1. An apparatus for measuring a blood pressure of a subject, comprising:
a cuff placed around the subject’s arm containing an artery;
an inflating unit, coupled to the cuff, for inflating the cuff;
a pressure transducer coupled to the cuff; and
a controllingprocessing unit, coupled to the cuff, the inflating unit and the pressure transducer, respectively, for controlling the inflating unit to inflate the cuff to an initial inflation pressure, controlling the cuff to be deflated from the initial inflation pressure, obtaining a cuff pressure signal and a sequence of raw oscillometric pulse amplitudes relating to counter-pressure of the artery from the pressure transducer as the cuff is deflated from the initial inflation pressure, calculating a respective weight for each of the raw oscillometric pulse amplitudes, correcting each of the raw oscillometric pulse amplitudes based on the weights to obtain a sequence of current oscillometric pulse amplitudes replacing the raw oscillometric pulse amplitudes, defining a maximum oscillometric pulse amplitude among the current oscillometric pulse amplitudes, determining a systolic pressure relating to the blood pressure of the subject based on the maximum oscillometric pulse amplitude, the cuff pressure signal and a first ratio, and determining a diastolic pressure relating to the blood pressure of the subject based on the maximum oscillometric pulse amplitude, the cuff pressure signal and second ratio.
2. The apparatus of claim 1, further comprising a measuring device, coupled to the controllingprocessing unit and disposed in the cuff, for measuring a circumference value relating to the subject’s arm wherein the controllingprocessing unit comprises a lookup table, obtains the circumference value from the measuring device, and determines the first ratio and the second ratio in accordance with the circumference value and the lookup table.
3. The apparatus of claim 1, wherein the controllingprocessing unit applies a set of fuzzy logic rules to the raw oscillometric pulse amplitudes to calculate the respective weight for each of the raw oscillometric pulse amplitudes.
4. The apparatus of claim 1, wherein the controllingprocessing unit corrects each of the raw oscillometric pulse amplitudes (OA) by the steps of:
by use of the raw oscillometric pulse amplitudes neighboring said one raw oscillometric pulse amplitude (OA) and having weights higher than a threshold, calculating a respective target oscillometric pulse amplitude (OA) in a curve-fitting way; and
calculating the current oscillometric pulse amplitude (OA) replacing said one raw oscillometric pulse amplitude (OA) by the following formula:
current OA=\u03c9\xd7raw OA+(1\u2212\u03c9)\xd7target OA, where \u03c9 represents the weight of the said one oscillometric pulse amplitude.
5. A method for measuring a blood pressure of a subject by use of a cuff placed around the subject’s arm containing an artery, said method comprising the steps of:
inflating the cuff to an initial inflation pressure;
obtaining a cuff pressure signal and a sequence of raw oscillometric pulse amplitudes relating to counter-pressure of the artery from a pressure transducer coupled to the cuff as the cuff is deflated from the initial inflation pressure;
calculating a respective weight for each of the raw oscillometric pulse amplitudes;
based on the weights, correcting each of the raw oscillometric pulse amplitudes to obtain a sequence of current oscillometric pulse amplitudes replacing the raw oscillometric pulse amplitudes;
defining a maximum oscillometric pulse amplitude among the current oscillometric pulse amplitudes; and
based on the maximum oscillometric pulse amplitude, the cuff pressure signal, a first ratio and a second ratio, determining a systolic pressure and a diastolic pressure relating to the blood pressure of the subject.
6. The method of claim 5, further comprising the steps of:
obtaining a circumference value relating to the subject’s arm the cuff pressure signal from a measuring device in the cuff; and
determining the first ratio and the second ratio in accordance with the circumference value and a lookup table.
7. The method of claim 5, wherein the step of calculating the respective weight for each of the raw oscillometric pulse amplitudes is performed by applying a set of fuzzy logic rules to the raw oscillometric pulse amplitudes.
8. The method of claim 7, wherein the step of correcting each of the raw oscillometric pulse amplitudes (OA) is performed by the steps of:
by use of the raw oscillometric pulse amplitudes neighboring said one raw oscillometric pulse amplitude (OA) and having weights higher than the threshold, calculating a respective target oscillometric pulse amplitude (OA) in a curve-fitting way; and
calculating the current oscillometric pulse amplitude (OA) replacing said one raw oscillometric pulse amplitude (OA) by the following formula:
current OA=\u03c9\xd7raw OA+(1\u2212\u03c9)\xd7target OA, where \u03c9 represents the weight of the said one oscillometric pulse amplitude.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-10. (canceled)
11. A varistor fuse element, comprising:
a cylindrical fuse including an electrically insulating fuse body that defines a longitudinal passage, wherein first and second electrically conductive fuse contacts are located on opposite ends of the fuse body, and wherein the longitudinal passage includes an arc extinguishing material;
a cylindrical varistor that is located in the longitudinal passage, that includes a varistor body having a resistance that is dependent on voltage, and that is serially electrically connected to the fuse with an electrically conductive first varistor electrode located on an external surface of the varistor body and electrically connected to the first fuse contact, and an electrically conducive second varistor electrode located on an internal surface of the varistor body such that the first and second varistor electrodes are separated by the varistor body; and
an electrically conductive melting member connecting the second fuse contact and the second varistor electrode in order to connect the first and second fuse contacts, wherein the melting member includes a weak portion having a pre-determined cross-section that is operable to melt and interrupt the connection between the first and second fuse contacts when the fuse is electrically overloaded.
12. The varistor fuse element of claim 11, wherein the weak portion of the melting member comprises a pre-determined transversal cross-section.
13. The varistor fuse element of claim 12, wherein a solder electrically connects the melting member to second varistor electrode.
14. The varistor fuse element of claim 13, wherein the weak portion of the melting member is located adjacent to the solder.
15. The varistor fuse element of 14, wherein the second varistor electrode is connected to the melting member by the solder until the solder melts.
16. The varistor fuse element of claim 15, wherein the melting member is pre-tensioned prior to connection to second varistor electrode by the solder such that the melting member is operable to deflect away from the second varistor electrode when the solder melts.
17. The varistor fuse element of claim 13, wherein the melting temperature of the solder is lower than a melting temperature of the melting member and a melting temperature of the second varistor electrode.
18. The varistor fuse element of claim 13, wherein the solder includes a resistance that increases in response to increasing temperature.
19. The varistor fuse element of claim 11, wherein the arc extinguishing material includes silica.
20. A varistor fuse element, comprising:
an electrically insulting cylindrical fuse body having a first end and a second end opposite the first end, wherein the fuse body defines a longitudinal passage extending from the first end to the second end;
a electrically conductive first fuse contact located on the first end of the fuse body;
a electrically conductive second fuse contact located on the second end of the fuse body;
a cylindrical voltage-dependent-resistance varistor body located in the longitudinal passage and including an external surface and an internal surface;
an electrically conductive first varistor electrode located on the external surface of the varistor body and electrically connected to the first fuse contact;
an electrically conducive second varistor electrode located on the internal surface of the varistor body;
an electrically conductive melting member connecting the second fuse contact and the second varistor electrode in order to connect the first fuse contact and the second fuse contact, wherein the melting member includes a portion that is operable to melt and interrupt the connection between the first contact and the second fuse contact when the fuse is electrically overloaded; and
an arc extinguishing material located in the longitudinal passage adjacent the melting member.
21. The varistor fuse element of claim 20, wherein the weak portion of the melting member comprises a pre-determined transversal cross-section.
22. The varistor fuse element of claim 21, wherein a solder electrically connects the melting member to second varistor electrode.
23. The varistor fuse element of claim 22, wherein the weak portion of the melting member is located adjacent to the solder.
24. The varistor fuse element of 23, wherein the second varistor electrode is connected to the melting member by the solder until the solder melts.
25. The varistor fuse element of claim 24, wherein the melting member is pre-tensioned prior to connection to second varistor electrode by the solder such that the melting member is operable to deflect away from the second varistor electrode when the solder melts.
26. The varistor fuse element of claim 22, wherein the melting temperature of the solder is lower than a melting temperature of the melting member and a melting temperature of the second varistor electrode.
27. The varistor fuse element of claim 22, wherein the solder includes a resistance that increases in response to increasing temperature.
28. The varistor fuse element of claim 21, wherein the arc extinguishing material includes silica.