JP7734009B2 - Patient monitor - Google Patents

Description

The present invention relates to a biological information monitor that receives biological information transmitted wirelessly, such as a central monitor.

Conventionally, central monitors installed in nurse stations at medical institutions have been known as vital sign monitors for monitoring the conditions of multiple patients. Central monitors receive vital sign information (e.g., electrocardiograms, blood pressure, arterial oxygen saturation, etc.) from bedside monitors installed at the bedside of each patient in an intensive care unit, hospital room, etc., and display it on a screen (see, for example, Patent Document 1). Central monitors can also receive and display vital sign information wirelessly transmitted from telemeter transmitters worn by patients.

Japanese Patent Application Laid-Open No. 2005-124903

However, in order for the central monitor to collect and display wirelessly transmitted vital signs, it goes without saying that the central monitor must be able to correctly demodulate the wirelessly transmitted vital signs.

Generally, wireless communication between bedside monitors and telemetry transmitters (hereinafter referred to as "biometric information acquisition terminals") within a hospital and the central monitor is carried out via antennas installed on the central monitor or in the ceiling of the hallway, etc. Depending on the location of the biometric information acquisition terminal and the wireless propagation environment, the central monitor may not be able to correctly demodulate the biometric information. For example, if the biometric information acquisition terminal is located far from the antenna, or if there is an obstacle between the antenna and the biometric information acquisition terminal that blocks radio waves, or if noise interference occurs, the central monitor may not be able to demodulate the biometric information.

The wireless propagation environment changes constantly due to factors such as the location of the biometric information acquisition terminal, malfunctions, antenna deterioration, and external noise. As a result, the reception quality of the biometric information at the central monitor may deteriorate, and if monitoring is continued without noticing this, it may become impossible to demodulate the biometric information.

A situation in which the central monitor is unable to obtain vital signs during vital signs monitoring is something that must be avoided at all costs from a medical perspective.

The present invention was made in consideration of the above points and provides a biological information monitor that can avoid situations where biological information cannot be acquired during monitoring due to deterioration of reception quality.

One aspect of the biological information monitor of the present invention is
a demodulation unit capable of demodulating biometric information wirelessly transmitted from a plurality of biometric information acquisition terminals;
a field strength measuring unit for measuring the field strength of a medical telemetry band including at least all frequency bands demodulated by the demodulation unit;
an S/N ratio acquisition unit that acquires an S/N ratio by taking the field strength of a frequency demodulated by the demodulation unit among the frequencies measured by the field strength measurement unit as the field strength of a desired wave and the field strength of a frequency excluding at least the frequency demodulated by the demodulation unit as the field strength of noise;
an alarm output unit that outputs an alarm based on the S/N ratio obtained by the S/N ratio acquisition unit;
Equipped with.

This invention makes it possible to realize a biological information monitor that can avoid situations in which biological information cannot be acquired during monitoring due to deterioration in reception quality.

FIG. 1 is a diagram showing a schematic configuration of a biological information monitoring system to which a central monitor according to an embodiment is applied. FIG. 1 is a block diagram showing a configuration of a main part of a central monitor according to an embodiment of the present invention; Block diagram showing the configuration of the receiving unit Figure showing an example of biological information displayed on a central monitor Figure showing an example of the field strength display screen on the central monitor 1 is a flowchart illustrating a monitoring channel quality warning operation according to an embodiment.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows the schematic configuration of a biological information monitoring system to which the central monitor of this embodiment is applied. The biological information monitoring system 10 in Figure 1 is installed, for example, in a hospital.

A central monitor 100 is installed in the nurse's station, and the central monitor 100 receives each patient's biometric information wirelessly transmitted from biometric information acquisition terminals such as bedside monitors 20 (20-1 to 20-n) or telemeter transmitters 30-1 to 30-m via antennas AN1, AN2-1, AN2-2, and AN2-3.

Antennas AN1, AN2-1, AN2-2, and AN2-3 are attached directly to the central monitor 100 or connected to the central monitor 100 via cables. Specifically, antenna AN1 is attached directly to the central monitor 100, and antennas AN2 (AN2-1 to AN2-3) are connected to the central monitor 100 via cables 400. Antenna AN2 is installed, for example, in the ceiling of a hospital corridor.

The configuration of antenna AN2 may be either an antenna system or a leaky coaxial cable system. The antenna system uses a whip antenna or similar as an antenna, and antennas AN2-1 to AN2-3 are connected by wire. The leaky coaxial cable system uses leaky coaxial cables as antennas AN2-1 to AN2-3. Antennas AN1 and AN2 may be of any system that complies with the specified low-power radio standard. Furthermore, the number of antennas is not limited to the example shown in Figure 1.

In practice, biological information wirelessly transmitted from the bedside monitor 20 and telemeter transmitter 30 (i.e., the biological information acquisition terminal) is first received by antenna AN1 or AN2. In the example of Figure 1, biological information transmitted from telemeter transmitter 30-m is received by antenna AN1, and biological information transmitted from bedside monitors 20-1, 20-n and telemeter transmitter 30-1 is received by wired antenna AN2.

In this way, biological information wirelessly transmitted from medical terminals such as the bedside monitor 20 and telemeter transmitter 30 is received and collected by the central monitor 100 and displayed on the central monitor 100.

Figure 2 is a block diagram showing the main components of the central monitor 100 according to this embodiment.

The central monitor 100 inputs signals received by antennas AN1 and AN2 to the receiver 200. The receiver 200 demodulates the modulated biological information by performing predetermined wireless processing on the input signals. The receiver 200 also has the function of measuring the field strength of radio waves in the medical telemetry frequency band (420 MHz to 450 MHz). The detailed configuration of the receiver 200 will be described later.

Here, we'll briefly explain the frequency bands used in medical telemetry. According to the "Operational Guidelines for Low-Power Medical Telemetry" established by the Japan Electronics and Information Technology Industries Association (JEITA), 420 to 450 MHz is specified as the frequency band used by medical telemetry. Furthermore, six frequency bands (which can also be called bands) 1 to 6 are allocated within the 420 to 450 MHz range. Each of frequency bands 1 to 6 can be assigned 40, 80, or 120 channels (which can also be called "floors" or "biometric information acquisition terminals"). Incidentally, the spacing between each channel is 12.5 kHz.

The biometric information demodulated by the receiving unit 101 is input to the biometric information analysis unit 110. The biometric information analysis unit 110 creates a biometric information waveform from the biometric information and calculates maximum, minimum, and average values, etc.

The output of the biological information analysis unit 110 is input to the display control unit 120 and the alarm control unit 130. The display control unit 120 switches the display based on an operation signal from the operation unit 180. The display control unit 120 displays biological information such as an electrocardiogram, SpO2, and blood pressure on the display unit 140. Furthermore, when the display control unit 120 receives an alarm output instruction signal from the alarm control unit 130, it displays an alarm on the display unit 140. The alarm output instruction signal from the alarm control unit 130 is also input to an alarm indicator 150, which consists of an LED (Light Emitting Diode), a speaker, etc., and the alarm is output as light or sound.

Meanwhile, information on the electric field strength of the radio waves measured by the receiving unit 200 is output to the display control unit 120. Here, the electric field strength information is, for example, information that represents the electric field strength in the form of a two-dimensional graph with frequency on the horizontal axis and power (or voltage) on the vertical axis. This two-dimensional graph is displayed on the display unit 140 by the display control unit 120.

The central monitor 100 also has a control unit 170, an operation unit 180, and a barcode reader 190. The control unit 170 assigns and links carrier frequencies to each biometric information acquisition terminal based on biometric information acquisition terminal identification information input from the operation unit 180 or barcode reader 190, and outputs frequency assignment information to the receiving unit 200.

In addition to this configuration, the central monitor 100 has an S/N ratio acquisition unit 401 and an alarm output unit 402.

The S/N ratio acquisition unit 401 acquires the S/N ratio by taking the field strength of the frequency demodulated by the demodulation unit 240, among the frequencies measured by the field strength measurement unit 250, as the field strength of the desired wave (monitoring channel), and by taking the field strength of the frequencies other than the frequency demodulated by the demodulation unit 240 as the field strength of noise (non-monitoring channel).

The S/N acquisition unit 401 of this embodiment has a monitoring channel field strength calculation unit 401a, a non-monitoring channel field strength calculation unit 401b, and an S/N ratio calculation unit 401c. Here, the monitoring channel refers to the channel that receives biological information (or demodulates the biological information).

The monitoring channel field strength calculation unit 401a calculates the field strength of the frequency demodulated by the demodulation unit 240 (Figure 3) from among the frequencies measured by the field strength measurement unit 250 (Figure 3) as the field strength of the desired wave.

The non-monitoring channel field strength calculation unit 401b calculates the field strength of frequencies excluding at least the frequencies demodulated by the demodulation unit 240 (Figure 3) as the field strength of noise.

The S/N ratio calculation unit 401c calculates the S/N ratio (Signal-to-Noise Ratio) by subtracting the received field strength of noise obtained by the non-monitoring channel field strength calculation unit 401b from the field strength of the desired signal obtained by the monitoring channel field strength calculation unit 401a.

The received field strength calculated by the monitoring channel field strength calculation unit 401a and the non-monitoring channel field strength calculation unit 401b may be power, a voltage value, a current value, etc.

The alarm output unit 402 outputs an alarm based on the S/N ratio obtained by the S/N ratio acquisition unit 401. Specifically, the alarm output unit 402 outputs an alarm when the S/N ratio falls below a predetermined threshold. The alarm output unit 402 is configured, for example, with an LED (Light Emitting Diode) or a speaker, and notifies the user by light or sound that the S/N ratio has fallen below the predetermined threshold. The alarm output unit 402 may also output an alarm using, for example, the display unit 140 or the alarm indicator 150.

The functions of the S/N ratio acquisition unit 401 and the alarm output unit 402 can be realized by a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The CPU reads a program corresponding to the processing content from the ROM, loads it into the RAM, and works with the loaded program to centrally control the operation of each element. In this embodiment, the S/N ratio acquisition unit 401 and the alarm output unit 402 are controlled by the control unit 170.

Figure 3 is a block diagram showing the configuration of the receiving unit 200.

The receiving unit 200 inputs the signals received by each antenna AN1 and AN2 to the distributor 230 via a bandpass filter (BPF) 210 and an amplifier (AMP) 220.

The distributor 230 outputs the input received signal to the demodulator 240 and the field strength measurement unit 250. Here, the distributor 230 may, for example, select either the signal from antenna AN1 or antenna AN2 and output it to the demodulator 240 and the field strength measurement unit 250, or may combine the signals from antennas AN1 and AN2 and output them to the demodulator 240 and the field strength measurement unit 250.

The distribution of the distributor 230 is controlled, for example, by the user operating the operation unit 180. As a result, for example, if the user wants to know the field strength based on the signal received by antenna AN1, the distributor 230 outputs the signal received by antenna AN1 to the field strength measurement unit 250.

The distributor 230 may also select which received signal from antenna A1 or AN2 to distribute to each of the demodulation circuits 1 to 12 included in the demodulation unit 240. For example, if the telemeter transmitter 30-1 in Figure 1 is assigned to demodulation circuit 1, the signal from telemeter transmitter 30-1 should be stronger at antenna AN2 than at antenna AN1, so the distributor 230 should distribute the received signal from antenna AN2 to demodulation circuit 1.

The demodulation unit 240 has demodulation circuits (which may also be called "receiving modules") equal to the number of beds (which may also be called the "number of channels" or "number of biometric information acquisition terminals"). In the example of Figure 3, it has demodulation circuits 1 to 12 for 12 beds. Specifically, each demodulation circuit 1 to 12 demodulates the biometric information by multiplying the input signal by a different carrier frequency. For example, demodulation circuit 1 multiplies by carrier frequency 1, demodulation circuit 2 multiplies by carrier frequency 2, ... and demodulation circuit 12 multiplies by carrier frequency 12.

The biometric information of each bed (each biometric information acquisition terminal) demodulated by the demodulation unit 240 is converted by the conversion circuit 270 into data suitable for analysis by the biometric information analysis unit 110 (Figure 2).

In addition to this configuration, the receiving unit 200 of the central monitor 100 of this embodiment has a field strength measuring unit 250 in addition to the demodulating unit 240 that demodulates the biological information. The field strength measuring unit 250 measures the field strength of the medical telemetry band, which includes at least all of the demodulation frequency bands demodulated by the demodulating unit 240.

In this embodiment, the field strength measurement unit 250 measures the field strength in the medical telemetry band using a sweep method. Field strength measurement using the sweep method is a known technique, so it will only be briefly described here. The field strength measurement unit 250 converts the input signal to IF (intermediate frequency) using a mixer and local oscillator. At this time, the conversion to IF is performed while automatically sweeping the frequency of the local oscillator, and the power value that has passed through a narrowband IF filter is output as field strength information. Note that the field strength measurement unit 250 may measure field strength information using the FFT method instead of the sweep method.

By measuring and displaying the field strength of radio waves in the medical telemetry band using the field strength measurement unit 250, the user can understand the radio wave environment of the channel to which the biometric information acquisition terminal is assigned.

The operation of distributor 230, demodulator 240, and field strength measurement unit 250 is controlled by wireless control unit 260. For example, wireless control unit 260 controls which of demodulator circuits 1 to 12 to operate based on frequency allocation information from control unit 170. For example, if carrier frequency 1 is assigned to bedside monitor 20-1, carrier frequency 2 is assigned to bedside monitor 20-n, carrier frequency 7 is assigned to telemeter transmitter 30-1, and carrier frequency 9 is assigned to telemeter transmitter 30-m, demodulator circuits 1, 2, 7, and 9 will be operated.

In addition, the wireless control unit 260 assigns floors (which may also be called "channels" or "biometric information acquisition terminals") to each demodulation circuit 1-12 by setting carrier frequencies 1-12 for each demodulation circuit 1-12.

Figure 4 shows an example of biological information displayed on the display unit 140 of the central monitor 100. Note that in the example of Figure 4, biological information for eight beds is displayed, but with the configuration of Figure 3 described above, biological information for up to 12 beds can be displayed via wireless reception.

Figure 5 shows an example of a received field strength display image displayed on the display unit 140 of the central monitor 100.

In the example of Figure 5, a field strength measurement selection area AR1, a field strength graph area AR2, a band selection area AR3, an antenna selection area AR4, and a scan start position adjustment area AR5 are displayed. In this embodiment, the display unit 140 has a touch panel configuration, and operation signals corresponding to touch operations by the user are input to the control unit 170, and various controls are changed in response to the operation signals.

The reception strength measurement selection area AR1 displays a "Spectrum analyzer only" button. When the "Spectrum analyzer only" button is touched, the field strength measurement unit 250 measures the field strength. In addition, the reception strength measurement selection area AR1 displays buttons RF-01 to RF-12. These buttons correspond to demodulation circuits 1 to 12; for example, when the RF-01 button is touched, the field strength is measured by demodulation circuit 1, and when the RF-02 button is touched, the field strength is measured by demodulation circuit 2.

In other words, demodulation circuits 1-12 not only have the function of demodulating biological information, but also have the function of measuring the field strength of the medical telemeter band, similar to the field strength measurement unit 250. In other words, because demodulation of biological information requires components similar to the field strength measurement unit 250, such as a mixer and local oscillator, demodulation circuits 1-12 are also able to measure field strength using these components. However, since this embodiment does not demodulate biological information but has a field strength measurement unit 250 dedicated to field strength measurement, it is possible to measure the radio wave conditions in the medical telemeter frequency band regardless of the status of biological information monitoring.

The field strength graph area AR2 displays the field strength of each channel. In the example shown, of the six bands that make up the medical telemetry band (1000s, 2000s, 3000s, 4000s, 5000s, and 6000s), the field strength of the 2000s band is displayed. The user can determine which band's field strength to measure and display by selecting the desired band in the band selection area AR3. In the example shown, the field strength of 120 channels is displayed for each band.

The user can select the antenna for which the field strength will be measured by touching the antenna selection area AR4. For example, touching the "Antenna 1" button will measure and display the field strength of the signal received by antenna AN1, and touching the "Antenna 2" button will measure and display the field strength of the signal received by antenna AN2. Incidentally, instead of selecting just one antenna, it is also possible to select all two or more antennas and measure and display the field strength of their combined received signal.

By touching the scan start position adjustment area AR5, the user can adjust the scan start position where field strength is measured and displayed. Scanning the field strength of all channels within a band can take several tens of seconds, depending on the device's performance. Therefore, if the scan is simply started from the channel with the lowest frequency and the channel of interest is a high-frequency channel, the user will have to wait a long time to find out the field strength around that channel.

The user can avoid this inconvenience by touching the scan start position adjustment area AR5. For example, if the channel of interest is channel 2115, the user touches the "110" button in the scan start position adjustment area AR5. As a result, field strength measurements and display scans are performed starting from channel 2110, allowing the user to quickly find out the field strength around the channel of interest, channel 2115.

Figure 6 is a flowchart illustrating the monitoring channel quality warning operation performed by the S/N ratio acquisition unit 401 and the warning output unit 402 according to this embodiment.

First, in step S1, the control unit 170 sets a monitoring channel i and a non-monitoring channel j. In this embodiment, the monitoring channel i is set to 1, 2, 7, or 9, and the non-monitoring channels are set to channels in the medical telemetry band other than the monitoring channel. More preferably, the non-monitoring channels are set to channels in the medical telemetry band other than the monitoring channel and its adjacent channels.

In the following step S2, the non-monitoring channel field strength calculation unit 401b calculates the average field strength E2 of the non-monitoring channels. Note that in this embodiment, the average field strength of the non-monitoring channel j is calculated, but the field strength of one of the one or more non-monitoring channels j may be calculated as a representative value. However, calculating the average improves the reliability of the estimated noise.

In the following step S3, the monitoring channel field strength calculation unit 401a calculates the field strength E1 of the kth monitoring channel. In this embodiment, the first monitoring channel is channel 1, the second monitoring channel is channel 2, the third monitoring channel is channel 7, and the fourth monitoring channel is channel 9. Therefore, in step S3, the field strength E1 of the first monitoring channel 1 is first calculated.

In the following step S4, the S/N ratio calculation unit 401c determines whether the S/N ratio (i.e., E1/E2) is less than a predetermined threshold value Th0. If it is less than the threshold value Th0 (step S4; YES), the process proceeds to step S5, where the alarm output unit 402 outputs an alarm. This alarm notifies the user that the quality of monitoring channel 1 has deteriorated.

In practice, to achieve stable wireless monitoring of biological information, it is necessary to maintain an appropriate S/N ratio for the electric field strength. Generally, an S/N ratio of 30 dB or higher is required. Therefore, the threshold value Th0 is set to, for example, 30 dB.

In the following step S6, it is determined whether the S/N ratio determination for all monitoring channels i has been completed. If not, the process returns to step S3. When returning to step S3, the field strength E1 of the second monitoring channel 2 is calculated, and then step S4 is performed. In this way, the S/N ratio is calculated individually for all monitoring channels i = 1, 2, 7, 9, and a determination is made as to whether an alarm is required.

As a result, users (nurses, ME technicians, etc.) can know whether there are any monitoring channels with poor reception quality.

As described above, according to this embodiment, the central monitor 100 includes a demodulator 240 capable of demodulating biological information wirelessly transmitted from multiple biological information acquisition terminals (bedside monitor 20, telemeter transmitter 30); a field strength measurement unit 250 that measures the field strength of the medical telemeter band, which includes at least all frequency bands demodulated by the demodulator 240; an S/N ratio acquisition unit 401 that acquires the S/N ratio by defining the field strength of the frequency demodulated by the demodulator 240 among the frequencies measured by the field strength measurement unit 250 as the field strength of the desired wave and the field strength of the frequency excluding at least the frequency demodulated by the demodulator 240 as the field strength of the noise; and an alarm output unit 402 that outputs an alarm based on the S/N ratio acquired by the S/N ratio acquisition unit 401.

This allows the user (nurse, medical engineer, etc.) to be notified if there is a channel with poor reception quality among the channels being monitored, and encourages the user to inspect (and in some cases replace) the equipment with poor reception quality. As a result, the user can quickly become aware of reception-related problems caused by malfunctions in the wireless transmitter, deterioration of the antenna equipment, external noise, etc., and can prevent poor reception during monitoring.

This makes it possible to realize a biological information monitor that can avoid situations where biological information cannot be obtained during monitoring due to poor radio wave conditions.

Incidentally, in a biological information monitoring system, biological information such as electrocardiograms sent from the biological information acquisition terminal to the central monitor must be displayed and recorded on the central monitor without interruption. With this in mind, this embodiment employs a method for acquiring the S/N ratio of the monitoring channel without inserting a known signal into the monitoring channel. In other words, the S/N ratio of the monitoring channel is calculated based on the idea that the received field strength of non-monitoring channels is equivalent to the noise components that are also superimposed on the monitoring channel. In this way, it is possible to notify the user of a deterioration in the quality of the channel currently being monitored, without interrupting the biological information being monitored by the central monitor.

The above-described embodiments are merely examples of specific ways of implementing the present invention, and should not be construed as limiting the technical scope of the present invention. In other words, the present invention can be implemented in various forms without departing from its gist or main characteristics.

In the above embodiment, we have described a case where the S/N ratio is calculated based on the electric field strength obtained by the electric field strength measurement unit 250, but it is also possible to measure the electric field strength using the demodulation unit 240 and calculate the S/N ratio based on that electric field strength.

In the above embodiment, the present invention has been described as being applied to a central monitor, but it is not limited to this. In essence, it can be widely applied to any biological information monitor that demodulates and displays multiple pieces of biological information wirelessly transmitted from multiple biological information acquisition terminals.

The present invention has the effect of preventing situations in which biological information cannot be acquired during monitoring due to deterioration of reception quality, and is suitable for central monitors, for example.

10 Biological information monitoring system 20 (20-1 to 20-n) Bedside monitor 30 (30-1 to 30-m) Telemeter transmitter 100 Central monitor 110 Biological information analysis unit 120 Display control unit 130 Alarm control unit 140 Display unit 150 Alarm indicator 170 Control unit 180 Operation unit 190 Barcode reader 200 Receiving unit 210 Bandpass filter (BPF)
220 Amplifier (AMP)
230 Distributor 240 Demodulation section 250 Field strength measurement section 260 Radio control section 270 Conversion circuit 401 S/N ratio acquisition section 401a Monitoring channel field strength calculation section 401b Non-monitoring channel field strength calculation section 401c S/N ratio calculation section 402 Alarm output section AN1, AN2-1, AN2-2, AN2-3 Antennas AR1 Field strength measurement selection area AR2 Field strength graph area AR3 Band selection area AR4 Antenna selection area AR5 Scan start position adjustment area

Claims (5)

a demodulation unit capable of demodulating biometric information wirelessly transmitted from a plurality of biometric information acquisition terminals;
a field strength measuring unit for measuring the field strength of a medical telemetry band including at least all frequency bands demodulated by the demodulation unit;
an S/N ratio acquisition unit that acquires an S/N ratio by taking the field strength of a frequency demodulated by the demodulation unit among the frequencies measured by the field strength measurement unit as the field strength of a desired wave and the field strength of a frequency excluding at least the frequency demodulated by the demodulation unit as the field strength of noise;
an alarm output unit that outputs an alarm based on the S/N ratio obtained by the S/N ratio acquisition unit;
Equipped with
The electric field intensity of the noise is an electric field intensity excluding an electric field intensity of a frequency adjacent to the frequency being demodulated by the demodulation unit.
Vital sign monitor. The S/N ratio acquisition unit
a first electric field strength calculation unit that calculates the electric field strength of a frequency demodulated by the demodulation unit from among the frequencies measured by the electric field strength measurement unit as the electric field strength of a desired wave;
a second electric field strength calculation unit that calculates, as the electric field strength of the noise, the electric field strength of a frequency other than at least the frequency demodulated by the demodulation unit;
an S/N ratio calculation unit that calculates an S/N ratio by subtracting the field strength of the desired wave from the field strength of the noise;
Equipped with
The biological information monitor according to claim 1 . When there are a plurality of channels receiving the biological information,
the S/N ratio acquisition unit acquires S/N ratios of a plurality of channels receiving the biological information,
the alarm output unit controls an alarm output for each channel based on an S/N ratio of each of the plurality of channels receiving the biological information.
The biological information monitor according to claim 1 or 2. a display unit that displays the biological information,
The display unit displays the alarm output from the alarm output unit.
The biological information monitor according to any one of claims 1 to 3. a display unit that displays the biological information,
the display unit displays a field strength display area for displaying the field strength of the frequency being measured by the field strength measurement unit, and a start position adjustment area for selecting a measurement start position in the frequency band for measuring the field strength,
the electric field strength measurement unit measures the electric field strength based on the measurement start position.
The biological information monitor according to any one of claims 1 to 4.