WO2018208607A1

WO2018208607A1 - Improved photoplethysmographic sensor

Info

Publication number: WO2018208607A1
Application number: PCT/US2018/031150
Authority: WO
Inventors: Christopher T. Crowley; David R. Tobler
Original assignee: Somno Health Incorporated
Priority date: 2017-05-12
Filing date: 2018-05-04
Publication date: 2018-11-15
Also published as: WO2018208607A9

Abstract

An improved photoplethysmographic sensor includes a single-piece housing having a U-shaped configuration with opposing first and second portions, a light source supportably disposed on the first portion, a photodetector disposed on the second portion, and cable interconnected/interconnectable to the single-piece housing and including a preformed portion having an elastically deformable, undulating section. As improved method of manufacture of a photoplethysmographic sensor includes providing a single-piece housing that includes first and second portions and an intermediate portion adjoined therebetween, supportably disposing a light source and a photodetector on the first and second portions, respectively, and after the supportably disposing, shaping the intermediate portion to define a U-shaped configuration with the light source and photodetector disposed in opposing relation.

Description

IMPROVED PHOTOPLETHYSMOGRAPHIC SENSOR

RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional Patent Application No. 62/505,730 filed May 12, 2017, entitled "UNIQUE PULSE OXIMETRY SENSOR", which application is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to extracorporeal photoplethysmographic sensors utilized to measure pulse rate and/or blood oxygen content.

BACKGROUND OF THE INVENTION

Photoplethysmographic sensors include one or more light source(s) located to transmit light signal(s) into bodily tissue and a photodetector located to detect the light signal(s). In some arrangements, a single light source may utilized for purposes of pulse rate measurement. More commonly, pulse oximetry sensors include at least two light sources (e.g. light emitting diodes) having different center wavelengths (e.g. a red LED with a center wavelength of approximately 660 nm and an infrared LED with a center wavelength of approximately 940 nm). Absorption of light at red and infrared wavelengths differs significantly between blood high in oxygen and blood low in oxygen. Oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through.

Deoxygenated hemoglobin allows more infrared light to pass through and absorbs more red light. The LEDs are typically alternated in on/off signal transmissions thereby allowing the photodetector to output detection measurement signals in relation to each light signal. A ratio of the red light measurement to the infrared light measurement is typically determined by a processor and this ratio is then correlated to an Sp02 value by the processor.

As may be appreciated, the accuracy of photoplethysmographic measurements is dependent upon maintaining the positions of the sensor light source(s) and photodetector relative to the tissue and relative to each other. For such purposes, two basic sensor design approaches have been proposed. In one approach, the relatively inexpensive, easy to manufacture sensors are intended for one-time use and disposal, and typically comprise a flexible laminate arrangement that includes the light source(s) and photodetector. In the other approach, the relatively more expensive, difficult to manufacture sensors are intended for repeated use, and typically comprise complicated mechanical componentry with rigid and moving parts. While the two approaches have differing advantages/disadvantages, they have both suffered from a failure to recognize or adequately address the problem of how to manage the provision of multiple signal lines, or wires, for signal transmissions by the light source(s) and the photodetector, while avoiding entanglement and other issues associated with the provision of excess lengths of signal lines at or near the measurement site.

SUMMARY OF THE INVENTION

In one embodiment, an improved photoplethysmographic sensor is disclosed that includes a rigid, single-piece housing, or support member, having a U-shaped internal configuration and including opposing first and second portions that extend along opposite sides of a longitudinal axis of the U-shaped internal configuration and that define an open end thereof. The first and second portions are adjoined by a curved intermediate portion extending therebetween and defining a closed end of the U-shaped internal configuration. The sensor further includes at least one light source for transmitting a light signal and supportably disposed on a first side of the single-piece housing in the first portion thereof, and a photodetector for detecting said light signal and supportably disposed in opposing relation to the at least one light source on the first side of the single-piece housing in the second portion thereof.

In some implementations, the sensor may also include a cable interconnected or interconnectable to and extending away from the single-piece housing at the open end thereof, wherein the cable includes a preformed portion having an elastically deformable, undulating section. In turn, the sensor may include first and second sets of electrical signal transmission lines that extend through the cable and are separately interconnected to the light source(s) and the photodetector, respectively.

As will be further described, the provision of at least one light source and a photodetector supportably disposed on the same first side of a single-piece housing facilitates reduced cost manufacturing of the sensor, while also yielding the advantages of a durable, reusable sensor. Further, the provision of an interconnected or interconnectable cable having a preformed portion with an elastically deformable, undulating section facilitates the provision of signal lines extending therethrough so that the signal lines may be provided for interconnection to the light source(s) and detector in managed manner that advantageously avoids excess signal line entanglement and associated issues, while also accommodating movement of a tissue measurement site relative to the preformed portion of the cable.

In that regard, in some implementations the cable may be provided so that a center axis of the undulating section of the preformed portion extends substantially parallel to the longitudinal axis of the U-shaped internal configuration of the single-piece housing, thereby yielding an effective approach for the delivery of tensile forces to the undulating section by the single-piece housing (e.g. upon movement of the tissue measurement site). Further, and for analogous reasons, the preformed portion of the cable may further have a linear section interconnected to and extending between the single-piece housing and the undulating section, wherein a center axis of the linear section extends substantially parallel to the longitudinal axis of the U-shaped internal configuration.

In some arrangements, the undulating section of the preformed portion of the cable may have a zig-zag configuration, thereby reducing overall space requirements. Additionally, the undulating section may be of a substantially planar configuration to yield a low-profile arrangement in which the preformed portion of the cable may be secured to extend in substantially parallel relation to and away from a tissue measurement site.

In that regard, in some applications the sensor may further include a securement member, interconnected to the cable in spaced relation to the single-piece housing with the elastically deformable, undulating section therebetween, for securement of the cable in fixed relation to a tissue measurement site. By way of example, the securement member may comprise an elastomeric band, a complementary pair of hook and loop straps, a complementary pair of adjustable snap-connect straps, etc.

In some implementations, the first side of the single-piece housing may include opposing, inward-facing first and second recesses located in the first and second portions, respectively, wherein the light source(s) and photodetector are located in the first and second recesses, respectively. Further, first and second shield members may be located in bottom portions of the first and second recesses, respectively, underlying the light source(s) and the photodetector, respectively. The first and second shield members may be provided to block light passage therethrough and may include a reflective surface facing the light source(s) and the photodetector, respectively. In some arrangements, first and second protective window members may be located over the light source(s) and the photodetector, respectively, wherein the and second protective window members are light transmissive and provide a physical protection and electrical isolation layer.

In some embodiments, the first side of the single-piece housing may further include an inward-facing groove, extending continuously along the first and second portions and said intermediate portion, between the first and second recesses and continuing on to the open end. In turn, the first and second sets of electrical signal transmission lines, or corresponding signals lines interconnected thereto, may be located within the groove and separately interconnected to the light source(s) and the photodetector, respectively.

In some arrangements, the sensor may include a closure member interconnected to the first side of the single-piece housing in face-to-face relation over at least a majority of each of the first and second portions thereof, wherein the closure member captures the light sources and the photodetector, as well as the first and second sets of electrical transmission lines, the first and second shield members and first and second protective window members, between single- piece housing and the closure member. The closure member may include first and second openings disposed in alignment with the light source(s) and the photodetector, respectively, with the first and second protective window members located therebetween, respectively.

In contemplated embodiments, the first side of the single-piece housing may also include opposing, inward-facing concave channel regions in the first and second portions, respectively, that extend along the longitudinal axis of the U-shaped internal configuration on opposite sides thereof. As may be appreciated, the concave channel regions may be provided in finger/toe sensor applications to restrict relative movement between the single-piece housing measurement site.

In some embodiments, the single-piece housing may be advantageously formed in a single operation to define the various noted features in side-by-side relation on the first side thereof. For example, the first and second recesses, the first and second concave channel regions and the inward-facing groove may all be defined in side-by-side relation in a single operation, and in turn, the intermediate portion may be heat-shaped to a curved shape, thereby defining the U- shaped internal configuration.

In some implementations, a photoplethysmographic measurement device may be provided that includes a photoplethysmographic sensor having some or all of the noted features and further including a module interconnected or interconnectable to the cable and operable to transmit electrical light control signals to the light source(s) and to receive light detection signals from the photodetector via the signal transmission lines. In such embodiments, a securement member, may be interconnected to the module or the cable in spaced relation to the single-piece housing with the elastically deformable, undulating section therebetween, for securement of the cable in fixed relation to a securement location.

In another embodiment, a method to manufacture a photoplethysmographic sensor is disclosed. The method includes providing a single-piece housing that includes a first portion, an intermediate portion adjoining said first portion, and a second portion adjoining said intermediate portion, and supportably disposing and retaining at least one light source on a first side of said single-piece housing in the first portion thereof, and a photodetector on said first side of said single-piece housing in the second portion thereof. The method further includes shaping, after the supportably disposing and retaining, at least the intermediate portion of the single-piece housing to define a U-shaped internal configuration. More particularly, during the shaping, the intermediate portion is curved to define a closed end of the U-shaped internal configuration, and the first and second portions are disposed to extend in opposing relation along opposite sides of a longitudinal axis of the U-shaped internal configuration to define an open end and to locate the light source(s) and the photodetector in opposing relation.

In some implementations, the method may further include defining, after the supportably disposing and retaining, and prior to the shaping, a predetermined peripheral edge configuration of the single-piece housing. For example, the defining may include separating (e.g. via a die-cut operation) the single-piece housing from surrounding unused material. The predetermined peripheral edge configuration may be provided so that a width of the intermediate portion of the single-piece housing tapers down along opposing side edges in an inwardly arcuate shape from opposing ends of the intermediate section that are adjoined to the first and second portions of the single-piece housing. In that regard, the first and second portions may be of a common width and the opposing side edges of the intermediate portion may define an hour-glass configuration. In the later regard, the tapered-in width configuration of the intermediate portion may facilitate the shaping step, and in some implementation, may facilitate a limited degree of flexure to accommodate a limited degree of pivotable movement of the first and second portions at the open end after the shaping step (e.g. limited pivotable movement to increase the size of the open end during use).

In contemplated embodiments, the supportably disposing and retaining step may include interconnecting a closure member in face-to-face relation over at least a majority of each of said first and second portions on the first side of the single-piece housing, wherein the closure member captures the light source(s) and the photodetector between the closure member and the first side of the single-piece housing. In turn, the defining step may further include the defining of a predetermined edge configuration of the closure member that is coincidental with the predetermined peripheral edge configuration of the single-piece housing. For example, the defining may include separating (e.g. via a die-cut operation) the closure member from surrounding unused material.

In contemplated embodiments, the providing step may include forming the single-piece housing to define a predetermined surface configuration on the first side thereof. By way of example, such forming may comprise one of vacuum forming, pressure forming, heat forming, injection molding, reaction injection molding, and additive forming (e.g. via 3D printing). In conjunction with such forming, a plurality of single-piece housings may be formed from a single substrate, wherein after the forming, corresponding peripheral edge configurations of the plurality of single-piece housings may be defined via a separating step.

In some implementations, the forming may be completed so that the predetermined surface configuration includes first and second recesses on the first side of said single-piece housing in the first and second portions, respectively, wherein after the shaping the first and second recesses are disposed in opposing, inward-facing relation. In turn, the supportably disposing and retaining step may include locating the light source(s) and the photodetector in the first and second recesses, respectively.

Similarly, in some implementations the forming may be completed so that the predetermined surface configuration includes concave, first and second channel regions on the first side of the single-piece housing in the first and second portions thereof, respectively, and wherein after the shaping said first and second channel regions are disposed in opposing, inward-facing relation. The first and second channel regions may each include opposing sidewalls that extend along the first and second portions, respectively.

Further, in some implementations the forming may be completed so that the predetermined surface configuration includes a groove on the first side of said single-piece housing that extends continuously along the first portion, the second portions and the intermediate portion thereof, between said first and second recesses to said open end, wherein after said shaping groove is inward-facing. In turn, the supportably disposing and retaining may further include locating first and second sets of electrical signal transmission lines in the groove, wherein the first and second sets of electrical signal transmission lines are provided for separate electrical interconnection to the light source(s) and the photodetector, respectively.

In some arrangements, the supportably disposing may include locating first and second shield members in bottom portions of said first and second recesses prior to the locating of the light source(s) and the photodetector therein, respectively. The first and second shield members may be provided to block light passage therethrough and may include a reflective surface facing the light source(s) and the photodetector, respectively. Similarly, the supportably disposing may include locating first and second protective window members over the light source(s) and the photodetector, respectively, wherein said first and second protective window members are light transmissive and provide a physical protection and electrical isolation layer.

In some embodiments the supportably disposing may further include interconnecting a closure member in face-to-face relation over at least a majority of each of said first and second portions on the first side of the single-piece housing, wherein the closure member captures the light source(s) and the photodetector between the closure member and the first side of the single-piece housing. The closure member may be flexible so that, during and after said shaping, the closure member assumes a U-shaped configuration coincidental to the U-shaped internal configuration of the single-piece housing. The closure member may include first and second openings disposed in alignment with the light source(s) and the photodetector, respectively.

In some implementations, the method may further include defining together, after the supportably disposing and retaining, and prior to the shaping, both a predetermined peripheral edge configuration of the single-piece housing and a predetermined edge configuration of the closure member that is coincidental with the predetermined peripheral edge configuration of the single-piece housing. For example, such defining may include separating both the single- piece housing from surrounding unused material, and the closure member from surrounding unused material, in a single operation (e.g. a single die-cut operation).

In some implementations, the method may further include interconnecting a first end of a cable to the single-piece housing, wherein the cable includes a preformed portion having an elastically deformable, undulating section. In turn, the sensor may include first and second sets of electrical signal transmission lines that extend through the cable and are separately interconnected to the light source(s) and the photodetector, respectively. The preformed portion of the cable may include a substantially linear section interconnected to the undulating section.

In some embodiments a method for manufacture of a photoplethysmographic measurement device is also disclosed, which includes the method for manufacture of a photoplethysmographic sensor as disclosed herein, and further comprises interconnecting a module to a second end of the cable after the shaping step, wherein the module is operable to transmit electrical light control signals to the light source(s) via said cable, and to receive light detection signals from said photodetector via said cable.

Numerous additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the embodiment descriptions provided hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 illustrates one embodiment of a photoplethysmographic sensor. Fig. 2 illustrates the photoplethysmographic sensor embodiment of Fig. 1 located at measurement site during use.

Fig. 3 illustrates an assembly view of the photoplethysmographic sensor embodiment of Fig. 1 prior to a shaping operation.

Fig. 4 illustrates an assembly view of the photoplethysmographic sensor embodiment of

Fig. 1 in a final configuration.

Fig. 5A illustrates a perspective view of the photoplethysmographic sensor embodiment of Fig. 1 after assembly.

Fig. 5B illustrates a perspective view of the photoplethysmographic sensor embodiment of Fig. 1 after assembly and a peripheral configuration defining operation.

Fig. 6 illustrates an embodiment of a method of manufacture of a photoplethysmographic sensor embodiment.

DETAILED DESCRIPTION

The following description is not intended to limit the invention to the forms disclosed herein. Consequently, variations and modifications commensurate with the following teachings, skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention.

Fig. 1 illustrates an embodiment of a photoplethysmographic sensor 1, as included in a photoplethysmographic measurement device 100. The photoplethysmographic sensor 1 includes a single-piece housing 10 and a cable 20 that is interconnected to and extends away from an open end of the single-piece housing 10. As will be further described, one or more light source(s) and a photodetector may be supportably disposed on the single-piece housing 10, and the single-piece housing 10 may be selectively connected to/disconnected from a measurement site.

The cable 20 is preformed to assume a predetermined configuration. As shown, the cable 20 may include an elastically deformable, "spring-loaded" undulating section 22, and a linear section 24 adjoined thereto. In the illustrated embodiment, the linear section 24 is located between the single-piece housing 10 and the undulating section 22. The elastic deformability of the undulating section 22 allows the cable 20 to extend from/return to the predetermined configuration in response to a tensile force applied by the single-piece housing 10 during use of sensor 1. In turn, electrical signal transmission lines that extend through the cable 20 to/from the referenced light source(s) and photodetector may be effectively managed in a manner that reduces or avoids entanglement and related issues.

The preformed, undulating section 22 and preformed, linear section 24 may have corresponding center axes, and in the illustrated embodiment, such center axes are aligned and extend parallel to a longitudinal axis AA that extends along the single-piece housing 10, thereby facilitating a predictable translation of tensile forces from the single-piece housing to the linear section 24 and undulating section 22. In the illustrated embodiment, the undulating section 22 is of a zig-zag configuration, and alternative configurations may be employed. The preformed cable 20 may have a flat profile along the length thereof, thereby facilitating non- obtrusive positioning of the sensor 1 during use.

With further reference to Fig. 1, sensor 1 may include a securement member 30 interconnected to the cable 20 at a location spaced from the single-piece housing 10, with the undulating section 22 and linear section 24 disposed therebetween, wherein the securement member 30 may be secured to a securement location spaced from a measurement site at which the single-piece housing 10 is located. The securement member 30 may comprise an elastic band, a pair of interconnectable/disconnectable straps (e.g. straps having complimentary hook and loop fasters), a pair of straps have complimentary snap fit connectors, etc. While the securement member 30 may be connected directly to the preformed cable 20, with an additional length of cable extending therebeyond (shown in phantom lines), in the illustrated embodiment the securement member 30 is shown interconnected to a module 110 that is interconnected to an end of the cable 20. The module 1 10 may be provided as part of the plethysmographic measurement device 100, and may be operable to transmit light control signals to and receive light detection signals from the light source(s) and photodetector, respectively, supportable disposed on the single-piece housing 10.

Reference is now made to Fig. 2 which illustrates photoplethysmographic sensor 1 located at a finger-tip measurement site, with securement member 30 secured to a wrist securement location. In turn, the linear section 24 of preformed cable 20 is disposed to extend away from the single-piece housing 10 along a corresponding finger length and adjoin the undulating section along a back-side of a corresponding hand (e.g. opposite to the palm-side of the hand). As may appreciated, the provision of the elastically deformable, undulating section 22 automatically extends from/returns to the predetermined configuration shown so as to accommodate common hand movements during use (e.g. movements between an open hand and clenched fist). Optionally, the photoplethysmographic sensor 1 may be interconnected to/disconnected from the measurement site via a length of adhesive tape or via other interconnection/disconnection members.

Figs. 3 and Fig. 4 illustrate exploded views of the componentry of photoplethysmographic sensor 1, as configured during manufacture of sensor 1 and as configured after manufacture of sensor 1, respectively, in accordance with some embodiments. In that regard, Fig. 3 shows single-piece housing 10 having first and second portions 40, 42, and an intermediate portion 44 adjoined to and extending between the first and second portions 40, 42, wherein such portions of the single-piece housing 1 extend from one end to the other in a generally planar configuration to accommodate stacked assembly of additional componentry. In turn, Fig. 4 shows single-piece housing 10 having a U-shaped intemal configuration, with intermediate portion 44 having been shaped to a curved configuration at a closed end of the U- shaped configuration, and first and second portions 40, 42 extending along opposite sides of a longitudinal axis AA of the U-shaped configuration to define an open end thereof. In that regard, in contemplated embodiments, the components of sensor 1 may be assembled and interconnected in a laminate manner, and thereafter the single-piece housing 1 may be shaped to provide the U-shaped intemal configuration together with the other components of the assembly.

In that regard, and with further reference to Figs. 3 and 4, sensor 1 may further comprise at least one light source 50 (e.g. one or more LED's) and a photodetector 52 (e.g. an array of light sensitive regions) interconnected to corresponding first and second sets of signal transmission lines 60a, 60b, respectively, and a closure member 70 having first and second openings 72a, 72b, overlying the light source(s) 50, the photodetector 52, and the first and second sets of signal transmission lines 60a, 60b, which components may be supportably disposed on the single-piece housing 10. Further, sensor 1 may include first and second shield members 54a, 54b underlying the light sources(s) 50 and photodetector 52, respectively, wherein the first and second shield members 54a, 54b, block light passage therethrough and include a reflective surface facing the light source(s)50 and photodetector 52, respectively. Additionally, sensor 1 may include first and second protective window members 56a, 56b located over the light source(s) 50 and photodetector 52, respectively, wherein the first and second protective windows are light transmissive and provide a physical protection and electrical isolation layer.

As shown in Figs. 3 and 4, the single-piece housing 10 may be provided to include a predetermined surface configuration on a first side 12 (best shown in Fig. 4), elements of which predetermined surface configuration are also evident on a second side 14 (best shown in Fig. 3). In the later regard, in Fig. 3 the components of sensor 1 are shown in a downward-facing, laminate orientation. In contemplated manufacturing embodiments, the components of sensor 1 are stacked in an opposite, upward-facing, laminate orientation, wherein the light source(s) 50, photodetector 52, underlying first and second shield members 54a, 54b, respectively, and interconnected first and second signal line sets 60a, 60b, respectively, are supportably disposed on the first side 12 of single-piece housing 10, then first and second protective window members 56a, 56b are supportably disposed over light source(s) 50 and photodetector 52, respectively, then closure member 70 is disposed over the foregoing components, with openings 72a, 72b aligned with light source(s) 50 and photodetector 52, respectively, and supportably interconnected to the first side 12 of single-piece housing 10.

As illustrated in Figs. 3 and 4, the predetermined surface configuration of single-piece housing 10 may include first and second recesses 80a, 80b located in first and second portions 40, 42, respectively, for supportably receiving the first and second shield members 54a, 54b, and light source(s) 50 and photodetector 52 therein, respectively. Further, the predetermined surface configuration of single-piece housing may include a groove 82 extending along first portion 40 from an end thereof (e.g. at the open end of U-shaped configuration), and along intermediate portion 44 and second portion 42 from first recess 80a to second recess 80b, for supportably receiving and routing the first and second signal line sets 60a, 60b therein. In addition, the predetermined surface configuration of single-piece housing may include first and second concave channel regions 84a, 84b that extend along and within first and second portions 40 42, respectively. As shown in Fig. 4, after the single-piece housing 10 is shaped to the U- shaped configuration, the first and second concave channel regions 84a, 84b are disposed in opposing, inward-facing relation on opposite sides of longitudinal axis AA, e.g. for retainably receiving a measurement site therebetween (e.g. a finger/toe) during use of the sensor 1.

As shown, an end of the cable 20 may also be received in groove 82 and interconnected therein to single-piece housing 10. In other arrangements, the first and second signal line sets 60a, 60a may be provided with a first end connector at the open end of groove 82, and the cable 20 may be provided with separate first and second signal line sets extending therethrough and a second end connector interconnected to the separate first and second signal line sets, wherein the first end connector and second end connector may be selectively interconnectable (e.g. to establish electrical connections between corresponding ones of the first and second signal line sets 60a, 60b, and separate first and second signal line sets extending through cable 20) and disconnectable (e.g. to facilitate replacement of the cable 20 and/or the single-piece housing 10 and components interconnected thereto). In contemplated embodiments, the single-piece housing 10 may comprise a polymer- based material (e.g. a thermoplastic material) that may be formed via a number of different types of forming processes, including forming to provide the described predetermined surface configuration having first and second recesses 80a, 80b, groove 82, and concave channel regions 84a, 84b. Further, various ones of the additional above-referenced components of the sensor 1 may comprise an adhesive back surface to facilitate interconnected assembly of such components. In particular, the first and second protective window members 56a, 56b may be provided with adhesive back surfaces and sized to extend beyond first and second recesses 80a, 80b for interconnection to the single-piece housing 10, and closure member 70 may be provided with an adhesive back surface and sized to extend over at least a maj ority of the first and second portions 40, 42 on the first side 12 of the single-piece housing 10, and preferably over the entirety of the first side 12 of the single-piece housing 10, for interconnection therewith. In some embodiments, the closure member 70 may comprise a foam material to provide a degree of cushioning and conformability.

In some embodiments, after assembly of the components of sensor 1, as shown in Fig.

5A and described above, a predetermined peripheral edge configuration of the single-piece housing 10 may be defined, and a coincidental predetermined edge configuration of closure member 70 may be defined, as shown in Fig. 5B. For example, the single-piece housing 10 shown in Fig. 5 may be separated (e.g. via a die-cut operation) from unused, surrounding material of the single-piece housing shown in Fig. 3 to define the predetermined peripheral edge configuration, and a closure member 70 having a predetermined edge configuration coincidental to that shown in Fig. 5 may be separated from unused, surrounding material of the closure member shown in Fig. 3.

As shown in Fig. 5B, the predetermined peripheral edge configuration of single-piece housing 10 may be provided so that a width of the intermediate portion 44 tapers down along opposing side edges in an inwardly arcuate shape from opposing ends of the intermediate portion 44 that are adjoined to the first and second portions 40, 42. In that regard, the first and second portions 40, 42 may be of a common width and the opposing side edges of the intermediate portion 44 may define an hour-glass configuration. In the later regard, the tapered- in width configuration of the intermediate portion 44 may facilitate subsequent heat-shaping to define the sensor 1 configuration shown in Fig. 4, and in some implementation, may facilitate a limited degree of flexure to accommodate a limited degree of pivotable movement of the first and second portions 40, 42 at the open end after the shaping (e.g. limited pivotable movement to increase the size of the open end during use). Reference is now made to Fig. 6 which illustrates one embodiment of a method of manufacture of a photoplethysmographic sensor (e.g. sensor 1). As shown, the method may include providing a single-piece housing 200, wherein the single-piece housing (e.g. single- piece housing 10) may include a first portion, an intermediate portion adjoining the first portion, and a second portion adjoining the intermediate portion. The method may further include supportably disposing and retaining at least one light source (e.g. light source(s) 50) and a photodetector (e.g. photodetector 52) on the first side of the single-piece housing 210. The method may further include shaping the single-piece housing to define a U-shaped internal configuration 230. In some implementations, the method may further include defining a predetermined peripheral edge configuration of the single-piece housing 220.

In contemplated embodiments, the providing step 200 may include forming the single-piece housing to define a predetermined surface configuration on the first side thereof 202. By way of example, such forming may comprise one of vacuum forming, pressure forming, heat forming, injection molding, reaction injection molding, and additive forming (e.g. via 3D printing). In conjunction with such forming, a plurality of single-piece housings may be formed from a single substrate, wherein after the forming, corresponding peripheral edge configurations of the plurality of single-piece housings may be defined via a separating step.

In some implementations, the forming 202 may be completed so that the predetermined surface configuration includes first and second recesses on the first side of said single-piece housing, wherein after the shaping 230 the first and second recesses are disposed in opposing, inward-facing relation. In turn, the supportably disposing and retaining step 210 may include locating the light source(s) and the photodetector in the first and second recesses, respectively.

Similarly, in some implementations the forming step 202 may be completed so that the predetermined surface configuration includes concave, first and second channel regions on the first side of the single-piece housing, wherein after the shaping step 230 the first and second channel regions are disposed in opposing, inward-facing relation. The first and second channel regions may each include opposing sidewalls that extend along the first and second portions, respectively.

Further, in some implementations the forming step 202 may be completed so that the predetermined surface configuration includes a groove on the first side of said single-piece housing, wherein after the shaping step 230 the groove is inward-facing. In turn, the supportably disposing and retaining step 210 may further include locating first and second sets of electrical signal transmission lines (e.g. signal line sets 60a, 60b) in the groove, wherein the first and second sets of electrical signal transmission lines are provided for separate electrical interconnection to the light source(s) and the photodetector, respectively.

In contemplated embodiments, the supportably disposing and retaining step may include interconnecting a closure member( closure member 70) in face-to-face relation over the first side of the single-piece housing 212, wherein the closure member captures the light source(s) and the photodetector between the closure member and the first side of the single-piece housing. In turn, the defining step 220 may further include the defining of a predetermined edge configuration of the closure member that is coincidental with the predetermined peripheral edge configuration of the single-piece housing.

In some arrangements, the supportably disposing and retaining step 210 may further include locating first and second shield members in bottom portions of said first and second recesses prior to the locating of the light source(s) and the photodetector therein, respectively. The first and second shield members may be provided to block light passage therethrough and may include a reflective surface facing the light source(s) and the photodetector, respectively. Similarly, the supportably disposing and retaining step 210 may include locating first and second protective window members over the light source(s) and the photodetector, respectively, wherein said first and second protective window members are light transmissive and provide a physical protection and electrical isolation layer.

The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain known modes of practicing the invention and to enable others skilled in the art to utilize the invention in such or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.

Claims

CLAIMS What is claimed is:

1. A photoplethysmographic sensor, comprising:

a single-piece housing having a U-shaped internal configuration and including opposing first and second portions that extend along opposite sides of a longitudinal axis of the U-shaped internal configuration and that define an open end thereof, wherein the first and second portions are adjoined by a curved intermediate portion extending therebetween and defining a closed end of the U-shaped internal configuration;

at least one light source for transmitting a light signal and supportably disposed on said first portion of said single-piece housing;

a photodetector for detecting said light signal and supportably disposed in opposing relation to the at least one light source on said second portion of said single-piece housing; and, a cable interconnected or interconnectable to and extending away from the single-piece housing at the open end thereof, wherein the cable includes a preformed portion having an elastically deformable, undulating section.

2. A photoplethysmographic sensor as recited in Claim 1 , wherein a center axis of said undulating section of the preformed portion of said cable extends substantially parallel to the longitudinal axis of the U-shaped internal configuration.

3. A photoplethysmographic sensor as recited in Claim 1 , said preformed portion of said cable further having a linear section interconnected to and extending between said single-piece housing and said undulating section, wherein a center axis of said linear section extends substantially parallel to the longitudinal axis of the U-shaped internal configuration.

4. A photoplethysmographic sensor as recited in Claiml , wherein said undulating section is of a zig-zag configuration.

5. A photoplethysmographic sensor as recited in Claim 1, wherein said undulating section is of substantially planar configuration.

6. A photoplethysmographic sensor as recited in Claim 1, further comprising: a securement member, interconnected to said cable in spaced relation to said support member with said elastically deformable, undulating section therebetween, for securement of said cable in fixed relation to a support location.

7. A photoplethysmographic sensor as recited in Claim 1, wherein said first and second portions of said single-piece housing include opposing, inward-facing first and second recesses, respectively, and wherein said at least one light source and said photodetector are located in said first and second recesses, respectively.

8. A photoplethysmographic sensor as recited in Claim 7, further comprising:

first and second shield members located in bottom portions of said first and second recesses, respectively, and underlying said at least one light source and said photodetector, respectively, wherein said first and second shield members each block light passage therethrough and include a reflective surface facing said at least one light source and said photodetector, respectively.

9. A photoplethysmographic sensor as recited in Claim 7, further comprising:

first and second protective window members located over said at least one light source and said photodetector, respectively, wherein said first and second protective window members are light transmissive and provide a physical and electrical protection layer.

10. A photoplethysmographic sensor as recited in Claim 7, wherein said single piece housing includes an inward-facing groove, extending continuously along said first and second portions and said intermediate portion, between the first and second recesses and to said open end, and further comprising:

first and second sets of electrical signal transmission lines located within said groove and separately interconnected to said at least one light source and said photodetector, respectively.

11. A photoplethysmographic sensor as recited in Claim 10, further comprising:

a closure member interconnected in face-to-face relation over at least a majority of each of said first and second portions, wherein said closure member captures said at least one light source, said photodetector, and said first and second sets of electrical transmission lines the between single-piece housing and said closure member, and wherein said closure member includes first and second openings disposed in alignment with said at least one light source and said photodetector, respectively.

12. A photoplethysmographic sensor as recited in Claim 10, wherein said first and second portions of said single-piece housing include opposing, inward-facing concave channel regions that extend along said longitudinal axis of the U-shaped internal configuration on opposite sides thereof.

13. A photoplethysmographic sensor as recited in Claim 12, wherein said single-piece housing is formed in a single operation to define said first and second recesses, said channel regions and said inward-facing groove, then heat shaped to define said U-shaped internal configuration.

14. A photoplethysmographic measurement device including a photoplethysmographic sensor as recited in Claim 1 , and further comprising:

a module interconnected or interconnectable to said cable and operable to transmit electrical light control signals to said at least one light source via said cable, and to receive light detection signals from said photodetector via said cable.

15. A photoplethysmographic measurement device as recited in Claim 14, and further comprising:

a securement member, interconnected to said module or said cable in spaced relation to said single-piece housing with said elastically deformable, undulating section therebetween, for securement of said cable in fixed relation to a support location.

16. A method to manufacture a photoplethysmographic sensor, comprising:

providing a single-piece housing that includes a first portion, an intermediate portion adjoining said first portion, and a second portion adjoining said intermediate portion;

supportably disposing and retaining at least one light source on a first side of said single-piece housing in said first portion thereof, and a photodetector on said first side of said single-piece housing in said second portion thereof;

shaping, after said supportably disposing and retaining, at least said intermediate portion of said single-piece housing to define a U-shaped internal configuration, wherein during said forming: said first and second portions are disposed to extend in opposing relation along opposite sides of a longitudinal axis of the U-shaped internal configuration and to define an open end, and wherein said at least one light source and said photodetector are disposed in opposing relation; and,

said intermediate portion is curved to define a closed end of said U-shaped internal configuration.

17. A method as recited in Claim 16, further comprising:

defining, after said supportably disposing and retaining, and prior to said shaping, a predetermined peripheral edge configuration of said single-piece housing.

18. A method as recited in Claim 17, wherein said supportably disposing and retaining further comprises:

interconnecting a closure member in face-to-face relation over at least a majority of each of said first and second portions on said first side of the single-piece housing, wherein said closure member captures said at least one light source and said photodetector between the closure member and the first side of the single-piece housing.

19. A method as recited in Claim 18, wherein said defining includes defining a predetermined edge configuration of said closure member that is coincidental with the predetermined peripheral edge configuration of the single-piece housing.

20. A method as recited in Claim 16, wherein said providing comprises:

forming said single-piece housing to define a predetermined surface configuration on said first side of the single-piece housing.

21. A method as recited in Claim 20, wherein said forming comprises one of vacuum forming, pressure forming, heat forming, injection molding, reaction injection molding, and additive forming.

22. A method as recited in Claim 20, wherein:

said predetermined surface configuration includes first and second recesses on said first side of said single-piece housing in said first and second portions, respectively, wherein after said shaping said first and second recesses are disposed in opposing, inward-facing relation ; and,

said supportably disposing and retaining includes locating said at least one light source and said photodetector in said first and second recesses, respectively.

23. A method as recited in Claim 22, wherein said predetermined surface configuration further includes concave, first and second channel regions on said first side of said single-piece housing in said first and second portions thereof, respectively, and wherein after said shaping said first and second channel regions are disposed in opposing, inward-facing relation.

24. A method as recited in Claim 22, wherein:

said predetermined surface configuration further includes a groove on said first side of said single-piece housing that extends continuously along in said first and second portions and said intermediate portion thereof, between said first and second recesses to said open end, wherein after said second forming said groove is inward-facing; and,

said supportably disposing and retaining further includes locating first and second sets of electrical signal transmission lines in said groove, wherein said first and second sets of electrical signal transmission lines are provided for separate electrical interconnection to said at least one light source and said photodetector, respectively.

25. A method as recited in Claim 22, wherein said supportably disposing further includes: locating first and second shield members in bottom portions of said first and second recesses prior to said locating of said at least one light source and said photodetector therein, respectively, wherein said first and second shield members each block light passage therethrough and include a reflective surface facing said at least one light source and said photodetector, respectively; and,

locating first and second protective window members over said at least one light source and said photodetector, respectively, wherein said first and second protective window members are light transmissive and provide a physical protection layer.

26. A method as recited in Claim 22, wherein said supportably disposing further includes: interconnecting a closure member in face-to-face relation over at least a majority of each of said first and second portions on said first side of the single-piece housing, wherein said closure member captures said at least one light source and said photodetector between the closure member and the first side of the single-piece housing, wherein said closure member includes first and second openings disposed in alignment with said at least one light source and said photodetector, respectively, and wherein during and after said shaping said cushion member assumes a U-shaped configuration coincidental to the U-shaped internal configuration of the single-piece housing.

27. A method as recited in Claim 26, further comprising:

defining together, after said supportably disposing and retaining, and prior to said shaping, both a predetermined peripheral edge configuration of said single-piece housing and a predetermined edge configuration of said closure member that is coincidental with the predetermined peripheral edge configuration of the single-piece housing.

28. A method as recited in Claim 16, further comprising:

interconnecting a first end of a cable to said single-piece housing, wherein the cable includes a preformed portion having an elastically deformable, undulating section.

29. A method as recited in Claim 28, said preformed portion of said cable further having a substantially linear section interconnected to said undulating section.

30. A method for manufacture of a photoplethysmographic measurement device, including the method recited in Claim 28, further comprising;

interconnecting a module to a second end of said cable after said shaping, wherein said module is operable to transmit electrical light control signals to said at least one light source via said cable, and to receive light detection signals from said photodetector via said cable.

31. A photoplethysmographic sensor, comprising:

a support member;

at least one light source for transmitting a light signal and supportably interconnected to said support member;

a photodetector for detecting said light signal and supportably interconnected to said support member; and,

a cable interconnected or interconnectable to and extending away from said support member, wherein the cable includes a preformed portion having an elastically deformable, undulating section; and, a securement member, interconnected to said cable in spaced relation to said support member with said elastically deformable, undulating section therebetween, for securement of said cable in fixed relation to a support location.

32. A photoplethysmographic sensor as recited in Claim 31, wherein said undulating section is of a zig-zag configuration.

33. A photoplethysmographic sensor as recited in Claim 31, wherein said undulating section is of substantially planar configuration.

34. A photoplethysmographic sensor as recited in Claim 31, wherein said support member has a U-shaped internal configuration and includes opposing first and second portions that extend along opposite sides of a longitudinal axis of the U-shaped internal configuration and that define an open end thereof, wherein the first and second portions are adjoined by a curved intermediate portion extending therebetween and defining a closed end of the U-shaped internal configuration, wherein said at least one light source is and supportably disposed on said first portion of said support member, and wherein said photodetector is supportably disposed in opposing relation to the at least one light source on said second portion of said support member.

35. A photoplethysmographic sensor as recited in Claim 34, wherein a center axis of said undulating section of the preformed portion of said cable extends substantially parallel to the longitudinal axis of the U-shaped internal configuration.

36. A photoplethysmographic sensor as recited in Claim 34, said preformed portion of said cable further having a linear section interconnected to and extending between said support member and said undulating section, wherein a center axis of said linear section extends substantially parallel to the longitudinal axis of the U-shaped internal configuration.

37. A photoplethysmographic sensor as recited in Claim 34, wherein said support member is defined by a single-piece housing.

38. A photoplethysmographic sensor as recited in Claim 34, wherein said first and second portions include opposing, inward-facing first and second recesses, respectively, and wherein said at least one light source and said photodetector are located in said first and second recesses, respectively.

39. A photoplethysmographic sensor as recited in Claim 38, further comprising:

40. A photoplethysmographic sensor as recited in Claim 38, further comprising:

first and second protective window members located over said at least one light source and said photodetector, respectively, wherein said first and second protective window members are light transmissive and provide a physical protection and electrical protection layer.

41. A photoplethysmographic sensor as recited in Claim 38, wherein said single piece housing includes an inward-facing groove, extending continuously along said first and second portions and said intermediate portion, between the first and second recesses and to said open end, and further comprising:

42. A photoplethysmographic sensor as recited in Claim 41, further comprising:

a closure member interconnected in face-to-face relation over at least a majority of each of said first and second portions, wherein said closure member captures said at least one light source, said photodetector, and said first and second sets of electrical transmission lines the between the support member and said closure member, and wherein said closure member includes first and second openings disposed in alignment with said at least one light source and said photodetector, respectively.

43. A photoplethysmographic sensor as recited in Claim 41, wherein said first and second portions of said single-piece housing include opposing, inward-facing concave channel regions that extend along said longitudinal axis of the U-shaped internal configuration on opposite sides thereof.

44. A photoplethysmographic sensor as recited in Claim 43, wherein said single-piece housing is formed in a single operation to define said first and second recesses, said channel regions and said inward-facing groove, then heat shaped to define said U-shaped internal configuration.

45. A photoplethysmographic measurement device including a photoplethysmographic sensor as recited in Claim 31, and further comprising:

a module, interconnected or interconnectable to said cable at said securement member, and operable to transmit electrical light control signals to said at least one light source via said cable, and to receive light detection signals from said photodetector via said cable.