PRE2019 3 Group13

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Group members

Student name Student ID Study E-mail
Yara Daamen 1337157 Pyschology & Technology y.f.daamen@student.tue.nl
Heather Hanegraaf 1330454 Biomedische Technologie h.e.h.hanegraaf@student.tue.nl
Mayke Scheffer 1234784 Electrical Engineering m.scheffer1@student.tue.nl
Wouter Haneveer 1300334 Computer Science w.haneveer@student.tue.nl
Gijs van Bakel 1239471 Applied Physics g.v.bakel@student.tue.nl

Problem Statement

Simple tasks like eating are not as obvious for everyone. For instance: people with a tremor, or who are suffering from Parkinson’s disease have trouble with something as simple as bringing a spoon to their mouth. Their meals take a lot longer and they often have to be assisted while eating. There are several products available on the market like self-stabilizing spoons and forks. The disadvantage of these products is that they are quite expensive and big. This means people are able to eat independent again, but they should always take their own cutlery with them.

Objectives

Cost efficient

To keep the safety of the user’s in mind, the device should cost less than €100, - since they most likely have to carry it with them often and an expensive device can increase the risk of getting robbed. A lower price also increases the accessibility for more people.

Comfortable in use

The device should be comfortable in use for the target group. It should have a shape that is comfortable for at least 90% of the users for the duration of a three-course meal. Using the device should not cause any pain or harm and users should have no negative feelings against using it. These criteria will be verified through user tests. The user should be fully comfortable to use the device within two weeks of getting used to it.

Recognize nature of movement

The device should recognize unwanted vibrations that are, for instance, caused by a tremor or Parkinson’s disease. The unwanted vibrations should be distinguished from wanted movement of the cutlery within one period of movement. The error in recognizing the nature of the movement should be less than 10%.

Act on unwanted movement

When an unwanted movement is recognized, this should be compensated by keeping the piece of cutlery stable. The stabilizing should not take more than two periods of the unwanted vibrations. The piece of cutlery should only be allowed to move in the direction of the wanted movements.

Modular

The device should be compatible with at least 90% of the cutlery that is used in restaurants. Therefore the part of the device that is connected to the cutlery must be adjustable in size and it should be able to attach and use the device within one minute. The device should be able to work for at least three hours without intermediate charging.

Approach, Planning, Milestones and Deliverables

Approach

The aim of this project is to help people with nerve diseases such as tremor to become more independent. We are going to do this by making special cutlery, which makes it possible to eat independently for this target group. We want to achieve this goal by delivering a prototype and model on how the cutlery can be implemented. The approach to reach those two goals contains multiple steps.

1. Research

Firstly, we will be going through research papers and other sources which describe the state of art of such cutlery and its respective components. This allows our group to get a grasp of the current technology of such a system and introduce us to the new developments in this field. This also helps to create a foundation for the project, which we can develop into. The state of art also gives valuable insight into possible solutions we can think and whether their implementation is feasible given the knowledge we possess and the limited time. The Research has to be done with the use of literature, survey(s), personal interview(s), recent reports from research institutes and the media and analyzing patents which are strongly connected to our project.

2. USE aspects

Furthermore, we will continue to analyze the problem from a USE – user, society, enterprise – perspective. An important source of this analysis is the state of art research, where the results of these cutlery systems in different stakeholders are discussed. The USE aspects will be of utmost importance for our project as every engineer should strive to develop new technologies for helping not only the users but also the society as a whole and to avoid the possible consequence of the system they develop. This analysis will finally lead to a list of requirements for our design.

3. Product shaping

Finally, we hope to develop a prototype in which the product will be conceptualized and programmed. In this process the RPC's are used to choose the program, hardware and the approach of the programming language itself.

4. Documentation

The wiki has to be updated and look like a report at the end of the project. To accomplish this someone will be assigned to check and edit the page every week. Besides the wiki, a presentation has to be made in anticipation of the last few weeks. Together with the prototype, the wiki page and the presentation are our final deliverables for the project.

Below the summary of the main steps in our approach of the project.

  • Doing research on our chosen project using SotA literature analysis
  • Analyzing the USE aspects and determining the requirements of our system
  • Choose the Hardware and Software for the prototype
  • Work on the prototype
  • Create a demo of the tracking functionality
  • Evaluate the prototype

Milestones

Here the major milestones can be found for every week. :

  • Week 1: The subject is chosen and also the Plan for the project has been made.
  • Week 2: It is clear who the users are, the research is finished and also the requirements are decided.
  • Week 3: Research into design prototype and costs + Enquete.
  • Week 4: Research into software prototype and a list of parts and estimation of costs is made + Enquete.
  • Week 5: Building prototype + information from enquete to improve the prototype.
  • Week 6: The prototype has been made.
  • Week 7: The tracker demo will be finished in order to be at the presentations.
  • Week 8: The wiki page is finished and updated with the results that were found from testing the prototype. Also, future developments are looked into and added to the wiki page.

Deliverables

Within this project there are four final deliverables.

  • This wiki page, which contains all of our research and findings
  • A presentation, which is a summary of what was done and what our most important results are
  • A prototype
  • A video of the tracker demo

Planning

Name Week #1 Week #2 Week #3 Week #4 Week #5 Week #6 Week #7 Week #8
Research RPC's and USE Analysis + start prototype research Hardware Design + Enquete Software Design + Enquete Prototype / Model implement Proof Reading Future Developments Conclusions
Heather Hanegraaf Write approach, milestones and deliverables Requirements Wiki Page check Wiki Page check
Brainstrom subject ideas Requirements justification Survey
Make the planning Adjust Planning
Yara Daamen Research 13 papers USE Analysis Wiki Page check Wiki Page check
Add the research papers to the wiki page Survey
Mayke Scheffer Write problem statement and objectives Research Prototype Wiki Page check Wiki Page check
Wouter Haneveer Research 5 papers Requirements Justification Wiki Page check Wiki Page check
Add the research papers to the wiki page Summary State of the art sources 7-25
Gijs van Bakel Write User part Research Prototype Wiki Page check Wiki Page check
Research 7 papers Summary state of the art sources 1-6
Group Work Brainstorm about the subject during meeting Meeting Planning + prepare feedback session Group meeting
Online meeting (Whatsapp) about subject

User Analysis

The primary users that this project is focused on are people with tremors, patients who suffer from Parkinson's disease in particular. According to volksgezondheid.info, an estimate of 52.200 people suffer from the condition in the Netherlands. The disease is more common the older a person gets, and is extremely rare in people under 50 years old.

What the users require is the following:

1. Autonomy

The user requires the device to be autonomous, so it must be able to reduce the effects of tremors without needing the patient to exert extra effort.

2. Independence

The user requires the device the be used independently, without the assistance of any other person.

3. Compatibility

The user must be able to use the device on any cutlery.

4. Comfortability

The user must be able to use the device for extended amounts of time without being uncomfortable.

Requirements

The requirements follow from the user analysis. This is because the users are going to use the product and therefore the device must meet their requirements. The requirements that are still unclear after the user analysis has been carried out are clarified with a survey. In this survey, questions are asked about the specifications to our target group. Under the heading "Survey" there is more to read about how this happened.

Requirement ID Requirement description
R1 The spoon must ensure that a person with a disability in the nervous system can eat independently
R2 The spoon must cancel out at least 50% of a sudden movement caused by a tremor
R3 The size of the cutlery must not be larger than a normal spoon
R4 The weight of the cutlery must not be larger than 50 gram (AMOUNT)
R5 The cost of the robot must not be higher than 100 euro
R6 The spoon must be able to withstand water or other liquid
R7 The robot must be able to withstand heat flux
R8 The device should have constructive elegance
R9 Energy consumption should be as low as possible
R10 The device must work for 1 hour without the need for replenishing batteries.
R11 The device must be safe to use, i.e. no risk of getting high Voltage
R12 === Komt nog uit de user analysis / survey ===
R13 === Komt nog uit de user analysis / survey ===
R14 === Komt nog uit de user analysis / survey ===
R15 === Komt nog uit de user analysis / survey ===
R16 === Komt nog uit de user analysis / survey ===
R17 === Komt nog uit de user analysis / survey ===
R18 === Komt nog uit de user analysis / survey ===

Requirements Justification

The most important requirement is of course that the spoon must help the user to eat independently. So the first requirement speaks for itself. It must also be measurable for the spoon to work, which is why it has been stated that the spoon must be able to remedy 50% of all movements. In this way it is testable whether the spoon is indeed functioning properly.

Furthermore, there are also requirements for the weight and size of the device. It must of course be handy to use, and therefore not larger or heavier than a regular spoon. The price of the spoon is also important, since comparable but very expensive products are already on the market. We want to develop a product that is affordable for everyone, so a requirement has been set for the price of the product.

Literature Study

Several papers have been collected on the topic of self-stabilizing wearables, which are shown at this end of this section, together with a short summary in one or two sentences. They are sorted into distinctive categories for clarity. The following section summarizes the most important findings of the collected literature for our project.


Active cancellation hardware is currently used in noise-cancelling headphones. [1] This method uses two DC motors connected with mechanical yokes that couple vertical and horizontal motion of the spoon. The sensor/controller system uses a tri-axial accelerometer embedded in the spoon base to sense the direction of tremor in the x and y directions and directs the spoon the move in the opposite direction. A bandpass filter is uses to filter out noise, and acceleration data as a function of time is resolved into the frequency domain using Fourier transformation. [2]


Vibration isolation and a dynamic vibration absorber can be used to reduce the hand tremor with a semi-active device, which can not only reduce hand tremor but also generate its needed electrical energy. A Schematic of this can be seen below. [3] In this system, two clamped guided piezoelectric beams (B1 and P1) are used to hold the spoon and a clamped piezoelectric beam (B2 and P2) is used as a dynamic vibration absorber.


A PID controller can be used to actively control the system. This type of controller continuously calculates an error value e(t) as the difference between a desired setpoint (SP) and a measure process variable (PV) and applies a correction based on proportional, integral, and derivative terms (denoted P, I and D respectively), hence the name (from Wikipedia) In the study “Design of a noninvasive and smart hand tremor attenuation system with active control: a simulation study” two motors are used that can rotate in perpendicular directions, which allow the mechanism tip to move horizontally and vertically. [4]


Another method uses Inertial measurement unit (IMU) sensors and actuators for stabilizing a cup while under severe hand vibration. It is like the Active force method in the sense that a microcontroller processes the feedback from the IMU, upon which it rotates the two motors in the opposite direction of hand movement in order to achieve proper stabilization. PI and PID controllers are also used for the self-stabilizing cup. [5]


Note on the frequency of tremors: Based on previous studies, it is concluded that the frequency of the hand tremor is different from the frequency of the voluntary movement. Accordingly, the frequency of the hand tremor in Parkinson’s disease is in range of 3–6 Hz and it is between 5 and 12 Hz in essential tremor disease Therefore, a low-pass filter, with a cut-off frequency of 3 Hz, can be used to distinguish the voluntary motion from tremor movement. [6]

Next to self-stabilizing wearables we also did research on ways to reduce tremors, here the most important findings to reduce tremors.

One could think about adding weight to the patient's wrist or use a heavier spoon, since then an equal amount of force would mean less movement since the mass is bigger [7], however contradictory to [8] , [9] states that no significant changes can been seen by adding weight.

Another thing that could be done to the spoon is to make the handle smaller. As [10] shows a smaller handle makes people with the Parkinson's disease move faster and smoother, possibly since they have more control over the spoon due to the shorter distance to is.

An exoskeleton can also be used to suppress tremors [11]. Here an exoskeleton uses an electromyogram (EMG) signal, which is a biosignal which affects the activation of muscles, to measure whether movement in voluntary or not, if the movement is voluntary the exoskeleton moves with the body else it will not move and suppress the movement. However, exoskeletons can be used in other parts of the arm as well, like seen in [15] much more complicated exoskeletons can be made, this one uses Active Force Control (AFC) based on piezoelectric actuators to reduce tremors in the wrist.

Tremors could also be reduced by measuring distance to something and keeping this distance the same with the help of motors [12] . However, for our project this is not relevant since we want our tool to be useable in dynamic environment and to pick up food, we need to go towards the food and this way would work against what we want.

With the use of accelerometers, actuators and position sensors, tremors could be seen and reduced by countering the force of the tremor with an equally big force into the opposite direction, according to [13]. However, this system is designed for cars and is therefore to big and expensive to use for a spoon. If a way smaller and cheaper version could be made it might be a good way to reduce tremors in a spoon, the problem is that it might be difficult to see whether a movement is from a tremor or a voluntary movement from the user itself.

By rotating an unbalanced mass, one could counter and thus reduce a tremor [14] . However, added on a spoon this would make the spoon heavy since we should add multiple masses to be albe to create a counter force in every direction, thus making it not usable for cutlery.

Using a coin type vibration motor and a micro controller, it is possible to create random vibration patters to distract the user from the bio-mechanical feedback loop with the hand and reduces the hand tremor and improving the ability to grip or hold an object [15] .

Lastly, we found that muscle co-contraction could be used to stabilize joints [16] . When a tremor is measured, the muscles are electronically contracted to stabilize the joint, this reduces the tremors since your muscles are contracted and thus unable to create a tremor.

Similar products

[1] Thilmany, J. (2013). Stable spoon. Mechanical Engineering; New York, 135(5).

Spoon that cancels human tremors. Same technique as in noise cancelling headphones: active cancelation software. Digital cameras also cancels motion. LiftWare tremor-cancelling spoon from company Lift Labs.

[2] Pathak, A., Redmond, J. A., Allen, M., & Chou, K. L. (2013). A noninvasive handheld assistive device to accommodate essential tremor: A pilot study. Movement Disorders, 29(6), 838–842. https://doi.org/10.1002/mds.25796

Research on how active cancellation of tremor (ACT) can stabilize motion of spoon. Results show that the device helps reduce tremor amplitude and severity. Same company Lift Labs.

[3] Abbasi, M., & Afsharfard, A. (2018). Modeling and experimental study of a hand tremor suppression system. Mechanism and Machine Theory, 126, 189–200. https://doi.org/10.1016/j.mechmachtheory.2018.04.009

Very useful for our project. Research on application of the system. By experiments they obtain and validate electromechanical equations.

[4] Abbasi, M., Afsharfard, A., Arasteh, R., & Safaie, J. (2018). Design of a noninvasive and smart hand tremor attenuation system with active control: a simulation study. Medical & Biological Engineering & Computing, 56(7), 1315–1324. https://doi.org/10.1007/s11517-017-1769-9

Same researchers. Simulated study on how the device will work.

[5] Vishnu, V., Prabaharan, P., Sujadevi, V.G., Meher, M.D.IMU sensor based self-stabilizing cup for elderly and parkinsonism (2017) 2017 International Conference on Advances in Computing, Communications and Informatics, ICACCI 2017, 2017-January, pp. 2264-2269.

A proposal for a wearable auto stabilizing cup holder that helps in routine performance tasks such as drinking water. The system uses IMU sensors and actuators for stabilizing the cup when under severe hand vibration.

[6] Turgeon, P., Laliberte, T., Routhier, F., Campeau-Lecours, A. Preliminary design of an active stabilization assistive eating device for people living with movement disorders(2019) IEEE International Conference on Rehabilitation Robotics, 2019-June, art. no. 8779388, pp. 217-223. DOI: 10.1109/ICORR.2019.8779388

A preliminary design for a stabilizing eating device. It includes mechanical design, damping arrangement, electronic design and control algorithms.

Solutions to reduce tremors

[7] McGruder, J., Cors, D., Tiernan, A. M., & Tomlin, G. (2003). Weighted Wrist Cuffs for Tremor Reduction During Eating in Adults With Static Brain Lesions. American Journal of Occupational Therapy, 57(5), 507–516. https://doi.org/10.5014/ajot.57.5.507

Research on the usage of weights on the forearm. Research shows that making the wrist heavier resulted in less tremors while self-feeding for some individuals.

[8] Meshack, R. P., & Norman, K. E. (2002). A randomized controlled trial of the effects of weights on amplitude and frequency of postural hand tremor in people with Parkinson’s disease. Clinical Rehabilitation, 16(5), 481–492. https://doi.org/10.1191/0269215502cr521oa

Again research on weighted utensils for patient suffering from Parkinson’s Disease. This time no support for significant effect on reduction of the tremor.

[9] Matsumoto, Y., Seki, M., Ando, T., Kobayashi, Y., Nakashima, Y., Iijima, H., … Fujie, M. G. (2013). Development of an Exoskeleton to Support Eating Movements in Patients with Essential Tremor. Journal of Robotics and Mechatronics, 25(6), 949–958. https://doi.org/10.20965/jrm.2013.p0949

Usage of exoskeleton to suppress tremors and support voluntary movement. The research shows that the exoskeleton works to a certain extent.

[10] Song, C., Gehlbach, P. L., & Kang, J. U. (2012). Active tremor cancellation by a “Smart” handheld vitreoretinal microsurgical tool using swept source optical coherence tomography. Optics Express, 20(21), 23414. https://doi.org/10.1364/oe.20.023414

In the medical world are tremors also an obstacle, especially for microsurgeons. The device helps steady the surgeon tool by cancelling the tremors. This could also be applied our subject.

[11] Ma, H.-I., Hwang, W.-J., Chen-Sea, M.-J., & Sheu, C.-F. (2008). Handle size as a task constraint in spoon-use movement in patients with                Parkinson’s disease. Clinical Rehabilitation, 22(6), 520–528. https://doi.org/10.1177/0269215507086181

Research on the effect of the size of a spoon handle on the amount of tremors that a Parkinson’s Disease patient is experiencing. The results show that a smaller to medium sized spoon handle caused a faster and smoother movement compared to a big handle.

[12] Hamdy, A. (1999). Active damping of vibrations in elevator cars. Journal of Structural Control, 6(1), 53–100. https://doi.org/10.1002/stc.4300060105

Usage of active damping system for cars. Doesn’t apply perfectly to the spoon but shows how a system can actively reduce the extremes.

[13] Chuanasa, J., & Songschon, S. (2014). Essential tremor suppression by a novel self-balancing device. Prosthetics and Orthotics International, 39(3), 219–225. https://doi.org/10.1177/0309364614525185

Self-balancing device that can be used for tremor suppression. Algorithm controls mass actuator.

[14] Rovini, E., & Merammani, C., & Cavallo, F. (2017) How wearable sensors can support parkinson’s disease diagnosis and treatment: A systematic view. Frontiers in Neuroscience, 11 (OCT), art. no. 555. DOI: 10.3389/fnins.2017.00555.

Review of 136 papers that shows a wide overview of wearable devices for the management of Parkinson’s disease. Objectives: This review focuses on wearable devices for PD applications and identifies five main fields: early diagnosis, tremor, body motion analysis, motor fluctuations (ON-OFF phases), and home and long-term monitoring.

[15] Hosseini, S.M., Al-Jumaily, A., Kalhori, H.Tremor suppression in wrist joint using active force control method(2017) 9th Australasian Congress on Applied Mechanics, ACAM 2017, 2017-November.

The paper proposes a new AFC (active force control) method for tremor attentuation, using a three-degree-of-freedom musculoskeletal model. Matlab is used to analyze the model. Conclusion: AFC-based system with a piezoelectric actuator and a PD controller is very effective is suppressing the human hand tremor.

[16] Vidya, V., Poornachandran, P., Sujadevi, V.G., Dharmana, M.M.Suppressing Parkinson's diseases induced involuntary movements using wearables(2018) Proceedings of 2017 IEEE International Conference on Technological Advancements in Power and Energy: Exploring Energy Solutions for an Intelligent Power Grid, TAP Energy 2017, pp. 1-4. DOI: 10.1109/TAPENERGY.2017.8397267

This paper proposes and implements a low-cost wearable assistive device for Parkinson’s disease patients. A coin vibrator motor a micro controller are used. The induced vibration on the wrist distracts the patient’s brain from the bio-mechanical feedback loop with the hand and reduces the tremor and improving the ability to grip or hold an object.

[17] Gallego, J.A., Rocon, E., Belda-Lois, J.M., Pons, J.L. A neuroprosthesis for tremor management through the control of muscle co-contraction (2013) Journal of NeuroEngineering and Rehabilitation, 10 (1), art. no. 36. DOI: 10.1186/1743-0003-10-36

This study uses a neuroprosthesis in order to reduce effects of tremors. The treatment relies on muscle co-contraction for tremor management. Results: The neuroprosthesis attained significant attenuation of tremor (p<0.001), and reduced its amplitude up to a 52.33±25.48%.


Reading tremors

[18] Lauk, M., Timmer, J., Lücking, C. H., Honerkamp, J., & Deuschl, G. (1999). A software for recording and analysis of human tremor. Computer Methods and Programs in Biomedicine, 60(1), 65–77. https://doi.org/10.1016/s0169-2607(99)00012-7

Research on monitoring the different types of tremors by analyzing the recording and applying mathematical methods.

[19] Marino, S., Cartella, E., Donato, N., Muscarà, N., Sorbera, C., Cimino, V., … Di Lorenzo, G. (2019). Quantitative assessment of Parkinsonian tremor by using biosensor device. Medicine, 98(51), e17897. https://doi.org/10.1097/md.0000000000017897

Home-made and low-cost device that can read tremors.

[20] Serrano, J.I., Lambrecht, S., del Castillo, M.D., Romero, J.P., Benito-León, J., Rocon, E.Identification of activities of daily living in tremorous patients using inertial sensors(2017) Expert Systems with Applications, 83, pp. 40-48. DOI: 10.1016/j.eswa.2017.04.032

Instead of measuring tremors, the paper instead focuses on contextualizing the symptoms of diseases like Parkinson’s. The study describes the development of a comprehensive methodology based on machine learning techniques to segment and detect activities of daily living in people with tremor using inertial sensors, which aims at facilitating detailed interpretation of tremor movements by neurologists.

[21] Mehmet Engin (2006). A recording and analysis system for human tremor. Measurement, 40(3), 288-293. https://doi.org/10.1016/j.measurement.2006.05.015

Tremor analysis based on frequency and amplitude to diagnose people’s condition.

[22] Gugliandolo G, Capra PP, Bramanti A, Di Lorenzo G, Campobello G, Donato N, Marino S (2019). A Movement-Tremors Recorder for Patients of Neurodegenerative Diseases. IEEE Transactions on Instrumentation and Measurement, 68(5), 1451-1457. https://doi.org/10.1109/TIM.2019.2900141

Tremor recorder for people affected by neurodegenerative diseases.

[23] Reem Musab, Azizan As’arry, Khairil Anas Md Rezali, Nawal Aswan Abdul Jalil, Raja Mohd Kamil Raja Ahmad, Mohd Zarhamdy Md Zain (2019). Tremor Quantification and its Measurements Using Shimmer. Journal of Physics: Conference Series, 1262. https://dx.doi.org/10.1088/1742-6596/1262/1/012024

Different sensors to measure tremors and comparison between them.Different sensors to measure tremors and comparison between them.

Possible users

[24] Deuschl, G., Petersen, I., Lorenz, D., & Christensen, K. (2015). Tremor in the elderly: Essential and aging-related tremor. Movement Disorders : Official Journal of the Movement Disorder Society, 30(10), 1327-34. doi:10.1002/mds.26265

Tremor research on elderly, seen is that people get tremors as they get older.

[25] Balestrino, R., & Schapira, A. (2020). Parkinson disease. European Journal of Neurology, 27(1), 27-42. doi:10.1111/ene.14108

General research on Parkinson's disease.


References

  1. Thilmany, J. (2013). Stable spoon. Mechanical Engineering; New York, 135(5)
  2. Pathak, A., Redmond, J. A., Allen, M., & Chou, K. L. (2013). A noninvasive handheld assistive device to accommodate essential tremor: A pilot study. Movement Disorders, 29(6), 838–842. https://doi.org/10.1002/mds.25796
  3. Abbasi, M., & Afsharfard, A. (2018). Modeling and experimental study of a hand tremor suppression system. Mechanism and Machine Theory, 126, 189–200. https://doi.org/10.1016/j.mechmachtheory.2018.04.009
  4. Abbasi, M., Afsharfard, A., Arasteh, R., & Safaie, J. (2018). Design of a noninvasive and smart hand tremor attenuation system with active control: a simulation study. Medical & Biological Engineering & Computing, 56(7), 1315–1324. https://doi.org/10.1007/s11517-017-1769-9
  5. Vishnu, V., Prabaharan, P., Sujadevi, V.G., Meher, M.D.IMU sensor based self-stabilizing cup for elderly and parkinsonism (2017) 2017 International Conference on Advances in Computing, Communications and Informatics, ICACCI 2017, 2017-January, pp. 2264-2269.
  6. Bhidayasiri R (2005) Differential diagnosis of common tremor syndromes. Postgrad Med J 81(962):756–762. https://doi.org/10.1136/ pgmj.2005.032979
  7. McGruder, J., Cors, D., Tiernan, A. M., & Tomlin, G. (2003). Weighted Wrist Cuffs for Tremor Reduction During Eating in Adults With Static Brain Lesions. American Journal of Occupational Therapy, 57(5), 507–516. https://doi.org/10.5014/ajot.57.5.507
  8. McGruder, J., Cors, D., Tiernan, A. M., & Tomlin, G. (2003). Weighted Wrist Cuffs for Tremor Reduction During Eating in Adults With Static Brain Lesions. American Journal of Occupational Therapy, 57(5), 507–516. https://doi.org/10.5014/ajot.57.5.507
  9. Meshack, R. P., & Norman, K. E. (2002). A randomized controlled trial of the effects of weights on amplitude and frequency of postural hand tremor in people with Parkinson’s disease. Clinical Rehabilitation, 16(5), 481–492. https://doi.org/10.1191/0269215502cr521oa
  10. Ma, H.-I., Hwang, W.-J., Chen-Sea, M.-J., & Sheu, C.-F. (2008). Handle size as a task constraint in spoon-use movement in patients with Parkinson’s disease. Clinical Rehabilitation, 22(6), 520–528. https://doi.org/10.1177/0269215507086181
  11. Meshack, R. P., & Norman, K. E. (2002). A randomized controlled trial of the effects of weights on amplitude and frequency of postural hand tremor in people with Parkinson’s disease. Clinical Rehabilitation, 16(5), 481–492. https://doi.org/10.1191/0269215502cr521oa
  12. Song, C., Gehlbach, P. L., & Kang, J. U. (2012). Active tremor cancellation by a “Smart” handheld vitreoretinal microsurgical tool using swept source optical coherence tomography. Optics Express, 20(21), 23414. https://doi.org/10.1364/oe.20.023414
  13. Hamdy, A. (1999). Active damping of vibrations in elevator cars. Journal of Structural Control, 6(1), 53–100. https://doi.org/10.1002/stc.4300060105
  14. Chuanasa, J., & Songschon, S. (2014). Essential tremor suppression by a novel self-balancing device. Prosthetics and Orthotics International, 39(3), 219–225. https://doi.org/10.1177/0309364614525185
  15. Vidya, V., Poornachandran, P., Sujadevi, V.G., Dharmana, M.M.Suppressing Parkinson's diseases induced involuntary movements using wearables(2018) Proceedings of 2017 IEEE International Conference on Technological Advancements in Power and Energy: Exploring Energy Solutions for an Intelligent Power Grid, TAP Energy 2017, pp. 1-4. DOI: 10.1109/TAPENERGY.2017.8397267
  16. Gallego, J.A., Rocon, E., Belda-Lois, J.M., Pons, J.L. A neuroprosthesis for tremor management through the control of muscle co-contraction (2013) Journal of NeuroEngineering and Rehabilitation, 10 (1), art. no. 36. DOI: 10.1186/1743-0003-10-36