D2.1 Requirements and Specification - CORBYS

Recommendations

Info

D2.1 Requirements and Specification and right side of the body. In the case of CORBYS, it is therefore of interest to consider ways of i) effectively combining multiple sensors in a limited number of unobtrusive devices, ii) reducing the number of cables required, or iii) introduce solutions allowing wireless communication of sensor readings. Due to user comfort, safety and unobtrusiveness requirements, this review does not consider invasive or implanted sensors (sensors puncturing the human skin), breath gas analysis sensor principles (which requires sensors or a mask in front of the mouth and nose) or body fluid analysis concepts. 10.2.1 Physiological sensor concepts Physiological sensors aim to measure aspects of the human physiology. 10.2.1.1 Heart rate The heart rate is the rate at which the heart beats. As a result of the heart contractions, blood flow through the arteries, causing a measurable pulse throughout the body. In normal situations, the heart rate and the pulse are the same, but the distinction between pulse and heart rate are made because there are situations when the heart is beating, but is not able to pump blood. The heart rate increases with the increasing physical effort, and it can also increase due to psychological stress. The electrical signals caused by the nerve signals in muscles, and in particular the signals associated with periodic contractions of the heart have been known for more than hundred years. Willhelm Einthoven was awarded a Nobel Prize in 1924 for his contributions to the field of electrocardiography, see for example Rivera-Ruiz et al (2008), see Figure 15. Figure 15: Willhelm Einthoven’s setup for measuring the ECG signals (left) and the resulting observed schematic PQRST heart signature. It is interesting to note that apart from some changes in electrode positions, the measurement is essentially the same today. While Einthoven used buckets filled with salt solutions as electrodes, the main technology development has taken place within the field of electrode technology. Skin electrode measurements are however associated with substantial problems due to physical movements, which causes large DC offset values to measurement signals due to polarisation effects as illustrated in Figure 16. Further, noises are introduced due to any muscular activity, thereby making electrode measurements more challenging for patients that are physically active. 102
D2.1 Requirements and Specification Figure 16: Illustration of the ECG signal and the effect of an abrupt mechanical disturbance. A full diagnostic (12 lead) ECG investigation, aiming at identifying heart disease conditions, employs 10 electrodes placed on the body as shown in Figure 17. Based on the mapping of the resulting curves, it is possible to identify malfunctions of the heart, for example due to infarction damaged tissue. In addition to 12 lead ECG aiming at geometrical mapping of the heart electrical signals; other diagnostic ECG measurements are done to characterise various heart rate variability conditions. Figure 17: 12 lead ECG Within CORBYS, it is not an objective to identify diagnostic heart condition information. Rather, CORBYS will employ the heart rate as an ingredient in the assessment of physical effort and possibly as a co-indicator of intended actions or psychophysiological states. As CORBYS deals with users engaged in activity, it is essential to select electrodes and measurement configurations that allow accurate monitoring while the user is active. The most common, and also potentially most accurate, method being used on active people is based on simplified ECG measurements using only 3 or 2 electrodes to extract the heart rate. In clinical applications, AgCl terminated electrodes are frequently used. These are glued, attached or patched to the patient’s skin. Silver chloride terminated electrodes can cause skin irritation with prolonged use. Further, they are associated with adhesive patches which can be uncomfortable to remove after use. Commercial heart rate monitors used in sports and fitness usually employs electrodes manufactured from elastic, conductive textile, or conductive rubber or polyurethane. The textile electrodes are backed by soft rubber or similar to increase pressure against the skin, improving electrical contact. A disadvantage with all these electrode versions is that a direct mechanical and electrical contact with the body is required at all times. The use of capacitive, “non-contact” electrodes has also been demonstrated, but these can not compete with the performance of contact electrodes at the present time. 103
Page 1 and 2:
CORBYS Cognitive Control Framework
Page 3 and 4:
D2.1 Requirements and Specification
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62: D2.1 Requirements and Specification
Page 111: D2.1 Requirements and Specification
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209:
show all

D2.1 Requirements and Specification - CORBYS

Create successful ePaper yourself

Delete template?

Save as template?