Hok Instrument AB

Västerås, Sweden

Hok Instrument AB

Västerås, Sweden
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Rahman H.,Mälardalen University | Barua S.,Mälardalen University | Ahmed M.U.,Mälardalen University | Begum S.,Mälardalen University | Hok B.,Hok Instrument Ab
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST | Year: 2016

This paper presents a case-based classification system for alcohol detection using physiological parameters. Here, four physiological parameters e.g. Heart Rate Variability (HRV), Respiration Rate (RR), Finger Temperature (FT), and Skin Conductance (SC) are used in a Case-based reasoning (CBR) system to detect alcoholic state. In this study, the participants are classified into two groups as drunk or sober. The experimental work shows that using the CBR classification approach the obtained accuracy for individual physiological parameters e.g., HRV is 85%, RR is 81%, FT is 95% and SC is 86%. On the other hand, the achieved accuracy is 88% while combining the four parameters i.e., HRV, RR, FT and SC using the CBR system. So, the evaluation illustrates that the CBR system based on physiological sensor signal can classify alcohol state accurately when a person is under influence of at least 0.2 g/l of alcohol. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2016.


PubMed | Karolinska Institutet, Uppsala University and Hok Instrument AB
Type: | Journal: Scandinavian journal of trauma, resuscitation and emergency medicine | Year: 2015

Many patients seeking emergency care are under the influence of alcohol, which in many cases implies a differential diagnostic problem. For this reason early objective alcohol screening is of importance not to falsely assign the medical condition to intake of alcohol and thus secure a correct medical assessment.At two emergency departments, demonstrate the feasibility of accurate breath alcohol testing in emergency patients with different levels of cooperation.Assessment of the correlation and ratio between the venous blood alcohol concentration (BAC) and the breath alcohol concentration (BrAC) measured in adult emergency care patients. The BrAC was measured with a breathalyzer prototype based on infrared spectroscopy, which uses the partial pressure of carbon dioxide (pCO) in the exhaled air as a quality indicator.Eighty-eight patients enrolled (mean 45 years, 53 men, 35 women) performed 201 breath tests in total. For 51% of the patients intoxication from alcohol or tablets was considered to be the main reason for seeking medical care. Twenty-seven percent of the patients were found to have a BAC of <0.04 mg/g. With use of a common conversion factor of 2100:1 between BAC and BrAC an increased agreement with BAC was found when the level of pCO was used to estimate the end-expiratory BrAC (underestimation of 6%, r=0.94), as compared to the BrAC measured in the expired breath (underestimation of 26%, r=0.94). Performance of a forced or a non-forced expiration was not found to have a significant effect (p=0.09) on the bias between the BAC and the BrAC estimated with use of the level of CO. A variation corresponding to a BAC of 0.3 mg/g was found between two sequential breath tests, which is not considered to be of clinical significance.With use of the expired pCO as a quality marker the BrAC can be reliably assessed in emergency care patients regardless of their cooperation, and type and length of the expiration.


Hok B.,Hok Instrument AB | Pettersson H.,Autoliv | Andersson A.K.,Hok Instrument AB | Andersson A.K.,Mälardalen University | And 2 more authors.
IEEE Sensors Journal | Year: 2010

Alcolocks and alcohol screening devices are becoming commonplace, and their use is expected to grow rapidly with cost reduction and improved usability. A new breath analyzer prototype is demonstrated, with the prospects of eliminating the mouthpiece, reducing expiration time and volume, improving long-term stability, and reducing life cycle cost. Simultaneous CO2 measurements compensate for the sample dilution and un-saturated expiration. Infrared transmission spectroscopy is used for both the alcohol and CO 2 measurement, yet the entire system is contained within a small handheld unit. Experimental results are reported on the device sensitivity, linearity, resolution, and influence from varying measuring distance. The correlation between early and full-time sampling was established in 60 subjects. Basic concept verification was obtained, whereas resolution and selectivity still needs to be improved. Further improvements are expected by system optimization and integration. © 2009 IEEE.


Ljungblad J.,Hok Instrument AB | Ljungblad J.,Mälardalen University | Hok B.,Hok Instrument AB | Ekstrom M.,Mälardalen University
Sensors (Switzerland) | Year: 2016

Breath alcohol screening is important for traffic safety, access control and other areas of health promotion. A family of sensor devices useful for these purposes is being developed and evaluated. This paper is focusing on algorithms for the determination of breath alcohol concentration in diluted breath samples using carbon dioxide to compensate for the dilution. The examined algorithms make use of signal averaging, weighting and personalization to reduce estimation errors. Evaluation has been performed by using data from a previously conducted human study. It is concluded that these features in combination will significantly reduce the random error compared to the signal averaging algorithm taken alone. © 2016 by the authors; licensee MDPI, Basel, Switzerland.


Ljungblad J.,Hok Instrument AB | Hok B.,Hok Instrument AB | Ekstrom M.,Mälardalen University
IEEE ISSNIP 2014 - 2014 IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing, Conference Proceedings | Year: 2014

In screening applications there is a need for improved breath alcohol analyzers. Accuracy, specificity, usability, and through-put are critical to the device performance. Objective: To characterize the critical performance of a new contactless breath alcohol analyzer. Methods: The device is characterized by measurements using artificial breath gas and human subjects. Breath sampling is performed in ambient air using carbon dioxide as a biomarker. Results: Resolution and inter-individual variation, response time, and specificity were shown to meet the requirements of industrial standards. The feasibility of contactless measurement was demonstrated. Conclusions: The new device exhibits sufficient performance in moderately diluted breath samples. Further work is underway to reach the objective of unobtrusive breath alcohol analysis. © 2014 IEEE.


PubMed | Mälardalen University and Hok Instrument AB
Type: Journal Article | Journal: Sensors (Basel, Switzerland) | Year: 2016

Breath alcohol screening is important for traffic safety, access control and other areas of health promotion. A family of sensor devices useful for these purposes is being developed and evaluated. This paper is focusing on algorithms for the determination of breath alcohol concentration in diluted breath samples using carbon dioxide to compensate for the dilution. The examined algorithms make use of signal averaging, weighting and personalization to reduce estimation errors. Evaluation has been performed by using data from a previously conducted human study. It is concluded that these features in combination will significantly reduce the random error compared to the signal averaging algorithm taken alone.


Patent
Hok Instrument Ab | Date: 2013-08-23

A breath test system is provided comprising a sensor unit configured to sense the presence or concentration of a volatile substance present in air flowing through a predefined inlet area, and generate a signal corresponding to the concentration of said substance. Also provided is an apparatus configured to detect the presence of a person in the vicinity of said input area, and registering said presence, and configured to respond by delivering an output. This apparatus includes a unit configured to call for immediate attention of said person, and upon registration of the presence of said person, provide instructions to said person to direct an expiratory air flow towards said inlet area. An analyzer to determine breath substance concentration of said person is also provided, the determination based on said signal corresponding to the substance concentration.


Patent
HOK Instrument AB | Date: 2011-10-06

A multifunctional breath analyzer includes a receptor unit for receiving a breath sample from a test subject, a sensing unit providing a signal corresponding to the concentration of at least one volatile substance within the sample, elements for providing a signal indicative of the dilution of the breath sample, and an analyzing unit/processing unit for the identification and quantification of the volatile substance of the breath sample. The signal processing unit is configured to perform at least two different calculations for the quantification, and the signal processing unit is also configured to automatically display the result of a selected calculation, the selection being based on the signal indicating dilution.


Patent
Hok Instrument Ab | Date: 2010-02-08

A method and apparatus for breath analysis from a test person who may be incapable of delivering controlled forced expiration. Breath sampling may be essentially contactless and is provided by active air intake to measuring cell (4) via receptor (2) which exhibits concentration preserving effect based on partial reflow which prevents mixing with ambient air. The analysis is performed by IR spectroscopy, including the determination of concentration of a volatile organic substance, e g ethyl alcohol, and a physiological reference substance, e g carbon dioxide. The timing of sampling is controlled by starting command from operator, and the duration of air intake is controlled by sensor signal from the measuring cell. The apparatus includes one hand unit (1), an exchangeable receptor (2), and a docking station (3).


PubMed | Hok Instrument AB
Type: Evaluation Studies | Journal: Forensic science international | Year: 2011

Measurement of breath alcohol concentration is strongly influenced by timing and the breathing pattern. In particular, shallow expiration and hyperventilation leads to underestimation of the breath alcohol concentration. In the present study, expirograms of alcohol, water and carbon dioxide were recorded in 30 healthy individuals at various breathing manoeuvres (tidal volume, slow maximum and vital capacity expiration, breath holding, and hyperventilation). Estimation of the end expiratory alcohol concentration with the use of simultaneously measured carbon dioxide was shown to reverse the tendency of underestimation at shallow expiration and hyperventilation. These findings indicate that breath alcohol estimations can be performed at shorter expiration time and reduced expired volume compared to existing alcolocks. This is believed to improve their usability and to prevent a possible route for manipulation.

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