Month: January 2017

Kinematic comparison of surgical tendon-driven manipulators and concentric tube manipulators

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Abstract

Robot manipulators are increasingly used in minimally invasive surgery (MIS). They are required to have small size, wide workspace, adequate dexterity and payload ability when operating in confined surgical cavity. Snake-like flexible manipulators are well suited to these applications. However, conventional fully actuated snake-like flexible manipulators are difficult to miniaturize and even after miniaturization the payload is very limited. The alternative is to use underactuated snake-like flexible manipulators. Three prevailing designs are tendon-driven continuum manipulators (TCM), tendon-driven serpentine manipulators (TSM) and concentric tube manipulators (CTM). In this paper, the three designs are compared at the mechanism level from the kinematics point of view. The workspace and distal end dexterity are compared for TCM, TSM and CTM with one, two and three sections, respectively. Other aspects of these designs are also discussed, including sweeping motion, scaling, force sensing, stiffness control, etc. From the results, the tendon-driven designs and concentric tube design complement each other in terms of their workspace, which is influenced by the number of sections as well as the length distribution among sections. The tendon-driven designs entail better distal end dexterity while generate larger sweeping motion in positions close to the shaft.

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BN2204 FUNDAMENTALS OF BIOMECHANICS

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BN2204ย FUNDAMENTALS OF BIOMECHANICS
2016/2017, Semester 2ย  Engineering (Biomedical Engineering)

Modular Credits: 4 Class Size: 95

Learning Outcomes

The module aims to introduce students to the applications of engineering statics and dynamics to perform simple force analysis of the musculoskeletal system; give an appreciation of kinematics and kinetics of human motions; apply the fundamentals of mechanics, i.e. stress and strain in biological systems, shear force, bending moment and torsion.

At the end of this course, students should be able to:

  1. Draw free body diagrams and identify unknown reaction forces and moments
  2. Solve statically determinate problems involving rigid bodies, pin-jointed structures
  3. Understand the concepts of engineering stress, strain and materials behaviour
  4. Determine the load distributions and corresponding stresses and strains in structures under tension, shear, compression, torsion and bending
  5. Design structures to prevent failure including buckling
  6. Describe the anatomical structures of the major joints and spine of a human body and relate to body movement and functions
  7. Analyze the kinematics & kinetics of human movement
  8. Explain the time dependent behavior of human movement

Prerequisites

PC1431 Physics IE

Teaching Modes

Module will consists of Lectures, Tutorials, Labs and Continual Assessment (CA) where:

โ€ขย ย  CA will comprise term papers/quizzes (20%) and lab assignments (30%).
โ€ขย ย ย  As such, total CA will constitute 50% of the total marks. The rest of 50% will come from the final examination.
ย ย 

Schedule

Lecture

Tutorial

Lab

Lecturer

Wk 1: 9 Jan
Wk 2: 16 Jan
Wk 3: 23 Jan
Wk 4: CNY
Wk 5: 6 Feb

Wk 1: –
Wk 2: 19 Jan
Wk 3: –
Wk 4: 2 Feb
Wk 5: 9 Feb

Wk 1: –
Wk 2: 20 Jan
Wk 3: 25 Jan
Wk 4: 1,3 Feb
Wk 5: 8,10 Feb

Prof. Lim Chwee Teck

Wk 6: 13,16 Feb

Wk 6:-

Wk 6:-

A/Prof. Toh Siew Lok

18 – 26 Feb RECESS WEEK

Wk 7: 27 Feb
Wk 8: 6 Mar

Wk 7: 2 Mar
Wk 8: 9 Mar

Wk 7:-
Wk 8:-

Wk 9: 13 Mar
wk 10: 20 Mar
Wk 11: 27 Mar
Wk 12: 3 Apr
Wk 13: 10 Apr

Wk 9: 16 Mar (Quiz)
wk 10: 23 Mar
Wk 11: 30 Mar
Wk 12: 6 Apr
Wk 13: 13 Apr

Wk 9:-15, 17 Mar
wk 10: 22,24 Mar
Wk 11: 29,31 Mar
Wk 12: 5, 7 Apr
Wk 13:-

Asst Prof. Ren Hongliang

Wk 17 Apr

Reading Week

Wk 15: 22 Apr onwards

Examination

Module

Lab Group

Lab Time

Exp 1

Exp 2

BN2204

U01

Wed 2 – 5

25-Jan

29-Mar

BN2204

U02

Wed 2 – 5

1-Feb

22-Mar

BN2204

U03

Wed 2 – 5

8-Feb

15-Mar

BN2204

U04

Wed 2 – 5

15-Feb

8-Mar

BN2204

U05

Friย  9 – 12

20-Jan

17-Mar

BN2204

U06

Friย  9 – 12

3-Feb

24-Mar

BN2204

U07

Friย  9 – 12

10-Feb

10-Mar

BN2204

U08

Friย  9 – 12

17-Feb

31-Mar

Syllabus

Prof Lim C.T.

  1. Introduction to Biomechanics
  2. Statics applied to Biomechanics
    1. Characteristics of Forces; Static Equilibrium of Rigid Bodies
  3. Introduction to Mechanics of Deformable Body
    1. Concept of Stress and Strain
    2. Basic mechanical loads
    3. Behaviour of elastic and viscoelastic materials

ย 
Prof Toh S.L.

  1. Indeterminate systems (Axial & Torsion)
  2. Combined stresses
  3. Failure Theories
  4. Fatigue & Endurance

ย 
Prof Ren H.L.

  1. Biomechanical analysis of human motion
  2. Body and joint movement
  3. Kinematics โ€“ Linear and Angular
  4. Kinetic โ€“ Linear and Angular
  5. Gait analysis
  6. Inverse dynamics and link-segment modelling

Preclusions

EG1109/EG1109M Statics and Mechanics of Materials
ย 

Workload

2-1-0.5-3-3.5

Workload Components : A-B-C-D-E
A: no. of lecture hours per week
B: no. of tutorial hours per week
C: no. of lab hours per week
D: no. of hours for projects, assignments, fieldwork etc per week
E: no. of hours for preparatory work by a student per week

Hybrid Tele-Manipulation System Using a Sensorized 3-D-Printed Soft Robotic Gripper and a Soft Fabric-Based Haptic Glove

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Abstract

This paper presents a hybrid tele-manipulation system, comprising of a sensorized 3D-printed soft robotic gripper and a soft fabric-based haptic glove, that aim at improving grasping manipulation and providing sensing feedback to the operators. The flexible 3D-printed soft robotic gripper broadens what a robotic gripper can do, especially for grasping tasks where delicate objects such as glassware are involved. It consists of four pneumatic finger actuators, casings with through hole for housing the actuators, and adjustable base. The grasping length and width can be configured easily to suit a variety of objects. The soft haptic glove is equipped with flex sensors and soft pneumatic haptic actuator, which enables the users to control the grasping, to determine whether the grasp is successful and to identify the grasped object shape. The fabric-based soft pneumatic haptic actuator can simulate haptic perception by producing force feedback to the users. Both the soft pneumatic finger actuator and haptic actuator involve simple fabrication technique, namely 3D-printed approach and fabric-based approach respectively, which reduce fabrication complexity as compared to the steps involved in traditional silicone-based approach. The sensorized soft robotic gripper is capable of picking up and holding a wide variety of objects in this study, ranging from lightweight delicate object weighing less than 50 g to objects weighing 1100 g. The soft haptic actuator can produce forces of up to 2.1 N, which is more than the minimum force of 1.5 N needed to stimulate haptic perception. The subjects are able to differentiate the two objects with significant shape differences in the pilot test. Compared to the existing soft grippers, this is the first soft sensorized 3D-printed gripper, coupled with a soft fabric-based haptic glove, that has the potential to improve the robotic grasping manipulation by introducing haptic feedback to the users.

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