1. A method for driving a motor-driven mechanical system using a calculated mechanical system specific resonant frequency, comprising:
applying a test drive signal to a motor of a mechanical system to cause oscillatory behavior in the mechanical system;
capturing a back channel electrical signal induced by the motor from the oscillatory behavior;
calculating a resonant frequency of the mechanical system from the captured electrical signal; and
storing the calculated resonant frequency in a register, the resonant frequency to be used in a run time mode.
2. The method of claim 1, further comprising:
applying a drive signal to the motor of the mechanical system in the run time mode, the drive signal having substantially zero energy at the calculated resonant frequency.
3. The method of claim 1, wherein the motor is a lens driver motor.
4. A drive signal generator, comprising:
a test signal generator having an output for connection to a motor of a mechanical system;
a back channel sensor to capture an electrical signal induced by the motor from oscillatory behavior in the mechanical system;
a processor to calculate a resonant frequency of the mechanical system from the captured electrical signal; and
a register to store the calculated resonant frequency.
5. The drive signal generator of claim 4, wherein the accumulator generates a drive signal in a run time operation mode, the drive signal having substantially zero energy at the stored resonant frequency.
6. The drive signal generator of claim 4, further comprising a digital to analog converter to generate an analog representation of the test drive signal.
7. A system comprising;
a mechanical structure having a drive motor;
a drive signal generator coupled to the drive motor, comprising:
an initialization circuit, operable in an initialization mode to generate a test drive signal to cause oscillatory behavior in the mechanical structure;
a back channel sensor to capture an electrical signal induced by the motor from the oscillatory behavior;
a processing unit to calculate a resonant frequency of the mechanical structure from the captured electrical signal; and
a drive circuit, operable in a run time mode, including a register to store the calculated resonant frequency.
8. The system of claim 7, wherein the drive circuit is further operable to generate a drive signal in the run time mode, the drive signal having substantially zero energy at the stored resonant frequency.
9. The system of claim 7, wherein the drive signal generator further comprising a digital to analog converter to generate an analog representation of the test drive signal.
10. A system comprising:
a mechanical structure having a drive motor; and
a back channel detection system, comprising:
an initialization circuit, operable in an initialization mode to applying a test drive signal to the drive motor;
a back channel sensor to monitor a signal line from the drive motor for an electrical signal induced by the drive motor due to movement of the mechanical structure;
a processing unit to calculate a characteristic value of the mechanical structure from the monitored back channel electrical signal; and
a drive circuit, operable in a run time mode, including a register to store the calculated characteristic value.
11. A method for driving a motor-driven mechanical system, comprising:
applying a drive signal to a motor of a mechanical system to cause oscillatory behavior in the mechanical system;
capturing a magnitude estimate of the oscillatory behavior;
adjusting a resonant frequency of the mechanical system based on the magnitude estimate; and
storing the adjusted resonant frequency in a register.
12. The method of claim 11 wherein the drive signal is a test drive signal.
13. The method of claim 11 wherein the drive signal is a normal operation drive signal.
14. A drive signal generator, comprising:
a driver circuit to generate a drive signal to be applied to a motor;
a feedback circuit to capture oscillations caused by the motor due to movement of a mechanical system;
a processor to adjust a resonant frequency according to the captured oscillations; and
a register to store the resonant frequency.
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 compound of the formula I:
37
wherein:
A and A are independently the same or different group of the formula II:
38
wherein:
Ris H, CH3, C(CH3)2, ORa, N(Ra)2, N(Ra)ORa or -DP
R is H or CH3; Ra is H, C1-C3 alkyl;
D is a bond, C1-3 alkylene, C(O), S(O) or S(O)2;
P is an optionally substituted, mono or bicyclic carbo- or heterocycle;
R is H, any of the sidechains found in the natural amino acids, carboxacetamide, or a group (CH2)nDP;
M is a bond or C(O)N(R)-;
Q is absent, a bond, CH(OH) or CH2;
or R together with Q, M and R define an optionally substituted 5 or 6 membered carbo- or heterocyclic ring which is optionally fused with a further 5 or 6 membered carbo- or heterocyclic ring;
with the proviso that R is ORa, N(Ra)2, N(Ra)ORa or -DP, if M is a bond and Q is absent;
X is H, OH, OCH3;
Y is H, OH, OCH3, but X and Y are not both H;
Z and Z are independently (CH2)mP where P is as defined above;
n and m are independently 0, 1 or 2;
and pharmaceutically acceptable salts and prodrugs thereof.
2. A compound according to claim 1, wherein A andor A are a group of the formula IIa:
39
wherein
n is 0, 1 or 2;
R is methyl or methyloxy; and
R is hydrogen, methyl, ethyl, isopropyl, cycloalkyl such as cyclopropyl, cyclobutyl or cyclohexyl, cycloalkenyl, benzyl, carboxacetamide or 4-imidazolylmethy or a side chain found in the natural amino acids.
3. A compound according to claim 2 wherein n is 0 and R is methyl.
4. A compound according to claim 1, wherein A andor A are a group of the formula IIb:
40
wherein
R is as defined in claim 2 and
R is hydrogen or methyl.
5. A compound according to claim 1, wherein A andor A are a group of the formula IIc:
41
wherein
Q is a bond, methylene or C(OH),
R is an optionally substituted carbo- or heterocyclic group; and
R and R are as defined in claim 2.
6. A compound according to claim 3, 4 or 5 wherein R is the side chain of leucine, isoleucine, asparagine, histidine or proline and most preferably valine.
7. A compound according to claim 1, wherein A andor A are a group of the formula III:
42
where
R is H or CH3,
R1 is H, NR4R4, C(O)R3, CR3R4 or a monocyclic, optionally substituted, carbo- or heterocycle;
R2 is OH, or together with R1 is O, or if R1 is NR4R4, then R2 may be H;
R3 is H, halo, C1-C3 alkyl, OR5, NR4R4;
R4 is H, C1-C3 alkyl;
R5 is H or a pharmaceutically acceptable ester;
R6 is OH, NH2, carbamoyl or carboxy;
R7 is hydrogen, C1-C4 straight or branched alkyl or together with the adjacent carbon atoms forms a fused phenyl or pyrimidine.
8. A compound according to claim 7, wherein the moiety of formula III has the structure:
43
9. A compound according to claim 1, wherein both A and A are identical.
10. A compound according to claim 1, wherein Z andor Z is benzyl unsubstituted or substituted with one to three substituents selected from halo, methoxy, hydroxy, amino, cyano, hydroxymethyl, aminomethyl, morpholinethoxy, alkylsulfonyl, carbamoyl, benzyloxy phenyl (itself substituted as defined herein) or a 5 or 6 membered heterocycle containing one or two hetero atoms such as thiophene, pyrimidine, N-morpholine, N-piperidine, N-piperazine, N-methyl-N-piperazine, N-pyrrolidone, N-pyrrolidine and the like, optionally substituted as defined herein.
11. A compound according to claim 10 wherein Z andor Z is benzyl, 2-fluorobenzyl, 2-methylbenzyl, 2,4-difluorobenzyl, 4-fluorobenzyl, 4-bromobenzyl, 4-phenylbenzyl, 4-thiophenylbenzyl, 4-(4-nitrophenyl)benzyl, 4-thienylbenzyl, 4-thiazolylbenzyl or 4-(pyridyl)benzyl.
12. A compound according to claim 1, wherein Y is H andor X is OH.
13. A compound accoridng to claim 1, having the 2R, 3R, 4R, 5R configuration.
14. A pharmaceutical composition comprising a compound according to any one of claims 1-5 and 7-13 and a pharmaceutically acceptable carrier or diluent therefor.
15. A method for inhibiting the replication of HIV comprising administering an effective amount of a compound as defined in any one of claims 1-5 and 7-13 to a subject afflicted with said condition.
16. A method for the preparation of a compound of the formula I where X, Y, Z and Z are as defined in claim 1 and each of A and A are independently:
a group of the formula II or a conventional protease P-2P-2 filling group, the method comprising:
i) O-alkylation of an L-mannaric-1,4:6,3-di-lactone to form the Z and Z groups,
ii) opening of the lactone with similar or different primary or secondary amines to form the respective A and A groups; and
iii) optional conversion of the C-3 and C-4 to the appropriate X and Y groups.