MIRA University of Twente
Department of Biomechanical Engineering

CTW - BW

Afstudeeropdracht

Introduction

The tribology of skin plays an important role in many daily activities. Typically, the tribological studies on skin are related to cosmetics and the effects of skin care products, sports and medical applications. The hydration content of skin is an important parameter which has a large influence on its friction behavior, which can be experienced during a sport activity on a warm day where sweat causes the t-shirt to ‘stick’ to the skin. This phenomena also plays an important role in the development of pressure ulcers.

Figure 1 Example of a grade III pressure ulcer

Pressure ulcers are injuries to the skin and/or underlying tissue, as a result of sustained pressure and shear. The shear is a result of the frictional forces between skin and supporting surface. Higher frictional forces result in higher (more damaging) shear stresses.

Objective

The objective of this project is to further extend an existing tribometer with a climate chamber and motor driver for controlling the movement of the load cell. Experiments are to be carried out on subjects in order to study the acclimation time of skin and the effects of skin hydration on the frictional behavior.

Approach

Literature study

Development climate chamber

Development motor driving system

Experiments on subjects

Analysis of the results

Contact

If you are interested in working on this subject, please contact:

m.klaassen@utwente.nl

The role of posture in Scoliosis

The role of posture in Scoliosis

Validation of a Musculoskeletal Spine Model

Validation of a Musculoskeletal Spine Model

Measuring in-Vivo Spine Movement

Measuring in-Vivo Spine Movement

Aging Spine - Ontwikkelen van een FE model voor het simuleren van wervel fracturen.

 

Location:

Intern of extern (Universiteit Nijmegen)

 

 

Project:

Aging Spine

Supervisors:

Dr.ir. Jasper Homminga

Prof.dr.ir. Ton van den Boogaard

Prof.dr.ir. Nico Verdonschot

 

 

Starting date:

2012

Introduction

Osteoporosis (botontkalking) is een aandoening die zich kenmerkt door een lage botmassa en een afgenomen kwaliteit van het bot. Het resultaat van osteoporose is een zo sterkte afname van de sterkte van de botten, dat relatief normale belastingen (bv een misstap) al kunnen leiden tot een botbreuk. Alhoewel osteoporotische breuken overal in het lichaam voorkomen zijn wervelbreuken het meest frequent: elke 22 seconden een nieuwe wervelbreuk (wereldwijd).

Figure 1 – fractures vertebra

Assignment Introduction

Om beter te kunnen voorspellen welke patiënt een wervelbreuk gaat krijgen, om beter te voorspellen bij welke belasting de patiënt de breuk gaat krijgen, om beter te voorspellen wat het effect van bepaalde klinische behandelingen is, hebben we een goed model nodig van het faalgedrag van wervels.

Huidig FE-model van drietal wervels

Main Goal

Met deze afstudeeropdracht willen we een eindige elementen simulatie ontwikkelen, waarmee we fracturen kunnen voorspellen in gezonde en osteoporotische wervels. Om op die manier de fractuurkracht en de fractuur locatie te kunnen voorspellen.

Balroom - Effect of velocity on short range stiffness in the ankle joint

Location:

Twente University (also open for students from TU Delft)

Background

(Bio-)Mechanical engineering, Electrical engineering, Biomedical engineering or similar

Project:

Balroom

Supervisors:

Denise Engelhart (Twente, daily supervisor)

Alfred Schouten

 

Introduction

The mechanical behavior of a joint can be described by a (linear) musculoskeletal model of a human limb with intrinsic feedback due to the visco-elasticity of active muscles, and with reflexive feedback (length, velocity and force) of muscle afferents (muscle spindles and Golgi tendon organs).

Description: CrossbridgeMuscles behave as elastic springs during the initial strain phase, indicated as short range stiffness (SRS). Beyond a certain amount of strain the muscle demonstrates a more viscous behavior. The strain at which the muscle transits from elastic- to viscous-like behavior is called the elastic limit and is believed to be the result of breakage of cross-bridges between the contractile filaments.

Assignment introduction

In a recent study of the arm (de Vlugt, 2011) it was shown that the elastic limit, measured in vivo at the wrist joint, is depended on the speed of lengthening. Brief extension rotations were imposed to the wrist joint at four different speeds and at three different levels of voluntary torque. With closed loop system identification techniques (CLSIT), the elastic limit from measured joint angle and torque was quantified. The question now rises if the same behavior exists at the ankle joint. Furthermore, we want to know if CLSIT can be used to investigate the contribution of passive, active and reflexive components in SRS, so more insight can be gained in the underlying (patho-) physiology.

Objectives

The Bilateral Ankle Perturbator (BAP) consists of two small foot-size platforms driven by an electromotor, which can rotate around the ankle axis; therefore different ankle torques at different speeds can be set and the reaction can be measured over time. The aim is to investigate short range stiffness of the ankle joint using the BAP.

Methods

o

Literature review on mechanical behavior of a joint including short range stiffness

o

Study the effect of angular velocity on SRS using the BAP

o

Study the effect of joint torque on SRS using the BAP

o

Use system identification techniques to quantitative discriminate between the contribution of passive, active and reflexive components in SRS

o

Write a report in the form of a scientific paper

Further information

If you are interested in this assignment, please contact Alfred Schouten (a.c.schouten@tudelft.nl) or Denise Engelhart (d.engelhart@utwente.nl) for further information.

Balroom - Effect of soft support surfaces on balance

Location:

Twente University (also open for students from TU Delft)

Background

(Bio-)Mechanical engineering, Electrical engineering, Biomedical engineering or similar

Project:

Balroom

Supervisors:

Denise Engelhart (Twente, daily supervisor)

Alfred Schouten

 

Introduction

Postural instability and falls are common and devastating features of ageing and many neurological, visual, vestibular or orthopedic disorders. Current management of these problems is hampered by the subjective and variable nature of the available clinical balance measures.

Steadiness during standing and walking on soft support surfaces decreases with age and is a potential risk factor for unexpected falls in elderly subjects. Therefore older adults undergo functional balance training that is specifically oriented to improve steadiness of Centre Of Pressure (CoP) while standing on compliant surface (CS). Nevertheless, looking only at CoP and Centre of Mass (CoM) sway does not really tell us if proper compensation strategies are used. It is expected that as only ankle torque is not sufficient to compensate for the imbalance, hip strategy should be used.

Assignment introduction

The Bilateral Ankle Perturbator (BAP) is developed to perturb the human balance and to investigate the underlying mechanisms of balance control. It consists of two small foot-size platforms driven by an electromotor, which can rotate around the ankle axis. Hereby the proprioceptive information coming from the muscles is disturbed and the human balance is challenged. The actuation of the BAP so far is only used in position mode, but there are possibilities to extend the application, using force mode.

Force perturbations create the possibility to manipulate the stiffness of the support surface, similar to having participants stand on foam. Using an actuated apparatus has the advantage of being able to manipulate the stiffness in a very controlled fashion and as such to investigate adaptation of human balance control to stiffness of the support surface.

Objectives

The aim is to optimally control the BAP in force mode and investigate the use of ankle and hip strategy and sensory reweighting in healthy subjects.

Methods

o

Literature review on balance control in older adults and functional training on compliant surfaces

o

Extend the usability of the BAP with force control

o

Investigate balance compensation methods, like ankle and hip strategy on compliant surfaces using system identification techniques

o

Investigate sensory reweighting on compliant surfaces using system identification techniques

o

Write a report in the form of a scientific paper

Further information

If you are interested in this assignment, please contact Alfred Schouten (a.c.schouten@tudelft.nl) or Denise Engelhart (d.engelhart@utwente.nl) for further information.

Balroom - Time variant ankle stiffness

Location:

Twente University (also open for students from TU Delft)

Background

(Bio-)Mechanical engineering

Project:

Balroom

Supervisors:

Denise Engelhart (Twente, daily supervisor)

Alfred Schouten

 

Introduction

Postural instability and falls are common and devastating features of ageing and many neurological, visual, vestibular or orthopedic disorders. To unravel the underlying pathophysiological mechanisms closed loop system identification techniques (CLSIT) are used. The advantage of CLSIT is that it ‘opens the loop’ of a system in which the controlled variable (body sway) is fed back to the control variable (torque due to muscle activations). The underlying (patho) physiological mechanisms of balance control can be identified, leading to standardized and unbiased results.

Assignment

The mechanical behavior of a joint can be described by a (linear) musculoskeletal model of a human limb with intrinsic feedback due to the visco-elasticity of active muscles, and with reflexive feedback (length, velocity and force) of muscle afferents (muscle spindles and Golgi tendon organs). Nevertheless, the visco-elastic properties of for instance the ankle joint depend on the position of the joint and therefore vary during movement. We want to investigate this non-linear behavior using Time Varying CLSIT and see how the physiological parameters change over time.

Objectives

The Bilateral Ankle Perturbator (BAP) consists of two small foot-size platforms driven by an electromotor, which can rotate around the ankle axis; therefore different angles of the ankle can set and reaction measured over time. The aim is to develop novel techniques to identify TV ankle stiffness using the BAP.

Methods

o

Literature review on mechanical behavior of a joint including different feedback loops and important physiological parameters.

o

Develop new techniques for time (parameter) varying system identification.

o

Study the effect of non-linear movement of the human body (slow adaptation) on parameter estimation with the new TV CLSIT

o

Study the effect of non-linear perturbation amplitude (sudden adaptation) on parameter estimation with the new TV CLSIT

o

Write a report in the form of a scientific paper

Further information

If you are interested in this assignment, please contact Alfred Schouten (a.c.schouten@tudelft.nl) or Denise Engelhart (d.engelhart@utwente.nl) for further information.

Balance control and corticospinal circuits - Cortical contribution in balance control

Location:

Twente University

Background

(Bio-)Mechanical engineering

Project:

Balroom, Corticospinal circuits

Supervisors:

Denise Engelhart, Floor Campfens

Alfred Schouten, Herman van der Kooij

 

Assignment introduction

This project is the intersection of two research projects: balance control and identification of the corticospinal circuits. The aim is to quantify cortical contributions in balance control using EEG recordings and recent advances in system identification.

Despite the ease at which healthy people maintain their balance, maintaining an upright posture requires continuous control of posture. The human body is essentially an inverted pendulum that would fall over when confronted with the slightest deviation from a perfect upright position. At the University of Twente, within the Laboratory of Biomechanical engineering, techniques are developed to unravel specific aspects of balance control, such as the integration of sensory information and the contribution of different joints (left and right ankle and hip joints). The role of the cortex has remained unexplored so far.

The cortical involvement in planning and controlling a motor task can be quantified using coherence between the EEG (brain) and EMG (muscle) signals: corticomuscular coherence (CMC). CMC is a measure for the synchronization between brain activity and muscle activation. Recent experiments at the University of Twente revealed that the addition of perturbations enhance corticomuscular coherence, making it an even better measure to quantify the involvement of the cortex in a specific task. As perturbations are necessary to study a closed loop system such as balance control, we want to combine both worlds and study the cortical involvement in balance control using perturbations.

Aim

The aim of this master assignment is to explore the use of EEG measurements and corticomuscular coherence to quantify cortical involvement in balance control

Tasks

-

Literature review on cortical involvement in balance control

-

Testing of various perturbations and EEG analysis techniques, including corticomuscular coherence

-

Performing final experiments in a group of healthy volunteers

-

Writing of a final report in the form of a scientific research paper

Further information:

If you want to participate in this project and take on a challenging master assignment, please contact Floor Campfens and/or Denise Engelhart

Also students who still need to find an (international) internship are invited to respond to this master assignment, we can help you look for an internship which can complement the master assignment.

Robot Aided Rehabilitation – Design of a supination actuator

Location:

Twente University

Background

(Bio-)Mechanical engineering

Project:

Robotic Aided Neuro rehabilitation of arm and hand functioning – MIAS-ATD

Supervisors:

Ard Westerveld (daily supervisor)

 

Introduction

The MIAS-ATD project aims at integrating robotics with electrical stimulation. Integrating training of the hand makes it possible train functional meaningful movements and motivate patients during therapy. Grasping objects is part of multiple functional movements in daily life. It becomes difficult or even impossible to grasp for a large number of patients (like spinal cord injury, hemiplegia due to stroke, Duchenne muscular disease, Multiple Sclerosis and many others).

For a reasonable amount of objects grasped in daily living, the orientation of the hand is very important (think of grasping a cup with hot coffee, for instance). Some patients (like most stroke survivors) often have difficulties with their control of supination movements. To help these patients regain functional independency, assistance of supination movements during therapy is desirable.

Objective

Assisting supination with surface electrical stimulation is not possible, because the supinator muscle lies deep in the muscle layer of the forearm, below other muscles. Therefore mechanical assistance of this movement is needed if the patient is incapable of controlling their supinator muscle sufficiently. The goal of this assignment is to design such a device (actuator) which can provide the desired assistance during the grasp of objects.

Approach

·

Browse literature for existing systems

·

Identify key requirements

·

Write specifications

·

Design actuator(s)

·

Develop prototype

·

Develop test setup

·

Test final design

More information:

Ard Westerveld, MSc

Room HR W215

Email: a.j.westerveld@utwente.nl

Robot Aided Rehabilitation – Design of a smart coffee cup

Location:

Twente University

Background

(Bio-)Mechanical engineering

Project:

Robotic Aided Neuro rehabilitation of arm and hand functioning – MIAS-ATD

Supervisors:

Ard Westerveld (daily supervisor)

 

Introduction

Grasping objects is an important function in daily life. It becomes difficult or even impossible to grasp for a large number of patients (like spinal cord injury, hemiplegia due to stroke, Duchenne muscular disease, Multiple Sclerosis and many others). Sufficient electrical stimulation (ES) of finger flexor and extensor muscles, together with the thumb musculature, can support the natural grasping function. ES can help these patients to become more functionally independent and regain manual dexterity.

In the past, several authors have claimed functional meaningful exercises to be more successful for rehabilitation than other exercises. The manipulation of objects is such a meaningful exercise occurring often in daily life.

To be able to effectively train the affected hand, it is necessary to know how much assistance should be applied by the electrical stimulator. Therefore, the performance of the subject needs to be evaluated. In addition it is useful to monitor the improvement of the patient.

Objective

To combine both the measurement of performance and the functional meaningful training, an instrumented object is needed. The goal of this assignment is to design and evaluate such an instrumented object.

Approach

·

Browse literature for existing systems

·

Identify key requirements

·

Write specifications

·

Generate concepts

·

Choose best concept

·

Detail concept

·

Develop prototype

·

Develop test setup

·

Test final design

·

Write thesis

More information:

Ard Westerveld, MSc

Room HR W215

Email: a.j.westerveld@utwente.nl

Scoliosis Correction - Ontwikkelen van een FE model van de buikholte.

 

Location:

Intern

 

 

Project:

Scoliosis Correction System

Supervisors:

Dr.ir. Jasper Homminga

Dr.ir. Gerdine Meijer

Prof.dr.ir. Ton van den Boogaard

Prof.dr.ir. Bart Verkerke

 

 

Starting date:

2012

Introduction

Scoliose is een drie-dimensionale vervorming van de wervelkolom, die het meest frequent is in adolescente meisjes. Hoewel veel risicofactoren voor het ontstaan en de progressie van scoliose bekend zijn, is de werkelijk onderliggende oorzaak nog onbekend.

Van achteren bekeken heeft de scoliotische wervelkolom een S- of C-vorm. Deze zijwaartse vervorming gaat samen met een axiale rotatievervorming. Bij ernstige vormen van scoliose komen de longen en zelfs het hart in de verdrukking. In milde vormen van scoliose wordt de scoliose behandeld middels een korset. Ernstige vormen worden behandeld door de wervelkolom recht te trekken met behulp van schroeven en metalen staven.

Figure 2 – scoliotic spine

Assignment Introduction

Om de behandeling van scoliose met bestaande en nieuw te ontwikkelen methodes te verbeteren is het noodzakelijk dat we een goed model hebben van de wervelkolom met alle structuren die van invloed zijn. In het recente verleden hebben wij daarom een FE-model (in Marc) ontwikkeld van de complete 10-jarige wervelkolom met ribbenkast.

Dit model moet nu uitgebreid worden met een representatie van de buikholte en de daar aanwezige druk. Uit metingen in mensen is bekend dat deze buikdruk een groot effect heeft op de werking van de wervelkolom in de romp. In vrijwel alle momenteel beschikbare modellen wordt de buikdruk echter of genegeerd of (te) sterk vereenvoudigd gemodelleerd.

Main Goal

Met deze afstudeeropdracht willen we het bestaande eindige elementen model van een 10-jarige romp completeren met een correcte representatie van de buikdruk.

Description: Ribcage_3DDescription: Biobag_3D

Huidig en toekomstig (?) FE-model van een romp

Spine loading after fixation on a spine board

Location

Twente University

Background

Mechanical engineering, BioMedical engineering

Project

-

Supervisors

Bart Verkerke

Ton van den Boogaard

Edsko Hekman (daily supervisor)

 

 

INTRODUCTION

One of possible injuries after an accident is fracture of one or more vertebrae. If spinal damage is suspected, victims will generally be placed onto a “Spine Board”, which basically is a rigid board. By strapping the patient on this board an attempt is made to immobilize the spine. The patient remains strapped to the spine board until after an MRI or CT-scan of the spine has been made. Not only is this very uncomfortable, but also there is discussion among experts about whether strapping the patient to a flat rigid board is beneficial to the patient or detrimental instead. Experience of ambulance personnel as well as some reported clinical evidence suggests the latter might be the case.

A first step to improve this situation is to provide a more anatomically shaped spine board. This has been the topic of a Bachelor assignment, and has resulted in the “Scoop 'n Runner”, shown in the figure. However, it still remains unclear whether strapping the patient down is beneficial or the opposite.

ASSIGNMENT

Your assignment will be to perform a Finite Element Method (FEM) analysis of the system consisting of spine board, human torso, and straps.

METHODS

Steps that are to be taken include:

- review relevant literature, interview ambulance staff and/or other sources

- make a model of the spine board and straps

- adapt the spine model in our group to suit this analysis

- determine “typical” spine damage situations, and include these in the spine model

- determine the appropriate loading situation and calculate the effect on the spine

- give recommendations on things such as location of the straps, tension, material stiffness and anything you can think of that improves the situation.

FURTHER INFORMATION

More information about this project can be obtained from Edsko Hekman.

VirtuRob - Evaluation of the Limpact Exoskeleton.

 

Location:

Intern

 

 

Project:

VirtuRob project

Supervisors:

Dr.ir. Herman van der Kooij

Dr.ir. Arno Stienen

Dr. Edwin van Asseldonk

Ir. Alexander Otten (contact)

 

 

Starting date:

Januari 2012

Introduction

Stroke is the leading cause of disabilities in Western civilizations. The treatment of stroke patients is labor intensive and strongly dependent on the best-practice opinion of the rehabilitation center or the individual therapist. In the last decade, several therapeutic devices have been developed by research groups from around the world, which have made the therapy less labor intensive and provided the therapists and scientific community with more objectively gathered measurements. Unfortunately these devices are also still struggling to deliver significant functional improvement over regular therapy.

The Active Rehabilitation Project wishes to resolve the question if robotics can actually improve the functional recovery of upper limb function of stroke patients. And if so, how to achieve the optimal results. The Limpact is a robotic upper limb device that will be used for diagnostics in order to reach these optimal results. By actively controlling the joint axes of the shoulder and the elbow, the identification and training possibilities for persons with neurological disorders are unique compared to current devices.

Figure 3 - Current state of the Limpact exoskeleton (courtesy of our technician Wouter Abbas)

Assignment Introduction

The Limpact is just recently operational and has never been tested for which is was built namely for motor learning tasks. The next step is to make the robot human friendly and to test it with healthy subjects, before it can be used on stroke patients.

Main Goal

An experiment needs to be designed in order to evaluate the exoskeleton. The main focus of the evaluation is the ability for the subject to move natural (zero impedance mode) and the exoskeletons usability in motor learning tasks. Points of interest are the “feel” when used in haptic VR environments and the human-machine interaction.

Tasks

·

Literature study on the use of rehabilitation robotics used in motor learning tasks,

·

Define an experiment (task(s) and goal(s)) using the Limpact exoskeleton,

·

Design the impedance controller, VR environment and data evaluation tools,

·

Perform the experiment in healthy subjects,

·

Evaluate the results

·

Write a thesis.

More information

ir. Alexander Otten

Room: HR W215

Mail: a.otten@utwente.nl

Figure 4 - Rendering of the Limpact exoskeleton in combination with VR (courtesy MOTEK Medical)

TLEMsafe – Quantification of muscle energy consumption using PET scans

 

Location

Rehabilitation Department/Orthopedics Department/ Nuclear Medicine Department

Radboud University Medical Centre

Description: RUNMC_logo.jpg

Description: D:\sjoerd\pictures\logo_MAT.jpg

Project

Project page

Supervisors

ir. Sjoerd Kolk (contact S.Kolk@reval.umcn.nl)

prof. dr. ir. Nico Verdonschot

dr. ir. Eric Visser

Starting date

June 2012

Introduction

Positron Emission Tomography with Computed Tomography (PET/CT) has recently been discovered to be a valuable tool in the measurement of muscle energy consumption. After injection of radioactively-labeled glucose (18-Fluorodeoxyglucose, a ‘tracer’), the muscles take up the glucose tracer to replenish their energy supply. The total accumulation of this tracer in the muscles can be detected with this technique. If the tracer is injected during a prolonged period of walking, the energy consumption of each lower extremity muscle can be measured highly accurately. The purpose of finding these muscle energy consumption values is to validate musculo-skeletal models of the lower extremity. This assignment is part of the ‘TLEMsafe’ project. In this project, the main overall goal is to improve the safety and predictability of orthopedic interventions of the lower extremity. We do this by creating subject-specific musculo-skeletal models (based on MRI scans) in which a surgery can be performed virtually. For this research, we used a brand-new PET/CT scanner at the Nuclear Medicine Department. This scanner is absolutely state-of-the-art (was installed November 2011) and offers the best possible imaging quality in the world.

Description: slice_detection22.bmp

Description: RUNMC_PET_ROI.png

Example CT scan.

a: Example of automatic image morphing of one MRI scan on top of another.

b: PET image, overlaid on a CT image. The lighter areas indicate high glucose uptake, and thus, high energy consumption in that muscle.

Objectives

We want to find the energy consumption of each whole muscle of the lower extremity during walking. This data will be of extremely great value for validating musculo-skeletal models. You will use state-of-the-art image analysis software (Materialise) to perform semi-automatic registration of PET/CT and MRI scans of 10 healthy subjects (already available). You will work in close cooperation with three departments in the RUMC and with Materialise (from Leuven, Belgium).

Further information

We seek a master student in Biomedical Engineering, Technical Medicine, Medicine or Biomedical Sciences who is interested in the musculo-skeletal system, and using state-of-the-art imaging and analysis techniques.

Design of a haptic measurement device

 

Location:

Intern or Extern (Moog Nieuw Vennep

 

 

Project:

Lopes

Supervisors:

Jos meuleman (contact)

 

 

Starting date:

asap

Introduction

Haptic devices interact physically with humans. User force is read as input, the device displays a force to the user in order to achieve haptic feedback. The applications vary from simulating virtual environments to assistive devices, from fingergrip devices to force driven leg orthoses. Different applications require different haptic performance. Yet suitable haptic performance measures are rare.

Objectives

Develop, design and build a measurement device that replaces the human in haptic systems, such as the HapticMASTER, series elastic actuators for Lopes and Limpact, in order to quantify the haptic performance of the haptic system.

Methods

·

Literature study: Identify haptic performance criteria. Focus on human perception

·

Select haptic performance measures define how they can be quantified in a protocol (virtual collisions, free air movement etc)

·

Design the device and controller

·

Build the device

·

Run the protocols on haptic systems

Further information

If you are interested, please contact Jos Meuleman (j.h.meuleman@utwente.nl)

Simulating haptic performance of force controllers

 

Location:

Intern

 

 

Project:

Lopes

Supervisors:

Jos meuleman (contact)

 

 

Starting date:

asap

Introduction

Haptic devices interact physically with humans. User force is read as input, the device displays a force to the user in order to achieve haptic feedback. The applications vary from simulating virtual environments to assistive devices, from fingergrip devices to force driven leg orthoses. Different applications require different haptic performance. Yet suitable haptic performance measures are rare. Why do force feedback devices often not feel as good as they promised?

Objectives

Simulate force controlled devices and quantify their haptic performance. Identify the critical parameters.

Methods

·

Literature study: Identify haptic performance criteria. Focus on human perception

·

Categorize haptic requirements by application area

·

Collect and assemble virtual models of force feedback controllers (series elastic actuator and admittance control)

·

Update the virtual models with friction, torque ripple etc

·

Simulate haptic performance of the models

·

Sensitivity analysis to find the critical parameters of the controller

Further information

If you are interested, please contact Jos Meuleman (j.h.meuleman@utwente.nl)

haoA lab-on-a-chip system to determine the effect of mechanical signals on cells

 

Location:

Intern/Extern

 

 

Project:

Tissue Biomechanics

Supervisors:

Dr. ir. Jeroen Rouwkema

 

 

Starting date:

As soon as possible

Introduction

In the field of bone tissue engineering, one tries to engineer bone tissue in a laboratory environment for scientific or medical (implantation) purposes. For this, cells such as mesenchymal stem cells isolated from the bone marrow and biomaterial scaffolds are generally used. Nowadays, mechanical loading regimes are already used in tissue engineering to enhance cell differentiation and extracellular matrix production. However, not enough data are available about the exact cellular response to mechanical signals. A lab-on-a-chip based system has been developed to screen for the combined effect of surface strains and shear stresses on cells. The current system however generates only equibiaxial strains. Various anisotropic strain profiles can be easily generated by changing the shape of pillars used to generate the strains.

Objectives

To generate new strain profiles by modifying a lab-on-a-chip system being used to determine the effect of mechanical signals on cells.

Methods

The aim of this project will be to modify the current device design to generate new strain profiles. The student will:

·

Design an array consisting of pillars with different shapes to generate anisotropic strains.

·

Use Finite Element modeling (ANSYS) to model the strains resulting from the array of pillars.

·

Fabricate the array and determine the actual strains using microscopy.

·

If time permits, study the effect of these strains on human mesenchymal stem cells.

This project will be performed in collaboration with BIOS, The lab-on-a-Chip group.

Further information

Jeroen Rouwkema

Horstring W200

053 489 2892

j.rouwkema@ctw.utwente.nl

Design of a control method and testing of the knee simulator

 

Location:

Extern

 

 

Project:

Knee Tester

Supervisors:

Prof. dr. ir. N. Verdonschot

ir. E.E.G.Hekman

dr. ir. A.H.A. Stienen

 

 

Starting date:

Immediately

Introduction

At first sight the human knee seems to be a fairly simple hinge joint. However, a closer look reveals that the joint is a complex system of three bony parts. cartilage and ligaments, lubricated in a mechanism which is still not completely understood, and actuated by a number of muscles.

At the orthopaedic lab of the University Medical Centre Nijmegen (UMCN) the function of the healthy knee, as well as the function and performance of implants are studied both in silico and in vitro. These studies, apart from giving scientific insight, are aimed at the development of new or improved surgical procedures and implants.

To support this research, a new knee tester has been designed (Figure 1). Partners are the UMCN, UT and BAAT (a company which develops medical technology). The new tester must enable the researcher to impose functional movements under loading on cadaveric knees. Construction of the hardware will be carried out by a student from SAXION, under supervision of BAAT. The control of the tester remains to be developed, implemented, and tested in practice.

Description: A description...

Figure 1: design drawing of the new knee tester

Objectives

Your assignment will be to develop a control system for the actuators. Data taken from known literature and simulation (Anybody) are to be used to perform functional movements on a knee specimen.

Methods

Steps that are to be taken include:

- review relevant literature, get input from the other partners e.g. the other student working on this project

- translate the desired loading profile into force or displacement profiles for the actuators.

- determine the desired control method

- implement the method in Matlab

- test the total system in a pilot experiment

- give recommendations on further development and improvements of the tester

Further information

Prof. dr. ir. N. Verdonschot HR W208 / UMCN

ir. E.E.G.Hekman HR W214

dr. ir. A.H.A. Stienen HR W214

Studying the stability of a bicycle and rider

 

Location:

Twente University

 

 

Project:

SOFIE

Supervisors:

BULSINK, V.E. MSC.

 

 

Starting date:

Immediately

General Introduction

This assignment is part of the project SOFIE (Slimme Ondersteunende FIEts/ Smart Assisted Bicycle). The goal of the project is to develop intelligent assistance devices for electric bicycles to help elderly or cyclists with disabilities and to improve knowledge about bicycle stability in general.

Complex interactions between the bicycle, the rider and the environment define whether the person feels stable on the bicycle. Computer simulations are used as a tool for studying the stability of the whole system.

Assignment Introduction

A multi-body model of the bicycle dynamics, tire-road contact and rider dynamics developed with the software Adams is used to simulate the behavior of the bicycle-rider system. The system is expected to be stable when the center of mass stays within certain boundaries.

Several ideas exists about how to improve the stability of the bicycle, these ideas can be tested using computer simulations.

Objectives

Define the most important parameters that influence the stability of the bicycle and test the ideas to improve the stability.

Methods

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Literature review on bicycle stability

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Sensitivity study of bicycle parameters on stability (and possibly extend the definition of stability)

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Find optimal design of the bicycle

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Testing ideas (of assistive devices) to improve stability

Further information

For more information about the SOFIE-project see: www.mobilitylabtwente.nl/sofie. If you are interested in this assignment, please contact Vera Bulsink (vera.bulsink@utwente.nl) for more information.