Multimodal sensing patch with active contact pressure control and quantification for physiological measurements and biomarker detection

Abstract

A wearable biosensing system includes a case, a contact carriage, a biosensor, and a contact pressure management unit. The case is adapted to be fixed to a skin surface of a user. The contact carriage is mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user. The biosensor is configured to measure physiological signals of the user. The contact pressure management includes at least one pressure sensor configured to output pressure data.

Description

MULTIMODAL SENSING PATCH WITH ACTIVE CONTACT PRESSURE CONTROL AND QUANTIFICATION FOR PHYSIOLOGICAL MEASUREMENTS AND BIOMARKER DETECTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This nonprovisional application claims the benefit and priority, under 35 U.S.C. § 119(e) and any other applicable laws or statutes, to U.S. Provisional Patent Application No. 63 / 588,556 filed on October 6, 2023, the entire disclosure of which is hereby expressly incorporated herein by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under Award Number 1648451 provided by NSF. The government has certain rights in the invention.FIELD OF THE DISCLOSURE

[0003] The present disclosure relates generally to biosensing systems, and more specifically, to biosensing systems with skin-contacting sensors for detecting physiological information.BACKGROUND

[0004] Biosensors are becoming an important tool for modern healthcare. Whether in a clinic, a hospital, or at home, biosensors may be utilized to provide accurate and important health care information.

[0005] However, a number of undesirable noise and discrepancy sources can interfere with signal analysis from biosensors that function via contact with a user’s skin surface. In particular, variable pressures that the biosensor applies onto the skin surface can degrade signals from biosensors and contact pressure variability can mask biomarkers contained within a signal. The present disclosure provides systems and methods that overcome these limitations.SUMMARY

[0006] The present disclosure may comprise one or more of the following features and combinations thereof.

[0007] According to an aspect of the present disclosure, a wearable biosensing system includes a case, a contact carriage, a biosensor, and a contact pressure management unit. The case is adapted to be fixed to a skin surface of a user. The contact carriage is mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user. The biosensor is mounted to the contact carriage for movement therewith relative to the case and configured to measure physiological signals of the user.

[0008] In some embodiments, the contact pressure management unit includes a carriage driver and at least one pressure sensor mounted for movement with the contact carriage. The carriage driver is configured to move the contact carriage, the biosensor, and the at least one pressure sensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user. The at least one pressure sensor is configured to output pressure data suitable for determining the contact pressure developed between the contact carriage and the skin surface of the user. The determined contact pressure can be used as an input for adjusting the position of the contact carriage via the carriage driver.

[0009] These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Fig. 1 is a perspective view of a wearable biosensing system fixed to a skin surface of a user, the system including a biosensor configured to measure physiological signals of the user and a controller in communication with the biosensor to receive physiological signal data therefrom;

[0011] Fig. 2 is an enlarged view of the wearable biosensing system of Fig. 1 , the wearable biosensing system further including a case, a contact carriage within the case and mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, and a contact pressure management unit configured to change the contact pressure applied to the skin surface of the user by the contact carriage;

[0012] Fig. 3 is a block diagram of the system of Fig. 2 showing that the biosensor is mounted to the contact carriage for movement therewith and the contact pressure management unit includes at least one pressure sensor also mounted to the contact carriage for movement therewith relative to the case, and further showing that the contact pressure management unit includes a carriage driver coupled with the case and the contact carriage to move the contact carriage, the biosensor, and the at least one pressure sensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user;

[0013] Fig. 4 is an exploded assembly top view of the system of Fig. 2 showing that the system includes, from top to bottom, the carriage driver, the case, the contact carriage having the at least one pressure sensor mounted thereto, the biosensor, an impedance platform of an impedance sensor, and a plurality of electrodes of the impedance sensor;

[0014] Fig. 5 is an exploded assembly bottom view of the system of Fig. 4 showing that the biosensor is illustratively a photoplethysmogram (PPG) sensor;

[0015] Fig. 6 is a bottom view of the system of Fig. 2 showing that a pressure applicator of the contact carriage and the biosensor extend through the impedance platform to contact the skin surface of the user;

[0016] Fig. 7 is a cutaway view of the system of Fig. 2 showing that a portion of the contact carriage is vertically spaced apart from the impedance platform and the carriage driver extends between the top wall of the case and the contact carriage;

[0017] Fig. 8 is a cutaway view of the system of Fig. 2 showing that the contact carriage moves downwardly toward the stationary impedance platform via operation of the carriage driver to change the contact pressure being applied to the skin surface of the user by the pressure applicator of the contact carriage;

[0018] Fig. 9 is a perspective view of an alternative wearable biosensing system fixed to a skin surface of a user, the system including a biosensor configured to measure physiological signals of the user and a controller in communication with the biosensor to receive physiological signal data therefrom;

[0019] Fig. 10 is an enlarged view of the wearable biosensing system of Fig. 9, the wearable biosensing system further including a case having an adhesive material coupled thereto, a contact carriage within the case and mounted for movement relativeto the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, and a contact pressure management unit;

[0020] Fig. 11 is a block diagram of the system of Fig. 10 showing that the biosensor is mounted to the contact carriage for movement therewith, the contact pressure management unit includes at least one pressure sensor also mounted to the contact carriage for movement therewith relative to the case, and the system includes an impedance sensor also mounted to the contact carriage for movement therewith, and further showing that the contact pressure management unit includes a carriage driver coupled with the case and the contact carriage to move the contact carriage, the biosensor, the at least one pressure sensor, and the impedance sensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user;

[0021] Fig. 12 is an exploded assembly top view of the system of Fig. 10 showing that the system includes, from top to bottom, an adhesive material, the carriage driver, the case, the contact carriage having the at least one pressure sensor mounted thereto, the biosensor, an impedance platform of the impedance sensor, and a plurality of electrodes of the impedance sensor;

[0022] Fig. 13 is a bottom view of the system of Fig. 10 showing that a pressure applicator of the contact carriage and the biosensor extend through the impedance platform to contact the skin surface of the user;

[0023] Fig. 14 is a front view of the contact carriage and the impedance sensor of Fig. 12 fixed to one another for movement together relative to the case;

[0024] Fig. 15 is a cutaway view of the system of Fig. 10 showing that the carriage driver extends between the top wall of the case and the contact carriage for movement of the contact carriage;

[0025] Fig. 16 is a cutaway view of the system of Fig. 10 showing that the contact carriage, the biosensor coupled to the contact carriage, and the impedance platform move downwardly via operation of the carriage driver to change the contact pressure being applied to the skin surface of the user by the contact carriage;

[0026] Fig. 17 is a top view of an alternative contact carriage for use with the systems of Fig. 2 or Fig. 9;

[0027] Fig. 18 is a bottom view of the alternative contact carriage of Fig. 17;

[0028] Fig. 19 is a perspective view of an alternative wearable biosensing system fixed to a skin surface of a user, the system including a biosensor configured to measure physiological signals of the user and a controller in communication with the biosensor to receive physiological signal data therefrom;

[0029] Fig. 20 is an enlarged view of the wearable biosensing system of Fig. 19, the wearable biosensing system further including a case having an adhesive material coupled thereto, a contact carriage within the case and mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, and a contact pressure management unit;

[0030] Fig. 21 is a block diagram of the system of Fig. 20 showing that the biosensor is provided by at least one pressure sensor mounted to the contact carriage for movement therewith relative to the case, and further showing that the contact pressure management unit includes a carriage driver coupled with the case and the contact carriage to move the contact carriage and the at least one pressure sensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user;

[0031] Fig. 22 is an exploded assembly top view of the system of Fig. 20 showing that the system includes, from top to bottom, the carriage driver, the case, the adhesive material, a plurality of fasteners, a bridge of the contact carriage having the at least one pressure sensor mounted thereto, a driver platform of the contact carriage, and a pressure applicator of the contact carriage;

[0032] Fig. 23 is an exploded assembly bottom view of the system of Fig. 20 showing that the pressure applicator illustratively includes a first and a second pressure applicator spaced apart from one another;

[0033] Fig. 24 is a perspective view of the system of Fig. 20 fixed to an arm of the user;

[0034] Fig. 25 is a graph showing a waveform of the time difference measured by the pressure sensors of the system of Fig. 20;

[0035] Fig. 26 is a graph showing a pulse wave as detected by the at least one pressure sensor of Fig. 20;

[0036] Fig. 27 is a diagram showing that the system of Figs. 2, 10, and 20 can be placed at different locations on the user;

[0037] Fig. 28 is a diagram showing that a plurality of systems of Figs. 2, 10, and 20 can be placed at different locations on the user at the same time;

[0038] Fig. 29 is a graph showing an average wave shape and amplitude as detected by the biosensor of the systems of Figs. 2 and 10 at different wavelengths and contact pressures;

[0039] Fig. 30 is a graph showing signal-to-noise ratio of the biosensor of Figs. 2 and 10 for different wavelengths and contact pressures;

[0040] Fig. 31 is a graph showing an AC amplitude of the biosensor of Figs. 2 and 10 for different wavelengths and contact pressures;

[0041] Fig. 32 is a graph showing a DC amplitude of the biosensor of Figs. 2 and 10 for different wavelengths and contact pressures;

[0042] Fig. 33 is a graph showing an average wave shape as detected by the impedance sensor of Figs. 2 and 10 at different contact pressures applied to the skin surface;

[0043] Fig. 34 is a graph showing signal-to-noise ratio of the impedance sensor of Figs. 2 and 10 for different contact pressures applied to the skin surface;

[0044] Fig. 35 is a graph showing an AC amplitude of the impedance sensor of Figs. 2 and 10 for different contact pressures applied to the skin surface; and

[0045] Fig. 36 is a graph showing a DC amplitude of the impedance sensor of Figs. 2 and 10 for different contact pressures applied to the skin surface.DETAILED DESCRIPTION OF THE DRAWINGS

[0046] For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.

[0047] The present disclosure provides a wearable biosensing system 10, 210, 310 that is capable of actively monitoring several biomarkers and controlling a contact pressure with a skin surface of a user for more robust signal acquisition. In illustrative embodiments, the system 10, 210, 310 is adhered to the user to reduce motion artifacts that may occur with wearable devices, often banded wearable devices. These motion artifacts occur due to radial and axial motion of the banded wearable device when the user is moving.

[0048] By combining passive contact pressure monitoring and active pressure control, physiological signals provided by the system 10, 210, 310 can be accurately quantified. In-depth signal analysis at different contact pressures and across pressure gradients allows for advanced dynamic detection of biomarkers such as, but not limited to, heart rate, heart rate variability (HRV), respiration rate, blood pressure (BP), cardiovascular performance, vascular tone, vascular assessment, hypo or hyperglycemic events, blood oxygenation (SPO2), among others.

[0049] The system 10, 210, 310 of the present disclosure is also designed to sync with additional systems 10, 210, 310, which can be placed on different body areas, as suggested in Figs. 27 and 28. These multi-location sensors can be used for a more extensive physiological assessment, such as peripheral artery disease.

[0050] Generally, during use of biosensors, physiological signals can change due to user movement, physiological variability with varying applied contact pressure, and probing different signal sources. As a result, biosignal morphology and time domain features can be drastically affected, causing variations in overall waveform shape, magnitude, and time between two signals. To minimize and / or manage a level of motion artifact in physiological signals, the system 10, 210, 310 allows for incremental contact pressure control to optimize the contact pressure applied to the user, as well as associating the contact pressure with physiological signal data to manage motion artifacts within the physiological signal data. Likewise, the system 10, 210, 310 purposely dials into specific contact pressures to look at features that may only be present at that specific contact pressure such that differential analysis may be performed to uncover biomarkers associated with the user.

[0051] The wearable biosensing system 10 disclosed herein includes a case 12, a contact carriage 14, a biosensor 16, and a contact pressure management unit 18, as shown in Figs. 2-4. Illustratively, the system 10 is a wearable device or patch that may be worn by a user. The case 12 is adapted to be fixed to a skin surface of a user, as shown in Fig. 1 . The contact carriage 14 is mounted for movement relative to the case 12 into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user. The biosensor 16 is mounted to the contact carriage 14 for movement therewith relative to the case 12. The contact pressure management unit 18 is configured to adjust the contact pressure being applied to the skin surface by the contact carriage 14 and manage / minimize motion artifacts or other irregularities in thephysiological signal data. The contact pressure management unit 18 includes a carriage driver 20 and at least one pressure sensor 22 mounted for movement with the contact carriage 14.

[0052] The case 12 illustratively houses other components of the system 10 and includes a top wall 24 and a side wall 26 extending downwardly away from the top wall 24, as shown in Fig. 2. The side wall 26 defines a bottom surface 28 adapted to contact the skin surface of the user, as suggested in Fig. 1 . The top wall 24 and the side wall 26 cooperate to define a carriage-receiving space 30, as shown in Fig. 5.

[0053] In some embodiments, the case 12 further includes a flange 32 extending outwardly away from the side wall 26, as shown in Fig. 2. The flange 32 is adapted to contact the skin surface of the user. In some embodiments, the flange 32 is omitted.

[0054] The system 10 further includes an adhesive material 15 configured to adhere the case 12 to the skin surface of the user, as suggested in Fig. 1 . In some embodiments, the adhesive material 15 is provided by wet electrodes, as described in more detail below. In some embodiments, the adhesive material 15 is provided by tape that overlaps with the flange 32 of the case 12 to contact the flange 32 of the case 12 and the skin surface of the user, as shown in Fig. 10. In some embodiments, the adhesive material 15 is provided by double-sided tape. The double-sided tape may be provided on the bottom surface 28 of the side wall 26, for example, in embodiments in which the flange 32 is omitted, or on a bottom surface of the flange 32 and / or the bottom surface 28 of the side wall 26. In some embodiments, the adhesive material 15 is omitted and the case 12 is fixed to the user via a strap.

[0055] The contact carriage 14 is mounted for movement relative to the case 12, as suggested in Figs. 7 and 8, into contact with the skin surface of the user to apply the contact pressure to the skin surface of the user. The contact carriage 14 includes a pressure applicator 34, at least one drive platform 36, and at least one bridge 38, as shown in Figs. 4 and 5. The pressure applicator 34 is configured to apply the contact pressure to the skin surface of the user, as shown in Fig. 8. The at least one drive platform 36 is configured to be driven by the carriage driver 20 to move upwardly and downwardly relative to the top wall 24 of the case 12. The at least one bridge 38 extends between and interconnects the pressure applicator 34 and the at least one drive platform 36. The at least one pressure sensor 22 of the contact pressure management unit 18 is mounted to the at least one bridge 38.

[0056] Illustratively, the at least one bridge 38 includes a first bridge 38A and a second bridge 38B, as shown in Figs. 4 and 5, and the at least one drive platform 36 includes a first drive platform 36A and a second drive platform 36B. The pressure applicator 34 is located between the bridges 38A, 38B. The first bridge 38A interconnects the first drive platform 36A and the pressure applicator 34, and the second bridge 38B interconnects the second drive platform 36B and the pressure applicator 34. The pressure applicator 34 extends downwardly beyond lower surfaces of the drive platforms 36A, 36B and lower surfaces of the bridges 38A, 38B. In this way, the pressure applicator 34 contacts and applies the contact pressure to the skin surface of the user, while the drive platforms 36A, 36B and the bridges 38A, 38B are spaced apart from the skin surface of the user.

[0057] The biosensor 16 is configured to measure physiological signals of the user. In some embodiments, the biosensor 16 is provided by a photoplethysmogram (PPG) sensor. In some embodiments, the biosensor 16 is provided by the at least one pressure sensor 22 such that the biosensor 16 and the at least one pressure sensor 22 are the same component. In some embodiments, the biosensor 16 is provided by any one of or any combination of a PPG sensor, a skin temperature sensor, an ambient temperature sensor, an accelerometer, a gyroscope, an electrocardiogram or a singlesided electrocardiogram (ECG), a micro-electro-mechanical system (MEMS) sensor, an air pressure sensor, or any other suitable sensor. The combination of multiple biosensor 16 types in the system 10 allows for an extensive physiologic assessment of the user.

[0058] In some embodiments, the biosensor 16 contacts the skin surface of the user, as suggested in Fig. 6. The biosensor 16 is coupled to a lower portion of the pressure applicator 34. The biosensor 16 is vertically spaced apart from the drive platforms 36A, 36B and the bridges 38A, 38B such that the biosensor 16 is located closer to the skin surface and farther away from the top wall 24 of the case 12 than the drive platforms 36A, 36B and the bridges 38A, 38B. Physiological signals measured by the biosensor 16 may be used to determine respiration, blood oxygenation, tissue oxygenation, hemoglobin levels, bilirubin levels, biochemical and biophysical information, heart morphology, and / or heart rate, among other biomarkers.

[0059] The contact pressure management unit 18 includes the carriage driver 20, the at least one pressure sensor 22, and a controller 40, as shown in Fig. 3. Thecarriage driver 20 moves the contact carriage 14 and the biosensor 16 relative to the case 12 to change the contact pressure applied by the pressure applicator 34 to the skin surface of the user. The at least one pressure sensor 22 is mounted to the at least one bridge 38 of the contact carriage 14. The controller 40 is in communication with the carriage driver 20, the at least one pressure sensor 22, and the biosensor 16, as shown in Fig. 3.

[0060] The carriage driver 20 is coupled with the top wall 24 of the case 12 and the at least one drive platform 36 of the contact carriage 14 to selectively move the contact carriage 14 and the biosensor 16 relative to the case 12 to adjust the contact pressure applied to the skin surface of the user by the pressure applicator 34 of the contact carriage 14, as shown in Figs. 7 and 8. The carriage driver 20 illustratively includes at least one actuator 42 that extends between the top wall 24 of the case 12 and the at least one drive platform 36.

[0061] In some embodiments, the carriage driver 20 illustratively includes a first actuator 42A and a second actuator 42B spaced apart from the first actuator 42A, as shown in Fig. 4. The first actuator 42A extends through a first hole in the top wall 24 of the case 12 and into a second hole formed in the first drive platform 36A. The second actuator 42B extends through a third hole in the top wall 24 of the case 12 and into a fourth hole formed in the second drive platform 36B. The first actuator 42A and the second actuator 42B move the first drive platform 36A and the second drive platform 36B, respectively, relative to the case 12.

[0062] In some embodiments, the at least one actuator 42 is provided by at least one screw extending through the top wall 24 of the case 12 and into the at least one drive platform 36. In some embodiments, the at least one actuator 42 is provided by a first screw extending through the top wall 24 of the case 12 and into the first drive platform 36A and a second screw extending through the top wall 24 of the case 12 and into the second drive platform 36B. The at least one screw (or the first and second screws) rotate to move the contact carriage 14 relative to the case 12, as suggested in Figs. 7 and 8.

[0063] In some embodiments, the carriage driver 20 comprises at least one motor 46 configured to drive the at least one drive platform 36 relative to the case 12. In some embodiments, the carriage driver 20 comprises a first motor 46A configured to drive the first drive platform 36A and a second motor 46B configured to drive thesecond drive platform 36B. In some embodiments, the first motor 46A is coupled to the first actuator 42A to drive the first actuator 42A, and the second motor 46B is coupled to the second actuator 42B to drive the second actuator 42B, as shown in Figs. 4 and 5.

[0064] In some embodiments, the carriage driver 20 includes at least one bladder configured to move the contact carriage 14 relative to the case 12. In some embodiments, the carriage driver 20 is provided by a strap that is tightened or loosened to change the contact pressure applied to the skin surface of the user by the pressure applicator 34.

[0065] The at least one pressure sensor 22 is configured to output pressure data suitable for determining the contact pressure developed between the pressure applicator 34 of the contact carriage 14 and the skin surface of the user. In some embodiments, the at least one pressure sensor 22 is provided by at least one strain gauge. In such an embodiment, the biosensor 16 may be provided by the at least one strain gauge.

[0066] In some embodiments, the at least one pressure sensor 22 is provided by a force resistive sensor. In such an embodiment, the force resistive sensor is coupled to the pressure applicator 34.

[0067] In some embodiments, the at least one pressure sensor 22 includes a first pressure sensor 22A and a second pressure sensor 22B, as shown in Figs. 4 and 5. In such an embodiment, the first pressure sensor 22A may be provided by a first strain gauge and the second pressure sensor 22B may be provided by a second strain gauge. In such an embodiment, the first strain gauge is coupled to the first bridge 38A of the contact carriage 14 and the second strain gauge is coupled to the second bridge 38B of the contact carriage 14.

[0068] The controller 40 is in communication with the at least one pressure sensor 22 to receive pressure data therefrom and in communication with the biosensor 16 to receive physiological signal data therefrom, as suggested in Fig. 3. The controller 40 includes a memory 48, a processor 50, and a user interface 52, as shown in Fig. 3. The controller 40 stores the pressure data from the at least one pressure sensor 22 and the physiological signal data from the biosensor 16 in the memory 48 thereof. The processor 50 may use the pressure data to determine the contact pressure between the pressure applicator 34 and the skin surface of the user. The processor 50, usinginstructions stored in the memory 48, associates the contact pressure developed between the pressure applicator 34 and the skin surface with the physiological signal data from the biosensor 16. The association of the contact pressure with the physiological signal data allows for the management of motion artifacts and other irregularities in the physiological signal data. In other words, the contact pressure is used to optimize and improve the physiological signal data.

[0069] For example, the contact pressure is used to calculate, determine, and / or detect biological parameters and biomarkers within the physiological signal data that determine ailments and relative health states of the user. The contact pressure impacts the morphology of the physiological signal such that the contact pressure should be associated with and used when interpreting the physiological signal data. Thus, the contact pressure may be used to better show the user’s physiological state.

[0070] Biosensors that measure similar physiological events through different anatomical mediums are affected by contact pressure differently, which gives way to differential features that identify biomarkers when comparing two signals across a contact pressure gradient and / or when measuring at a single controlled contact pressure. Thus, the controller 40 accounts for the contact pressure when analyzing the physiological signal data for biomarkers. After associating the physiological signal data with the contact pressure, it may be determined that the biomarker detected is in fact a true biomarker, or it may be determined that the biomarker detected is an artifact due to the contact pressure variability (i.e., a false positive biomarker).

[0071] The processor 50 also, using instructions stored in the memory 48, uses the contact pressure as an input for adjustments to operation of the carriage driver 20. The controller 40 is configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver 20. In some embodiments, the optimized contact pressure is based, at least in part, on a desired biomarker for identification or study. In some embodiments, the optimized contact pressure is based, at least in part, on the pressure data received from the at least one pressure sensor 22 and / or the physiological signal data received from the biosensor 16.

[0072] The processor 50 of the controller 40 may compare the contact pressure developed between the pressure applicator 34 and the skin surface with the optimized contact pressure to determine the instruction. For example, the pressure data from theat least one pressure sensor 22 may indicate that the contact pressure applied to the user by the pressure applicator 34 is less (or more) than the optimized contact pressure for improved physiological signal data output from the biosensor 16. The processor 50 may analyze the physiological signal data to determine a level of noise in the data. If the level of noise is greater than a threshold, the instruction may indicate that the contact pressure should be adjusted to decrease the level of noise.

[0073] The instruction associated with the optimized contact pressure may be used for alignment of the contact pressure to the optimized contact pressure. For example, if the pressure data indicates that the contact pressure applied to the user by the pressure applicator 34 is less than desirable, the instruction may indicate that the contact pressure should be increased so that the contact pressure aligns with the optimized contact pressure. To align the contact pressure with the optimized contact pressure, the carriage driver 20 drives the at least one drive platform 36 away from the top wall 24 of the case 12 to increase the contact pressure between the pressure applicator 34 and the user, as suggested in Fig. 7.

[0074] The controller 40 is configured to output the instruction associated with the optimized contact pressure to the user interface 52 so that the user is informed of the instruction associated with the optimized contact pressure. In some embodiments, the instruction may comprise a visual indicator. For example, the visual indicator may include a color, a phrase, an image, or a combination of the same. In some embodiments, the instruction may comprise an auditory indicator. Based on the instruction, the user may manually adjust the carriage driver 20.

[0075] As one example, if the user interface 52 depicts a visual indicator, such as a red light, the user is informed that the contact pressure is not aligned with the optimized contact pressure. Then, the user may rotate the at least one screw of the carriage driver 20 to move the contact carriage 14 downwardly away from the top wall 24 of the case 12, thereby aligning the contact pressure with the optimized contact pressure.

[0076] In some embodiments, the controller 40 is in communication with the carriage driver 20 to provide for automatic adjustment of the contact carriage 14 via the carriage driver 20 without user involvement. The controller 40 is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver 20. Based on the instruction, the carriage driver 20 moves the contactcarriage 14. The carriage driver 20 is configured to provide infinitely variable adjustment of the contact carriage 14 so that the contact pressure matches the optimized contact pressure.

[0077] The user interface 52 may also display alerts or warnings to the user based on a detected biomarker. For example, the user interface 52 may display a visual indicator to notify the user of an alert or a warning.

[0078] The system 10 further includes an impedance sensor 54 configured to output bioimpedance measurements of the user, as shown in Figs. 3-5. The impedance sensor 54 includes an insulative platform 56 and a plurality of electrodes 58 coupled to a bottom surface of the insulative platform 56 that faces away from the top wall 24 of the case 12.

[0079] The insulative platform 56 is mounted to the case 12, as suggested in Fig. 3. At least one fastener 57 extends through a first hole in the side wall 26 of the case 12 and into a second hole of the insulative platform 56 to fix the insulative platform 56 relative to the case 12. In some embodiments, a first fastener extends through the first hole in the side wall 26 of the case 12 and into the second hole of the insulative platform 56, and a second fastener extends through a third hole in the side wall 26 of the case 12 spaced apart from the first hole and into a fourth hole of the insulative platform 56 spaced apart from the second hole.

[0080] The at least one drive platform 36 and the at least one bridge 38 of the contact carriage 14 are located between the top wall 24 of the case 12 and the insulative platform 56 of the impedance sensor 54, as suggested in Fig. 4 and shown in Fig. 7. The insulative platform 56 of the impedance sensor 54 is formed to define an applicator-receiving hole 60 that extends entirely vertically through the insulative platform 56, as shown in Figs. 4 and 5. The pressure applicator 34 of the contact carriage 14 is positioned to extend through the applicator-receiving hole 60 and move within the applicator-receiving hole 60, as suggested in Fig. 8.

[0081] The plurality of electrodes 58 are coupled to the bottom surface of the insulative platform 56 such that the plurality of electrodes 58 are positioned adjacent the skin surface of the user, as suggested in Fig. 6. Illustratively, the plurality of electrodes 58 includes four electrodes. In other embodiments, the plurality of electrodes 58 may include any number of electrodes. As shown in Fig. 6, the plurality of electrodes 58 do not overlap with the applicator-receiving hole 60 of the insulativeplatform 56. In this way, the plurality of electrodes 58 do not overlap or cover the pressure applicator 34 or the biosensor 16 coupled thereto such that the pressure applicator 34 and the biosensor 16 make direct contact with the skin surface of the user.

[0082] In some embodiments, each of the plurality of electrodes 58 is a wet electrode. In such an embodiment, the wet electrodes provide the adhesive material 15 to fix the case 12 to the user. In some embodiments, the wet electrodes supplement the adhesive material 15 to aid in fixing the case 12 to the user.

[0083] The contact carriage 14 (and the biosensor 16 and the at least one pressure sensor 22 coupled to the contact carriage 14) moves relative to the case 12 and the impedance sensor 54, as shown in Figs. 7 and 8. The at least one drive platform 36 and the at least one bridge 38 are spaced apart from a top surface of the insulative platform 56 while the contact carriage 14 is in an initial state, as shown in Fig. 7. While in the initial state, a bottom surface of the plurality of electrodes 58 and a bottom surface of the pressure applicator 34 may be substantially aligned, as shown in Fig. 7. To adjust the contact pressure applied to the skin surface by the pressure applicator 34, the carriage driver 20 moves the contact carriage 14 (and the biosensor 16 and the at least one pressure sensor 22 coupled thereto) downwardly toward the skin surface to a displaced state. It will be understood that there are an infinite number of displaced states as the carriage driver 20 allows for incremental adjustment of the contact carriage 14.

[0084] In the displaced state, as shown in Fig. 8, the at least one drive platform 36 and the at least one bridge 38 move toward the insulative platform 56. For example, in some embodiments, the at least one drive platform 36 and the at least one bridge 38 contact and / or engage the top surface of the insulative platform 56 such that the at least one drive platform 36 and the at least one bridge 38 are not spaced apart from the top surface of the insulative platform 56. Also in the displaced state, the pressure applicator 34 moves downwardly while the plurality of electrodes 58 remain fixed relative to the case 12. The bottom surface of the plurality of electrodes 58 and the bottom surface of the pressure applicator 34 are not aligned while the contact carriage 14 is in the displaced state. Instead, the bottom surface of the pressure applicator 34 is below the bottom surface of the plurality of electrodes 58, as shown in Fig. 8.

[0085] Wet electrodes are not highly impacted by contact pressure. Because of this, the plurality of electrodes 58 is fixed relative to the case 12 and does not move with the contact carriage 14 during the adjustment of the contact pressure being applied to the skin surface of the user.

[0086] The controller 40 is in communication with the impedance sensor 54 to receive the bioimpedance measurements of the user therefrom, as shown in Fig. 3. The controller 40 stores the bioimpedance measurements from the impedance sensor 54 in the memory 48 thereof. The processor 50, using instructions stored in the memory 48, associates the contact pressure with the bioimpedance measurements from the impedance sensor 54, as previously described in relation to the physiological signal data. The association of the contact pressure with the bioimpedance measurements allows for managing of motion artifacts and other irregularities in the bioimpedance measurements. In other words, the contact pressure is used to optimize and improve the bioimpedance measurements. The optimized contact pressure determined by the controller 40, as previously described, may also be based, at least in part, on the bioimpedance measurements received from the impedance sensor 54.

[0087] Illustratively, the impedance sensor 54 may be a bioimpedance (BioZ) sensor. The bioimpedance measurements from the impedance sensor 54 may be used to determine skin hydration, perspiration levels, fat content of tissue, water content of tissue, and / or electrocardiogram (ECG), among others.

[0088] The controller 40 is in communication with the impedance sensor 54 such that the controller 40 may instruct the impedance sensor 54 to apply current to the user via the plurality of electrodes 58. The voltage detected across the plurality of electrodes 58 may be used to determine the bioimpedance measurements.

[0089] Another embodiment of a wearable biosensing system 210 is shown in Figs. 9-16. The wearable biosensing system 210 is substantially similar to the wearable biosensing system 10 shown in Figs. 1-8 and described herein. Accordingly, similar reference numbers in the 200 series indicate features that are common between the wearable biosensing system 210 and the wearable biosensing system 10. The description of the wearable biosensing system 10 is incorporated by reference to apply to the wearable biosensing system 210, expect in instances when it conflicts with the specific description and the drawings of the wearable biosensing system 210.

[0090] The wearable biosensing system 210 disclosed herein includes a case 212, a contact carriage 214, a biosensor 216, and a contact pressure management unit 218, as shown in Figs. 11 and 12. The case 212 is adapted to be fixed to a skin surface of a user, as shown in Fig. 9. The contact carriage 214 is mounted for movement relative to the case 212 into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user. The biosensor 216 is mounted to the contact carriage 214 for movement therewith relative to the case 212. The contact pressure management unit 218 is configured to adjust the contact pressure being applied to the skin surface by the contact carriage 214 and manage / minimize motion artifacts or other irregularities in physiological signal data. The contact pressure management unit 218 includes a carriage driver 220 and at least one pressure sensor 222 mounted for movement with the contact carriage 214.

[0091] The case 212 includes a top wall 224 and a side wall 226 extending downwardly away from the top wall 224, as shown in Fig. 10. The side wall 226 defines a bottom surface 228 adapted to contact the skin surface of the user, as suggested in Fig. 9.

[0092] In some embodiments, the case 212 further includes a flange 232 extending outwardly away from the side wall 226, as shown in Figs. 10 and 12. The flange 232 is also adapted to contact the skin surface of the user. In some embodiments, the flange 232 is omitted.

[0093] The system 210 further includes an adhesive material 215 configured to adhere the case 212 to the skin surface of the user, as suggested in Fig. 9. In some embodiments, the adhesive material 215 is provided by tape that overlaps with the flange 232 of the case 212 to contact the flange 232 of the case 212 and the skin surface of the user, as shown in Fig. 10. In some embodiments, the adhesive material 215 is provided by double-sided tape. The double-sided tape may be provided on the bottom surface 228 of the side wall 226, for example, in embodiments in which the flange 232 is omitted, or on a bottom surface of the flange 232 and / or the bottom surface 228 of the side wall 226. In some embodiments, the adhesive material 215 is omitted and the case 212 is fixed to the user via a strap.

[0094] The contact carriage 214 is mounted for movement relative to the case 212, as suggested in Figs. 15 and 16, into contact with the skin surface of the user to apply the contact pressure to the skin surface of the user. The contact carriage 214includes a pressure applicator 234, at least one drive platform 236, and at least one bridge 238, as shown in Fig. 12. The pressure applicator 234 is configured to apply the contact pressure to the skin surface of the user, as shown in Fig. 16. The at least one drive platform 236 is configured to be driven by the carriage driver 220 to move upwardly and downwardly relative to the top wall 224 of the case 212. The at least one bridge 238 extends between and interconnects the pressure applicator 234 and the at least one drive platform 236. The at least one pressure sensor 222 of the contact pressure management unit 218 is mounted to the at least one bridge 238.

[0095] The biosensor 216 is configured to measure physiological signals of the user. In some embodiments, the biosensor 216 is provided by a photoplethysmogram (PPG) sensor. In some embodiments, the biosensor 216 is provided by the at least one pressure sensor 222 such that the biosensor 216 and the at least one pressure sensor 222 are the same component. In some embodiments, the biosensor 216 is provided by any one of or any combination of a PPG sensor, a skin temperature sensor, an ambient temperature sensor, an accelerometer, a gyroscope, an electrocardiogram or a single-sided electrocardiogram (ECG), a micro-electro-mechanical system (MEMS) sensor, an air pressure sensor, or any other suitable sensor.

[0096] In some embodiments, the biosensor 216 contacts the skin surface of the user, as suggested in Fig. 13. The biosensor 216 is coupled to a lower portion of the pressure applicator 234. The biosensor 216 is vertically spaced apart from the at least one drive platform 36 and the at least one bridge 38 such that the biosensor 216 is located closer to the skin surface and farther away from the top wall 224 of the case 212 than the at least one drive platform 36 and the at least one bridge 38.

[0097] The contact pressure management unit 218 includes the carriage driver 220, the at least one pressure sensor 222, and a controller 240, as shown in Fig. 11 . The carriage driver 220 moves the contact carriage 214, the biosensor 216, and the at least one pressure sensor 222 relative to the case 212 to change the contact pressure applied by the pressure applicator 234 to the skin surface of the user. The at least one pressure sensor 222 is mounted to the at least one bridge 238 of the contact carriage 214. The controller 240 is in communication with the carriage driver 220, the at least one pressure sensor 222, and the biosensor 216, as shown in Fig. 1 1 .

[0098] The carriage driver 220 is coupled with the top wall 224 of the case 212 and the at least one drive platform 236 of the contact carriage 214 to selectively movethe contact carriage 214 and the biosensor 216 relative to the case 212 to adjust the contact pressure applied to the skin surface of the user by the pressure applicator 234 of the contact carriage 214, as shown in Figs. 15 and 16. The carriage driver 220 illustratively includes at least one actuator 242 that extends between the top wall 224 of the case 212 and the at least one drive platform 236.

[0099] The at least one pressure sensor 222 is configured to output pressure data suitable for determining the contact pressure developed between the pressure applicator 234 of the contact carriage 214 and the skin surface of the user. In some embodiments, the at least one pressure sensor 222 includes a first pressure sensor 222A and a second pressure sensor 222B, as shown in Fig. 12. In some embodiments, the at least one pressure sensor 222 is provided by at least one strain gauge. In such embodiments, the biosensor 216 may be provided by the at least one strain gauge.

[0100] In some embodiments, the at least one pressure sensor 222 is provided by a force resistive sensor. In such an embodiment, the force resistive sensor is coupled to the pressure applicator 234.

[0101] The controller 240 is in communication with the at least one pressure sensor 222 to receive pressure data therefrom and in communication with the biosensor 216 to receive physiological signal data therefrom, as suggested in Fig. 11 . The controller 240 includes a memory 248, a processor 250, and a user interface 252, as shown in Fig. 11 . The controller 240 stores the pressure data from the at least one pressure sensor 222 and the physiological signal data from the biosensor 216 in the memory 248 thereof. The processor 250 may use the pressure data to determine the contact pressure between the pressure applicator 234 and the skin surface of the user. The processor 250, using instructions stored in the memory 248, associates the contact pressure developed between the pressure applicator 234 and the skin surface with the physiological signal data from the biosensor 216. The association of the contact pressure with the physiological signal data allows for the management of motion artifacts and other irregularities in the physiological signal data.

[0102] The processor 250 also, using instructions stored in the memory 248, uses the contact pressure as an input for adjustments to operation of the carriage driver 220. The controller 240 is configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver220. The optimized contact pressure is based, at least in part, on the pressure data received from the at least one pressure sensor 222 and / or the physiological signal data received from the biosensor 216.

[0103] The processor 250 of the controller 240 may compare the contact pressure developed between the pressure applicator 234 and the skin surface with the optimized contact pressure to determine the instruction. For example, the pressure data from the at least one pressure sensor 222 may indicate that the contact pressure applied to the user by the pressure applicator 234 is less (or more) than the optimized contact pressure for improved physiological signal data output from the biosensor 216. The processor 250 may analyze the physiological signal data to determine a level of noise in the data. If the level of noise is greater than a threshold, the instruction may indicate that the contact pressure should be adjusted to decrease the level of noise.

[0104] The instruction associated with the optimized contact pressure may be used for alignment of the contact pressure to the optimized contact pressure. For example, if the pressure data indicates that the contact pressure applied to the user by the pressure applicator 234 is less than desirable, the instruction may indicate that the contact pressure should be increased so that the contact pressure aligns with the optimized contact pressure. To align the contact pressure with the optimized contact pressure, the carriage driver 220 drives the at least one drive platform 236 away from the top wall 224 of the case 212 to increase the contact pressure between the pressure applicator 234 and the user, as suggested in Fig. 16.

[0105] The controller 240 is configured to output the instruction associated with the optimized contact pressure to the user interface 252 so that the user is informed of the instruction associated with the optimized contact pressure. Based on the instruction, the user may manually adjust the carriage driver 220 to align the contact pressure with the optimized contact pressure.

[0106] In some embodiments, the controller 240 is in communication with the carriage driver 220 to provide for automatic adjustment of the contact carriage 214 via the carriage driver 220 without user involvement. The controller 240 is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver 220. Based on the instruction, the carriage driver 220 moves the contact carriage 214. The carriage driver 220 is configured to provide infinitely variableadjustment of the contact carriage 214 so that the contact pressure matches the optimized contact pressure.

[0107] The system 210 further includes an impedance sensor 254 configured to output bioimpedance measurements of the user, as shown in Figs. 11 and 12. The impedance sensor 254 includes an insulative platform 256 and a plurality of electrodes 258 coupled to a bottom surface of the insulative platform 256 that faces away from the top wall 224 of the case 212.

[0108] The at least one drive platform 236 and the at least one bridge 238 of the contact carriage 214 are located between the top wall 224 of the case 212 and the insulative platform 256 of the impedance sensor 254, as suggested in Fig. 12 and shown in Fig. 15. The insulative platform 256 of the impedance sensor 254 is formed to define an applicator-receiving hole 260 that extends entirely vertically through the insulative platform 256, as shown in Fig. 12. The pressure applicator 234 of the contact carriage 214 is positioned in the applicator-receiving hole 260, as shown in Fig. 14.

[0109] The insulative platform 256 is fixed to the contact carriage 214, as shown in Fig. 14. In some embodiments, the pressure applicator 234 is mounted to surfaces of the applicator-receiving hole 260 of the insulative platform 256. The impedance sensor 254, thus, moves with the contact carriage 214 relative to the case 212, as shown in Figs. 15 and 16.

[0110] The plurality of electrodes 258 are coupled to the bottom surface of the insulative platform 256 such that the plurality of electrodes 258 are positioned adjacent the skin surface of the user, as suggested in Fig. 13. Illustratively, the plurality of electrodes 258 includes four electrodes. In other embodiments, the plurality of electrodes 258 may include any number of electrodes. As shown in Fig. 13, the plurality of electrodes 258 do not overlap with the applicator-receiving hole 260 of the insulative platform 256. In this way, the plurality of electrodes 258 do not overlap or cover the pressure applicator 234 or the biosensor 216 coupled thereto such that the pressure applicator 234 and the biosensor 216 make direct contact with the skin surface of the user.

[0111] In some embodiments, each of the plurality of electrodes 258 is a dry electrode. In such an embodiment, the dry electrodes do not provide the adhesive material to fix the case 12 to the user. Thus, the adhesive material 215 is included in the system 210 to fix the case 212 to the user.

[0112] The contact carriage 214 (and the biosensor 216 and the at least one pressure sensor 222 and the impedance sensor 254 all coupled to the contact carriage 214) moves relative to the case 212, as shown in Figs. 15 and 16. While the contact carriage 214 is in an initial state, as shown in Fig. 15, the pressure applicator 234 and the plurality of electrodes 258 extend below the bottom surface of the side wall 226 and the flange 232 of the case 212 a first distance. A bottom surface of the plurality of electrodes 258 and a bottom surface of the pressure applicator 234 are substantially aligned, as shown in Fig. 15. To adjust the contact pressure applied to the skin surface by the pressure applicator 234, the carriage driver 220 moves the contact carriage 214 (and the biosensor 216 and the at least one pressure sensor 222 and the impedance sensor 254 all coupled thereto) downwardly toward the skin surface to a displaced state. It will be understood that there are an infinite number of displaced states as the carriage driver 220 allows for incremental adjustment of the contact carriage 214.

[0113] In the displaced state, as shown in Fig. 16, the pressure applicator 234 and the plurality of electrodes 258 move downwardly together. The bottom surface of the plurality of electrodes 258 and the bottom surface of the pressure applicator 234 are still substantially aligned while the contact carriage 214 is in the displaced state. In this way, the plurality of electrodes 258 and the pressure applicator 234 apply the contact pressure to the skin surface of the user.

[0114] Dry electrodes are impacted by contact pressure. Because of this, the plurality of electrodes 258 moves relative to the case 12 with the contact carriage 214 during the adjustment of the contact pressure being applied to the skin surface of the user.

[0115] The controller 240 is in communication with the impedance sensor 254 to receive the bioimpedance measurements of the user therefrom, as shown in Fig. 11 . The controller 240 stores the bioimpedance measurements from the impedance sensor 254 in the memory 248 thereof. The processor 250, using instructions stored in the memory 248, associates the contact pressure with the bioimpedance measurements from the impedance sensor 254, as previously described in relation to the physiological signal data. The association of the contact pressure with the bioimpedance measurements allows for managing of motion artifacts and other irregularities in the bioimpedance measurements. The optimized contact pressure determined by thecontroller 240, as previously described, may also be based, at least in part, on the bioimpedance measurements received from the impedance sensor 254.

[0116] Another embodiment of a contact carriage 214' for use with the system 10 of Figs. 1 -8 and the system 210 of Figs. 9-16 is shown in Figs. 17 and 18. The contact carriage 214' is substantially similar to the contact carriage 14 shown in Figs. 1-8 and described herein and the contact carriage 214 shown in Figs. 9-16 and described herein. Accordingly, similar reference numbers in the 200 series with a prime symbol indicate features that are common between the contact carriage 214’ and the contact carriage 14, 214. The description of the contact carriage 14, 214 is incorporated by reference to apply to the contact carriage 214', expect in instances when it conflicts with the specific description and the drawings of the contact carriage 214'.

[0117] The contact carriage 214' includes a pressure applicator 234' (a portion of which is not shown, but identical to the previously described pressure applicator 34, 234), at least one drive platform 236', and at least one bridge 238', as shown in Figs. 17 and 18. The pressure applicator 234' is configured to apply the contact pressure to the skin surface of the user (see Figs. 4 and 12). The at least one drive platform 236' is configured to be driven by the carriage driver 20, 220. The at least one bridge 238' extends between and interconnects the pressure applicator 234' and the at least one drive platform 236'. The at least one pressure sensor 22, 222 of the contact pressure management unit 18, 218 is mounted to the at least one bridge 238'.

[0118] Illustratively, the at least one bridge 238' includes a first bridge 238A' and a second bridge 238B', as shown in Figs. 17 and 18, and the at least one drive platform 236' includes a first drive platform 236A' and a second drive platform 236B'. The pressure applicator 234' is located between the bridges 238A’, 238B'. The first bridge 238A' interconnects the first drive platform 236A’ and the pressure applicator 234' and the pressure applicator 234' and the second drive platform 236B'. The second bridge 238B' interconnects the second drive platform 236B' and the pressure applicator 234' and the pressure applicator 234' and the first drive platform 236A'.

[0119] Another embodiment of a wearable biosensing system 310 is shown in Figs. 19-23. The wearable biosensing system 310 is substantially similar to the wearable biosensing system 10 and the wearable biosensing system 210. Accordingly, similar reference numbers in the 300 series indicate features that are commonbetween the wearable biosensing system 310 and the wearable biosensing system 10, 210. The description of the wearable biosensing system 10, 210 is incorporated by reference to apply to the wearable biosensing system 310, expect in instances when it conflicts with the specific description and the drawings of the wearable biosensing system 310.

[0120] The wearable biosensing system 310 disclosed herein includes a case 312, a contact carriage 314, a biosensor 316, and a contact pressure management unit 318, as shown in Figs. 21 and 22. The case 312 is adapted to be fixed to a skin surface of a user, as shown in Fig. 19. The contact carriage 314 is mounted for movement relative to the case 312 into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user. The biosensor 316 is mounted to the contact carriage 314 for movement therewith relative to the case 312. The contact pressure management unit 318 is configured to adjust the contact pressure being applied to the skin surface by the contact carriage 314 and manage / minimize motion artifacts or other irregularities in physiological signal data. The contact pressure management unit 318 includes a carriage driver 320 and at least one pressure sensor 322 mounted for movement with the contact carriage 314.

[0121] The case 312 includes a top wall 324 and a side wall 326 extending downwardly away from the top wall 324, as shown in Fig. 20. The side wall 326 defines a bottom surface 328 adapted to contact the skin surface of the user, as suggested in Fig. 19.

[0122] In some embodiments, the case 312 further includes a flange 332 extending outwardly away from the side wall 326, as shown in Figs. 20 and 22. The flange 332 is also adapted to contact the skin surface of the user. In some embodiments, the flange 332 is omitted.

[0123] The system 310 further includes an adhesive material 315 configured to adhere the case 312 to the skin surface of the user, as suggested in Fig. 19. In some embodiments, the adhesive material 315 is provided by tape that overlaps with the flange 332 of the case 312 to contact the flange 332 of the case 312 and the skin surface of the user. In some embodiments, the adhesive material 315 is provided by double-sided tape, as shown in Figs. 20 and 22. The double-sided tape may be provided on the bottom surface 328 of the side wall 326, for example, in embodiments in which the flange 332 is omitted, or on a bottom surface of the flange 332 and / or thebottom surface 328 of the side wall 326. In some embodiments, the adhesive material 315 is omitted and the case 312 is fixed to the user via a strap.

[0124] The contact carriage 314 is mounted for movement relative to the case 312, as suggested in Fig. 21 , into contact with the skin surface of the user to apply the contact pressure to the skin surface of the user. The contact carriage 314 includes a pressure applicator 334, at least one drive platform 336, and at least one bridge 338, as shown in Fig. 22. The pressure applicator 334 is configured to apply the contact pressure to the skin surface of the user. The at least one drive platform 336 is configured to be driven by the carriage driver 320 to move upwardly and downwardly relative to the top wall 324 of the case 312. The at least one bridge 338 extends between and interconnects the pressure applicator 334 and the at least one drive platform 336. The at least one pressure sensor 322 of the contact pressure management unit 318 is mounted to the at least one bridge 338.

[0125] In some embodiments, the pressure applicator 334 includes two pressure applicators 334 spaced apart from one another, as shown in Fig. 22. In some embodiments, the at least one bridge 338 includes two bridges 338. The bridges 338 are coupled to the at least one drive platform 336 via a plurality of fasteners. The two pressure applicators 334 are coupled to the two bridges 338 (one to each bridge 338) via the plurality of fasteners.

[0126] Illustratively, the biosensor 316 is provided by the at least one pressure sensor 322 such that the biosensor 316 and the at least one pressure sensor 322 are the same component. The at least one pressure sensor 322 is configured to measure physiological signals of the user.

[0127] The contact pressure management unit 318 includes the carriage driver 320, the at least one pressure sensor 322, and a controller 340, as shown in Fig. 21 . The carriage driver 320 moves the contact carriage 314 and the at least one pressure sensor 322 relative to the case 312 to change the contact pressure applied by the pressure applicator 334 to the skin surface of the user. The at least one pressure sensor 322 is mounted to the at least one bridge 338 of the contact carriage 314. The controller 340 is in communication with the carriage driver 320 and the at least one pressure sensor 322, as shown in Fig. 21 .

[0128] The carriage driver 320 is coupled with the top wall 324 of the case 312 and the at least one drive platform 336 of the contact carriage 314 to selectively movethe contact carriage 314 and the at least one pressure sensor 322 relative to the case 312 to adjust the contact pressure applied to the skin surface of the user by the pressure applicator 334 of the contact carriage 314. The carriage driver 320 illustratively includes at least one actuator 342 that extends between the top wall 324 of the case 312 and the at least one drive platform 336.

[0129] The at least one pressure sensor 322 is configured to output pressure data suitable for determining the contact pressure developed between the pressure applicator 334 of the contact carriage 314 and the skin surface of the user. The at least one pressure sensor 322 also outputs the physiological signal data. In illustrative embodiments, the at least one pressure sensor 322 is provided by at least one strain gauge. In some embodiments, the at least one pressure sensor 322 illustratively includes four strain gauges, as shown in Fig. 22.

[0130] The controller 340 is in communication with the at least one pressure sensor 322 to receive pressure data and physiological signal data therefrom, as suggested in Fig. 21 . The controller 340 includes a memory 348, a processor 350, and a user interface 352, as shown in Fig. 21 . The controller 340 stores the pressure data and the physiological signal data from the at least one pressure sensor 322 in the memory 348 thereof. The processor 350 may use the pressure data to determine the contact pressure between the pressure applicator 334 and the skin surface of the user. The processor 350, using instructions stored in the memory 348, associates the contact pressure developed between the pressure applicator 334 and the skin surface with the physiological signal data from the at least one pressure sensor 322. The association of the contact pressure with the physiological signal data allows for the management of motion artifacts and other irregularities in the physiological signal data.

[0131] The processor 350 also, using instructions stored in the memory 348, uses the contact pressure as an input for adjustments to operation of the carriage driver 320. The controller 340 is configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver 320. The optimized contact pressure is based, at least in part, on the pressure data received from the at least one pressure sensor 322 and / or the physiological signal data received from the at least one pressure sensor 322.

[0132] The processor 350 of the controller 340 may compare the contact pressure developed between the pressure applicator 334 and the skin surface with theoptimized contact pressure to determine the instruction. For example, the pressure data from the at least one pressure sensor 322 may indicate that the contact pressure applied to the user by the pressure applicator 334 is less (or more) than the optimized contact pressure for improved physiological signal data output from the at least one pressure sensor 322. The instruction associated with the optimized contact pressure may be used for alignment of the contact pressure to the optimized contact pressure.

[0133] The controller 340 is configured to output the instruction associated with the optimized contact pressure to the user interface 352 so that the user is informed of the instruction associated with the optimized contact pressure. Based on the instruction, the user may manually adjust the carriage driver 320 to align the contact pressure with the optimized contact pressure.

[0134] In some embodiments, the controller 340 is in communication with the carriage driver 320 to provide for automatic adjustment of the contact carriage 314 via the carriage driver 320 without user involvement. The controller 340 is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver 320. Based on the instruction, the carriage driver 320 moves the contact carriage 314. The carriage driver 320 is configured to provide infinitely variable adjustment of the contact carriage 314 so that the contact pressure matches the optimized contact pressure.

[0135] As shown in Fig. 24, the system 310 is adhered to an arm of the user. Illustratively, the two strain gauges 322 on the first bridge 338 act as a proximal pressure sensor and the two strain gauges 322 on the second bridge 338 act as a distal pressure sensor. The pressure sensors 322 are configured to output physiological signal data for calculation of a differential pressure between the inside of the body (blood pressure) and the applied contact pressure. The two pressure sensors 322 allow the system 310 to calculate pulse transit time, which is strongly correlated with blood pressure. Fig. 25 depicts the waveform measured by the pressure sensors 322 and the different arrival times due to the sensor locations (i.e., proximal and distal). Fig. 26 shows a complete waveform from one of the pressure sensors 322. The DC portion of the signal represents the contact pressure, and the AC portion of the signal represents the pulse wave, which contains additional information about blood pressure. By using strain gauges as the at least one pressure sensor 322 and thebiosensor 316, blood pressure, heart rate, and / or heart rate variability of the user may be determined without the use of a more traditional biosensor.

[0136] As shown in Fig. 27, the systems 10, 210, 310 may be adhered at multiple different locations on the body of the user. Exemplary locations are shown in Fig. 27. As shown in Fig. 28, a plurality of systems 10, 210, 310 may be adhered to the user for a more complete signal analysis. The systems 10, 210, 310 may be synced to one another (i.e. , in communication with the same controller 40, 240, 340).

[0137] Fig. 29 depicts wave shapes as detected by the biosensor 16, 216 at different wavelengths (i.e., red light at 655 nm, infrared (IR) light at 940 nm, and green light at 530 nm) and contact pressures. The signal morphology changes based on the contact pressure. For example, as shown in the left column (red PPG sensor), the signal morphology with greatest variability is at 40 mmHg. The signal morphology is most consistent at 10 mmHg. As shown in the middle column (IR PPG sensor), the signal morphology with greatest variability is at 40 mmHg. The signal morphology is most consistent at 10 mmHg. As shown in the right column (green PPG sensor), the signal morphology with greatest variability is at 0 mmHg. The signal morphology is most consistent at 10 mmHg.

[0138] Fig. 30 depicts a signal-to-noise ratio (SNR) for the biosensor 16, 216 at different wavelengths and contact pressures. The best SNR for red light and IR light is around 10 mmHg, and the best SNR for green light is around 40 mmHg. The different wavelengths penetrate differently in the body and the features that the wavelengths interact with change morphology differently as a function of pressure.

[0139] Fig. 31 depicts an AC amplitude for the biosensor 16, 216 at different wavelengths and contact pressures. The AC amplitude varies according to the wavelength with the greatest AC amplitude for all the wavelengths around 0 mmHg.

[0140] Fig. 32 depicts a DC amplitude for the biosensor 16, 216 at different wavelengths and at different contact pressures. The DC amplitude varies according to the wavelength with the greatest DC amplitude for red light and IR light around 10 to 20 mmHg, and the greatest DC amplitude for green light around 40 mmHg. The greater the DC amplitude often results in a lower AC amplitude. However, this may not always be the case. The DC amplitude is a result of the biosensor 16, 216 interacting with more anatomy and non-pulsatile components of the body. AC and DC values are used to calculate the SNR, which often correlates to the best signal morphology, whichis important for determining biomarkers. It is also important to know what contact pressures to apply to the skin surface to gain a specific feature of the morphology so biomarkers can be analyzed.

[0141] Fig. 33 depicts an average wave shape as detected by the impedance sensor 54, 254 for different contact pressures applied to the skin surface. Increasing contact pressure reduces signal variability and increases morphological features. Knowing this information helps to control the contact pressure to give specific morphologies that can amplify features associated with biomarkers.

[0142] Fig. 34 depicts a signal-to-noise ratio (SNR) for the impedance sensor 54, 254 for different contact pressures applied to the skin surface. The SNR is important to evaluating biomarkers. Higher contact pressures reveal specific morphological features as a result of increased SNR.

[0143] Fig. 35 depicts an AC amplitude for the impedance sensor 54, 254 at different contact pressures. Fig. 36 depicts a DC amplitude for the impedance sensor 54, 254 at different contact pressures. The AC and DC plots show that at low contact pressures, while the AC amplitude is great, so is the DC amplitude, which gives way to skewed morphological features. The SNR (see Fig. 34) is derived from the AC and DC amplitudes shown in Figs. 35 and 36. The highest contact pressure provides the most consistent pronounced features.

[0144] Knowing the contact pressure that is being applied to the skin surface before analyzing a signal is important as the signal will change as a function of the contact pressure. By looking at the signal acquisition as a function of contact pressure, the system 10, 210, 310 purposely dials into specific contact pressures to look at features that may only be present at that specific contact pressure such that differential analysis may be performed to uncover biomarkers associated with the user.

[0145] Various methods are also provided herein using the system 10, 210, 310. A method of improving physiological signal data output from a biosensor of a wearable biosensing system is provided herein. The method includes providing a case 12, 212, 312, a contact carriage 14, 214, 314 mounted for movement relative to the case 12, 212, 312, the biosensor 16, 216, 316 mounted to the contact carriage 14, 214, 314, and a contact pressure management unit 18, 218, 318. The method includes determining a contact pressure applied to a skin surface of a user by the contact carriage 14, 214, 314 using at least one pressure sensor 22, 222, 322 of the contactpressure management unit 18, 218, 318. The method includes measuring physiological signals of the user using the biosensor 16, 216, 316. The method includes storing contact pressure data and the physiological signal data in a memory 48, 248, 348 of a controller 40, 240, 340 of the contact pressure management unit 18, 218, 318. The method includes associating the contact pressure data with the physiological signal data to manage motion artifacts and other irregularities in the physiological signal data. The method includes generating an instruction associated with an optimized contact pressure based, at least in part, on the contact pressure data received from the at least one pressure sensor 22, 222, 322 and the physiological signal data received from the biosensor 16, 216, 316.

[0146] In some embodiments, the method includes outputting the instruction associated with the optimized contact pressure to a user interface 52, 252, 352. In some embodiments, the method includes communicating the instruction associated with the optimized contact pressure to a carriage driver 20, 220, 320 of the contact pressure management unit 18, 218, 318. In some embodiments, the method includes moving the contact carriage 14, 214, 314 and the biosensor 16, 216, 316 relative to the case 12, 212, 312 via the carriage driver 20, 220, 320 to change the contact pressure applied by the contact carriage 14, 214, 314 to the skin surface of the user in response to receiving the instruction from the controller 40, 240, 340.

[0147] In some embodiments, the at least one pressure sensor 22, 222, 322 is an at least one strain gauge. In some embodiments, the biosensor 16, 216, 316 is provided by the at least one pressure sensor 22, 222, 322. In some embodiments, the biosensor 16, 216 is provided by a photoplethysmogram (PPG) sensor.

[0148] In some embodiments, the carriage driver 20, 220, 320 comprises at least one screw extending through a top wall 24, 224, 324 of the case 12, 212, 312 and into the contact carriage 14, 214, 314. In some embodiments, the method includes rotating the at least one screw to move the contact carriage 14, 214, 314 and the biosensor 16, 216, 316 relative to the case 12, 212, 312. In some embodiments, the contact carriage 14, 214, 314 includes a pressure applicator 34, 234, 334 configured to apply the contact pressure to the skin surface of the user, at least one drive platform 36, 236, 336, and at least one bridge 38, 238, 338 extending between and interconnecting the pressure applicator 34, 234, 334 and the at least one drive platform 36, 236, 336. In some embodiments, the method includes driving the at least one driveplatform 36, 236, 336 via the carriage driver 20, 220, 320 to change the contact pressure applied by the contact carriage 14, 214, 314 to the skin surface of the user.

[0149] In some embodiments, the method includes providing an impedance sensor 54, 254 and storing bioimpedance measurements of the user in the memory 48, 248 of the controller 40, 240. In some embodiments, the method includes moving the contact carriage 14 and the biosensor 16 relative to the case 12 and the impedance sensor 54 to change the contact pressure applied by the contact carriage 14 to the skin surface of the user.

[0150] In some embodiments, the method includes moving the impedance sensor 254 with the contact carriage 214 and the biosensor 216 relative to the case 212 to change the contact pressure applied by the contact carriage 214 to the skin surface of the user. In some embodiments, the method includes adhering the case 12 to the skin surface of the user via a plurality of wet electrodes 58. In some embodiments, the method includes adhering the case 12, 212, 312 to the skin surface of the user via an adhesive material 15, 215, 315.

[0151] The following numbered clauses include embodiments that are contemplated and non-limiting:

[0152] Clause 1 . A wearable biosensing system comprising a case adapted to be fixed to a skin surface of a user, the case including a bottom surface adapted to contact the skin surface of the user and a top wall spaced apart from the bottom surface, a contact carriage mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, a biosensor mounted to the contact carriage for movement therewith relative to the case and configured to measure physiological signals of the user, and a contact pressure management unit including a carriage driver and at least one strain gauge mounted for movement with the contact carriage, the carriage driver configured to move the contact carriage and the biosensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user, and the at least one strain gauge configured to output pressure data suitable for determining the contact pressure developed between the contact carriage and the skin surface of the user so that the contact pressure can be associated with physiological signal data from the biosensor mounted to the contact carriage and can be used as input for adjustments to operation of the carriage driver.

[0153] Clause 2. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by the at least one strain gauge.

[0154] Clause 3. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by a photoplethysmogram (PPG) sensor.

[0155] Clause 4. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by any of the following or any combination of the following: a photoplethysmogram (PPG) sensor, a temperature sensor, an accelerometer, or a gyroscope.

[0156] Clause 5. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver is coupled with the top wall of the case and the contact carriage to selectively move the contact carriage relative to the case to adjust the contact pressure applied to the skin surface of the user by the contact carriage.

[0157] Clause 6. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the contact pressure management unit further includes a controller in communication with the at least one strain gauge, the controller configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver; and wherein the optimized contact pressure is based, at least in part, on the pressure data received from the at least one strain gauge.

[0158] Clause 7. The wearable biosensing system of clause 6, of any one other suitable clause, or any suitable combination of clauses, wherein the controller is in communication with the biosensor; and wherein the instruction associated with the optimized contact pressure is based, at least in part, on the physiological signal data from the biosensor.

[0159] Clause 8. The wearable biosensing system of clause 6, of any one other suitable clause, or any suitable combination of clauses, wherein the controller is in communication with a user interface; and wherein the controller is configured to output the instruction associated with the optimized contact pressure to the user interface sothat the user is informed of the optimized contact pressure to be implemented via the carriage driver by the user.

[0160] Clause 9. The wearable biosensing system of clause 6, of any one other suitable clause, or any suitable combination of clauses, wherein the controller is in communication with the carriage driver; and wherein the controller is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver.

[0161] Clause 10. The wearable biosensing system of clause 9, of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver is configured to move the contact carriage in response to receiving the instruction from the controller so that the contact pressure aligns with the optimized contact pressure.

[0162] Clause 11 . The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver comprises at least one screw extending through the top wall of the case and into the contact carriage; and wherein the at least one screw is configured to rotate to move the contact carriage relative to the case.

[0163] Clause 12. The wearable biosensing system of clause 11 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver comprises at least one motor configured to drive rotation of the at least one screw to cause the contact carriage to move relative to the case.

[0164] Clause 13. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the contact carriage includes a pressure applicator configured to apply the contact pressure to the skin surface of the user, at least one drive platform configured to be driven by the carriage driver, and at least one bridge extending between and interconnecting the pressure applicator and the at least one drive platform.

[0165] Clause 14. The wearable biosensing system of clause 13, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one strain gauge is mounted to the at least one bridge of the contact carriage.

[0166] Clause 15. The wearable biosensing system of clause 13, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one drive platform of the contact carriage includes a first drive platform and a second drive platform spaced apart from one another; and wherein the at least one bridge includesa first bridge and a second bridge, the first bridge extending between and interconnecting the first drive platform and the pressure applicator and the second bridge extending between and interconnecting the pressure applicator and the second drive platform.

[0167] Clause 16. The wearable biosensing system of clause 15, of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver includes a first actuator extending between the top wall of the case and the first drive platform and a second actuator extending between the top wall of the case and the second drive platform; and wherein the first actuator and the second actuator move the first drive platform and the second drive platform, respectively, relative to the case.

[0168] Clause 17. The wearable biosensing system of clause 15, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one strain gauge includes a first strain gauge mounted to the first bridge and a second strain gauge mounted to the second bridge.

[0169] Clause 18. The wearable biosensing system of clause 13, of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is mounted to the pressure applicator to apply at least a portion of the contact pressure to the skin surface of the user.

[0170] Clause 19. The wearable biosensing system of clause 13, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one strain gauge is spaced apart from a bottom surface of the pressure applicator such that the at least one strain gauge is located closer to the top wall of the case than the bottom surface of the pressure applicator.

[0171] Clause 20. The wearable biosensing system of clause 13, of any one other suitable clause, or any suitable combination of clauses, further comprising an impedance sensor configured to output bioimpedance measurements of the user, the impedance sensor including an insulative platform and a plurality of electrodes coupled to a bottom surface of the insulative platform that faces away from the top wall of the case.

[0172] Clause 21 . The wearable biosensing system of clause 20, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one drive platform and the at least one bridge of the contact carriage are located between the top wall of the case and the insulative platform of the impedance sensor.

[0173] Clause 22. The wearable biosensing system of clause 20, of any one other suitable clause, or any suitable combination of clauses, wherein the insulative platform of the impedance sensor is formed to define an applicator-receiving hole that extends entirely vertically through the insulative platform; and wherein the pressure applicator of the contact carriage is positioned to extend through the applicatorreceiving hole.

[0174] Clause 23. The wearable biosensing system of clause 20, of any one other suitable clause, or any suitable combination of clauses, wherein the insulative platform of the impedance sensor is mounted to the case such that the contact carriage moves relative to the case and the impedance sensor.

[0175] Clause 24. The wearable biosensing system of clause 23, of any one other suitable clause, or any suitable combination of clauses, wherein the pressure applicator of the contact carriage is configured to move within the applicator-receiving hole as the contact carriage moves relative to the case and the impedance sensor so that the pressure applicator applies the contact pressure to the skin surface of the user.

[0176] Clause 25. The wearable biosensing system of clause 23, of any one other suitable clause, or any suitable combination of clauses, wherein the plurality of electrodes are wet electrodes; and wherein the wet electrodes provide adhesion of the wearable biosensing system to the skin surface of the user upon placement in contact with the user.

[0177] Clause 26. The wearable biosensing system of clause 20, of any one other suitable clause, or any suitable combination of clauses, wherein the impedance sensor is mounted to the contact carriage such that the impedance sensor moves with the contact carriage relative to the case.

[0178] Clause 27. The wearable biosensing system of clause 26, of any one other suitable clause, or any suitable combination of clauses, wherein the plurality of electrodes of the impedance sensor and the pressure applicator of the contact carriage apply the contact pressure to the skin surface of the user.

[0179] Clause 28. The wearable biosensing system of clause 26, of any one other suitable clause, or any suitable combination of clauses, wherein the plurality of electrodes are dry electrodes.

[0180] Clause 29. The wearable biosensing system of clause 1 , of any one other suitable clause, or any suitable combination of clauses, wherein the case further includes side wall extending downwardly away from the top wall and a flange extending outwardly away from the side wall, the bottom surface of the case being defined on the side wall.

[0181] Clause 30. The wearable biosensing system of clause 29, of any one other suitable clause, or any suitable combination of clauses, wherein the case further includes an adhesive material adhered to the flange of the case and configured to be adhered to the skin surface of the user upon placement in contact with the user.

[0182] Clause 31 . A wearable biosensing system comprising a case adapted to be fixed to a skin surface of a user, the case including a bottom surface adapted to contact the skin surface of the user and a top wall spaced apart from the bottom surface, a contact carriage mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, a biosensor mounted to the contact carriage for movement therewith relative to the case and configured to measure physiological signals of the user, and a contact pressure management unit including a carriage driver and at least one pressure sensor mounted for movement with the contact carriage, the carriage driver configured to move the contact carriage and the biosensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user, and the at least one pressure sensor configured to output pressure data suitable for determining the contact pressure developed between the contact carriage and the skin surface of the user so that the contact pressure can be associated with physiological signal data from the biosensor mounted to the contact carriage and can be used as input for adjustments to operation of the carriage driver.

[0183] Clause 32. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by the at least one pressure sensor.

[0184] Clause 33. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by a photoplethysmogram (PPG) sensor.

[0185] Clause 34. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor isprovided by any of the following or any combination of the following: a photoplethysmogram (PPG) sensor, a temperature sensor, an accelerometer, or a gyroscope.

[0186] Clause 35. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver is coupled with the top wall of the case and the contact carriage to selectively move the contact carriage relative to the case to adjust the contact pressure applied to the skin surface of the user by the contact carriage.

[0187] Clause 36. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the contact pressure management unit further includes a controller in communication with the at least one pressure sensor, the controller configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver; and wherein the optimized contact pressure is based, at least in part, on the pressure data received from the at least one pressure sensor.

[0188] Clause 37. The wearable biosensing system of clause 36, of any one other suitable clause, or any suitable combination of clauses, wherein the controller is in communication with the biosensor; and wherein the instruction associated with the optimized contact pressure is based, at least in part, on the physiological signal data from the biosensor.

[0189] Clause 38. The wearable biosensing system of clause 36, of any one other suitable clause, or any suitable combination of clauses, wherein the controller is in communication with a user interface; and wherein the controller is configured to output the instruction associated with the optimized contact pressure to the user interface so that the user is informed of the optimized contact pressure to be implemented via the carriage driver by the user.

[0190] Clause 39. The wearable biosensing system of clause 36, of any one other suitable clause, or any suitable combination of clauses, wherein the controller is in communication with the carriage driver; and wherein the controller is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver.

[0191] Clause 40. The wearable biosensing system of clause 39, of any one other suitable clause, or any suitable combination of clauses, wherein the carriagedriver is configured to move the contact carriage in response to receiving the instruction from the controller so that the contact pressure aligns with the optimized contact pressure.

[0192] Clause 41 . The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver comprises at least one screw extending through the top wall of the case and into the contact carriage; and wherein the at least one screw is configured to rotate to move the contact carriage relative to the case.

[0193] Clause 42. The wearable biosensing system of clause 41 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver comprises at least one motor configured to drive rotation of the at least one screw to cause the contact carriage to move relative to the case.

[0194] Clause 43. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the contact carriage includes a pressure applicator configured to apply the contact pressure to the skin surface of the user, at least one drive platform configured to be driven by the carriage driver, and at least one bridge extending between and interconnecting the pressure applicator and the at least one drive platform.

[0195] Clause 44. The wearable biosensing system of clause 43, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one pressure sensor is mounted to the at least one bridge of the contact carriage.

[0196] Clause 45. The wearable biosensing system of clause 43, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one drive platform of the contact carriage includes a first drive platform and a second drive platform spaced apart from one another; and wherein the at least one bridge includes a first bridge and a second bridge, the first bridge extending between and interconnecting the first drive platform and the pressure applicator and the second bridge extending between and interconnecting the pressure applicator and the second drive platform.

[0197] Clause 46. The wearable biosensing system of clause 45, of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver includes a first actuator extending between the top wall of the case and the first drive platform and a second actuator extending between the top wall of the case andthe second drive platform; and wherein the first actuator and the second actuator move the first drive platform and the second drive platform, respectively, relative to the case.

[0198] Clause 47. The wearable biosensing system of clause 45, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one pressure sensor includes a first strain gauge mounted to the first bridge and a second strain gauge mounted to the second bridge.

[0199] Clause 48. The wearable biosensing system of clause 43, of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is mounted to the pressure applicator to apply at least a portion of the contact pressure to the skin surface of the user.

[0200] Clause 49. The wearable biosensing system of clause 43, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one pressure sensor is spaced apart from a bottom surface of the pressure applicator such that the at least one pressure sensor is located closer to the top wall of the case than the bottom surface of the pressure applicator.

[0201] Clause 50. The wearable biosensing system of clause 43, of any one other suitable clause, or any suitable combination of clauses, further comprising an impedance sensor configured to output bioimpedance measurements of the user, the impedance sensor including an insulative platform and a plurality of electrodes coupled to a bottom surface of the insulative platform that faces away from the top wall of the case.

[0202] Clause 51 . The wearable biosensing system of clause 50, of any one other suitable clause, or any suitable combination of clauses, wherein the at least one drive platform and the at least one bridge of the contact carriage are located between the top wall of the case and the insulative platform of the impedance sensor.

[0203] Clause 52. The wearable biosensing system of clause 50, of any one other suitable clause, or any suitable combination of clauses, wherein the insulative platform of the impedance sensor is formed to define an applicator-receiving hole that extends entirely vertically through the insulative platform; and wherein the pressure applicator of the contact carriage is positioned to extend through the applicatorreceiving hole.

[0204] Clause 53. The wearable biosensing system of clause 50, of any one other suitable clause, or any suitable combination of clauses, wherein the insulativeplatform of the impedance sensor is mounted to the case such that the contact carriage moves relative to the case and the impedance sensor.

[0205] Clause 54. The wearable biosensing system of clause 53, of any one other suitable clause, or any suitable combination of clauses, wherein the pressure applicator of the contact carriage is configured to move within the applicator-receiving hole as the contact carriage moves relative to the case and the impedance sensor so that the pressure applicator applies the contact pressure to the skin surface of the user.

[0206] Clause 55. The wearable biosensing system of clause 53, of any one other suitable clause, or any suitable combination of clauses, wherein the plurality of electrodes are wet electrodes; and wherein the wet electrodes provide adhesion of the wearable biosensing system to the skin surface of the user upon placement in contact with the user.

[0207] Clause 56. The wearable biosensing system of clause 50, of any one other suitable clause, or any suitable combination of clauses, wherein the impedance sensor is mounted to the contact carriage such that the impedance sensor moves with the contact carriage relative to the case.

[0208] Clause 57. The wearable biosensing system of clause 56, of any one other suitable clause, or any suitable combination of clauses, wherein the plurality of electrodes of the impedance sensor and the pressure applicator of the contact carriage apply the contact pressure to the skin surface of the user.

[0209] Clause 58. The wearable biosensing system of clause 56, of any one other suitable clause, or any suitable combination of clauses, wherein the plurality of electrodes are dry electrodes.

[0210] Clause 59. The wearable biosensing system of clause 31 , of any one other suitable clause, or any suitable combination of clauses, wherein the case further includes side wall extending downwardly away from the top wall and a flange extending outwardly away from the side wall, the bottom surface of the case being defined on the side wall.

[0211] Clause 60. The wearable biosensing system of clause 59, of any one other suitable clause, or any suitable combination of clauses, wherein the case further includes an adhesive material adhered to the flange of the case and configured to be adhered to the skin surface of the user upon placement in contact with the user.

[0212] Clause 61 . A method of improving physiological signal data output from a biosensor of a wearable biosensing system, the method comprising providing a case, a contact carriage mounted for movement relative to the case, the biosensor mounted to the contact carriage, and a contact pressure management unit, determining a contact pressure applied to a skin surface of a user by the contact carriage using at least one pressure sensor of the contact pressure management unit, measuring physiological signals of the user using the biosensor, storing contact pressure data and the physiological signal data in a memory of a controller of the contact pressure management unit, associating the contact pressure data with the physiological signal data to manage motion artifacts and other irregularities in the physiological signal data, and generating an instruction associated with an optimized contact pressure based, at least in part, on the contact pressure data received from the at least one pressure sensor and the physiological signal data received from the biosensor.

[0213] Clause 62. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, further comprising outputting the instruction associated with the optimized contact pressure to a user interface.

[0214] Clause 63. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, further comprising communicating the instruction associated with the optimized contact pressure to a carriage driver of the contact pressure management unit.

[0215] Clause 64. The method of clause 62, of any one other suitable clause, or any suitable combination of clauses, further comprising moving the contact carriage and the biosensor relative to the case via the carriage driver to change the contact pressure applied by the contact carriage to the skin surface of the user in response to receiving the instruction from the controller.

[0216] Clause 65. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, wherein the at least one pressure sensor is an at least one strain gauge.

[0217] Clause 66. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by the at least one pressure sensor.

[0218] Clause 67. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, wherein the biosensor is provided by a photoplethysmogram (PPG) sensor.

[0219] Clause 68. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, wherein the carriage driver comprises at least one screw extending through a top wall of the case and into the contact carriage; and wherein the method further comprises rotating the at least one screw to move the contact carriage and the biosensor relative to the case.

[0220] Clause 69. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, wherein the contact carriage includes a pressure applicator configured to apply the contact pressure to the skin surface of the user, at least one drive platform, and at least one bridge extending between and interconnecting the pressure applicator and the at least one drive platform; and wherein the method further comprises driving the at least one drive platform via the carriage driver to change the contact pressure applied by the contact carriage to the skin surface of the user.

[0221] Clause 70. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, further comprising providing an impedance sensor and storing bioimpedance measurements of the user in the memory of the controller.

[0222] Clause 71 . The method of clause 70, of any one other suitable clause, or any suitable combination of clauses, further comprising moving the contact carriage and the biosensor relative to the case and the impedance sensor to change the contact pressure applied by the contact carriage to the skin surface of the user.

[0223] Clause 72. The method of clause 70, of any one other suitable clause, or any suitable combination of clauses, further comprising moving the impedance sensor with the contact carriage and the biosensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user.

[0224] Clause 73. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, further comprising adhering the case to the skin surface of the user via a plurality of wet electrodes.

[0225] Clause 74. The method of clause 61 , of any one other suitable clause, or any suitable combination of clauses, further comprising adhering the case to the skin surface of the user via an adhesive material.

[0226] While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.

Claims

WHAT IS CLAIMED IS:1 . A wearable biosensing system comprising a case adapted to be fixed to a skin surface of a user, the case including a bottom surface adapted to contact the skin surface of the user and a top wall spaced apart from the bottom surface, a contact carriage mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, a biosensor mounted to the contact carriage for movement therewith relative to the case and configured to measure physiological signals of the user, and a contact pressure management unit including a carriage driver and at least one strain gauge mounted for movement with the contact carriage, the carriage driver configured to move the contact carriage and the biosensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user, and the at least one strain gauge configured to output pressure data suitable for determining the contact pressure developed between the contact carriage and the skin surface of the user so that the contact pressure can be associated with physiological signal data from the biosensor mounted to the contact carriage and can be used as input for adjustments to operation of the carriage driver.

2. The wearable biosensing system of claim 1 , wherein the biosensor is provided by the at least one strain gauge.

3. The wearable biosensing system of claim 1 , wherein the biosensor is provided by a photoplethysmogram (PPG) sensor.

4. The wearable biosensing system of claim 1 , wherein the biosensor is provided by any of the following or any combination of the following: a photoplethysmogram (PPG) sensor, a temperature sensor, an accelerometer, or a gyroscope.

5. The wearable biosensing system of any one of the preceding claims, wherein the carriage driver is coupled with the top wall of the case and the contact carriage to selectively move the contact carriage relative to the case to adjust the contact pressure applied to the skin surface of the user by the contact carriage.

6. The wearable biosensing system of any one of the preceding claims, wherein the contact pressure management unit further includes a controller incommunication with the at least one strain gauge, the controller configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver; and wherein the optimized contact pressure is based, at least in part, on the pressure data received from the at least one strain gauge.

7. The wearable biosensing system of claim 6, wherein the controller is in communication with the biosensor; and wherein the instruction associated with the optimized contact pressure is based, at least in part, on the physiological signal data from the biosensor.

8. The wearable biosensing system of claims 6 or 7, wherein the controller is in communication with a user interface; and wherein the controller is configured to output the instruction associated with the optimized contact pressure to the user interface so that the user is informed of the optimized contact pressure to be implemented via the carriage driver by the user.

9. The wearable biosensing system of claims 6 or 7, wherein the controller is in communication with the carriage driver; and wherein the controller is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver.

10. The wearable biosensing system of claim 9, wherein the carriage driver is configured to move the contact carriage in response to receiving the instruction from the controller so that the contact pressure aligns with the optimized contact pressure.11 . The wearable biosensing system of any one of the preceding claims, wherein the carriage driver comprises at least one screw extending through the top wall of the case and into the contact carriage; and wherein the at least one screw is configured to rotate to move the contact carriage relative to the case.

12. The wearable biosensing system of claim 11 , wherein the carriage driver comprises at least one motor configured to drive rotation of the at least one screw to cause the contact carriage to move relative to the case.

13. The wearable biosensing system of any one of the preceding claims, wherein the contact carriage includes a pressure applicator configured to apply the contact pressure to the skin surface of the user, at least one drive platform configured to be driven by the carriage driver, and at least one bridge extendingbetween and interconnecting the pressure applicator and the at least one drive platform.

14. The wearable biosensing system of claim 13, wherein the at least one strain gauge is mounted to the at least one bridge of the contact carriage.

15. The wearable biosensing system of claim 13, wherein the at least one drive platform of the contact carriage includes a first drive platform and a second drive platform spaced apart from one another; and wherein the at least one bridge includes a first bridge and a second bridge, the first bridge extending between and interconnecting the first drive platform and the pressure applicator and the second bridge extending between and interconnecting the pressure applicator and the second drive platform.

16. The wearable biosensing system of claim 15, wherein the carriage driver includes a first actuator extending between the top wall of the case and the first drive platform and a second actuator extending between the top wall of the case and the second drive platform; and wherein the first actuator and the second actuator move the first drive platform and the second drive platform, respectively, relative to the case.

17. The wearable biosensing system of claims 15 or 16, wherein the at least one strain gauge includes a first strain gauge mounted to the first bridge and a second strain gauge mounted to the second bridge.

18. The wearable biosensing system of any of claims 13-17, wherein the biosensor is mounted to the pressure applicator to apply at least a portion of the contact pressure to the skin surface of the user.

19. The wearable biosensing system of any of claims 13-17, wherein the at least one strain gauge is spaced apart from a bottom surface of the pressure applicator such that the at least one strain gauge is located closer to the top wall of the case than the bottom surface of the pressure applicator.

20. The wearable biosensing system of any of claims 13-19, further comprising an impedance sensor configured to output bioimpedance measurements of the user, the impedance sensor including an insulative platform and a plurality of electrodes coupled to a bottom surface of the insulative platform that faces away from the top wall of the case.21 . The wearable biosensing system of claim 20, wherein the at least one drive platform and the at least one bridge of the contact carriage are located between the top wall of the case and the insulative platform of the impedance sensor.

22. The wearable biosensing system of claims 20 or 21 , wherein the insulative platform of the impedance sensor is formed to define an applicator-receiving hole that extends entirely vertically through the insulative platform; and wherein the pressure applicator of the contact carriage is positioned to extend through the applicator-receiving hole.

23. The wearable biosensing system of any of claims 20-22, wherein the insulative platform of the impedance sensor is mounted to the case such that the contact carriage moves relative to the case and the impedance sensor.

24. The wearable biosensing system of claim 23, wherein the pressure applicator of the contact carriage is configured to move within the applicatorreceiving hole as the contact carriage moves relative to the case and the impedance sensor so that the pressure applicator applies the contact pressure to the skin surface of the user.

25. The wearable biosensing system of claims 23 or 24, wherein the plurality of electrodes are wet electrodes; and wherein the wet electrodes provide adhesion of the wearable biosensing system to the skin surface of the user upon placement in contact with the user.

26. The wearable biosensing system of any of claims 20-22, wherein the impedance sensor is mounted to the contact carriage such that the impedance sensor moves with the contact carriage relative to the case.

27. The wearable biosensing system of claim 26, wherein the plurality of electrodes of the impedance sensor and the pressure applicator of the contact carriage apply the contact pressure to the skin surface of the user.

28. The wearable biosensing system of claim 26 or 27, wherein the plurality of electrodes are dry electrodes.

29. The wearable biosensing system of any preceding claim, wherein the case further includes side wall extending downwardly away from the top wall and a flange extending outwardly away from the side wall, the bottom surface of the case being defined on the side wall.

30. The wearable biosensing system of claim 29, wherein the case further includes an adhesive material adhered to the flange of the case and configured to be adhered to the skin surface of the user upon placement in contact with the user.31 . A wearable biosensing system comprising a case adapted to be fixed to a skin surface of a user, the case including a bottom surface adapted to contact the skin surface of the user and a top wall spaced apart from the bottom surface, a contact carriage mounted for movement relative to the case into contact with the skin surface of the user to apply a contact pressure to the skin surface of the user, a biosensor mounted to the contact carriage for movement therewith relative to the case and configured to measure physiological signals of the user, and a contact pressure management unit including a carriage driver and at least one pressure sensor mounted for movement with the contact carriage, the carriage driver configured to move the contact carriage and the biosensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user, and the at least one pressure sensor configured to output pressure data suitable for determining the contact pressure developed between the contact carriage and the skin surface of the user so that the contact pressure can be associated with physiological signal data from the biosensor mounted to the contact carriage and can be used as input for adjustments to operation of the carriage driver.

32. The wearable biosensing system of claim 31 , wherein the biosensor is provided by the at least one pressure sensor.

33. The wearable biosensing system of claim 31 , wherein the biosensor is provided by a photoplethysmogram (PPG) sensor.

34. The wearable biosensing system of claim 31 , wherein the biosensor is provided by any of the following or any combination of the following: a photoplethysmogram (PPG) sensor, a temperature sensor, an accelerometer, or a gyroscope.

35. The wearable biosensing system of any of claims 31 -34, wherein the carriage driver is coupled with the top wall of the case and the contact carriage to selectively move the contact carriage relative to the case to adjust the contact pressure applied to the skin surface of the user by the contact carriage.

36. The wearable biosensing system of any of claims 31-35, wherein the contact pressure management unit further includes a controller in communication with the at least one pressure sensor, the controller configured to output an instruction associated with an optimized contact pressure to be implemented via adjustment of the carriage driver; and wherein the optimized contact pressure is based, at least in part, on the pressure data received from the at least one pressure sensor.

37. The wearable biosensing system of claim 36, wherein the controller is in communication with the biosensor; and wherein the instruction associated with the optimized contact pressure is based, at least in part, on the physiological signal data from the biosensor.

38. The wearable biosensing system of claims 36 or 37, wherein the controller is in communication with a user interface; and wherein the controller is configured to output the instruction associated with the optimized contact pressure to the user interface so that the user is informed of the optimized contact pressure to be implemented via the carriage driver by the user.

39. The wearable biosensing system of claims 36 or 37, wherein the controller is in communication with the carriage driver; and wherein the controller is configured to communicate the instruction associated with the optimized contact pressure to the carriage driver.

40. The wearable biosensing system of claim 39, wherein the carriage driver is configured to move the contact carriage in response to receiving the instruction from the controller so that the contact pressure aligns with the optimized contact pressure.41 . The wearable biosensing system of any of claims 31-40, wherein the carriage driver comprises at least one screw extending through the top wall of the case and into the contact carriage; and wherein the at least one screw is configured to rotate to move the contact carriage relative to the case.

42. The wearable biosensing system of claim 41 , wherein the carriage driver comprises at least one motor configured to drive rotation of the at least one screw to cause the contact carriage to move relative to the case.

43. The wearable biosensing system of any of claims 31-42, wherein the contact carriage includes a pressure applicator configured to apply the contact pressure to the skin surface of the user, at least one drive platform configured to bedriven by the carriage driver, and at least one bridge extending between and interconnecting the pressure applicator and the at least one drive platform.

44. The wearable biosensing system of claim 43, wherein the at least one pressure sensor is mounted to the at least one bridge of the contact carriage.

45. The wearable biosensing system of claim 43, wherein the at least one drive platform of the contact carriage includes a first drive platform and a second drive platform spaced apart from one another; and wherein the at least one bridge includes a first bridge and a second bridge, the first bridge extending between and interconnecting the first drive platform and the pressure applicator and the second bridge extending between and interconnecting the pressure applicator and the second drive platform.

46. The wearable biosensing system of claim 45, wherein the carriage driver includes a first actuator extending between the top wall of the case and the first drive platform and a second actuator extending between the top wall of the case and the second drive platform; and wherein the first actuator and the second actuator move the first drive platform and the second drive platform, respectively, relative to the case.

47. The wearable biosensing system of claims 45 or 46, wherein the at least one pressure sensor includes a first strain gauge mounted to the first bridge and a second strain gauge mounted to the second bridge.

48. The wearable biosensing system of any of claims 43-47, wherein the biosensor is mounted to the pressure applicator to apply at least a portion of the contact pressure to the skin surface of the user.

49. The wearable biosensing system of any of claims 43-47, wherein the at least one pressure sensor is spaced apart from a bottom surface of the pressure applicator such that the at least one pressure sensor is located closer to the top wall of the case than the bottom surface of the pressure applicator.

50. The wearable biosensing system of any of claims 43-49, further comprising an impedance sensor configured to output bioimpedance measurements of the user, the impedance sensor including an insulative platform and a plurality of electrodes coupled to a bottom surface of the insulative platform that faces away from the top wall of the case.51 . The wearable biosensing system of claim 50, wherein the at least one drive platform and the at least one bridge of the contact carriage are located between the top wall of the case and the insulative platform of the impedance sensor.

52. The wearable biosensing system of claims 50 or 51 , wherein the insulative platform of the impedance sensor is formed to define an applicator-receiving hole that extends entirely vertically through the insulative platform; and wherein the pressure applicator of the contact carriage is positioned to extend through the applicator-receiving hole.

53. The wearable biosensing system of any of claims 50-52, wherein the insulative platform of the impedance sensor is mounted to the case such that the contact carriage moves relative to the case and the impedance sensor.

54. The wearable biosensing system of claim 53, wherein the pressure applicator of the contact carriage is configured to move within the applicatorreceiving hole as the contact carriage moves relative to the case and the impedance sensor so that the pressure applicator applies the contact pressure to the skin surface of the user.

55. The wearable biosensing system of claims 53 or 54, wherein the plurality of electrodes are wet electrodes; and wherein the wet electrodes provide adhesion of the wearable biosensing system to the skin surface of the user upon placement in contact with the user.

56. The wearable biosensing system of any of claims 50-52, wherein the impedance sensor is mounted to the contact carriage such that the impedance sensor moves with the contact carriage relative to the case.

57. The wearable biosensing system of claim 56, wherein the plurality of electrodes of the impedance sensor and the pressure applicator of the contact carriage apply the contact pressure to the skin surface of the user.

58. The wearable biosensing system of claim 56 or 57, wherein the plurality of electrodes are dry electrodes.

59. The wearable biosensing system of any preceding claim, wherein the case further includes side wall extending downwardly away from the top wall and a flange extending outwardly away from the side wall, the bottom surface of the case being defined on the side wall.

60. The wearable biosensing system of claim 59, wherein the case further includes an adhesive material adhered to the flange of the case and configured to be adhered to the skin surface of the user upon placement in contact with the user.61 . A method of improving physiological signal data output from a biosensor of a wearable biosensing system, the method comprising providing a case, a contact carriage mounted for movement relative to the case, the biosensor mounted to the contact carriage, and a contact pressure management unit, determining a contact pressure applied to a skin surface of a user by the contact carriage using at least one pressure sensor of the contact pressure management unit, measuring physiological signals of the user using the biosensor, storing contact pressure data and the physiological signal data in a memory of a controller of the contact pressure management unit, associating the contact pressure data with the physiological signal data to manage motion artifacts and other irregularities in the physiological signal data, and generating an instruction associated with an optimized contact pressure based, at least in part, on the contact pressure data received from the at least one pressure sensor and the physiological signal data received from the biosensor.

62. The method of claim 61 , further comprising outputting the instruction associated with the optimized contact pressure to a user interface.

63. The method of claim 61 , further comprising communicating the instruction associated with the optimized contact pressure to a carriage driver of the contact pressure management unit.

64. The method of claim 62 or 63, further comprising moving the contact carriage and the biosensor relative to the case via the carriage driver to change the contact pressure applied by the contact carriage to the skin surface of the user in response to receiving the instruction from the controller.

65. The method of any of claims 61-64, wherein the at least one pressure sensor is an at least one strain gauge.

66. The method of any of claims 61-65, wherein the biosensor is provided by the at least one pressure sensor.

67. The method of any of claims 61 -65, wherein the biosensor is provided by a photoplethysmogram (PPG) sensor.

68. The method of any of claims 61-67, wherein the carriage driver comprises at least one screw extending through a top wall of the case and into the contact carriage; and wherein the method further comprises rotating the at least one screw to move the contact carriage and the biosensor relative to the case.

69. The method of any of claims 61 -68, wherein the contact carriage includes a pressure applicator configured to apply the contact pressure to the skin surface of the user, at least one drive platform, and at least one bridge extending between and interconnecting the pressure applicator and the at least one drive platform; and wherein the method further comprises driving the at least one drive platform via the carriage driver to change the contact pressure applied by the contact carriage to the skin surface of the user.

70. The method of any of claims 61-69, further comprising providing an impedance sensor and storing bioimpedance measurements of the user in the memory of the controller.71 . The method of claim 70, further comprising moving the contact carriage and the biosensor relative to the case and the impedance sensor to change the contact pressure applied by the contact carriage to the skin surface of the user.

72. The method of claim 70, further comprising moving the impedance sensor with the contact carriage and the biosensor relative to the case to change the contact pressure applied by the contact carriage to the skin surface of the user.

73. The method of any of claims 61 -72, further comprising adhering the case to the skin surface of the user via a plurality of wet electrodes.

74. The method of any of claims 61 -72, further comprising adhering the case to the skin surface of the user via an adhesive material.

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