WO 01/26544 PCT/AU00/01234 1 TRANSTELEPHONIC BLOOD PRESSURE MONITOR The present invention relates to physiological monitoring of patients and, in particular, to physiological signal acquisition apparatus which provides real time and/or recorded data transmission over a telephone network to a remote location 5 where it is decoded and analysed. BACKGROUND TO THE INVENTION The management of hypertension , ie high blood pressure, continues to be one of the most important issues facing physicians. This is due to the widespread prevalence of the disorder, as there are an estimated sixty million persons in the 10 United States alone, and partly because of the consequences of uncontrolled, poorly treated hypertension which can lead to the occurrences of strokes, heart attacks and heart failures. Self monitoring of blood pressure by patients at their own homes, offices and the like offers the potential for improved and cost effective management of 15 hypertension . Home monitoring of blood pressure offers the availability of more frequent measurement readings that can give a precise estimate of blood pressure trends over long periods of time. One aspect of blood pressure self monitoring and management that causes concerns is a so called "reporting bias". It is believed that a means of reducing 20 reporting bias error is to provide the patient with blood pressure monitoring means that can record the blood pressure in memory and then transfer the recorded data to the physician. There are known automatic digital blood pressure monitors such as the UA-767 Automatic Digital Blood Pressure Monitor from A&D Company Limited. This 25 monitor is an oscillometric blood pressure measurement device for hospitals and private use. This device measures and displays blood pressure and heart rate in automatic mode calibrating itself, inflating and deflating the cuff and then automatically turning off itself. Only the one last measurement can be displayed because the monitor does not have data memory. Upon completion of each WO 01/26544 PCT/AUOO/01234 2 measurement, the UA-767 transmits 5 bytes of measure values to a built in serial interface on its main printed circuit board. It would be advantageous to provide a blood pressure monitoring apparatus which provides real time or delayed transmission of recorded blood pressure data to a 5 remote monitoring location, such that it can be collated and analysed and reported to a physician, by providing a memory for multiple storage and to provide the device with a data uploading function so that date and time of each recording can be transmitted to a remote monitoring station. Hitherto, it has not been possible to provide blood pressure data to remote 10 monitoring locations as the sampling of the data and displaying of the data does not lend itself to being converted into the appropriate signals to be transmitted by transtelephonic means. There has not been a desire or need in the past to display the data acquired through blood pressure monitoring in a similar method as other physiological data. 15 OBJECT OF THE INVENTION It is an object of the present invention to provide a blood pressure monitoring apparatus which substantially overcomes or ameliorates the above mentioned disadvantages. At the very least, the object of the invention is to provide an alternative to known blood pressure monitoring and display apparatus. 20 DISCLOSURE OF THE INVENTION According to one aspect of the present invention there is disclosed a transtelephonic blood pressure monitoring apparatus having a blood pressure monitor and a blood pressure sensor means, said monitor including a blood pressure acquisition and memory means, a control means, a transducer means 25 and output means, wherein said blood pressure acquisition and memory means receives blood pressure data from said sensor means and either sends said blood pressure data in real time to said transducer means which converts data into transmission signals to said output means or stores said blood pressure data in WO 01/26544 PCT/AUOO/01234 3 said memory means for delayed transmission to said transmission means, said control means controlling the operation of said apparatus. Preferably the apparatus also includes a display means display means for displaying either in real time or from the memory means the blood pressure data 5 which is acquired. Preferably the transducer means converts the data into signals which are sent to a speaker output as audio signals which are preferably transmitted over a telephone network to a remote receiving station which decodes and analyses the received audio signals. 10 In other preferred forms of the invention, the apparatus also comprises other physiological sensors such as ECG, SA02, temperature, etc and corresponding signal acquisition and amplifying means. In such forms, the apparatus uses the control means, transducer means and output means to transmit the corresponding data to a remote location via the 15 telephone network. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be now be described with reference to the accompanying drawings in which: Fig. 1 is a schematic block diagram of the apparatus of the present invention. 20 BEST MODE OF CARRYING OUT THE INVENTION A blood pressure monitoring apparatus 10 is illustrated in the drawing. The apparatus 10 includes a blood pressure monitor 11 which has a blood pressure sensor cuff (not illustrated) connected thereto and a transtelephonic controller 12. The monitor 11 uses the auto-inflate cuff to record blood pressure from the upper WO 01/26544 PCT/AUOO/01234 4 arm, wrist or finger of the patient, where the data is received by a blood pressure transducer 13 contained within the monitor 11. The pressure transducer 13 is connected to a microprocessor 14 which receives signals from the transducer 13, analyzes the received data and displays measured 5 blood pressure on a display 15. A power supply 16 supplies power to the microprocessor 14 and the display 15. The blood pressure monitor 11 is activated by a pushbutton 17 "START". The monitor 11 calibrates itself and starts measurement routines. A signal 18 which is acquired is pulled high at this stage and held high by the microprocessor 14 until 10 measurement is complete. After completion of the measurement, the monitor 11 displays the results on the display 15 and outputs measured values via a serial interface comprised of two signals; signal 19 being a serial clock output and signal 20 being a serial data output. Protocol of the transmission is compatible with well known Serial Peripheral Interface (SPI). 15 Transtelephonic functionality is implemented by the transtelephonic controller 12 which is made up of a microcontroller 21, serial memory 22, pushbutton 23 and speaker 24. The transtelephonic controller 12 is connected to the monitor 11 by a connector 25. The transtelephonic controller 12 is activated either by the acquired signal 18 from 20 the monitor 11 for a new data recording or by the pushbutton 23 for data transmission, ie uploading. When the transtelephonic controller 12 is activated by the signal 18, it waits for serial clock signal 19 and serial data output signal 20. Five bytes are transmitted by the microprocessor 14 to the transtelephonic controller 12 via SPI signals 19 and 20 and recorded into memory 22. When the 25 transtelephonic controller 12 is activated by the pushbutton 23, the transtelephonic controller 12 reads the recorded data from memory 23, converts the recorded data into corresponding audio tones and outputs frequency modulated data via the speaker 24 for acoustically coupled transmission of recording via a telephone network to a remote receiving station (not illustrated).
WO 01/26544 PCT/AUOO/01234 5 The remote receiving station preferably automatically decodes and analyses the frequency modulated audio signals and creates a report to a physician as required. Technique of encoding and decoding of analogue and digital data can be implemented in different forms such as frequency or phase modulation, dual tone 5 multi-frequency etc. The apparatus 10 also includes as preferable features, other physiological sensors 17 such as ECG, SAO2, temperature, etc, whereby the corresponding acquired signals are amplified and conditioned and supplied to the transtelephonic controller 12 for transmission to the remote receiving station. 10 The foregoing describes only one embodiment of the present invention, and modifications obvious to those skilled in the art can be made thereto without departing from the scope of the present invention.