The present invention generally relates, in certain aspects, to relatively small devices applied to the skin, modular systems, and methods of use thereof. In some aspects, the device is constructed and arranged to have more than one module. For instance, the device may have a module for delivering to and/or withdrawing fluid from the skin and/or beneath the skin of a subject and a module for transmitting a signal indicative of the fluid delivered to and/or withdrawn from the skin and/or beneath the skin of the subject, a module for analyzing a fluid withdrawn from the skin and/or beneath the skin of the subject, or the like. In some embodiments, the modules are connectable and/or detachable from each other, and in some cases, the connections and/or detachments may be performed while the device is in contact with the subject, e.g., while affixed to the subject. In some embodiments, the device may be repeatedly applicable to the skin of the subject to deliver to and/or withdraw fluid from the skin and/or beneath the skin of a subject, e.g., at the same location, or at different locations on the skin of the subject. In some aspects, the devices may be self-contained and/or have a relatively small size, and in some cases, the device may be sized such that it is wearable and/or able to be carried by a subject. For example, the device may have a mass and/or dimensions that allow the device to be carried or worn by a subject for various periods of time, e.g., at least about an hour, at least about a day, at least about a week, etc., or no more than about an hour, no more than about 10 min, etc.

The present invention generally relates to systems and methods for delivering and/or withdrawing a substance or substances such as blood or interstitial fluid, from subjects, e.g., from the skin and/or from beneath the skin. In one aspect, the present invention is generally directed to devices and methods for withdrawing or extracting blood from a subject, e.g., from the skin and/or from beneath the skin, using devices containing a fluid transporter (for example, one or more microneedles), and a storage chamber having an internal pressure less than atmospheric pressure prior to receiving blood. In some cases, the device may be self-contained, and in certain instances, the device can be applied to the skin, and activated to withdraw blood from the subject. The device, in some cases, may be interfaced with external equipment to determine an analyte contained within a fluid contained within or collected by the device. For example, the device may be mounted or engaged on an external holder, the device may include a port for transporting fluid out of the device, the device may include a window for interrogating a fluid contained within the device, or the like. The device, or a portion thereof, may then be processed to determine the blood and/or an analyte within the blood, alone or with an external apparatus. For example, blood may be withdrawn from the device, and/or the device may contain sensors or agents able to determine the blood and/or an analyte suspected of being contained in the blood. Other aspects of the present invention are directed at other devices for withdrawing blood (or other bodily fluids, e.g., interstitial fluid), kits involving such devices, methods of making such devices, methods of using such devices, and the like.

The present invention generally relates to systems and methods for delivering and/or withdrawing a substance or substances such as blood or interstitial fluid, from subjects, e.g., from the skin and/or from beneath the skin. In one aspect, the present invention is generally directed to devices and methods for withdrawing or extracting blood from a subject, e.g., from the skin and/or from beneath the skin, using devices containing a fluid transporter (for example, one or more microneedles), and a storage chamber having an internal pressure less than atmospheric pressure prior to receiving blood. In some cases, the device may be self-contained, and in certain instances, the device can be applied to the skin, and activated to withdraw blood from the subject. The device, or a portion thereof, may then be processed to determine the blood and/or an analyte within the blood, alone or with an external apparatus. For example, blood may be withdrawn from the device, and/or the device may contain sensors or agents able to determine the blood and/or an analyte suspected of being contained in the blood. Other aspects of the present invention are directed at other devices for withdrawing blood (or other bodily fluids, e.g., interstitial fluid), kits involving such devices, methods of making such devices, methods of using such devices, and the like.

The disclosed apparatus, systems and methods relate to the collection of bodily fluids through the use of gravity and microfluidic properties by way of a collector. The collector can make use of microfluidic networks connected to collection sites on the skin of a subject to gather and shuttle blood into a reservoir by a combination of capillary action and gravitational forces. The collected fluid is moved through the microfluidic networks and into the reservoir by a variety of approaches.

The present invention generally relates to systems and methods for delivering and/or withdrawing a substance or substances such as blood or interstitial fluid, from subjects, e.g., from the skin and/or from beneath the skin. In one aspect, the present invention is generally directed to devices and methods for withdrawing or extracting blood from a subject, e.g., from the skin and/or from beneath the skin, using devices containing a fluid transporter (for example, one or more microneedles), and a storage chamber having an internal pressure less than atmospheric pressure prior to receiving blood. In some cases, the device may be self-contained, and in certain instances, the device can be applied to the skin, and activated to withdraw blood from the subject. The device, or a portion thereof, may then be processed to determine the blood and/or an analyte within the blood, alone or with an external apparatus. For example, blood may be withdrawn from the device, and/or the device may contain sensors or agents able to determine the blood and/or an analyte suspected of being contained in the blood. Other aspects of the present invention are directed at other devices for withdrawing blood (or other bodily fluids, e.g., interstitial fluid), kits involving such devices, methods of making such devices, methods of using such devices, and the like.

In some embodiments, a wearable patch can include a patch structure having one or more layers and configured to allow the patch to be worn by a user. The patch can further include an assay component implemented on or at least partially within the patch structure, and configured to obtain a blood sample of the user and perform an assay on the blood sample. The patch can further include a flow assembly having one or more input needles in communication with the assay component and one or more output needles in communication with the assay component to provide a continuous flow of blood for the assay component to thereby allow the blood sample to be obtained by the assay component. Each of the one or more input needles and one or more output needles can be configured to interface with a respective capillary in a tissue of the user.

Disclosed herein are devices, apparatus, systems, methods and kits for collecting and storing a fluid sample from a subject. A device for collecting the fluid sample can include a housing comprising a recess having an opening, a vacuum chamber in the housing and in fluidic communication with the recess, and one or more piercing elements that are extendable through the opening to penetrate skin of the subject. The vacuum chamber can be configured for having a vacuum that draws the skin into the recess. The recess can be configured having a size or shape that enables an increased volume of the fluid sample to be accumulated in the skin drawn into the recess.

The present invention generally relates to receiving bodily fluid through a device opening. In one aspect, the device includes a flow activator arranged to cause fluid to be released from a subject. A deployment actuator may actuate the flow activator in a deployment direction, which may in turn cause fluid release from a subject. The flow activator may also be moved in a retraction direction by a retraction actuator. In one aspect, the device may include a vacuum source that may help facilitate fluid flow into the opening of the device and/or may help facilitate fluid flow from the opening to a storage chamber. In one aspect, a device actuator may enable fluid communication between the opening and the vacuum source and the flow activator may be actuated after the enablement of fluid communication.

The present invention generally relates to receiving bodily fluid through a device opening. In one aspect, the device includes a flow activator arranged to cause fluid to be released from a subject. A deployment actuator may actuate the flow activator in a deployment direction, which may in turn cause fluid release from a subject. The flow activator may also be moved in a retraction direction by a retraction actuator. In one aspect, the device may include a vacuum source that may help facilitate fluid flow into the opening of the device and/or may help facilitate fluid flow from the opening to a storage chamber. In one aspect, a device actuator may enable fluid communication between the opening and the vacuum source and the flow activator may be actuated after the enablement of fluid communication.