Medical patient vital signs-monitoring apparatus

A portable multiple-vital signs monitor unit of the described apparatus is of ultra-light weight, e.g. less than one pound. In its preferred embodiment, the portable unit takes the form of a right parallelepiped enclosure the volume of which is only approximately 40 in.sup.3 having operator display and control panels and body lead jacks on its face and periphery, respectively, and providing wireless remote full-function communication with an in situ base unit with which the portable monitor may optionally be docked. The base unit communicates via a single telephone line with a remote, typically central location including a host computer and a health care provider, preferably via concurrent voice and data transmission. In its preferred embodiment, the invented apparatus includes in the portable unit the capability for diagnostic quality ECG and pulse oximetry monitoring and in its base unit the capability diagnostic quality blood pressure monitoring.

TECHNICAL FIELD 
The present invention relates generally to vital signs-monitoring 
apparatus. More particularly, it concerns apparatus including a portable, 
diagnostic-quality, multiple vital signs medical patient unit of extremely 
low mass that is easily transported by an ambulatory patient or nurse 
practitioner in a home or patient care facility and that is conveniently 
docked in a relatively fixed base unit. 
BACKGROUND ART 
Conventionally, multiple vital signs monitors are installed and used at 
fixed locations, bedside, in clinics and hospitals. They typically are not 
battery-operated, requiring instead power and input/output (I/O) cords and 
cables, and are made to be affixed to a bedside or other bedside 
equipment. Often, such multiple vital signs monitors are bulky, e.g. 
weighing up to one hundred pounds, and thus are impossible or at least 
very difficult to transport more than a few feet by hospital staff or 
contractors. 
Conventional single vital sign monitors may be portable and relatively 
lightweight, but provide limited versatility, permitting the monitoring of 
only one patient vital sign, e.g. ECG (e.g. as measured by skin-contact, 
resistance-measuring electrodes) or blood pressure (preferably 
non-invasive BP--e.g. as measured by an inflatable, limb-encircling, 
artery-occluding pressure cuff) or blood-oxygen level (e.g. as measured by 
pulse oximetry or SpO.sub.2), which it will be appreciated by those of 
skill in the art require relatively low bandwidths to provide diagnostic 
quality data. Known portable ECG monitors support only three-lead ECG 
monitoring, which is less reliable than twelve-lead monitoring. Some 
single vital sign monitors provide for real-time telemetry to a remote 
location of such monitored data, but do not provide for local, integral 
storage of such vital sign data for later outplay. By real time, it will 
be appreciated that minimization of the time delay between the talking of 
a patient vital sign measurement and the receipt thereof in usable form at 
a remote site by a physician or diagnostic technician is needed for 
high-quality patient care, and that such delay or latency preferably is on 
the order of a second, and preferably far less, and is no more than a very 
few seconds. 
U.S. Pat. No. 5,333,616 entitled WRIST-WORN ECG MONITOR describes such a 
portable ECG monitor; U.S. Pat. No. 4,967,756 entitled BLOOD PRESSURE AND 
HEART RATE MONITORING METHOD AND APATUS describes such a BP monitor; 
and co-pending U.S. patent application Ser. No. 08/556,468 entitled 
CONCURRENT MEDICAL PATIENT DATA AND VOICE COMMUNICATION METHOD AND 
APATUS, issued Jan. 6, 1998, as U.S. Pat. No. 5,704,364, describes 
tele-monitoring over the public switched telephone network (PSTN). All are 
commonly owned herewith, and the disclosures of these patents and this 
application are incorporated herein by this reference. 
DISCLOSURE OF THE INVENTION 
Briefly, the portable multiple-vital signs monitor unit of the invented 
apparatus is designed and constructed to be ultra-light weight, e.g. less 
than one pound, yet without compromising utility and versatility in 
real-time, remote, medical patient diagnostic and prescriptive care. In 
its preferred embodiment, the portable unit takes the form of a right 
parallelepiped enclosure the volume of which is only approximately 40 
in.sup.3. The battery-operated, portable unit preferably includes operator 
display and control panels and body lead jacks on its face and periphery, 
respectively, and provides remote fill-function communication with an in 
situ base unit with which the portable monitor may optionally be docked. 
The base unit communicates via a single switched telephone line with a 
remote, typically central, location including a host computer and a health 
care provider, preferably via concurrent (or at least synchronized, e.g. 
time-stamped) voice and data transmission. 
In its preferred embodiment, the invented apparatus includes the capability 
for diagnostic quality ECG and pulse oximetry monitoring in its portable 
unit and the capability for diagnostic quality blood pressure monitoring 
in its base unit. Diagnostic quality, as used herein, refers to 
high-quality data that may be relied upon by professional medical 
providers for diagnostic and prescriptive patient care, as may be defined 
by industry and/or regulatory standards such as ANSI/AAMI EC-11, EC-13 and 
EC-38 for ECG, EC 1099 for SpO.sub.2 and ANSI/AAMI SP10 for BP. 
Distinguished from diagnostic- quality vital signs data are data that are 
of insufficiently high resolution, integrity or continuity as to render 
the data informative and thus perhaps useful by medical and industry 
standards for general patient status monitoring but not useful for 
real-time diagnostic and prescriptive medicinal practice. 
These and additional objects and advantages of the present invention will 
be more readily understood after consideration of the drawings and the 
detailed description of the preferred embodiment which follows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE OF CARRYING 
OUT THE INVENTION 
Referring first to FIG. 1, invented apparatus 10 may be seen in the form of 
a system block diagram to include a portable, lightweight multiple-vital 
signs monitor 12 docked in a relatively fixed base unit 14. In its 
preferred embodiment, monitor 12 provides for both twelve-lead ECG and 
pulse oximetry (SpO.sub.2) monitoring of an ambulatory patient indicated 
in solid outline. Base unit 14 preferably provides for blood pressure 
monitoring of a seated or reclining patient. Base unit 14 preferably is 
connected via the public switched telephone network (PSTN) indicated at 
16, and two MODEMs, for concurrent voice and data transmission and 
reception with a central or host computer 18. 
Those of skill will appreciate that any plurality of patient vital signs 
may be monitored in accordance with the invention. Such vital signs may 
include, for example, electroencephalograph (EEG), ECG, blood-oxygen 
level, BP, blood-glucose level and blood flow and/or volume, as well as 
others, may be monitored, and may be communicated to a central computer 
either in the form of discrete numeric data (as in the case of static 
SpO.sub.2, BP and blood-glucose level data) or continuous waveform data 
(as in any case wherein relatively short-term aberrations may be important 
and it is desired to overview relatively raw, continuous data that has not 
been averaged or otherwise reduced, compacted or interpreted by the 
patient-connected monitoring equipment, e.g. EEG, ECG, auscultatory, 
blood-oxygen, plethysmographic, waveform data). Any and all such plural 
vital signs monitoring and communication of data representative thereof in 
any suitable form are within the spirit and scope of the invention. 
It will be appreciated that communication between portable monitor 12 and 
base unit 14 may be by radio frequency (RF), infrared or any other 
suitable wired or wireless communication means, alternative or additional 
to the mating electrical contact that is provided in accordance with the 
preferred embodiment of the invention. It will also be appreciated that 
communication between base unit 14 and central computer 18 (refer to FIG. 
1) may be performed by any suitable means including, e.g. cellular, 
satellite, etc., and in accordance with the teachings of the 
above-referenced U.S. patent application Ser. No. 08/556,468, now U.S. 
Pat. No. 5,704,364, or any other suitable communications protocol. 
Finally, it will be appreciated that portable monitor 12 alternatively may 
communicate directly with central computer 18, thus bypassing base unit 
14, e.g. by the provision of an internal modem within portable monitor 12 
and a suitable telephone line jack for PSTN connection, as will be 
described in more detail below by reference to FIGS. 3 through 7. 
FIG. 2 shows how conveniently portable monitor 12 may be docked in base 
unit 14 for certain vital signs monitoring and vital signs data and voice 
communication with central computer 18. It will be appreciated that, in 
accordance with the preferred embodiment of the invention, base unit 14 
effectively acts as a speakerphone for voice communication between a 
patient and a remote health care provider, while also communicating vital 
signs data to a central site for patient monitoring and diagnosis. 
Turning collectively now to FIGS. 3 through 7, portable monitor 12 will be 
described in detail. Portable monitor 12 may be seen preferably to include 
a housing 20 and a vital signs monitoring mechanism indicated generally at 
22 contained therein. Monitoring mechanism 22 may be seen from FIG. 6 to 
provide for the tracking of two or more medical patient vital signs, e.g. 
ECG and blood-oxygen level, in the form of diagnostic quality signal 
representations stored in a memory device also located preferably within 
housing 20 and preferably forming a part of monitoring mechanism 22. It 
will be appreciated that any two or more medical patient vital signs may 
be monitored, within the spirit and scope of the invention, to produce 
multiple patient vital signs in the form of diagnostic quality signal 
representations in accordance with accepted industry or regulatory 
standards. 
In accordance with one important aspect of the invention, portable monitor 
12, including its batteries, preferably has an overall weight of less than 
approximately two pounds (lb) (0.74 kilograms (kg)), more preferably has 
an overall weight of less than approximately 1 pound (lb) (0.37 kg), and 
most preferably has an overall weight of less than approximately 15.7 
ounces (oz) (0.36 kg), thereby rendering portable monitor 12 extremely 
lightweight and convenient to use for multiple-vital signs diagnostic 
medical patient monitoring. Preferably, housing 20 is injection molded 
from an impact-resistant, lightweight material such as polycarbonate. 
Reference to FIGS. 3 through 5, 7A and 7B points out another important 
feature of portable monitor 12: The overall external volume of portable 
monitor 12, including batteries, preferably is less than approximately 100 
cubic inches (in.sup.3) (1.63 liters (l)), more preferably is less than 
approximately 60 in.sup.3 (0.975 1l) and most preferably is less than 
approximately 40 in.sup.3 (650 milliliters (ml)). The relatively small 
volume is achieved by choice of circuit topology, patient interface 
controls and indicators and I/O ports, while the relatively low weight is 
achieved by these choices as well as choice of materials, as will be seen. 
Portable monitor 12 preferably includes a twelve-lead ECG jack in the form 
of a printed circuit board (PCB) edge-type connector; a pulse oximetry 
serial I/O jack; a PCB-type edge connector for base unit input/output 
(I/O) and portable monitor battery recharging; and a third, expansion 
port, e.g. a PCMCLA port that may be used for diagnostics and/or equipment 
maintenance, for direct remote connect via modem or for cellular or local 
area network (LAN) connection. Although BP electronics and software 
preferably are in portable monitor 12, the BP I/O port may be seen to be 
in base unit 14. This is because of the bulk and power requirements of the 
BP cuff-pressurizing pump motor and because a seated, relaxed patient has 
been found to be important to BP trend analysis and diagnosis. Of course, 
those of skill in the art will appreciate that, within the spirit and 
scope of the invention, the BP pump motor alternatively could be placed 
within the portable monitor's enclosure. 
Referring briefly now to FIG. 2, it is noted from the isometric view of 
apparatus 10 that portable unit 12 is configured for mating support on and 
partly within base unit 14. It will be appreciated that in such a mated 
configuration, portable unit 12 may be recharged by base unit 14 and that 
other patient vital signs monitoring may be accomplished. For example, in 
accordance with the preferred embodiment of the invention, BP monitoring 
may be performed on the patient while the patient is seated, as it is 
believed that BP monitoring is more accurate when the patient is in 
relative repose. Base unit 14 thus preferably is equipped with an 
inflatable BP cuff 24 at the end of an air hose 26 and a base 
unit-integral pump 28 (shown in FIG. 2 only fragmentarily) operatively 
connected thereto for inflating and deflating the cuff. 
Base unit 14 also preferably may supply power for recharging one or more 
batteries, e.g. four AA alkaline batteries, within portable monitor 12, 
and may have an I/O port 30 for supplying signal input and output to and 
from portable monitor 12. In accordance with the preferred embodiment of 
the invention, the electronics associated with obtaining diastolic, 
systolic and mean BP data (as well as pulse data) from BP cuff 24, with 
temporarily storing such data and with communicating such data to a remote 
computer in a monitoring and patient care facility is located within 
portable monitor 12, although it will be appreciated that such electronics 
may be placed any suitable location within apparatus 10, within the spirit 
and scope of the invention. 
Base unit 14 in its preferred embodiment provides such I/O port 30 via a 
printed circuit board (PCB) edge connector having a suitable number of 
finger-like contacts, e.g. thirty, for mating a corresponding I/O port 32 
in a base region of portable monitor 12 (refer briefly to FIGS. 6 and 8). 
Preferably, base unit 14 continuously and automatically trickle charges 
one or more batteries within portable monitor 12 while the latter is 
properly docked in the former, thus requiring minimal patient effort. 
Those of skill will appreciate that such is similar to portable phones, 
which typically are recharged any time they are properly docked in their 
AC-coupled home bases. It will also be appreciated that portable monitor 
12 is fully functional as a multiple-vital signs monitor even when it is 
docked in base unit 14. Thus, in accordance with the invention, plural 
vital signs monitoring may be accomplished while the patient is seated 
near the base unit, including at least diagnostic-quality ECG, blood 
oxygen and blood pressure. 
Referring now to FIGS. 3 through 5, portable monitor 12 may be seen, 
respectively, in front, side and end elevations. These elevations of 
portable monitor 12 illustrate the compactness of portable monitor 12 as 
well as its low-mass versatility in providing convenient, portable, 
multiple patient vital signs monitoring. It may be seen that portable 
monitor 12, in accordance with a preferred embodiment of the invention, is 
a right parallelepiped measuring approximately 6.18" (15.7 cm) in height 
H, 4.14" (10.5 cm) in width W and 1.2" (3.05 cm) in depth D except in a 
rear battery pack region where monitor 12 measures approximately 1.68" 
(4.27 cm) in depth D'. The sleek design renders portable monitor 12 
readily grasped in the patient's hand, and easily slipped into a shirt, 
blouse, pants or robe pocket for ambulatory use or a provided carrying 
case. 
It will be appreciated from FIGS. 2 through 5 that portable monitor 12 is 
smoothly rounded at its comers and edges, and has an overall aesthetic 
appeal. Moreover, it may be seen that the I/O ports to which cables are 
connected when monitor 12 is in use are conveniently located on edge 
surfaces of the monitor's housing, whereas the display and pushbuttons 
including the prominent RECORD button are conveniently located on the 
front surface of the housing, rendering the portable monitor easy to use 
during an ambulatory monitoring and diagnostic session. Because of its 
modest size, modular construction, the architecture of the electronic 
circuitry therein and the choice of materials used in its fabrication and 
assembly, monitor 12 weighs in at just under one pound, making it a 
featherweight compared to prior art multiple vital signs monitors. This 
high functional density in a multiple vital signs monitor--wherein 
functionality is relatively high but size and mass are relatively low--is 
one of the key advantages of the invention. 
Referring next briefly to FIG. 6, a detailed schematic block diagram of 
portable monitor 12 illustrates the circuit and functional partitioning 
that renders possible the production of an extremely low-mass multiple 
vital signs monitor. Portable monitor 12 preferably includes a keyboard 
preferably in the form of a set of pushbutton switches 34, a dot matrix 
display 36, an annunciator preferably in the form of a buzzer or beeper 
38, various I/O ports such as a pulse oximetry data serial port 40, a 
multi-lead ECG port 42, a PCMCIA or PC-Card port 44, a docking module I/O 
port 32 and power supply-powered electronic circuitry 46 within integral 
housing 20 indicated in rectangular outline. Electronic circuitry 46 is 
illustrated schematically and will be described in some detail in 
mediately below. 
Electronic circuitry, or electronics, 46 preferably includes a 
microprocessor ("CIRRUS 7110") 48 and associated crystals ("XTALS") 50; an 
SpO.sub.2 device or unit ("SPO2 ELECTRONICS") 52, e.g. the OEM device made 
by Nonin; RS-232 I/O port driver/receiver circuitry ("DRIVERS") 54; a dual 
universal asynchronous receiver/transmitter ("DUART") 56; a 2 megabyte 
(MB) flash memory 60; a PCMCIA interface ("IFC") 62; a 512 kB dynamic 
read-and-write memory (DRAM) 64; a watchdog timer ("WATCHDOG") 66; a 
first-in/first-out (FIFO) memory 68 for pacing the asynchronous, 
continuous ECG waveform data samples; an ECG receiver ("RCVR") circuit 70; 
an ECG, field-effect (FE) gate array 72; ECG front-end analogue circuitry 
74; power supplies 76; and miscellaneous so-called `glue` circuitry 78, 
e.g., in the form of a complex programmable logic device ("CPLD"). 
Microprocessor 48 preferably integrally includes a central processing unit 
("ARM7 CPU"), clocks, a general-purpose I/0 interface (GPIO), a serial 
port ("SERIAL"), a real-time clock (RTC), power management circuitry 
("POWER MNGMT"), various counters/timers, an I/O bus interface ("BUS 
IFC"), a DRAM controller ("DRAMC"); interrupt control circuitry ("INTS"), 
PC-Card control and an LCD interface ("LCD IFC") such as that found in a 
Cirrus 7110 processor. Housing-integral power supplies 76 preferably 
provide a rechargeable bank of four standard, series-connected AA alkaline 
batteries--as well as a backup ("B.U.") lithium battery that powers 
essential functions such as the RTC when one or more of the alkaline 
batteries is being replaced--and appropriate regulation circuitry for all 
of the electronics and other I/O devices housed within portable monitor 
12. 
Preferably, two different types of batteries form a part of power supplies 
76. Preferably, a first type of battery, e.g. alkaline, provides for the 
relatively high-current, short-life, requirements of portable monitor 12 
and a second type of battery, e.g. lithium, provides for the relatively 
low-current, long-life, requirements thereof. For example, the chosen 
battery type, mix and number preferably may provide portable monitor 12 
with the capacity to perform constant monitoring and periodic, e.g. 
on-demand, reporting for at least twenty-four hours as well as active, 
e.g. on-demand, monitoring and reporting for up to two weeks, both without 
needing recharging. Thus, it will be appreciated that power supplies 76 
provide portable monitor 12 extended operation independent from base unit 
14 in accordance with the preferred embodiment of the invention. 
It is noted that the four AA alkaline batteries weigh approximately 3.4 oz 
(0.078 kg) total, so it will be appreciated that the alkaline batteries 
presently contribute significantly (more than 20%) to the overall weight 
of portable monitor 12. It is contemplated, then, that by the use of 
alternative battery cell types, e.g. a lithium ion or similar 
high-current, long-life disk battery, the weight of the batteries and thus 
of portable monitor 12 may be further reduced, within the spirit and scope 
of the invention. Similarly, it is contemplated that the volume of such 
high-current, long-life batteries may be reduced commensurately with their 
mass, also within the spirit and scope of the invention, thereby further 
increasing the functional density of the invented apparatus. Nevertheless, 
even with the preferred AA alkaline battery design represented in the 
preferred embodiment of the invention, the housing and monitoring 
mechanism which includes the power supplies' batteries integrally 
contained therein weighs a mere 15.7 oz, providing remarkable high 
functional density in a multiple vital signs monitor. 
Referring briefly to FIG. 2, the human interface between portable monitor 
electronics 46 and the medical patient or other user thereof thus will be 
understood to include keyboard 34 preferably including plural, e.g. five, 
pushbutton switches 78, 80, 82, 84, 86 including the prominent RECORD 
switch 86 centered in the lower front surface of the housing; display 36 
which preferably may be a 320.times.240 reflective dot matrix monochrome 
display having a (0.3 mm) 12 mil dot pitch, thus enabling AAMI monitoring 
resolution requirements for at least three leads of simultaneous, 
real-time ECG or EEG or other continuous, high-resolution waveform data; 
and buzzer or beeper 38. Firmware resident within flash memory for at 
least three leads of simultaneous, real-time ECG or EEG or other 
continuous, high 60--in cooperation with the ARM7 CPU, the DRAMC and the 
GPIO--polls the keyboard, updates the display and signals the buzzer to 
communicate with the patient before, during and after an ambulatory or 
stationary monitoring session. 
Referring again now to FIG. 6, it will be appreciated that most of the 
cooperative components are stock, rather than custom, chips or integrated 
circuits (ICs) and circuit modules that are readily available from various 
manufacturers and mounted, very simply, on a singular multi-layer PCB (not 
shown in FIG. 6, but shown in FIG. 7B to be described below). Yet the 
architecture of electronics 46 renders the electronic circuitry and 
hardware within portable monitor 12 straightforward and relatively 
inexpensive to manufacture and maintain while providing great versatility 
in multiple patient vital signs monitoring. Importantly, the architecture 
represents a desirable tradeoff between processing power on the one hand 
and power consumption and cost--including hardware and firmware 
development costs and assembled and tested monitor costs--on the other. 
Exemplary of the way in which development and recurring costs are minimized 
are the stability and support available from the manufacturers of some of 
the stock components described above. The Cirrus 7110 processor is a 
mature OEM product characterized by a low-power requirement and 
high-powered support including software simulation and development system 
and operating system support. Similarly, SpO.sub.2 electronics device 52 
manufactured by Nonin is a mature OEM product characterized by a 
straightforward, relatively low-speed serial interface in the form of a 
hybrid circuit module that is easily plugged into a motherboard. 
Similarly, the ECG RCVR circuit 70 and FE gate array 72, manufactured by 
Mortara are mature, off-the-shelf modules and components that are easily 
interfaced with and integrated into a PCB or motherboard. Finally, it will 
be appreciated that PCMCIA interface 62 manufactured by a wide variety of 
manufacturers-an interface that is now nearly ubiquitous in connection 
with personal computers (PCs)--is a very mature and versatile product from 
the standpoint of ease of manufacture, use and maintenance. 
Indeed, the provision of a PCMCIA interface, or PC-Card, in a portable 
multiple vital signs monitor creates a plethora of additional features. 
Standard applications of PCMCIA in the PC industry may be imported to the 
invented vital signs monitor, including use of it as extended flash 
(electronic) or rotating (magnetic or optical) memory or other mass 
storage medium, a local area network (LAN) connection, a digital cellular 
wireless communications interface, a SCSI interface, a modem with phone 
jack, a data acquisition card, a high-speed parallel interface or the 
like. 
Those of skill in the art will appreciate also that wireless 
transtelephonic multiple vital signs data communication capability may be 
provided to the portable monitor by way of an integral modular controller 
interface, e.g. a PCMCIA having an oscillator, a modulator and a suitable 
speaker. In accordance with the preferred embodiment of the invention, the 
PCMCIA may be used as the interface through which flash memory is loaded 
with production firmware, through which firmware updates are made and 
through which diagnostics and troubleshooting are performed during 
manufacture and field servicing of the portable monitor. Myriad other 
applications are possible, and all are within the spirit and scope of the 
invention. 
Briefly, the firmware resident within flash memory 60, in accordance with 
the preferred embodiment of the invention, controls the I/O ports, manages 
memory allocation including the buffers within DRAM 64 in the well-known 
looping memory manner by which only recent waveform data of interest is 
accessible for diagnostic purposes and older data not of interest is 
recorded over, handles communication with docking unit 14 or an optional, 
external printer or other data communications equipment (DCE) or data 
terminal equipment (DTE), polls the keyboard by debouncing the switches 
and detecting closures, updates the dot matrix display and minimizes power 
consumption without loss of vital data. 
Those skilled in the art will appreciate how straightforwardly BP, blood 
oxygen level, ECG, pacemaker or defibrillator pulses, EEG and other vital 
signs represented by analogue signals may be filtered, pacemaker pulses 
may be detected, characteristic complexes may be sampled, as by 
over-sampling plural samples, optionally averaging the plural samples and 
decimating the samples to produce for storing or recording in a memory 
device digitized representations of an ECG or EEG waveform of diagnostic 
quality in memory for later outplay. It will be appreciated that 
decimation is used in its broadest sense to refer to a process whereby 
only a pertinent periodic portion, or fraction, of a sampled vital sign is 
used in vital signs monitoring. Recorded samples may be stored in 
so-called looping memory such that only pertinent data around a 
significant trigger event consumes memory. Recorded samples may be 
time-stamped, using the RTC, in order to render waveform data meaningful 
even in the event of a temporary data dropout or other interruption, thus 
avoiding misinterpretation of fragmented vital signs data. 
Such may be done, for example, in accordance with the teachings of commonly 
owned U.S. Pat. No. 4,958,641 entitled HEART DATA MONITORING METHOD AND 
APATUS issued Sep. 25, 1990; U.S. Pat. No. 4,977,899 entitled HEART 
DATA MONITORING METHOD AND APATUS issued Dec. 18, 1990; U.S. Pat. No. 
5,012,814 entitled IMPLANTABLE-DEFIBRILLATOR PULSE DETECTION-TRIGGERED ECG 
MONITORING METHOD AND APATUS issued May 7, 1991; U.S. Pat. No. 
5,128,552 entitled SYSTEM AND METHOD FOR POWER SUPPLY PRESERVATION IN A 
PERSONAL HEALTH MONITOR issued Jul. 7, 1992; U.S. Pat. No. 5,317,269 
entitled WRIST-WORN ECG MONITOR WITH BATTERY END OF LIFE PREDICTION issued 
May 31, 1994; U.S. Pat. No. 5,351,695 entitled WRIST-WORN ECG MONITOR 
issued Oct. 4, 1994; and U.S. Pat. No. 5,613,495 entitled HIGH FUNCTIONAL 
DENSITY CARDIAC MONITORING SYSTEM FOR CAPTURED WINDOWED ECG DATA issued 
Mar. 25, 1997, the disclosures of which are incorporated herein by this 
reference. 
FIG. 6 shows in schematic block diagram form and in phantom connection with 
the BUS IFC some of the vital signs sensors that may be incorporated into 
apparatus 10, within the spirit and scope of the invention. For example, 
plethysmographic data may be sampled and recorded via a plethysmographic 
sensor 88; auscultatory data may be sampled and recorded via an 
auscultatory sensor 90; blood-glucose level data may be sampled and 
recorded via a blood-glucose level sensor 92; electroencephalographic 
(EEG) data may be sampled and recorded via an EEG sensor 94; etc. in 
addition to or instead of the sampling and recording of ECG, blood-oxygen 
level and BP data as described and illustrated herein with respect to the 
preferred embodiment of the invention. Those of skill in the arts will 
appreciate that any two or more vital signs concurrently may be monitored, 
recorded and outplayed either locally or remotely for oversight by medical 
personnel for diagnostic purposes, all within the spirit and scope of the 
invention. 
Referring now to FIGS. 7A and 7B, it may be seen how the component parts of 
invented portable monitor 12--which forms part of invented apparatus 
10--fit together, by way of an exploded assembly drawing of the portable 
monitor. FIG. 7A shows portable monitor components including a top case or 
molded face plate 96; menu pushbuttons 78, 80, 82, 84 and RECORD 
pushbutton 86 that make up keyboard 34 liquid crystal display; and LCD 
window 98, which collectively may be seen to form the front half of 
housing 20. Below display window 98 is LCD 36 and below that is an LCD 
bracket 100. It will be appreciated that the components shown in FIG. 7A 
all fit snugly together, with microstrip pushbuttons 78, 80, 82, 84 and 
discrete pushbutton 86 fitting within recesses formed in the front surface 
of face plate 96 and with LCD 36, window 98 and bracket 100 fitting within 
a recess formed in the rear surface thereof. 
FIG. 7B shows a printed circuit board PCB 102 with PC edge connector or 
base unit I/O port 32, twelve-lead ECG connector shroud 104 that forms a 
part of ECG port 42 and a right-angle DB9 female connector 106 that forms 
a part of SpO.sub.2 serial port 40. Visible therebeneath for PCB 102 
mounting is a PCMCIA surface-mount technology (SMT) connector 108 and a 
corresponding PCMCIA plug-in cover 110. Also visible therebeneath are dual 
power contacts such as contact 112 for connecting piezoelectric buzzer 38 
and the alkaline batteries with the circuitry of PCB 102. Also visible 
therebeneath is SPO.sub.2 unit 52 for piggy-backed mounting and connection 
to PCB 102. Therebeneath is a bottom case or molded back plate 114 and 
laterally spaced therefrom is an alkaline battery module 116 for holding 
four AA alkaline batteries such as battery 118 and for supplying power 
therefrom to circuitry on PCB 102 via various positive, negative and 
inter-battery contacts 120, 122, 124. 
Referring collectively to FIGS. 7A and 7B, it may be seen that nine screws 
such as screw 126 and two locknuts with washers such as locknut 128 secure 
various components together with a minimum of hardware. Finally, it may be 
seen that one or more product labels such as labels 130, 132 may be 
affixed to portable monitor 12, as indicated. It will be appreciated that 
certain details of construction are omitted in FIG. 7B for the sake of 
clarity. Discrete electrical components such as crystals, decoupling 
capacitors, resistors, test pins, etc. mounted on PCB 102 are not shown, 
nor are the signal traces in the multiple layers of the PCB. 
PCB fabrication and circuit design may be accomplished in any suitable 
manner consistent with low mass and electromechanical integrity. It will 
be appreciated that, in accordance with the preferred embodiment of the 
invention, hardware and component counts are minimized to lower cost, to 
facilitate assembly and to reduce weight. It will also be appreciated that 
circuit and device emissions preferably are minimized by circuit design 
and PCB routing and layup (e.g. by the use of thin layers and integral 
power and ground distribution planes) techniques that do not add weight. 
The highest scale circuit integration is preferred to minimize component 
count, the lowest power devices are chosen, e.g. CMOS devices that will 
work at 3.3V and only essential circuitry is powered, all in order to 
minimize power consumption and to reduce the power supplies' battery 
weight. Connector weight is minimized by using, wherever possible, printed 
circuit edge connectors requiring little or no on-board hardware. 
Importantly, the battery module is rendered easily reconfigured by its 
snap-fit, `outboard` design, thereby providing an upgrade path to 
different and preferably lower-mass battery types as such become 
available. 
Referring finally to FIG. 8, and for the sake of completeness, a schematic 
block diagram of docking module 14 illustrates the functional blocks that 
enable the docking module to communicate with portable monitor 12 via an 
RS-232 I/O port and with a remote host computer (not shown, but of 
conventional design and providing for bi-directional, simultaneous voice 
and data communication between the monitored patient and a medical 
technician) via a PSTN communication port. 
Base or docking module 14 preferably includes a oscillometric BP 
electronics 134 (including pump 28 of FIG. 2 not shown) and associated 
cuff air hose 26 for connection with air inlet/outlet port on inflatable 
BP cuff 24; an RS-232 I/O port 30 for operative communication with 
portable monitor 12; an OEM V.34 digital simultaneous voice/data (DSVD) 
fax/modem circuit 136 and associated PSTN I/O port 138; an RS-232 DB9 
printer I/0 port 140; a printer/DSVD control line 142 from portable 
monitor 12 and an associated logic switch 144 controlled thereby to select 
whether monitor 12 is in communication with an external printer or the 
PSTN; an external, so-called power `brick`, or AC/DC power supply 146; a 
speaker ("SPKR") 148; and a microphone ("MIC") 150. Preferably, and as 
indicated by a broad, vertical dashed line, a patient-isolation barrier 
152 is provided within docking module 14 to meet regulatory requirements 
that a patient who may be connected to portable monitor 12 be safely 
isolated from the PSTN. 
It will be appreciated that alternative circuitry, or circuitry 
alternatively configured and/or partitioned, may within the spirit and 
scope of the invention be provided within docking module 14 to provide 
different and/or additional patient multiple vital monitoring capability. 
It will also be appreciated that the functional capability provided by 
invented apparatus 10 may be differently partitioned between portable 
monitor 12 and its associated docking module 14, all within the spirit and 
scope of the invention. 
METHOD OF USE OF THE INVENTED DEVICE 
It may be seen, then, that the invented monitoring system including the 
portable monitor received in a relatively fixed base is used to monitor or 
track a medical patient's vital signs and to communicate such vital signs 
in real time to a remote site for diagnostic and prescriptive purposes, 
i.e. with a minimum delay on the order of a second or less between the 
sample or measurement and the receipt thereof at the remote site. 
Preferably, such is done conveniently over a single switched telephone 
line or wireless link such as a digital cellular satellite link such that 
little or no extra equipment is required at the patient's site, which 
typically is the patient's home. Preferably, two-way voice communication 
also is provided between the patient being monitored in real time and the 
remote physician or care provider. Yet the base and portable monitor that 
collectively are referred to herein as the monitoring system each are 
small, lightweight and low-mass, and are easily and inexpensively 
manufactured and maintained. 
Accordingly, while the present invention has been shown and described with 
reference to the foregoing preferred apparatus, it will be apparent to 
those skilled in the art that other changes in form and detail may be made 
therein without departing from the spirit and scope of the invention as 
defined in the appended claims.