In a positioning system, a plurality of transmitter units (2, 3, 4, 5) transmit respective locating signals which are received at a mobile receiver unit (7). A processing system (7; 9) identifies the transmitter unit that transmitted each locating signal, and determines, for each transmitter unit, range data representative of a respective distance between the transmitter unit and the mobile receiver unit. The processing system determines a position estimate for the mobile receiver unit (7) by solving an optimisation problem that depends on i) the range data determined for the plurality of transmitter units, ii) data representative of the positions of the plurality of transmitter units in an environment (1), and iii) data representative of a position of a surface (1a, 1b, 1c, 1d, 1e; 601, 602) in the environment, by optimising for an objective function comprising a cost term that depends on a distance between the surface and the position estimate.

A device (10) is placed on an object (30). A reference feature of the object (30) is aligned with a reference feature of the device (10). Based on signals transmitted between at least one measurement point of the device (10) and a further device (20), a position of the at least one measurement point is measured. The position of the object (30) is then determined based on the measured position of the at least one measurement point and based on information on arrangement of the at least one measurement point in relation to the reference feature of the device (10).

A device (10) is placed on an object (30). A reference feature of the object (30) is aligned with a reference feature of the device (10). Based on signals transmitted between at least one measurement point of the device (10) and a further device (20), a position of the at least one measurement point is measured. The position of the object (30) is then determined based on the measured position of the at least one measurement point and based on information on arrangement of the at least one measurement point in relation to the reference feature of the device (10).

Methods and systems are disclosed for determining pose information for at least one of a transmitter and receiver, both of which comprise ultrasonic transducers. A relative position is determined between the transmitter and the receiver and an orientation for at least is also determined. After obtaining field of view data for at least one of the transmitter and receiver, a field of view between them is determined, based at least in part on the field of view data, the determined relative position and the determined orientation. The pose information is then determined by weighting measurements of an ultrasonic signal emitted by the transmitter and received by the receiver based at least in part on the determined field of view relationship.

The present invention provides a range-finding method, apparatus, system, and non-transitory computer-readable storage medium. The method includes: acquiring a predicted number of interrupts of a single-chip microcomputer; acquiring a to-be-measured signal; triggering a first output of a comparator according to a strength of the to-be-measured signal and a preset trigger threshold; recording an ultrasonic signal and acquiring an actual number of interrupts according to the first output; and adjusting the trigger threshold according to the predicted number of interrupts and the actual number of interrupts, where the adjusted trigger threshold is used to trigger the first output next time. The trigger threshold of the comparator can be adaptively adjusted according to the number of interrupts to adjust sensitivity of recording the ultrasonic signal, so as to adapt to different measurement environments and ranges, accurately record an arrival time of the ultrasonic signal, and improve the accuracy of a range-finding result.

Aspects of the subject technology relate to a system including a reference device, a measurement device and a processor. The measurement device provides a three-dimensional (3-D) point map corresponding to first positions of a plurality of selected points on a torso of a user. The processor determines a shape of the torso based on the 3-D point map. The measurement device is sequentially placed on the plurality of selected points, and the 3-D point map represents the first positions of the plurality of selected points relative to a second position associated with a location in 3-D space of the reference device.

Aspects of the subject technology relate to a system including a reference device, a measurement device and a processor. The measurement device provides a three-dimensional (3-D) point map corresponding to first positions of a plurality of selected points on a torso of a user. The processor determines a shape of the torso based on the 3-D point map. The measurement device is sequentially placed on the plurality of selected points, and the 3-D point map represents the first positions of the plurality of selected points relative to a second position associated with a location in 3-D space of the reference device.

A head mounted display device and a positioning device thereof are provided. The positioning device includes a first sensor, a second sensor, a third sensor, a first hinge sensor, and a controller. The first sensor and the second sensor have a fixed relative location. The third sensor is disposed on a first flexible member of the head mounted display device. The first hinge sensor is disposed on a first connecting portion configured to connect a main body portion and the first flexible member, wherein the first hinge sensor is configured to sense a first movement state of the first flexible member. The controller is configured to calculate a first relative location information of the first sensor, the second sensor, and the third sensor, and to calibrate the first relative location information according to the first movement state.

A head mounted display device and a positioning device thereof are provided. The positioning device includes a first sensor, a second sensor, a third sensor, a first hinge sensor, and a controller. The first sensor and the second sensor have a fixed relative location. The third sensor is disposed on a first flexible member of the head mounted display device. The first hinge sensor is disposed on a first connecting portion configured to connect a main body portion and the first flexible member, wherein the first hinge sensor is configured to sense a first movement state of the first flexible member. The controller is configured to calculate a first relative location information of the first sensor, the second sensor, and the third sensor, and to calibrate the first relative location information according to the first movement state.

The present invention relates to an apparatus for tracking a position of an interventional device respective an image plane of an ultrasound field. The position includes an out-of-plane distance (Dop). A geometry-providing unit (GPU) includes a plurality of transducer-to-distal-end lengths (Ltde.sub.1 . . . n), each length corresponding to a predetermined distance (Ltde) between a distal end of an interventional device and an ultrasound detector attached to the interventional device, for each of a plurality of interventional device types (T.sub.1 . . . n). An image fusion unit (IFU) receives data indicative of the type (T) of the interventional device being tracked; and based on the type (T): selects from the geometry-providing unit (GPU), a corresponding transducer-to-distal-end length (Ltde); and indicates in a reconstructed ultrasound image (RUI) both the out-of-plane distance (Dop) and the transducer-to-distal-end length (Ltde) for the interventional device within the ultrasound field.