The Artificial Bicep (Jess Herr)

Materials needed

Article - Robotic Brace Aids Stroke recovery

Each group needs:

• 6 rubber bands (a few different sizes)

• thin rope, 2.5 m

• string, .5 m

• scissors

• paper, 1 sheet

• Artificial Bicep Worksheet, one per student

• (optional) springs (may be expensive)

For the entire class to share:

• 1 20-Newton spring scale

• ruler, 12-inch or meter

Background

Students are introduced to how engineering closely relates to the field of biomechanics and how the muscular

system produces human movement. They learn the importance of the muscular system in our daily lives, why it is

important to be able to repair muscular injuries and how engineering helps us by creating things to benefit our

muscular health, movement and repair.

Engineers must understand how the body works and, in particular, how muscles function in order to assist medical

doctors in solving challenges with our muscular system. Biomedical engineers apply their engineering background

to design devices to help restore muscle functionality through the use of prosthetics that attach to existing limbs or

through the use of special machines to exercise muscles for strengthening and/or survival. Through biomechanics,

engineers assess the physical capabilities and limitations of the muscular system, with the overall goal of

improvement of health and quality of life.

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Procedure

1. Present the class with the biomedical engineering challenge for the day: To create a device to aid in the muscle recovery of a bicep by assisting it, therefore allowing it to rest more and recover sooner.

2. Hand each person a worksheet.

3. Divide the class into groups of two or three students each and remind them of the steps of the engineering design process (write the following steps on the class board): Ask, Imagine, Plan, Create, Improve.

4. Let the students know what materials are provided, and the criteria and tests for their devices.

5. Suggest to student teams that each design include a type of shoulder harness and hand harness made from the rope connected with pieces of string that are tied to rubber bands. For example:

• A shoulder harness might have two loops of rope connected, like a figure eight, so that one goes around the arm and the other goes around the chest (see Figures 1 and 2).

• A hand harness might also be created from rope made into a figure eight with one loop going around the middle finger and the other going around the wrist (see Figure 1).

• Use the rubber bands to connect the shoulder harness to the wrist harness so that they pull on the arm when it is straight.

1. Give the teams about five minutes to "ask" questions and "imagine" how they could solve the design challenge. Guide the groups to "plan" their designs on their worksheets. Approve student designs before permitting teams to obtain their materials.

2. Give students about 15 minutes to "create" their designs.

3. When the students are done, test their devices.

• To test the applied force of a device, have a student wear it, but keep the hand harness off. Then pull the hand harness down so that the rubber bands are as long as they would be with their arm extended. Then attach the spring scale to where the rubber bands meet the hand harness and measure the force being applied by the rubber bands. A stronger force means the less the bicep has to work to bend the arm. Have students record their team measurements on their worksheets.

• To test the distance the machine applies a force to the arm, have students wear their device and pull the hand harness down, similar to the last test. Then, place a ruler where the rubber bands attach to the hand harness. Slowly raise the hand harness until the rubber bands are no longer stretched. Measure the distance the rubber bands were stretched. The greater the distance, the longer the machine helps raise the arm. Have students record their team measurements on their worksheets.

1. Record the results on the board.

2. After seeing all the design ideas and how they all performed, have students complete their worksheets and revisit their drawings to re-design improved versions.

3. Conclude by having each team create and perform an infomercial for their design as described in the Assessment section.

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Questions

• Explain why biomedical engineers are interested in the muscular system.

  • Biomedical engineers are people who blends traditional engineering techniques with the biological sciences and medicine to improve the quality of human health and life. Muscle injuries are a common source of immobilization and thus a great opportunity to design solutions to problems that may arise. By understanding the human body, engineers are able to design machines to help doctors and patients heal and repair damaged muscles

• Name some devices biomedical engineers have created to aid the muscular system.

  • Engineers have developed several machines to help muscle recover quickly. One of these pieces of equipment is an ultrasound device. Basically, an ultrasound device focuses sound waves (which we cannot hear) on the injured muscle providing deep muscle stimulation, which increases blood flow and promotes healing. The end result is a muscle that recovers more quickly than if it was left alone.

  • Biomedical engineers also help develop machines for people who are paralyzed. Paralysis is the loss of the ability to use part or all of the body. Biomedical engineers work on designing devices that can help undo the effects of paralysis. For example, engineers created a robotic brace to help stroke victims with resulting arm paralysis.

• Explain some specific injuries related to the muscular system.

  • • The most common soft tissues injured are muscles, tendons, and ligaments. These injuries often occur during sports and exercise activities, but sometimes simple everyday activities can cause an injury.

      • Sprains, strains, and contusions, as well as tendinitis and bursitis, are common soft-tissue injuries. Even with appropriate treatment, these injuries may require a prolonged amount of time to heal.

Photos

• Photos of Engineering Project

Figure 2: Example final biomedical design product. copyright

• Photos of real-life application of engineering Concepts

References

TeachEngineering.org