Musculoskeletal disorders, specifically low back pain, has been well documented andreported by astronauts throughout the space exploration era. Statistics from astronautmemoirs states that 52-68% of astronauts experience moderate to severe lower backpain after prolonged spaceflights. The main cause is atrophy in the paraspinal musclesof the lumbar region. No sufficient countermeasure exists in-flight currently and therehabilitation programs remain ineffective. This thesis presents the first attempt to designand develop a prototype robotic exoskeleton, actuated by pneumatic artificial muscles, asan active countermeasure in-flight where it will be utilised as an equipment for muscularhypertrophy and a supporting device for rehabilitation programs on Earth. It will bemanufactured by additive manufacturing methods for adaptability while remaining lowin weight.A thorough analysis of the spine and lumbar region as a biomechanical system wasmade. Appropriate assumptions was made to simplify the understanding of the complexsystem that is the human spine. The targeted muscles were: multifidus, erector spinaeiliocostalis and erector spinae longissimus. A force analysis of the human torso bendingin the sagittal plane was made, finding that the torques of the torso reaches 244 Nm.The complete exoskeleton design is presented with the parts that will be 3D-printed andthe working principle of the system. Thereafter an extensive model of the exoskeletonis established using Denavit-Hartenberg representation of manipulators as a serial linksystem. The model provides a fundamental understanding of exoskeleton and enablesthe possibility to simulate it accurately. The evaluation protocol for the validation testsis then presented. Active pressure will be tested at 0, 3 and 6 bar and loads of 5 and 11kg will be lifted.Subsequently the assembly, with all the hardware and software selected for the prototypeis demonstrated. Thereafter the results of the evaluation tests are presented followed bya discussion of the results; anomalies, faults and challenges are subjects discussed. Thediscussion concludes that the exoskeleton shows potential for both supporting the motionin a rehabilitation use and enabling muscular hypertrophy in the lumbar region for theresistive tests. Although an extensive heavy-duty evaluation needs to be performed totruly validate the exoskeleton.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:ltu-88254 |
| Date | January 2021 |
| Creators | Häggman, Evert |
| Publisher | Luleå tekniska universitet, Institutionen för system- och rymdteknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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