Intelligent deformable shoes for people with feet defects
Edited BY: Wenhang Cao
Edit Date: 2019-08-13 06:17:02
Question:

Background

Foot defect includes a series of defects including flat feet, overlapping toes, diabetic foot and hallux valgus related to foot. People with these defects suffer from the pain or tiredness while standing with normal shoes on. Moreover, they also have a need to correct the defect with shoes in a certain shape corresponding to their feet’s. To help these people with foot defect, there are mainly three forms of footwear sold in the market, namely shoes, insole, and foot orthosis. Force on different parts of the wearer’s feet varies dramatically with the activities the wearer is conducting. But these existing footwears are always unable to change its shape according to the change of force on foot, which weakens the effect of them. Besides, as the wearer’s feet shape changes in the process of correcting, his old shoes are becoming more and more inappropriate, which means the he has to buy new ones continuously. Thus, the circumstances of people with foot defect are still difficult nowadays, which calls for a new product to help them.

Guidelines for students

In this assignment, students are required to work in groups, and each group will consist of 4-5 members. Setting professional roles for each member is essential. The assignments and detailed descriptions are as follows:

Assignments

Time-advised

Descriptions

Brainstorming

0.5 days

  • Each group is supposed to conduct a brainstorming, and in the end the group members should come to a clear object and think about a general solution.

Market research

1 day

  • According to the product design direction, students should do market research, including user model, market size and trend, and competitive analysis, etc.
  • The outcome of market research should be included in the final presentation. Try to use charts or other methods to visualize the results.

Product designing

1 day

  • The product to be designed is supposed to relieve at least two kinds of foot discomfort, such as flat feet, overlapping toes, hallux valgus, etc.
  • The products can target on some specific foot defects or the students can design a general product to relieve all kinds of foot discomfort.
  • It’s better to design a product requiring multi-discipline knowledge, such as medical science, electronic and information engineering, materials science, etc.
  • Explain all the materials to use, costs and so on. Consider the social feasibility, technical feasibility and economic feasibility of the final product.

Product realization

2 days

  • Implement the assignment according to the product design plan. Make a prototype using the materials available, or make an virtual demo of the product.

Presentation and assessment

 

1 day

  • The presentation should include the process of product designing and realization. The students are also required to explain the principles of their design and show the product structure in detail.
  • The form of presentation can be diverse, such ppt, video, and physical display.
  • The assessment including inter-evaluation among groups and among group members. After the presentation, each group will score other groups’ products and vote on the best. Meanwhile, the members of each group will rate their teammates on their behavior in the team.
  • The project evaluation will mainly base on four aspects: ①Product necessity ②Market readiness ③Innovation ④STEM interdisciplinary The range of the score is 1~5.

 

Assessment

 

Parts

Proportion of final grade

Formative ongoing assessment

Brainstorming

5%

Market research

5%

Product design

10%

Product realization

20%

Summative assessment

Group assessment

30%

Peer assessment

30%

 

Abilities that students would acquire

  • Communication skills.
  • Time management skills.
  • Specific technical skills
  • Multidiscipline knowledge
  • Information retrieval and evaluation skills
  • Positive attitude towards the challenge

Example

Product:

Our products are designed to ease walking discomfort for people with foot defects and to correct poor walking posture. In addition to these two main functions, we also set them up to collect data on health information of the host.

Market research:

Using correction shoes as keywords to search on amazon, over 1000 results can be found. It indicates that there is a large market in this field. The products sold in the market can be divided into three kinds namely shoes, insole, and foot orthosis. Mostly ranging from $9 to $150, these footwears are not expensive. On the whole, insole has wider user group, with the advantages of convenience and low price. However, there also exist complaints about it like it dose not stick to the shoe, the effect is not clear, etc. For the shoes sold at present, customers also complain about the ineffective result. Other complaints about correction shoes include uncomfortableness, limited styles. Foot orthosis are used less due to its high price and inconvenience. Besides, users of all these three kinds of footwears complain about is that they are not adjustable.

Totally speaking, the products pointed to help the people with foot defect sold at present do work to a certain degree. But users are still longing for a new product that is adjustable, comfortable and really helps.

How it works:

Power supply module charge for all the electronic and mechanical components. The product has sensors that measure and collect plantar pressure information, which would be processed and analyzed by the micro controller unit(MCU). The target shape of the built-in insole can be generated by device controlled by MCU instantaneously. Meanwhile, the detail information can be showed on the cellphone application by the Bluetooth module embedded inside. The structural diagram shows below.

Fig.1. Overall structure diagram

Product composition:

  1. The first layer: Removable/ comfortable insole
  2. The second layer: sensors, MCU, processor,Bluetooth , battery, mechanical modules array
  3. The third layer: Another layer of insole material

 

Fig.2.  Product composition

 

A.Collecting and analyzing the information of foot posture

1. Sensor : PVDF Membrane pressure transducer

  • Soft pressure transducer
  • Waterproof / low power dissipation/ quick response/ Wide detection range
  • Suitable for wearable devices.

Fig.3.  Sensor unit

PVDF Membrane pressure transducer belongs to polymer piezoelectric material. The material itself can be regarded as a capacitor. When external forces are applied on the surface of the membrane, the surfaces produce polarity. The output charge of the sensor can represent the change of the force acting on the sensing surface of the membrane.

2. Plantar pressure analysis

The force on the foot mainly comes from the contact between the foot and the ground. The analysis of the contact force on the bottom of the foot usually observes the characteristics of the temporal curve of the force. The distribution of plantar pressure can be generated by analyzing and comparing the force curves in different areas of the foot.

3. Insole shape adjusting

After the plantar pressure information is collected, the target height data of different mechanical device should be generated by MCU, according to the set pattern, either walking posture correction or remission of walking discomfort. And the height could be achieved by controlling the forward and reverse of the shaft structure distributed on the second layer.

Fig.4.  Shaft structure

B.Cellphone application

After collected and analyzed by technological parts, relevant information is transmitted to mobile phone user by Bluetooth module and showed on cellphone application. The functions of application includes:

  1. Measuring some basic information, such as frequency, distance, time, etc.
  2. Analyzing the foot posture.
  3. Collecting health data.

Fig.5. Cellphone application

 

Question Created By: Wenhang Cao
Creation Date: 2019-08-12 20:21:45
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