Abstract:
A method of processing three-dimensional image data for volume-rendering from a viewpoint is described. Lower- and upper-bound-generating functions are used (7) to determine whether, across all possible values for the image voxels between respective lower and upper bounds, for each voxel (i) the voxel may be at least partially opaque under the opacity transfer function (8); and (ii) the voxel may be unoccluded from the viewpoint (9). A predetermined processing operation is then applied to these potentially-visible voxels, for which both determinations hold true (10) and the processed voxels may be rendered (1 1). The bound-generating functions and the processing operation are such that, for any three-dimensional image data, the value of a voxel after the processing operation will necessarily lie between the lower and upper bounds for that voxel.
Abstract:
An integrated-circuit radio communication device (1) comprises a processor (7) having a hardware-interrupt input line; memory (13); radio communication logic (17); and interrupt-interface logic (8). The memory (13) contains a firmware module (23) comprising (i) instructions (31) for controlling the radio communication logic (17) according to a predetermined radio protocol, and (ii) an interrupt routine comprising instructions for receiving an identification of a radio communication function in the firmware module (23) and for invoking the identified radio communication function. The interrupt-interface logic (8) comprises input logic for receiving a signal generated by software (27) executing on the device (1), and output logic arranged to assert the hardware-interrupt input line of the processor (7) in response to receiving a software-generated signal at the input logic. The device (1) is configured to invoke the interrupt routine in response to an assertion of the hardware-interrupt input line of the processor (7).
Abstract:
An integrated-circuit radio communication device (1) comprises a processor (7), memory (13), and radio communication logic (17). The memory (13) has a firmware module (23) stored at a firmware memory address, the firmware module (23) comprising instructions for controlling the radio communication logic (17) according to a predetermined radio protocol. The processor (7) is configured to receive supervisor call instructions, each having an associated supervisor call number, and to respond to a supervisor call instruction by (i) invoking a supervisor call handler in the firmware module (23), and (ii) making the supervisor call number available to the call handler. A software application (27) is loaded into the memory (13) of the device (1), and stored at a predetermined application memory address. It is arranged to invoke a radio communication function from the firmware module (23) by issuing a supervisor call instruction having an associated predetermined supervisor call number corresponding to the function to be invoked.
Abstract:
An assay cartridge has a base member (26) that defines at least two wells (30, 32, 34, 36, 38), a pipette (108, 110) positionable in at least one of the wells and a cap member (86) arranged to carry the pipette. The cap member can be releasably fastened to the base member. An extension member (28) defines at least one further well(40, 42, 44) and can be fastened to the base member such that the pipette is then positionable in at least one of the wells of the base and in the further well of the extension member.
Abstract:
Peripherals(18, 20, 22, 24, 26) are connected to a processor (6) and a programmable peripheral interconnect (10) is connected to each peripheral. One of the peripherals (18) is configured to signal an event to the interconnect, and one of the peripherals (20) is configured to respond to a task signal from the interconnect by performing a task. The task-receiving peripheral (20) has a task register (40), addressable by the processor (6), and performs the task in response to a change in the contents of the register (40). The interconnect (10) accesses a memory (14) in which a mapping is stored between an event of a first peripheral (18) and a task of a second peripheral (20), the mapping comprising (i) an identification of the event, and (ii) the address of a task register (40). The mapping causes the interconnect (10) to provide a channel by sending a task signal to the second peripheral (20) in response to a signal of the event from the first peripheral (18).
Abstract:
Static transmitter stations (4,6) are used to determine the position of a mobile receiver unit (10). Each transmitter station transmits an ultrasonic signal comprising a transmitter-specific phase-shifting signature (40). The receiver unit receives a signal and identifies a transmitter station by its signature. It uses the received signal and the identity of the source transmitter station to determine the position of the mobile receiver unit. The signature may comprise two patterns (30,34) phase-shift-key (PSK)-encoded on respective carrier signals of the same frequency but different phase, with the patterns being offset from each other by a transmitter-specific offset. The signal from the transmitter station may also include a PSK-encoded message (44).
Abstract:
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.
Abstract:
An apparatus (7) for down-converting a sampled signal comprises a processing system (206) configured to apply a mixing-and-combining operation repeatedly to successive sub-sequences of N input samples, X, representative of a signal and having an initial sampling rate, M, to generate a sequence of output samples, Y, having an output rate, T, lower than the initial sampling rate M. The sub-sequences of the N input samples, X, are spaced at intervals that correspond to the output rate M. The mixing-and-combining operation generates a respective output sample Y from each sub-sequence, where Y depends on a set of products of the input samples X of the sub-sequence with respective values derived from a periodic mixing signal having a mixing frequency.
Abstract:
A hardware cipher engine (8) encrypts or decrypts a block of input data from a sequence of blocks using a cipher operation where the block of output data depends on the input block's position in the sequence. In a random-access mode of operation, the engine (8) receives a sequence position, receives a block of input data having that position, and outputs a block of output data without outputting data that encrypts, or that decrypts, every block of input data preceding the received position. In some embodiments, the operation is a stream cipher, and the engine (8) generates a sequence of keystream blocks and performs a combining operation between the input block and a keystream block having a corresponding sequence position. In other embodiments, the cipher operation is a block cipher, and the engine (8) generates, but doesn't output, blocks of data that encrypt, or decrypt, one or more blocks preceding the received input block.
Abstract:
A radio communication apparatus (1) receives or generates a base address seed, and generates data-channel access addresses from the seed. Each access address corresponds to a respective data-channel identifier, and is generated by setting a bit at a common first bit position to the value of a bit at a first common predetermined bit position in the base address seed or in the respective data-channel identifier;by setting a bit at a common second bit position to the bitwise complement of this value; and by setting one or more remaining bit positions in dependence on values atone or more bit positions in the base address seed and one or more bit positions in the respective data-channel identifier that are not the first common predetermined bit position. The apparatus (1) can send or receive a radio data packet comprising an access address from the generated set.