WO2012032501A1

WO2012032501A1 - Portable electromedical device

Info

Publication number: WO2012032501A1
Application number: PCT/IB2011/053973
Authority: WO
Inventors: Aldo Lavatelli
Original assignee: MILA GROUP Srl
Current assignee: MILA GROUP Srl
Priority date: 2010-09-10
Filing date: 2011-09-12
Publication date: 2012-03-15
Anticipated expiration: 2013-03-10
Also published as: ITMI20101654A1

Abstract

The present invention relates to a portable electromedical device (1) comprising: a first measurement section (1 1) adapted to measure biomedical/physical parameters of a patient during a session of physical/sporting activity, said first measurement section comprising at least first means (111) for measuring the cardiac frequency of the patient, second means (112) for measuring the oxyhemoglobin saturation of the patient, third means (113) for measuring the ventilation area of the patient; a second measurement section (12) adapted to measure parameters related to the patient's performance during said session of physical/sporting activity, said second measurement section comprising at least fourth means (121) for measuring the distance travelled by the patient and fifth means (122) for measuring the speed maintained by the patient; a control unit (13), operatively connected to said first and second measurement sections so as to receive first data (51) indicative of the quantities measured by said first and second measurement section, said control unit being adapted to process, on the basis of at least said first data, at least second data (52) related to the physiological condition of the patient during said session of physical/sporting activity.

Description

PORTABLE ELECTROMEDICAL DEVICE

DESCRIPTION

The present invention relates to the field of electromedical devices. In particular, it relates to a portable electronic device capable of acquiring and processing data related to physiological parameters during a session of physical and/or sporting activity.

It is known how some electromedical devices are used in the medical or sporting sector to acquire/process data indicative of some physiological parameters of a subject in order to assess state of health or physical- sporting performance.

In general, this monitoring activity is carried out while performing predefined tests, to be carried out according to methods repeatable over time.

The ability of a subject to perform a given physical exercise constitutes, in fact, an important indicator of the efficiency of the cardiovascular and respiratory system, and of the body as a whole.

Measuring this ability is important in order to assess the impact of given pathologies on the body or to develop methods to manage patients suffering from chronic pathologies. For example, assessing the level of tolerance to calibrated stress is a valid aid in order to build an accurate clinical picture for patients affected by respiratory or cardiovascular pathologies, or those who have undergone an organ transplant.

Over the years standardized methods have been developed for measuring a subject's ability to tolerate physical stress in the laboratory. These methods are often laborious and costly and are not always tolerated by the patient, especially when repeated test sessions are required.

Over the years, alternative methods have been developed to assess the physical condition of a subject under stress.

One test normally used is the maximum cardiopulmonary exercise test. This test generally provides accurate results but requires costly instruments, considerable resources in terms of trained personnel and long periods of time.

Other physical tests that are simpler, require fewer personnel and are less costly have been developed to overcome these drawbacks.

Among these are the "walking test" during which the subject walks at maximum speed for a predefined distance. This type of test is commonly used to detect pathologies compensated at rest and in rehabilitation. It is also used in maximal running, above all in sports medicine. One of these walking tests is the "Six Minute Walking Test" (or 6mWT). This test is currently widely used in order to assess the distance travelled by a subject in six minutes. This test is sufficiently reliable, given that a direct proportionality between the distance travelled during the test and the subjective condition of wellbeing of a subject has been proven experimentally.

The 6m WT is generally used to assess the treatment of patients suffering from respiratory, cardiovascular or neurological pathologies, or in rehabilitation following organ transplants. This test has the advantage of being simple, repeatable and of requiring minimum equipment, besides being well-tolerated and representative, in terms of physical stress, of the subject's daily activities, and hence of his or her quality of life.

In the 6m WT, the parameters to consider, as influencing the result of the test, should not be limited merely to measuring the distance travelled.

In the first place, it is necessary to acquire some anthropometric parameters regarding the patient, such as gender, height, weight, etc.

It is also important to know the speed and global behaviour of the patient in the manner in which he or she tackles the six minute walk, in relation to treadmill incline and increase in walking speed during the test.

A horizontal test, i.e. walking on the flat (WHO) can be assessed by the formula WHO= K * m * V * T * cos Θ . In this formula "K" is the work coefficient, "m" is the distance travelled, "V" is the walking speed, "T" is the time employed and "Θ" is the angle of inclination of the walking surface on which the test is carried out. In the case of walking on the flat the value of Θ is equal to zero.

Moreover, the value of K is normally always constant for a distance from 50 to 100 m per minute (in correlation to step length, contractile efficiency of the muscle and elastic properties of the connective tissues), and hence cannot be taken into account. Further, the parameter T is a time constant of six minutes for the 6m WT.

With these observations, in standard conditions the equation is reduced to this simplified form: WHO = m * V .

In general, the 6m WT is performed with the aid of simple instruments, such as a watch or a system for calculating the distance travelled.

This allows the distance travelled to be assessed accurately, if the test is performed on a rectilinear route, but does not allow other important information related to the gait of the subject while performing the test to be obtained. Electromedical devices normally available on the market are unable to measure, during a single test session, all the parameters required to assess the physical condition of the patient during a walking test, in particular a 6mWT.

The document WO2009/063443 describes a device for medical use and a method capable of acquiring, by mean of an electronic processor, the data obtained from measuring cardiac and pulmonary parameters. Analysis of the data is entrusted to the same electronic processor. It has been found that this device is very difficult to use during tests, such as the 6m WT, in which extensive analysis of the measured parameters is required.

The document WO2006/105341 describes a device for monitoring the physical condition of a subject.

In an embodiment, it comprises a pedometer to assess the distance travelled and a microprocessor to process signals related to physiological parameters coming from external measurement devices. A man-machine interface allows viewing of the information obtained through processing with a microprocessor.

This device is not suitable for performing dynamic tests such as the 6mWT, as it requires numerous supporting elements.

The document W098/53732 describes a portable apparatus for measuring metabolic parameters of a subject during physical activity.

This apparatus has a relatively complex structure which makes it difficult to use in dynamic tests.

Moreover, it does not include processing of the parameters measured and assessment of the resulting test. All data are sent, via a transmitter, to a remote processing unit.

The apparatus does not comprise, finally, devices for measuring the parameters necessary to carry out the 6m WT or other stress tests.

The document US2008/0200308 describes a portable kit for performing cardiopulmonary tests. A mouthpiece, or mask, is provided to measure the patient's breathing connected to an external control unit.

It has been found that this device, which moreover does not process the data measured during the test, cannot be used while carrying out stress tests, such as the 6mWT.

From the above it is evident that in the market there is the need to provide a portable electromedical device with a high level of versatility, capable of measuring a large number of physiological data during a physical test to be taken by a subject, in particular during a

6mWT. Therefore, an object of the present invention is to provide a portable electromedical device capable of measuring a large number of biomedical/physiological parameters while performing a physical-sporting activity, with particular reference to the 6m WT.

Another object of the present invention is to provide an electromedical device which allows reliable, repeated and frequent measurement of the subject's performance during the physical- sporting activity, hence suitable for maximal running tests with programmed time or distance or fixed rate step tests (for example to calculate the IRI - Immediate Recovery Index).

A further object of the present invention is to provide an electromedical device capable of processing the data measured to provide useful information for assessing the performance of the subject in relation to the test performed.

Another object of the present invention is to provide an electromedical device with relatively simple structure and function, which can be easily and rapidly applied to, and is well-tolerated by, the subject (in relation, for example, to characteristics of lightness) and which can be produced economically at industrial level.

In accordance with the present invention, the aforesaid objects are achieved by means of a portable electromedical device according to claim 1 proposed hereunder.

The aforesaid objects are achieved by a portable electromedical device characterized in that it comprises:

a first measurement section adapted to measure biomedical/physical parameters of a patient during a session of physical/sporting activity, said first measurement section comprising at least first means for measuring the cardiac frequency of the patient, second means for measuring the oxyhemoglobin saturation of the patient, third means for measuring the ventilation area of the patient;

a second measurement section adapted to measure parameters related to the patient's performance during said session of physical/sporting activity, said second measurement section comprising at least fourth means for measuring the distance travelled by the patient and fifth means for measuring the speed maintained by the patient;

a control unit, operatively connected to said first and second measurement sections so as to receive first data indicative of the quantities measured by said first and second measurement section, said control unit being adapted to process, on the basis of at least said first data, at least second data related to the physiological condition of the patient during said session of physical/sporting activity.

Further characteristics and advantages of the present invention will be more apparent from the description of preferred embodiments, shown by way of non-limiting example in the accompanying drawings, wherein:

Fig. 1 is a schematic block diagram of the electromedical device according to the present invention;

Fig. 2 is a perspective view of the control unit of the electromedical device according to the present invention;

Fig. 3 is a perspective view of the third means for measuring the ventilation area of the electromedical device according to the present invention;

Fig. 4 is a perspective view of the first and of the second measurement means, contained in a single device constituted by a pulse oximeter, in the electromedical device according to the present invention.

With reference to the aforesaid figures, the device 1 according to the present invention comprises a first measurement section 1 1 adapted to measure biomedical/physiological parameters of a patient during a session of physical/sporting activity, a second measurement section 12 adapted to measure parameters related to the patient's performance during said session of physical/sporting activity and a control unit 13, operatively connected to said first 1 1 and second 12 measurement sections.

The first measurement section 1 1 comprises first means 1 11 for measuring cardiac frequency, second means 1 12 for measuring oxyhemoglobin saturation and third means 1 13 for measuring the patient's ventilation area.

The first means 1 1 1 for measuring cardiac frequency preferably comprise a pulse oximeter with finger or ear measurement, which can in any case perform measurement in both modes. Also the second means 1 12 for measuring oxyhemoglobin saturation preferably comprise a pulse oximeter.

According to the embodiment described here, both the first measurement means 111 and the second measurement means 1 12 are advantageously represented by the same pulse oximeter 212 (Fig. 4).

The third means 1 13 for measuring the ventilation area comprise an oral-nasal airflow sensor. This is preferably produced using a thermocouple.

This thermocouple allows measurement of the patient's actual respiratory frequency and, by means of an integral calculation, subsequent calculation of the ventilation area, i.e. of the quantity of air effectively inhaled and exhaled by the patient at each sampling instant.

It must be noted that calculation of the ventilation area does not derive from a direct measurement of the volume inhaled and exhaled but is calculated on the basis of the measurement of respiratory frequency, amplified if necessary. In particular, calculation is performed through the operation of integration of the respiratory frequency sampling, as described hereunder. In fact the ventilation area would ideally correspond to the volume ventilated by the patient only if this latter were measurable at all times by means for measuring this volume. Usually, however, the inhaling and exhaling phases, in patients with pulmonary problems, do not allow measurement of small changes in phase and, therefore, do not allow measurement of small quantities of volume breathed. Instead, calculation of the ventilation area, through effective measurement of the frequency, allows more accurate and reliable calculation of the quantity of V0₂. The second measurement section 12 comprises fourth means 121 for measuring the distance travelled by the patient and fifth means 122 for measuring the speed maintained by the patient during performance of the test.

The means 121 for measuring the distance travelled preferably comprise a pedometer, capable of measuring the number of steps taken and therefore, by interpolating these with the average length of one step, the distance travelled by the subject.

The means 122 for measuring the speed maintained by the patient during the test are advantageously represented, in the embodiments described herein, by the same pedometer device used as means 121 for measuring the distance travelled.

In this case, by interpolating the data of the distance travelled with the time elapsed, the instantaneous speed and the average speed maintained by the subject during the test are calculated.

The distance and the speed can also be measured by means of other systems, such as an infrared transmitter/receiver connected to the ankles, inertial motion sensor or accelerometer, a GPS system and a radar system, which may be present at the same time.

Further, the second measurement section 12 comprises, according to the embodiment described herein, a barometric sensor capable of measuring, at all times during sampling, the pressure, temperature and humidity of the environment in which the test is performed.

The control unit 13, operatively connected to the measurement sections 11 and 12, preferably comprises a programmed or programmable microcontroller.

This latter is able to receive the first 51 indicative of the quantities measured by said measurement sections.

The control unit 13 is capable of processing, on the basis of at least the first data 51 , second data, optionally pre-processed, related to the physiological condition of the patient during the session of physical/sporting activity performed.

The control unit 13 is also capable of receiving third reference data 53 for the session of physical/sporting activity which preferably comprise anamnestic data provided by the patient, data indicative of the environmental conditions in which the test session takes place, data indicating the threshold and alarm values for the patient's physiological parameters and data related to the patient's physiological conditions in previous sessions of physical/sporting activity, if any.

The third data 53 can also comprise information related to the type of test to be performed with the relative specifications, such as time, distance, type of route and so forth.

The third reference data 53 are preferably sent from a first remote electronic processing device 21 operatively connected to the control unit 13.

The control unit 13 is also capable of processing fourth data 54 for interpolation of the first, second and third data received previously.

The control unit 13 is also capable of generating alarm signals 55 in relation to the fourth data 54 processed previously, if these latter are not within intervals defined by the third data 53. The alarm signals 55 concern, for example, indication of a particular operating condition of the device 1 , indication of the start and finish of the test time and, optionally, physiological threshold values exceeded by the subject.

The first electronic processing device 21, operatively connected to the control unit 13, is also capable of processing the third data 53 on the basis of anamnestic data provided by the patient, data indicative of the environmental conditions in which said session takes place, data indicative of the threshold values for the patient's physiological parameters and data related to the patient's physiological condition in previous sessions of physical -sporting activity undergone by the patient.

The control unit 13, according to the embodiment being described, is further provided with an electronic data memory device .

This device is capable of permanently memorizing the first data 51, the second data 52, the third data 53 and the fourth data 54 and comprises, in the embodiment being described here, an electronic memory of "Secure Digital" (SD) type.

In any case, the aforesaid memory device can comprise and use any type of media for memorizing data.

The data memorized by the control unit 13 can also be sent to further devices operatively connected to the portable electromedical device 1 according to the present invention.

Specifically, the control unit 13 is capable of sending these data to a second remote electronic processing device 22 operatively connected to said control unit. Preferably, the first and second electronic control devices 21 and 22 are included in or constituted by a single remote electronic processing device operatively connected to the control unit 13.

The electronic processing device 22 is also capable of creating and updating a historical archive of the data related to the patient's physiological condition, on the basis of data sent by the control unit 13 to this remote electronic processing device 22.

The portable electromedical device 1 according to the present invention is completed by a user interface 131 , accessible to the patient during said session of physical/sporting activity. By means of this user interface, the patient is capable of initializing, performing and terminating the test in a completely autonomous manner, without performing further set up operations.

The user interface 131 is also adapted to transmit the alarm signals 55 to the user.

With reference to Fig. 2, the control unit 13 is preferably constituted by a casing in plastic material, positioned inside which is the integrated circuit with which the microcontroller is operatively connected, a set of batteries, optionally rechargeable, for mobile use, and a module for data transmission and reception in telemetry toward the electronic processing device 21 and/or the electronic processing device 22, if constituted by distinct elements. The control unit 13 is also advantageously provided with a flow data amplifier, capable of managing the data received from the third means 1 13 of measuring the ventilation area.

Preferably, the control unit 13 comprises a further integrated circuit, operatively connected with the microcontroller and adapted to manage the cardiac frequency and oxyhemoglobin saturation data measured by the first means 111 for measuring the cardiac frequency and by the second means 112 for measuring the oxyhemoglobin saturation.

With reference to Fig. 3, the flow sensor of the third measurement means 1 13 is advantageously produced by means of an oral-nasal thermocouple provided with three measuring elements 123, 123 ',123", one for each nostril and one for the mouth.

These measuring elements are also provided with protection means 133, 133', 133" affixed to the measuring elements 123, 123', 123".

The aforesaid protection means are produced by means of a shell affixed in proximity of the ends of the measuring elements 123, 123 ',123" positioned to correspond with the nostrils and mouth.

The shell prevents substantial penetration of external air at a different speed to that inhaled/exhaled by the nostrils and by the mouth, such as air generated by external currents if the test is performed in an outdoor environment or by other disturbing elements (fans, air conditioner vents, etc.). This air could in fact falsify the measurement during performance of the test.

The portable electromedical device 1 according to the present invention is placed in operating phase by means of switching on and inserting the electronic memory medium inside the control unit 13.

The health operator, or other operator, connects the device 1 to the first electronic processing device 21.

In this manner, the third reference data 53 for the session of physical/sporting activity is transferred from this latter to the device 1.

The portable electromedical device 1 is then positioned on the subject. This latter starts the test autonomously by pressing a start key located on the control unit 13.

The test starts with calibration of the step, if required, obtained by means of a "warm-up" phase. With this "warm up" phase, the fourth means 121 for measuring the distance travelled by the subject and the fifth means 122 for measuring the speed maintained by the subject while performing the test are calibrated. Preferably, these aforesaid means are included inside the pedometer, allowing assessment of the average length of the subject's step.

This is followed by a "reference base" phase lasting three minutes or more. Upon indication of alarm signals 55, in relation to continuous monitoring during the "reference base" phase, emitted by the control unit 13 the decision can be made whether to continue with the test or to stop if the subject is not in suitable condition to undergo physical stress.

The same signals are advantageously viewed through the user interface 131 positioned on the control unit 13.

At the end of the "reference base" phase, the device 1 autonomously emits a further signal 55. In this way, the subject is informed that the calibration phase has ended and that the reference base values have been acquired, with simultaneously start-up of the actual test.

In the subsequent six minutes of performance of the test, the portable electromedical device 1 analyzes and records the first data 51 indicative of the quantities measured during the walk starting from the subject's first step.

The first data 51 are measured by the first 11 1, second 112, third 113, fourth 114 and fifth 115 measurement means and processed by the microcontroller placed inside the control unit 13, generating and recording second data 52 related to the patient's physiological condition during the session of physical/sporting activity.

In this manner, the microcontroller 13 is capable of comparing these second data 52 with the third data 53 received previously. Moreover, the control unit 13 is capable of generating fourth data 54 for interpolation on the basis of the first data 51 measured, of the second data 52 measured and of the third data 53 memorized.

The fourth data 54 comprise, for example, a particular index called "Multiple Index of Load Area" or "MILA".

Through the data measured by the second measurement means 112 and by the third measurement means 1 13 the ventilation/oxygen consumption ratio is calculated, a value correlated with the V0₂/MET (oxygen consumption).

The oxygen consumption V0₂ is a function calculable as product of the formula (FI0_{2 *} VI) - (FE0_2*VE ), wherein "FI0₂" is the inhaled oxygen flow, "FE0₂" is the exhaled oxygen flow, "VI" is the inhalation speed and "VE" is the exhalation speed. This formula can be simplified according to the following expression Δ0₂ * V, where V is the ventilation measurement assuming the inhalation speed and the exhalation speed at the same value. This expression has a practically linear trend while the work is aerobic, i.e. before reaching the anaerobic threshold "AT".

The 6m WT physiologically obliges the patient to undergo physical stress that does not exceed the anaerobic threshold, but remains at the limit thereof. If the subject exceeds this threshold, within a few seconds he or she would be obliged to interrupt the test.

Oxygen consumption "0₂" in an idle subject at rest (seated or standing) can theoretically be expressed by the relation 3.5* weight, equivalent to one metabolic unit (MET - Metabolic Equivalent). Before reaching the anaerobic threshold "AT" the increase in V0₂ is due mainly to the increase in ventilation.

Therefore, by calculating the integral of the volume of inhaled and exhaled flow at rest and using this value as a MET (Metabolic Equivalent) in theory it is possible to learn, with good approximation, how many METs (or multiples of the integral of the reference volume at rest) the subject has used in the test and hence the V0₂, substituting the result of the previously described theoretical relation with this value.

The "MILA" index is therefore used to assess the incremental multiples of the single metabolic equivalent. This enables us to understand if the test was effectively of rectangular type, i.e. under the threshold AT, and to provide a direct result on the physical condition of the subject.

During the test, the device 1 also provides the subject with pre-recorded motivating messages (according to ERS/ATS guidelines). At the end of the six minutes required for the test, the control unit 13 emits an alarm signal 55 indicating the end of the test. This is followed by a recovery phase lasting three minutes or more in which the device 1 continues to record the data measured, but not the walking data. The end of the recovery phase is indicated by the control unit 13 through an alarm signal 55. After the test has terminated, it is possible to perform a further test on the same subject or on different subjects; in this case it may be necessary to substitute the memory medium.

The portable electromedical device 1 is therefore operatively connected to the second remote electronic processing device 22.

Through this device, it is possible to create/update a historical archive of the data related to the patient's physiological condition, on the basis of the fourth data 54 sent from the control unit 13 to the remote electronic processing device 22.

In further embodiments the data sent from the control unit 13 can also or only concern the second data 52 or the first data 51.

Operative connection of the device 1 to the remote electronic processing device 22 allows further processing of data, production of graphs and also printing of the objective results, which to date has not been possible with prior art devices.

The portable electromedical device 1, according to the present invention, automatically measures a high number of biomedical/physiological parameters during performance of a walking test, in particular a 6MWT.

However, it can also be easily used during the performance of tests of different type, such as fitness tests, tests based on running on the flat, rectangular stress tests, Cooper test and the like.

The device 1 , according to the present invention, can therefore be used in the medical field, in the sports sector or for personal use.

Due to its high level of versatility, the device 1 according to the present invention is capable of measuring, almost continuously, a large number of physical parameters and of processing the data measured, without the action of an operator, who only requires to take action in the event of an alarm signal.

The device 1 is therefore capable of providing an effective aid for performing an objective, reliable and complete assessment of the subject's performance during the test.

The electromedical device 1 has a simple and compact structure and is particularly suitable to be transported by the subject during performance of the test with high dynamics.

Due to its simple structure, the device 1 is easy to produce at industrial level, at competitive costs.

Claims

1. A portable electromedical device (1) characterized in that it comprises:

- a first measurement section (11) adapted to measure biomedical/physical parameters of a patient during a session of physical/sporting activity, said first measurement section comprising at least first means (111) for measuring the cardiac frequency of the patient, second means (112) for measuring the oxyhemoglobin saturation of the patient, third means (113) for measuring the ventilation area of the patient;

- a second measurement section (12) adapted to measure parameters related to the patient's performance during said session of physical/sporting activity, said second measurement section comprising at least fourth means (121) for measuring the distance travelled by the patient and fifth means (122) for measuring the speed maintained by the patient;

- a control unit (13), operatively connected to said first and second measurement sections so as to receive first data (51) indicative of the quantities measured by said first and second measurement section, said control unit being adapted to process, on the basis of at least said first data, at least second data (52) related to the physiological condition of the patient during said session of physical/sporting activity.

2. The portable electromedical device (1) according to claim 1, characterized in that said control unit (13) is capable of receiving third reference data (53) for said session of physical/sporting activity, said control unit (13) being adapted to process fourth data (54) of interpolation of said first data (51) and/or said second data (52) and/or said third data (53).

3. The portable electromedical device (1) according to claim 2, characterized in that said control unit (13) receives said third data (53) from a first remote electronic processing device (21) operatively connected to said control unit (13).

4. The portable electromedical device (1) according to one or more of claims 2 to 3, characterized in that said control unit (13) is capable of generating alarm signals (55) on the basis of said fourth data (54).

5. The portable electromedical device (1) according to one or more of the preceding claims, characterized in that said control unit (13) is capable of permanently memorizing said first data (51) and/or said second data (52) and/or said third data (53) and/or said fourth data (54).

6. The portable electromedical device (1) according to one or more of the preceding claims, characterized in that said control unit (13) is capable of providing in output said first data (51) and/or said second data (52) and/or said third data (53) and/or said fourth data (54).

7. The portable electromedical device (1) according to claim 6, characterized in that said control unit (13) sends said first data (51) and/or said second data (52) and/or said third data (53) and/or said fourth data (54) to a second remote electronic processing device (22) operatively connected to said control unit (13).

8. The portable electromedical device (1) according to claim 7, characterized in that said electronic processing device (22) is capable of creating/updating a historical archive of data related to the patient's physiological condition, on the basis of data sent from said control unit (13) to said remote electronic processing device (22).

9. The portable electromedical device (1) according to one or more of the preceding claims, characterized in that said control unit (13) comprises a user interface (131), accessible to the patient during said session of physical/sporting activity.

10. The portable electromedical device (1) according to claims 3 and 7, characterized in that said first and second electronic processing devices (21, 22) are included in or constituted by a single remote processing device operatively connected to said control unit (13).

1 1. The portable electromedical device (1) according to one or more of the preceding claims, characterized in that third means (113) for measuring the ventilation area of the patient comprise an oral-nasal thermocouple comprising protection means (133, 133', 133") of the measuring elements (123, 123', 123") of said oral-nasal thermocouple, said protection means (133, 133', 133") comprising a shell affixed in proximity of the ends of said measuring elements (123, 123', 123") positioned to correspond with the nostrils and mouth.