Method and device arrangement for measuring physical exercise promoting cholesterol metabolism

The invention relates to a method for measuring physical exercise promoting cholesterol metabolism on a person. The quantity and quality of exercise is typically measured with a transducer unit and measuring device system which was described in patent specifications WO 03055389 and WO 2005117703. The invention also relates to a transducer unit used in the method and a program application utilised in it.

Coronary heart diseases are the most common causes of death in industrialised countries. It has been estimated that today about 15 million people die of them annually and that this number will rise to 25 million by the year 2020 (Poulter, Heart 89, Suppl2, 2-5ii, 2003). The most important risk factors of heart diseases are disorders in lipid metabolism, high blood pressure and smoking. The most dangerous of the disorders in lipid metabolism is the increase of cholesterol concentration in blood. The rise of total cholesterol or LDL cholesterol increases the risk of cardiac death by 40-100% (Haapaπen, Niemi et al. Prev Med 28: 343- 8, 1999). The risen cholesterol concentration is commonly treated with medicines. It has been observed that a 1 mmol/L reduction in the LDL cholesterol concentration of blood decreases the risk of cardiac diseases by 25% (Heart Protection Study, Lancet 369, 7-22, 2002).

Also physical exercise decreases the risk factors of heart disease. The risk of heart disease for persons who ran for over an hour a week decreased by 42% (Taπsescu et al. JAMA 288: 1994-00, 2002). The decrease in the risk of heart disease due to exercise principally results from advantageous changes in cholesterol metabolism. Exercise causes in blood a decrease in the total cholesterol and LDL cholesterol and an increase of HDL cholesterol (Kraus et al. NEJM 347: 1483-92, 2002).

Based on the above results, exercise affects cholesterol metabolism advantageously and decreases the risks of heart diseases. However, there are no studies in prior scientific literature which would have studied the exact quantity and quality of exercise which decreases cholesterol concentrations. Prior research results are based on cross-sectional studies in which the quantity of exercise has been estimated based on questionnaires or pedometers. The cross-sectional studies do not give accurate data on exercise beneficial for an individual.

For estimating the quantity and quality of exercise, it would be useful if a personal exercise indicator was in use which would give feedback to its user on exercise performed. The pedometers give personal data on the exercises performed by an individual, but they do not consider the intensity differences of different kinds of exercise.

A training heart rate monitor, again, is a method which is based on measuring the electric operation of the heart and requires of its user the continuous use of a heart rate transmitter belt. This decreases the usability of the method.

The invention described in this application utilises acceleration transducer technology for measuring exercise.

From the PubMed database, six publications are found in which acceleration transducers are utilised and cholesterol is measured (Diab Care 27:2141 , 2004; Scan J Clin Invest 65:65, 2005; Diab Metab 32: 13 1 , 2006; Vase med 9: 107, 2004; J Ren Nutr 15:217, 2005; Circ 114:218, 2006). Yet, these cross-sectional studies have not simultaneously studied the quantity of exercise and cholesterol metabolism.

From published application WO 2005117703 are known a method and a measuring system which measures the quantity and quality of exercise by analysing changes in acceleration exerted at the body during exercises performed. The patent publication in question relates to measuring the quality and quantity of bone-mass building exercise. Fig. 1 shows the system in question in which a person carries a transducer unit attached to his/her body which unit records accelerations exerted at legs. The transducer unit analyses exercises performed and presents the results or transfers them to other data transfer devices. It is possible to save data on other characteristics of the person in the transducer unit for expanding the analysis. The method has been utilised in research publications Jamsa et al., Clin Biomech 2 1: 1-7, 2006, and Vainionpaa et a!., Osteoporosis lnt 17: 455-463, 2006.

The object of the present invention is to introduce a measuring method of exercise performed and a device arrangement related to it, by means of which an estimate can be produced on how the exercise performed by a person has affected the development of the cholesterol metabolism of the person.

The objects of the invention are achieved with a method in which the transducer unit carried by the person continuously measures and collects the values of acceleration exerted at supportive organs during the daily exercise of the person. Measured momentary maximum values of acceleration and their number in a certain time window are saved from the measurement data. By analysing the measurement data, a forecast is obtained on the impact of exercise performed on cholesterol metabolism. Based on the forecast, a recommendation on whether the exercise is sufficient or insufficient can be presented to the person exercising.

The method according to the invention for determining and presenting the development forecast of cholesterol metabolism caused by exercise performed, in which method, the transducer unit measuring acceleration data being carried by the person exercising continuously measures the acceleration peaks experienced by the supportive organs of the person exercising is characterised by that it comprises:

- a step in which classified acceleration peaks are compared to reference data measured from the normal population by acceleration measurements in which data the persons exercising are divided into four classes describing the activity of exercise which classification is made using said peak level acceleration classification;

- a step in which by using the measured acceleration peaks it is identified into which class describing the activity of exercise the person can be classified; and - a step in which based on said class describing the exercise performed it is identified if the exercise performed by the person has promoted cholesterol metabolism.

A transducer unit according to the invention which comprises a processing unit and at least one acceleration transducer and which transducer unit is arranged to be utilised in forecasting the change in cholesterol metabolism caused by exercise performed by the person exercising is characterised by the processing unit being arranged:

- to compare the classified measurement data of the person exercising obtained from the acceleration transducer to the reference data measured from the normal population, in which the persons exercising are classified using said acceleration level classification into four exercise activity classes

- to classify based on the measured acceleration peaks the person exercising into one of said exercise activity classes, and

-to present to the person having performed exercise based on said exercise activity class if the exercise performed by the person has been sufficient for promoting cholesterol metabolism,

The computer program according to the invention is characterised by that it comprises computer program code means:

- for comparing the classified acceleration peaks to reference data measured from the normal population by acceleration measurements in which data the persons exercising are divided into four classes describing the activity of exercise which classification is made using said peak level acceleration classification;

- for classifying the person by means of the measured acceleration peaks into one class describing the activity of exercise; and - for identifying if the exercise performed by the person has promoted cholesterol metabolism based on the defined class describing the activity of exercise.

The basic idea of the invention is the following: A person carries along a lightweight transducer unit which measures and records accelerations exerted on his/her supportive organs during daily or other exercise. In this context, acceleration means either an increase or a decrease in kinetic velocity, the latter of which is often called deceleration. Momentary maximum values of accelerations and their number are measured in defined time windows. As the time windows of measurement, advantageously one and seven successive days are used. Based on the acceleration data measured in these two time windows, a forecast is calculated on whether the exercise has promoted cholesterol metabolism or not. When required, the transducer unit can present the results of the first analysis made by it. The measurement data of acceleration are saved at least temporarily in the electronic part of the transducer unit. Furthermore, the measurement data can be transferred from the transducer unit to another data processing device. The method and device arrangement according to the invention are intended for controlling the person to perform correct kinds of exercise from the viewpoint of cholesterol metabolism.

An advantage of the invention is that the intensity of the exercise performed by the person having an impact on the operation of the heart and on cholesterol metabolism can be measured without fixedly attached transducers on the skin of the person exercising.

A further advantage of the invention is that from the measurement data of acceleration exerted on the supportive organs experienced by the person during the exercise can be made a forecast on whether the exercise performed has promoted cholesterol metabolism.

The invention will now be described in detail. The description refers to the accompanying figures in which

Fig. 1 shows by way of an example the parts of a device arrangement used in the estimation of cholesterol metabolism according to the invention,

Rg. 2a shows the connection between the activity of exercise performed and total cholesterol values,

Fig. 2b shows the connection between the activity of exercise performed and LDL cholesterol values, Fig. 3 shows by way of an example a transducer unit used in the estimation of cholesterol metabolism according to the invention, and

Fig. 4 shows a flow chart by way of an example of an estimation method of cholesterol metabolism utilising the device arrangement according to the invention. Fig. 1 shows by way of an example a measurement arrangement of cholesterol metabolism according to the invention. A transducer unit 2 records an acceleration peak every time the leg of a person 1 hits the ground. The kind of exercise used defines the quantity of the maximum value of the recorded acceleration peak. The repetition frequency of the acceleration peaks also describes the kind of exercise used. These measurement variables can advantageously be utilised in the classification describing the activity of exercise performed which in the transducer according to the invention is utilised in compiling a cholesterol metabolism forecast.

By means of the invention according to Fig, 1 , it is possible to examine the quantity and quality of exercises performed having an advantageous impact on cholesterol metabolism. The target is achieved by continuously recording accelerations exerted at the legs during daily exercise performed by the person T with the transducer unit 2 including an acceleration transducer. The results are

advantageously analysed with the transducer unit 2 presented in published application WO 2005117703. The recorded results are visible either in the transducer unit 2 used by the person or in an external data processing device 3. Based on the received measurement feedback, the person 1 can change the quantity and quality of his/her exercise so that it has an advantageous impact on cholesterol metabolism.

The experimental results obtained by the method are shown in Figs. 2a and 2b. The results are based on a 12-moπth follow-up carried out on 65 women. Half of the women took part in intensified exercise and the other half continued their previous kinds of exercises. Figs. 2a and 2b are divided into five ranges of acceleration which typically correspond exercise including walking (0.3-1.0 g), stepping (1.1-2.4 g), jogging (2.5-3.8 g), running (3.9-5.3 g) and jumping (5.4- 9.2 g).

Based on the results given by the transducer, the women were divided into four subgroups (quartiles) in each acceleration range, the 1 ^st quartile of which represented the persons having performed minor exercises and the 4 ^th quartile the persons having performed major exercises. From Figs. 2a and 2b, it is seen that, on the acceleration ranges corresponding stepping or jogging, running or jumping, the total cholesterol and the LDL cholesterol were 0.4-0.6 mmol/i lower in the most active quartile (quartile 4) than in the least active quartile (quartile 1 ). These differences were statistically significant. Statistically significant differences were also found in the 2 ^nd and 3 ^rd quartiles. The results show that the quantity and quality of exercise measured by this method significantly explain the advantageous changes of cholesterol metabolism. With prior-art methods, this has not been demonstrated.

Fig. 3 shows an advantageous embodiment of the transducer unit 2 according to the invention. The transducer unit 2 advantageously comprises an energy source 24, such as a battery or an accumulator. The electric elements contained by the transducer unit 2 get the energy required for their operation from this energy source 24. There is at least one acceleration transducer 21 in the transducer unit 2. By using more than one transducer 21 , accelerations can be measured in two or three dimensions, when required. The measurement range of a single acceleration transducer is advantageously ±10 g.

The measurement data of the acceleration transducer 21 are transmitted to a central processing unit (CPU) 22 of the transducer unit 2, which also advantageously comprises a certain amount of memory used by the processing unit 22 for saving various program applications and the results of performed acceleration measurements according to the invention. The processing unit 22 advantageously performs an analysis of the measured acceleration data by first analysis means according to a program application saved in its memory, suitable for estimating cholesterol metabolism.

The processing unit 22 also communicates with a data transfer component 23. By means of this data transfer component, a data transfer connection can be set up to the external data processing device 3. The data transfer component 23 advantageously supports at least one data transfer method. Advantageous methods used in data transfer include infrared (IR) technique, Bluetooth technique, WLAN technique and various time or code division data transfer techniques used in cellular networks.

The transducer unit 2 also advantageously comprises indicator means 25 e.g. for indicating the result of the first analysis specific to the time of use. By means of the indicator means, it is possible to communicate to the user of the transducer unit 2 e.g. simple messages of ON/OFF type if the exercise performed has promoted cholesterol metabolism. The indicator means 25 can be e.g. LEDs of different colours. If the objective of the exercise performed is reached, a LED of certain colour burns. Alternatively, the indicator means 25 can comprise a sector- shaped display the increase of the sector angle of which shows the result of the exercise performed compared to the set objectives. The information presented by the indicator means 25 can be either day-specific or week-specific information. The user can advantageously modify the way in which the information is presented to make it support his/her personal exercise best.

The transducer unit 2 according to the invention can also be part of some other device which the person being monitored carries along. An example of such a device, in which the transducer unit 2 according to the invention can be integrated, is a terminal device used in cellular networks or a measuring device of bone-mass building exercise known from publication WO 2005117703. Then, at least one acceleration transducer and a computer program implementing the method steps according to the invention have been installed in these devices to provide the operation according to the invention.

Single maximum values of acceleration measured in the transducer unit 2 can be analysed in estimating cholesterol metabolism e.g. in the following way. In order for exercise to have a promoting impact on cholesterol metabolism, exercise should strain the heart at a sufficient level, sufficiently long at one exercise time and, furthermore, the exercises should be regularly repeated. Because of this, the transducer unit 2 used in the estimation of cholesterol metabolism according to the invention advantageously analyses the intensity of exercise by means of measured acceleration peaks, the duration of exercise as a daily measurement, and the regularity of exercise as a weekly measurement.

The maximum accelerations measured in the transducer unit 2 according to the invention are advantageously classified using the peak values of measured acceleration into three acceleration level classes which have an advantageous impact on cholesterol metabolism according to studies. Acceleration level class > 1.1 g corresponds walking, acceleration level class > 2.3 g corresponds jogging, and acceleration level class > 3.6 g includes both running and jumping. Advantageously, each above-mentioned acceleration level class has the same weighting coefficient in the cholesterol metabolism analysis according to the invention. The classification used in the analysis is presented in Table 1.

Table 1 : Eξxercise analysis table

For each determined acceleration level class, the number of measured acceleration peaks belonging to the class required in both a day and a week if exercise is desired to promote cholesterol metabolism has been defined. The

numbers of the acceleration peaks in Table 1 describe the duration of each kind of exercise either in a day or a week.

An additional condition for the number of measured daily acceleration peaks is advantageously also that only 45% of the number of acceleration peaks required a week is considered in each acceleration level class in calculating the daily acceleration peaks. This means that of acceleration peaks measured during one day the analysis observes, at the most, 2287 acceleration peaks in acceleration level class > 1.1 g, 646 acceleration peaks in acceleration level class > 2.5 g, and 246 acceleration peaks in acceleration level class > 3.9 g. By this procedure, it is ensured that it is not possible to attain the required number of weekly acceleration peaks at one exercise time. The used procedure means in practice that the exercise should be repeated in different days in a time window of one week. This sufficiently straining and repeated quantity of exercise has been identified in studies to promote cholesterol metabolism.

Above, the exercise activity of the person was analysed using measured peak values of acceleration. The measured acceleration peaks can also be analysed based on their shape. Then, it is possible to utilise in estimating the change of cholesterol metabolism, in addition to the mere number (N) of the peaks or instead of it, also the width of the acceleration peak, the area of the acceleration peak, the area of the acceleration peak squared, the ascending time of the acceleration peak, or the ascending angle of the acceleration peak. Utilising these parameters, the person can be classified in one of the exercise activity classes described above.

Another possible way to classify the person into an exercise activity class is to calculate the area defined by the acceleration level graph drawn up from the measurement results advantageously in the range 1-9 g. In this graph, the variables are the acceleration peak classes (x axis) and the relative number of the occurrences of a certain acceleration peak class (y axis). The area calculated from the graph is then compared to the area obtained from the measurements of the corresponding normal population. If the area calculated from the graph of the exercising person exceeds a certain threshold value (the result of the normal population), the person belongs to the highest exercise activity class. Then, the exercise performed by the person has had an advantageous impact on cholesterol metabolism.

A third possible way of classifying the exercise activity is to convert the measured numbers (N) of the acceleration peaks in a certain acceleration level class to logarithmic (log(N)), whereby the straight line y = ax + b can be mathematically fitted as the graph of acceleration level classes. The constants a and b are compared to a straight line which has been obtained from the measurement results of normal population of the same age and sex. The normal population does not practise intensified exercise. If the constants a and b of the person being monitored exceed certain threshold values calculated on the basis of the normal population, the person can be classified into the most active exercise activity class.

Fig. 4 shows the main steps included in the forecast method of the development of cholesterol metabolism according to the invention as a flow chart example. By means of the method, it is possible to create an indication as to whether the exercise performed by the person has had a positive impact on cholesterol metabolism or not.

The collection of acceleration measurement data is started in step 41. In principle, the measurement is continuously in operation after this. This is possible because the person 1 being measured equips himself/herself with the transducer unit 2 according to the invention. The transducer unit 2 can be fastened e.g. to a belt. In step 42, while the person is exercising, the transducer unit 2 continuously collects various information on the accelerations experienced by the person, their absolute maximum values, occurrence frequencies and numbers. The numbers of the acceleration peaks are collected both day- and week-specifically.

In step 43, the measured acceleration data are advantageously classified once a day utilising the classification arguments presented in Table 1. The classification of acceleration data according to the invention is advantageously performed per both the concluded day and six days preceding it. In the classification, each measured acceleration peak of the range of over 1.1 g is classified in one of the three acceleration level classes of Table 1. Each measured acceleration peak increases the number (N) of the acceleration peaks included by its own acceleration level class with one.

In step 44, the classified acceleration level data are processed with a cholesterol metabolism algorithm according to the invention. The analysis utilises the daily and weekly numbers of acceleration maximum values shown in Table 1. Still, the

analysis advantageously observes the fact that in the calculation of daily acceleration peaks only 45% of the threshold value of acceleration peaks used in the calculation of weekly acceleration peaks shown in Table 1 is observed.

The result of the analysis made is compared in step 45 to the daily threshold value of exercise having an advantageous impact on cholesterol metabolism. If the comparison in step 45 gives a negative result, it means that the exercise activities of the person have not been sufficient to promote cholesterol metabolism. Then, the person is given a prompt in step 48 to increase exercise. This prompt 48 can also advantageously include an example of what kind of exercise and how much would be necessary.

If the result of the comparison in step 45 is that the daily exercise has been sufficient from the viewpoint of the positive development of cholesterol metabolism, next is step 46 in which an analysis is performed utilising the measurement data of seven successive days. If the seven-day analysis made in step 46 shows that the exercise in the period in question has not been sufficient to promote cholesterol metabolism, in step 48 is given a prompt to increase exercising.

If the seven-day analysis made in step 46 shows that the exercise in the period in question has been sufficient to promote cholesterol metabolism, in step 47 is given an indication of it for the performer of exercise. The indication can be a simple notice of ON/OFF type or it can be given as a message transmitted by a communication device in the form of sound, text or image.

Regardless of the result of the analyses in steps 45 and 46, the collection of acceleration measurement data continues in step 49 when a new measurement day begins. In practice, the measurement process returns to step 42.

In an advantageous embodiment of the invention, when the memory 22 of the transducer unit 2 starts to fill up, the results of the comparisons 45 and 46 can be transferred via a suitable data transfer connection to the data processing device 3 having a larger data processing capability. In the data processing device 3, a new, more accurate estimate for the development of cholesterol metabolism can be made utilising a longer measurement history. A more detailed second analysis of the measurement data is thus advantageously performed in the data processing device 3 by second analysis means. They advantageously utilise the personal

data saved in the data processing device. The personal data include the analysis results of all the previously saved exercise data. If this more detailed analysis shows that it would be advantageous for the person to perform certain kind of additional exercise in order to reach his/her cholesterol metabolism objective, a recommendation on this can be drawn up for him/her.

The method steps according to the invention described above can advantageously be implemented by two separate computer programs. The first computer program is saved in the transducer unit 2 and the second one in the data processing device 3. The first computer program application saved in the transducer unit 2 can also be utilised separately. If long-term monitoring of cholesterol metabolism is wanted to be implemented, another computer program in the data processing device 3 is also required.

Some advantageous embodiments according to the invention were described above. The invention is not limited to the arrangements described. The objects of the measurement of acceleration data presented in the description are only examples of the objects in which the method according to the invention can be applied. The inventive idea can be applied in numerous ways within the scope defined by the claims.