SHANNEN KOH YING XUAN

Elaboration / record of the activities done:

The project aims to understand Parkinson’s Disease, how it is being treated, technological devices used and research done to improve data collected on Parkinson’s Disease. The value of such a project is to understand as well as assist these patients in further researching on these already existing systems that may be more accessible to general patients in financial terms. The resources put into this project are research online and readings given by the professor

At the point I joined the project, the status of the project was just reading articles given to us to have basic foundation of Parkinson's disease and to write up a literature review on what we have read. The task that I engaged in was to achieve in finding any possible ways to predict freezing of gait or to make the devices to detect gait of patients more available. And the way it could be done was to research other scholars articles to understand the current progress of predicting freezing of gait. Afterwards, trying to understand how it works, causes of freezing of gait, why it is important to predict it, how the device works etc.

The steps to completing the project are to read up on Parkinson's disease then divide the work within the group to understand gait movement, the device to track gait and how it works, machine learning and telehealth specifically going deeper to learn how it might be possible to predict freezing of gait in the future, how the current sensors work. And whether these sensors can be improved or how they track gait and send to a database to analyse the data. The rationale for such a process is based on these topics it can be linked together as they all need to be accounted for in the production for these devices as week as for further research and improvement of them. The benefits of such a process is that everyone gets to focus on a specific topic and after sharing as individual presentations we all can gather more information faster and more in depth.

The work I have done was to read 6 articles from the 31 articles given, gather the important points and input into the literature review. The outcome was that after gathering information and summarising them our group could very easily understand what all 31 articles are talking about through reading the literature review as well as anyone reason it. Also, we created a individual presentation on different points of which the outcome was that it allowed me to practice individual speaking skills and focus on in depth analysis. At the end we had a final presentation and had to come together and put it into a group presentation and the learning outcome was how the presentation had to be changed such that it was a group presentation so changes had to be made not individually but as a group to match with each other. The learning objectives were to research on the topic of Parkinson's disease and freezing of gait and they were achieved via the given articles and further research on the internet.

Gait Movement

Intro to human gait

Human Gait is the movement of the limbs that allows a person to walk forwards through the propulsion of shifting centre of gravity in the human body. It is that of which the body alternates in the movement in the waist and legs that allows a human to walk but with minimal energy used.

Gait Cycle

A gait cycle is the period of the movement of the feet when a foot touches the ground and when the same foot touches the ground again as a person walks or the walking patterns of a particular patient. Each stride has 2 phases:

1. Stance phase: Foot in contact with the ground
2. Heel Contact: Heel Strike, when the person first touches the ground with their heel
3. Foot Flat: It is the loading response of which the forefoot touches the ground thus the entire foot in flat touching the ground.

( at this moment, the other foot is in the position of opposite toe off, which is whereby the other foot is lifted from the ground but toe facing the ground)

(c) Mid Stance: opposite foot is lifted in the air but main foot is still on the ground

flat.

(d) Heel Off: Terminal Stance whereby the opposite is swung forward.

(e) Toe Off: The main foot about to lift from the ground, toe touching the ground

1. Swing Phase: Foot in the air, not in contact with the ground
2. Acceleration: Initial swing when the main foot is behind the opposite foot and lifted up
3. Mid Swing: the main foot overtakes the opposite foot which is in stance, specifically terminal stance
4. Deceleration: terminal swing of which the main foot moves forwards before its about to land on the ground with a heel strike

Gait Analysis takes into account variables which affect the gait cycle or are signs of abnormalities of a patient’s gait cycle. These variables are mainly time and distance and are usually analysed when a patient does the 10MWT or is wearing a wearable PD logger usually worn on the foot.

Distance Variables:

1. Step Length: distance between heel strikes of both feet
2. Stride Length: distance between the heel strikes of the same foot
3. Stride Width: The horizontal distance between 2 feet when walking
4. Foot Angle: Angle of foot placement

Time Variables:

1. Step Time: amount of time spent during every step, heel strike time between both feet
2. Stride Time: amount of time to complete one stride/ gait cycle
3. Stance Time: amount of time during the stance phase of a foot in one gait cycle
4. Single Limb Time: amount of time passing when one foot is supporting in the gait cycle
5. Double Limb Time: amount of time a person spends with both feet on the ground
6. Cadence: number of steps per unit time
7. Speed: distance covered by the body in unit time

Detecting FOG

• A long time that a PD patient stays in the same location will be the assumption that the patient is experiencing a FOG episode.
• When the sensor detects the forward movement changing but the PD patient not lifting their legs (shuffling)
• Freezing Index (FI) exceeds threshold, FOG occurs

Using frequency analysis for therapists to observe conditions of PD patients

Gait Abnormalities

Hemiplegic, Diplegic, Neuropathic, Choreiform, Ataxic, Sensory

Many gait abnormalities but specifically focusing on Parkinsonian Gait

Rigidity( stiff limbs) and Bradykinesia (slowness of movement)

Walks with slow little steps (marche a petits pas) → reduced stride time(shuffling), reduced mid-stride time, increased cadence, reduced step length and stride length, reduced speed or irregular acceleration (involuntary inclination to take accelerating steps, festination)

Cause: deficiency of dopamine in the basal ganglia* circuit leading to motor deficits (gait is one of the most affected motor characteristics of PD)

However, Parkinsonian Gait is not FOG. FOG is when a patient is unable to walk, and feet are stuck on the ground, while the upper body can still move even with intention to move forwards. Disorder of locomotion and Postural Stability

Variables affecting FOG

• Walking: compared to sitting or standing, walking increases the possibility of getting FOG
• Anxiety: Usually freezing patients experience higher anxiety levels than non-freezers.
• Tired: usually happen when patients are tired

FOG Prediction

The importance of predicting FOG is that because FOG impairs gait initiation and walking it thus will increase fall risk. While there are programs which can help patients recover gait after freezing, predicting FOG enables preemptive preparation and may prevent FOG. Also providing instructions during a FOG episode may result in cognitive overload causing an external cadence addition which may aggravate the FOG.

e.g. Identification of patterns (pre-FOG) based on motion data, according to specific patients

FOG prediction performance is highly patient dependent. 56% in FOG class of patients exhibiting enough gait degradation before FOG for accurate prediction.

Support Vector Machines, K-Nearest Neighbors, and Multi-Layer Perceptron experiment identified 97.4% of FOG events, 66.7% predicted → algorithm’s potential for accurate prediction of gait events

Limitations: most predictions are only around 1 second before the actual FOG

Observations: Those patients that will step slower before FOG easier to predict it could be a start

References

3 content knowledge / skills learnt:

• I learnt about the gait cycle and how it can be used to analyse the severity of Parkinson's disease patients as the symptoms of PD are rigidity and bradykinesia of which most commonly affects patients. There is a stance phase and stride phase mainly, which is to analyse the time and distance the patient's feet is on the ground and in the air.
• I learnt that treatment for Parkinson's disease is only to improve the conditions but it cannot be cured. Most common forms of medication is Levodopa or therapy to improve movement of patients. They also have a PD logger to track and analyse their movements and individual unique symptoms, in case they experience freezing of gait.
• Freezing of gait is the most dangerous symptom and can happen at any time thus hard to predict and it mainly causes a patient to start shuffling due to the feeling of being unable to lift their feet off the ground making them prone to falls and injuring themselves.

2 interesting aspects of your learning:

• While it was something new and harder to understand, it was genuinely rewarding to learn this topic of Parkinson's disease in depth, with resources from professionally researched articles.
• I think it was interesting to have the experience with doing a university researched project and having the guidance of a professor, letting me to have the chance to broaden my mind and have earlier experience of university.

1 takeaway for life :

One takeaway I have is that I got to choose something that I enjoy, which is about biology is the aspect of diseases, something I might never experience since I did not choose biology as one of my subjects so I really appreciate this opportunity.