Deans' stroke musings: Negative Stiffness in Compliant Shell Mechanisms

Changing stroke rehab and research worldwide now.Time is Brain! trillions and trillions of neurons that DIE each day because there are NO effective hyperacute therapies besides tPA(only 12% effective). I have 523 posts on hyperacute therapy, enough for researchers to spend decades proving them out. These are my personal ideas and blog on stroke rehabilitation and stroke research. Do not attempt any of these without checking with your medical provider. Unless you join me in agitating, when you need these therapies they won't be there.

What this blog is for:

My blog is not to help survivors recover, it is to have the 10 million yearly stroke survivors light fires underneath their doctors, stroke hospitals and stroke researchers to get stroke solved. 100% recovery. The stroke medical world is completely failing at that goal, they don't even have it as a goal. Shortly after getting out of the hospital and getting NO information on the process or protocols of stroke rehabilitation and recovery I started searching on the internet and found that no other survivor received useful information. This is an attempt to cover all stroke rehabilitation information that should be readily available to survivors so they can talk with informed knowledge to their medical staff. It lays out what needs to be done to get stroke survivors closer to 100% recovery. It's quite disgusting that this information is not available from every stroke association and doctors group.

Tuesday, May 14, 2019

Negative Stiffness in Compliant Shell Mechanisms

Don't just lazily tell us it can be done. DO IT! Your advisors should have made sure you made a working prototype.

Negative Stiffness in Compliant Shell Mechanisms

Title
Negative Stiffness in Compliant Shell Mechanisms: To develop a passive stroke rehabilitation device
Author Broshuis, Ab (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Precision and Microsystems Engineering)
Contributor Rommers, Jelle (mentor)
Herder, Just (graduation committee)
Ayas, Can (graduation committee)
Degree granting institution Delft University of Technology
Programme Precision and microsystems engineering
Date 2019-04-26
Abstract Present stroke rehabilitation devices for the arm are often difficult to use by the patient himself and cannot be used at home. A compliant shell mechanism could overcome the shortcomings of the current available devices. By the use of monolithic shell mechanisms a simple to use device can be designed, which can be made wearable. It would make it easier for stroke rehabilitation patients to do repetitive rehabilitation exercises at home. The focus lies on balancing the gravity during the lifting of the upper-arm. To achieve that a negative stiffness in the compliant shell mechanism is necessary. Negative stiffness arises when tape springs are bent and buckle for a short range of motion. Tape springs are thin-walled beams with a curved cross section. The short range of the negative stiffness limits the use for static balancing over a longer range of motion. In this project an analysis is presented on how the range of the negative stiffness can be increased by changing the geometry. The addition of longitudinal curvature to the tape spring results in a more gradual negative stiffness for a longer range of motion. It is shown why the addition of longitudinal curvature results in a more gradual and longer range of negative stiffness during the bending of shell.
Subject Compliant Shell Mechanisms
Negative Stiffness
Structural Instability
To reference this document use: http://resolver.tudelft.nl/uuid:c97d8ea4-18e2-4b2c-a8c1-c670f3437e4b
Embargo date 2019-10-01
Part of collection Student theses
Document type master thesis
Rights