How should I use the Cricket wearable sensor?

Safety Information

For safe usage, please follow the operational guidelines (temperature, humidity, elevation) specified in the instruction manual included with your Cricket sensor.

Additionally, please be aware that the Cricket sensor contains a rechargeable Lithium Ion battery. The same care should be taken with the Cricket sensor as you would with any product with an internal Lithium Ion battery:

1) Do not leave it running in the sun. It can overheat.

2) It is normal for the sensors to feel a little bit warm after being charged.

3) If the sensors feel hot during charging, immediately disconnect it. Do not use it. Call Somaxis customer support (number is listed in the About section of the Chirp app).

4) If you notice any physical bulging of the sensor’s back surface, immediately disconnect it. Do not use it. Call Somaxis customer support.

5) Follow “common-sense” practice as you would when dealing with any product that contains a Lithium Ion battery pack inside it.

Can I use the Cricket for relaxation training?

Yes, absolutely.

Relaxation training can benefit greatly from the use of biofeedback (visual cues, audible tones, and haptics / vibration), implemented in a particular manner (often called a training protocol) in order to help someone become relaxed and/or learn how to control the stress response through active training.

Typically, the personal tension monitor is a supplement to relaxation training. After practicing a relaxation training protocol, you can use the Pyramid muscle tension monitor to supplement your learning process by giving you audible feedback and/or gathering muscle tension data continuously in the background as you go about your day at work, on the road, at home, and anywhere else that you want to train with it.

Can I use Cricket for biofeedback?

The short answer to this question is “Yes”.

The longer answer is that “biofeedback” is a vague term that is commonly used in different ways:

1. Biofeedback is any time that your biometric data is made visible to you. When you take your temperature with a thermometer you are getting biofeedback. When you weigh yourself on your scale you are getting biofeedback.

2. Another definition of biofeedback holds that biofeedback is any time that biometric information is fed back to the user with the intention of changing a behavior. However, that definition is actually just one use-case. Behavior change is often, but not always, the goal.

3. Biofeedback, the way that people use the term commonly today, is usually in reference to real-time visualizations of heart rate, heart rate variability, respiration, muscle tension, skin conductance, and mental focus. Again, the intention is often (but not always) to use this data to change a behavior. The Apple Watch has biofeedback capabilities.

4. “Biofeedback Training” is sometimes used to refer to types of physical and/or psychological training that use biofeedback as at least one component of the training protocol. This is, in itself, a very broad category that includes sports, fitness, rehabilitation, ergonomics, and physical therapy (to name a few).

5. “Biofeedback Therapy” is a mixed-use term. It can refer to the use of biofeedback as a tool for performing medical diagnosis or treatment of a medical condition. The Cricket does not have FDA certification, and is not intended for use as a medical device. However, “Biofeedback Therapy” can also refer to Progressive Relaxation Therapy and other therapies that are not intended to cure a medical condition. Sometimes Biofeedback Therapy is also used as a method of reducing stress, generally.

6.”Neurofeedback” is a form of biofeedback training or biofeedback therapy that specifically relates to EEG. Common real-time metrics are for visualizations of mental focus and/or mental relaxation. Cricket does support EEG recordings, but does not presently support real-time presentation of the EEG data to the user. However, we do plan to release a Meditation module that incorporates neurofeedback.

Biofeedback is a function subcategory of Wearable Sensors, which is a subcategory of Sensors. Sensors have logically separate functionality for tracking and biofeedback. A tracker is saving your data, but might not give you access to the information in real-time (no direct “feedback” to the user). For example, many wearables today are primarily trackers with extremely limited biofeedback capability.

Can I use Cricket as a research tool for gathering sEMG, EKG, EEG, or IMU (6-axis) data?

Yes, absolutely. The data quality is very good, and supports use as a research tool.

Most researchers prefer to export the data and then import it into their own analysis software. For this, you should use Chirp to record the data, synch with Halosphere, log into Halosphere on a computer and then export to CSV.

Can I use the Cricket as a personal tension monitor?

Yes. Check out “Chirp Guide 05”, above, for a quick look at how to get live muscle tension feedback with The Pyramid.

The Pyramid (which can be accessed in Chirp via Quickstart 1, #5) offers a basic personal tension monitor, and has independent settings for configuring audio feedback which will continue to work if you turn the iPad screen off. With The Pyramid, data is not saved. The Cricket will work passively in the background – even if the iPad’s screen is off – giving you biofeedback that relates to your muscle tension levels as you engage in day-to-day activities.

Visual feedback and audio feedback are independently configurable, and haptic feedback will be released as a feature in the next update.

The Pyramid is appropriate for use as a progressive relaxation tool.

What kind of research is done with EXG sensors?

Somaxis Science: Publications & Research involving EXG (EMG, EKG, EEG)

At Somaxis, we are continually building our research capabilities to enhance the Cricket’s functionality and stay at the forefront of the rapidly evolving field of biosensor technology research. Please contact clin@somaxis.com for questions and comments about Somaxis research.

Stress Management

* Kalia M. Assessing the economic impact of stress–the modern day hidden epidemic. Metabolism. 2002 Jun;51(6 Suppl 1):49-53.
http://www.ncbi.nlm.nih.gov/pubmed/12040542/
SUMMARY: The World Health Organization (WHO) Global Burden of Disease Survey estimates that mental disease, including stress-related disorders, will be the second leading cause of disabilities by the year 2020. This article examines the economic effects of all forms of stress-work-related stress, home stress, and post-traumatic stress disorder (PTSD).

* Wu W, Gil Y, Lee J. Combination of wearable multi-biosensor platform and resonance frequency training for stress management of the unemployed population. Sensors (Basel). 2012 Sep 27;12(10):13225-48.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3545565/
SUMMARY: This article describes a wearable biofeedback sensor system tested in an unemployed population over three weeks of resonance frequency training (RFT) biofeedback strategy for stress management. Results found that after 3 weeks of using this sensor system there was improved autonomic nervous system regulating function as indicated by increased heart rate variability and decreased sympathetic activities.

Stress in the Workplace

* Mörl F, Bradl I. Lumbar posture and muscular activity while sitting during office work. J Electromyogr Kinesiol. 2013 Apr;23(2):362-8.
http://www.ncbi.nlm.nih.gov/pubmed/23122693
Summary: Office workers examined by sEMG for their lumbar spine muscle activation during sitting, standing, and walking found very low levels of lumbar muscle activation while sitting, which may contribute to low back pain related to increased load on the spinal discs and ligaments in sedentary workers.

* Johnston V, Jull G, Darnell R, Jimmieson NL, Souvlis T. Alterations in cervical muscle activity in functional and stressful tasks in female office workers with neck pain. Eur J Appl Physiol. 2008 Jun;103(3):253-64.
http://www.ncbi.nlm.nih.gov/pubmed/18293008
SUMMARY: In workers with neck pain, sEMG recordings demonstrated that this group had more difficulty switching off their upper trapezius muscle activation and had more typing errors compared to controls and workers without neck pain.

* Johnston V, Jull G, Souvlis T, Jimmieson NL. Neck movement and muscle activity characteristics in female office workers with neck pain. Spine (Phila Pa 1976). 2008 Mar 1;33(5):555-63.
http://www.ncbi.nlm.nih.gov/pubmed/18317202
SUMMARY: In female office workers with neck pain, their upper trapezius, cervical spine extensor, and anterior scalene neck muscles were unable to relax even after completion of a task. Findings suggest that a motor reeducation program may be helpful.

* Goudy N, McLean L. Using myoelectric signal parameters to distinguish between computer workers with and without trapezius myalgia. Eur J Appl Physiol. 2006 May;97(2):196-209.
http://www.ncbi.nlm.nih.gov/pubmed/16804735
SUMMARY: Myoelectric signals recorded from the trapezius muscles in computer workers with and without complaints of upper shoulder muscle pain found differences in trapezius muscle activity between the groups related to motor control and active muscle tension, but not to fatigue.

* Westgaard RH, Vasseljen O, Holte KA. Trapezius muscle activity as a risk indicator for shoulder and neck pain in female service workers with low biomechanical exposure. Ergonomics. 2001 Feb 20;44(3):339-53.
http://www.ncbi.nlm.nih.gov/pubmed/11219764
SUMMARY: In female shopping center and healthcare service workers, EMG activity level in the trapezius muscles was low (static activity level < 1% EMGmax), despite the high prevalence of shoulder and neck pain for both groups, raising the consideration of factors such as stress, independent of degree of muscle activation as a predictor of shoulder and neck pain. * Thorn S, Søgaard K, Kallenberg LA, Sandsjö L, Sjøgaard G, Hermens HJ, Kadefors R, Forsman M. Trapezius muscle rest time during standardised computer work--a comparison of female computer users with and without self-reported neck/shoulder complaints. J Electromyogr Kinesiol. 2007 Aug;17(4):420-7. http://www.ncbi.nlm.nih.gov/pubmed/16829137 SUMMARY: In a study of female computer users with sEMG recordings from the upper trapezius muscles during a typing and editing task, those with neck/shoulder complaints showed lower trapezius muscle relative rest time (RRT) and higher muscle amplitude levels compared to controls during tasks indicating an increased motor response to a psychological stressor in those with neck/shoulder pain. * Szeto GP, Straker LM, O'Sullivan PB. Neck-shoulder muscle activity in general and task-specific resting postures of symptomatic computer users with chronic neck pain. Man Ther. 2009 Jun;14(3):338-45. http://www.ncbi.nlm.nih.gov/pubmed/18606558 SUMMARY: Comparison of muscle activity when office workers with chronic neck pain versus asymptomatic controls performed two resting postures: 1) hands on the lap versus 2) hands on a keyboard. Those with chronic neck pain had higher muscle activity in the right upper trapezius when resting their hands on a keyboard compared to the controls, suggesting altered muscle activation patterns triggered by anticipatory task demand in these individuals with neck pain. * Blangsted AK, Søgaard K, Christensen H, Sjøgaard G. The effect of physical and psychosocial loads on the trapezius muscle activity during computer keying tasks and rest periods. Eur J Appl Physiol. 2004 Mar;91(2-3):253-8. http://www.ncbi.nlm.nih.gov/pubmed/14569401 SUMMARY: During a computer keying task, psychosocial loads added to the same physical work did not increase trapezius muscle activity measured by sEMG and increasing duration of short (30 second) and long (4 minute) breaks did not result in muscle relaxation.

Sports Performance

* Intille SS, Lester J, Sallis JF, Duncan G. New horizons in sensor development. Med Sci Sports Exerc. 2012 Jan;44(1 Suppl 1):S24-31.
http://www.ncbi.nlm.nih.gov/pubmed/22157771
SUMMARY: Review discusses the advancements in sensor technology that will enhance capabilities in tracking physical activity, posture, and physiological state and applications for sports science research and consumer use.

* Srinivasan J, Balasubramanian V. Low back pain and muscle fatigue due to road cycling—An sEMG study. J Bodywork Movement Therapies. (2007)11:260–266.
http://www.sciencedirect.com/science/article/pii/S1360859206000751
SUMMARY: In an evaluation of muscle fatigue in cyclists with and without low back pain (LBP) using sEMG before and after cycling, the LBP group showed significantly higher fatigue in the right trapezius and erector spinae back muscles when compared to those without LBP.

The Science Behind the Cricket

Heart Rate Variability Monitoring

* Zucker TL, Samuelson KW, Muench F, Greenberg MA, Gevirtz RN. The effects of respiratory sinus arrhythmia biofeedback on heart rate variabilityand posttraumatic stress disorder symptoms: a pilot study. Appl Psychophysiol Biofeedback. 2009 Jun;34(2):135-43.
http://link.springer.com/article/10.1007%2Fs10484-009-9085-2
SUMMARY: This pilot study provides preliminary evidence for the efficacy of respiratory sinus arrhythmia biofeedback training in improving physiological and psychological health for individuals with PTSD by increasing heart rate variability while reducing pathological symptoms.

* Wahbeh H, Oken BS. Peak high-frequency HRV and peak alpha frequency higher in PTSD. Appl Psychophysiol Biofeedback. 2013 Mar;38(1):57-69.
http://link.springer.com/article/10.1007%2Fs10484-012-9208-z
SUMMARY: In veterans with and without PTSD, peak high frequency heart rate variability (HRV) lower in the PTSD group when adjusted for respiratory rate. Peak high frequency HRV and peak alpha frequency are sensitive to PTSD status and might be helpful biofeedback parameters in this population.

* Sutarto AP, Wahab MNA, ZinNM. Heart Rate Variability (HRV) biofeedback: A new training approach for operator’s performance enhancement. Journal Industrial Engineering Management. 2010. 3(1):176-198
http://www.jiem.org/index.php/jiem/article/view/135/0
SUMMARY: Heart rate variability biofeedback training can help improve some cognitive functions in both simulated and real industrial operators.

Electroencephalography (EEG) in Neurobiofeedback

* Sokhadze TM, Cannon RL, Trudeau DL. EEG biofeedback as a treatment for substance use disorders: review, rating of efficacy, and recommendations for further research. Appl Psychophysiol Biofeedback. 2008 Mar;33(1):1-28.
http://www.ncbi.nlm.nih.gov/pubmed/18214670
SUMMARY: EEG biofeedback such as alpha theta training (for alcoholism) or beta training (stimulant and mixed substance abuse) has been used in substance use disorders in conjunction with other therapies such as residential treatment programs and it might be useful in enhancing certain outcomes of therapy. Further research is needed.

* Gruzelier J, Egner T, Vernon D. Validating the efficacy of neurofeedback for optimising performance. Prog Brain Res. 2006;159:421-31.
http://www.ncbi.nlm.nih.gov/pubmed/17071246
SUMMARY: The scientific basis to neurobiofeedback using SMR, beta, and alpha-theta EEG protocols for improving attention, memory, mood, and music and dance performance needs further validation studies.

* Gruzelier J. A theory of alpha/theta neurofeedback, creative performance enhancement, long distance functional connectivity and psychological integration. Cogn Process. 2009 Feb;10 Suppl 1:S101-9.
http://www.ncbi.nlm.nih.gov/pubmed/19082646
SUMMARY: Alpha-theta EEG-neurobiofeedback training may be beneficial for optimizing creative performance enhancement in dance and music.

Respiratory Sensor for Biofeedback
* Liu GZ, Huang BY, Wang L. A wearable respiratory biofeedback system based on generalized body sensor network. Telemed J E Health. 2011 Jun;17(5):348-57.
http://online.liebertpub.com/doi/full/10.1089/tmj.2010.0182
SUMMARY: This study describes a wearable respiratory biofeedback system based on a generalized body sensor network platform. Pilot studies on wearable training patterns and resultant heart rate variability suggest that paced respirations can help decrease sympathetic arousal and increase parasympathetic activity.

Cricket Specifications

What are the product specifications?

Cricket
by Somaxis

1. Overview

Cricket is a wearable device with multiple on-board sensors. It is capable of recording data appropriate for use in the measurement of:

a) sEMG (muscles)
b) EKG (heart)
c) EEG (brain)
d) IMU (movement / position): 6-axis
i. Delta X
ii. Delta Y
iii. Delta Z
iv. Pitch
v. Yaw
vi. Roll

2. Requirements

a) iPad with BLE support:
iPad, 3rd generation
iPad, 4th generation
iPad mini
iPad mini 2
iPad mini 3
iPad Air
iPad Air 2
b) Computer
c) Internet connection (for some functionality)

3. Simultaneity & Channel Count

a) Cricket can measure one (1) channel of EXG data and six (6) channels of IMU data (XYZPRY) at the same time.
b) Cricket may be moved around the body for serial EXG measurements of different areas at different times.
c) Each iPad supports four (4) Crickets connected at the same time.
d) Multiple iPads (no limit) may record data at the same time and then the user may combine data sets via the cloud portal (“Halosphere”). In this manner, 16+ channel counts can be easily achieved.

4. IMU, EXG, Patches

a) The user may use IMU sensor (aka “accelerometer” / “gyroscope”) without Patches
b) EXG requires the use of Patches

5. Sensor Quality (live streaming)

a) EXG sample rate: 1000 s/s
b) EXG sample depth: 16-bit
c) IMU sample rate: 30 s/s
d) IMU sample depth: 16-bit

6. Sensor Quality (theoretical)

Data quality is purposefully decreased in order to facilitate live streaming through Bluetooth. Nonetheless, the sensors on-board are physically capable of much more:
a) EXG sample rate: 8000 s/s
b) EXG sample depth: 24-bit
c) IMU sample rate: 1000 s/s
d) IMU sample depth: 16-bit

Custom quality settings will result in data being stored on a 12.5 Mb internal memory chip; therefore high quality samples can only be taken of short time-frames. Recording time is determined by desired quality setting, compression (or lack thereof), etc.

For information about unlocking custom quality settings, specialized applications can be developed by Somaxis for this purpose (by request). Please contact questions@somaxis.com

7. Power

a) Charge cycle time: 3 hours
b) Use time: 11 hours (live-streaming data at 1000 s/s EXG + 30 s/s IMU)
c) Standby time: 48 hours
d) Charge cycle performance limit: 1000 cycles
e) Do not charge from your computer’s USB port. Use the USB-to-power plug that comes with your iPad.

8. Patches

a) Patches last for up to 24 hours for a single use (no re-placement) if there is minimum sweating
b) Patches last for up to 4 hours for a single use (no re-placement) if there is sweating
c) Patches may not work with very oily or hairy skin types without “skin prep” – see Accessories in Shop
d) Always test patches indoors on your skin before going to an outdoor setting

9. Appropriate Use

a) Please see the separate FAQ question about “How should I use the Cricket wearable sensor”?

How many Crickets do I need? What’s the maximum number supported?

In addition to 6-axis IMU data, each Cricket can measure one (1) channel of EXG data. The question is: for any given application, how many different locations on the body need to be monitored?

For several applications, one Cricket is sufficient:

1. For instance, the personal tension monitor supports the use of one Cricket. Two is preferred so that muscle tension can be monitored on both sides, but that is not required.

2. For ergonomic evaluations, one Cricket is possible though the evaluation will take longer to complete in that case (12 minutes longer per client) as different functional groups are evaluated one at a time instead of simultaneously.

3. EEG (brain) recordings (FP1 and FP2 placements) are accomplished through one Cricket.

4. EKG (heart) recording is accomplished through one Cricket.

5. When posture support is released, one Cricket will be sufficient.

However, for other types of applications, more than one Cricket is required:

1. If you wish to be able to observe symmetry (between left and right sides of the body measured at the same time), then at least two (2) Crickets are required.

2. For simultaneous measurements of more than one “functional group” of muscles at the same time (i.e. quadriceps and hamstrings simultaneously) then 2 – 4 Crickets are recommended.

3. For profiling complex activities (such as yoga, exercise, or athletic performance), usually 2 – 4 Crickets are recommended.

4. If you wish to do workstation evaluations in the minimum amount of time possible per client, 4 Crickets are recommended – it saves you 12 minutes per evaluation (compared with 1 Cricket).

The maximum number of sensor supported depends on the number of iPads. Each iPad supports 4 Crickets, presently. There are plans to increase this. The maximum theoretical number is 10 per iPad, though most common applications do not require high channel count.

Note that you can have multiple iPads connected with Halosphere (data portal on web), in use simultaneously during a session. If your goal is to export data in CSV format, recorded at the same time with high channel counts (for export to Matlab, R, etc) then you can accomplish this by using multiple iPads. Halosphere has a feature (in beta) for merging data sets that were recorded at the same time.

What kinds of regulatory compliance is the Cricket subject to?

FCC Licensing:

Licensing

Cricket is not certified for use as a lifesaving medical device. It should not be used to diagnose or treat medical conditions. It should not be used in place of medical advice. If you have any health concerns, speak with your primary care physician.

What do I need to know about batteries / power?

Cricket uses an internal lithium ion battery that is rechargeable via the USB port on the device.

For regulatory and safety reasons, the device does not function when plugged into a power source (by USB).

You should not charge your device using a computer’s USB port. Use a power outlet on the wall, or plug into an extension strip using a power-to-USB adapter (such as the one that was included with your iPad / that you may use when you charge your iPad).

PowerToUsbApple

It takes 3 hours to fully charge your Cricket. iPads actually take a bit longer (5 – 7 hours) to fully charge, so you should also pay attention to your iPad’s battery life when planning your Cricket use.

The power level is reported to the iPhone app when the device is NOT charging (and when it is in active use). This is reported as a % Battery remaining.

A Cricket sensor lasts 11 hours when transmitting data in real-time via Bluetooth at 1000 s/s 16-bit EXG + 30 s/s & 16-bit IMU (x,y,z,p,r,y) simultaneously.

A Cricket lasts 48 hours in Standby Mode (aka “off”). Tip: fully charge the Cricket (and your iPad!) the night before on days when you plan to use it the next day.

Can I charge my Cricket sensor with my computer’s USB port?

At this time, no. Currently you must charge using a wall adapter such as the one that was provided with your iPad, iPad mini, etc (USB female to wall power).

You may use powered USB hubs to charge several Crickets at once, but not unpowered USB hubs.

Data

What kind of data can the Cricket collect?

TL;DR “Heart, muscle, brain, movement”

1. Cricket has an EXG sensor.

E “X” G is short for Electro-something-ography; it’s a kind of meta-acronym that includes:

  • E M G = Electromyography (Muscle Sensor)
  • E E G = Electroencephalography (Brain Sensor)
  • E K G = Electrocardiography (Heart Sensor)
  • The current version of Chirp iPad software can record raw EXG (all three, above). EMG and EKG are available in real-time. Presently, EEG is not available for real-time feedback though we plan to support it in the future. Raw EEG data can still be recorded and exported.

    Using the Patch, the main placement that is practical for EEG recordings is FP1 and FP2, though an Adapter Module is available by request that allows for use with cables with snap electrode connections. This allows for custom placements for all three EXG modalities. Additionally, all EXG modalities use an “internal reference”. No need for a third lead / contact as in older generation systems. The two Patch ends (or the two cables, if the Adapter Module is being used) correspond with the positive and negative inputs of the instrumentation amplifier.

    Each Cricket can measure one (1) EXG stream at a time. For multiple simultaneous EXG data streams (multiple “channels”), multiple Crickets are used. For instance, to measure two muscles at the same time, two Crickets are needed. To measure the heart, the brain, and a muscle at the same time, three Crickets are needed. It should be understood that generally when we say “muscle”, we mean “skeletal muscle”.

    2. Cricket has an IMU sensor.

    IMU is an acronym that stands for Inertial Measurement Unit. It includes a gyroscope (measures rotational movement) and an accelerometer (measures linear displacement, and the direction of gravity). The IMU has 6 axes of data: Delta X, Delta Y, Delta Z, Pitch, Roll, and Yaw.

    The current version of Chirp iPad software can record all 6 axes of raw IMU data. There is no real-time interface for posture or movement data. For research purposes, users collect a stationary calibration sequence followed by an activity sequence. When recording data during a Session or Test in Chirp, EXG and IMU data will be saved together. Data can be exported to .csv via Halosphere (web portal), and can be imported into the researcher’s preferred program such as Matlab, Python, R, etc.

    By default, both EXG and IMU are saved together and are accessible via the .csv file exported through Halosphere.

    Patches are not required for gathering IMU data. Crickets may be used with textile accessories for this purpose (ask us about it), or affixed with paper tape.

    3. Raw data vs metrics

    Researchers develop metrics for use with each EXG type (“modality”):

  • EMG data can be used to measure muscle tension.
  • EKG data can be used for heart rate, heart rate variability, and respiration.
  • EEG data can be used to measure focus / concentration, mental relaxation, and stages of sleep.
  • IMU data can be used to measure posture, movement, limb position, and steps.

    …and these are just a few examples. Researchers are regularly developing new and improved algorithms and metrics for use of EXGIMU data in different contexts.

  • What kind of research is done with EXG sensors?

    Somaxis Science: Publications & Research involving EXG (EMG, EKG, EEG)

    At Somaxis, we are continually building our research capabilities to enhance the Cricket’s functionality and stay at the forefront of the rapidly evolving field of biosensor technology research. Please contact clin@somaxis.com for questions and comments about Somaxis research.

    Stress Management

    * Kalia M. Assessing the economic impact of stress–the modern day hidden epidemic. Metabolism. 2002 Jun;51(6 Suppl 1):49-53.
    http://www.ncbi.nlm.nih.gov/pubmed/12040542/
    SUMMARY: The World Health Organization (WHO) Global Burden of Disease Survey estimates that mental disease, including stress-related disorders, will be the second leading cause of disabilities by the year 2020. This article examines the economic effects of all forms of stress-work-related stress, home stress, and post-traumatic stress disorder (PTSD).

    * Wu W, Gil Y, Lee J. Combination of wearable multi-biosensor platform and resonance frequency training for stress management of the unemployed population. Sensors (Basel). 2012 Sep 27;12(10):13225-48.
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3545565/
    SUMMARY: This article describes a wearable biofeedback sensor system tested in an unemployed population over three weeks of resonance frequency training (RFT) biofeedback strategy for stress management. Results found that after 3 weeks of using this sensor system there was improved autonomic nervous system regulating function as indicated by increased heart rate variability and decreased sympathetic activities.

    Stress in the Workplace

    * Mörl F, Bradl I. Lumbar posture and muscular activity while sitting during office work. J Electromyogr Kinesiol. 2013 Apr;23(2):362-8.
    http://www.ncbi.nlm.nih.gov/pubmed/23122693
    Summary: Office workers examined by sEMG for their lumbar spine muscle activation during sitting, standing, and walking found very low levels of lumbar muscle activation while sitting, which may contribute to low back pain related to increased load on the spinal discs and ligaments in sedentary workers.

    * Johnston V, Jull G, Darnell R, Jimmieson NL, Souvlis T. Alterations in cervical muscle activity in functional and stressful tasks in female office workers with neck pain. Eur J Appl Physiol. 2008 Jun;103(3):253-64.
    http://www.ncbi.nlm.nih.gov/pubmed/18293008
    SUMMARY: In workers with neck pain, sEMG recordings demonstrated that this group had more difficulty switching off their upper trapezius muscle activation and had more typing errors compared to controls and workers without neck pain.

    * Johnston V, Jull G, Souvlis T, Jimmieson NL. Neck movement and muscle activity characteristics in female office workers with neck pain. Spine (Phila Pa 1976). 2008 Mar 1;33(5):555-63.
    http://www.ncbi.nlm.nih.gov/pubmed/18317202
    SUMMARY: In female office workers with neck pain, their upper trapezius, cervical spine extensor, and anterior scalene neck muscles were unable to relax even after completion of a task. Findings suggest that a motor reeducation program may be helpful.

    * Goudy N, McLean L. Using myoelectric signal parameters to distinguish between computer workers with and without trapezius myalgia. Eur J Appl Physiol. 2006 May;97(2):196-209.
    http://www.ncbi.nlm.nih.gov/pubmed/16804735
    SUMMARY: Myoelectric signals recorded from the trapezius muscles in computer workers with and without complaints of upper shoulder muscle pain found differences in trapezius muscle activity between the groups related to motor control and active muscle tension, but not to fatigue.

    * Westgaard RH, Vasseljen O, Holte KA. Trapezius muscle activity as a risk indicator for shoulder and neck pain in female service workers with low biomechanical exposure. Ergonomics. 2001 Feb 20;44(3):339-53.
    http://www.ncbi.nlm.nih.gov/pubmed/11219764
    SUMMARY: In female shopping center and healthcare service workers, EMG activity level in the trapezius muscles was low (static activity level < 1% EMGmax), despite the high prevalence of shoulder and neck pain for both groups, raising the consideration of factors such as stress, independent of degree of muscle activation as a predictor of shoulder and neck pain. * Thorn S, Søgaard K, Kallenberg LA, Sandsjö L, Sjøgaard G, Hermens HJ, Kadefors R, Forsman M. Trapezius muscle rest time during standardised computer work--a comparison of female computer users with and without self-reported neck/shoulder complaints. J Electromyogr Kinesiol. 2007 Aug;17(4):420-7. http://www.ncbi.nlm.nih.gov/pubmed/16829137 SUMMARY: In a study of female computer users with sEMG recordings from the upper trapezius muscles during a typing and editing task, those with neck/shoulder complaints showed lower trapezius muscle relative rest time (RRT) and higher muscle amplitude levels compared to controls during tasks indicating an increased motor response to a psychological stressor in those with neck/shoulder pain. * Szeto GP, Straker LM, O'Sullivan PB. Neck-shoulder muscle activity in general and task-specific resting postures of symptomatic computer users with chronic neck pain. Man Ther. 2009 Jun;14(3):338-45. http://www.ncbi.nlm.nih.gov/pubmed/18606558 SUMMARY: Comparison of muscle activity when office workers with chronic neck pain versus asymptomatic controls performed two resting postures: 1) hands on the lap versus 2) hands on a keyboard. Those with chronic neck pain had higher muscle activity in the right upper trapezius when resting their hands on a keyboard compared to the controls, suggesting altered muscle activation patterns triggered by anticipatory task demand in these individuals with neck pain. * Blangsted AK, Søgaard K, Christensen H, Sjøgaard G. The effect of physical and psychosocial loads on the trapezius muscle activity during computer keying tasks and rest periods. Eur J Appl Physiol. 2004 Mar;91(2-3):253-8. http://www.ncbi.nlm.nih.gov/pubmed/14569401 SUMMARY: During a computer keying task, psychosocial loads added to the same physical work did not increase trapezius muscle activity measured by sEMG and increasing duration of short (30 second) and long (4 minute) breaks did not result in muscle relaxation.

    Sports Performance

    * Intille SS, Lester J, Sallis JF, Duncan G. New horizons in sensor development. Med Sci Sports Exerc. 2012 Jan;44(1 Suppl 1):S24-31.
    http://www.ncbi.nlm.nih.gov/pubmed/22157771
    SUMMARY: Review discusses the advancements in sensor technology that will enhance capabilities in tracking physical activity, posture, and physiological state and applications for sports science research and consumer use.

    * Srinivasan J, Balasubramanian V. Low back pain and muscle fatigue due to road cycling—An sEMG study. J Bodywork Movement Therapies. (2007)11:260–266.
    http://www.sciencedirect.com/science/article/pii/S1360859206000751
    SUMMARY: In an evaluation of muscle fatigue in cyclists with and without low back pain (LBP) using sEMG before and after cycling, the LBP group showed significantly higher fatigue in the right trapezius and erector spinae back muscles when compared to those without LBP.

    The Science Behind the Cricket

    Heart Rate Variability Monitoring

    * Zucker TL, Samuelson KW, Muench F, Greenberg MA, Gevirtz RN. The effects of respiratory sinus arrhythmia biofeedback on heart rate variabilityand posttraumatic stress disorder symptoms: a pilot study. Appl Psychophysiol Biofeedback. 2009 Jun;34(2):135-43.
    http://link.springer.com/article/10.1007%2Fs10484-009-9085-2
    SUMMARY: This pilot study provides preliminary evidence for the efficacy of respiratory sinus arrhythmia biofeedback training in improving physiological and psychological health for individuals with PTSD by increasing heart rate variability while reducing pathological symptoms.

    * Wahbeh H, Oken BS. Peak high-frequency HRV and peak alpha frequency higher in PTSD. Appl Psychophysiol Biofeedback. 2013 Mar;38(1):57-69.
    http://link.springer.com/article/10.1007%2Fs10484-012-9208-z
    SUMMARY: In veterans with and without PTSD, peak high frequency heart rate variability (HRV) lower in the PTSD group when adjusted for respiratory rate. Peak high frequency HRV and peak alpha frequency are sensitive to PTSD status and might be helpful biofeedback parameters in this population.

    * Sutarto AP, Wahab MNA, ZinNM. Heart Rate Variability (HRV) biofeedback: A new training approach for operator’s performance enhancement. Journal Industrial Engineering Management. 2010. 3(1):176-198
    http://www.jiem.org/index.php/jiem/article/view/135/0
    SUMMARY: Heart rate variability biofeedback training can help improve some cognitive functions in both simulated and real industrial operators.

    Electroencephalography (EEG) in Neurobiofeedback

    * Sokhadze TM, Cannon RL, Trudeau DL. EEG biofeedback as a treatment for substance use disorders: review, rating of efficacy, and recommendations for further research. Appl Psychophysiol Biofeedback. 2008 Mar;33(1):1-28.
    http://www.ncbi.nlm.nih.gov/pubmed/18214670
    SUMMARY: EEG biofeedback such as alpha theta training (for alcoholism) or beta training (stimulant and mixed substance abuse) has been used in substance use disorders in conjunction with other therapies such as residential treatment programs and it might be useful in enhancing certain outcomes of therapy. Further research is needed.

    * Gruzelier J, Egner T, Vernon D. Validating the efficacy of neurofeedback for optimising performance. Prog Brain Res. 2006;159:421-31.
    http://www.ncbi.nlm.nih.gov/pubmed/17071246
    SUMMARY: The scientific basis to neurobiofeedback using SMR, beta, and alpha-theta EEG protocols for improving attention, memory, mood, and music and dance performance needs further validation studies.

    * Gruzelier J. A theory of alpha/theta neurofeedback, creative performance enhancement, long distance functional connectivity and psychological integration. Cogn Process. 2009 Feb;10 Suppl 1:S101-9.
    http://www.ncbi.nlm.nih.gov/pubmed/19082646
    SUMMARY: Alpha-theta EEG-neurobiofeedback training may be beneficial for optimizing creative performance enhancement in dance and music.

    Respiratory Sensor for Biofeedback
    * Liu GZ, Huang BY, Wang L. A wearable respiratory biofeedback system based on generalized body sensor network. Telemed J E Health. 2011 Jun;17(5):348-57.
    http://online.liebertpub.com/doi/full/10.1089/tmj.2010.0182
    SUMMARY: This study describes a wearable respiratory biofeedback system based on a generalized body sensor network platform. Pilot studies on wearable training patterns and resultant heart rate variability suggest that paced respirations can help decrease sympathetic arousal and increase parasympathetic activity.

    What is your privacy policy? What is your license agreement?

    Is the data quality good?

    It is very good, appropriate for both high-end research and industrial use.

    Cricket can be used in different ways. When simultaneously streaming real-time EXG data and 6-axis IMU data:

  • EXG data is sampled 1000 times per second, suitable for frequency measurements up to 500 Hz. It is measured with 16-bit ADC resolution.
  • IMU data is 30 samples per second, and also has 16-bit ADC resolution. It includes 6 simultaneous data streams corresponding to: Delta X, Delta Y, Delta Z, Pitch, Yaw, and Roll. Colloquially speaking, this has both an accelerometer and a gyro.
  • Custom applications can be developed if the need arises. Higher sample rates are possible for EXG if IMU data is not required, and vice-versa. Generally, the highest sample rate possible is 2000 s/s for real-time EXG alone, and up to 8000 s/s for EXG recordings, using internal memory for short clips that synch after. 24-bit ADC resolution is also configurable if required. Contact us for details.
  • Power

    What do I need to know about batteries / power?

    Cricket uses an internal lithium ion battery that is rechargeable via the USB port on the device.

    For regulatory and safety reasons, the device does not function when plugged into a power source (by USB).

    You should not charge your device using a computer’s USB port. Use a power outlet on the wall, or plug into an extension strip using a power-to-USB adapter (such as the one that was included with your iPad / that you may use when you charge your iPad).

    PowerToUsbApple

    It takes 3 hours to fully charge your Cricket. iPads actually take a bit longer (5 – 7 hours) to fully charge, so you should also pay attention to your iPad’s battery life when planning your Cricket use.

    The power level is reported to the iPhone app when the device is NOT charging (and when it is in active use). This is reported as a % Battery remaining.

    A Cricket sensor lasts 11 hours when transmitting data in real-time via Bluetooth at 1000 s/s 16-bit EXG + 30 s/s & 16-bit IMU (x,y,z,p,r,y) simultaneously.

    A Cricket lasts 48 hours in Standby Mode (aka “off”). Tip: fully charge the Cricket (and your iPad!) the night before on days when you plan to use it the next day.

    Can I charge my Cricket sensor with my computer’s USB port?

    At this time, no. Currently you must charge using a wall adapter such as the one that was provided with your iPad, iPad mini, etc (USB female to wall power).

    You may use powered USB hubs to charge several Crickets at once, but not unpowered USB hubs.

    Patch Specifications

    How long do Patches last? How do Somaxis Patches compare to conventional electrodes?

    A single Patch enables you to acquire one channel of EXG data from one site on the body, one time.

    Each Cricket Patch represents the equivalent of three conventional electrodes (one “channel” of data). Conventional electrodes typically run on the order of $44.96 for 150, or about $0.30 each. One channel of data using three conventional electrodes costs USD $0.90 . Somaxis Patches cost $71.25 for 100; one channel of data using a Somaxis Patch costs USD $0.71. Discount pricing available for larger volumes of Patches.

    Patches are single-use. For each new placement, we recommend the use of a fresh Patch – even if it’s on a new location on the body of the same person. Don’t remove it and re-stick it somewhere else; change the Patch between locations. We also recommend not sharing Patches between clients.

    In terms of the length of time that a single Patch can be used, that depends on several things like skin type, oiliness, length of time since the last time cleaning the measurement area with soap, use of creams and lotions, sweat, and type of activity. Here are some rough estimates:

    ADL (Activities of Daily Life):
    Caveats: No Sweating, Low to medium-low hair in measurement area, no use of creams or lotions in measurement area
    Longevity: 24 hours (continual use)

    Running:
    Caveats: Average skin type, low hair, placement on the torso or legs)
    Longevity: 5 hours (Marathon use ok, should be changed after)

    In the Shower: NO. The material touching the skin is a hypoallergenic “hydrogel” material which has high water content. This makes it extremely comfortable to wear, and gentle on the skin. However, it also absorbs water and should not be worn in wet environments or it will eventually lose its adhesion.
    Under Water: NO.
    In the Rain: Light rain is ok if the Cricket is being worn underneath clothing.

    What are the placements for ergonomic evaluations?

    Somaxis Cricket Wearable Muscle Sensor sEMG EMG Placements FAQ

    For 1 Channel Ergonomic Evaluations, we recommend placing one sensor on the Right Upper Trapezius muscle group, as pictured above. Note this is actually a “functional group” placement, not a single muscle that is being monitored. Specifically, this placement monitors the Cervical Paraspinal muscles and the Upper Trapezius muscle. This monitors both head “craning” / spinal posture, as well as Muscle Loading / Tension in the Upper Trapezius group.

    For 2 Channel Ergonomic Evaluations, we recommend placing a sensor as in the “1 Channel” placement, and mirroring it on the left side of the body.

    For 4 Channel Ergonomic Evaluations, we recommend placing two sensors on the Right Upper Trapezius and Left Upper Trapezius muscles as in “1” and “2” above. Additionally, place 2 more sensors on the Lumbar Paraspinal group as pictured above, centered about 2” lateral to the spine.

    For all placements, make an effort to place the sensor pads on the “belly” of the muscle. Placements are not very location-sensitive for “functional group” measurements such as these, however the more consistent your placements are, the more consistent your measurements will be. We encourage you to use Chirp to take photographs of your sensor placements during EACH Ergonomic Evaluation. These will be automatically included in each Report so you can always review them later.

    Do we have to put Cricket sensors in those specific locations?

    For Ergonomic Evaluations specifically, it is recommended – yes. This is because our database references these locations and doing so will enable you to compare individual data to group data in a meaningful way.

    However, you can use Crickets to monitor any muscle group on the body! They are best suited to larger muscle groups, however we have adapter modules available that allow for smaller / customized placements as well. You can monitor any location on the body.

    Somaxis Cricket Wearable Muscle Sensor sEMG EMG Placement FAQ

    Why would I want to use other / non-standard placement locations?

    Research, sports science, biofeedback. Typically, you already know if you have specific requirements to monitor a specific muscle group that is not shown in the typical 1 – 4 Channel placements shown above. Feel free to contact us if you would like to chat about your particular placement requirements: questions@somaxis.com

    Regulatory

    What kinds of regulatory compliance is the Cricket subject to?

    FCC Licensing:

    Licensing

    Cricket is not certified for use as a lifesaving medical device. It should not be used to diagnose or treat medical conditions. It should not be used in place of medical advice. If you have any health concerns, speak with your primary care physician.

    Somaxis

    What have you been up to recently?

    By February 2013, we had developed a wearable electrophysiology sensor. The product was called MyoLink. We launched an Indiegogo campaign called “The MyoLink Emerges” and set a maximum of 100 sensors. We knew it would be wise to start small and learn from a controlled campaign. We sold out in 72 hours. Our goal was now to deliver 100 units in about 6 months.

    During the design review, we decided to start a fresh design process. To honor this, we rebranded as “Cricket” with the accompanying iPad app being called “Chirp”.

    By August 2013, we were shipping Crickets. The interfaces for the sensors were Chirp and the Chirp SDK (…which some backers, such as The Tech Museum of Innovation, used to great effect!)

    Over the next year or so in 2014 – 2015, we participated in the development and launch of the BodyMetrics exhibit at The Tech Museum, again scaling up our production efforts to support several hundred units in active circulation. During this time we aggregated an enormous contextual database of electrophysiology data – possibly the largest database of its kind.

    In 2015 – 2016, we did some angel fundraising in order to scale up from small-scale production to large-scale production. We created Chaoku, a joint-venture company based out of Suzhou, China in order to manufacture and distribute Somaxis products into Asian territories. By mid-2016, Cricket received FCC clearance and became available for purchase.

    Check out our Press Page

    What happened to the MyoLink?

    Short version: The MyoLink became the Cricket.

    For the longer version, check out the FAQ Question about “What have you been up to recently?”

    Support, Returns

    Support? Warranty? Care – Repair, Replacement? Returns?

    Policies for Crickets follow standard policies implemented by electronics manufacturers in the smart-device (smart-phone) space:

    1. Crickets are guaranteed operational for 30 days after the date of purchase. Crickets may be exchanged without penalty during this period if the reason for the return is a defect in manufacturing.

    2. Crickets are guaranteed operational for 1000 product cycles.

    3. Cricket Care Plan may be purchased for coverage against damage over a period of 2 years.

    4. Cricket Care Plan may be purchased retroactively any time in the first 30 days.

    5. Patches are guaranteed fresh until the expiration date listed on the individual packages.

    6. Patch sales are final. No returns accepted.

    Cricket Care Plan details:

    6. 2 years, 4 repairs, and 2 replacements due to damage

    7. Cricket Care Plan covers Crickets against accidental damage for a period of two (2) years from date of purchase. Cricket Care costs $44 per Cricket, and each time a damage incident is reported, the user pays a $15 deductible plus shipping. Cricket Care Plan does not cover against loss.

    Do you need tech support? Have any other questions?
    Contact us: questions@somaxis.com

    Chirp Guide 01: Intro, Quickstart

    Chirp Guide 01
    (5 minutes)

    Intro, Quickstart, Graph, Pyramid
    2016.07.18
    Chirp Guide 02: Data, Reports, Exporting, Sharing

    Chirp Guide 02
    (6 minutes)

    Data, Reports, Exporting, Sharing
    2016.07.18
    Chirp Guide 03: Design a Training Session, Record a Training Session

    Chirp Guide 03
    (4.5 minutes)

    Design and record Training Sessions
    2016.07.19
    Chirp Guide 04: Design Testing Session, Record Testing Session

    Chirp Guide 04
    (2.5 minutes)

    Design and record Testing Sessions
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    Chirp Guide 05: The Pyramid personal tension monitor

    Chirp Guide 05
    (5 minutes)

    The Pyramid tension monitor and trainer
    2016.07.20