Patent ID: 12194262

DETAILED DESCRIPTION

FIG.1schematically shows a balloon dilation device100having a balloon102and a sensor coil (not shown) arranged at the distal end106of the balloon dilation device100.

The balloon dilation device100can be used for dilating a sinus cavity and a Eustachian tube.

The balloon dilation device100comprises a shaft108, the shaft108comprising a hypo tube110. The hypo tube110can be made of, e.g., polytetrafluoroethylene (PTFE), steel, or nitinol. The hypo tube110has an outer diameter of 1.4 mm. In various other embodiments that are not shown the balloon dilation device is realised with a hypo tube having an outer diameter of between 1.2 mm and 1.5 mm. The hypo tube110has a central lumen (not visible) having a diameter of 0.8 mm thus constituting an inner diameter of the hypo tube. In various other embodiments that are not shown the balloon dilation device is realised with a hypo tube having an inner diameter of between 0.7 mm and 1.0 mm. Alternatively, the shaft can be realized without a central lumen and with the at least one sensor coil, e.g., being embedded into or attached to the shaft, preferably, at or close to the distal end of the balloon dilation device. Alternatively, the shaft of the balloon dilation device100can be configured the same way as the shafts being described with respect toFIGS.6,7,8, and9, thus, having an inner and an outer hypo tube.

The hypo tube110is attached to a handle112, the handle extending from the proximal end114of the balloon dilation device100towards the distal end106of the balloon dilation device100. The central lumen extends through the handle112to an attachment116for inserting, e.g., a marker carrier (equipped with one or more sensor coils), a light fibre or a suction tube. The handle112has a length L1of 130 mm and a diameter D1of 19 mm.

The handle112comprises an attachment118for attaching a fluid source (not shown) to the balloon dilation device, e.g., via a tube. From the attachment118, an inflation lumen (not visible) extends through the handle112and the shaft108to a connecting point (not visible) for feeding a fluid into or out of a balloon102that is arranged adjacent to the distal end106of the balloon dilation device100. The balloon102can be inflated by feeding a fluid through the inflation lumen into the balloon102. Respectively, the balloon102can be deflated by feeding a fluid out of the balloon102through the inflation lumen.

When being inflated, the balloon has a diameter D2of 6 mm. In other embodiments that are not shown the diameter of the balloon in its inflated state can be different, e.g., the diameter can lie between 3 mm and 10 mm. The balloon102is fixedly arranged at the shaft108and has a length L2of 18 mm. In various embodiments, however, the balloon can have a different length that, e.g., is between 10 mm and 25 mm, preferably, between 15 mm and 20 mm.

The shaft108has a length L3of 128 mm. Extending from the distal end106of the balloon dilation device100towards the proximal end114of the balloon dilation device100, the shaft108comprises a malleable tip region122having a length L4of 30 mm. Preferably, the malleable tip region122of the shaft108is produced by heat treatment of the shaft108.

A balloon dilation device having a shaft with a length of 128 mm can also have a malleable tip region having different length, e.g., a length that is between 10 mm and 60 mm, preferably between 20 mm and 50 mm, even more preferably between 25 mm and 35 mm. The balloon dilation device can also have a shaft having a different length, e.g., a length of between 1.2 mm and 1.8 mm, preferably between 1.2 mm and 1.6 mm, even more preferably between 1.2 mm and 1.4 mm. A balloon dilation device having a shaft with a length of between 1.2 mm and 1.8 mm can also have a malleable tip region extending from the distal end of the balloon dilation device towards the proximal end of the balloon dilation device, the malleable tip region having a length that is between 10 mm and 60 mm.

Since the balloon dilation device100is equipped with the sensor coil, position and orientation of the balloon dilation device100can be determined with a position detection system (not shown). In particular, position and orientation of the balloon dilation device100can be calculated using a determined position and orientation of the sensor coil. Therefore, the balloon dilation device100is exposed to an alternating electromagnetic field such that a current is induced in the sensor coil. The current induced depends on position and orientation of the sensor coil in relation to the alternating electromagnetic field. When a current is induced, a sensor coil signal is transmitted from the sensor coil to the position detection system, e.g., via a cable connecting the sensor coil to the position detection system. The sensor coil signal can be processed by the position detection system to determine position and orientation of the sensor coil. Having calculated position and orientation of the balloon dilation device based on the determined position and orientation of the sensor coil, the position of the balloon dilation device can be displayed in images of a patient for supporting a surgeon in navigating the balloon dilation device inside a human body.

FIG.2schematically shows a balloon dilation device200in a longitudinal sectional view with a marker carrier202, the marker carrier202comprising two sensor coils204,206that are displaced in longitudinal direction along the shaft208.

The marker carrier202is arranged in a central lumen210, the central lumen210extending from the distal end212of the balloon dilation device200to the proximal end214of the balloon dilation device200. The marker carrier202extends through the full length of the central lumen210and can be removed from the lumen through an opening216at the proximal end214of the balloon dilation device200, e.g., after having positioned the balloon dilation device200, e.g., in a sinus cavity. Because the central lumen210also has an opening218at the distal end of the balloon dilation device200, after removing the marker carrier202the central lumen210can be used for suction or irrigation purposes. For example, after removing the marker carrier202from the central lumen a suction tube can be inserted into the central lumen210for drainage of mucus from the paranasal sinuses. The central lumen210extends through the shaft208and through the handle220from the distal end212of the balloon dilation device200to the proximal end214of the balloon dilation device200. By way of example, the shaft can comprise one hypo tube as described with reference toFIG.1or can have an inner and an outer hypo tube as described with reference toFIG.5,6,7,8, or9.

Furthermore, an inflation lumen (not shown) extends from the proximal end214of the balloon dilation device200to a connecting point (not shown). At the connecting point the inflation lumen is fluidly connected to a balloon222that is arranged at the shaft208. Through the inflation lumen a fluid can be fed into or out of the balloon for inflating and deflating the balloon222, respectively.

The balloon222is arranged within a malleable tip region224of the shaft208. In the malleable tip region, the shaft can be plastically deformed to facilitate accessing passageways and positioning of the balloon dilation device200, e.g., in sinus cavities.

The first sensor coil204is arranged at the distal end212of the balloon dilation device200such that when the shaft is plastically deformed in the malleable tip region224, e.g., using a shaping tool, the sensor coil204is displaced with respect to the rest of the shaft.

The second sensor coil206is arranged at the shaft but adjacent to the malleable tip region224. Hence, if the shaft208is bend in the malleable tip region224, the second sensor coil206is not displaced with respect to the rest of the shaft208. Position and orientation of the second sensor coil thus represent position and orientation of the part of the shaft that stays unbend. However, when plastically deforming the shaft in the malleable tip region224, the first204sensor coil is displaced with respect to the second sensor coil206such that the two sensor coils204,206have a non-zero angle enclosed between their longitudinal axis.

By determining position and orientation of the first and second sensor coils204,206, the degree of bending of the shaft208can be calculated from the determined position and orientation of each of the two sensor coils204,206. In particular, the shape of the balloon dilation device in that section of the shaft that lies between the two sensor coils204,206can be reconstructed based on the determined position and orientation of each of the two sensor coils204,206. Using the reconstructed shape of the balloon dilation device, the balloon dilation device200can be visualized on monitor in its actual shape thus having a bend malleable tip region224.

This is of advantage since a surgeon can decide more reliably when to inflate or deflate the balloon222inside a sinus cavity based on the actual position and shape of the balloon dilation device200positioned inside, e.g., a sinus cavity.

FIG.3schematically shows a medical system300comprising a balloon dilation device302, the balloon dilation device302comprising a sensor coil304and a balloon306.

The balloon dilation device302can be configured the same way as the balloon dilation device described with reference toFIG.1or the balloon dilation device described with reference toFIG.2or the balloon dilation device as described with reference toFIG.5.

The balloon dilation device302is connected to a fluid source308via a tube. The fluid source is configured for providing a fluid, i.e., a gas or a liquid. For inflating the balloon306, a fluid is fed into the balloon306. The fluid source308comprises an optional fluid sensor310for measuring a physical quantity of a fluid that is fed into the balloon. The fluid sensor can be an inflation pressure sensor for measuring an inflation pressure or a fluid volume sensor for measuring an amount of fluid that has been fed into or out of the balloon. Also both sensors can be present at the same time. Additionally or alternatively to one or more fluid sensors comprised by the fluid source, the balloon dilation device itself can have one or more fluid sensors. These fluid sensor of the balloon dilation device can likewise be an inflation pressure sensor or a fluid volume sensor. The balloon dilation device can also comprise a sensor that is configured for directly detecting the shape of the balloon. Fluid sensor310of the fluid source308and, if present, fluid sensors comprised by the balloon dilation device302itself are configured for providing fluid sensor signals representing the measured a physical quantity of the fluid.

Fluid sensor signals representing a measured physical quantity of the fluid can be transmitted to a balloon shape computation unit312, e.g., via a cable or wireless. The balloon shape computation unit312is configured for computing the shape of the balloon306based on fluid sensor signals provided by the fluid sensor310of the fluid source308. If no fluid sensor310for measuring a physical quantity of the fluid is present in the medical system300, also no balloon shape computation unit312needs to be present which is thus an optional element.

The balloon shape computation unit312is connected to a visualization unit314, the visualization unit314, preferably, being configured to access and use the computed balloon shape. Thus, the visualization unit314is configured to process the computed balloon shape, in particular, for visualizing the balloon dilation device302having a balloon shape as computed by the balloon shape computation unit308on a monitor316.

The medical system300comprises a position detection system318for determining position and orientation of the balloon dilation device302based on sensor coil signals provided by the sensor coil304Preferably, the sensor coil304is arranged at the shaft of the balloon dilation device302at the distal end of the balloon dilation device302. The position detection system318can comprise a field generator (not shown) for generating an alternating electromagnetic field. For determining position and orientation of the balloon dilation device302, the balloon dilation device302equipped with the sensor coil304is exposed to the alternating electromagnetic field such that a current is induced in the sensor coil304. When a current is induced, respective a sensor coil signal can be transmitted to the position detection system318, e.g., via a cable or wirelessly. The position detection system318is configured for processing a received sensor coil signal for calculating position and orientation of the balloon dilation device302. This often includes that position and orientation represented by the sensor coil signal are determined and used together with transformation functions obtained by calibrating the sensor coil to the tip of the balloon dilation device302to calculate position and orientation of the balloon dilation device302relative to the position detections system318.

The position detection system318is connected to the visualization unit314. The visualization unit314is configured for visualizing a digital representation of at least a part of the balloon dilation device302, e.g., the balloon dilation device tip, on the monitor316based on the position and orientation of the balloon dilation device302as determined by the position detection system318. Preferably, a digital representation of the balloon dilation device302is visualized together with images of a patient to support a surgeon in handling the balloon dilation device302while guiding the balloon dilation device302inside the human body.

In particular, if the balloon dilation device302comprises several sensor coils, preferably, at least two sensor coils, arranged at and distributed along the length of the shaft of the balloon dilation device302, the medical system can comprise an optional device shape reconstruction unit320. The device shape reconstruction unit320is connected to the position detection system318and to the visualization unit314. The device shape reconstruction unit320is configured for reconstructing the shape of the balloon dilation device302based on position and orientation of the sensor coil304determined by the position detection system318. In particular, the device shape reconstruction unit320is configured for accessing the determined position and orientation for each sensor coil present in the balloon dilation device302and to process the determined positions and orientations of the sensor coils for reconstructing the shape of the balloon dilation device302.

Preferably, if a device shape reconstruction unit320is present, the visualization unit314is configured for visualizing the balloon dilation device302in its reconstructed shape. In particular, the shape of the balloon dilation device can be reconstructed taking into account a possible bending of the shaft in its malleable tip region.

FIG.4shows a flow diagram representing a method for determining position and orientation of a balloon dilation device. The method described in the following can be implemented using a medical system as described with reference toFIG.3.

The method comprises the steps of

generating an electromagnetic field S1,

exposing the balloon dilation device to the electromagnetic field, the balloon dilation device having an inflatable balloon and at least one sensor coil S2,

detecting position and orientation of the at least one sensor coil S3,

determining position and orientation of the balloon dilation device based on the detected position and orientation of the at least one sensor coil S4, and

visualizing a digital representation of at least a part of the balloon dilation device on a monitor based on the determined position and orientation of the balloon dilation device S5.

FIG.5shows a balloon dilation device500comprising a balloon502, a shaft504, a handle506and at least one sensor coil (not shown).

The shaft504extends from the distal end508of the balloon dilation device500towards the proximal end510of the balloon dilation device500and has an inflation lumen (not visible). The shaft504comprises an inner hypo tube512and an outer hypo tube514. The inner hypo tube512has an outer diameter that is equal to or smaller than the diameter of a lumen of the outer hypo tube514. The inner hypo tube512is at least partly arranged inside the lumen of the outer hypo tube514. At least with the outer hypo tube514, the shaft504is attached to the handle506. The outer hypo tube514does not extend up to the distal end508of the balloon dilation device500but ends before. The inner hypo tube512extends up to the distal end508of the balloon dilation device500. The total length of the shaft504thus is the sum of the lengths of the visible part of the outer hypo tube514and the visible part of the inner hypo tube512.

The inner hypo tube512is completely annealed such that it has an ultimate tensile strength of up to 750 N/mm2. That part of the inner hypo tube512that extends between the distal end508of the balloon dilation device500and the distal end of the outer hypo tube514, i.e., the visible part of the inner hypo tube512, forms a malleable tip region516of the shaft.

In the malleable tip region516the inflatable balloon502is fixedly arranged at the shaft504, i.e., attached to the inner hypo tube512of the shaft504. The balloon502has a length that is approximately equal to the length of the malleable tip region516. Thereby, when plastically deforming the shaft504in the malleable the region516, the balloon502itself also deforms accordingly. In particular, if the malleable tip region516is formed to have an angle, typically, the balloon502, too, shows a corresponding bend.

The balloon502is fluidly connected to the inflation lumen of the balloon dilation device500such that the balloon502can be inflated and deflated by feeding a fluid through the inflation lumen into or out of the balloon502. The fluid for inflating the balloon502can be provided by a fluid source (not shown) that is connect to the inflation lumen, e.g., via a tube, at the attachment518arranged at the handle506. The inflation lumen thus extends from the attachment518through the handle506and the shaft504to a connecting point (not visible) for feeding a fluid into or out of a balloon502.

The balloon dilation device500comprises a central lumen (not visible). The central lumen extends from an opening of the inner hypo tube512at the distal end508of the balloon dilation device500to an attachment520that is arranged at the handle506. Alternatively, the central lumen can extend from the attachment520through the handle506and the shaft and end before the distal end508of the balloon dilation device500. In that embodiment the shaft can be closed at the distal end508of the balloon dilation device500, i.e., in this case no opening is present at the distal end508of the balloon dilation device500.

In the central lumen at least one sensor coil (not shown) is arranged that is configured for capturing an electromagnetic field and for providing a sensor coil signal representing position and orientation of the sensor coil. By means of the at least one sensor coil, the balloon dilation device500can be connected to a position detection system that is configured for determining position and orientation of the balloon dilation device500in an electromagnetic field.

The at least one sensor coil can also be comprised in a marker carrier that is arranged inside the central lumen of the balloon dilation device500. In particular, through the attachment520, a marker carrier comprising, e.g., two sensor coils can be inserted into the central lumen to be removably arranged inside the central lumen.

If a marker carrier comprises at least one sensor coil that is configured for capturing an electromagnetic field, position and orientation of the sensor coil can be determined with an electromagnetic position detection system. In particular, the at least one sensor coil of a marker carrier can be used to connect the balloon dilation device500to a position detection system in order to track the position of the balloon dilation device500. By connecting the balloon dilation device500to a position detection system, it is possible to display the position of the balloon dilation device500in sectional images of a model of a patient in order to assist a surgeon in navigating the balloon dilation device500. Since the marker carrier can be arranged removably inside the central lumen, after having positioned the balloon dilation device500in a cavity, the marker carrier can be removed from the central lumen and, e g., a suction tube can be inserted into the central lumen.

If a marker carrier comprising sensor coils is arranged inside the central lumen, preferably, one sensor coil is arranged at the distal end508of the at least balloon dilation device500and a second coil is arranged adjacent to the malleable tip region516, i.e., in that part of the shaft504in which the outer hypo tube514is present. Preferably, the sensor coils of the marker carrier are arranged inside the central lumen such that, if the malleable tip region of the shaft is deformed plastically, a non-zero angle is enclosed between the longitudinal axis of the two coils. From the determined position and orientation of the two sensor coils with respect to each other, it is possible to determine a bending of the shaft504, in particular, in the malleable tip region516and to reconstruct the shape of the balloon dilation device500having a shaft with a plastically deformed malleable tip region.

FIG.6shows a shaft600that has an inner hypo tube602and an outer hypo tube504. The shaft600can be attached to a handle (not shown) of a balloon dilation device, e.g., of a balloon dilation device as described with respect toFIG.1or of a balloon dilation device as described with respect toFIG.5.

The inner hypo tube602is completely annealed. The outer hypo tube604is configured such that it does not plastically deform if an external force of a magnitude typically acting on the shaft during surgery is exerted on the outer hypo tube604. The inner hypo tube602is at least partly arranged inside a lumen of the outer hypo tube604.

The outer hypo tube604ends before the distal end606of the shaft600. The inner hypo tube602extends up to the distal end606of the shaft600such that the shaft's total length is the sum of the visible parts of the inner hypo tube602and the outer hypo tube604.

That part of the inner hypo tube602that extends from the distal end of the outer hypo tube604to the distal end606of the shaft600forms a malleable tip region608of the shaft600. In particular, in the malleable tip region608, the shaft can be plastically deformed, e.g., using a shaping tool. It is preferred that prior surgery, the shaft in its malleable tip region608is plastically deformed so that the shape of the shaft is suitable for a specific procedure to be carried out with a balloon dilation device.

For example, for different procedures in the malleable tip region608the shaft600can be plastically deformed to have a specifically selected angle with respect to the rest of the shaft, i.e., with respect to the outer hypo tube604. For example, a shaping tool can be used having several pre-fixed shape positions that are suitable, e.g., for accessing a particular cavity.

Fixed to the shaft600in the malleable tip region608there is an inflatable balloon610. The balloon610has a length that corresponds to the length of the malleable tip region608. The balloon610is fluidly connected to the inflation lumen (not visible) of the shaft600such that the balloon610can be inflated and deflated by feeding a fluid through the inflation lumen into or out of the balloon600.

At the shaft600, at least one sensor coil (not visible) is arranged, the at least one sensor coil being configured for capturing an electromagnetic field and for providing a sensor coil signal representing position and orientation of the sensor coil in an electromagnetic field. For example, the shaft600can comprise two sensor coils that are arranged at the shaft600as described with reference toFIG.7.

InFIG.7, a shaft700is shown in a longitudinal sectional view, the shaft700having an inner hypo tube702and an outer hypo tube704that are arranged and configured as described with reference toFIG.6. Also as described with reference toFIG.6there is a balloon706fixedly arranged at the shaft700.

The shaft700has a central lumen708and an inflation lumen (not visible). In the central lumen708two sensor coils710,712are arranged. The first sensor coil710is arranged at the distal end714of the shaft700and the second sensor coil712is arranged adjacent to the malleable tip region716of the shaft700. If the malleable tip region716is plastically deformed to have an angle with respect to the rest of the shaft700, preferably, the two sensor coils are displaced such that their longitudinal axis enclose a non-zero angle.

Each of the sensor coils710,712is connected to electrical wiring (not shown) running from the respective sensor coil710,712towards a proximal end of the shaft700. Preferably, if the shaft700is attached to a handle of a balloon dilation device, the electrical wiring run up to an electrical connection of the balloon dilation device at which the electrical wiring can be connected to a cable for connecting the balloon dilation device to a position detection system. Via the electrical wiring, sensor coil signals provided by the sensor coils710,712can be transmitted to a position detection system that is configured for determining position and orientation of each of the sensor coils710,712by analysing respective sensor coil signals. Based on determined position and orientation of the two sensor coils it is possible to determine the bending of the shaft700and to reconstruct the actual shape of the shaft700in case the malleable tip region716of the shaft700is plastically shaped.

The sensor coils710,712can be part of a marker carrier that is removably arranged inside the central lumen708of the shaft700to connect a balloon dilation device to a position detection system.

It is also possible that the shaft comprises only one of the sensor coils710,712or additional sensor coils that are distributed along the length of the shaft.

InFIG.8, a shaft800is shown having a completely annealed inner hypo tube802and an outer hypo tube804. The outer hypo tube804is configured such that it does not plastically deform if an external force of a magnitude typically acting on the shaft800during surgery is exerted on the outer hypo tube804. The shaft800can be attached to a handle (not shown) of a balloon dilation device, e.g., of a balloon dilation device as described with reference toFIG.1or of a balloon dilation device as described with reference toFIG.5.

The inner hypo tube802is arranged at least partly in a lumen of the outer hypo tube804. The outer hypo tube804ends before the distal end806of the shaft800. The completely annealed inner hypo tube802extends up to the distal end806of the shaft800and that part of the inner hypo tube802that extends from the distal end of the outer hypo tube804to the distal end806of the shaft800forms the malleable tip region808of the shaft800.

In the malleable tip region808, a balloon810is fixedly arranged at the shaft800. The balloon810is fluidly connected to the inflation lumen (not visible) of the shaft800such that the balloon810can be inflated and deflated by feeding a fluid through the inflation lumen into or out of the balloon800.

The balloon810is arranged adjacent to the distal end806of the shaft and has a length that is smaller than the length of the malleable tip region. As a result, the proximal end of the balloon810ends before proximal end of the malleable tip region808such that there is an exposed section812of the inner hypo tube802in which no balloon810is arranged. Preferably, this exposed section812of the inner hypo tube802forms a bending section in which the malleable tip region808can be plastically deformed several times for shaping the malleable tip region808.

If the malleable tip region808is deformed in the exposed section812such that the malleable tip region808has an angle to the rest of the shaft800, i.e., to the outer hypo tube804, the remaining part of the malleable tip region808in which the balloon810is arranged can maintain its shape. Advantageously, thereby, the balloon810itself is not mechanically stressed by shaping the malleable tip region808and can maintain its balloon shape.

At the shaft800, at least one sensor coil (not visible) is arranged. For example, the shaft800can comprise two sensor coils that are arranged at the shaft800as described with reference toFIG.9.

FIG.9shows a shaft900in a longitudinal sectional view, the shaft900having a completely annealed inner hypo tube902and an outer hypo tube904that are arranged and configured as described with reference toFIG.8.

The shaft900has a central lumen906and an inflation lumen (not visible). In the central lumen906two sensor coils908,910are arranged such that a first coil908is arranged at the distal end912of the shaft900and a second coil910is arranged adjacent to the malleable tip region914. The two sensor coils908,910are connected to electrical wiring (not shown) for connecting the two sensor coils908,910to a position detection system. From sensor coil signals provided by the sensor coils908,910, position and orientation of each of the sensor coils can be determined with a connected position detection system.

In the malleable tip region914, a balloon916is fixedly arranged at the shaft900and fluidly connected to the inflation lumen such that the balloon916can be inflated and deflated by feeding a fluid through the inflation lumen into or out of the balloon916.

As described with reference toFIG.8, the balloon912is arranged adjacent to the distal end912of the shaft900and ends before the distal end of the outer hypo tube904. Thereby, a section918of the inner hypo tube902that extends between the proximal end of the balloon916and the proximal end of the malleable tip region914is exposed, i.e., is visible from outside. In particular, in the exposed section918, the shaft can be plastically deformed to shape the malleable tip region914to have an angle to the rest of the shaft900.