HK1083040B - Finger oximeter with remote telecommunications capabilities and system therefor - Google Patents

Description

Finger oximeter with remote communication capability and system based on the oximeter

Technical Field

The present invention relates to a finger oximeter, and more particularly, to a finger oximeter with telecommunications capability and a system for monitoring signals from the finger oximeter.

Disclosure of Invention

In co-pending U.S. application 09/940,418, assigned to the same assignee as the present invention, a finger oximeter is disclosed having a unique finger grip (finger grip) suspension system. The disclosed finger oximeter is a stand-alone device. The finger oximeter of the instant invention improves upon the stand-alone finger oximeter of the co-pending application by providing communication capability to enable the transmission of data from a patient to a remote device, such as a monitoring device, to enable remote monitoring of the patient.

In addition to the oximeter circuitry that controls the operation of the radiation emitter that sends a multi-frequency light to the finger and the sensor that senses the radiation passing through the finger to obtain data from the patient and then calculates the oxygen saturation level of blood from the obtained data, the oximeter of the instant invention further comprises a transmission circuit, which may be a radio frequency RF circuit, that cooperates with the finger oximeter circuitry to cause a signal, such as RF, to be transmitted to a remote device that contains the calculated oxygen saturation level of blood of the patient. The RF circuitry is disposed on a PC circuit board that is disposed on the housing of the finger oximeter along with another circuit board on which the finger oximeter circuitry and other circuitry, such as power supply circuitry and processor circuitry, are mounted. Instead of multiple printed circuit boards, a single circuit board that contains all of the circuitry of the RF transmitter mounted oximeter of the instant invention may be provided entirely within the housing of the finger oximeter.

Thus, the finger oximeter of the instant invention includes a housing having an opening through which a patient's finger may be placed; a radiation emitter disposed within the housing, the radiation emitter outputting multi-frequency radiation to the finger; a sensor disposed within the housing for monitoring radiation from the transmitter that passes through or reflects from a finger of the patient to obtain data relating to a physiological characteristic of the patient; at least one circuit disposed within the housing for operating the radiation emitter and the sensor, the circuit calculating at least the oxygen saturation level of blood of the patient from the acquired data; and another circuit disposed within the housing that transmits an RF signal, such as the calculated oxygen saturation level of the patient's blood, to a remote location.

The present invention also relates to a system wherein the RF signal transmitted by the finger oximeter is received by a remote device, such as a Vital Signs monitor (Vital Signs monitor) sold by the agency, where the device cooperates with a tuned RF receiver to receive the RF signal transmitted by the finger oximeter. The remote device may be provided with a transceiver to allow an observer at the remote monitoring device end to control the operation of the finger oximeter. This is performed by the observer at the remote monitoring system, who activates the switch that sends the signal to activate/deactivate the remote finger oximeter.

The RF signal transmitted by the finger oximeter may be transmitted in the form of data packets. An unpacking element, which may include a processing circuit and a converter circuit, is disposed on the remote monitoring device for unpacking the data packets and converting the unpacked data from digital signals to analog signals to enable the monitored physiological characteristics of the patient to be displayed on a display of the monitoring device. The transmission of the RF signal and the control of the finger oximeter by the remote monitoring device may be accomplished via a communication protocol such as bluetooth.

Drawings

The invention will become apparent and better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, in which:

FIGS. 1a-1d are various views of the finger oximeter of the instant invention, particularly its housing;

FIG. 2 is a finger oximeter circuit for operation of the finger oximeter of FIG. 1;

FIG. 3 is a transmission circuit working in cooperation with the oximeter circuit of FIG. 2 for transmitting the measured physiological characteristics of the patient to a remote unit;

FIG. 4 shows a Printed Circuit Board (PCB) with the circuit of FIG. 3 mounted thereon;

FIG. 5 is a perspective view of the upper half of the housing of the present invention with the cover removed showing the mounting of the finger oximeter circuitry of the present invention;

FIG. 6 is a block diagram illustrating the transmission of RF signals from the finger oximeter of the instant invention to a remote monitoring device;

FIG. 7 illustrates portions of a remote monitoring device of the system of the present invention; and

fig. 8 is a block diagram illustrating the interaction of the finger oximeter with a mounted remote monitoring device to control the operation of the finger oximeter of the instant invention.

Detailed Description

Fig. 1a-1d illustrate the housing of the finger oximeter disclosed in the co-pending application 09/940,418, previously described and incorporated herein by reference. The housing of the finger oximeter of the instant invention may have the same housing as that of the 418 application. Thus, finger oximeter 2, as shown in the plan view of FIG. 1a, has a display 4 that enables the finger oximeter to display various physiological characteristics of the patient, including, for example, the oxygen saturation level of blood (SpO) of the patient₂) Heart rate and blood pressure.

As shown in the front view of FIG. 1b, finger oximeter 2 is made up of two housing portions 6 and 8, wherein lower housing 8 is vertically movable relative to upper housing 6 in the direction indicated by arrow 10. The upper shell 6 is protected by a cover 12. Mounted on the upper housing 6 and protected by the cover 12 are a display and a circuit board, as shown in fig. 5. An opening 14 is formed between the upper and lower shells 6, 8. Each finger portion 6 and 8 is fitted with a finger pad which together form a finger gripping contour which is located or placed within opening 14. The finger pads mounted to the upper housing portion 6 and lower housing portion 8 are indicated at 16 and 18, respectively. The upper housing 6 and the lower housing 8 are vertically offset from each other by a number of springs, not shown, to ensure a secure grip of the finger in the opening 14 between them. The system for clamping a finger between the upper and lower housings 6, 8 of the finger oximeter 2 is described in detail in the aforementioned application 418.

With the finger oximeter of application 418, in order to read the blood oxygen concentration of the patient, a nurse or doctor must approach the patient in order to be able to read the display provided on the finger oximeter. And this is only accurate when one read at a given point in time is required. However, inclusion of SpO where the physician may not be always in the vicinity of the patient and the patient needs to be continuously monitored₂In the case of physiological characteristics of (a), it is desirable to remotely monitor data collected from a patient.

As shown in FIG. 1c, finger oximeter 2 has a rear side on which is mounted a switch 20 that enables the user to manually activate the device, i.e., by energizing the various circuits of the printed circuit board mounted in the housing of the finger oximeter. A battery module for powering the various components and mounted in the lower portion of the housing 8 is indicated at 22. Although the oximeter is shown as having switch 20 and display 4, the finger oximeter of the instant invention may be configured in practice to not include any display 4 or switch 20 if it is determined that both the operation of the finger oximeter and the monitoring of the patient's data obtained from the finger oximeter are remotely operated from the finger oximeter, although the patient would be wearing the finger oximeter.

FIG. 1d is a side view of the finger oximeter, showing cover 12 attached to housing 24.

FIG. 2 is a schematic diagram of the oximeter circuitry of the finger oximeter. For ease of discussion, the major functions of the circuit are grouped separately as functional circuits by dotted lines.

Within the housing, and in particular within the lower housing portion 8 of the finger oximeter embodiment of the present invention as shown in fig. 1a-1D, a light detector is provided (D1). Switch 20, designated SW1 in FIG. 2, is also provided on flexible strap 26 which is attached to the lower housing portion or lower finger grip 18 of the finger oximeter of the instant invention. When the switch is pressed, power is applied to the radiation emitter, which is formed by LEDs with different frequencies, which are part of the functional circuit 28. The multifrequency light from the LEDs is directed in radiation to the finger between the upper finger grip 6 and the lower finger grip 8 of the finger oximeter. Once the finger is removed from opening 16 and away from upper clip 6 and lower clip 8, microprocessor U1 will turn the device off after a predetermined period of time, for example, 8 seconds, to conserve power.

The flexible strip 26 is connected to the functional circuitry 30 by conventional connection means. Functional circuit 30 is an analog detector preprocessing circuit that measures the input current signal from the patient's finger, where the analog current signal is converted to an analog voltage signal. The analog voltage signal is amplified by operational amplifier U2C and outputs an amplified analog voltage signal VSIG. The dynamic range of the signal is controlled by the IC circuit U4, which acts as an integrated digital potentiometer.

The amplified analog voltage signal VSIG is input to input pin a2 of microprocessor U1. The analog voltage signal is converted into a corresponding digital signal by the processor U1 and output to the functional circuit 32, which is an LED driving circuit including driver IC circuits U8 and U9. Drive circuit 32 provides signals to the various digital DIGs 1-6 for displaying information collected from the patient on a display. If no display is provided on the finger oximeter of the instant invention, the functional circuitry 32 and LED display 4 may be removed from the circuitry. On the other hand, even though the measured physiological characteristics of the patient may be displayed remotely from the finger oximeter, both the display 4 and the functional circuitry 32 may be provided on the finger oximeter of the instant invention so that both the patient and the doctor may monitor the patient data.

Another functional circuit shown in FIG. 2 is functional circuit 28, which is a variable LED drive circuit that drives two LEDs that emit multi-frequency light to the patient's finger through an aperture provided in the upper half 6 of the finger oximeter. As with the finger pads 16, 18, the apertures provided on the upper and lower portions 6, 8 of the housing enable the multifrequency light from the light emitter LEDs to be directed at the finger, and the harmless (defused) light passing through the patient's finger to be detected by the photodetector D1. The resulting current signal detected by detector D1 is provided to analog detector pre-processing circuitry 30.

Functional circuit 34 is a switching power supply circuit that regulates the power supplied to the various elements of the oximeter circuit of fig. 2. Functional circuit 36 is a battery voltage divider circuit that discriminates whether the voltage of battery pack 22 is low.

Functional circuit 38 is a timing circuit for the various elements of the finger oximeter. The clock for microprocessor U1 is generated by circuit 38 through element U6A. If the voltage output is below 3 volts, the combined elements U6B and U6C ensure that there is sufficient voltage from the battery pack 22 to provide the appropriate clock signals to the various elements of the finger oximeter circuit of FIG. 2.

Fig. 3 is a diagram of the RF transmitter circuitry of the finger oximeter of the instant invention. In addition to ground, the RF transmitter circuit of FIG. 3 has an input, represented by DATA, connected to the SDI output, i.e., pin 24 of microprocessor U1 as shown in the circuit of FIG. 2. The circuit of fig. 3 is further connected by means of its input power +3.3VDC to the circuit of fig. 2, which is connected to the output of capacitor C21 of functional circuit 34 of the oximeter circuit of fig. 2. For the circuit of fig. 3, element 40 is a SAW ceramic resonator that determines the frequency of the RF signal output by the circuit of fig. 3. The frequency of the transmitter circuit may be selected by the user and adjusted to coincide with the receiver circuit of the remote monitoring device. Transistor Q1, labeled 42, acts as both an amplifier and an oscillator and, together with elements C2, L1 and C3, is used to output an RF signal to the antenna of the transmitter circuit represented by the loop of inductors L1, L2 and capacitors C4, C5. The power supply for the circuit is provided by 3.3 VDC.

The loop antenna 44 is shown in the printed circuit board 46 of fig. 4. It is noted that the components are etched and mounted on the circuit board 46 of fig. 4.

As best seen in FIG. 5, with cover 12 removed, the upper portion 6 of the housing 2 of the finger oximeter is shown to include display 4 and printed circuit board 48, on which printed circuit board 48 the various components of most of the oximeter circuitry of FIG. 2 are disposed. Mounted on one side of circuit board 48 is circuit board 46 having RF transmitter circuitry thereon. The illustrated circuit board 46 is attached to the side walls of the upper portion 6 and is fitted and retained therein by shoulders 50 which engage slots 52 (fig. 4) cut into the printed circuit board 46.

The system portion of the finger oximeter of the instant invention is shown in fig. 6. As shown, the patient data, once collected by the finger oximeter, is transmitted to the RF transmitter. There, the RF signal is transmitted over an RF link to a remote monitoring device, such as a vital signs monitor sold by the agent. In order to be able to receive RF signals from the RF transmitter, an RF receiver 52 is provided in the remote monitoring device. The device further comprises a data unpacking and displaying device 54. Upon receiving the RF signal, the RF receiver 52 sends a signal to the device 54, the device 54 comprising a processing unit/circuit and a converting unit/circuit. The processing circuit processes the received RF signal, which is transmitted in the form of data packets. The data packets are unpacked or processed by a processing circuit and converted from digital signals to analog signals by a conversion circuit. The analog signal may then be displayed on a monitor of the remote monitoring device.

The data unpacking device 54 is further shown in fig. 7 and as shown comprises a processing unit 56 and a conversion unit 58. When converted from digital to analog, the analog signals are displayed as graphical or alphanumeric data on each display 60. The unpacked signal can also serve as an audible alarm for each alarm indicator 62 provided on the remote monitoring device. A visual alarm indicator 64 may also be provided on the remote monitoring device to provide a visual alarm to the nurse or user if the measured physiological characteristic of the patient meets or exceeds an undesirable threshold. For printing out SpO of monitored patient₂Or a copy of other features, a printer 66 may also be provided on the remote monitoring device.

Fig. 8 illustrates an embodiment of the present invention in which bi-directional communication occurs between the finger oximeter and the remote monitoring device. In this case, the finger oximeter is equipped with an RF transceiver circuit 68, rather than an RF transmitter circuit, which enables the oximeter to transmit its oximeter signals to the RF transceiver circuit 70 of the remote monitoring device via a bidirectional RF link. The RF devices 68, 70 of the fig. 8 embodiment are adapted to operate in the bluetooth protocol to enable signals to be communicated bi-directionally between the finger oximeter and the remote monitoring device. As depicted in the system of fig. 6, the RF signals received from the RF transceiver 68 are unpacked and converted by the data unpacking and displaying device 72 so that the monitored oxygen saturation level of the patient is displayed on the remote monitoring device.

In addition to remotely monitoring the patient, the remote monitoring device of the system of FIG. 8 also has an activation circuit 74 that enables the user of the remote monitoring device to activate/deactivate the finger oximeter worn by the patient. It is desirable to be able to conserve the energy of the finger oximeter in the event that the patient must wear the finger oximeter for a longer period of time. Thus, a signal may be sent through the activation circuit 74 to activate the finger oximeter or deactivate it.

As described above, although the finger oximeter illustrated in FIGS. 1a-1d includes a display for the measured SpO to the patient₂And other physiological parameters, and a switch that allows the user to manually turn the device on, it should be understood that the display on the finger oximeter may be omitted and the patient's physiological parameters monitored remotely in a remotely located manner that does not require reading the finger oximeter. Thus, the switch for the finger oximeter shown in FIGS. 1a-1d may not be needed because the activation of the finger oximeter can be remotely controlled. Also, since the finger oximeter can be turned off remotely if it is not in use for a period of time, the problem of automatic turning off of the finger oximeter (e.g., removing the finger from the finger oximeter) is solved, thereby conserving the power of the battery pack of the finger oximeter.

Claims (27)

1. An oximeter, comprising:

a housing having an opening through which a finger of a patient may be placed;

a radiation emitter disposed within the housing, the radiation emitter outputting multi-frequency radiation to the finger;

a sensor disposed within the housing for monitoring radiation from the transmitter passing through the finger to obtain data relating to a physiological characteristic of the patient;

at least one circuit disposed within the housing for causing respective operation of the radiation emitter and the sensor, the circuit calculating at least a blood oxygen saturation level of the patient based on data obtained from the sensor; and

at least one other circuit disposed within the housing and cooperating with the one circuit to transmit an RF signal representative of the calculated oxygen saturation level to a remote device.

2. Oximeter of claim 1, wherein said another circuit comprises an RF transmitter circuit on a circuit board disposed within said housing for transmitting said signal to a remote RF receiver of said remote device via an RF link.

3. Oximeter of claim 1, wherein said housing comprises two halves, one of which is provided with at least one circuit board on which at least one of said one circuit and the other circuit unit is provided.

4. The oximeter of claim 1, further comprising:

a display for displaying a blood oxygen saturation level of the patient; and

the user may selectively activate the switch of the oximeter.

5. Oximeter of claim 2, wherein said RF transmitter circuit is capable of transmitting signals at selectable frequencies.

6. Oximeter of claim 1, wherein said RF signal is transmitted via bluetooth protocol.

7. The oximeter of claim 1, further comprising:

an energy source disposed within the housing, an

A power circuit for providing power from the power source to the radiation emitter, the sensor, and the first and second circuits, the power circuit being capable of being turned on or off by activation of a switch located within the housing or by a signal sent by the remote device.

8. The oximeter of claim 1, further comprising:

processor circuitry for controlling the respective operations of the radiation emitter, the sensor, and the first and second circuits, the operation of the processor circuitry being controllable by signals sent by the remote device.

9. A combination comprising a housing having an opening through which a patient's finger may be placed, a light emitter disposed within said housing, said light emitter emitting a multi-frequency light to the finger, a light sensor disposed within the housing for detecting light passing through said finger, a sensor disposed within the housing for converting the detected light to a signal representative of the patient's SpO₂A second circuit cooperating with the first circuit to send data packets to a remote device, the remote device not being on the housing with a display, the remote device having a receiver circuit tuned to receive data packets from the second circuit, the data packets being converted by a processing circuit of the remote device and being SpO for the patient₂Displaying on the remote device.

10. The combination of claim 9 wherein said second circuit comprises an RF transmitter circuit and wherein said receiver circuit comprises an RF receiver circuit, both said RF transmitter circuit and said receiver circuit being selected to operate at a given frequency.

11. The combination of claim 9, wherein said signal processing circuitry unpacks the data packets from said second circuitry, and said remote device includes circuitry for converting the data packets to be SpO₂The unpacked data packets are displayed on a display driver circuit of the remote device.

12. The combination of claim 9, wherein said housing includes SpO on which the patient can be displayed₂Thereby enabling display of the SpO of the patient on both the housing and the remote device₂。

13. The combination of claim 9 wherein said housing comprises two halves offset relative to each other, a circuit board having said first and second circuits disposed thereon, wherein the first and second circuits are disposed in one of said halves, and a switch disposed on said housing capable of manually activating said light emitter, light sensor, and said first and second circuits.

14. The combination of claim 9, further comprising:

a power circuit for providing power to the light emitter, the light sensor, and the first and second circuits, the power circuit being capable of being turned on or off by activation of a switch located in the housing or by a signal emitted by the remote device.

15. A system for remotely determining oxygen saturation in blood of a patient, comprising:

an oximeter, comprising:

a housing having an opening through which a finger of a patient may be placed;

a radiation emitter disposed within the housing, the radiation emitter transmitting multi-frequency radiation to a finger;

a sensor disposed within the housing for obtaining data from radiation passing through the finger;

processor circuitry disposed within the housing for operating the radiation emitter and the sensor and for calculating at least a blood oxygen saturation level of the patient based on data obtained from the sensor; and

a transmitter circuit disposed within the housing for transmitting the calculated oxygen saturation level from the housing via radio communication; and a remote monitoring device remote from the oximeter, the remote monitoring device having

A receiver circuit for receiving the calculated oxygen saturation level of blood from the oximeter; and

a display for displaying the received blood oxygen saturation.

16. The system of claim 15, wherein said oximeter's transmitter circuit comprises an RF transmitter circuit, the calculated oxygen saturation level of blood being transmitted by said RF transmitter circuit as an RF signal; and

wherein the receiver circuit comprises an RF receiver for receiving RF signals.

17. The system of claim 16, wherein the monitoring device includes signal processing circuitry for processing the RF signal and displaying the processed signal as a signal of the blood oxygen saturation level of the patient.

18. The system of claim 15, wherein the monitoring device comprises a multi-function medical monitor that displays EKG, pulse and blood pressure in addition to the blood oxygen saturation of the patient.

19. The system of claim 15 wherein said housing comprises two halves offset relative to each other, two circuit boards each having one of said processor and transmitter circuits disposed thereon, said processor and transmitter circuits being disposed on one of said halves, and a switch disposed on said housing capable of manually activating said light emitter, light sensor, and said processor and transmitter circuits.

20. The system of claim 15, further comprising:

a power circuit for providing power to the radiation emitter, the sensor, and the processor and emitter circuits, the power circuit being capable of being turned on or off by activation of a switch located on the housing or by a signal transmitted by the remote device.

21. An oximeter, comprising:

a housing having an opening through which a finger of a patient may be placed;

a radiation emitter disposed within the housing, the radiation emitter transmitting multi-frequency radiation to the finger;

a light sensor disposed within the housing for monitoring radiation passing through the finger to obtain data relating to the oxygen saturation level of the blood of the patient;

a processor disposed within the housing for calculating an oxygen saturation level of blood of the patient from the obtained data: and

a transmitter disposed within the housing for transmitting an RF signal to a remote device, the RF signal being indicative of blood oxygen saturation.

22. Oximeter of claim 21, wherein said housing comprises a display for displaying the calculated oxygen saturation level of blood of the patient.

23. Oximeter of claim 21, wherein said transmitter comprises an RF transmitter circuit for transmitting said signal to a remote RF receiver of the monitoring device via an RF link.

24. Oximeter of claim 21, wherein said housing comprises two halves, one of which is provided with at least one circuit board on which at least one of said one circuit and another circuit unit is provided, and a switch for selectively controlling power to said radiation emitter, light sensor, processor and emitter.

25. Oximeter of claim 21, wherein said transmitter circuit is capable of transmitting said RF signal at a selectable frequency.

26. Oximeter of claim 21, wherein said RF signal is transmitted via bluetooth protocol.

27. Oximeter of claim 21, wherein said processor circuit controls the respective operations of said radiation emitter, said sensor, and said emitter, said oximeter further comprising a power supply and power supply circuit for supplying power to said radiation emitter, said sensor, said emitter, and said processor circuit, the operation of said power supply circuit being selectively controllable by signals sent from said monitoring device.