Phototherapeutic systems including spreading and collimating features and related technology

A phototherapeutic system, comprising:

• a housing at least partially defining an irradiation zone, wherein the irradiation zone is configured to accommodate at least a torso of a human subject;
• a first ultraviolet (UV) radiation assembly including—
• a first UV radiation source configured to direct UV radiation in a forward direction along a first radiation path extending from the first radiation source to the irradiation zone, the first UV radiation source including—
• a first concentrated source at which the UV radiation is generated, and
• a first collimating lens positioned downstream of the first concentrated source to increase collimation of the UV radiation generated at the first concentrated source, the first collimating lens positioned between the radiation source and the irradiation zone, wherein the UV radiation passes through the first collimating lens along a radiation path extending from the first concentrated source downstream to a skin surface of the human subject within the irradiation zone,
• a first spreader disposed along the first radiation path downstream from the first radiation source, and
• a first collimator disposed along the first radiation path downstream from the first spreader to collimate the UV radiation across a first portion of the irradiation zone and deliver the UV radiation with a high degree of uniformity across the first portion of the irradiation zone;
• and
• a second ultraviolet (UV) radiation assembly including—
• a second UV radiation source configured to direct UV radiation in a forward direction along a second radiation path extending from the second radiation source to the irradiation zone, the second radiation assembly includes—
• a second concentrated source at which UV radiation is generated, and
• a second collimating lens positioned downstream of the second concentrated source to increase collimation of the UV radiation generated at the second concentrated source, the second collimating lens positioned between the radiation source and the irradiation zone, wherein the UV radiation passes through the second collimating lens along the radiation path extending from the second concentrated source downstream to the skin surface of the human subject within the irradiation zone,
• a second spreader disposed along the second radiation path downstream from the second radiation source, and
• a second collimator disposed along the second radiation path downstream from the second spreader to collimate the UV radiation across a second portion of the irradiation zone and deliver the UV radiation with a high degree of uniformity across the second portion of the irradiation zone,
• wherein, when the torso is within the first and second portions of the irradiation zone, the first and second collimators are configured to expose a skin surface of the torso to highly uniform collimated UV radiation across the torso independent of a distance between the UV radiation source and the torso.

A phototherapeutic method, comprising:

• generating UV radiation at a concentrated source, wherein the UV radiation is directed in a forward direction toward an irradiation zone;
• refracting the UV radiation generated at the concentrated source with a collimating lens positioned downstream of the concentrated source to increase collimation of the UV radiation generated at the concentrated source, wherein the collimating lens is positioned between the concentrated source and the irradiation zone, wherein the UV radiation passes through the collimating lens along a radiation path extending from the concentrated source downstream to a skin surface of a human subject, the skin surface corresponding to at least a torso within the irradiation zone;
• filtering the UV radiation after collimation;
• spreading the filtered UV radiation;
• and
• increasing collimation of spread UV radiation to collimate the UV radiation across the irradiation zone and deliver the UV radiation with a high degree of uniformity across the irradiation zone,
• wherein, when the torso is within the irradiation zone, the collimation exposes a skin surface of the torso to highly uniform collimated UV radiation across the torso independent of a distance between the concentrated source and the torso.