1. A sigma-delta analog-to-digital converter for converting band-limited analog signals into corresponding digital signals, said analog-to-digital converter comprising:
a loop sampling and quantization analog-to-digital converter including an input port, and an output port at which output digital signals are generated in response to resonated difference signals applied to said input port;
a loop digital-to-analog converter including an input port coupled to said output port of said loop analog-to-digital converter, for generating an analog reconstruction of said output digital signals;
an input summing arrangement including an input port coupled for receiving said band-limited analog signal and an output port coupled to said input port of said loop sampling and quantization analog-to-digital converter, for summing said band-limited analog signals with said analog reconstruction of said output digital signals and with filtered signals, to form said resonated difference signals, said loop sampling and quantization analog-to-digital converter, said loop digital-to-analog converter, and said input summing arrangement being coupled in a first loop having a first delay; and
an analog filter including a single input port coupled to receive said resonated difference signals, and also including an output port at which said filtered signals are generated, which output port of said analog filter is coupled to said input summing arrangement to form a second loop including said analog filter and said input summing arrangement, which second loop is regenerative and has order greater than one, where order is the number of weighted transversal delays.
2. An analog-to-digital converter according to claim 1, wherein said input summing arrangement comprises:
a first summing circuit including a first input port coupled to receive said band-limited analog signal and a second input port coupled to receive one of said filtered signals and said analog reconstruction of said digital output signals, for summing said one of said filtered signals and said analog reconstruction of said digital output signals with said band-limited analog signals, to thereby generate an intermediate signal; and
a second summing circuit including a first input port coupled to receive said intermediate signal and a second input port coupled to receive the other one of said filtered signals and said analog reconstruction of said digital output signals, for summing said intermediate signals with said other one of said filtered signals and said analog reconstruction of said digital output signals, to thereby generate said resonated difference signals.
3. An analog-to-digital converter according to claim 2, wherein said one of said filtered signals and said analog reconstruction of said digital output signals is said analog reconstruction of said digital output signals, and said other one is said filtered signals.
4. An analog-to-digital converter according to claim 1, wherein said loop sampling and quantization analog-to-digital converter, said loop digital-to-analog converter, and said first summing circuit are located within a first loop, and said first summing circuit and said analog filter are located within a second loop, whereby said first summing circuit is a common element within said first and second loops, said analog-to-digital converter further comprising:
delay means coupled in one of said first and second loops for tending to equalize the delay around said first and second loops for stabilizing said analog-to-digital converter.
5. A sigma-delta analog-to-digital converter for converting band-limited analog signals into corresponding digital signals, said analog-to-digital converter comprising:
a loop sampling and quantization analog-to-digital converter including an input port, and an output port at which output digital signals are generated in response to resonated difference signals applied to said input port;
a loop digital-to-analog converter including an input port coupled to said output port of said loop analog-to-digital converter, for generating an analog reconstruction of said output digital signals;
an input summing arrangement including an input port coupled for receiving said band-limited analog signals and an output port coupled to said input port of said loop sampling and quantization analog-to-digital converter, for summing said band-limited analog signal with said analog reconstruction of said output digital signals and with filtered signals, to form said resonated difference signals, said loop sampling and quantization analog-to-digital converter, said loop digital-to-analog converter, and said input summing arrangement being coupled in a first loop having a first delay; and
an analog filter including an input port coupled to said output port of said input summing arrangement to receive said resonated difference signals, and also including an output port at which said filtered signals are generated, which output port of said analog filter is coupled to said input port of said input summing arrangement to form a second loop including said analog filter and said input summing arrangement, said first and second loops having only linear elements in common.
6. A sigma-delta analog-to-digital converter according to claim 5, wherein said input port of said analog filter is the sole input port of said analog filter.
7. A sigma-delta analog-to-digital converter for converting band-limited analog signals into corresponding digital signals, said analog-to-digital converter comprising:
a loop sampling and quantization analog-to-digital converter including an input port, and an output port at which output digital signals are generated in response to resonated difference signals applied to said input port;
a loop digital-to-analog converter including an input port coupled to said output port of said loop analog-to-digital converter, for generating an analog reconstruction of said output digital signals;
an input summing arrangement including an input port coupled for receiving said band-limited analog signals and an output port coupled to said input port of said loop sampling and quantization analog-to-digital converter, for summing said band-limited analog signal with said analog reconstruction of said output digital signals and with filtered signals, to form said resonated difference signals, said loop sampling and quantization analog-to-digital converter, said loop digital-to-analog converter, and said input summing arrangement being coupled in a first loop having a first delay; and
an analog filter including an input port coupled to said output port of said input summing arrangement to receive said resonated difference signals, and also including an output port at which said filtered signals are generated, which output port of said analog filter is coupled to said input port of said input summing arrangement to form a second loop including said analog filter and said input summing arrangement, said first and second loops having only said input summing arrangement in common.
8. A sigma-delta analog-to-digital converter according to claim 7, wherein said input port of said analog filter is the sole input port of said analog protoresonator filter.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A connecting device for interconnecting sections of a connecting element in a vertebral column implant, said connecting element comprising
a rigid connecting element section, said rigid connecting element section having two ends,
a sleeve integral with each of the two ends of the rigid connecting element section,
each of the sleeves opening in a direction extending away from a central portion of the rigid connecting element section,
each of the sleeves cooperating with an elastic connecting element section for securing the elastic connecting element section in the sleeve.
2. The connecting device according to claim 1, wherein the elastic connecting element section has two ends, each of the two ends is connected to a respective said rigid connecting element section.
3. The connecting device according to claim 1, wherein the rigid connecting element section is made of a metal alloy.
4. The connecting device according to claim 1, wherein the elastic connecting element is made of a biocompatible synthetic material based on polyurethane.
5. The connecting device according to claim 4, wherein a surface of the elastic connecting element is provided with encircling ribs and grooves.
6. The connecting device according to claim 1, wherein an inner walling of the sleeve is provided with at least one projection.
7. The connecting device according to claim 6, wherein the at least one projection is ribs, aligned transversely to the sleeve, running along the inner walling.
8. The connecting device according to claim 6, wherein the at least one projection is at least one rib running along the inner walling, transversely to the sleeve, over at least one portion of the circumference of the inner walling.
9. The connecting device according to claim 6, wherein the at least one projection is at least one bolt with a mushroom-shaped swelling which projects into the sleeve.
10. The connecting device according to claim 6, wherein the at least one projection of the inner walling including a tooth.
11. The connecting device according to claim 6, wherein the at least one projection of the inner walling is located at a free end of the sleeve.
12. The connecting device according to claim 11, wherein the at least one projection is a collar.