Medical probe buffer for buffering measured physiological signals

Abstract

The present invention relates to a medical probe buffer for buffering measured physiological signals in the human body, comprising: at least one receiving port connectable to a receiving line arranged to transmit signals based on physiological signals of the human body; each receiving port having an associated receiving buffer arranged to buffer signals from each receiving port, wherein each receiving buffer comprises a receiving port having inputs and outputs, and an associated receiving resistor conductively disposed between each receiving port and the input of each receiving buffer; at least one transmitting port connectable to a transmitting line arranged to transmit signals to the human body; and an associated transmitting buffer arranged to buffer signals supplied to each transmitting port, wherein each transmitting buffer comprises a transmitting port having inputs and outputs, and an associated transmitting resistor conductively disposed between the output of the transmitting buffer and the transmitting port, wherein the resistor group is formed by receiving resistors and transmitting resistors, and the resistance values ​​of the resistors in the resistor group are pre-selected so that when an electrical short-circuit failure occurs in the resistors in the resistor group, the current flowing through the human body does not exceed a safety threshold current.

Description

Detailed Description of the Invention

[0001] [Field of the Invention] The present invention relates to a medical probe buffer for buffering measured physiological signals in the human body. The present invention further relates to a medical probe and a medical device incorporating the medical probe buffer. [Background of the Invention] A subset of medical electrical equipment measures one or more physiological signals of the human body using electrical signals. This subset of medical electrical equipment should comply with the safety requirements defined in the IEC60601 standard, more specifically the IEC60601-1 standard, and even more specifically the latest version of the IEC60601-1 Edition 3.1 standard, while measuring the physiological signals.

[0002] One of the requirements in the IEC60601-1 standard is that the medical electrical equipment be resistant and / or safe when one or more faults, such as a short circuit, occur in the electrical components of the medical electrical equipment. A common solution is to arrange one or more resistors in series on each wire. The resistor should have a sufficiently high resistance to limit the current flowing through the human body where the physiological signal is measured to less than the safety threshold current defined in the IEC60601-1 standard. Three series resistors may be preselected to balance reducing the resistance value and suppressing the number of additional electrical components.

[0003] Since the resistance values of the series resistors are usually very high, these three series resistors significantly attenuate the electrical signal in their line. Further, each of the three series resistors is a noise source that reduces the signal-to-noise ratio (SNR) of the electrical signal in its line. Each of the significant attenuation of the electrical signal and the reduction of the SNR, either alone or in combination, surely hinders the accurate measurement of the physiological signal when complying with the IEC60601-1 standard. [Summary of the Invention] The object of the present invention is to overcome one or more of the above-mentioned drawbacks. According to a first aspect of the present invention, a medical probe buffer for buffering measured physiological signals in the human body comprises, each receiving port having at least one receiving port connectable to a receiving line arranged to transmit signals based on physiological signals of the human body, and associated receiving buffers arranged to buffer signals from each receiving port, each receiving buffer having an input and an output, and associated receiving resistors conductively arranged between each receiving port and the input of each receiving buffer; and, each transmitting port having at least one transmitting port connectable to a transmitting line arranged to transmit signals to the human body, and associated transmitting buffers arranged to buffer signals supplied to each transmitting port, each transmitting buffer having an input and an output, and associated transmitting resistors conductively arranged between the output of the transmitting buffer and the transmitting port, wherein the group of resistors is formed by receiving resistors and transmitting resistors, and the resistance values ​​of the resistors in the group of resistors are pre-selected so that when an electrical short-circuit failure occurs in a resistor in the group of resistors, the current flowing through the human body does not exceed a safety threshold current.

[0004] The human body generates or transmits physiological signals that can be measured by medical probes. These physiological signals may be bioelectrical signals or electrical signals related to the human body. The human body generates or transmits signals such as brain or nerve activity. The human body may also have electrically measurable properties, such as skin electrical resistance. Alternatively, the human body may have electrically measurable properties, such as light transmittance, which can be measured by electrically driven LEDs and electrically driven photosensitive sensors. In all these examples, current is exchanged between the human body and medical devices that measure, receive, generate, supply, and / or exchange this electricity using medical devices, or the human body may be in close proximity to or in contact with such medical devices. Patient safety is protected by the IEC 60601-1 standard. One requirement of this standard is that patient safety is ensured in the event of a single failure, more specifically a single short circuit, in an electrical component, which is a part of the patient protection measures within the medical device, a part abbreviated as MOP or MOPP. For example, one MOP may fail, such as a short circuit in a resistor that is part of the MOP, and therefore medical devices need to have dual MOPs. A further requirement of the IEC60601-1 standard is that, apart from the failure of one MOP, the medical device should remain safe for the patient even if the remaining parts of the medical device outside the MOP's protection range completely fail, for example, due to a short circuit.

[0005] Medical devices typically include a medical probe with a medical probe buffer that provides an electrical buffer between the medical device and the human body. The buffer usually matches the impedance of the signal between the rest of the medical device and the human body. Additionally, the buffer usually amplifies the signal from the human body to the rest of the medical device. The buffer also serves to ensure that the medical device complies with the IEC 60601-1 standard.

[0006] Voltage is defined as the potential difference between two points. A reference potential may be provided as a reference from which the potential difference can be measured, and thus the voltage can be measured. The reference potential is transmitted to the human body by a medical probe buffer and may be commonly referred to as ground, electrical ground, or electrical patient ground.

[0007] Conductive connection should be interpreted as the existence of an electrical transmission path between electrically connected components. This electrical transmission path may include conductors that directly and electrically connect the components. Alternatively, the electrical transmission path may include, in addition to conductors, other passive electrical elements, and even active electrical elements.

[0008] A resistor is typically a physical component, usually a discrete component with a predetermined resistance to electricity. A resistor typically has two ports, and these ports usually do not have a specific orientation. In the context of safety requirements in the IEC 60601-1 standard, a resistor is typically placed as a discrete component at a certain distance, for example, on a PCB, with only the wiring on the PCB leading to and from the resistor's two ports. The distance between the wirings on the PCB and / or the insulating material ensure resistance to short circuits between the wirings. The ports of a medical probe buffer are typically connection points for connecting the medical probe buffer to a medical probe.

[0009] The resistor group typically includes all resistors conductively positioned between a port, which can be connected to a probe cable comprising a conductor and preferably a shield, and a buffer. The buffer typically has at least one output and at least one input. Depending on the direction of the signal, at least one output or at least one input of the buffer is conductively connected to the port.

[0010] The electrical components group may be defined as all components that transmit electricity in a medical probe buffer. Typically, the electrical components group includes all discrete electrical components. In some embodiments of the present invention, different buffers may be located within a single IC, thereby replacing the buffers that were integrated into the IC in the electrical components group. Safety should still be guaranteed even if an electrical short circuit occurs in one of the electrical component portions of the MOP. The resistor group is a subset of the electrical components and constitutes the MOP, but this resistor group is arranged so that even if one electrical short circuit occurs, the medical probe buffer still satisfies the requirement that the current flowing through the human body does not exceed the safety threshold current.

[0011] The safety threshold current is defined in the IEC 60601-1 standard. The safety threshold current depends on the application of the medical probe. For example, invasive medical probes are subject to different requirements than non-invasive medical probes. The pre-selection of the resistance value in a resistor is usually based on the voltage divided by the safety threshold current applicable to the medical device, more specifically the medical probe. In the context of this application, pre-selection should be understood as determining the resistance value of the resistor in advance, or before use of the medical probe buffer, and permanently setting or fixing this resistance value during use. Pre-selection is usually performed by selecting a specific resistor with a fixed resistance value and permanently incorporating that resistance value into the medical probe buffer.

[0012] Resistors attenuate the measured signal. Furthermore, resistors are noise sources that reduce the signal-to-noise ratio (SNR) of the measured signal. Placing only one resistor in the receiving or transmitting path, such as the aforementioned safety resistor for patient safety, improves the conductive path between the human body and the rest of the medical device. Furthermore, two resistors are used to ensure patient safety, such as safety resistors for patient safety, although these reduce the conductivity of the conductive path between the transmitting buffer and the human body; however, the influence of these two resistors on at least one received signal from at least one receiving port is reduced. Therefore, rearranging the resistors according to the present invention results in the technical effect of improving the SNR and / or reducing the attenuation of the received signal based on the physiological signals of the human body.

[0013] In other aspects, the medical probe comprises a medical probe buffer according to any of the embodiments described above, and at least one probe cable comprising a receiving line connectable to at least one receiving port, preferably a receiving line shield associated with the receiving line and connectable to at least one receiving shield port associated with at least one receiving port, and a transmitting line connectable to at least one transmitting port. The medical probe offers similar, and even identical, advantages to the medical probe buffer.

[0014] In other words, a medical device for measuring physiological signals in the human body comprises a medical probe arranged to measure physiological signals, a medical probe buffer according to any embodiment of the present invention arranged to receive the physiological signals measured from the probe, and a processor for processing the buffered physiological signals from the medical probe buffer. The medical device offers similar, and even identical, advantages to, the medical probe buffer. [Detailed description of exemplary embodiments] In one embodiment of a medical probe buffer, the plurality of receiving ports is at least two. Having at least two receiving ports means that the medical probe buffer comprises at least two receiving resistors, each associated with a receiving port, and at least two receiving buffers, each also associated with a receiving port. This embodiment improves the technical effect because, by typically having at least one fewer resistor in the medical probe buffer, noise sources are eliminated and attenuating elements are removed from the conductive path of the received signal. Therefore, rearranging the resistors according to the present invention results in improved technical effects, such as an improved SNR and / or reduced attenuation of each of the at least two received signals based on the respective physiological signals of the human body.

[0015] In one embodiment of a medical probe buffer, the transmitting resistor comprises a plurality of transmitting resistors connected in series, and the transmitting resistor in the resistor group is replaced by a plurality of transmitting resistors. The function of the resistors in the resistor group is to ensure that the current flowing through the patient does not exceed the safety threshold current when an electrical short-circuit fault occurs, more specifically, when a short circuit occurs in one of the resistors in the resistor group and an electrical short-circuit fault occurs. Because safety is ensured even when the resistor is short-circuited by the electrical short circuit, the remaining resistors should provide sufficient resistance so that the current flowing through the human body or patient does not exceed the safety threshold current. The safety resistance is defined as the minimum resistance of the resistor group during an electrical short circuit in which one of the resistors in the resistor group is randomly short-circuited. During normal operation, the resistor group as a whole yields a cumulative resistance, which is the sum of the resistances of the resistors in the resistor group forming a conductive path. The cumulative resistance is higher than the safety resistance. Therefore, the cumulative resistance reduces the SNR and / or increases the attenuation of the received signal based on the physiological signals of the human body. This decrease and / or increase can be reduced by increasing the number of resistors in a resistor group. Increasing the number of resistors in a resistor group while maintaining safety resistance reduces the cumulative resistance. Therefore, increasing the number of resistors in a resistor group improves the SNR and / or reduces the attenuation of the received signal based on physiological signals from the human body.

[0016] In a further embodiment of the medical probe buffer, there are two transmitting resistors connected in series. Increasing the number of resistors introduces more components that can fail, which has the disadvantage of shortening the mean time between failures. The balance between increasing and limiting the number of resistors is favorably found by pre-selecting two transmitting resistors.

[0017] In one embodiment of a medical probe buffer, the medical probe comprises a receiving shield port associated with at least one receiving port and connected to a shield arranged to electrically shield the receiving line connected to the associated receiving port; each receiving shield port having an associated shield buffer with inputs and outputs; and each receiving shield port having an associated receiving shield resistor electrically arranged between the output of the receiving shield buffer and the receiving shield port, the group of resistors being extended by the receiving shield resistors. Connecting the shield of the connected receiving line with a shield advantageously improves the SNR. The group of resistors is advantageously extended by the receiving shield resistors, which ensure that the current flowing through the human body during an electrical short-circuit fault cannot exceed a safety threshold current.

[0018] Connecting the shield of a shielded connecting line to a shielded port favorably improves the signal-to-noise ratio (SNR). The resistor group is favorably extended by shielding resistors that ensure that the current flowing through the human body during an electrical short-circuit fault cannot exceed a safety threshold current. The shielded port may be associated with the transmit line and / or receive line.

[0019] In a further embodiment of the medical probe buffer, the receiving shield resistor comprises multiple receiving shield resistors connected in series, and the receiving shield resistor in the resistor group is replaced by multiple receiving shield resistors. As previously stated, increasing the number of resistors in the resistor group favorably improves the SNR and / or favorably reduces attenuation of the received signal based on physiological signals of the human body.

[0020] In a further embodiment of the medical probe buffer, there are two receiving shielding resistors in series. As previously mentioned, increasing the number of resistors in the resistor group favorably improves the SNR and / or favorably reduces attenuation of the received signal based on physiological signals of the human body.

[0021] In a further embodiment of the medical probe buffer, at least one receive shield buffer comprises a receive shield amplifier having a receive shield amplifier output, a receive shield amplifier negative input, and a receive shield amplifier positive input, the receive shield amplifier output being conductively connected to the output of the receive shield buffer, the receive shield amplifier positive input being conductively connected to the input of the receive shield buffer, and the medical probe buffer comprises a receive shield feedback resistor, the group of resistors being extended by the receive shield feedback resistor, conductively connecting the associated receive shield port to the receive shield amplifier negative input. The shielding advantageously limits the electrical characteristics of the shield wire, such as its vulnerability to external interference. Feeding the received signal back to the shield in the shield wire advantageously reduces the resistance, preferably impedance, of the shield wire, so that the shield wire is transparent or invisible, or nearly transparent or invisible, to the receive buffer input. Limiting the electrical characteristics also reduces vulnerability to external signals, such as external noise sources radiated onto the shield wire. This reduced vulnerability advantageously improves the signal-to-noise ratio (SNR).

[0022] In one embodiment of a medical probe buffer, at least one transmit buffer comprises a transmit amplifier having a transmit amplifier output, a transmit amplifier negative input, and a transmit amplifier positive input, wherein the transmit amplifier output is conductively connected to the output of the transmit buffer, and the transmit amplifier positive input is conductively connected to the input of the transmit buffer. The medical probe buffer comprises a transmit feedback resistor that conductively connects the associated transmit port to the transmit amplifier negative input, and the resistor group is extended by the transmit feedback resistor. Feeding back the transmitted signal favorably reduces the electrical impedance of one or more output resistors. This reduced impedance favorably improves the signal-to-noise ratio (SNR).

[0023] In one embodiment of a medical probe buffer, at least one of the transmit ports is a ground port, the associated transmit buffer is a ground buffer, the input to the ground buffer is conductively connected to the system ground, and the associated transmit resistor is a ground resistor. Defining the ground advantageously provides an absolute standard for improving the identification, calculation, and / or suppression of noise sources, thereby improving the SNR.

[0024] In one embodiment of a medical probe buffer, at least one of the receiving ports is a signal input port, the associated receiving buffer is a signal buffer, preferably the output of the signal buffer is provided for further processing, and the associated receiving resistor is a signal resistor. Labeling the receiving port as a signal input port advantageously improves the identification, calculation, and / or suppression of noise sources, and consequently improves the signal-to-noise ratio (SNR).

[0025] In one embodiment of a medical probe buffer, at least one receiving port is at least two receiving ports, and at least one transmitting port is one transmitting port, the transmitting port being a ground port. This is an embodiment that favorably rearranges resistors so that fewer resistors, specifically fewer resistors in the receiving line or input, and more specifically fewer noise sources, are present in the medical probe buffer in order to improve the SNR, while still complying with the requirement that the current flowing through the human body does not exceed a safety threshold current when an electrical short-circuit fault occurs in at most one resistor in the resistor group.

[0026] In one embodiment of the medical probe buffer, the safety threshold current is a predetermined safety threshold current. The predetermined safety threshold current usually depends on whether a medical probe, which may include the medical probe buffer as part of its configuration, is invasively used on the human body or not. The predetermined safety threshold current may depend on medical standards such as, for example, the IEC60601 standard, more specifically the IEC60601-1 standard, and even more specifically the latest version, the IEC60601-1 version 3.1 standard. The resistance values of different resistors in the resistor group can be advantageously calculated based on the predetermined safety threshold current and the voltage applied or provided to the medical probe buffer.

[0027] In one embodiment of the medical probe buffer, the safety threshold current ranges from 1 μA to 1 A, preferably from 10 μA to 500 mA, more preferably from 10 μA to 500 μA, more preferably from 30 μA to 50 μA, more preferably from 35 μA to 50 μA, and most preferably less than 50 μA. These safety threshold currents are usually preselected to be in a range that is not fatal, not harmful, or does not even cause discomfort to the human being to whom the probe is applied.

[0028] In one embodiment of the medical probe buffer, the measured physiological signal is a bioelectrical signal. The bioelectrical signal can be a signal of the human body transmitted to or generated by muscles, such as, for example, myocardial contraction. The bioelectrical signal can be a signal of the human body in the brain or nervous system. The signal of the nervous system can be a signal from one of the receptors or sensory organs, such as, for example, the eyes, ears, skin, etc. The signal of the nervous system can be, for example, an output signal to muscles, skin, or organs. In an alternative embodiment, the physiological signal can be a signal from a sensor worn or inserted into the human body, such as, for example, a posture sensor for sensing the posture of the human body or measuring the movement of the human body.

[0029] In one embodiment of a medical probe buffer, the voltage supplied to at least one receiving port and at least one transmitting port is in the range of 100 mV to 100 V, preferably in the range of 500 mV to 30 V, more preferably in the range of 3 V to 24 V, and most preferably about 3 V, about 5 V, about 12 V, or about 24 V. The voltages supplied to different ports are usually preselected such that the current generated by the voltage applied across the resistor is not lethal, not harmful, or even does not cause discomfort to the human being to whom the probe is applied.

[0030] In one embodiment of a medical probe buffer, each of the resistors has a resistance value in the range of 1 KΩ to 10 MΩ, preferably in the range of 5 KΩ to 1 MΩ, more preferably in the range of 10 KΩ to 100 KΩ, and most preferably about 50 KΩ. The resistors are usually preselected such that, in combination with the applied voltage and the resulting current, they do not exceed the safety threshold current even when an electrical short circuit fault occurs. The resistors in the resistor group are preferably preselected to have the same resistance value for all the resistors in the resistor group.

[0031] In one embodiment of a medical probe buffer, the medical probe includes an IC package, and at least the buffer is disposed within the IC package. The IC package advantageously provides for the integration of at least a portion of the medical probe buffer and simplifies the medical probe buffer by reducing the number of components.

[0032] In one embodiment of a medical probe buffer, the associated receiving resistors are discrete associated receiving resistors. In a more preferred embodiment, each resistor in the resistor group is a different resistor. The different and / or discrete resistors advantageously separate the resistors from each other and limit an electrical short circuit fault to one resistor, so that two or more resistors cannot be short-circuited by a single electrical short circuit fault.

Brief Description of the Drawings

[0033] The present invention will become apparent and further elucidated by reference to the embodiments described exemplified in the following description and by reference to the accompanying drawings. [Figure 1] A schematic diagram of a conventional medical probe buffer is shown. [Figure 2] A schematic diagram of the medical probe buffer according to the present invention is shown. [Figure 3] A schematic diagram of the medical probe buffer according to the present invention is shown. The drawing is purely schematic and is not drawn to scale. Elements corresponding to elements already described in the drawing may be given the same reference numeral. [Modes for carrying out the invention]

[0034] [List of reference numbers]

[0035] [Table 1]

[0036] [Table 2]

[0037] [Table 3] [Detailed description of the drawing]

[0038] The following figures may illustrate various embodiments. Embodiments may be combined to achieve improved or enhanced technical effects. These combined embodiments may be explicitly described throughout the text, implicitly suggested, or otherwise implied.

[0039] Figure 1 schematically shows a medical probe buffer 20 according to the prior art, enclosed in a dotted frame. The medical probe buffer is arranged to buffer a first measured physiological signal in the human body 11 of a person 10. The prior art medical probe buffer comprises a first receiving port 110, a first receiving buffer 120, first receiving resistors R1a, R1b, R1c, a second receiving port 110', a second receiving buffer 120', second receiving resistors R1a', R1b', R1c', a transmitting port 150, and a transmitting buffer 160.

[0040] The first receive buffer comprises a first receive buffer input 121 and a first receive buffer output 122. The first receive resistor conductively connects the first receive port and the first receive buffer input in series. The first receive buffer output provides the first signal 105.

[0041] The second receive buffer comprises a second receive buffer input 121' and a second receive buffer output 122'. The second receive resistor conductively connects the second receive port and the second receive buffer input in series. The second receive buffer output provides the second signal 105'.

[0042] A conventional medical probe buffer further comprises a first receiving shield buffer 140, a second receiving shield buffer 140', first receiving shield resistors R2a, R2b, R2c, and second receiving shield resistors R2a', R2b', R2c'.

[0043] The first receive shield buffer comprises a first receive shield buffer input 141 and a first receive shield buffer output 142. The first receive shield resistor is conductively connected in series to the first receive shield port and the first receive shield buffer output. The first receive shield buffer input is conductively connected to the first receive buffer output.

[0044] The second receive shield buffer comprises a second receive shield buffer input 141' and a second receive shield buffer output 142'. The second receive shield resistor conductively connects the second receive shield port and the second receive shield buffer output in series. The second receive shield buffer input is conductively connected to the second receive buffer output.

[0045] Figure 2 schematically shows the medical probe buffer 100 according to the present invention with a dotted frame. The medical probe buffer is arranged to buffer a first measured physiological signal in the human body 11 of a person 10. The medical probe buffer comprises a first receiving port 110, a first receiving buffer 120, a first receiving resistor R1a, a transmitting port 150, a transmitting buffer 160, and a first transmitting resistor R4a. The first receiving buffer comprises a first receiving buffer input 121 and a first receiving buffer output 122.

[0046] The first receiving port 110 is connectable to a first receiving line 220, which is configured to transmit a first signal based on a first measured physiological signal in the human body. A first receiving buffer is associated with the first receiving port. The first receiving buffer is configured to buffer the signal from the first receiving port. A first receiving resistor is associated with the first receiving port. The first receiving resistor is electrically positioned between the first receiving port and the input of the first receiving buffer. The output of the first receiving buffer is connected to a first signal output 105, which provides a buffered first measured physiological signal, typically for further processing by a medical device or as part of a medical device.

[0047] The transmit buffer comprises a transmit buffer input 161 and a transmit buffer output 162. A transmit line 250 is connectable to a transmit port. The transmit line is arranged to transmit a signal to the human body, which may be labeled as a ground signal G or simply ground G. A first transmit resistor is associated with the transmit port. The first transmit resistor is electrically positioned between the output of the transmit buffer and the transmit port.

[0048] The resistor group Rg is formed by a first receiving resistor and a first transmitting resistor. The resistance values ​​of the resistors in the resistor group are pre-selected so that when an electrical short-circuit fault occurs in the resistors in the resistor group, the current flowing through the human body does not exceed the safety threshold current.

[0049] The resistor group is part of the MOP in the medical probe buffer. Therefore, the determination of the resistance values ​​of the resistors in the resistor group is carried out according to the worst-case scenario. Thus, firstly, in the case of the first receive buffer, the transmission path is formed by at least a transmit buffer (160), a transmit resistor (R4a), a transmit port (150), a transmit line (250), a human body (11), a receive line (220), a receive port (110), a receive resistor (R1a), and a receive buffer (120).

[0050] When pre-selecting the resistance values ​​of transmitting and receiving resistors for use as a means of patient protection (MOP), the following assumptions are made: The output resistance of the transmit buffer is assumed to be zero; The transmit port is assumed to have zero resistance; The transmission line is assumed to have zero resistance; The human body is assumed to have zero resistance; The receiving line is assumed to have zero resistance; • The receiving port is assumed to have zero resistance; and The input to the receive buffer is assumed to have zero resistance.

[0051] Under these conditions, the transmitting resistor should have a resistance value high enough to limit the current below the safety threshold current when an electrical short circuit occurs in the receiving resistor. Conversely, under these conditions, the receiving resistor should also have a resistance value high enough to limit the current below the safety threshold current when an electrical short circuit occurs in the transmitting resistor.

[0052] Based on the procedure described above, the minimum resistance values ​​for the transmitting and receiving resistors can be calculated. Furthermore, any resistance value higher than the minimum resistance value will be sufficient to satisfy this limitation. Therefore, the range of resistance values ​​is sufficient to satisfy this limitation. The resistance values ​​for the transmitting and receiving resistors are pre-selected from the range of resistance values ​​so that, in the event of an electrical short-circuit fault in either the transmitting or receiving resistor, the current flowing through the human body does not exceed the safety threshold current.

[0053] The medical probe buffer may include a second receiving port 110'. The second receiving port is connectable to a second receiving line 220' which is arranged to transmit a second signal based on a second measured physiological signal in the human body. The medical probe buffer may also include a second receiving buffer 120'. The second receiving buffer includes a second receiving buffer input 121' and a second receiving buffer output 122'. The second receiving buffer is associated with the second receiving port. The second receiving buffer is arranged to buffer the signal from the second receiving port. The medical probe buffer may also include a second receiving resistor R1a'. The second receiving resistor is associated with the second receiving port. The second receiving resistor is conductively arranged between the second receiving port and the second receiving buffer input. A second receive buffer output is connected to a second signal output 105', which typically supplies a buffered second measured physiological signal for further processing by a medical device, or as part of a medical device.

[0054] The medical probe buffer may include a second transmitting resistor R4b. The second transmitting resistor is electrically positioned between the output of the transmitting buffer and the transmitting port. The first and second transmitting resistors are typically electrically connected in series. The first and second transmitting resistors are typically discrete resistors. The second transmitting resistor is added to the resistor group. The requirement remains the same that the resistance values ​​of the resistors in the resistor group are pre-selected so that when an electrical short-circuit failure occurs in one of the resistors in the group, the current flowing through the human body does not exceed the safety threshold current. The effect of adding the second transmitting resistor to the resistor group is that the resistance value per resistor can be lower. Furthermore, the total resistance value in the resistor group may be lower because when one resistor fails due to a short circuit, the resistance values ​​of the other resistors in the resistor group are added together to satisfy the requirement that the current flowing through the human body does not exceed the safety threshold current. This lower total resistance value results in an improved signal-to-noise ratio (SNR) for the signal, specifically the received signal. Furthermore, the configuration and / or arrangement in the electrical circuit has the effect of reducing the influence of noise from resistors, more specifically from transmitting resistors, on the signal provided by at least a first receiving buffer, and preferably, if other receiving buffers are also present, on the signal provided by them.

[0055] The medical probe buffer may include receiving shield ports 130, 130' associated with receiving ports 110, 110'. The receiving shield ports are connectable to shields 221, 221'. The shields are arranged to electrically shield the receiving wires 220, 220' connected to the associated receiving ports. The medical probe buffer may also include shield buffers 140, 140'. Each of the shield buffers is associated with a receiving shield port. The shield buffers include shield buffer inputs 141, 141' and shield buffer outputs 142, 142'. The medical probe buffer may also include receiving shield resistors R2a, R2a', R2b, R2b'. Each of the receiving shield resistors is associated with a receiving shield port. The receiving shield resistors R2a, R2b are conductively arranged in series between the receiving shield buffer output 142 and the receiving shield port 130. The receive shield resistors R2a' and R2b' are conductively arranged in series between the receive shield buffer output 142' and the receive shield port 130'. In an alternative embodiment, there is only one receive shield resistor R2a, R2a' for each associated receive shield port and / or receive port. In an alternative embodiment, there are multiple receive shield resistors for each associated receive shield port and / or receive port. The resistor group is extended by the receive shield resistors. The requirement that the resistance values ​​of the resistors in the resistor group are pre-selected so that the current flowing through the human body does not exceed the safety threshold current when an electrical short-circuit fault occurs in a resistor in the resistor group remains.

[0056] At least one receive shield buffer 140, 140' may include a receive shield amplifier 125, 125'. The receive shield amplifier includes receive shield amplifier outputs 128, 128', receive shield amplifier negative inputs 127, 127', and receive shield amplifier positive inputs 126, 126'. The receive shield amplifier outputs are conductively connected to the outputs of the receive shield buffers. The receive shield amplifier positive inputs are conductively connected to the inputs of the receive shield buffers. The medical probe buffer may include receive shield feedback resistors R3a, R3a' that conductively connect the associated receive shield port and the receive shield amplifier negative input. The resistor group is extended by receive shield resistors. The requirement that the resistance values ​​of the resistors in the resistor group are pre-selected so that the current flowing through the human body does not exceed the safety threshold current when an electrical short-circuit fault occurs in a resistor in the resistor group is maintained.

[0057] At least one transmit buffer may include a transmit amplifier 165. The transmit amplifier includes a transmit amplifier output 168, a transmit amplifier negative input 167, and a transmit amplifier positive input 166. The transmit amplifier output is conductively connected to the output of the transmit buffer. The transmit amplifier positive input is conductively connected to the input of the transmit buffer. The medical probe buffer includes a transmit feedback resistor R5a which conductively connects the associated transmit port to the transmit amplifier negative input. The resistor group is extended by the transmit feedback resistor. The requirement that the resistance values ​​of the resistors in the resistor group are pre-selected so that the current flowing through the human body does not exceed the safety threshold current when an electrical short-circuit failure occurs in a resistor in the resistor group is maintained.

[0058] The medical probe 200 may comprise a medical probe buffer 100 and at least one probe cable 210, 210', 210''. The at least one cable may be a first receiving line 220, a second receiving line 220', further receiving lines, and / or a transmitting line 250, and / or comprise these. The probe cable may comprise conductors arranged to transmit signals and be connectable to a port of the medical probe buffer. The cable may comprise a shield associated with the conductors to shield them from electromagnetic interference. The shield is connectable to a shield port associated with a port to which the conductors are connectable and which is associated with the shield.

[0059] Figure 3 schematically shows the medical probe buffer 100 according to the present invention within a dotted frame. The medical probe buffer in Figure 3 is the same as the medical probe buffer in Figure 2, but enhanced with a stabilization function.

[0060] The medical probe buffer in Figure 3 comprises only one receive shield buffer 140 that supplies a feedback shield signal to the shields of the first receive line 220 and the second receive line 220'. The receive buffer comprises a receive shield buffer input 141 and a receive shield buffer output 142.

[0061] The medical probe buffer may further include a signal averaging circuit. The signal averaging circuit includes two connections connected to a first received signal and a second received signal, respectively. The two connections are conductively connected to two series resistors. The receive shield buffer input 141 is conductively connected to the electrical point connecting the two series resistors. This provides the receive shield buffer with the advantage of providing an averaged, and typically more balanced, input signal. The receive shield buffer output is conductively connected to a first receive shield 221 and a second receive shield 221' via a receive shield resistor R2a, with the first receive shield 221 and the second receive shield 221' shielding the first and second receive lines, respectively. Electrical interference typically interferes with both receive lines in approximately the same way. This embodiment offers the advantage of reducing the number of components in the medical probe buffer, thereby extending the mean time between failures. This embodiment provides the advantage of attenuating or reducing the received shield signal by averaging the electrical interference between two received signals, thereby favorably limiting extreme fluctuations in the received shield signal and preventing or limiting interference caused by the received shield signal itself.

[0062] In a group of resistors, the resistors are preferably pre-selected so that all resistors in the group have the same value. This results in a low, and even the lowest, overall resistance or total resistance for the received signal. Lowering the total resistance reduces the generated noise and, consequently, improves the signal-to-noise ratio (SNR) of the received signal.

[0063] An alternative embodiment is a medical probe buffer for buffering measured physiological signals in the human body, each receiving port having at least one receiving port connectable to a receiving line arranged to transmit signals based on physiological signals of the human body, and each receiving port having an associated receiving buffer arranged to buffer signals from the respective receiving port, each receiving buffer having an input and an output, and each receiving port having an associated conductive receiving path that provides conductivity between the associated receiving port and the associated receiving buffer input, the conductive receiving path comprising at least one receiving resistor, each receiving port and at least one transmitting line arranged to transmit signals to the human body A medical probe buffer may also be a medical probe buffer comprising a transmit port having a signal port and an associated transmit buffer arranged to buffer the signal supplied to the respective transmit port, each transmit port having an input and an output, and an associated conductive transmit path providing conduction between the associated transmit port and the associated transmit buffer output, each transmit port comprising a conductive transmit path comprising at least one transmit resistor, the resistor group being formed by resistors in a conductive receive path and resistors in a conductive transmit path, the resistance values ​​of the resistors in the resistor group being pre-selected so that when an electrical short-circuit failure occurs in a resistor in the resistor group, the current flowing through the human body does not exceed a safety threshold current. The arrangement of resistors in this embodiment or other embodiments, more specifically the positioning of resistors, ensures that an electrical short circuit in one of the electrical components, such as a buffer or resistor, does not cause the current flowing through the human body to exceed a safety threshold current. This alternative embodiment may produce the same or equivalent technical effects or advantages as described. The alternative embodiment may be a combination of features from other embodiments or features of other embodiments to obtain the same or equivalent technical effects or advantages as described.

[0064] Examples, embodiments, or any features, whether indicated as non-limiting or not, should not be understood as limiting the claimed invention. It should be noted that the drawings are purely schematic and not drawn to scale. In the drawings, elements corresponding to elements already described may have the same reference numeral.

[0065] For example, the term “substantially” as used herein, such as “substantially all emissions” or “substantially constitutes,” will be understood by those skilled in the art. The term “substantially” may also include embodiments with “entirely,” “completely,” “all,” etc. Thus, in embodiments, the adjective “substantially” may be omitted. Where applicable, the term “substantially” may also be related to 90% or more, for example 95% or more, more specifically 99% or more, and more specifically 99.5% or more, and include 100%. The term “to comprise” also includes embodiments where the term “to comprise” means “to consist of.”

[0066] The term “functionally” will be understood and clear to those skilled in the art. The terms “substantially” and “functionally” may also include embodiments with “overall,” “completely,” “all,” etc. Thus, in embodiments, the adjective “functionally” may be omitted. For example, when used in “functionally parallel,” those skilled in the art will understand that the adjective “functionally” includes the term “substantially,” as described above. In particular, “functionally” should be understood to include the configuration of the feature that enables the feature to function as if the adjective “functionally” were not attached to it. The term “functionally” is intended to include variations of the feature to which “functionally” refers, such variations that, in the functional use of the feature, and possibly in combination with other relevant features in the present invention, the combination of features is operable or functional. For example, if an antenna is functionally coupled to or functionally connected to a communication device, the received electromagnetic signals received by the antenna can be used by the communication device. The term "functionally," when used, for example, in "functionally parallel," is used not only to encompass complete parallelism but also to encompass embodiments that are encompassed by the term "substantially" as described above. For example, "functionally parallel" relates to embodiments in which, during operation, the components function as if they were, for example, parallel. This includes embodiments in which, to a person skilled in the art, it is evident that they operate as if they were parallel within their intended field of use.

[0067] Furthermore, terms such as "first," "second," and "third" in the specification and claims are used to distinguish similar elements from each other and are not necessarily used to describe a sequence or chronological order. Terms used in this manner are interchangeable under appropriate circumstances, and it should be understood that embodiments of the invention described herein may operate in a different order than that described or illustrated herein.

[0068] The devices or apparatus described herein are described in particular in operation. As will be apparent to those skilled in the art, the present invention is not limited to operating methods or devices in operation.

[0069] The embodiments described above are illustrative rather than limiting, and it should be noted that those skilled in the art can design many alternative embodiments without departing from the scope of the appended claims. Any reference numerals in parentheses in the claims shall not be construed as limiting the claims. The use of the verb “equip” and its conjugations shall not preclude the existence of elements or processes other than those described in the claims. The articles such as “a” or “an” preceding an element shall not preclude the existence of multiple elements. The present invention may be carried out using hardware comprising multiple different elements and using a appropriately programmed computer. In claims for equipment or devices listing multiple means, some of these means may be embodied by a single identical hardware item. The mere fact that certain means are described in different dependent claims shall not imply that combinations of these means cannot be used advantageously.

[0070] The present invention further applies to apparatus or equipment having one or more of the characteristic features described in the specification and / or shown in the accompanying drawings. The present invention further relates to methods or processes having one or more of the characteristic features described in the specification and / or shown in the accompanying drawings.

[0071] The various aspects described in this patent can be combined to provide further advantages. Furthermore, some features can form the basis for one or more divisional applications.

Claims

1. A medical probe buffer (100) for buffering measured physiological signals in the human body (11), At least one receiving port (110, 100') connectable to a receiving line (220, 220') arranged to transmit signals based on the physiological signals of the human body, Each receiving port has associated receiving buffers (120, 120') arranged to buffer the signals from each of the receiving ports, each receiving buffer having an input (121, 121') and an output (122, 122'), Each receiving port has associated receiving resistors (R1a, R1a') electrically disposed between the respective receiving port and the input of the respective receiving buffer, At least one transmission port (150) connectable to a transmission line (250) arranged to transmit signals to the human body, Each transmit port has an associated transmit buffer (160) arranged to buffer the signal supplied to each of the transmit ports, each transmit buffer having an input (161) and an output (162), Each transmit port has associated transmit resistors (R4a, R4b) electrically disposed between the output of the transmit buffer and the transmit port. Equipped with, The resistor group (Rg) is formed by the receiving resistor and the transmitting resistor, The resistance values ​​of the resistors in the group of resistors are pre-selected so that when an electrical short-circuit failure occurs in one of the resistors in the group of resistors, the current flowing through the human body does not exceed a safety threshold current. Medical probe buffer.

2. A medical probe buffer according to a prior claim, A medical probe buffer having at least two of the aforementioned receiving ports.

3. A medical probe buffer according to any of the preceding claims, The transmitting resistor comprises a plurality of transmitting resistors connected in series, In the aforementioned group of resistors, the transmitting resistor is replaced by the plurality of transmitting resistors, medical probe buffer

4. A medical probe buffer according to a prior claim, The two transmitting resistors connected in series are a medical probe buffer.

5. A medical probe buffer according to any of the preceding claims, A receiving shield port (130, 130') associated with the at least one receiving port and connectable to a shield (221, 221') arranged to electrically shield the receiving lines (220, 220') connected to the associated receiving port, Each receiving shield port has an associated shield buffer (140, 140') having inputs (141, 141') and outputs (142, 142'), Each receive shield port has associated receive shield resistors (R2a, R2a', R2b, R2b') electrically disposed between the output of the receive shield buffer and the receive shield port. Equipped with, The group of resistors is extended by the receiving shield resistor, forming a medical probe buffer.

6. A medical probe buffer according to a prior claim, The receiving shield resistor comprises a plurality of receiving shield resistors connected in series, A medical probe buffer in which the receiving shield resistor in the group of resistors is replaced by the plurality of receiving shield resistors.

7. A medical probe buffer according to a prior claim, The plurality of receiving shield resistors connected in series are two, a medical probe buffer.

8. A medical probe buffer according to any one of the preceding claims 5 to 7, The at least one receive shield buffer includes a receive shield amplifier (125, 125') having a receive shield amplifier output (128, 128'), a receive shield amplifier negative input (127, 127'), and a receive shield amplifier positive input (126, 126'), The output of the receiver shield amplifier is electrically connected to the output of the receiver shield buffer. The positive input of the receiving shield amplifier is electrically connected to the input of the receiving shield buffer. The medical probe buffer comprises a receive shield feedback resistor (R3a, R3a') which electrically connects the associated receive shield port and the negative input of the receive shield amplifier. The group of resistors is extended by the receiving shield feedback resistor, forming a medical probe buffer.

9. A medical probe buffer according to any of the preceding claims, The at least one transmit buffer includes a transmit amplifier (165) having a transmit amplifier output (168), a transmit amplifier negative input (167), and a transmit amplifier positive input (166). The output of the transmit amplifier is electrically connected to the output of the transmit buffer. The positive input of the transmit amplifier is electrically connected to the input of the transmit buffer, The medical probe buffer includes a transmit feedback resistor (R5a) that electrically connects the associated transmit port and the negative input of the transmit amplifier. The aforementioned group of resistors is a medical probe buffer extended by the transmit feedback resistor.

10. A medical probe buffer according to any of the preceding claims, One of the at least one transmitting port is a ground port, The aforementioned related transmit buffer is a ground buffer, The input of the ground buffer is electrically connected to an external ground. The aforementioned related transmitting resistor is a ground resistor, a medical probe buffer.

11. A medical probe buffer according to any of the preceding claims, One of the at least one receiving port is a signal input port, The aforementioned related receive buffer is a signal buffer, Preferably, the output of the signal buffer is provided for further processing. The aforementioned related receiving resistor is a signal resistor, a medical probe buffer.

12. A medical probe buffer according to any of the preceding claims, The aforementioned at least one receiving port is at least two receiving ports, The aforementioned at least one transmission port is one transmission port, The aforementioned transmission port is a ground port, a medical probe buffer.

13. A medical probe buffer according to any of the preceding claims, The safety threshold current is a predetermined safety threshold current in a medical probe buffer.

14. A medical probe buffer according to any of the preceding claims, A medical probe buffer wherein the safety threshold current is in the range of 1 μA to 1 A, preferably in the range of 10 μA to 500 mA, more preferably in the range of 10 μA to 500 μA, more preferably in the range of 30 μA to 50 μA, more preferably in the range of 35 μA to 50 μA, and most preferably less than 50 μA.

15. A medical probe buffer according to any of the preceding claims, The measured physiological signal is a bioelectrical signal, used in medical probe buffers.

16. A medical probe buffer according to any of the preceding claims, A medical probe buffer wherein the voltage supplied to the at least one receiving port and the at least one transmitting port is in the range of 100 mV to 100 V, preferably in the range of 500 mV to 30 V, more preferably in the range of 3 V to 24 V, most preferably about 3 V, about 5 V, about 12 V, or about 24 V.

17. A medical probe buffer according to any of the preceding claims, Each of the resistors has a resistance value in the range of 1 kΩ to 10 MΩ, preferably in the range of 5 kΩ to 1 MΩ, more preferably in the range of 10 kΩ to 100 kΩ, and most preferably about 50 kΩ, for a medical probe buffer.

18. A medical probe buffer according to any of the preceding claims, A medical probe buffer comprising an IC package, wherein at least the buffer is located within the IC package.

19. A medical probe buffer according to any of the preceding claims, The aforementioned related receiving resistor is a different related receiving resistor, a medical probe buffer.

20. A medical probe (200), A medical probe buffer (100) according to any one of the preceding claims 1 to 19, At least one probe cable, A receiving line that can be connected to at least one of the receiving ports, Preferably, a receiving line shield that is connected to the receiving line and to the at least one receiving shield port associated with the at least one receiving port, A transmission line that can be connected to the at least one transmission port and A probe cable equipped with at least one probe cable and A medical probe equipped with [features / technology].

21. A medical device (300) for measuring physiological signals of the human body, A medical probe arranged to measure the aforementioned physiological signals, A medical probe buffer according to any one of claims 1 to 19, which is arranged to receive the measured physiological signal from the probe, A processor for processing the buffered physiological signals from the medical probe buffer. A medical device equipped with the following features.

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