Instrumental measurement of the neuro-psycho-physical state of a person

FIELD OF THE INVENTION

The invention relates in general to instrumental systems of data acquisition, processing and evaluation for determining the neuro-psycho-physical state of a person in an entirely automatic way by means of a portable instrument. More in particular, the invention relates to portable systems for monitoring the neuro-psycho-physical condition particularly, though not exclusively, of patients affected by <i>Paralysis Agitans</i> (Parkinsonians).

BACKGROUND

The document US-A-4,199,987 (Bauers William R., et al.), discloses an electronic system for measuring time, impact energy and other athletic parameters, providing a visual display of the measured values.

The time system provides means for quantitatively measuring impact energy and reaction time to assess the training conditions of an athlete.

Parkinson's disease is a degenerative process of the central neuro system having a slow and progressive evolution. The anatomopological alteration consists in damages of neurons of dopaminergical melaninic content, located in the cerebral trunk (in the so-called black substance or <i>locus niger</i>, and in the <i>locus ceruleus</i>), with consequent reactive gliosys.

Biochemical studies have demonstrate a dysfunction of the dopaminergical nigrostriatal system (dopamine is a chemical medium by which neurons communicate among each other).

The Parkinson's disease manifests itself with: <ul id="ul0001" list-style="bullet" compact="compact"><li>rigidity (muscular hypertonicity)</li><li>acinesys</li><li>tremor.</li></ul>

<b>Rigidity</b> opposes passive stretching of muscles with a constant resistance that yields stepwise. There is a prevalence of the hypertony of the flexor muscles and this explains the general posture of the patient: head and trunk forward lining, arms in slight flexion and abduction, and at the hand level, flexion of metacarpophalangeal articulation and abduction of the thumb.

<b>Acinesy</b> is characterized by slowness and global reduction of voluntary mobility. The patient is inexpressive, amimic. There is a reduction of the pendular movements of the arms during walking and the Parkinsonian has difficulties in executing alternate movements rapidly, like drumming with fingers, making moving shadows, making flex-extensions of the first finger; handwriting tends to become small (micrography), speech tends to become hypophonic, monotonic, with sudden accelerations. Acinesy may have a unilateral beginning and predominance.

Sometimes, following an emotion, acinesy may suddenly disappear, effect that should demonstrate that the neural structures for the movements are not inhibited, but their stimulation requires exceptional excitations.

<b>Tremor</b> is present at rest. It generally disappears when executing a voluntary movement, during sleep and following a complete muscle relaxation. Emotions, stress, concentration efforts stimulate tremor. Moreover tremor of an upper limb may appear while exerting the other upper limb. Generally it is a regular tremor with a rhythm of 4-8 cycles per second, it starts at the extremity of the upper limb with alternate movements of flexal-extension of the fingers and of adduction and abduction of the thumb (similar to the gesture of counting coins).

Other symptoms are hypersalivation, hypersweeting, orthostatic hypotension, while osteotendineous reflexes are normal.

In view of the evolutive character of the disease, methods for multiparametric assessment have been developed to provide an incruent instrumental indication of the neuro-psycho-physical state of a patient.

Multiparametric measurement of reaction times of an individual, beside of aid to the diagnosis and to the monitoring of the progress of the disease in a Parkinsonian, may be useful also for establishing the state of neuro-psycho-physical health of a generally healthy person, being such a method of measurement an excellent way of discriminating alterations of reactive parameters due to other causes than a disease, such as the ingestion/assumption of alcoholics, drugs, psycho-pharmaceutical products or other substances that have an effect on the reactive and coordination capacities.

A known method of diagnostical test is the multiparametric measurement of the times of vocal reaction, described in the book: "Neurologie del comportamento (errori e correzione del controllo cerebrale)" by P. Pinelli, Ed. Ambrosiana, 1997.

The subject is instructed to provide a certain reply to a given signal: the reply may consist in pressing a push button as fast as possible. Stimulations of various types occur from time to time casually and the subject must press on a keyboard a certain key associated to the particular stimulation. In order to restrict the period of attention of the subject, an alerting signal may precede the stimulation-assignment.

The stimulation may be visual or acoustical. It may be a displayed test, an acronym, a word, a phrase. The stimulations are presented in casual succession and the subject may be called to pronounce the displayed expressions loudly, in order to implement what is referred to as <i>reading reaction.</i>

Other stimulations may be figures, of which the subject must pronounce the name, implementing what is normally called a <i>reaction to figure identification</i>.

In all these cases, every sound expressed is recorded as such through a microphone.

In all the reactions, the time intercurring between the display of the stimulation to the instant when the answer begins is defined as the <i>time of reaction</i>.

Because for the same individual every reaction time is normally slightly different from the preceding one and from the successive one in a series of reactions tests, the average and the relative standard deviation for a certain number of reactions tests to the same type of stimulation are calculated and recorded.

Typically, in order to obtain a significative average value about 10-12 reactions tests may be necessary.

Indeed, the brain functions statically and such a mode of functioning implies oscillations of the times and characters of performances.

It is therefore important to detect also the <i>duration</i> of the reply beside its correctness, both in relationship to the stimulation as well as a sequence of movements. Accuracy of the reply is also important and in case of verbal replies, even sound frequencies may be analyzed.

The utility of measuring also the duration of the reply depends from the fact that it reflects the temporal sequence of the various movements that are notably commanded through very complex neural controls.

Another method of test is described in the article: "Advances in occupational medicin and riabilitation" by F. Ceriani, A. Piazzini, R. Canger, M.P. Canevini, R. Colombo, P. Pinelli, Ed. G. Miscio.

This method rests on two tests: one of immediate reading and one of retarded reading. In the immediate reading, it is requested to pronounce the word immediately as displayed on the screen. In the retarded reading test, the patient must wait for an execution command given by a series of asterisks that appear above and below the displayed word. In a first test the reaction time is measured while in the second test the time for executing the central cerebral processing is assessed and only after the time taken by the articulation, it is requested to translate a conceptual structure in a linguistic structure highlighting all the aspects such as the grammatical coding of a message and the coding of a phonetic diagram and of a diagram of the articulation of each word.

In the last phase a phonetic diagram based on the muscle reaction and on the larynges and supra-larynges respiration and on the oromandibular system is effected. In this way the synchronization between articulation and time necessary to express the words may be verified.

A different approach of instrumental testing consists on a bioengineeristic system of acquisition and production of data on the movement of a finger, developed by Professor Alberto Rovetta.

This system is based on the following protocols: <ul id="ul0002" list-style="bullet" compact="compact"><li><i>Fast Movement:</i> from an initial reference point, the person must touch with the first finger of the hand a target as fast as possible designed to measure the impressed force while in parallel other parameters are detected among which the angular position and the velocity of the finger and the reaction time.</li><li><i>Uncontrolled movement:</i> the person must make the same movement of the preceding protocol without watching its own finger doing it but by memorizing the procedure learnt during the execution of the preceding protocol of fast movement, thus activating its Working Memory.</li><li><i>Controlled Movement:</i> in this movement, the person must control the speed of execution in such a way that by observing the target he may slow down his movement before hitting it.</li><li><i>Movement with Virtual Control:</i> implemented by having the person to follow on a graphic display the virtual imagine of his finger and at the moment in which his finger touches the real target, the virtual finger on the display changes color, thus indicating the reaching of the target and the end of the test.</li></ul>

The bioengineeristic system is composed of: <ul id="ul0003" list-style="bullet" compact="compact"><li>an exoskeleton mounted on a stand for establishing the position of the finger of the patient that must place his hand inside a glove like receptacle;</li><li>potentiometers in correspondence of the falanges of the finger for detecting their movements;</li><li>surface electrodes which through a bichannel probe provide a signal to an electromyograph;</li><li>instrumentation for measuring the force exerted on a target lamina on which strain gages are mounted.</li></ul>

The exoskeleton is supported by a common desktop PC with a ISA/EISA data acquisition card [model PC LPM 16 National Instruments] and by a software developed in Microsoft Visual C++ with development environment libraries LabWindows 2.2.1 of National Instruments, for data acquisition, analysis and constitution of a graphic interface.

A general scheme of the system is depicted in Figure 1, and Figures 2 and 3 are photographs of the exoskeleton.

A portable version of the above system, employing a portable laptop computer, using a data acquisition card PC MCIA II (Model DAQ Card-700 of National Instruments), is depicted in Figures 4 and 5.

Though implementable in a transportable form, these instrumental monitoring systems of the neuro-psycho-physical condition remain extremely burdensome and require a time consuming preparation consisting in disposing and connecting the various components.

It is a recurrently observed characteristic of reactive capabilities of an individual a remarkably high degree of subordination to the emotional state of the person.

Alike, to the case of a trivial blood pressure test, submission to a test of a neuro-psycho-physical condition may induce in a person an emotional state that markedly influences the results of the testing.

Such an influence could be greatly reduced when not completely eliminated, if the test could be completely and easily self-managed by the patient himself, without requiring any preparatory work. Moreover, a frequent execution of the test, for example daily, would make it soon emotionally insignificant thus enhancing the generation of more reliable data.

It is evident the interest and utility of a diagnostic method of the neuro-psycho-physical state of a person based on instrumentally generated data, implementable with a portable battery powered stand-alone instrument that does not require trimming or set-up operations and can be used <i>tel-quel</i> at any moment of the day and practically in any place.

These fundamental requisites are all fulfilled by the improved method and relative instrument object of the present invention.

SUMMARY OF THE INVENTION

It has been found that a multiparametric analysis of reaction times and of ergometric data in executing simple actions such as the pressing of a push button is greatly simplified and rendered far more reliable in terms of the results of the assessment, by calculating the power that is exerted in executing the action of pressing a push button, as contemplated by the test.

Measurement of the power, intended in the present context as the product of a force by a mean velocity or the product of the force by the distance covered by the moving finger in a certain time, has demonstrated itself to be strictly correlated to the command process of the brain and of the nervous system.

In case of execution of an action of relatively small duration such as the pressing of a push button, an instantaneous measurement of the exerted "power" exerted may be obtained by instrumental means and such a measure provides a good assessment of the way the brain command propagates through the neural and sensorial circuits that control the execution of the required action, implying a negligible physical effort, such as pressing a push button in a controlled manner.

In systems requiring actions to be developed in a relatively long span of time, the brain command does not appear to be determinant instant by instant during the entire execution but only in starting the action, which thereafter is performed under a complex feedback control of the movement. By contrast, execution of an action of relatively brief duration, such as the pressing of a push button through a travel distance of few millimeters as far as a mechanical stop, the ergometric data of the action and in particular the "power" exerted in substantial absence of feedback control, proves itself strongly tied to the brain command (that is to reactivity).

Analysis of the data of these tests by a Fuzzy logic microprocessor on the basis of a specific software is extremely simplified by a predetermination of the value of the exerted power in performing the action, determination that may be made by a simple logic circuitry. The calculated power value synthesizes optimally information on the speed of execution of the action and on the force exerted in performing it.

Moreover, by employing Fuzzy logic processing there is no need to preestablish thresholds fixedly and subjectively set by the doctor, allowing a less rigid consequentiality in the overall result of the assessment.

The whole monitoring system of the neuro-psycho-physical condition of a person may be contained in an object that can be easily handled with both hands or even with a single hand, having size and shape that may be similar to those of a common remote control or cellular telephone or those of a so-called joystick.

Such a miniaturization of the battery powered system in an object of extremely practical and immediate use by the patient, implies, eventually after an initial period of daily use of the instrument, a substantial disappearance of perturbed emotional states of the patient in performing the test.

The invention is as defined in claim 1.

According to this invention, the system for an instrumental monitoring of the neuro-psycho-physical condition of a person comprises: <ul id="ul0004" list-style="dash" compact="compact"><li>a push button equipped with means of detection of the initial (start) instant of the pressing, of the stopping instant of the run of the push button against a mechanical stop equipped with a dynamometer or a strain gage providing a force signal;</li><li>an amplifier of the force signal of said dynamometer or strain gage, a pass band filter and an analog/digital converter outputting a digital signal representative of the force exerted on the push button;</li><li>a logic control and processing circuit of the start and stop signals and of the force signal calculating, on the basis of the length of the travel of the push button (which normally is of few millimeters), a digital value representative of the power exerted by the finger in pressing the push button;</li><li>a Fuzzy logic microprocessor performing a multiparametric evaluation of said time and ergometric values producing an index representative of the neuro-psycho-physical condition;</li><li>a memory storing the processed data and/or said produced indexes, having interface circuits with said logic circuit and/or with said microprocessor;</li><li>a display unit, an acoustic command generating unit, a key board or equivalent interface of start-up and selection of the type of test and a powering battery.</li></ul>

The system is entirely contained in an ergonomically shaped casing that may be handled using a single hand or both hands. The casing may have the shape of a remote control or of a portable telephone or of a joystick, the latter being particularly suited to be handled with a single hand, a finger of which is used for exerting the pressing action of the push button.

In case the instrument is used for clinical purposes, for example for monitoring the progress of the disease in a Parkinsonian, the memory may record in a nonvolatile manner the data detected and elaborated during a certain number of tests, repeated at regular (e.g. daily) intervals, in a format not readable by the patient and the system may be connected to the data base of a medical center for downloading the acquired data in an appropriate coded support.

The visual interface of the instrument may be a liquid crystal display or any other alphanumeric and/or graphic display and provides an interface of communication with the person during the test, for choosing the specific test to be performed, for illustrating it to the patient and eventually for communicating the results of the tests in a quantitative or qualitative way, even by way of a number of predefined messages. Both the analysis software of the data as well as the communication messages with the patient or the person that undertakes and/or supervises the test, may be recorded in a nonvolatile manner, eventually modifiable by reprogramming the system's memory.

The acoustic interface may provide by itself or in cooperation with the display unit to the person doing the test preestablished alerting and start commands for executing the required actions.

Optionally, the system may include a sensor of movement, for example an accelerometer, for assessing the eventual presence of tremor of the hand holding the instrument of the patient or of the person subjecting himself to the test and the frequency of the eventually present tremor.

Alternatively, instead of an accelerometer, the system may optionally include a subsystem of classification of movement employing an ON/OFF sensor. The sensor detects the tremor of the hand outputting an analog signal that is converted in a digital signal and stored. The conversion may be such that the bits "1" and "0" correspond to a closed and open condition of electrical contacts. Parameters, representing the duration of the accelerations in the same direction and the number of transitions within a preestablished period of time may be fed to the Fuzzy logic processing system.

Optionally, the system of the invention may also include a block of classification of the vocal articulation generating further parameters to be fed to the Fuzzy logic processing system.

BRIEF DESCRIPTION OF THE DRAWINGS

<ul id="ul0005" list-style="none" compact="compact"><li><b>Figures 1, 2</b> and <b>3,</b> as mentioned above, illustrate a bioengineeristic system of time and ergometric data acquisition of a known type.</li><li><b>Figures 4</b> and <b>5</b> illustrate another embodiment of the known system of Figures 1, 2 and 3.</li><li><b>Figure 6</b> is a block diagram of the system of the invention.</li><li><b>Figure 7</b> is a flow chart of the data acquisition, calculation and storing of the test data.</li><li><b>Figure 8</b> shows the processing scheme implemented by the Fuzzy logic microprocessor.</li><li><b>Figure 9</b> shows a possible structure of a push button to be acted upon by the person subjected to the test.</li><li><b>Figure 10</b> shows an alternative structure of the push button.</li><li><b>Figure 11</b> is a scheme of organization of the various parts that compose the portable system of the invention.</li><li><b>Figure 12</b> depicts a possible pocketable embodiment of the portable instrument of the invention.</li><li><b>Figure 13</b> shows an alternative embodiment of the portable system of the invention.</li><li><b>Figure 14</b> shows a functional block diagram of the system of the invention equipped with a movement classifier and with a vocal articulation classifier.</li><li><b>Figure 15</b> is a functional diagram of the movement classifier of the scheme of Figure 14.</li><li><b>Figure 16</b> is a functional diagram of the classifier of vocal articulation of the scheme of Figure 14.</li><li><b>Figure 17</b> is a diagram illustrating the acoustic levels of the noise and of the signal.</li><li><b>Figure 18</b> is a flow sheet of management of the tests.</li><li><b>Figure 19</b> is a further flow sheet of the system of the invention.</li><li><b>Figure 20</b> is a scheme of the Fuzzy logic assessment.</li></ul>

DESCRIPTION OF SEVERAL EMBODIMENTS OF THE INVENTION

With reference to Figure 6, the push button 1 of the instrument is provided with suitable devices for signalling the start instant of the depression of the push button and the instant when the travel of the push button ends and for providing a signal representative of the force being exerted on the push button upon abutting against the mechanical stop. While the devices for providing the time information may be constituted by simple electrical contacts that open and close an electrical circuit, the sensor of the force exerted may be a common strain gage of a dynamometer constituting the mechanical stop against which the travel of the push button is stopped, or any functionally equivalent device.

The electrical signal provided by the strain gage or dynamometer is representative of the force being exerted and is amplified by an amplifier 2, filtered by a pass band filter 3 and converted by the analog/digital (A/D) converter 4 that provides a digital value to the input of the logic processing circuit 6, which receives, through other inputs, the time information in the form of a start instant of the pressure of the push button and of the end signal of the travel of the push button. The functional block 8 is an interface of selection of the type of test and which may be constituted by a keyboard and/or by a directional scroll switch (having a function similar to that of a "mouse").

The display unit 5 may be a liquid crystal display or an array of led indicators.

The acoustic unit 7 may be a simple transducer capable of emitting a tone (an electronic bell or chime) or an audio playback system including a loudspeaker for emitting prerecorded messages and/or commands.

A Fuzzy logic processor 10 analyzes the results of the tests generating an assessment of the neuro-psycho-physical condition as may be derived from the results of the tests on the basis of a preestablished software.

Through a communication interface 9, the system accesses a memory 11 in which are nonvolatily stored the test data and/or the results of the analysis performed by the Fuzzy logic processor.

The eventual presence of a motion sensor, typically an accelerometer 12, for providing an indication of the presence of a tremor of the hand or of the hands of the person holding the instrument is indicated in the scheme of Figure 6 by way of phantom lines. Typically the sensor 12 provides an analog signal that is converted by an A/D converter 13. The digital data representative of the frequency of an eventual tremor of the hands holding the instrument is fed to a dedicated input to the control logic circuit 6 of data handling and calculation.

Figure 7 is a flow chart of the data acquisition, calculation and storage of the test data, according to an embodiment of the invention.

As shown in the flow chart, the phase of data acquisition, calculation and storage of the test data may contemplate two types of tests, a first type called <i>virtual test,</i> in which the phases of alerting, commanding and execution of the requested action are all visualized on the display. The other type of test, named <i>quick test</i>, is entirely identical as far as the test sequence is concerned to the virtual test, but distinctly the person doing the test is prevented from visually following the various phases of the test of the on the display.

It has been found that the ability to visually follow the phases of execution of the test has the effect of expanding the reaction and execution times as compared to the same tests repeated without being able to visually follow the phases of execution, either through figures or illumination of confirmation leds.

Such an effect of expanding the times intervals is yet another parameter that is taken into consideration by the Fuzzy logic processing, the effect becoming more evident with the progress of the disease in a Parkinsonian patient.

Generally, the results of a predefined number of <i>virtual tests</i> and of a certain number of <i>quick tests</i> are accumulated in the memory. Both may be in the order of about 10 tests repeated in a relatively fast succession while recording the relative data in the memory.

Upon completing the established number of tests of one and of the other type, the Fuzzy logic processor reads and analyzes the results producing a global assessment of the neuro-psycho-physical condition.

Figure 8 describes a sample scheme of analysis of the test data by the Fuzzy logic microprocessor that generates an index of evaluation of the neuro-psycho-physical condition, so instrumentally assessed.

In the example of Figure 8, the optional detection and processing of the frequency of an eventually present tremor of the hand of the person holding the instrument is not included, but exclusively the fundamental parameters of reaction and execution times and of power exerted in performing the requested action.

Figure 9 shows a possible structure of the push button to be acted upon by the person doing the test. The start of the pressing action on the push button is detected by a respective pair of electrical contacts suitably installed in a common push button switch. Of course, the stop signal at the end of the travel of the push button may be detected by the switch itself.

The push button switch is further adapted by installing a strain gage on the mechanical stop on which the push button abuts at the end of the travel.

Considering that one of the test data used for calculating an information on the power exerted is the speed with which the push button is moved from its rest position to the stop position for a travel that may be of few millimeters (generally comprised between two millimeters and about 8-10 millimeters) it may be preferable to use a push button having a linear travel in order to obtain a more representative indication of the average speed of travel more representative for the objectives of the test.

In Figure 10 is depicted an alternative structure of the push button.

A scheme of the organization of the various parts that compose the system according to this invention is depicted in Figure 11.

In the particular example shown, the selection interface has a minimum number of four keys, respectively used for recalling the menu (MN key), for scrolling through the menu in the desired direction (arrow keys) and for confirming the selection (OK key).

The whole system is contained in a casing that can be handled with both hands or a single hand and which may have the shape and size of a common TV remote controller or pocketable telephone, as graphically depicted in Figure 12.

The possibility of being handled with a single hand is a fundamental ergonomic aspect.

An objective being that of providing an interface between the person and the instrument the most "acceptable" as possible and with a minimum emotional impact on the patient for daily monitoring his state of neuro-psycho-physical health.

An instrument that can be handled and operated with a single hand as a common remote controlled definitely reduces the psychological effect and after a certain initial period of accustomization it becomes practically null.

Another embodiment of the instrument of the invention having optimal ergonomic characteristics for being used with a single hand is depicted in Figure 13.

It corresponds more or less to the shape of the so-called joysticks used with electronic games.

With reference to the figures, upon pressing the push button three signals are generally produced: a signal of start of the pressure, a stop signal at the end of the travel of the push button and a force signal.

The microprocessor, after having commanded the issuance of an acoustic alerting signal starts a timer. After a casual delay, the processor commands the emission of the acoustic start signal of the test, attributing the value of the timer to a first variable: <i>start test tp</i>.

At the instant when the patient starts to press the push button, the relative start signal of the pressure causes the attribution of the current value of the timer to a second variable: <i>start the pressure t</i>_<i>i</i>.

The control logic then determines the interval of time <i>Δtp</i> representing the <i>reaction time:</i><maths id="math0001" num=""><math display="block"><mrow><msub><mrow><mtext mathvariant="italic">Δtp</mtext></mrow><mrow><mtext mathvariant="italic">i</mtext></mrow></msub><mtext></mtext><msub><mrow><mtext mathvariant="italic">= t</mtext></mrow><mrow><mtext mathvariant="italic">i</mtext></mrow></msub><mtext mathvariant="italic">-tp</mtext><mtext>.</mtext></mrow></math><img file="EP1598012A1_D0001.tif" /></maths>

When the run of the push button stops against the mechanical stop constituted by the strain gage, the current value of the timer is attributed to a third variable: <i>stop travel t</i>_<i>f</i>.

Being the distance travel by the push button known, the control logic calculates the interval of time for travelling it:<maths id="math0002" num=""><math display="block"><mrow><msub><mrow><mtext mathvariant="italic">Δt</mtext></mrow><mrow><mtext mathvariant="italic">if</mtext></mrow></msub><mtext> = </mtext><msub><mrow><mtext mathvariant="italic">t</mtext></mrow><mrow><mtext mathvariant="italic">f</mtext></mrow></msub><msub><mrow><mtext mathvariant="italic">-t</mtext></mrow><mrow><mtext mathvariant="italic">i</mtext></mrow></msub></mrow></math><img file="EP1598012A1_D0002.tif" /></maths>    and the average velocity of the push button:<maths id="math0003" num=""><math display="block"><mrow><msub><mrow><mtext mathvariant="italic">ν</mtext></mrow><mrow><mtext mathvariant="italic">m</mtext></mrow></msub><mtext></mtext><mtext mathvariant="italic">=</mtext><mtext></mtext><mfrac><mrow><mtext mathvariant="italic">Δx</mtext></mrow><mrow><mtext mathvariant="italic">Δt</mtext></mrow></mfrac><mtext mathvariant="italic">=</mtext><mfrac><mrow><msub><mrow><mtext mathvariant="italic">x</mtext></mrow><mrow><mtext mathvariant="italic">f</mtext></mrow></msub><msub><mrow><mtext mathvariant="italic">-x</mtext></mrow><mrow><mtext mathvariant="italic">i</mtext></mrow></msub></mrow><mrow><msub><mrow><mtext mathvariant="italic">t</mtext></mrow><mrow><mtext mathvariant="italic">f</mtext></mrow></msub><msub><mrow><mtext mathvariant="italic">-t</mtext></mrow><mrow><mtext mathvariant="italic">i</mtext></mrow></msub></mrow></mfrac><mtext></mtext><mtext mathvariant="italic">=</mtext><mtext></mtext><mfrac><mrow><mtext mathvariant="italic">corsa</mtext></mrow><mrow><msub><mrow><mtext mathvariant="italic">Δt</mtext></mrow><mrow><mtext mathvariant="italic">if</mtext></mrow></msub></mrow></mfrac></mrow></math><img file="EP1598012A1_D0003.tif" /></maths>

Upon hitting the mechanical stop, the dynamometer or the strain gage provides a measure of the force with which the push button is being pressed against the mechanical stop.

The force signal is amplified and before being converted in a digital value by the A/D converter, is filtered through a pass band filter in order to eliminate spurious readings that may be caused by eventual unbalances of the force sensor.

The force datum is multiplied by the datum representing the average velocity producing a value that has the dimensions of power.

The Fuzzy logic processor, on the basis of the specific software stored in a program memory, processes the power data together with the reaction time data for the various tests that have been performed generating an information on the neuro-psycho-physical condition in a preestablished format, which, beside being nonvolatily stored in the memory, may be displayed on the display unit, in an appropriate format that may also be preestablished by programming.

The microprocessor having acquired the data of the tests from the memory, compares the variables with a data base stored in the memory and by using a set of implications and Fuzzy logic rules according to the specific software, generates a datum of global evaluation of the neuro-psycho-physical condition.

The instrument of the invention offers the possibility of maintaining a frequent and constant monitoring of the neuro-psycho-physical condition of a patient, allowing for a quick intervention in case anomalies are detected.

The extreme simplicity of use and the possibility of adapting the analysis software of the results of the tests to specific conditions to be revealed, makes the system of the invention useful also for instrumentally verifying the state of alertness of car drivers.

The system, by suitably trimming and programming it may be perfectly suitable to detect when a person is under the effects of alcohol in alternative to the traditional blow-test and/or discriminate conditions of neuro-psycho-physical alterations due to other causes than ingestion of alcoholics, such as for example an excessive tiredness, jet-lag effects and effects that may be attributable to the assumption of drugs, and the like.

As already said above, the system of the invention may optionally include means of classification of an eventually present tremor of the hand holding the instrument, and/or of means for classifying the vocal articulation of the person subjected to the test, thus generating and providing additional parameters of evaluation to the Fuzzy logic processor, according to appropriate processing algorithms.

Figure 14 is a functional block diagram of the system of the invention equipped also with a movement classifier and with a vocal articulation classifier which are evidenced in the figure by tracing them with thicker lines.

BLOCK A (MOVEMENT CLASSIFIER)

An architecture of the sub-system of movement classification is depicted in Figure 15.

The sensor that may be and ON/OFF type accelerometer, detects the tremor of the hand and outputs an analog signal that is converted in digital signal by the A/D converter and stored. The analog signal may be converted in a digital signal in such a way that the bit "1" and "0" correspond to a closed and open condition of electrical contacts of the internal circuit of the ON/OFF sensor.

Two parameters: N_zero and N_transition are therefore generated by the processing logic circuitry of the block 6 of the scheme of Figure 14.

It is experimentally verified that there is a relation between these two parameters and the type of movement corresponding to them: <ul id="ul0006" list-style="none" compact="compact"><li>◆ if the person is calm and resting, the two parameters are both null or close to zero;</li><li>◆ the N_zero parameter represents the overall duration of acceleration phases within a certain period of time of monitoring and provides a measure of the intensity of the movement (for example when making movements ampler and ampler with the arm holding the instrument, the corresponding values of N_zero increase more and more);</li><li>◆ the N_transition parameter represents the number of transitions ON/OFF that occur within said certain period of time of monitoring; its value increases with the frequency of repeated sharp movements.</li></ul>

These two parameters are input to Fuzzy logic processing means algorithm of classification of the movement.

On the basis of experimental measurements, the values that the two parameters N_zero and N_transition may take, may for example be grouped in five Fuzzy sets, corresponding to the values <b>Very Low, Low, Medium, High</b> and <b>Very High</b>.

Similarly, the evaluation of the tremor is established according to five Fuzzy classes corresponding to <b>Very Calm, Calm, Normal, Agitated</b> and <b>Very Agitated</b>.

The Fuzzy rules are defined by considering all possible cases. In all the rules, the antecedent contains both input parameters and are contemplated all the possible combinations among the Fuzzy sets of both parameters.

The rules are of the type: <ul id="ul0007" list-style="none"><li><b>IF</b><i>N</i>_<i>zero</i><b>IS</b><i>Very Low</i><b>AND</b><i>N</i>_{<i>transition</i>}<b>IS</b><i>Very Low</i><b>THEN</b><i>tremor</i><b>IS</b><i>Very Calm</i></li><li><b>IF</b><i>N</i>_<i>zero</i><b>IS</b><i>Low</i><b>AND</b><i>N</i>_{<i>transition</i>}<b>IS</b><i>Medium</i><b>THEN</b><i>tremor</i><b>IS</b><i>Calm</i></li><li><b>IF</b><i>N</i>_<i>zero</i><b>IS</b><i>Medium</i><b>AND</b><i>N</i>_{<i>transition</i>}<b>IS</b><i>Low</i><b>THEN</b><i>tremor</i><b>IS</b><i>Normal</i></li></ul>

BLOCK B (VOICE ARTICULATION CLASSIFIER)

An architecture of the subsystem of classification of the vocal articulation block B of the scheme of Figure 14 is depicted in Figure 16.

The voice signal is acquired by a microphone, amplified, filtered and fed to an A/D converter. The logic circuitry of the block 6 of the scheme of Figure 14 calculates the parameters that are thence classified according to Fuzzy logic processing rules.

By adding this function of vocal classification, the <i>psychomotility reaction</i> of the patient following a visual stimulation is measured.

A so-called <i>immediate reading test</i> is carried out, whereby the patient must pronounce loudly a word immediately when it is visualized after a certain random delay from an alerting sound on a screen. In this way, it is not allowed any time for central cerebral processings, producing a so-called <i>read reaction.</i>

In order to restrict the period of attention of the patient, an alerting acoustic signal precedes the visual stimulation.

The delay from the displaying of the visual stimulation to the beginning instant of the vocal response of the patient, represents the <i>reaction time.</i>

It is also important to detect also the <i>duration</i> of the response, because it reflects the sequence of the various movements of vocal articulation under complex neural controls.

An example of how this optional additional system of classification may be used is as follows.

Before the push button test, a <i>test of immediate reading</i> is carried out thus detecting the reaction time and the duration of the vocal response. These parameters are determined on the basis of the acoustic signal detected by the microphone, establishing a certain threshold corresponding to the boundary between the acoustic level of the vocal signal and background noise, according to the diagram of Figure 17.

At instant <i>t0</i>, the system issues an acoustic impulse (as an alerting signal) and soon after visualizes on the display the word to be pronounced and starts a timer. After having received the acoustic stimulation, the patient, at the instant <i>t1</i> will begin to pronounce the word read from the display and will terminate to pronounce it at the instant <i>t2.</i>

The parameters that are measured are the <i>reaction time,</i> corresponding to the delay between the displaying of the word to be pronounced and the beginning of the reply from the patient, and the <i>duration of the reply,</i> that is the time the patient takes for pronouncing the word read from the display.

Therefore, the <i>time of reaction</i> and the <i>duration</i> of the reply are given by:<maths id="math0004" num=""><math display="block"><mrow><mtext mathvariant="italic">Δtr = t1 - t0</mtext></mrow></math><img file="EP1598012A1_D0004.tif" /></maths><maths id="math0005" num=""><math display="block"><mrow><mtext mathvariant="italic">Δduration = t2 - t1</mtext></mrow></math><img file="EP1598012A1_D0005.tif" /></maths>

The management of this test is done by the block 6 of the scheme of Figure 14 and may be illustrated by the flow sheet of Figure 18.

On the basis of experimental measurements, the values that the parameters: <i>reaction time (Δtr)</i> and <i>duration</i> of the reply <i>(Δduration)</i> may take, can for example be grouped in five Fuzzy sets corresponding to the values <b>Very Low, Low, Medium, High</b> and <b>Very High</b>. Similarly, the articulation of the word may be classified according to five Fuzzy classes corresponding to <b>Very Difficult, Difficult, Normal, Fast</b> and <b>Very Fast</b>.

The Fuzzy rules are defined by considering all the possible cases. In all the rules, the antecedent contains both input parameters and all the possible combinations between the Fuzzy sets of both parameters are considered.

The rules are of the following kind: <ul id="ul0008" list-style="none"><li><b>IF</b><i>Δtr</i><b>IS</b><i>Low</i><b>AND</b><i>Δduration</i><b>IS</b><i>Low</i><b>THEN</b><i>Word Articulation</i><b>IS</b><i>Difficult</i></li><li><b>IF</b><i>Δtr</i><b>IS</b><i>Medium</i><b>AND</b><i>Δduration</i><b>IS</b><i>Medium</i><b>THEN</b><i>Word Articulation</i><b>IS</b><i>Normal</i></li></ul>

According to a preferred diagnostic scheme, once this test of vocal articulation terminates, an alerting signal manifests to the patient that the test of the pressure of the push button is about to begin and in the interval of time that precedes the signal of initial pressing, the movement sensor detects the tremor of the hand, the processing logic elaborates the N_zero and N_transition storing their values in the data memory.

The managing program of the system may therefore be represented by the flow chart of Figure 19.

As far as the Fuzzy logic evaluation is concerned, this processing may follow the scheme illustrated in Figure 20.

By virtue of its "user-friendly" characteristics, the instrument of the invention is suitable even for general personal use, for example for alerting programs of particular pathologies that may imply neuro-mobility disturbances (such as for example but not exclusively the Parkinson disease).

In case of pathological conditions, the instrument of the invention may contribute to improve patient-doctor relationship by allowing the doctor to analyze objective and reliable data even in real time, or coming from several patients, without the need of frequent visits for controlling the conditions of his patients.