What is claimed is:
1. A method for transmitting an adaptive multi-channel packet in power line communication system comprising the steps of:
(a) transmitting a packet from a first node to a second node with a predetermined transmission speed through a power line by using a multi-channel in communication from the first node and the second node;
(b) checking an error of the packet transmitted from the step (a) in the second node, thereafter loading the check result to the packet and transmitting it to the first node through the power line by using a multi-channel;
(c) checking the result of the packet transmitted from the step (b) in the first node, and storing the check result as a database;
(d) transmitting the packet to the second node with any one among the current, downgraded or upgraded transmission speeds through the power line according to the packet transmission successfailure information stored as the database in the step (c); and
(e) transmitting the packet with a stable transmission speed according to the multi-channel by performing repeatedly the steps (b) to (d).
2. The method of claim 1, wherein the packet in the step (a) is a normal packet for transmitting system data and the packet in the step (b) is a control packet for transmitting packet error generationnon-generation information and its own address information.
3. The method of claim 1, wherein in the step (b), the error check of the packet transmitted from the first node through the power line with a predetermined transmission speed is performed by using a CRC(Cyclic Redundancy Check) method.
4. The method of claim 1, wherein the step (b) further comprises the steps of:
(b1) checking the packet error by receiving the packet transmitted from the step (a) through the power line and thereafter when an error is generated in the packet as a result of the check, loading the packet error generation information and its own address information to the packet and transmitting it through the power line; and
(b2) When an error is not generated in the packet as a result of the check in the step (b1), loading the packet error non-generation information and its own address information to the packet and transmitting it through the power line.
5. The method of claim 1, wherein in the step (c), the information is stored as a database in a media access controller (MAC) address.
6. The method of claim 1, wherein the database in the step (c) is periodically upgraded and a period is manually controlled according to a using environment.
7. The method of claim 1, wherein the step (d) further comprises the steps of:
(d1) comparing the number of times of retransmission with a predetermined first reference value when the packet transmission fails according to the packet transmission successfailure information stored as a database in the step (c), retransmitting the packet to the second node through the power line with a predetermined transmission speed when the number of times of retransmission is smaller than the predetermined first reference value as the comparison result, and finishing the packet transmission when the number of times of retransmission is greater than the predetermined first reference value;
(d2) comparing the number of times of transmission with a predetermined second reference value when the packet transmission is successfully performed according to the packet transmission successfailure information stored as a database in the step (c) and transmitting the packet to the second node through the power line in the current transmission speed at the next time when the number of times of transmission is smaller than the predetermined second reference value;
(d3) comparing a transmission failure count value with a predetermined third reference value in the case that the number of times of transmission is greater than the predetermined second reference value as the comparison result of the step (d2) and thereafter transmitting the packet to the second node through the power line in a transmission speed downgraded by one step at the next time when the transmission failure count value is greater than the predetermined third reference value;
(d4) comparing a transmission success count value with a predetermined fourth reference value when the transmission failure count value is smaller than the predetermined third reference value as the comparison result of the step (d3) and thereafter transmitting the packet to the second node through the power line in a transmission speed upgraded by one step at the next time when the transmission success count value is greater than the predetermined fourth reference value; and
(d5) transmitting the packet to the second node through the power line in the current transmission speed at the next time in the case that the transmission success count value is smaller than the predetermined fourth reference value as the comparison result of the step (d4).
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) Apparatus for the fast angular orientation of a surgical instrument with respect to an implantation seat of a prosthesis in a patient’s bone, of the type comprising a moving sensor (16), which can be associated with said surgical instrument, and a fixed sensor (17), which can be integrally fastened to said bone during a surgical operation, said moving sensor (16) and said fixed sensor (17) being provided with position detection means and with signalling means of the detected position to a central memory and processing unit characterised in that said central memory and processing unit comprises calibration means which detect the position of said moving sensor (16) when it is arranged in a fixed position with respect to a line passing through two known points of said bone and, simultaneously, detect the position of said fixed sensor (17) integrally fastened to said bone, and which record such a position as the initial work position.
2) Apparatus as claimed in claim 1, wherein said central memory and processing unit is associated with said moving sensor (16).
3) Apparatus as claimed in claim 2, furthermore comprising a clamp-like device (18) provided with coupling means (33, 34) for steadily and reversibly coupling with said moving sensor (16) and with jaw-like means (35, 36) for locking into position said surgical instrument.
4) Apparatus as claimed in claim 3, wherein said central memory and processing unit comprises indicators of the moving sensor (16) angular positioning and of a target angular positioning, said indicators being provided on a surface of the moving sensor (16) facing the surgeon who grips the surgical instrument, when said moving sensor (16) and said surgical instrument are steadily associated through said clamp (18).
5) Apparatus as claimed in claim 4, wherein said indicators are light type indicators, the indicators of the moving sensor (16) angular positioning consisting of four arrow-shaped LEDs (39) arranged according to the four cardinal directions, the activation of which indicates the direction(s) where the surgeon must incline the instrument to get closer to the target angular positioning, and the indicator of the target angular positioning consisting of a LED (40) which is activated when the surgical instrument is correctly aligned according to the target angular positioning.
6) Apparatus as claimed in claim 2, furthermore comprising a compasses-like device (15) provided with coupling means (30, 31) for steadily and reversibly coupling with said moving sensor (16) and with spreadable arms (32) the free ends of which are rested onto said two known points of said bone for thereby arranging into a fixed position the moving sensor (16) with respect to a line passing through said points.
7) Apparatus as claimed in claim 3, wherein said coupling means (30, 31; 33, 34) consist of tanghole couplings with a univocal coupling position.
8) Apparatus as claimed in claim 1, wherein said central memory and processing unit comprises initial calibration means which detect the position of said mobile sensor (16) and of said fixed sensor (17) when they are arranged, in a pre-set orientation, on a same reference plane outside the patient and such a position is recorded as the initial reference position thereof.
9) Apparatus as claimed in claim 2, wherein said fixed sensor (17) is integrally fastened onto said bone during a surgical operation through a surgical pin.
10) Apparatus as claimed in claim 9, wherein said fixed sensor (17) comprises a box (26) in which independent means for the detection of its own position and means for signalling such detected position to said central memory and processing unit are contained.
11) Apparatus as claimed in claim 9, wherein said fixed sensor (17) comprises a support (26a) provided with multiple reflecting blocks (29a, 29b, 29c, 29d), and said central memory and processing unit furthermore comprises a source of a light radiation (42), a camera (41) apt to capture the images of said reflecting blocks (29a, 29b, 29c, 29d) and a processing programme for analysing said images and providing a remote detection of the exact position of said fixed sensor (17).
12) Apparatus as claimed in claim 1, wherein said bone is the pelvis bone of a human being.
13) Apparatus as claimed in claim 12, wherein said two known points of the pelvis bone are the iliac crests (8, 9).
14) Apparatus as claimed in claim 6, wherein said coupling means (30, 31; 33, 34) consist of tanghole couplings with a univocal coupling position.