Abstract:
A portable user-specific performance measuring system comprises a quality unit which receives a measurement signal and measures the quality of the measurement signal, and a presentation unit which receives from the quality unit quality data indicating the quality of the measurement signal and presents the quality of the measurement signal on the basis of the quality data.

Description:
FIELD 
       [0001]    The invention relates to a portable, user-specific performance measuring system, a related method for data transmission of signal quality and a corresponding computer program. 
       BACKGROUND 
       [0002]    It is important to measure the functioning of the organ system and the movement of a person when training for an athletic performance, for example. The heart rate of a person, for instance, can be measured with a portable device that comprises a measuring belt to be fastened on the chest with an elastic belt and a heart rate receiver to be fastened on the wrist like a watch, which heart rate receiver serves as a receiver of measurement data and may process the measurement data. 
         [0003]    The measuring belt consists of a flexible piece to be fastened on the chest and having a sensor for measuring an ECG signal. The sensor comprises two measuring electrodes that settle against the skin and are connected to an ECG detecting block. Instead of ECG measurement or in addition to it, it is possible to use several other sensors to measure the state of the organ system or movement of the user. These include acceleration sensors that provide information on the movements of the user. 
         [0004]    A transmitter in the measuring belt or some other sensor may wirelessly transmit measurement data to the measurement data receiver fastened to the wrist of the user for processing therein. From the measuring belt or wrist receiver, the measurement data may be transmitted on to a computer or some other corresponding receiver for further processing. 
         [0005]    However, there are problems associated with the measurement. Sweating during an athletic performance moistens the skin and improves its electrical conductivity, whereas at the beginning of the athletic performance the skin may be dry and have poor conductivity. In the latter case, the contact of the measuring electrodes of the measuring belt with the skin may be weak, which deteriorates the quality of the measurement signal received from the electrodes. There are also several other reasons affecting the contact between the skin and the electrodes, such as the tightness of the measuring belt, due to which the user cannot know how good or bad the contact is. It is also possible that a proper measurement signal is not received at all due to the poor contact, the measurement signal being only noise. Since the measuring result depends on the contact and the consequent quality of the measurement signal, measuring the real functioning of the user&#39;s organ system may be insecure or fail altogether, particularly at the beginning of an athletic performance. 
       BRIEF DESCRIPTION 
       [0006]    An object of the invention is to implement a method for measurement of signal quality for a performance measuring system. This is achieved by a data transmission method during the performance of which a sensor of a portable user-specific performance measuring system is intended to be in contact with a user to generate a measurement signal relating to the functioning of the user&#39;s organ system. The method comprises receiving quality data of the measurement signal generated by the sensor; and presenting the quality of the measurement signal to the user on the basis of the quality data. 
         [0007]    A further object of the invention is a portable user-specific performance measuring system arranged to generate a measurement signal relating to the functioning of a user&#39;s organ system when the performance measuring system is being used by the user. The performance measuring system comprises: a presentation unit arranged to receive quality data indicating the quality of the measurement signal and to present the quality of the measurement signal on the basis of the quality data. 
         [0008]    Yet another object of the invention is a computer software product comprising encoded instructions which, loaded on a portable user-specific performance measuring system, form a computer process controlling the operation of the performance measuring system, the performance measuring system being intended to measure the functioning of a user&#39;s organ system. The computer process comprises receiving the quality data of a measurement signal generated by a sensor; and presenting the quality of the measurement signal to the user on the basis of the quality data. 
         [0009]    Preferred embodiments of the invention are described in the dependent claim. 
         [0010]    Several advantages are achieved with the method and performance measuring system according to the invention. The quality of the measurement signal can be presented to the user, and the user can, on the basis of these data, take measures to improve the contact and the quality of the measurement signal, if required. 
     
    
     
       LIST OF FIGURES 
         [0011]    The invention will now be described in greater detail in connection with preferred embodiments, referring to the attached drawings, in which 
           [0012]      FIG. 1  shows a measuring unit; 
           [0013]      FIG. 2  shows a measuring unit provided with a processor; 
           [0014]      FIG. 3  shows a measuring unit in which a processor modifies both the measurement signal and the quality data; 
           [0015]      FIG. 4  shows a measuring unit provided with a presentation unit; 
           [0016]      FIG. 5  shows a quality unit controlling a presentation unit; 
           [0017]      FIG. 6  shows a performance measuring system comprising a measuring unit and a central processing unit; 
           [0018]      FIG. 7  shows a user using a performance measuring system; 
           [0019]      FIG. 8  shows a central processing unit showing that the quality of the measurement signal is sufficiently good; 
           [0020]      FIG. 9  shows a central processing unit showing the quality of the measurement signal with a bar; 
           [0021]      FIG. 10  shows a measuring unit showing the quality of the measurement signal with two LEDs; 
           [0022]      FIG. 11  shows a measuring unit showing the quality of the measurement signal with a row of LEDs; and 
           [0023]      FIG. 12  shows a flow chart of the method. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0024]    First, let us examine measurement of the signal quality with reference to  FIGS. 1 to 3 . The performance measuring system  100  may comprise a measuring unit  102 , which may comprise one or more sensors  106  measuring the functioning of one or more organ systems, a preamplifier  108 , a quality unit  110  and a communication unit (CO# 1 )  112 . 
         [0025]    The sensor  106  may measure the functioning of the organ system. The functioning of the organ system may be represented by the heart rate etc. 
         [0026]    When measuring the heart rate, for example, electrodes  106 A,  106 B of the sensor  106  may detect the voltage generated by the electrical activity of the heart muscle from the user&#39;s skin surface and generate a measurement signal, such as an ECG signal (ECG, electrocardiogram) representing the electrical activity of the heart muscle. 
         [0027]    The measurement signal may be fed from the electrodes  106 A,  106 B to the ECG preamplifier  108 , which can amplify the measurement signal  120  generated by the sensor  106  and feed the amplified measurement signal to the communication unit  112  and quality unit  110 . The preamplifier  108  may comprise several amplification stages. ECG data, for example, may be processed in such a way that they comprise the ECG as such, a part of the ECG and/or timing data of the heart rate. The timing data may contain a timing pulse representing a predetermined part of the ECG. 
         [0028]    To provide quality data, the quality unit  110  may measure the amplitude of the measurement signal  120 . As a quality-representing property, the quality unit  110  may alternatively or additionally measure from the measurement signal the signal-to-interference ratio or the shape of the measurement signal  120  in relation to a predetermined reference shape. Here, high amplitude is good, meaning a voltage of more than 1 mV from peak to peak between the electrodes  106 A,  106 B. A good signal-to-interference ratio also means good quality. In this case, the low-frequency (e.g. below 10 Hz) interference has been filtered out and the measurement may be carried out in the frequency range of 10 Hz to 30 Hz. Also, the closer to the predetermined reference shape the measurement signal shape is, the better the quality of the measurement signal can be considered. The reference signal may be generated from the user&#39;s own measurement signal before the actual performance measurement. To generate the reference signal, the measurement may be carried out under predetermined conditions, such as in rest. The reference signal may be measured only once, repeatedly from time to time or every time before the actual performance measurement. The comparison may be visual or done by means of a computer program. The measurement signal shape and the predetermined reference shape can be compared by means of correlation, for example. 
         [0029]    The communication unit  112  may comprise several successive amplification stages, such as an AGC (Automatic Gain Control) amplifier and a power amplifier. The communication unit  112  transmits as wireless data transmission a signal comprising measurement data and quality data. The measuring unit  102  may also be a transceiver, in which case the communication unit  112  may wirelessly receive signals sent by a predetermined communication party. Wireless communication may be based on magnetic pulses or radio-frequency electromagnetic radiation. The frequency of radio-frequency data transmission may be 2.4 GHz, and the data transmission may be digital data transmission, the data packet of which may have a separate field for quality data. 
         [0030]      FIG. 2  shows an embodiment of the measuring unit  102  of the performance measuring system  100 . The measuring unit  102  may also comprise a processing unit (PU)  114 , which may convert a measurement signal  120  to be transferred to the communication unit  112  into a digital form and process it digitally in a desired manner. It may be filtered and/or encoded, for example. 
         [0031]    The processing unit  114  may be implemented by using analogue circuits, ASIC circuits (Application Specific Integrated Circuit), a digital processor, memory and computer software. The processing unit  114  may form a part of the computer of the performance measuring system  100 . 
         [0032]    As presented in  FIG. 3 , the measuring unit  102  may comprise a processing unit (PU)  114  that may convert quality data  140  provided by the quality unit  110  as well as measurement data, which are to be transferred to the communication unit  112 , into a digital form and process these data as desired by means of digital signal processing. They may be filtered and/or encoded, for example. 
         [0033]    Let us now examine, with reference to  FIG. 4 , presentation of the quality of the measurement signal  120  in the measuring unit  102 . The measuring unit  102  may comprise a presentation unit  136 . The presentation unit  136  may be controlled, according to the quality encoded in the quality data  140 , by means of a processing unit  114  that may be a processor, for instance. The presentation unit  136  may comprise a display  130  and/or a sound generator  134 . 
         [0034]    The display  130  may be, for example, an LCD display (Liquid Chrystal Display) or a row of LEDs. An LCD display may, controlled by the processing unit  114 , display the quality of the measurement signal  120  graphically and/or numerically. The processing unit  114  may also control a row of LEDs serving as a presentation unit (see  FIGS. 13 and 14 ). 
         [0035]    The sound generator  134  may be, for example, a loud-speaker or a piezoelectric crystal generating, controlled by the processing unit  114 , an audible audio signal to present the quality. The audio signal may be speech expressing the quality. Alternatively or additionally, the audio signal may be an audible call expressing quality. 
         [0036]    Let us now examine presentation of the quality of the measurement signal  120  in the measuring unit  102  with reference to  FIG. 5 . In this embodiment, the presentation unit  136  may be controlled according to the quality data of the quality unit  110  without a processing unit  114 . A processing unit  114  is not necessarily needed in this embodiment but the measurement signal  120  may be fed directly to the communication unit  112 , as in  FIG. 1 . 
         [0037]      FIG. 6  shows the measuring unit  102  and the central processing unit  104 , which may together form a user-specific performance measuring system  100 . In this example, the measuring unit  102  is according to  FIG. 1  but it may also be according to  FIGS. 2 to 4B . The central processing unit  104  may comprise a communication unit (CO# 2 )  122 , a processing unit (PU)  124 , a memory unit (MEM)  126  and a presentation unit  136 . If the central processing unit  104  comprises a presentation unit  136 , there is usually no presentation unit  136  in the measuring unit  102  but this does not have to be the case. 
         [0038]    The communication unit  112  may comprise a coil to which the preamplifier  108  may feed quality data  140  generated by the quality unit  110  and measurement data received from the sensor  106 , which measurement data correspond to, for example, the heart rate when the functioning of the heart is being measured. By means of the coil, a magnetic signal to be transmitted can be generated which contains measurement data and quality data. The coil thus forms a magnetic field varying in phase with the heart rate, the quality of the heart rate being encoded amid the magnetic field. The coil of the communication unit  112  may be in inductive communication with the coil of the communication unit  122 , for example, and thus the measuring unit  102  may transfer both the measurement data and the quality data to the central unit  104 . 
         [0039]    The communication unit  112  of the measuring unit  102  may also transmit the measurement data and quality data to the communication unit  122  of the central processing unit  104  as electromagnetic radiation. 
         [0040]    The communication unit  122  of the central processing unit  104  may receive the measurement data and quality data and feed these data to the processing unit  124 , which may execute a computer process according to the encoded instructions stored in the memory unit  126 . 
         [0041]    The processing unit  124  may be implemented by using analogue circuits, ASIC circuits (Application Specific Integrated Circuit), a digital processor, memory and computer software. The processing unit  124  may comprise a part of the computer of the performance measuring system  100 . 
         [0042]    By means of its communication unit  112 , the measuring unit  102  may transmit to the communication unit  122  of the central processing unit  104  not only the measurement data but also the quality data that indicate the quality of the measurement signal  120 , measured by the quality unit  110  of the measuring unit  102 . The communication unit  122  may feed the quality data  140  to the processing unit  124 , which controls, similarly to the processing unit  114  in the case of  FIG. 4A , the presentation unit  136  to present the quality of the measurement signal  120 . If no processing unit  124  is in use, it is possible that the presentation unit  136  is controlled by the communication unit  122  on the basis of the quality data  140 . 
         [0043]    With reference to the embodiment shown in  FIG. 7 , the measuring transmitter  102  may be a transmitter belt  202  fastenable around a user&#39;s  200  chest. By means of magnetic pulses or radio-frequency electromagnetic radiation, the quality data  140  may be transmitted from the transmitter belt  202  for example to a wrist-held device  204 , which may be the same as the central unit  104 . Instead of on the wrist, the device  204  may also be positioned elsewhere, for instance on a bicycle. The device  204  may receive signal corresponding to the ECG signal measured by the electrodes  106 A,  106 B and determine the quality of this signal. At its simplest, the performance measuring system may comprise only a wrist-held device  204  with electrodes. In such a case, the wrist-held device  204  corresponds to both the measuring unit  102  and the central processing unit  104 , and it may measure the functioning of the organ system and, at the same time, express the quality of the measurement signal to the user. 
         [0044]      FIGS. 8 to 11  show some examples of presenting the quality of the measurement signal.  FIG. 11  shows a central processing unit  104  (or measuring unit  102 ), on the liquid crystal display  800  of which an “OK” sign or the like is activated when the quality of the measurement signal is good for reliable operation. An inactivated “OK” sign means hereby that the quality of the measurement signal is not sufficiently good for reliable operation. Activation may mean that the “OK” sign is (clearly) perceivable, whereas an inactivated “OK” sign is not (clearly) perceivable. 
         [0045]      FIG. 9  shows an example of a bar chart  802  on the liquid crystal display  800  of the central processing unit  104  (or measuring unit  102 ), where the height of the chart part  804  representing the quality of the measurement signal changes according to the quality of the measurement signal. If the quality of the measurement signal is excellent, the part  804  representing the quality may extend to the greatest possible height (MAX). If, on the other hand, the quality of the measurement signal is weaker, the part  804  representing the quality of the measurement signal may correspondingly be lower. Instead of a vertical bar, also a horizontal bar may represent the quality of the measurement signal. Instead of or in addition to a vertical or horizontal bar, numerals  806  may represent the quality. 
         [0046]      FIG. 10  shows a LED display  810  of the central processing unit  104  (or measuring unit  102 ), comprising two LEDs. Activating the lower LED may mean that the quality of the measurement signal is too poor for reliable measurement. The lower LED may be red, for example. Activating the upper LED may mean that the quality of the measurement signal is sufficiently good for reliable measurement. The upper LED may be green, for example. 
         [0047]      FIG. 11  shows an embodiment where the quality of the measurement signal is indicated by a row of LEDs  400 . The better the quality of the measurement signal is, the more LEDs are activated. The activated LEDs radiate visible light, and the inactivated LEDs have been switched off. The scale implemented by means of LEDs may show a range of 0 to 3 mV. Each LED may correspond to 0.5 mV, for example, in which case the embodiment according to the example requires six LEDs. 
         [0048]      FIG. 12  shows a flow chart of the method. In step  900 , the quality of the measurement signal is measured. In step  902 , the quality of the measurement signal is presented to the user. 
         [0049]    The method shown in  FIG. 12  can be implemented as a logical circuit solution or a computer program. A computer program may be positioned on a distribution medium of a computer program for distribution. A distribution medium of a computer program is readable by a data processing device, and it encodes the computer program commands for controlling the operation of the performance measuring system. 
         [0050]    The distribution medium, in turn, may be a solution known as such for distributing a computer program, for example a medium readable by a data processing device, program-storing medium, memory readable by a data processing device, software distribution package readable by a data processing device, signal readable by a data processing device, data communication signal readable by a data processing device or compressed software package readable by a data processing device. 
         [0051]    Once the quality of the measurement signal has been presented to the user, the user may correct the fastening, position and/or tightness of the measuring unit  102  if he/she wishes to improve the quality of the measurement signal. Additionally or alternatively, the user may also moisten the electrodes of the measuring unit and/or the skin to improve the contact and the quality of the measurement signal. 
         [0052]    Although the invention has been described above with reference to the examples according to the attached drawings, it is clear that the invention is not restricted to them but may be modified in a plurality of ways within the scope of the attached claims.