FI59718C - FOERFARANDE INOM LAEKARVETENSKAPEN FOER OEVERVAKNING OCH / ELLER REGISTRERING AV EN PAO EN SAENG LIGGANDE PERSONS T EX EN PATIENTS KROPPSROERELSER - Google Patents

Description

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JBT * [lBJ (11) UTLÄGGNINOSSKRIFT 5971 8 X c Patent cy innot ly 12 10 1911 '' Patent r,:. Melat ^ (51) Kv.lke / IntXI.3 A 61 B 5/0 ^ FINLAND — FINLAND (21 ) PMMttlhtkemu * - P «t * ntin * eknlng 7908 ^ 7 (22) Hakcmlipiivi - Ameknlnftdtg 13.03.79 (23) Alkupllvt —GHtlfhMsdtg 13.03 * 79 (41) Tullut Julkltak ·! - Bllvit offantilf 1U. 09 80

Patent ·) a registered. .

Patent- och regirte «tyrel ^ (44) utl.tkrlftan publlcarad 30.06.8l (32) (33) (31) Pjryduttjr acuoikaua —B« | ird prlorltat (71) Instrumentarium Oy, Elimäenkatu 22-2k, 00510 Helsinki 51, Finland -Finland (Fl) (72) Jukka Alihanka, Littoinen, Kaarle Vaahtoranta, Turku, Stig-Eyrik Björkqvist, Turku, Finland-Finland (Fl) (7U) Leitzinger Oy (5U) Method for monitoring the body movements of a person in bed, eg a patient, and and / or for registration - För-farande inom läkarvetenskapen för övervakning och / eller registre-ring av en pä en säng liggande persons, t.ex. in patients with cramps

The invention relates to a method for monitoring and / or recording body movements of a person in bed, e.g. a patient, e.g. for controlling epileptic seizures, other abnormal movements, tremors, respiration, mechanical heart function or other similar motility of the patient or subject, said change. the person is placed in a bed with antenna types connected to the amplifier and recording equipment and possibly also to the alarm equipment.

With regard to the state of the art of the invention, reference is first made to the applicant's previous FI patent publication No. 55113, in which antenna fields are used to measure the electric fields induced by the patient's bioelectrical phenomena in order to monitor the bioelectrical functions. The object of the present invention is to further develop the invention presented in the above-mentioned publication and, above all, to extend its scope to the applications mentioned at the beginning.

It is already known to register body movements caused by heartbeats, the so-called recoil movements of the heart, by ballography.

2,59718 In such a registration, the patient lies on a bed tuned to different spring systems where the recoil movement of the heart at different levels can be monitored and monitored. The method is expensive and requires well-balanced equipment and a vibration-free room. Therefore, the use of the method in clinical work has remained very limited.

Various, e.g. patient pulse monitoring systems are already known, in which special electrodes have to be connected to the patient, which usually give an false alarm when disconnected. In addition, the use of these electrodes during wakefulness causes mental stress. On the other hand, harmful error alarms have been perceived as bad in systems known to staff, even to the extent that automatic alarms are preferred to be left unattended because fault alarms disturb both care staff and patients in the ward. In addition, electrodes attached to the patient restrict patient mobility.

In order to overcome the above drawbacks and to achieve the objects of the invention, the method of the invention is mainly characterized in that antenna devices are used to detect changes in static charges caused by the movements of a person as a body movement control signal.

The bed used in the method according to the invention, in turn, is mainly characterized in that it comprises an antenna device placed under the mattress of the bed, which consists of two spaced apart antenna plates, nets, rods or the like.

The monitoring system used in connection with the bed according to the invention is mainly characterized in that the system comprises one or more beds as described above and that each bed has its own preamplifier and shielded cable connecting each antenna to the preamplifier and further comprises 5971 8 3 Filter equipment, recording and / or monitoring equipment and, if necessary, alarm equipment in a glass room or special control room.

According to the invention, there is provided a new method and apparatus, hereinafter referred to as the SCSB method and apparatus (SCSB = Static Charge Sensitive Bed). The most important applications of the invention are the registration of sleep motility, the monitoring of the patient's motility also in the waking state, for the purpose of e.g. detecting epileptic seizures, or other abnormal movement. In addition, the patient's tremor, its extent and changes in it at different times or due to the effect of the drug, for example, can be measured.

In the SCSB registration according to the invention, the breathing movement causes a slow, rippling ripple, in order to display (detect) the SCSB signal must be filtered so that the slow signal components of the order of about 0.2-3 Hz are emphasized. This can be done by filtering higher frequencies with an adjustable bandpass filter, after which the respiration variation occurs by increasing the gain. The patient's breathing can be easily monitored even for long periods of time using a slow paper speed plotter monitor. Such registration is also of diagnostic significance, e.g. for sleep apnea, the so-called Cheynne-Stokes for the detection of respiratory type associated with certain diseases.

The SCSB registration of the invention can also be used to study cardiac mechanics. In SCSB registration, the recoil motion of the heart causes an aberration very similar to the ballistic curves recorded by previous methods. SCSB ballistics does not fully correspond to any known component signal of ballistics, but is some kind of sum graph of the same phenomenon. However, the information it provides in terms of clinical significance provides a wealth of, and probably enough, information to draw conclusions about changes in cardiac mechanics. As an easy-to-use method, SCSB ballistics is likely to have clinical significance and the information provided by ballistics could be used more effectively clinically in the future. Another advantage is that the patient does not have to be moved from one place to another during registration and long and continuous monitoring could be performed.

Utilizing the SCSB ballistics according to the invention, the patient's pulse can also be monitored by filtering the signal with an adjustable bandpass filter so that the ballistic waves are highlighted by background noise, so that previously known methods for monitoring the pulse with various display devices and monitors can be used. In addition, the invention can be applied to an automatic alarm system that can be used for patient monitoring and follow-up. Pulse, respiration, movements can be monitored, e.g., during the night, without disturbing the patient.

Since the application of the invention does not require the connection of any separate electrodes to the patient, the additional mental stress associated with the monitoring situation, which has been considered a detrimental factor in prior art systems, is reduced. In the SCSB system, an alarm will occur when the ballistic heart movement stops or breathing stops. The system of the invention does not restrict patient mobility. When the patient gets out of bed, he switches off the system or this can also be done automatically so that when the patient's weight leaves the bed, the pressure switch switches off the system.

In the following, the invention will be described in more detail with reference to some application examples of the invention shown in the figures of the accompanying drawing and to various registrations obtained by means of the invention.

Figure 1 schematically shows a method and an apparatus according to the invention in a side view.

Figure 2 shows a block diagram of an implementation of a monitoring and control system according to the invention.

Figure 3 shows three different registrations, of which registration a represents an unfiltered SCSB signal registered by the method of the invention, registration b indicates respiratory movements and registration c describes a registration using ballistic triggering.

In Fig. 4, the registration a shows the registration obtained with the previously known ECG I-coupling and the registration b shows the corresponding registration obtained with the ballistics according to the invention.

Figure 5 illustrates the registration produced by eleven different movements recorded by the method according to the invention.

According to Figure 1, the patient or subject P lies on a bed 10, if there is a mattress, preferably a foam mattress 11. The patient's bedding 16 and clothing are normal. Under the mattress 11 there are two metal plates of the same size and shape or similar metal nets, rods or gratings which act as antennas. Between the metal plates 12a and 12b there is a solid wooden plate 13 which acts as an insulator between the antenna plates 12a and 12b and as a mechanical support so that the antenna plates 12a and 12b remain firmly immovable relative to each other despite the movements of the patient P. As described above, patient P and his bedding have been brought as close to the antenna as possible.

The bed 10 with its patients is placed in a space surrounded by a net 15 or the like which forms a Faradayn cage, which is not necessary. Network 15 is grounded on line 20. The metal plates 12a and 12b are connected by a shielded wire 14 to a preamplifier 17, which is e.g. a conventional differential amplifier used in EEG technology, which is characterized by a high input impedance. According to Figure 1, the differential amplifier 17 is connected to the monitoring and recording device 19 by a shielded cable 18.

Even small movements of the patient P lying in the bed 10, e.g. as close a connection as possible between the antenna and the sources represented by said charge changes. Instead of antenna plates 12a, 12b, corresponding rods can be used.

Figure 2 shows a hospital monitoring and control system applying the method and device according to the invention. This system includes a patient room 20 equipped with a Faradayn cage or similar protection as described above, which, as said, is not always necessary. In the patient room 20, beds 10a, 10b, 10c, etc. with antennas 12, as described above, are placed, the antennas of which are connected by cable to preamplifiers 17a, 17b and 17c and these in turn are protected by cables 18a, 18b, 18c to monitoring and recording devices 19. Since the patient room 20 often has to be located relatively far from the control room 27, a special electronic transmission system must be used between these rooms, which takes advantage of modulation and, for example, the principle of time division. These systems are known per se and will not be described in detail here. Figure 2 shows Line Driver 21, Multiplexer 22 and Line Reciever 23 for this system.

5971 8 6

The signals from the receiver 23 are fed to a filter 24 with a 50 Hz suction circuit and an adjustable bandpass selected to suit each application, e.g. when monitoring respiration, the band is in the range 0.2-3 Hz, in a motion sensor at night 0.5-100 Hz. After the filter 24, the signals are fed to a monitor or plotter 25, which are devices known per se. The monitor 25 can be an oscilloscope, ordinary recorders, e.g. an ECG recorder. An alarm 26 is connected to the monitor 25, which gives an alarm, e.g. in the event that the patient's breathing or heart movements cease completely or in the event that a substantial deviation from normal occurs in these movements. The alarm 26 is arranged to be triggered preferably on the basis of the amplitude of the signal, e.g. The alarm is triggered, for example, on the basis of a pulse display triggered by a ballistic wave when the pulse falls below a certain limit.

Figure 3 shows three different signals registered by the method according to the invention. Registration a is an unfiltered SCSB signal according to the invention and in Fig. B a corresponding signal passed through a low-pass or band-pass filter, e.g. a filter with a band in the range of 0.2 to 3 Hz. In this case, the ripple caused by the breathing movements is highlighted from the registration.

The principle of ballistic triggering is clear from the registration of Figure 3c. A certain voltage level L is set in connection with the registration, below which triggers are generated, etc. The number of these triggers t per unit time is e.g. a measure of the heart rate and when it falls below the set limit the alarm 26 is triggered.

Registration c in Figure 3 illustrates the ballistic trigger principle described above when applied to the method of the invention.

Figure 4 depicts the ballistics according to the invention (registration b) registered at the same time as the registration obtained by means of the previously known ECG I-coupling (registration a).

Figure 5 illustrates several registrations caused by different movements of patient P. Registration a describes a completely stationary state, in which case

Claims (1)

The periodic oscillations occurring in 7,59718 sharpening describe the oscillations produced by the patient's heart rate and respiration. Registration a ^ is registration a on a larger scale. Registration b describes registration by forefinger, c wrist movement, d ankle movement, e head movement, f patient rotation, g all finger movements, h shoulder movement, i knee movement, j isometric contraction, and k speech movement. The following are claims within the scope of which the various details of the invention may vary within the scope of the inventive idea. A method for monitoring and / or recording the body movements of a person in bed, e.g. a patient, e.g. for controlling epileptic seizures, other abnormal movements, tremors, respiration, mechanical heart function or other similar motility of the patient or subject, said person being placed in a bed (10) with antenna devices (12a, 12b) which communicate with amplifier and recording devices (17, 18, 19) and possibly also with alarm devices (26), characterized in that the antenna devices (12a, 12b) are operated on the bed (10) to detect changes in static charges caused by the movements of a person in his clothing, bedding and / or mattress (11) and that the potential differences induced by said changes in charges in the antenna devices (12a, 12b) are amplified and the electrical signal thus generated used for body movement monitoring. -naalina.