Patent US4035957A successfully refreshed from Google Patents.
Patent EP0195670A2 successfully refreshed from Google Patents.
EP0195670A2
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EP
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Function generator for a nuclear magnetic resonance system
Assignee: Advanced NMR Systems Inc
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Filing: 1986-03-19
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Granted: —
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Expires: 2006-03-19
Abstract
Abstract A modular function generator for generating a plurality of analog waveforms for use in an NMR imaging system includes a plurality of waveform synthesizer modules (50) which are interconnected by a main bus (52) to a central controller (56). Each synthesizer is adapted to produce one analog waveform for the NMR imaging system. Each synthesizer module includes a memory (70) and an address sequencer (72) which produces a sequence of addresses which control the retrieval of data from the memory. Each data word of the memory contains several fields. An instruction field and a general data field control the address sequencer so that the sequence of addresses is, in turn, controlled by the memory data. Other fields from the memory define analog and digital outputs produced by the synthesizer module. The fields are generated by program control means which are organised to have data files which define a set of elementary analog waveform segments and subroutines which are controlled by a main program. The execution of each subroutine produces a segment of an analog waveform. The subroutines generate a segment by accessing given data files and concatenating a plurality of elementary segments into a single analog output Each synthesizer also includes a system clock (180) which has a clock speed-up mode for I executing background program steps between adjacent clock pulses of its primary clock signal. The synthesizer modules are interconnected by an interchannel communications bus - ,(66) which allows each synthesizer to signal every other synthesizer whereby the operations of the synthesizers can be synchronized. The contents of the memory of each synthesizer can be modified by the central controller so that the function performed by each synthesizer and the shape of each analog waveform is completely definable. I
Inventors
- 👤 Randal L. Briggs
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 19:57
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/28; G01R33/32; G01R33/36; G01R33/3607
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
133 words
A waveform synthesizer for an NMR imaging system, characterised by a memory (70); an address sequencer - (72) for producing a sequence of addresses (76) for the memory; means (242) for entering data into the memory from a source (26) external to the synthesizer; means (74) for sequentially retrieving portions of the data from the memory in accordance with the sequence of addresses, the data retrieved from the memory including an instruction field for controlling the operation of the address sequencer, an analog waveform field for defining at least one analog waveform output and a digital output field for producing a plurality of digital outputs; analog waveform synthesizing means (168,170) responsive to the analog waveform field for producing the or each analog waveform output; and program means for generating the analog waveform field.
Claim 2
Dependent Claim
133 words
A waveform synthesizer for an NMR imaging system, characterised by a memory (70); an address sequencer - (72) for producing a sequence of addresses (76) for the memory; means (242) for entering data into the memory from a source (26) external to the synthesizer; means (74) for sequentially retrieving portions of the data from the memory in accordance with the sequence of addresses, the data retrieved from the memory including an instruction field for controlling the operation of the address sequencer, an analog waveform field for defining at least one analog waveform output and a digital output field for producing a plurality of digital outputs; analog waveform synthesizing means (168,170) responsive to the analog waveform field for producing the or each analog waveform output; and program means for generating the analog waveform field.
Claim 3
Dependent Claim
65 words
A synthesizer according to claim 1, characterised in that the program means includes data field means (200) for defining a set of elementary waveform segments, subroutine means (194) for generating the analog waveform field as a concatenation of at least one of the elementary waveform segments and program control means for controlling the sequence of access to the data file means and the subroutine means.
Claim 4
Dependent Claim
85 words
A synthesizer according to claim 1 or claim 2, characterised by system clock means (180) for producing a clock signal which determines the frequency at which the addresses are produced, the system clock means including means (118) for producing a first clock signal (120) having clock pulses of a predetermined frequency, and for producing intermediate clock pulses (124) which can be interposed between adjacent pulses of the clock pulses of the predetermined frequency to increase the rate at which the sequence of addresses is generated.
Claim 5
Dependent Claim
202 words
A waveform synthesizer for generating at least one analog waveform and a plurality of digital outputs for an NMR imaging system, characterised by address sequencer means (72) for producing a sequence of addresses; a programmable memory (70) for storing therein digital and control information in the form of data words, each of the data words including a plurality of data fields, the programmable memory being responsive to the addresses to output the data words; a pipeline register (74) coupled to the memory and having a capacity to hold at least one of the data words, the address sequencer means being coupled to the pipeline register to receive therefrom an instruction field which defines an operation to be performed by the address sequencer means and digital output fields which define the state of the digital outputs; means (168,170) for producing the analog waveform, the means being coupled to the pipeline register and being responsive to an analog data field of the pipeline register to produce the analog waveform; and means (242) for receiving data from a source external to the synthesizer and entering the data into the programmable memory, whereby the waveshape of the analog waveform and the digital output may be altered.
Claim 6
Dependent Claim
202 words
A waveform synthesizer for generating at least one analog waveform and a plurality of digital outputs for an NMR imaging system, characterised by address sequencer means (72) for producing a sequence of addresses; a programmable memory (70) for storing therein digital and control information in the form of data words, each of the data words including a plurality of data fields, the programmable memory being responsive to the addresses to output the data words; a pipeline register (74) coupled to the memory and having a capacity to hold at least one of the data words, the address sequencer means being coupled to the pipeline register to receive therefrom an instruction field which defines an operation to be performed by the address sequencer means and digital output fields which define the state of the digital outputs; means (168,170) for producing the analog waveform, the means being coupled to the pipeline register and being responsive to an analog data field of the pipeline register to produce the analog waveform; and means (242) for receiving data from a source external to the synthesizer and entering the data into the programmable memory, whereby the waveshape of the analog waveform and the digital output may be altered.
Claim 7
Dependent Claim
74 words
A synthesizer according to claim 4, characterised by system clock generating means (180) for- producing a clock signal which determines the frequency at which the addresses are generated, the system clock means including means (118) for producing a first clock output (120) having clock pulses of a predetermined frequency, the address sequencer means (72) and the pipeline register (74) being coupled to the clock generating means and being synth- ronized to the clock signal.
Claim 8
Dependent Claim
49 words
A synthesizer according to claim 5, characterised in that the system clock generating means (180) further includes means for producing intermediate clock pulses (124) which can be interposed between adjacent clock pulses of the first clock output (120) to increase the total number of pulses of the clock signal.
Claim 9
Dependent Claim
25 words
A synthesizer according to claim 6, characterised in that the intermediate clock pulses (124) are enabled for carrying out background program steps within the synthesizer.
Claim 10
Dependent Claim
46 words
A synthesizer according to any one of claims 4 to 7, characterised in that the address sequencer means (72) includes means for producing a sequence of increasing addresses or branch addresses, the addresses being developed in accordance with the instruction field from the pipeline register (74).
Claim 11
Dependent Claim
30 words
A synthesizer according to any one of claims 4 to 8, characterised by at least one interval timer counter (156) for timing events of the synthesizer for producing time delays.
Claim 12
Dependent Claim
41 words
A synthesizer according to any one of claims 4 to 9, characterised by input means for sensing the activation of at least one input signal, and means for synchronizing predefined operations of the synthesizer to the activation of the input signal.
Claim 13
Dependent Claim
26 words
11 . A synthesizer according to claim 10, characterised in that the input signal (34) is a signal indicative of a physiological state of a patient.
Claim 14
Dependent Claim
23 words
A synthesizer according to any one of claims 4 to 11, characterised in that the programmable memory (70) is a random access memory.
Claim 15
Dependent Claim
16 words
A synthesizer according to claim 12, characterised in that each data word is a 64-bit word.
Claim 16
Dependent Claim
37 words
A synthesizer according to claim 11 or claim 12, characterised in that the random access memory (70) is responsive to the addresses to produce a respective data word after a delay of between 50 to 100 nanoseconds.
Claim 17
Dependent Claim
60 words
A synthesizer according to any one of claims 12 to 14, characterised in that the random access memory includes a data output port (78), the pipeline register (74) having inputs connected to the data output port and a clock input (134) for clocking data present at the data output port into the pipeline register in response to the clock signal.
Claim 18
Dependent Claim
35 words
A synthesizer according to claim 13, characterised in that a plurality of the data words include the instruction field, a general data field, a DAC field, a digital outputs field, and a control outputs field.
Claim 19
Dependent Claim
27 words
1 7. A synthesizer according to 'claim 16, characterised in that the general data field and the instruction field are coupled to the address sequencer means (72).
Claim 20
Dependent Claim
29 words
A synthesizer according to claim 16 or claim 17, characterised in that the control outputs field includes a fast clock enable output (90) for enabling the intermediate clock pulses.
Claim 21
Dependent Claim
28 words
1 9. A synthesizer according to claim 18, characterised in that the clock generating means produces the intermediate clock pulses having a frequency of at least 5.3 MHZ.
Claim 22
Dependent Claim
68 words
A synthesizer according to any one of claims 4 to 19, characterised in that the analog waveform producing means (168,170) includes a digital to analog converter (168) coupled to the pipeline register (74) for producing an intermediate analog output in. response to a DAC field from the pipeline register, and a multiplying digital to analog converter (170) for scaling the intermediate analog output and producing the analog waveform.
Claim 23
Dependent Claim
41 words
A synthesizer according to claim 20, characterised in that the multiplying digital to analog converter (170) includes means responsive to a data field from the pipeline register - (74) for adjusting the scaling level of the multiplying digital to analog converter.
Claim 24
Dependent Claim
48 words
A synthesizer according to claim 21, characterised by means for synchronously storing the digital to analog converter field and the data field for the multiplying digital to analog converter (170) in the digital to analog converter - ( 1 68) and the multiplying digital to analog converter, respectively.
Claim 25
Dependent Claim
76 words
A synthesizer according to any one of claims 4 to 22, characterised by program means for synthesizing the analog waveform, the program means including data field means - (200) for defining a set of elementary waveform segments, subroutine means (19 4 ) for generating the analog waveform by concatenating at least some of the elementary waveform segments, and program control means for controlling the sequence of access to the data field means and the subroutine means.
Claim 26
Dependent Claim
20 words
A synthesizer according to claim 23, characterised in that the set of elementary waveform segments includes sinusoidal and ramp segments.
Claim 27
Dependent Claim
86 words
A synthesizer ording to any one of claims 4 to 24, characterised in that the means (242) for entering data into the memory (70) includes means (244) for interfacing the synthesizer to a address/datalcontrol bus (52); address and data buffers (2 4 8 , 246) selectively coupleable to the memory; and control logic means (250) for producing control outputs for the address sequencer means (72) and for the data entry means to arbitrate access to the programmable memory and to control data entry into the memory.
Claim 28
Dependent Claim
29 words
A synthesizer according to claim 25, characterised in that the memory (70) is organised in data words which are . larger than the data width of the data buffer-(246).
Claim 29
Dependent Claim
57 words
A synthesizer according to claim 26, characterised in that the data words of the memory (70) are 64 bits wide and the data buffer (2 4 6) is 16 bits wide; and the control logic means (250) for entering data into the memory includes means for selectively enabling a portion of the memory for entering data thereinto.
Claim 30
Dependent Claim
48 words
A synthesizer according to any one of claims 25 to 27, characterised in that the control logic means (250) includes programable array logic (PAL) integrated circuits programmable to generate the control outputs whereby modification of the control outputs is effected by PAL substitution instead of circuit interconnection modifications.
Claim 31
Dependent Claim
47 words
A synthesizer according to claim 5, characterised in that the digital outputs are synchronized to the clock pulses of the first clock output (120); and in that means (156) is provided for selectively defying at least one of the digital outputs with respect to the clock output
Claim 32
Dependent Claim
51 words
A synthesizer according to claim 29, characterised in that the predetermined frequency of the first clock output - (120) is about 1 MHZ; and the selective delaying means - (156) is adapted to delay said at least one digital output by up to 1 usec in increments of about 62.5 nanoseconds.
Claim 33
Dependent Claim
25 words
A synthesizer according to claim 29 or claim 30, characterised in that the delayed digital output is usable for triggering an analog to digital converter.
Claim 34
Dependent Claim
10 words
A function generator for an NMR imaging system, characterised by
Claim 35
Dependent Claim
10 words
A function generator for an NMR imaging system, characterised by
Claim 36
Dependent Claim
165 words
(a) a plurality of independently operable waveform synthesizers (50), each including a memory (70); address sequencer means (72) for producing a sequence of addresses for the memory; program data stored in the memory; means (74) for sequentially retrieving portions of the data from the memory in accordance with the sequence of addresses, the data retrieved from the memory including an instruction field for controlling the operation of the address sequencer means, an analog waveform field for defining at least one analog waveform output, and a digital output field for producing a plurality of digital outputs; analog waveform synthesizing means for producing an analog waveform from the analog waveform field; and program means for generating said analog waveform fields; (b) a central controller (56) connected to the plurality of waveform synthesizers and including means for loading the memory of each of the plurality of synthesizer with the program data; and (c) a datafaddress/control bus (52) for interconnecting the central controller and the plurality of waveform synthesizers.
Claim 37
Dependent Claim
165 words
(a) a plurality of independently operable waveform synthesizers (50), each including a memory (70); address sequencer means (72) for producing a sequence of addresses for the memory; program data stored in the memory; means (74) for sequentially retrieving portions of the data from the memory in accordance with the sequence of addresses, the data retrieved from the memory including an instruction field for controlling the operation of the address sequencer means, an analog waveform field for defining at least one analog waveform output, and a digital output field for producing a plurality of digital outputs; analog waveform synthesizing means for producing an analog waveform from the analog waveform field; and program means for generating said analog waveform fields; (b) a central controller (56) connected to the plurality of waveform synthesizers and including means for loading the memory of each of the plurality of synthesizer with the program data; and (c) a datafaddress/control bus (52) for interconnecting the central controller and the plurality of waveform synthesizers.
Claim 38
Dependent Claim
58 words
A function generator according to claim 32, characterised by interchannel communications bus means (66), for interconnecting the plurality of waveform synthesizers (50) in a manner which allows each of the plurality of waveform synthesizers to signal every other one of the plurality of waveform synthesizers whereby the operation of the plurality of waveform synthesizers can be synchronized. __
Claim 39
Dependent Claim
86 words
3 4 . A function generator according to claim 32, characterised in that the interchannel communication bus means is in the form of a plurality of lines, each one of the synthesizers (50) being responsive to sense the activation of a given respective one of the lines and each one of the plurality of waveform synthesizers being adapted to activate others than the line it is responsive to, whereby each of the waveform synthesizers can signal any or all of the others of the waveform synthesizers.
Claim 40
Dependent Claim
62 words
A function generator according to claim 33 or claim 34, characterised in that each one of the plurality of waveform synthesizers (50) is carried on a respective printed circuit board; and the bus (66) includes a back plane which is adapted to receive the printed circuit boards whereby a modular, configurable and expandable function generator for an NMR imaging system is provided.
Claim 41
Dependent Claim
78 words
A function generator according to any one of claims 32 to 35, characterised in that each one of the plurality of waveform synthesizers (50) comprises system clock generating means (180) for producing a clock signal having first clock pulses (120) of a predetermined frequency, and intermediate clock pulses (124) which can be interposed between the first clock pulses of the predetermined frequency to increase the total number of pulses of the clock signal within a given time period.
Claim 42
Dependent Claim
27 words
A function generator according to claim 36, characterised in that the intermediate clock pulses (124) are produced for carrying out background program steps within the synthesizer (50).
Claim 43
Dependent Claim
53 words
A function generator according to any one of claims 32 to 37, characterised in that each one of the waveform synthesizers (50) further comprises input means for sensing the activation of at least one input signal and means for synchronizing predefined operations of the waveform synthesizer to the activation of the input signal.
Claim 44
Dependent Claim
85 words
A function generator according to any one of claims 32 to 38, characterised in that each one of the waveform synthesizers (50) further comprises a pipeline register (74); and the analog waveform synthesizing means include a digital to analog converter (168) coupled to the pipeline register for producing an intermediate analog output in response to a changing digital to analog converter field from the pipeline register, and a multiplying digital to analog converter (170) for scaling the intermediate analog output and producing the analog waveform.
Claim 45
Dependent Claim
82 words
A function generator according to any one of claims 32 to 39, characterised in that the program means of each one of the plurality of waveform synthesizers (50) includes data file means (200) for defining a set of elementary waveform segments, subroutine means (19 4 ) for generating at least a DAC field by concatenating at least some of the elementary waveform segments, and program control means for controlling the sequence of access to the data file means and the subroutine means.
Claim 46
Dependent Claim
32 words
A function generator according to any one of claims 32 to 40; characterised by a host computer interface unit (58) for allowing the function generator to interface to a data processing computer.
Claim 47
Dependent Claim
49 words
A function generator according to any one of claims 32 to 41, characterised by a global memory (54) in the form of a printed circuit board connected to the data/address/control bus (52) to provide a central memory for the central controller (56) and said plurality of waveform synthesizers (50).
Claim 48
Dependent Claim
177 words
An NMR imaging system, characterised by magnet means (14) for producing at least one magnetic field adapted to surround at least a portion of a patient (16); a transmitter (20) and a gradient power supply (18) for powering and controlling the magnet means; a receiver - (22) for sensing electromagnetic radiation emitted from the patient in response to the magnetic field or fields; a function generator (12) connected to the transmitter and the receiver for producing a plurality of analog waveforms for operating the transmitter and the gradient power supply, the function generator being in accordance with any one of claims 32 to 42; an analog to digital converter (24) for receiving the electromagnetic radiation from the patient and converting the radiation into a digital signal, the converter being controlled to produce the digital output by at least one of the waveform synthesizers; and computer and display means - (26,46) for receiving the digital data from the analog to digital converter, analysing the data, composing an image of internal structures of the patient, and displaying the image.
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