Touch sensor device for a medical instrument, medical instrument and method for operating a touch sensor device for a medical instrument

Abstract

The invention relates to a touch sensor device (7) for a medical instrument (1), comprising a touch sensor (8), a control unit (9) which is configured to detect operating events (10) at an operating surface (6) of the touch sensor device by evaluating sensor data of the touch sensor, and an error detection apparatus (12) for detecting errors involving the control unit. The error detection apparatus is configured to (a) directly measure common mode interference if the error is caused by common mode interference, and / or (b) generate an alternating voltage signal (30) which is applied to the touch sensor, detect an influence caused by an operating event (10), and check whether the operating event can be detected by means of the error detection apparatus (12) but not by means of the control unit (9), wherein a fault in the control unit (9) is identified if this is the case.

Description

Technical Field

[0001] The present invention relates to a touch sensor device for a medical instrument, a medical instrument having such a touch sensor device, and a method for operating such a touch sensor device for the medical instrument. Background Technology

[0002] Medical instruments may have at least one safety-critical function, for which at least one safety measure is provided. A safety-critical function may, for example, include activating exposure to X-ray radiation, gamma radiation, or other types of radiation used in medical applications. Safety measures, for example, should prevent the detection of operational events associated with the medical instrument's operating equipment, even if the operational event was not performed by the user of the medical instrument or not performed by the user as detected. Alternatively or additionally, safety measures, for example, should prevent the operational event from going undetected due to an undetected malfunction of the operating equipment.

[0003] Safety measures are particularly important when the operating device is a touch sensor device, such as one that includes capacitive or resistive touch sensors, which are configured to detect operational events on the operating surface of the touch sensor device. This is because, for example, the detection principle of a touch sensor device is sensitive to environmental interference, causing the control unit of the touch sensor device to provide erroneous results, for example, due to interference. Alternatively or additionally, touch sensor devices are more susceptible to electronic malfunctions than mechanical operating devices such as buttons or keys, which can lead to unintended failures in the control unit at any time. Summary of the Invention

[0004] The object of this invention is to provide a solution by means of which errors involving the control unit of a touch sensor device can be reliably detected.

[0005] The objective is achieved by the touch sensor device for a medical instrument according to the present invention, the medical instrument having the touch sensor device, and the method for operating the touch sensor device for the medical instrument.

[0006] A first aspect of the present invention relates to a touch sensor device for a medical instrument. The touch sensor device is a device configured to detect whether an object and / or person is in contact with the operating surface of the touch sensor device. Alternatively, the touch sensor device may be referred to as a tactile sensor device or a touch control sensor device. The touch sensor device includes at least one touch sensor, a control unit, and an error detection device for detecting errors involving the control unit. The control unit is configured to detect an operational event at or on the operating surface of the touch sensor device by evaluating sensor data from the touch sensor. The touch sensor may, for example, include capacitive and / or resistive sensors and / or force sensors. Thus, the touch sensor responds, for example, to touch, force application, and / or pressure, wherein touch, force application, and / or pressure are each understood as at least a part of an operational event. Therefore, the touch sensor device may employ different techniques known to touch sensor devices for detecting operational events. Alternatively, the touch sensor may be referred to as a touch control sensor or a touch-sensitive sensor. Alternatively, the control unit may be referred to as a touch controller or a touch control device. Sensor data detected by the touch sensor can be transmitted within the touch sensor device to the control unit, where the control unit evaluates it to determine whether to detect an operation event or not to detect an operation event if it is uncertain.

[0007] According to feature (a), the error detection device is configured to directly measure common-mode interference when the error is caused by common-mode interference. Common-mode interference should be understood as interference voltage and / or interference current, which is generated, for example, by another device and can affect, for example, distort sensor data received by the control unit, especially if that other device is not a component of the touch sensor device and / or a medical instrument, wherein the touch sensor device includes or is associated with the touch sensor device. For example, the other device, configured as another medical instrument, generates a voltage signal having a frequency at least partially located within the same frequency range as, for example, an electric field applied to the operating surface in the case of a capacitive touch sensor to detect an operational event. Therefore, common-mode interference affects the sensor data transmitted by the touch sensor to the control unit. Alternatively, common-mode interference can be referred to as common-mode noise.

[0008] The error detection device is configured to directly measure common-mode interference by detecting the voltage generated between a first reference potential at the ground terminal of the reference control unit and a second reference potential at the ground terminal of the isolation power supply of the reference touch sensor device. Therefore, the error detection device is configured to measure the difference between the first and second reference potentials, where the measured difference is the detected voltage. The isolation power supply should be understood as a component of the touch sensor device that is electrically isolated relative to the rest of the touch sensor device, particularly relative to the control unit. Therefore, the isolation power supply is, for example, grounded, such that the ground terminal of the reference isolation power supply can, for example, be ground potential. The ground terminal of the control unit should also be understood as being grounded. The ground terminal of the control unit can, for example, also be grounded.

[0009] Feature (a) is based at least on the understanding that the valid signal describing an operational event at the operating surface is transmitted only between the touch sensor and the control unit, but not further to areas of the touch sensor device, such as those isolated relative to the touch sensor. Therefore, the first and second reference potentials considered when detecting voltage are unaffected by the valid signal, but are affected by common-mode interference. This is because common-mode interference is transmitted from the control unit to other components and / or electrical connections within the touch sensor device. Therefore, once common-mode interference occurs, it can be detected by means of an error detection device unaffected by other signals such as the valid signal, since the error detection device is located between the control unit and the isolated power supply, thereby located in the isolated area of ​​the touch sensor device. If common-mode interference is detected, it can be inferred that at least an error due to common-mode interference should be expected, especially an error caused by common-mode interference. Because common-mode interference affects the valid signal, errors involving the control unit exist, as the accuracy of determining the operational event is affected, thus resulting in errors.

[0010] An isolation region can be understood as a region of a touch sensor device that is electrically isolated from, and thus decoupled from, at least the control unit and the touch sensor, and, if necessary, electrically isolated from, other components of the touch sensor device, such as the power supply unit of the touch sensor device.

[0011] Alternatively or additionally, according to feature (b), the error detection device is configured to: generate an AC voltage signal when the error is caused by a fault in the control unit; apply the generated AC voltage signal to the touch sensor through an isolation area of ​​the touch sensor device; and detect the effect of the applied AC voltage signal caused by an operational event. That is, an artificial AC voltage signal of known voltage and frequency is applied, wherein the AC voltage signal is not applied directly to the control unit or the touch sensor, but is transmitted to the touch sensor through the isolation area and the control unit. For this purpose, the AC voltage signal may, for example, be applied to the ground connection of the control unit. This causes the effective signal describing the operational event and transmitted from the touch sensor to the control unit to interact with the applied AC voltage signal, thereby modulating the effective signal of the touch sensor.

[0012] The error detection device is configured to check whether an operational event can be detected by the error detection device but not by the control unit, and if so, that is, if the operational event can be detected by the error detection device but not by the control unit, then a fault in the control unit is identified. Therefore, the error detection device provides the feasibility to determine whether an operational event at the operating surface has been detected by the control unit. If the control unit fails to detect the operational event, even though an operational event has occurred, this is identified based on the influence of the AC voltage signal, and the control unit is considered faulty. Alternatively, the fault of the control unit can be referred to as an error and / or failure of the control unit. A fault of the control unit involves an error in the control unit.

[0013] If a fault is detected, prompts and / or warnings may be output to the user, and / or the medical device or at least one of its preset functions may be deactivated.

[0014] Therefore, an error detection device provides an example of checking the function of the control unit and identifying whether there is interference in the form of common-mode interference caused by other devices, and / or whether the control unit itself is faulty and thus limited in its function. Here, common-mode interference is considered to be related to errors in the control unit because it causes distortion of detected operating events; conversely, a fault in the control unit causes operating events to generally no longer be detectable, at least temporarily, by means of the control unit. Therefore, errors in the control unit involving the touch sensor device can be reliably detected by means of the touch sensor device.

[0015] One embodiment for feature (a) proposes that the error detection device includes at least one capacitor disposed between a voltage drop unit and an isolation power supply unit of the error detection device. Furthermore, the error detection device includes a voltage drop unit. Alternatively, the voltage drop unit may be referred to as a measuring impedance or a measuring impedance unit. The voltage drop unit is a component at which a voltage drop between first and second reference potentials is generated. Alternatively, the voltage drop unit may be referred to as a voltage generating unit. The voltage drop unit may have at least one resistor, at least one coil, and / or at least one capacitor, and is configured to determine the voltage drop or generation at the voltage drop unit by comparing a voltage upstream of the voltage drop unit with a voltage downstream of the voltage drop unit.

[0016] In a preferred example, the capacitor is a Y capacitor or a capacitor of other types, which is configured, for example, to be connected in parallel with at least one transformer and / or another isolation element of the touch sensor device, wherein at least one preset safety requirement for the touch sensor device is particularly satisfied.

[0017] The error detection device includes a voltage detection unit configured to detect and quantify a voltage generated or dropped at a voltage drop unit, i.e., the voltage between a first reference potential and a second reference potential. Furthermore, the error detection device includes an evaluation unit configured to evaluate the voltage detected by means of the voltage detection unit. The voltage detection unit and the evaluation unit can be two separate components, or they can be understood as a common voltage detection and evaluation unit. Alternatively, the voltage detection unit can be understood as a measuring device for measuring voltage, and the evaluation unit can be understood as an analytical device for evaluating the detected voltage. In one example, the evaluation unit may have an electrical connection to a control unit, and via said electrical connection, for example, generate data such as control signals to the control unit of a touch sensor device. Therefore, the error detection device includes at least one capacitor, a voltage drop unit (e.g., measuring impedance), a voltage detection unit, and an evaluation unit to provide the aforementioned functionality, i.e., detecting a voltage describing common-mode interference.

[0018] It can be proposed that the capacitor is electrically coupled, for example, to the voltage drop unit on a first side, and electrically coupled, for example, to the connection to the ground terminal of the isolation power supply on an opposite second side. Furthermore, the voltage drop unit may be connected, for example, to the connection to the ground terminal of the control unit, on a side away from the capacitor, such as a ground connection or a ground connection, which is coupled to the control unit. This makes it clear how the error detection device can be configured in detail for detecting common-mode interference.

[0019] Another embodiment includes an evaluation unit configured to check whether a detected voltage exceeds a preset voltage limit when evaluating the voltage. Furthermore, the evaluation unit is configured to provide a trigger signal for at least one of the following measures if the detected voltage exceeds the preset voltage limit. Alternatively, the trigger signal may be referred to as an operation command for the control unit and is transmitted to the control unit, for example, by the evaluation unit. Another prerequisite for providing the measures may be that the touch sensor and the control unit are configured for capacitively determining the operation event.

[0020] Measures may include: transforming the frequency used by the touch sensor to determine the operation event such that the frequency used by the touch sensor is different from the frequency of a detected voltage above a preset voltage limit, i.e., different from the frequency associated with detected common-mode interference. Therefore, measures include: transforming the frequency of the AC voltage applied to the operating surface for capacitive detection of the operation event at the operating surface by means of the touch sensor, so that the AC voltage frequency does not become confused with the frequency of common-mode interference. It may be proposed that the transformed frequency and the frequency of the common-mode interference must differ by a preset minimum frequency difference.

[0021] Alternatively or additionally, the measure may include ignoring detected operational events whenever the detected voltage is higher than a preset voltage limit. Thus, for example, the control unit may be preset so that no detected operational events are currently considered due to sufficiently large common-mode interference. Therefore, the operational events may be deleted or overwritten, for example. Alternatively, the ignoring may include the absence of currently detected operational events. The ignoring is performed temporarily while the detected voltage is higher than the preset voltage limit. The ignoring can end once the detected voltage is lower than or corresponds to the preset voltage limit. This results in the temporary inability to detect user operational events, preventing the potential impact of non-existent operational events simulated solely by common-mode interference on, for example, medical instruments.

[0022] In contrast to this alternative or additional approach, the following measure can be proposed: disabling or suspending the distance mode. In distance mode, operational events performed at intervals from the operating surface can be detected. Distance mode can be an additional function of the touch sensor and, for example, enables long-distance operability of the touch sensor device. If such a distance mode exists, it can be turned off or stopped because it typically requires a low signal-to-noise ratio, which cannot be achieved when the voltage exceeds a preset voltage limit.

[0023] Alternatively or additionally, measures may include: disabling or suspending a glove mode in which gloved operations can be detected. For example, glove usability requires a low signal-to-noise ratio, which cannot be achieved under conditions of high common-mode interference, i.e., when the voltage exceeds a preset voltage limit. Therefore, the glove mode may be at least temporarily disabled or suspended. Once the detected voltage falls below or corresponds to the preset voltage limit, the distance mode and / or glove mode may be reactivated.

[0024] Alternatively or additionally, a prompt notification may be proposed as a measure. The prompt notification may, for example, be displayed on the operating surface. In contrast to this alternative or additional method, the prompt notification may be output acoustically and / or tactilely, for example, through vibration of the operating surface. The prompt notification indicates an error caused by common-mode interference; that is, the prompt notification indicates, for example, that another device in the surrounding environment affects and, if necessary, distorts the detection of the operational event by means of a touch sensor device. Furthermore, the prompt notification may request the shutdown or suspension of another device to at least reduce common-mode interference. Additionally, the prompt notification may, for example, include: currently disabling or suspending glove mode and / or distance mode, and / or currently ignoring the operational event, for example, due to common-mode interference.

[0025] Alternatively or additionally, at least one method for reducing interference, particularly spread spectrum, can be proposed as a measure. Thus, spread spectrum techniques can be used to resist common-mode interference and, for example, at least partially suppress it. However, a disadvantage of such interference reduction methods is that they can affect operability, thereby affecting the touch sensor, increase current consumption, and / or introduce at least one other disadvantage. Therefore, for example, it can be proposed to take the measure only when the detected voltage is higher than another voltage limit, which is greater than the aforementioned voltage limit.

[0026] Different voltage limit values ​​can be set for various measures. For example, a higher voltage limit value can be set compared to the voltage limit value for changing the start trigger frequency and / or outputting a notification prompt, in order to, for example, trigger the activation of methods to reduce interference and / or disable or pause distance mode and / or glove mode. Alternative combinations of voltage limit values ​​and / or other effects are possible. Typically, the voltage limit value is a value associated with the control unit and / or the touch sensor used. Therefore, in one example, instead of setting the same voltage limit value for all touch sensor devices, a voltage limit value is set that can be different, high or low, depending on the touch sensor device and / or other components of the touch sensor device.

[0027] Another embodiment proposes that the touch sensor device has an intermediate component disposed between the control unit and the isolated power supply. An error detection device is configured to detect a voltage generated as common-mode interference between a first reference potential at the ground terminal of the reference control unit and a third reference potential at the ground terminal of the reference intermediate component. The third reference potential may be less strongly coupled to ground potential compared to the second reference potential of the reference isolated power supply. The third reference potential is, for example, located between the first and second reference potentials. If the touch sensor device has additional components, an intermediate potential, referred to herein as the third reference potential, can be provided such that the capacitor, for example, does not need to be directly coupled to the isolated power supply on one side, but is instead, for example, first coupled to the ground terminal of the intermediate component, and then coupled to the isolated power supply via the ground terminal of the intermediate component. However, this is contingent upon a potential difference existing between the first and third ground terminals, and the third ground terminal being isolated from the control unit and the touch sensor, thus associated with an isolated region. This enables various configurations of the error detection device in the touch sensor device.

[0028] Furthermore, feature (a) includes the following embodiment: a local ground terminal of the first reference potential reference control unit is configured, the local ground terminal being provided via a ground terminal connection between the power supply unit of the touch sensor device and the control unit, i.e., a ground connection or earth connection. The power supply unit may, for example, be configured to convert an AC voltage provided by an isolated power supply device into a DC voltage, and to provide the DC voltage via a voltage supply connection between the power supply unit and the control unit.

[0029] In one example, the voltage drop unit of the error detection device is now coupled to a ground connection, i.e., the ground connection is intercepted. It is expected, through the connection to the control unit and the connection between the control unit and the touch sensor, that common-mode interference, rather than a valid signal, affects the ground connection between the power supply unit and the control unit, and at that point, for example, causes a potential rise. This demonstrates an easily achievable manner and method for providing a ground connection to the control unit.

[0030] In conjunction with feature (b), the following implementation is proposed: The error detection device includes another control unit. This other control unit is configured to generate an AC voltage signal. For example, the other control unit may be configured as a capacitive control unit for capacitive detection of operational events. The other control unit generates the AC voltage signal and forwards it to an isolation area of ​​the touch sensor device; that is, the other control unit transmits the AC voltage signal to the isolation area. The AC voltage signal is preset with reference to the ground terminal of the other control unit. The other control unit, for example, has a connection to the ground terminal, particularly to earth potential or to an intermediate potential. Therefore, the AC voltage signal is, for example, unaffected by common-mode interference caused by another device, if such another device is present, and does not cause any impact on the control unit and the touch sensor, thus providing a meaningful method for generating the AC voltage signal.

[0031] In another embodiment, another control unit is configured for capacitively determining operational events; however, the touch sensor and control unit are configured for resistively determining operational events. Therefore, the functionality of the resistive control unit can be checked according to feature (b). This is advantageous because such a control unit may be particularly susceptible to malfunctions. The other control unit does not have its own touch sensor but uses the same touch sensor device as the control unit.

[0032] Alternatively or additionally, the touch sensor and control unit can be configured similarly for capacitively determining operational events, where isolation between the other control unit and the control unit is assumed. Therefore, various combinations of the other control unit and the control unit are feasible.

[0033] Furthermore, in one embodiment, at least one capacitor may be provided between the isolation area of ​​another control unit and the touch sensor device. The capacitor is, for example, a Y capacitor. The at least one capacitor may, for example, have a capacitance between 1 nanofarad and 10 nanofarads. An error detection device is configured to detect the effect of an operational event on an applied AC voltage signal by means of an increase in current in the at least one capacitor. This demonstrates how an error detection device can be used to detect the effect of an operational event on an applied AC voltage signal. Here, the capacitor is a cost-effective and space-saving component.

[0034] In another embodiment, the error detection device is configured to determine whether a detected current rise at the capacitor exceeds a preset current rise limit. An operational event is detected if, and especially only if, the detected current rise exceeds the preset current rise limit. Therefore, the error detection device detects the operational event as an operational event only when the detected current rise exceeds the preset current rise limit. The current rise limit may, for example, depend on the control unit or the touch sensor, and thus on the touch sensor device. Once the current rise exceeds the current rise limit, a fault in the control unit is considered identified. Therefore, the identification of a fault in the control unit according to feature (b) is based on a relatively easily implemented measurement within the error detection device, which is particularly advantageous.

[0035] Furthermore, one embodiment may include: relating to feature (b), the error detection device is configured to spread the AC voltage signal to a frequency range having a preset minimum frequency range width by means of spread spectrum. It is therefore particularly meaningful that the control unit and touch sensor are configured, for example, as a multi-touch system, i.e., a touch sensor capable of simultaneously detecting multiple touches on the operating surface as operation events. Multi-touch control devices and multi-touch touch sensors typically do not use only a single preset frequency, but rather a frequency range including multiple individual frequencies. Therefore, multi-touch systems are relatively sensitive to interference signals, necessitating the division of the AC voltage signal to spread it to multiple frequencies.

[0036] Another embodiment proposes that the touch sensor device includes a touch sensor having a first control unit, wherein the first touch sensor and the first control unit are configured for capacitively determining an operation event. Furthermore, the touch sensor device may include a second touch sensor having a second control unit, wherein the second touch sensor and the second control unit are configured for detecting force input to determine an operation event. Therefore, it is proposed that a capacitive touch sensor and a force sensor are provided. Thus, the second touch sensor and the second control unit are configured to determine an operation event as an operation event based on force input. Alternatively or additionally, the second touch sensor and the second control unit may be configured for resistively detecting the operation event.

[0037] The error detection device constitutes a means of identifying at least one fault in the control unit of the second control unit, i.e., the force sensor. Therefore, it can be proposed to combine two methods for detecting operational events in the same touch sensor device, such that operational events can be detected, for example, not only when pressing on the operating surface but also when touching the operating surface, by means of one combination of the touch sensor and the control unit. Now, by means of the error detection device, for example, only one combination of the two combinations of the touch sensor and the control unit can be monitored for faults in the control unit, in order to provide enhanced safety requirements for specific functions of medical instruments, but not to monitor any operational events, such that the capacitive control unit used for capacitively determining operational events is not monitored for faults in the capacitive control unit according to feature (b). This results in a cost-effective touch sensor device implemented with lower costs, because only a portion of the touch sensor device can be focused on.

[0038] Furthermore, one embodiment proposes dividing the operating surface into at least one first sub-region and at least one second sub-region. A touch sensor device is configured to detect operating events in at least one first sub-region by means of, in particular only by means of, a first touch sensor and a first control unit, and in at least one second sub-region by means of, in particular only by means of a second touch sensor and a second control unit. The operating surface may, for example, have a first half and a second half, wherein on the first half, for example only, an operating gesture including touching the operating surface is considered, thus capacitively detectable; conversely, on the second half, thus in the second sub-region, only force input is considered, thus detecting pressure on the operating surface as an operating event. Alternatively, with respect to the first and second halves, first and second sub-regions of arbitrary shape may be provided, which may, for example, be alternately and / or at least partially surrounding each other on the operating surface. In a preferred example, exactly one first sub-region and exactly one second sub-region may be provided. This results in a clear and intuitively understandable spatial separation between the first and second sub-regions.

[0039] The reason for this embodiment is at least that, although force sensors typically have a smaller spatial resolution compared to capacitive touch sensors, they are more resistant to, for example, wet fingers or liquids. Therefore, unlike the first sub-region, the second sub-region can be operated, for example, with wet or damp fingers and / or in the presence of liquid on the operating surface. This thus enables a particularly robust design of the touch sensor device relative to operating events caused by or in combination with liquid or moisture. Therefore, in addition to identifying faults in the control unit, it is possible to prevent erroneous operation from being triggered by liquid on the operating surface, because the force sensor can detect operating events independently of liquid.

[0040] In an additional embodiment, at least one second sub-region is configured for operational events relating to at least one safety-related function of the medical instrument, which can be determined by means of a touch device. If the medical instrument is, for example, an X-ray device, X-ray radiation can always be activated, for example, only when the second sub-region is operated. Emergency stop and / or emergency shutdown buttons can also be understood as safety-related functions, and should be operable in the second sub-region.

[0041] Another aspect of the present invention relates to a medical instrument having a touch sensor device as described above.

[0042] Another aspect of the present invention relates to a method for operating a touch sensor device for a medical instrument. The touch sensor device corresponds to the aforementioned touch sensor device, that is, the touch sensor device includes a touch sensor, a control unit, which detects operational events at the operating surface of the touch sensor device by means of the control unit through evaluating sensor data from the touch sensor, and includes an error detection device for detecting errors involving the control unit. If the error is caused by common-mode interference, the error detection device directly measures the common-mode interference. This is done by detecting a voltage generated between a first reference potential at the ground terminal of the reference control unit and a second reference potential at the ground terminal of the isolation power supply of the reference touch sensor device. Alternatively or additionally, if the error is caused by a fault in the control unit, the error detection device can generate an AC voltage signal, apply the generated AC voltage signal through the isolation region of the touch sensor device to the control unit, detect the effect of the applied AC voltage signal caused by the operational event, and check whether the operational event can be detected by means of the error detection device but not by means of the control unit; if this is the case, a fault in the control unit is identified.

[0043] The touch sensor device according to the invention can be configured for or included in a medical instrument. Alternatively, the touch sensor device can be included in or configured for any other instrument or device. Therefore, it can be applied in other technical fields, such as in home appliances, mobile terminal devices, vehicles, and / or entertainment electronic devices.

[0044] The embodiments described in conjunction with the touch sensor device are applicable, if applicable, to the medical instruments and methods according to the invention. The invention includes combinations of the described embodiments.

[0045] In this disclosure, the control unit and / or evaluation unit may be configured as part of a data processing system or a data processing apparatus. A data processing apparatus is particularly understood as a data processing apparatus containing processing circuitry. Therefore, a data processing apparatus can, in particular, process data for performing computational operations. Operations may also be included, where necessary, to perform access to instructions on a data structure such as a look-up table (LUT), similar to data processing procedures implemented in hardware.

[0046] Data processing devices may, in particular, include one or more computers, one or more microcontrollers, and / or one or more integrated circuits, such as one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more system-on-a-chip (SoCs). Data processing devices may also include one or more processors, such as one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, particularly one or more digital signal processors (DSPs). Data processing devices may also include physical or virtual clusters of computers or other units among the mentioned units.

[0047] In different embodiments, the data processing device includes one or more hardware and / or software interfaces and / or one or more storage units.

[0048] The storage cell can be designed as a volatile data memory, such as dynamic random access memory (DRAM) or static random access memory (SRAM), or a non-volatile data memory, such as read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or flash EEPROM, ferroelectric random access memory (FRAM), magnetoresistive random access memory (MRAM), or phase-change random access memory (PCRAM).

[0049] In this invention, nouns and pronouns referring to people are generally not limited to a specific gender. Attached Figure Description

[0050] The attached diagram shows:

[0051] Figure 1 A schematic diagram of a medical instrument with a touch sensor device is shown.

[0052] Figure 2 A schematic diagram showing feature (a) for an error detection device, and

[0053] Figure 3 A schematic diagram of feature (b) for an error detection device is shown.

[0054] In the accompanying drawings, elements with the same function are given the same reference numerals. Detailed Implementation

[0055] Figure 1An exemplary embodiment of a medical instrument 1 is schematically illustrated, which is purely exemplary configured as a magnetic resonance imaging (MRI) system. Thus, the illustrated medical instrument 1 includes an MRI scanner 2 and a data processing system 3 for controlling the MRI scanner 2. The medical instrument 1 also includes a computing unit 4 coupled to the data processing system 3 and / or the MRI scanner 2. Alternatively, the computing unit 4 may also include the data processing system 3, or vice versa. Other designs of the medical instrument 1 are possible, such as a computed tomography (CT) scanner.

[0056] For operation of the medical instrument 1, a screen 5 may be provided, which may be configured as, for example, a touch sensor device 7 or may include such a touch sensor device. Therefore, the operating surface 6 of the screen 5 may be configured to treat touching the operating surface and / or pressing and / or applying force to the operating surface 6 as an operation event 10 of the user of the medical instrument 1 (see [link to relevant documentation]). Figure 2 The attached figure (10) is used for detection.

[0057] Figure 2 Components of a touch sensor device 7 are shown. The touch sensor device 7 includes, for example, a touch sensor 8. Furthermore, the touch sensor device includes a control unit 9 configured to detect an operation event 10 at or on the operating surface 6 of the touch sensor device 7 by evaluating sensor data from the touch sensor 8. This operation event is performed, for example, by means of a user's hand 11 and fingers. Additionally, the touch sensor device 7 has an error detection device 12 configured to detect errors involving the control unit 9. The control unit 9 and / or the error detection device 12 are included, for example, by a data processing system 3 and / or a computing unit 4, or are provided in addition to said data processing system or computing unit.

[0058] exist Figure 2 The following details feature (a) of the touch sensor device 7, which relates to the following situation: an error in the control unit 9 is caused by common-mode interference. According to feature (a), the error detection device 12 is configured to directly measure the common-mode interference by detecting the voltage generated between a first reference potential at the ground terminal 13 of the reference control unit 9 and a second reference potential at the ground terminal 14 of the isolation power supply unit 15 of the reference touch sensor device 7.

[0059] The error detection device 12 may have at least one capacitor 16 and a voltage drop unit 17. The capacitor 16 is disposed between the voltage drop unit 17 and the isolation power supply unit 15, which can be understood, for example, as a measuring impedance. For example, the capacitor 16 may be disposed between the isolation element 23 that isolates the touch sensor device 7 from the power supply unit 15 and the power supply unit 15 that is electrically isolated from the remaining touch sensor device 7 through the isolation element 23, i.e., a ground connection, via a ground connection 21.

[0060] Furthermore, the error detection device 12 may include a voltage detection unit 18 configured to detect the voltage generated at the voltage drop unit 17. Additionally, the error detection device 12 may include an evaluation unit 19 configured to evaluate the voltage detected by means of the voltage detection unit 18. The evaluation unit 19, for example, is configured to check whether the detected voltage exceeds a preset voltage limit value when evaluating the voltage. If the voltage exceeds the preset voltage limit value, a trigger signal 20 may be provided for at least one of the following measures:

[0061] - The touch sensor 8 is used to determine the frequency used for the operation event 10, such that the frequency used is different from the frequency of the detected voltage that is above a preset voltage limit.

[0062] - Ignore the determined operation event 10 as long as the detected voltage is higher than the preset voltage limit;

[0063] - Disable and / or pause the distance mode, in which operation events 10 performed at intervals from the operation surface 6 can be detected;

[0064] - Disable and / or pause glove mode, in which operation events 10 performed while wearing gloves can be detected;

[0065] - Output a notification, for example, on the operating surface 6, indicating an error caused by common-mode interference; and / or

[0066] - Activate at least one method to reduce interference, especially spread spectrum.

[0067] At least one or more of the measures mentioned may be based on the premise that the touch sensor 8 and the control unit 9 are configured for capacitively determining the operation event 10, and not for resistively determining the operation event 10 and / or determining the operation event 10 by evaluating the user's force input.

[0068] The first reference potential can be understood as the local ground terminal 13 of the reference control unit 9. The first reference potential is provided via a ground connection 21 between the power supply unit 22 of the touch sensor device 7 and the control unit 9, as also illustrated herein. Here, reference numeral 20 is also used to illustrate that the trigger signal 20 can be transmitted from the evaluation unit 19 to the control unit 9 so that the control unit 9 can perform actions.

[0069] The power supply line 24 is also shown, and the energy supply unit 22 can supply energy to the control unit 9, for example, via the power supply line.

[0070] The touch sensor device 7 may have an intermediate component, which may be disposed between the control unit 9 and the isolation power supply 15. Thus, the error detection device 12 may, for example, detect the voltage generated between a first reference potential and a third reference potential at the ground terminal of the reference intermediate component. Typically, the third reference potential is less strongly coupled to the ground potential compared to a second reference potential at the ground terminal 14 of the reference isolation power supply 15.

[0071] It can be proposed that feature (a) be set only when the touch sensor 8 and control unit 9 are configured for capacitive determination of operation event 10. Alternatively or additionally, feature (a) may also be set when the touch sensor 8 and control unit 9 are configured for resistive determination of operation event 10 and / or when operation event 10 is determined by evaluating the user's force input.

[0072] Figure 3 Feature (b) of the touch sensor device 7 is shown in detail. Feature (b) is configured for situations where an error involving the control unit 9 is caused by a fault in the control unit 9. According to feature (b), the error detection device 12 is configured to: generate an AC voltage signal 30; apply the generated AC voltage signal 30 to the touch sensor 8 through the isolation region 31 of the touch sensor device 7; detect the effect of the applied AC voltage signal 30 caused by the operation event 10; and check whether the operation event 10 can be detected by the error detection device 12 but not by the control unit 9. If, for example, only the error detection device 12 detects the operation event 10, but the control unit 9 does not detect the operation event 10, a fault in the control unit 9 is identified.

[0073] In conjunction with feature (b), the error detection device 12 may include another control unit 32 configured to generate an AC voltage signal 30. The AC voltage signal 30 is referenced, for example, to the ground terminal 33 of the other control unit 32, particularly to the earth potential. Here, the ground terminal 13 of the control unit 9 also illustrates how the AC voltage signal 30 can pass through the isolation region 31, for example, to the ground connection 21 between the isolation element 23 and the power supply unit 22. Alternatively, a [further details are needed]. Figure 2 The grounding connection 21 between the energy supply unit 22 and the control unit 9 is shown in the diagram.

[0074] In a preferred example, another control unit 32 is configured for capacitively determining the operation event 10. However, in this example, the touch sensor 8 and the control unit 9 are configured for resistively determining the operation event 10.

[0075] In one example, at least one capacitor 16 may be disposed between another control unit 32 and the isolation region 31. The error detection device 12 may include the capacitor 16. The error detection device 12 is configured, for example, to detect the effect of the applied AC voltage signal 30 caused by the operation event 10 based on an increase in current in at least one capacitor 16. The error detection device 12 is particularly configured to determine whether the current increase detected at the capacitor 16 is greater than a preset current increase limit. The operation event 10 is considered detected only if, in particular, the detected current increase is greater than the preset current increase limit. Furthermore, the error detection device 12 may be configured to, particularly when the control unit 9 and the touch sensor 8 are configured for multi-touch detection, spread the AC voltage signal 30 to a frequency range having a preset minimum bandwidth by means of spread spectrum.

[0076] In addition, Figure 3 The following special case is illustrated: In addition to another control unit 32, the touch sensor device 7 also has a first control unit 34 for the first touch sensor 35 and a second control unit 36 ​​for the second touch sensor 37. The first touch sensor 35, together with the first control unit 34, is configured, for example, for capacitive detection of the operation event 10, particularly for multi-touch detection. The second touch sensor 37, together with the second control unit 36, is configured, for example, for detecting force input to detect the operation event 10, or for resistive detection of the operation event 10. In this example, the error detection device 12 is at least configured to identify faults in the second control unit 36. Alternatively, it may be proposed to identify faults in the first control unit 34. However, in a preferred example, only faults in the second control unit 36 ​​are identified and considered.

[0077] The operating surface 6 may have at least one first sub-region 38 and at least one second sub-region 39 different from the first sub-region 38, thereby dividing it into the first sub-region 38 and the second sub-region 39. The touch sensor device 7 may be configured to detect the operation event 10 in at least one first sub-region 38 by means of a first touch sensor 35 and a first control unit 34, and in at least one second sub-region 39 by means of a second touch sensor 37 and a second control unit 36. At least the second sub-region 39 may be configured for the operation event 10, which relates to at least one safety-related function of the medical instrument 1, for which the touch sensor device 7 determines the operation event 10 for the medical instrument.

[0078] Here, a second sub-region 39 with partial boundaries is drawn purely exemplarily, in which the user must press against the operating surface 6 in order to perform an operation. Conversely, the area surrounding the operating surface 6, which is associated with the first sub-region 38, can be operated by touch, such as by clicking, swiping, and / or other types of touch actions and / or touch gestures.

[0079] It can be proposed that the touch sensor device 7 includes, for example, two error detection devices 12, more specifically, one error detection device according to feature (a) and another error detection device according to feature (b), or a common error detection device 12 includes not only the component for feature (a) but also the component for feature (b).

[0080] Overall, this example demonstrates an improvement in interference suppression for a capacitive touchscreen, specifically a touch sensor device 7 used for capacitive detection of operational events 10.

[0081] Feature (a) is fully utilized based on the ability to directly measure common-mode interference (i.e., Gleichtaktstörungen). Since common-mode interference is the potential difference between the capacitance measurement circuit (given here, for example, as a control unit 9 with touch sensor 8) and the aforementioned wiring or ground potential, current can flow through an additional measurement path from the measurement circuit to the previous potential, and the common-mode interference is obtained by measuring only this current. Here, the measurement is performed by means of an error detection device 12. The construction of the error detection device includes the following extensions compared to a typical touch sensor device 7:

[0082] - Extended by at least one Y capacitor or another capacitor 16, which may be connected in parallel with the transformer in a manner permissible by safety technology;

[0083] - Extended by measuring impedance, which is connected on one side to the ground connection 21 of the capacitor circuit (i.e., sensor unit 9) and on the other side to the capacitor 16;

[0084] - Extended by measurement and analysis equipment (here, voltage detection unit 18 and evaluation unit 19), which detects the voltage generated at the measurement impedance and, for example, determines, through limit value analysis, which frequencies of the common-mode interference components are strong enough to potentially cause an error in the detected operating event 10.

[0085] In the next step, the measurement and analysis equipment transmits the analysis results to the controller, i.e., to the control unit 9. The controller should take different actions, i.e., different measures, based on the existing common-mode interference:

[0086] - Place the frequency used for capacitive identification on an unused frequency;

[0087] - In the event of sudden interference during touch input, ignore the recognition until the frequency is changed;

[0088] - Depending on the level of interference, functions such as spread spectrum technology can be activated or deactivated to suppress interference, which may have disadvantages in terms of operability, current consumption and other aspects.

[0089] - Under high interference levels, disable extended touch functionality, such as usability while wearing gloves or at a distance, where the extended touch functionality requires a particularly good signal-to-noise ratio;

[0090] - Use signals to convey to the user that strong interference exists and that the user should critically analyze their surroundings for possible sources of interference, i.e., output a warning notification.

[0091] Feature (b) is based on the capacitive wiring not being constructed separately on the electrically isolated section, but rather spanning the isolation section, i.e., through isolation region 31. In the capacitive touch electronics, an AC voltage is generated in a manner completely similar to the conventional construction, thereby generating an AC voltage signal 30 in another control unit 32. However, in the new construction, the AC voltage is referenced to the ground potential and applied to the ground potential of the resistive touch electronics via a Y safety capacitor ranging from 1 nanofarad to 10 nanofarads spanning the isolation section. Thus, the entire isolation circuit is continuously modulated at this potential. When a user touches the resistive touch sensor, the sensor's capacitance increases, thereby increasing the ground potential relative to the ground. This can be measured in the capacitive touch electronics by the increase in current from the AC voltage to the Y capacitor, i.e., capacitor 16. Therefore, the current transmitted by the AC voltage of the capacitive touch electronics is evaluated. Exceeding a certain current rise limit can be assessed as a user approaching.

[0092] Compared to existing electronic devices, the new architecture offers reduced complexity and improved functionality by eliminating the need for time-series coordination between the capacitance and resistance measurement systems: according to feature (b), both measurement systems can be always on. The signal-to-noise ratio in feature (b) is also better than that of existing solutions and less dependent on parasitic system effects.

[0093] In the case of a multi-touch capacitive input method using a force sensor and another redundant capacitive measurement method, the multi-touch input method can only be used for non-safety-related inputs, which may lead to malfunctions when conductive liquid is present on screen 5. Safety-related inputs are identified only by a force sensor that is insensitive to liquids, and as a redundancy measure, are determined by an additional capacitive measurement method that is also insensitive to liquids.

[0094] On the electronically isolated side, there is a capacitive multi-touch electronic device, here a first control unit 34 coupled to a capacitive touch sensor coupled to a user-touchable glass surface. There is also electronic device for a force sensor, here a second control unit 36, which may function differently. Importantly, this involves a pressure-activated sensor, positioned below the user-touchable glass surface, and capable of providing XY coordinates accurate to 1 cm to 2 cm and the applied force upon touch.

[0095] On the unisolated device side, there is a ground-referenced capacitive touch electronics device, i.e., another control unit 32. This capacitive touch electronics device cannot provide XY coordinates but only identifies whether there is a change in capacitance to ground caused by the user. In this application, the capacitive touch electronics device should be coordinated with the capacitive multi-touch electronics device, and only frequencies not used by the capacitive multi-touch electronics device are allowed for its AC voltage measurement, as interference effects may otherwise occur. In a preferred example, the signal is extended to a wide frequency range using spread band technology, so that the signal can work with any multi-touch electronics device. The ground-referenced capacitive touch electronics device also uses the capacitive touch sensor as the sensor surface by connecting the isolation portion via a Y capacitor.

[0096] The graphical user interface, i.e., the operating surface 6, can be divided into at least one non-security-related area and one security-related area, referred to herein as two sub-areas 38 and 39. The two sub-areas can be side-by-side, but nesting or division into multiple corresponding areas is also possible.

[0097] Each of the three mounted sensors detects the entire screen individually. However, the touch signal from the capacitive multi-touch sensor is only evaluated for non-safety-related areas. The signals from the force sensor and the grounded capacitive sensing device are used only for safety-related areas. Only a small number of graphic elements are placed in the safety-related areas because known force sensors only provide a resolution of 1 to 2 centimeters. Therefore, only the small, centered facet of each element is defined as the desired area, and the elements are placed far enough apart from each other and far enough away from non-safety-related areas to eliminate erroneous operations due to tolerance effects.

[0098] In other words, the present invention relates to a touch sensor device 7 for a medical instrument 1, the touch sensor device 7 comprising: a touch sensor 8, a control unit 9, the control unit 9 being configured to detect an operation event 10 at an operating surface 6 of the touch sensor device 7 by evaluating sensor data from the touch sensor 8, and including an error detection device 12 for detecting errors involving the control unit 9. The error detection device 12 is configured to:

[0099] (a) If the error is caused by common-mode interference, then measure the common-mode interference directly; and / or,

[0100] (b) If the error is caused by a fault in the control unit 9, an AC voltage signal 30 is generated and applied to the touch sensor 8 to detect the effect caused by the operation event 10, and to check whether the operation event 10 can be detected by means of the error detection device 12 but not by means of the control unit 9, wherein if this is the case, the fault in the control unit 9 is identified.

Claims

1. A touch sensor device (7) for use in a medical instrument (1), comprising: - Touch sensor (8) - A control unit (9) configured to detect an operation event (10) at the operating surface (6) of the touch sensor device (7) by evaluating sensor data from the touch sensor (8), and - Error detection device (12) for detecting errors involving the control unit (9). The error detection device (12) is configured to: (a) If the error is caused by common-mode interference, the common-mode interference is measured directly by detecting the voltage generated between a first reference potential at the ground terminal (13) of the control unit (9) and a second reference potential at the ground terminal (14) of the isolation power supply (15) of the touch sensor device (7); and / or, (b) If the error is caused by a fault in the control unit (9), an AC voltage signal (30) is generated and applied to the touch sensor (8) through the isolation area (31) of the touch sensor device (7). The effect of the applied AC voltage signal (30) caused by the operation event (10) is detected, and it is checked whether the operation event (10) can be detected by means of the error detection device (12) but not by means of the control unit (9). If this is the case, a fault in the control unit (9) is identified.

2. The touch sensor device (7) according to claim 1 and feature (a), wherein the error detection device (12) comprises at least one capacitor (16), a voltage detection unit (18) and an evaluation unit (19), the at least one capacitor (16) being disposed between a voltage drop unit (17) of the error detection device (12) and the isolation power supply unit (15), the voltage detection unit (18) being configured to detect a voltage generated at the voltage drop unit (17), and the evaluation unit (19) being configured to evaluate the voltage detected by means of the voltage detection unit (18).

3. The touch sensor device (7) according to claim 2, wherein the evaluation unit (19) is configured to check whether the detected voltage is higher than a preset voltage limit when evaluating the detected voltage, and if the detected voltage is higher than the preset voltage limit, to provide a trigger signal (20) for at least one of the following measures: - Change the frequency used by the touch sensor (8) to determine the operation event (10) so that the frequency used is different from the frequency associated with the detected voltage, which is higher than the preset voltage limit value; - Ignore the determined operation event (10) as long as the detected voltage is higher than the preset voltage limit value. - Disable and / or pause the distance mode, in which the operation events (10) performed at intervals from the operation surface (6) can be detected. - Disable and / or pause glove mode, in which operation events performed while wearing gloves can be detected (10). - Output a notification indicating an error caused by the common-mode interference; and / or - Activate at least one method to reduce interference, especially spread spectrum.

4. The touch sensor device (7) according to claim 2 or 3, wherein the touch sensor device (7) has at least one intermediate component disposed between the control unit (9) and the isolation power supply (15), wherein the error detection device (12) is configured to detect a voltage generated between the first reference potential and a third reference potential referencing the ground terminal of the intermediate component as the common-mode interference, wherein the third reference potential is less strongly coupled to the ground potential compared to the second reference potential.

5. The touch sensor device (7) according to any one of the preceding claims and feature (a) of claim 1, wherein the first reference potential is referenced to a local ground terminal (13) of the control unit (9), the local ground terminal (13) being provided via a ground terminal connection (21) between the power supply unit (22) of the touch sensor device (7) and the control unit (9).

6. The touch sensor device (7) according to any one of the preceding claims and feature (b) of claim 1, wherein the error detection device (12) includes another control unit (32) configured to generate the AC voltage signal (30), wherein the AC voltage signal (30) is preset with reference to the ground terminal (33) of the other control unit (32).

7. The touch sensor device (7) according to claim 6, wherein the other control unit (32) is configured to capacitively determine the operation event (10), while the touch sensor (8) and the control unit (9) are configured to resistively determine the operation event (10).

8. The touch sensor device (7) according to claim 6 or 7, wherein at least one capacitor (16) of the error detection device (12) is provided between the other control unit (32) and the isolation area (31) of the touch sensor device (7), and the error detection device (12) is configured to detect the effect of the applied AC voltage signal (30) caused by the operation event (10) by means of an increase in current in the at least one capacitor (16).

9. The touch sensor device (7) according to claim 8, wherein the error detection device (12) is configured to determine whether the detected current rise is greater than a preset current rise limit, and if the detected current rise is greater than the preset current rise limit, then the operation event (10) itself is detected.

10. The touch sensor device (7) according to any one of the preceding claims and feature (b) of claim 1, wherein the error detection device (12) is configured to spread the AC voltage signal (30) over a frequency range (31) having a preset minimum frequency range width by means of spread spectrum.

11. The touch sensor device (7) according to any one of the preceding claims and feature (b) of claim 1, wherein the touch sensor device (7) has a first touch sensor (35) with a first control unit (34) and a second touch sensor (37) with a second control unit (36), the first control unit (34) being configured to capacitively detect the operation event (10), the second control unit (36) being configured to resistively detect the operation event (10) and / or to determine the operation event based on force input (11), and the error detection device (12) being configured to identify at least one fault in the second control unit (36).

12. The touch sensor device (7) according to claim 11, wherein the operating surface (6) is divided into at least one first sub-region (38) and at least one second sub-region (39), and the touch sensor device (7) is configured to detect the operation event (10) in the at least one first sub-region (38) by means of the first touch sensor (35) and the first control unit (34), and to detect the operation event (10) in the at least one second sub-region (39) by means of the second touch sensor (37) and the second control unit (36).

13. The touch sensor device (7) according to claim 12, wherein the at least one second sub-region (39) is configured for an operation event (10) relating to a safety-related function of the medical instrument (1), the operation event (10) being determined by means of the touch sensor device (7) for the medical instrument.

14. A medical instrument (1) having a touch sensor device (7) according to any one of the preceding claims.

15. A method for operating a touch sensor device (7) for a medical instrument (1), the touch sensor device comprising: - Touch sensor (8) - Control unit (9), by means of the control unit, detects an operation event (10) at the operating surface (6) of the touch sensor device (7) by evaluating the sensor data of the touch sensor (8), and - Error detection device (12) for detecting errors involving the control unit (9). Among them, the error detection device (12): (a) If the error is caused by common-mode interference, the common-mode interference is measured directly by detecting the voltage generated between a first reference potential at the ground terminal (13) of the control unit (9) and a second reference potential at the ground terminal (14) of the isolation power supply (15) of the touch sensor device (7); and / or, (b) If the error is caused by a fault in the control unit (9), an AC voltage signal (30) is generated and applied to the touch sensor (8) through the isolation area (31) of the touch sensor device (7). The effect of the applied AC voltage signal (30) caused by the operation event (10) is detected, and it is checked whether the operation event (10) is detected by means of the error detection device (12) but not by means of the control unit (9). If this is the case, a fault in the control unit (9) is identified.

Images