Portfolio Draft

Page 1

2020

BEIRUT, LEBANON

PORTFOLIO

TA R E K M A H M O U D


2020

TAREK MAHMOUD

ABOUT ME I grew up between France and Lebanon, countries that house a diversity of cultures. This heterogeneity has allowed me to develop the ability to understand and absorb complex and diverse contexts. My interest in determining how to use mechanical principles to analyze and design for the human body inspired me to pursue a bachelor's degree in Biomedical Engineering. I gained experience in a diversity of fields involving design, engineering, and finance and now aim to expand the skills I have acquired thus far by advancing my education in design.

Experience Installation Engineer

Karl Storz EMG

09/19 - 10/20

Bank Audi Private Bank

01/19 - 06/19

GM Architects

09/18 - 12/18

Groupe D3

09/17 - 10/17

Intro to Architectural Design

Rhode Island School of Design

06/18 - 08/18

BEng Biomedical Engineering

University of Surrey

09/15 - 06/18

Grand Lycee Franco Libanais

09/06 - 07/15

Investment Banking Intern Architecture Intern Automotive Design Intern

Education

French Baccalaureate

Softwares

Languages

Contact

Acrobat

Microsoft Office

Arabic

Arduino

e-mail

tarekcmahmoud@gmail.com

ANSYS

Photoshop

English

Matlab

phone

+961 3 087 419

AutoCAD

Rhinoceros V6

French

Python

Linkedin

linkedin.com/in/tarekcmahmoud

Illustrator

Solid Edge

InDesign

2


2020

TAREK MAHMOUD

TABLE OF CONTENTS

Introduction to Architectural Design

Architecture Individual Project Model Crafting Hand Drawing

P. 4 to 13

Biomedical Signal Processing

Data Analysis Individual Project Programming Case Study

P. 14 to 17

Hephaestus Hand

Prosthetics Group Project CAD Modelling Ergonomics

P. 17 to 29

3


IAD

2018

Introduction to Architectural Design

6 Weeks

After graduating from the University of Surrey, I took

Individual

part in a six weeks long architecture course at the

Summer 2018

Rhode-Island School of Design. I was motivated by

Rhode Island School Of Design [RISD]

the idea of expanding the human-centered design skills I had acquired, through my BEng projects, to the built environment. The course was split into two phases. The first focused on developing an abstract idea by translating it into physical models crafted with a chipboard. These models were then studied further to produce drawings and spatial concepts. The second phase aimed to transform the abstract concepts previously developed into a house designed around two characters, on a specific site in Providence, Rhode Island. These six weeks enabled me to develop an understanding of scales relating to the human body as a whole, rather than specific parts of it. Furthermore, I significantly enhanced my ability to craft models and objects by hand utilizing various sets of tools. 4


ABSTRACT MODELS

2018

IAD

The first task I was assigned was to construct self-supporting models shaped with respect to a guiding concept. Models were to be made using two types of chipboard cut-outs (planes) with a specified set of dimensions. Furthermore, they were to fit in a volume of five cubic inches. I was to produce a series of models composed of two to seven planes. These culminated in a single, final model made up of seven planes twice the size of all other pieces. I studied the notion of movement. I was inspired by the studies of human gait I had done during my undergraduate studies. My models attempt to capture the position of planes moving through space at different time intervals. This motion can be linear and predictable but also random, spreading across multiple planes of space.

5


2018

ABSTRACT MODELS

IAD

6


2018

FINAL ABSTRACT MODEL

IAD

7


2018

FINAL ABSTRACT MODEL

IAD

8


2018

FINAL ABSTRACT MODEL, SECTION DRAWINGS

IAD

Two section cuts through the final Seven plane model were drafted. Depth and shadows were represented by means of line work (Line Density & Line Weight)

9


2018

ABSTRACT SPATIAL FRAGMENTS

IAD

10


2018

FINAL HOUSE MODEL

IAD

The house sits on a hill. It was designed for two brothers. One is a novelist, and the other is a commercial airline pilot. Their respective lifestyles were strongly considered. The novelist spends the majority of his time working from home. On the other hand, the pilot is away for most days. The little time he has in his house is spent resting in-between trips. Three spaces make up the developed concept. One for the novelist, one for the airline pilot, and one that is shared between both characters. At the center of the intervention is the shared space. This large volume features double-height ceilings and contains a kitchen, a living room, and a reception area. These are laid out in a single open-plan, platformed space. To the right of the shared volume is the writ- er’s space. It is composed of two levels. The top one contains the bedroom; the bottom one features an office with an extensive library. Finally, to the left is the pilot’s space. It is composed of a bedroom and a private living room with a small study. The varying plane angles observed in the previous phase are carried over to the design of the house. First, The roofs of each space are at differing heights and angles. This was done to ensure each space received ample amounts of natural light in the early hours of the day. Second, while the orientation of the shared and writer’s volumes is similar, the pilot is at a different angle. This shields the space from direct and bright natural light which might disturb the pilot’s rest.

11


2018

FINAL HOUSE MODEL

IAD

12


2018

FINAL HOUSE MODEL

IAD

13


BMSP

2017

Biomedical Signal Processing

12 Weeks Individual 2017 University of Surrey

Biomedical signal processing (BMSP) is the extraction and analysis of raw biomedical signals produced by the underlying physiological mechanisms of living organisms. While at the University of Surrey, I studied electrical signals produced by the human brain (EEG) and cardiac muscles (ECG) as part of a course in BMSP. The goal was to determine how specific pathologies could be detected and further understood using biomedical signals. Complex mathematical concepts and models were used to manipulate raw sets of data extracted from healthy and pathological patients. MATLAB was the tool used throughout. As a whole, the course showcased the importance of visualization and presentation of complex data in synthesizing a correct analysis.

14


ECG - CARDIAC AUTONOMIC NEUROPATHY

2017

BMSP

Cardiac Autonomic Neuropathy (CAN) is a common complication experienced by Diabetes patients. It is the cause of cardiac dysfunction and multiple clinical symptoms, including resting tachycardia, exercise intolerance, postural hypotension, silent ischemia, cardiomyopathy, and perioperative instability. Two, twenty minutes long, Electrocardiograms (ECG) of a CAN positive and CAN negative patient were analyzed using Central Tendency Measure (CTM). The CTM is a concept in statistics used to measure the tendency of data to cluster around a middle value. Here, scatter plots of the first differences between data points were plotted. It was found that CAN+ data was contained within a smaller range than CAN- data. Furthermore, the CAN+ subject’s scatter plot featured an empty area. The importance of these observations is that they allow us to determine alternative ways of diagnosing pathologies. In this case, pre-emptive measures can be taken to mitigate the negative consequences that arise from the complications caused by CAN. These analysis efforts not only enable an anticipatory approach rather than a reactive one based on symptoms, they also identify key characteristics of pathologies, facilitating their diagnosis.

15


BMSP

IEEG - SEIZURES

2017

Seizure free recordings from epileptogenic zone

Seizure free recordings from hippocampal formation

Recordings of seizure activity

Epilepsy is a neurological disorder characterized by recurring brain seizures:

Spectrograms are used to display the fluctuations of power of the different

sudden, uncontrolled electrical disturbances in the brain, causing changes in

frequencies of a signal over time. The filtered data set was manipulated to

behavior, movement, or feelings.

produce spectrograms. The comparison of the spectrograms of iEEGs taken during seizure-free and seizure activity yielded the following conclusions:

A set of iEEG measurements, taken from different parts of the brain of epileptic subjects during seizure and seizure-free activity, was analyzed. Intracranial

During a seizure, the power of electrical signals increases throughout the fre-

Electroencephalograms (iEEG) are recorded by placing electrodes within the

quency spectrum. The variation in frequencies becomes rhythmic, character-

skull, directly onto exposed surfaces of the brain.

istic of the epileptogenic zone, even during seizure-free activity.

For this analysis, the set of raw data was filtered digitally to remove as much

More importantly, the power of frequencies between 10 and 20 Hz is signifi-

as possible of unwanted artifacts (noise).

cantly greater. The frequency bands located within that range are associated with motor control, which explains the uncontrolled movement of body parts during seizures.

16


2017

VARIOUS GRAPHS

BMSP

17


HEPHAESTUS HAND

2017/18

Hephaestus Hand

24 Weeks Group of 6 2017 - 2018 University of Surrey

During the third and final year of my undergraduate studies, I participated in a group design project which was part of the biomedical engineering curriculum at the University of Surrey. The project aimed to design a high-end, trans-radial prosthesis composed of a hand and a wrist, operated through bio-potentials from the musculoskeletal system.

The complexity of the product being created required coordinated and organized teamwork. My involvement centered on the development of the actuation mechanism, from the selection of the electromechanical components to the design of the different parts of the mechanism.

18


BENCHMARK ANALYSIS

2017/18

HEPHAESTUS HAND

Anthropomorphic Data of Human Hand

We started by researching the anatomy and prime movement patterns of the human hand. Our goal was to replicate as much of the natural capabilities of a hand and its fingers. Furthermore, we strived to create a product whose proportions closely matched those of a human hand. To do so, we gathered the corresponding anthropomorphic data and highlighted the dimensions to focus on (red in the figure/table above). These goals guided the decisions made throughout the length of the project. Our main constraints were related to technology and general costs. The price of high-end prosthetic hands available on the market at the time ranged between GBP 10,000 and GBP 30,000, with most being above the GBP 20,000 range. We set the production cost limit to GBP 15,000 as we believed this would allow us to design a product that would be made available to a higher number of patients. Human Hand (Top) & Finger (Bottom) Anatomy

19


CONCEPTUALISATION

2017/18

Concept Sketches

HEPHAESTUS HAND

Guiding Hand Concept

20


FINAL DESIGN - HEPHAESTUS HAND

2017/18

HEPHAESTUS HAND

The designed prosthesis comprises four fingers, a thumb, a palm, a wrist, a forearm socket, and its liner. It was named after the Greek god of fire and blacksmiths, Hephaestus. An electromechanical actuation mechanism, controlled through bio-potentials, allows for the fingers and thumb to move. The wrist can be manually locked into five different positions. The fingers and thumb move into a set of predetermined positions relative to one another, forming grip patterns. Grip patterns are used to Socket Liner

provide specific functionality such as grasping objects, pushing or pulling, pointing, and greeting. The Hephaestus hand is capable of producing a total of 10 patterns. Myo-electric signals from 5 muscles located in the residual limb are

Forearm

used to determine what grip pattern to produce. The contraction of one of these muscles produces a specific grip. As such, the ten grip patterns were divided into two sets of five. The user switches between sets

Wrist Palm

using buttons found on the anterior side of the forearm socket. Power and control of all electric units found inside the device are delivered by components placed inside the forearm. The control system uses various sensors placed in multiple locations within the device, which detect the position of the fingers/thumb, grip force being pro-

Pinky Ring Finger Middle Finger

duced, temperature, and bio-potentials. All of these connect to a miThumb Index Finger

cro-controller that commands based on the data it receives. A battery powers the whole system. Carbon Fibre Reinforced Polymers (CFRP) is used for all of the casing components (White). All load-bearing elements are made of Titanium (Green). A variety of soft tissues (Red) are also used for skin contact and dampening.

21


FINGER DESIGN

2017/18

Fused DIP Base

Proximal Phalanx Base

Rigid Bar Linkage Mechanism

HEAPHASTUS HAND

ElectroMechanical Actuation Unit

Design iterations were made for the middle finger and then scaled to the dimensions of the remaining fingers. Two sets of CFRP covers define the morphology of the designed fingers. The Medial and distal phalanges were fused into a single component as it was deemed unnecessary to have three moving joints. The lengths of the designed fingers are on average 9 centimeters greater than that of a human hand. This is due to the technology used to ensure all performance targets were met. A combination of electromechanical units and a rigid bar linkage mechanism generate the fingers' motion. Soft Fingertip Pad

Fused DIP Arch

Proximal Phalanx Arch

M1 Screw

These two elements make up the developed actuation mechanism. Force sensors inserted at the tip of the fingers monitor and control the generated grip force to ensure objects held are not damaged. Soft pads of butyl rubber protect these sensors from being damaged themselves.

22


ACTUATION MECHANISM

2017/18

Internal Distal Phalanx

Internal Medial Phalanx

Internal Proximal Phalanx

HEPHAESTUS HAND

DIP Joint

PIP Joint

Gearbox

Assembled Actuation Mechanism in a Extended (Relaxed) Position

Rigid Bar

Gearbox Rigid Bar

Gear Head

BLDC Motor

A rigid bar linkage mechanism produces the core movement of the fingers. It is composed of three segments connected by hinge joints. A rigid bar moved by a gearbox pulls the medial phalanx segment inwards. This motion forces a rigid bar attached to the proximal phalanx segment to pull the distal phalanx segment inwards as well, flexing the fingers. Extension is achieved by having the gearbox's rigid bar push the medial phalanx segment. The actuation mechanism was designed to produce a maximum nominal force of 20N at the tip of the fingers. A cubic volume of 70 mm x 16 mm x 16 mm within the palm was assigned to each finger's electromechanical actuation unit. Motors fitting within these dimensions were found to be unable to produce the required grip force. Thus, gear heads and gear boxes were used to amplify the output of the motors. Bevel gears located inside the gearbox translate the rotational motion, generated by the motors, by 90 degrees.

Assembled Actuation Mechanism in a Partially Flexed (Contracted) Position

23


THUMB

2017/18

Lateral Joint Unit

Lateral Gear

HEPHAESTUS HAND

Lateral Motor

The human thumb is capable of both flexion and extension, as well as lateral movement. Both were replicated with a smaller number of degrees of freedom. The mechanism responsible for the flexion Phalanx Block Unit

Electro Mechanical Actuation Unit

and extension of the thumb's phalanx block unit is identical to that of the one developed for the fingers. However, it is inserted onto a lateral joint unit. At the bottom of the unit is a gear slotted into a bar located inside the palm, on the palm's thumb block. This gear is put into motion by a separate motor, hence producing the thumb's lateral movement.

24


PALM

2017/18

HEPHAESTUS HAND

Palm Lid Wrist Block

Thumb Block

Finger Support

Posterior View of Assembled Palm

Palm Block

Anterior View of Assembled Palm

25


WRIST

2017/18

HEPHAESTUS HAND

Palm Connection Rigid Bar Pin Rotator Block Foam Support

Locking Pin Rigid Bar

Wrist Block Socket Connection

26


FOREARM

2017/18

Doning Hole

HEPHAESTUS HAND

Switch Buttons Slots

Anterior View of the Forearm Assembly Unit

M1 Screw Bio-Potential Sensor Cutouts

Compartment Lid Battery & Control Compartment

Posterior View of the Forearm Assembly Unit

27


FINITE ELEMENT ANALYSIS

2017/18

Boundary conditions (Left) Radial Deformation contour plot (Right) occuring at the arch of the modular segment upon the application of a torque equivalent to 10 Nm.

Total deformation (Left) and shear strain (Right) distribution upon the application of a torque equivalent to 7kg placed on an outstretched palm was applied to the rotating element.

HEPHAESTUS HAND

Boundary conditions (Left) and primary mode shape (Right) upon the application of a lateral load of 100N along the axis of the forearm.

Equivalent stress (Left) Total deformation (Right) distributions Upon the application of a 294.3N vertical force on the anterior surface of the palm casing.

28


GRIP PATTERNS

2017/18

Pointing Index

Hook

HEPHAESTUS HAND

Power

Hang Loose

29


THANK YOU FOR YOUR ATTENTION