Patent ID: 12186103

It should be clearly understood that the following description of these three embodiments is provided purely by way of illustration and that the scope of the invention is not limited to this description; rather the scope of the invention is set out in the attached claims.

FIG.5shows the detail of a module that is one embodiment of the invention and the module installed in a cellphone. There is a flexible bellows (1) sealed onto the end of the module case (9). The bellows (1) is filled with an inert transparent liquid. The bellows is transparent in the centre and, around the transparent region, is metallised to make electrical contact with a finger. The metallisation may use micropyramids or other rough structures to improve the electrical contact.

One or more photo-emitters (2) transmit light (shown by the dotted line) through the bellows (1). One or more photo-sensors (3) detect the light scattered back from a finger (15) pressed on the bellows (1).

A pressure sensor (4) measures the pressure in the liquid. A temperature sensor (5) detects the temperature of any object in its field of view, which is above the module.

The metallisation, photo-emitter(s), photo-sensor(s), pressure sensor and temperature sensor are all connected to a control and interfacing electronic unit (6). A cable (7) from this unit connects to the cellphone processor using the I2C interface standard. A second cable (8) connects this unit to a pad (12) on the cellphone used to make electrical contact to another finger.

The photo-emitter(s), photo-sensor(s), pressure sensor, temperature sensor and electronic unit may be separate silicon chips or some or all of them may be combined into a single chip.

The module is located at the top of the cellphone casing (12), above the screen (11). A pad (14) for connecting to a finger of the other hand is located at the bottom of the cellphone case. The user presses his/her index finger (15) against the bellows (1) to make a measurement. The temperature sensor is behind a window (16).

FIG.6shows the detail of a second module that is another embodiment of the invention and the module installed in a cellphone. There is an inextensible strap (21) attached to the module body (29). The surface of the strap is metallised to make electrical contact with a finger of a user.

One or more photo-emitters (22) transmits light (shown by the dotted line) beside the strap. One or more photo-sensors (23) detect the light scattered back from the finger.

There is a slot (24) in the body, below the point at which one end of the strap is attached. The beam formed by this slot deforms when force is applied to the strap and the deformation is measured by a strain gauge (25). A proximity sensor (31) measures the distance from the strap to the module body. A temperature sensor (26) detects the temperature of any object in its field of view, which is above the module.

The metallisation, photo-emitter(s), photo-sensor(s), strain gauge, proximity sensor and temperature sensor are all connected to a control and interfacing electronic unit (30). A cable (27) from this unit connects to the cellphone processor using the I2C or another interface standard. A second cable (28) connects this unit to a pad (34) on the cellphone used to make electrical contact to a finger on the user's other hand.

The photo-emitter(s), photo-sensor(s), proximity sensor, strain gauge temperature sensor and electronic unit may be separate silicon chips or some or all of them may be combined into a single chip.

The module is located at the top of the cellphone casing (32), above the screen (33). The pad (34) for connecting to a finger of the other hand is located at the bottom of the cellphone case. The user presses his index finger (35) against the strap to make a measurement. The temperature sensor is behind a window (36).

FIG.7shows the detail of a third module that is another embodiment of the invention and installation in the cellphone. There is an extensible strap (41) that is attaché at one end to the module body (49) and at the other end passes over a roller (45) to a spring (44). Within the spring (not shown) is a sensor to measure its length. The surface of the strap is metallised to make electrical contact with a finger.

One or more photo-emitters (42) transmit light (shown by the dotted line) beside the strap. One or more photo-sensors (43) detect the light scattered back from the finger.

A proximity sensor (51) measures the distance from the strap to the module body. A temperature sensor (46) detects the temperature of any object in its field of view, which is above the module.

The metallisation, photo-emitter(s), photo-sensor(s), spring length sensor, proximity sensor and temperature sensor are all connected to a control and interfacing electronic unit (50). A cable (47) from this unit connects to the cellphone processor using the I2C or another interface standard. A second cable (48) connects this unit to a pad (54) on the cellphone used to make electrical contact to a finger on the user's other hand.

The photo-emitter(s), photo-sensor(s), proximity sensor, spring length sensor, temperature sensor and electronic unit may be separate silicon chips or some or all of them may be combined into a single chip.

The module is located at the top of the cellphone casing (52), above the screen (53). The pad (54) for connecting to a finger of the other hand is located at the bottom of the cellphone casing. The user presses his/her index finger (55) against the strap to make a measurement. The temperature sensor is behind a window (56).

FIG.8shows the detail of a fourth module that is another embodiment of the invention and installation in the cellphone. There is a plate (61) into which a button (62) is inserted so that the top of the button (62) is flush with the plate. The button (62) rests on a force sensor (63). One or more photo-emitters (64) transmit light (shown by the dotted line) through the top of the button (62). One or more photo-sensors (65) detect the light scattered back from a finger pressed onto the button (62). The top of the button (62) is metallised (not shown).

The metallisation, photo-emitter(s), photo-sensor(s), and force sensor are all connected to a control and interfacing electronic unit (66). A cable (67) from this unit connects to the cellphone processor using the I2C or another interface standard. A second cable (68) connects this unit to a pad (73) on the cellphone used to make electrical contact to a finger on the user's other hand.

For calibration, the PHHCD may be oriented by the user to be pointing upwards or downwards and the orientation may be detected using the PHHCD's existing sensors. The change in signal of the force sensor under the weight of the button in these two orientations may be used to calibrate the force sensor.

A temperature sensor (69) may also be contained within the button (62) or located separately and connected to the button (62). The module is located at the bottom of the cellphone casing (71), below the screen (72). The pad (73) for connecting to a finger of the other hand is located at the top of the cellphone casing.

FIGS.9,10and11show three arrangements of optical sensors to be used in the PHHM of the present invention to measure the concentration of an analyte in blood. This may be incorporated into a PHHCD, or may be connected to a PHHCD, or may be constructed as a stand-alone device with its own user interface, power supply and other electronic and mechanical components. Not shown is the photoplethysmography means or the mechanism to modulate the intensity of the light beam. The three illustrations show discrete optical and other components; alternatively the sensor might be implemented as one or more integrated optical devices where several optical components are formed in a single block of transparent plastic.

InFIG.9, the light source (81) transmits a beam of light that passes through a filter (82) to select the spectral band of the light to be used. The spectral band is chosen to allow inexpensive components and materials to be used whilst maximising the sensitivity and discrimination with respect to the analyte. The beam is collimated by a lens (83) to shine through a body part such as finger (84). A beam splitter (85) divides the beam between a reference cell (86) and sample cell (87). Photosensors (88) measure the intensity of the beam after it has passed through each cell. A differential amplifier may be used to amplify the difference in signal between the two photosensors.

FIG.10shows another implementation in which a sample cell (96) containing gaseous analyte has one or more walls forming a diaphragm (109) moved by an actuator (99).

FIG.11shows another implementation in which the light source and detectors are on the same side of a body part, the detectors being sensitive to the light scattered back from the body part. A moving mirror (101) reflects light sequentially to each of two fixed mirrors (102) and hence to the reference cell or sample cell. One or more photosensors (108) measures the intensity of the beam that has passed the cells.

All of the illustrated embodiments of the PHHM include one or more electronic components (not shown) that can include: one or more pressure sensors, one or more analogue to digital convertors, one or more temperature sensors, a unique identifier and an interface to the electronic circuits of the cellphone.