sag, making it harder to eat and speak properly. However, regular dentures cannot fully support someone’s mouth as they are not able to bite and chew as well as they used to. The food choices are also minimal as people cannot eat apples, carrots, almonds, peanuts, pork, steak, ribs, sandwiches, etc… We eat food by grabbing and tearing it with our teeth. This action pulls on the teeth and drawing on dentures will dislodge them. Eating the mentioned foods will take a lot of chewing, accompanied by a lot of pain, making it uncomfortable and discouraging people from wearing dentures entirely. Many dentures make it hard to live a normal and healthy life. Many people have expressed feelings about dentures making their life worse instead of improving and making them more confident. However, with our invention, Assisted Eating Dentures, people will not have to worry about giving up on certain foods, taking a lot of time to chew, or not being able to live a normal and healthy life. They can enjoy food and speak properly without pain and discomfort.
Innovations in effect that don’t work
As opposed to the original dentures, these Assisted eating dentures (AEDs) remove the difficulty of eating certain foods, foods that would typically be avoided entirely. However, one may ask, if it is so difficult to chew certain foods, instead of using AEDs, why can’t people just chop up and blend those foods to drink them? In essence, the blender is another innovation that can replace the function of these AEDs, and much more efficiently at that. To this, the counterargument can be put forth that AEDs are more convenient than blenders. This is because with AEDs, there is no arduous work put into chewing one’s food, as opposed to chopping up, for example, a steak or chicken, and trying to prepare/blend it into small enough and manageable pieces that one can eat it. Not to mention the fact that the act of cleaning the blender will produce more work for the individual. Even after one manages to blend the food product, the enjoyment will be far worse than chewing the food normally. This is because the act of chewing, and more specifically, texture, plays an important role in the way we perceive taste. For instance, “the thickness of some foods can affect their taste by slowing the rate of which the flavor and aroma exits the food. If that same food was melted into a liquid, however, it would taste much stronger” (“How Texture Affects Taste,” 2019).
Another example of innovations that do not work are over dentures. These are used for people who have lost most of their teeth and are held in place by dental implants. Dental implants are titanium fixtures, surgically inserted into the jawbone and take up to half a year to bond properly (“I Don’t Want Dentures,” 2019). If successfully implemented, over dentures are quite beneficial in the long run. “Since the over dentures are securely held in place, they stimulate the jawbone, which will slow down and even prevent any further bone loss from occurring” (“I Don’t Want Dentures,” 2019). However, over dentures do not work for everyone. They can be expensive, typically costing around $2500 for the dentures and $1000-$3000 per implant. At least 4-6 implants will put the cost upwards of $22,000 (Kitts, 2022). Additionally, most people are not comfortable with the invasive surgical procedure and the couple of months of discomfort that it takes for the implants to bond. On the other hand, AEDs require no surgery and are comparatively inexpensive, with the retail price being $1000.
Technical Description of Components
The linear actuator converts its motor’s rotary motion into linear motion. The actuators used in AED are micro linear actuators, which are the same as the standard actuator but minimized to fit inside the dentures. Figure 1 illustrates all 6 components of the linear actuator.
Figure 1
Note. Provided by progressiveautomations.com
Dentures are the main component of AED (Assisted eating dentures). They contain realistic gums made from acrylic and teeth made from porcelain. The dentures’ gums would be the ones connected to the actuator. The bottom set of teeth are connected as one unit and move upwards when the actuator pushes upwards. They also move downwards when the actuator retracts. Additionally, there are two 12-volt Toshiba replacement batteries placed inside the dentures to power each actuator. A radio frequency receiver placed inside the gums of the dentures is used to communicate with the remote controller. Figure 2 shows the general layout of dentures and where the actuator would be placed inside them.
Figure 2
Motor: the motor contains a rotor, a drive shaft, a stator, a cooling fan, drive shaft, terminal box, and stator windings. The motor can be seen in figure 1, adjacent to the lead screw and connected to the gearbox.
Gearbox: gears in the gearbox (figure 3) are used to reduce speed from the DC motor (rotary motion) and increase torque force (torque force converted to linear motion via lead screw). Lower gear ratio equals lower force, higher speed. For instance, a reduction ratio of 100:1 means for every 100 rotations of the motor, there will be 1 rotation of the final gear in the gearbox which is connected to the lead screw. 50:1 means lower force, higher speed. The lead screw (connected to the gearbox) then turns with a set number of turns per inch (TPI), which causes the linear motion of the actuator via the Acme drill nut. This function is used with the controller to reduce/increase stroke tempo. This means more force with lower speed and less force with higher speed (Bong, 2021).
Figure 3
“Gear box connected to Lead Screw”
Note. Image provided by progressiveautomations.com
Retract Limit Switch/Extend Limit Switch: Limit switches are safety mechanisms that stop the actuator when it reaches its limits. Without Limit Switches, the motor would continue rotating and burn out, causing mechanical failure. They also allow smoother stopping motion. How they work: normally, electricity from the power supply goes from the input connector to the motor to the limit switches, then back to the connector (Bong, 2021). This flow of electricity is in two directions, illustrated by figure 4.
Figure 4
“Normal movement of electricity in linear actuator”
Note. Provided by progressiveautomations.com
When the limit switch is touched by the drill nut, the limit switch activates and breaks the path of electricity via unidirectional diodes. These diodes allow electricity to flow in only one direction. For instance, when the extend limit switch is activated, electricity needed to extend the actuator is blocked off. Movement in the other direction is allowed, causing the retraction of the actuator. When the drill nut is no longer touching the extended limit switch, electricity is once again allowed in both directions (Bong, 2021).
Figure 5
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