Posts Tagged ‘GSR’

On Tuesday night at the Bord Gáis Energy Theatre here in Dublin we were equal parts proud, excited and honoured to be shortlisted in two categories at this year’s Allianz Business to Arts Awards.

Shimmer was nominated for a project we undertook with The LAB gallery as part of the Innovation Dublin festival. The project resulted in an art exhibition and surrounding series of talks on the theme of the Quantified Self.

In the spirit of the exhibition I decided to quantify myself during the course of the awards which provided some really interesting data.

I wore a single Shimmer sensor that monitored my movement, heart rate and GSR giving me a picture of my emotional engagement during the course of the evening. The Shimmer was streaming to my phone during the awards so I could see how I was doing in realtime, with the Android application also logging the data to file so that we could analyse offline after the event.

As readers of our blog or Facebook page will already know it’s been good year for the Shimmer trophy cabinet. That said we don’t take anything for granted and I think the impact (pleasant surprise!) of winning the award is evident for all to see on the post event analysis of my physiological data on the graph below.

The highlights are a major jump in heart rate when our award win was announced – my rate almost doubled to around 150 BPM immediately after the announcement and during time on stage – then returned to more normal resting state when I got back to my seat. You can also see a shift earlier in the graph at the point where we stopped mingling and took our seats at the start of the ceremony.

The psychological response graph which is based on GSR (changes in skin conductance – a measurement that underpins lie detector tests amongst other things) and indicates emotional engagement. The general rise (referred to as the tonic response in relation to GSR data) across the course of the night shows the gradual rise in tension and emotional engagement during a very enjoyable awards ceremony. The spike in physiological response (referred to as the phasic response in relation to GSR data) represents the heightened emotional engagement when the award was announced and while on stage.

Thanks again to all of our collaborators and the team at Business to Arts for a great evening.

The TRIL centre has recently published an article outline their work in developing an Alertness Training Programme. The programme is aimed at improving the attention and alertness of older people, which is seen to have a significant effect on how well they function at home and in their communities, and ultimately on their ability to live independently.

The device which was designed specifically with the end user in mind utilises a Shimmer GSR (Galvanic Skin Response) sensor to indicate and record levels of alertness by the user. The Shimmer GSR is integrated into a cushion like design which makes the device appear less medical or technical and therefore more approachable to non-technically inclined older adults.

Operation

Two leads protrude from the device, and Velcro loops with embedded sensors are worn on the fingers. When the device is switched on, it takes a baseline GSR reading.  The user presses the grey button before self-alerting, and the on-screen graph spikes upward to indicate a higher level of alertness, as measured by galvanic skin response.  The GSR data is recorded to a micro-SD card, for later analysis.

To read the full article, please select the following link

The new EMG and GSR daughter cards have now been released and are officially available to Shimmer users. The EMG (Electromyogram) will prove a useful tool to existing users of the ECG daughter card with no software changes required except to support higher sampling rates, whilst readers will be familiar with the recent validation work carried out on the GSR (Galvonic Skin Response) daughter card for use in biomedical-orientated research applications.

The EMG daughter card is a highly economical wireless acquisition system for evaluating and recording the electrical activity produced by muscles using conventional disposable electrodes. The EMG works just like the existing Shimmer ECG daughter card allowing the addition of EMG measurement to existing Shimmer systems as a drop-in replacement. The EMG has low power consumption 180µA (leads connected) and a frequency range* of 5Hz-482Hz.

The GSR daughter card monitors skin conductivity between two reusable electrodes attached to two fingers of one hand and can be used in areas such as affective computing and to monitor aspects including stress, excitement, shock, and cognitive factors. The Shimmer GSR outperforms competing devices by using four digitally controlled measurement ranges. Developers use this capability to ensure accurate measurement across a variety of test subjects in real-world deployments.

The EMG and GSR daughter cards maintain an open system with no proprietary connectors, and have an open and extensible software and data format. They both capture data to the highest industry standards, and offer far superior flexibility due to wearable technology and small form factor allowing for greater usability in real world applications. Most notably, the EMG and GSR daughter cards match or often outperform competing gold standard sensor units, whilst offering better ergonomics at a cost-effective price.

A brief specification overview of the two daughter cards can be seen below:

EMG

GSR

The new daughter cards can be purchased by contacting info ‘at’ shimmer-research.com, and will be available to purchase from our online store in the coming weeks.

PRESS RELEASE

Dublin, Ireland – January 21, 2010 – The Shimmer wireless sensor platform has recently been awarded the CE mark, proving it has met EU consumer health and safety requirements for medical equipment. The CE certification also includes the ECG, EMG, and Motion capture Products.

The CE Certification coincides with the launch of the platforms new EMG (Electromyography), and GSR (Galvanic Skin Response – for testing characteristics such as stress levels) products, and reflects the platforms continued advancement of wireless sensing innovation.

Marketed and developed by Shimmer Research the Shimmer wireless sensor platform now offers a wide range of wireless sensing possibilities from physiological and kinematic motion capture to tilt and vibration sensors. Commenting on the expanding range of wireless sensors Kieran Daly, VP of Business Development at Shimmer Research noted that the company is ‘committed to driving wireless sensing innovation by providing sensors that capture data to the highest industry standards’. Indeed, this was made evident by validation work carried out on the ECG, Motion, and GSR sensors for ambulatory ECG, Temporal Gait Analysis, and GSR data capture in biomedical research settings. The information captured by Shimmer was comparable to, or outperformed larger, traditional wired units that would be considered gold standard.

Remarking on the validation results,  Daly stated that everybody at the company was ‘very pleased with the results, it’s a good representation of the quality the platform offers, and highlights how Shimmer performs against well known traditional wired units that can be costly and don’t offer the same flexibility’

To read the full Press Release, click here.

Having used Shimmer in their studies in conjunction with the TRIL (Technology for Independent Living) centre, Intel has recently published a paper on the validation of the Shimmer ECG, Motion, and GSR daughter cards. The operation of the Shimmer baseboard and daughter cards has been tested through a number of validation processes to determine the accuracy of the boards’ function and their usefulness for biomedical-orientated research applications.

ECG Validation

A number of tests were carried out to validate the Shimmer ECG daughter card as a valid tool for acquiring ambulatory ECG. The tests included the validation of the ECG amplifier and ADC performance by using calibrated input signals as well as an ECG recording from a healthy non-resting subject. Another test carried out was a 5.9 minute ECG recording containing 503 heart beats from a non-resting healthy subject during a moderate walk. The information was captured by the Shimmer ECG and also captured by a Medilog Holter monitoring system. The results indicate that the Shimmer ECG can be used to acquire ambulatory ECG from resting and non-resting human subjects for research application purposes.

Kinematic Validation

To validate the Shimmer platform for use in studies of human gait analysis, temporal gait parameters derived from a tri-axial gyroscope on the Shimmer platform were compared against those acquired simultaneously, by using the codamotion analysis system from Charnwood Dynamics Ltd., UK.

The gait of one normal healthy adult male (age 25) was measured simultaneously by using two Shimmer sensors placed on each shank and the Cartesian Optoelectronic Dynamic Anthropometer (CODA) motion analysis system. Data was recorded whilst the subject performed multiple over-ground walking and running trials along a 15-meter walkway in a motion analysis laboratory. Heel strike and toe-off characteristic points derived from the Shimmer and CODA systems were used to calculate the three temporal gait parameters listed below:

• Stride time
• Stance time
• Swing time

Results show an intraclass correlation coefficient (ICC(2,k)) [64] greater than 0.85 in stride, swing, and stance times for ten walking trials and four running trials. These results suggest that the Shimmer platform is a versatile cost-effective tool for use in temporal gait analysis.

GSR Validation

The Shimmer galvanic skin response (GSR) sensor contains an internal resistor network that works as a potential divider and provides a voltage that can be converted by the Shimmer’s ADC to a 12-bit value, used to measure external skin resistance. All skin resistance values were calculated in the Shimmer platform firmware and transmitted to a BioMOBIUS patch for real-time display and persistence to file. The sensor performance was correlated with a commercial Nexus-10 system (Mind Media BV) utilizing a series of known resistors from 10K Ω to 2.2M Ω. Shimmer GSR demonstrated an average mean percentage error of 2.3 percent versus the commercial Nexus-10 that had an average mean error of 4.1 percent.