Psychophysical monitoring

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... with Elisabetta Pisano, Fabio Vergari, Alfredo D' Elia and Francesco Morandi .... Sports Medicine, University of Florence, led by Professor Giorgio Galanti and ...
Psychophysical monitoring Born some years ago in New Zealand from the mind of Brian Russell, creator and founder of Zephyr Technology, who had the insight to create a sensor that can monitor simultaneously 5 vitals parameters bases in the detection of the psychophysical behavior of the person wearing it. The parameters we are referring to are: Hearth rate, Breathing rate, Body activity, Skin temperature and Posture. The right combination of these parameters can reveal the emotional state of a person before a sudden event (underlined by palpitations or shortness of breath), or his activity, the cardiac effort, an unwell or stress being, all elements which can influence the wellbeing condition of the subject. Initially applied for “measuring” the psychophysical response of subjects in critical solutions, quickly showed its worth in many other field of application.

The measure of biomedical parameters. The sensor named Bioharness is composed of a 3D accelerometer, an infrared temperature detector, a 3electrode cardiographer reader and a respiratory rate meter . The device is inserted in a belt made of conductive fibers in which the cardiograph and breathing electrodes are integrated. The survey offers the

pos sibility of having s everal major biomedical parameters, plus ma ny others tha t a l l ows you to pl ot va rious waveforms a nd all this just by using a single non-invasive a nd l i ghtwei ght wea ra bl e devi ce.

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Fig1. The device uses a smart conductive fiber in which are inserted the breathing sensors and the cardio electrodes

The BioHarness device is “the intelligent part “ of the instrument. It is a multi parameter sensor with the function of detect, store and transmit the measured parameters in real time. It weighs about 35 gr, as it has been specifically designed to be “wearable” in a non invasive way from the patient/user during his daily activities. Its dimensions are reduced to facilitate movements and are about 80 x 40 x 15 mm. The device can store about 480 hours of activities. The battery has an operating time of about 16 hours. The data collected by the device can be transmitted to the control station through radiofrequency or Bluetooth. With regard to the frequency of the device, it is adjustable depending on the country in which they are used in accordance with applicable regulatory ISM (1)(868 - 929MHz). The first measured parameter is the heart rate and the electrocardiogram (ECG) stores the heart activity. The sensor stores the ECG value in case of rest or effort. In the first case, through the values analysis, is possible to underline coronary artery diseases, changes in heart rate (hypertrophy) and conduction of electric impulse. By the under effort ECG values it is possible to obtain a dynamic path able to underline latent heart diseases and to determine the limits of physical activity for patients with coronary failure.

Fig2 ECG

The breathing ra te gives a s pecific i nformation on the number of breathing a cts over a mi nute. In s ubstance the wearable belt integrates two piezoelectric s ensors which convert the power i n a n el ectrical signal. The s ensor i s encapsulated a nd fi xed i n the ches t s tra p l oca ted a t the l ower s ternum. The recorded signal is simply a s inusoidal wave whose ri s i ng edge corres ponds to the i ns piratory a ction while the falling edge is the expi ra tory a cti on. Zephyr’s brea thi ng detecti on a l gorithms property i s able to measure each breath. The breathing ra te detection occurs a fter a n i nterva l of a bout 30/45 s econds , requi red to i ni ti a l i ze a nd a cti va te the devi ce.

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Fig3 Breathing rate graph

The accelerometer, an integral part of BioHarness sensor, is a transducer that converts an electrical linear acceleration according to a known link. The mass contained in the accelerometer moves according to the container as a consequence of the inertial force. The entity of displacement assumed linearly related to force and to acceleration, is detected by extensometers or by the capacitive effect. Even in absence of movement, the accelerometer measures the acceleration component of 24 gravity along the measure axis. For this reason, an accelerometer, under static conditions, is able to give precise information on the posture (body inclination according to the reference axis).

Fig 4 Acceleration and Posture graph.

Fig5 Posture orientation

The Temperature measure constitutes another important parameter; the infrared sensor of the BioHarness device has a quick, careful and very precise answer.

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Fig 6; Components and functional scheme

The combination of Biomedical parameters The detected parameters can be combined between themselves to give a general and immediate estimation about the psychophysical status of the subject who is wearing the device. In the figure is shown the live monitoring in “dash” format, visible from the control display during a demonstration.

Fig 7 : first-responders

The parameters shown in the picture are the combination of hearth rate, breathing rate, posture and activity with the indication of the physiological signaling threshold beyond which the subject could be in critical situations.

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Fig 8 Combined parameters monitoring consolle

Fig 9 Multi-user simultaneous monitoring

From the foregoing you can imagine the utility and flexibility of a similar device and the benefits that could lead to a wide range of sectors.

Applications In Italy, at the beginning, this solution has been adopted by some research centers and universities for domotics and monitoring of vital parameters applications, then its validity has been noted sports to measure the values of physiological parameters of athletes, F1 pilots, football and other professional activities.

Remote monitoring Home-care : use of Zephyr Bioharness to value the degree of physical activity of an old person. The project realized at ARCES (University of Bologna) by Professor Claudio Lamberti and professor Tullio Salmon Cinotti in cooperation with Elisabetta Pisano, Fabio Vergari, Alfredo D’ Elia and Francesco Morandi tells about a Telehealth application aspect for Home-Care: form of remote assistance given at the patients home, without the need to go to hospital or ambulatory specialist . The application aimed to monitor the progression of the disease, typically in the first period after a hospital stay, to assess objectively whether and how quickly, the patient takes to reach his usual daily activities. Starting from the circumstance that the caregivers can’t and don’t want to know what ever activity the subject carries out in his own home at any given time ( e.g. walks, relax, works, exc..), it was considered interesting to develop a method that provides not so much the recognition of the specific action performed, but rather an index of increasing intensity of physical activity undertaken by the patient. The study aimed to find a technique that would allow, according to the level of activity (VMU) provided by Zephyr BioHarness, to extract a threshold value that allows to discriminate when the physical activity is part of a medium-high intensity (effort) and when the patient is involved in low intensity activities (rest) in order to estimate, during a short or long observation, an objective indication of physical activities and reached wellness status. An observation sample of 10 enrolled elderly , 5 women and 5 men, with ages between 70 and 79 years with common physical conditions and good state of health that is to say without severe hearth or motor diseases. The study was carried out at the clinic of a general practitioner. The data transmitted from the Bluetooth BioHarness device, has allowed the team to observe real time changes in physiological parameters of the patient during the exercise, verifying that they correctly fall within the prefixed observation sample, that means good hearth conditions and absence of motor problems. The activity parameters provided by the Zephyr BH expressed with VMU units ( g/sec ) were collected for each individual and properly processed. The goal of the development was to find a threshold of activity common to all subjects that may be identified automatically and objectively when the patient is doing physical activity or when it is in normal 5

rest. Starting from Zephyr activity outputs it was observed that, due to the presence of many glitch, the original signal exhibits a correct and faithful trend to the activity performed, but not quite easy to manage for the purposes of the analysis. Some digital filtering techniques have been tested, particularly a moving average low-pass filtering and a median filtering (fig 10)

Fig 10 : activities monitoring

In figure 11 a common threshold is shown for all patients. Different patients correspond to different colors. The threshold found corresponds to a value of 0.064 g, that for the moment, satisfies the purpose of the study and can be applied with sufficient reliability. The meaningful of the study was to show how, using a simple belt it is possible to remotely monitor a patient’s de-hospitalized physiological improvement and its progress towards the resumption of normal dailies activities.

Fig .11 [Activity indicator for 5 elderly and determination of the threshold to discriminate the activity level (effort /rest).

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Ambient Assisted Living. The purpose of this project studied at the Polytechnique University of Marche (Italy) is based on the determination and identification of fundamental settings of Tele Health application in a domestic environment, as for the ambient assisted living program. The proposed method consists in the definition of the different moments of the daily life of a weak and/or elderly person , on the basis of the combination of physiological and behavioral parameters, detected through environmental sensors and alarm activation detected in a scenarios procedure . Finally, the purpose and the suggested methods are essential to define the type of benefit we obtain, where • the bidirectional communication with the care giver/tutor allows the patient to be updated on the events of immediate interest and receive tips and alarms. • continuous monitoring gives a clear and complete overview of the physiological data and allow to assess the overall status of the patient, to improve the understanding of medical conditions and lifestyle of the same. The functional part of the general structure has been realized thinking to the following fundamental units: 1. “BioHarness - Zephyr” (Bluetooth) Sensor : multiparameter device, able to detect many types of information concerning vital and biomedical parameters of the elderly. 2. Environmental sensors : specific sensors located inside the domestic environment able to establish the contest where the subject lives. 3. Interpretation system ( Decision Maker): it uses Artificial Intelligence algorithms to recognize the sceneries based on the combination of the environmental, vital and statistical data. It’s able to analyze and understand the values collected in a specific moment and map them in a previously defined scenery. It generates different types of alarm linking each to a different action to be performed or provide the user with useful or necessary suggestions to communicate with near or far persons.

4. . Fig 12 Application hypothesis developed at the Polytechnique University of Marche

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The valuation of athletes physiological parameters The data collected by the instrument (especially hearth and breathing rate) allow the determination of anaerobic threshold (AT) corresponding to the transition from aerobic to anaerobic metabolism, i.e. from the consumption of fat to muscle energy, with its accumulation of lactic acid and the onset of muscle fatigue. The determination of the anaerobic threshold in athletes is essential for assessing the basis functional status and to set and monitor the training of the athlete: a program based on the continue evaluation of AT grows performances, as force and resistance, by reducing the muscle risk of joint injuries. The knowledge of AT allows a safest training for professional or older athletes, more liable to cardiac diseases or injuries. The instrument used so far for this purpose is the cardiopulmonary test (CPT), which detects breathing parameters through gas analyzers, inevitably connected to a latex face mask : nevertheless the cardiopulmonary test is and keeps to be the gold standard for the evaluation of the anaerobic threshold. The Postgraduate School of Sports Medicine, University of Florence, led by Professor Giorgio Galanti and his team with Dr Ilaria Corsani, Julius Ciullini, Vincenzo and Antonio Manzi Bovenzi has undertaken this experience. In the study both a cardiopulmonary device and the Zephyr Bioharness chest strap have been used to provide all possible information of the athlete with a wide telemetry coverage; the values concerning the anaerobic threshold (AT)obtained by a cardiopulmonary test (CPT) have been compared with the values obtained with Zephyr telemetric chest bandage. The studied sample consisted of 40 athletes (professionals and not) aged between 16 and 64 years (of which 75% < 46 years), including 4 women and 36 men. All studied subjects were healthy and without cardio-pulmonary active pathologies. Each athlete has been subjected to an incremental exercise test protocol with a treadmill or exercise bike. During testing patients used the metabolimeter mask to measure breathing tracts volumes and to telemetric Bioharness system. Results: : the values of the anaerobic threshold obtained through metabolimeter are substantially similar to those corresponding to the deflection point to the curve of heart rate (149.71±15.61 bpm vs 150.10±16.52 bpm; R=0,902; p=NS) (Fig.13), as those corresponding to the deflection point of the curve of breathing rate (149.28±22.01 bpm vs 149.71±15.61 bpm; 0,791; p=NS) (Fig.14); there was also correspondence between the heart rate matching to the deflection point in heart rate and that of the breathing rate (149.28 ±22.01 bpm vs 150.10±16.52 bpm; R=0,837; p=NS) (Fig.15).The data obtained in test repeated after 24 hours were comparable to those obtained during the first test (HR atrest=74,83±10.68 bpm vs 74.33±10.76 bpm; p=NS; AT=152.50±7.53 bpm vs 152.67 ±6.86 bpm; p=NS; HR max=170.00±3.95 bpm vs 170.33±3.83 bpm; p=NS). BioHarness telemetry system presented himself as a reliable and suitable tool for the telemetry functional evaluation of the athlete and for monitoring the time of his anaerobic threshold. It overcomes the difficulties that the CPT has in claustrophobics subjects, or in patients with lactic allergies or adverse reactions to disinfectants or material in use. It also shows a significant improvement in cost and time compared to the CPT (its management requires the exclusive use in a laboratory, with the dedicated doctors. However, the cardiopulmonary exercise testing remains the gold standard for the functional evaluation of the athlete, but after a first evaluation statement with the metabolimeter, the athlete may be monitored frequently and without creating further 8

hardships through Bioharness. The data accuracy, and ease of use allows this instrument to be used in many racing circles. In conclusion, the Zephyr BioHarness has shown its validity for the functional evaluation of the athlete in the acquisition of reliable data, with the versatility and ease of use that allow a wider spread in sports medicine for the benefit of professionals and not.

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Fig 13. Overlap between AT measured with CPT method (Metabolimeter,Mtb) and HR curve

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Fig14.Overlap of AT measure with CPT (Metabolimeter, Mtb) and breathing curve BR 180

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Fig.15. Scatter plot on the overlap of the anaerobic threshold obtained from the curve deflection points of heart rate and respiratory rate.

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Fig.16. Heart rate trend at AT

Fig. 17. Breathing rate at AT

Fig 18 Athletes during the fase of the CPT test. At the same time they wear BioHarness chest strap, masks it measures gas and ECG.

Fig 19 Bioharness Software .The combination of heart rate, breathing rate and activities data allow to collect HR, BR, HRR , VO2MAX and AT immediately.

F1 pilots Experiences have been developed in other sports where the psychophysical aspect is more important than the muscle form. This is the case of the Formula 1racing teams, where recently the Bioharness chest strap 10

has been introduced to connect the physical activity with the heart and breathing rate and observe in detail the condition of stress of pilots during the F1 races. The results are still under development but they promise to be very interesting.

Fig 20 Testing ground during F1 tests . The physiological data are collected and transmitted in real time to the control central.

Fig 21Data received in real time by pilots while they run at 300Km/h on the test track.

Psychophysical monitoring during extreme driving training course Among the innovative applications we consider of great importance, we show the results of an exercise done in cooperation with a known Italian organization. We speak about the valuation of the psychophysical behavior of drivers during an extreme driving course when a danger obstacle suddenly appears. The tests have been realized during a test of “Secure driving”. It’s known that often car accidents happen for several reasons including the driver's inexperience in dealing with a sudden event that causes most of the time the loss of control of the vehicle. It is also known that the probability of such an event is inversely proportional to the level of self-control of the driver. Our experience has focused precisely on the latter factor: measuring the degree of emotion shown in candidates for safe driving course in the most critical moments to demonstrate that the acquisition of driving skills also needs a good dose of self-control. The graph in Fig 22 shows the cardiopulmonary trend of three subjects dealing with the same obstacle: 1) An trainer with proven experience (blue curve ) 2) A student which has performed 3 or 4 tests ( brown curve) 3) A student at the first test (red curve) 11

As expected the results show that, that the emotionality degree is inversely proportional to the experience, in fact, the trainer shows absolutely no emotion while the car running at 120 km /h in a twisting maelstrom of spin, the second student is already showing a first determination of self-control and the third is definitely scared.

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Fig 22 : cardiopulmonary trend during secure driving tests.

Conclusion Prevention and individual wellness is subject to different combinations of the basic biophysical parameters that can be influenced by several factors. The combined monitoring of these parameters must be an integral part of the concept of telemedicine, so that it is efficient and functional. As demonstrated by the different applications described, the knowledge of a single parameter such as heart or breathing rate, blood pressure, etc. are essential to highlight individual diseases or sufferings but are not able to "measure" the psychophysical effect as we have seen , which contribute to outline a detailed profile of the subject, his wellness, his physical resilience, his sporting potential and self-control.

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