THE RIGHT LIGHT AT THE RIGHT TIME FOR BIPOLAR PATIENTS - DIVA
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DEGREE PROJECT IN ARCHITECTURE, SECOND CYCLE, 15 CREDITS STOCKHOLM, SWEDEN 2021 The Right Light at the Right Time for Bipolar Patients An exploratory study of light environments for patients with bipolar disease in behavioral health clinics MIRA SVANBERG KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ARCHITECTURE AND THE BUILT ENVIRONMENT
TRITA TRITA-ABE-MBT-21138 www.kth.se
Title The Right Light at the Right Time for Bipolar Patients An exploratory study of light environments for patients with bipolar disease in behavioral health clinics Author Mira Svanberg Tutor Arne Lowden KTH School of Architecture - Architectural Lighting Design Course code AF270X Examiner Dr. Ute Besenecker Year 2021 TRITA-ABE-MBT-21138
KTH, 2021
Architectural lighting design
Mira Svanberg
The Right Light at the Right Time for
Bipolar Patients
An exploratory study of light environments for patients
with bipolar disease in behavioral health clinics
Author Mira Svanberg
Tutor Arne Lowden
Year: 2021
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Contents 7.4 Measurements ...................................... 18
1. Abstract......................................................... 4 7.5 Evaluation of patient rooms .............. 20
2. Introduction and objective of thesis .... 5 8. Improved design for patient rooms ... 20
3. Background ................................................. 5 8.1 Light intensity and direction of color
3.1 Bipolar disorder ....................................... 6 ........................................................................... 21
3.2 Circadian system..................................... 6 8.2 Suggested luminaires ......................... 23
3.3 V/P- theory ............................................... 7 8.3 Light program ........................................ 28
4. Method.......................................................... 7 8.4 The improved patient room design
visualized........................................................ 35
5. Results of literature review ..................... 8
9. Discussion................................................. 36
5.1 The biological effect of light ................ 8
9.1 Delimitations .......................................... 36
5.2 Light and bipolar disorder .................... 8
9.2 The improved design .......................... 36
5.3 Depressive episodes .............................. 9
9.3 Sun-like design ..................................... 37
5.4 Manic episodes ................................. 9
10.4 Light program ..................................... 37
5.5 Behavior health light design ................ 9
9.5 Depression ............................................. 38
6. Standards and Recommendations ....10
9.6 Manic state light effects .................... 39
6.1 Patient rooms recommendation from
Lighting guide 2: Lighting for healthcare 9.7 Luminaires in the field study and the
premises..........................................................10 TLM ................................................................. 39
6.2 Manchester Recommendations .......11 10. Conclusion ............................................ 40
6.3 Temporal Light Modulation ...............11 11. Further development......................... 41
7. Field study .................................................13 12. Bibliography .............................................. 41
7.1 Patient room 1 .......................................13 13. Appendix ............................................... 45
7.2 Patient room 2 .......................................15
7.3 V/P-theory of the light situation in
both patient rooms ......................................17
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1. Abstract
Research has showed that different light scenarios have a profound effect on hospitalized bipolar
patients. Different light situations decrease the hospital stay for patients during both manic and
depressive episodes. Nevertheless, a field study carried out during this thesis work of two arbitrary
patient rooms in Swedish behavioral health clinics showed no incorporation of this knowledge in
the light design of the rooms. Both patient rooms had insufficient light levels both in terms of
circadian recommendations and perceived brightness. Hence this thesis suggests an improved light
design for patient rooms housing bipolar patients. The basis of the improved design is to
incorporate a dynamic, circadian lighting that varies depending on the patient's need and diagnosed
episode.
CIE International Commission on Illumination
CRI Color Render Index
IEEEE Institute of Electrical and Electronics Engineers
ipRGC Intrinsically photosensitive Retinal Ganglion Cell
K Kelvin
M-EDI Melanopic Equivalent Daylight Illuminance
SPD Spectral Power Distribution
TLA Temporal Light Artifact
TLM Temporal Light Modulation
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2. Introduction and objective of thesis
The purpose of a behavioral health clinic with compulsory care is to heal and protect. Hence, the
light design for such a premise should support that purpose. Unfortunately, many hospitals provide
stressful environments for their occupants, contradicting their healing intent (Andrade & Devlin,
2021). Patients who are suffering from bipolar disorder, a severe mental disease which afflict 1-4%
of the world population (Geoffroy et al., 2016), is one group which occupies behavioral health
clinics.
The number of Swedish hospitalized bipolar patients has increased rapidly since 1998
(Socialstyrelsen, 2020). This increase motivates the objective of the thesis, which is to investigate
how light design can be implemented to possibly improve the well-being of hospitalized bipolar
patients. The long, dark winter season in Sweden results in a dependency on artificial light.
Therefore, the focus will be only on the impact of this ubiquitous artificial light.
3. Background
Florence Nightingale stated already in 1860
"Without going into any scientific exposition, we must admit that light has quite as real and tangible
effects upon the human body."
(Nightingale, 2005)
Light has been clinically applied as a form of therapy worldwide since the 1980s (Brainard, 2021). It
has been in use as a treatment for seasonal affective disorder, non-seasonal affective disorder, and
in many other health care areas (Lucas et al. 2014). Trials of dynamic circadian light in geriatric
care facilities are relatively common (Chromaviso, 2021). Several research projects in Scandinavia
have conducted pilot studies incorporating circadian light design in psychiatric clinics, with positive
results, such as shortened hospital stays (Chromaviso, 2021).
Although there is ongoing work in the field, the Swedish Agency for Health Technology Assessment
and Assessment of Social Services concluded in 2007 that the evidence value of light therapy was
insufficient (SBU, 2007). They did not entirely reject it but asked for more proper evidence-based
research. As a result of this, the use of light therapy decreased, and in 2015 only seven of 21
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regions used light as a therapeutic tool (SR, 2015). Could the increasing knowledge of the biological
impact of light perhaps provide a second chance for light as part of therapy for bipolar patients?
3.1 Bipolar disorder
Bipolar disease is a severe brain disorder with a palpable risk of suicide, as evident by the 34%
prevalence of suicidal attempts during a patient’s lifetime (American Psychiatric Association, 2021).
It is defined by a depressive, low mood state and an elevated mood state, mania (Gold & Sylvia,
2016). There are three different subclasses of bipolar disorder, but the sleep disturbances are
common for all of them; hence bipolar will be referred to as one disease in this thesis. The
diagnosis of bipolar disorder 1, based on the DSM 5-criteria for depression, partly includes: intense
sadness or despair, frequent thoughts of death or suicide, feelings of worthlessness or guilt,
fatigue, increased or decreased sleep, insomnia, or hypersomnia (American Psychiatric Association,
2021). For manic episodes, DSM-5 criteria include increased or faster speech, Decreased need for
sleep (e.g., feeling energetic despite significantly less sleep than usual), uncontrollable racing
thoughts or quickly changing ideas or topics when speaking, distractibility, and increased activity
and risky behavior (American Psychiatric Association, 2021). As shown by the criteria in bold, sleep
disturbances occur in all stages of bipolar disease in the shape of hypersomnia, insomnia, or
experienced decreased need for sleep. 25% of patients experience hypersomnia or insomnia in an
episode (Kaplan, 2020). Also, in inter-episodes, there seems to be a dysfunction in sleep-wake
time (Bradley et al., 2017).
Sleep is crucial for the healing and recovery of the body in all humans and impacts several factors,
such as immune function, hormone production and motivation, attention, and emotional reactivity
(Aulsebrook, Jones, & et al., 2019). Sleep deprivation is harmful by its negative impact on learning
and memory capacity (Aulsebrook, Jones, & et al., 2019). Some hypotheses even suggest sleep
disturbances to be the root of the bipolar disease (Gold & Sylvia, 2016).
3.2 Circadian system
Human beings have evolved under Earth’s celestial environment, where the movement of the sun
affects our behavior. Today, even though most people inhabit electrified houses, the body is still
somewhat in synch with its ancestral rhythms (Brainard, 2021). The repetitive patterns of behavior
are in a cycle of approximately (circa) 24.2 hours per day (dias) hence the name Circadian rhythm
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(Boyce, 2014). Together with external cues, it affects the body temperature, mood, hunger,
hormone secretion, and the sleep-wake cycle (Gold & Sylvia, 2016). It is regulated by different
external factors, zeitgebers, such as eating habits, exercise, social activities but the most substantial
impact on the circadian system is light (Boyce, 2014). Circadian system, partly governed by light,
communicates when in the day-night cycle sleep should occur, and directly affects the sleep onset
(LeGates, 2014).
3.3 V/P- theory
The visually-and physically-theory V/P-theory was established by the lighting department at the
Swedish, Royal Institute of Technology (KTH). The method aims to depict a space through seven
factors defined as the fundamentals of a light experience (Liljefors, 1999).
4. Method
As a tool for understanding the correlations between the diagnostic criteria for bipolar patients and
light and sleep relations, a literature review was performed.
Keywords
Circadian Light, Light affecting bipolar disorder, Behaviour health clinic design, Circadian light
recommendations. The search was performed on Google scholar and DiVa. The search results
were focused upon the most recent articles but without specified year limits.
Field study
Two arbitrary patient rooms in closed psychiatric clinics in Stockholm and Västervik (p1 and p2),
were evaluated on the qualities of artificial light. The assessment tools in the patient rooms were
both qualitative and quantitative. Qualitatively the rooms were zoned and described by dimensions,
luminaires, materials, and color, affecting the light situation. The V/P-theory was being used and
answered by the author. Quantitatively, photometric and radiometric data were measured with the
GL Optics Spectis spectrometer. The field study of p1 was performed after sunset, with no effect
from natural light. The field study of p2 was conducted during a cloudy afternoon, with the blinds
closed. During the measurements, the natural light was first measured then subtracted from the
artificial illumination levels. The present situation was evaluated and compared to research and
recommendations from the literature review. Suggested improvements to the patient rooms were
made based on the combined results from all evaluations.
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5. Results of literature review
5.1 The biological effect of light
A significant concern for the sleep- and wake rhythms is the impact of the hormones melatonin and
cortisol (Van Bommel, 2019). The brain’s internal clock, the suprachiasmatic nucleus (SCN),
communicates with the pineal gland to produce melatonin and with the adrenal cortex to produce
the energy regulating hormone cortisol (Van Bommel, 2019).
The SCN gets inputs from the intrinsically photosensitive retinal ganglion cells (ipRGCs), which
produce the pigment melanopsin that reacts upon irradiance. Unlike the other photoreceptors, the
rods and cones, ipRGC does not signal any visual input to the brain, but there is communication
from the visual system to the biological system, i.e., from the rods and cones to the ipRGCs
(Brainard, 2021). All photoreceptors have specific spectral sensitivity; even the three-cone types
react differently to different radiation, resulting in trichromatic vision (Van Bommel, 2019). The
combined cone photoreceptors have a peak sensitivity in white light luminance photopic vision at
555 nm, seen as green/yellow. 480 nm is the peak sensitivity for ipRGC, experienced as blue. The
ipRGC’s are not as sensitive to light as the other photoreceptors, thus more sensitive the longer
exposed to light (LeGates, 2014). The higher light intensities, the shorter time for the ipRGCs to
react (Lucas et al., 2013).
Besides wavelengths, light history is a factor that impacts the ipRGC (CIE, 2019). Light history
means that if the circadian system is exposed to constant bright light, it can adapt to maintain
circadian entrainment. Directionality of the light source and whereupon the retina light exposure
appears also impact the melatonin suppression. Light from below does not have as big an impact
on the melatonin suppression as light from above (IES, 2018).
5.2 Light and bipolar disorder
Sleep disturbances are closely linked to bipolar disease, and sleep and wake cycles are partially
governed by light. Research find that bipolar patients have major disturbances in circadian rhythms,
shown, e.g., in low melatonin secretion, both in and between episodes (Geoffroy, Etain, & et al.,
2016) (Bradley et al., 2017).
ipRGC’s influences the circadian rhythm, including sleep pattern, but some studies indicate that it
also directly impacts mood and cognitive functions (LeGates, 2014). The direct impact has been
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noted in studies with rodents, where they have shown anti-depressive behavior when exposed to
aberrant light without affecting the circadian rhythm (LeGates, 2014).
5.3 Depressive episodes
High illuminance from natural light in the morning has been shown to positively affect bipolar
patients in a depressive state. One study concludes a 2.6-day reduction in hospitalization for
patients in rooms with morning light exposure compared to patients in rooms without morning
sunlight (Kathleen Beauchemin & Hays, 1996). Similar results have been shown in a study
comparing bipolar depression patients with unipolar depression. Compared to unipolar depressive
patients, bipolar depressive patients reduced their hospital stay by 3.67 days when exposed to
morning sunlight (Benedetti, Colombo, & et al., 2001).
5.4 Manic episodes
Bipolar Disorders journal published an article in 2017 about a Norwegian case study showing that
when a patient wore blue-blocking glasses, it expedited recovery remarkably and increased the
patient's sleep time (Henriksen, Skrede, & al, 2016). Based on this result, the article discusses the
lack of stimuli to the ipRGC’s which stabilizes the sleep-wake cycle. In other studies, the use of
blue-blocking glasses has been known to stabilize mood without affecting sleep (Kaplan, 2020).
Another form of therapy for manic state patients is dark therapy (Easaki, Objayashi, & et al., 2020).
Pilot studies of dark therapy with 14 hours of exposure to darkness have implied a decrease in
mania (Easaki, Objayashi, & et al., 2020). Easaki’s approach requires 14 hours of complete
darkness.
5.5 Behavior health light design
The average time spent in episodes from the onset of the bipolar disease is 20% (Kaplan, 2020).
Hence the amount of time spent in a clinic is high for many patients. Statistics from the Swedish
National Board of Health and Welfare show that in 2019, 3 549 bipolar patients were hospitalized in
closed psychiatric clinics in Sweden. The total amount of care time for all patients was 103,016
days, equaling 29.02 days per patient in 2019. The number of days has also increased from 2 200
days in 1998 to 3 540 days in 2019 (Socialstyrelsen, 2020).
It is well documented how the environment design affects mood and can reduce stress in
healthcare facilities (Dijkstra, Pieterse, & Pruyn, 2008). In 2018 a concept program was produced
as a guideline of the architectural planning of psychiatric clinics (PTS, Chalmers, & et al., 2018).
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The guidelines emphasize the benefits of daylight, but it also encourages the use of circadian light.
Artificial light is recommended to be soft, even, and indirect. (PTS, Chalmers, & et al., 2018)
Due to the high risk of self-harm within the bipolar patient group (American Psychiatric Association,
2021), patient rooms must be without any dangerous objects or potential risk factors, including light
fixtures. The Behavioral Health Design guide from 2018 list these requirements for lighting fixtures
in patient rooms:
- Tamper-resistant
- Polycarbonate prismatic lenses secured either with tamper-resistant screws or fixed
- Vandal-resistant
- Secured recessed downlights
- No glass parts accessible
- Avoid the use of lose objects, including desk lamps
- Avoid the institutional appearance of light fixtures
(Hunt, et al., 2018)
6. Standards and Recommendations
6.1 Patient rooms recommendation from Lighting guide 2: Lighting for healthcare premises
There is no specific standard for lighting in healthcare environments from a patient’s point of view.
For work environments in healthcare, Sweden uses the EN 12464-1:2011 (Arbetsmiljöverket,
2021). The Chartered Institution of Building Service Engineers, an international engineer society,
has presented specific guidelines for patient room light levels in Lighting Guide 2: Lighting for
healthcare premises. It presents light thresholds, horizontally measured in photometric lux.
- Reading bed light for the patient: 300 lux – the light switch shall be easily reached from the bed
- General lighting: 100 lux and a color rendering index, CRI, of Ra80
- General nursing: 300 lux
- Night light: 5 lux
(The Society of Light and Lighting, 2019)
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Specifically for single-bed mental health patient rooms, the guide recommends lower light levels,
150/100/5 lux, with the main difference that the general light level is 150 lux, instead of 300 lux.
(The Society of Light and Lighting, 2019).
6.2 Manchester Recommendations
Melanopic illuminance defines the magnitude of human circadian responses under a wide range of
conditions. Current research suggests Melanopic Equivalent to Daylight (M-EDI) to be the most
reliable measurement for the circadian and neurological impact of light (Lucas et al., 2013). Since
the values are very high in the melanopic sensitivity, the numbers used are defined using a similar
calculation method to the common photometric lux (Altenberg, 2019). IEC defines M-EDI
as "illuminance, produced by radiation conforming to standard daylight (D65), that provides an
equal α-opic irradiance as the test source" (CIE, 2020). I.e., M-EDI assess the potential for the
neurological and circadian impact of ocular light. In 2020, the 2nd International Workshop on
Circadian and Neurophysiological Photometry was held in Manchester, where recommended levels
of M-EDI levels were presented (Brown et al., 2020). The results are published but not yet peer
reviewed. They are, however, the only recommendations available, so they will be used as a
reference guide in this thesis.
All M-EDI measurements should be made vertically at eye level 1.2 m from the ground.
Recommended M-EDI levels for working stations:
- Daytime M-EDI minimum 250 lux.
- Evening M-EDI maximum 10 lux. At least three hours before bedtime. 10 lux is also
recommended as a maximum in case of nighttime activities.
- Night M-EDI maximum 1 lux as not to suppress melatonin during bedtime.
(Brown et al., 2020)
These recommendations are suggested for healthy people (Brown et al., 2020) but will be used as
a guideline also for bipolar patients in this thesis.
6.3 Temporal Light Modulation
Besides light levels and circadian impact, light phenomena that, for some people, are health
hazards are Temporal Light Modulation (TLM) and Temporal Light Artefact (TLA) (Boyce, 2014).
CIE defines TLM as “fluctuation in luminous quantity or spectral distribution of light with respect to
time” (CIE, 2021). TLA, commonly known as flicker, refers to the perceived, visible changes of
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light fluctuation. Due to the Swedish AC power grid supplying electricity of 50 Hz, e.g., fluorescent
lights are turned on/off twice per second hence have a frequency of 100Hz (Knez, 2014).
Frequencies beyond 90 Hz are Non-visible TLA (Knez, 2014). Nonvisible TLA, TLM, is
subconsciously registered by the brain but not by our vision (CIE 2020). TLM has shown to cause a
wide range of adverse effects on health, such as: Decreased problem-solving performance and
longer reaction time (Sandström, Bergqvist, & et al., 2002), eyestrain and headache (IEEE, 2015),
negative emotions and less: lively, enthusiastic, elated, excited, euphoric, and peppy (Knez, 2014).
Swedish Work Environment Authority advises creating an adequate lighting situation with no
disturbing flicker (Arbetsmiljöverket, 2021) but does not specify maximum TLM levels. In
September 2021, there will be a new regulation standard announced by the EU Ecodesign
Commission (Przybyla 2020). In the evaluation of the patient rooms, the draft for the EU Ecodesign
will be used as a guideline. A GL spectrometer, being used to record TLM, will be measuring:
SVM - Stroboscopic effect visibility measure. Measuring non-visual TLM from 80Hz to ca 200Hz.
Designed to take the human perception into account (VISOsystem, 2021)
0.4 SVM - the recommended level being applied in the Ecodesign (VISOsystem, 2021). In 0.4 SVM,
25% of the most sensitive people will see flicker 10% of the time (Miller, 2021)
FP - Temporal Modulation or Flicker percentage
8%. - Between 90 Hz and 1 250 Hz. IEEE suggests a regulation of FP from the formula 0.08 x
Frequency. E.g. 100Hz x 0.08 = 8% (IEEE, 2015)
SVM is the measurement of most interest since that is what is to be recommended by the
Ecodesign when there is no visible TLA in neither of the rooms. Flicker percentages are also noted
since that is the measurement that has been used in many previous health-related studies.
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Field study
To get a sense of how well the above recommendations and research factors are implemented in
the patient rooms, a field study of two different patient rooms was performed.
Two arbitrary patient rooms in closed psychiatric clinics for affective disorders were assessed — one
in Karolinska University Hospital in Huddinge and the other in Västervik hospital. For full
information of measurements from the patient rooms see appendix.
7.1 Patient room 1. (p1) Karolinska University Hospital in Huddinge
Figure 1. The two left images show p1 visualized with correct colors and furniture placement as in the original room. The
three right images show a plan view, a perspective view, a side view with room dimensions and luminaire placement.
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Figure 2. The measuring points numbers in red numbers 1-5 and luminaire letters, A-C in blue. Measuring points 1 and 4
are measured horizontally 80 cm from the floor. Measuring points 5, 2, and 3 are measured vertically, 120 cm from the
floor.
Figure 3. Luminaire A. 2911K. CRI 83.1. Ceiling-
Figure 5.Luminaire C and B. B 2605K, CRI 82.4. C
mounted semi-globe.
2537K, CRI 84.1. Wall-mounted semi-globe. C, bed
General light with diffused, widespread distribution.
light, B desk light. General vertical light, diffused,
widespread distribution.
Figure 4. SPD of light source in luminaire A and C. Figure 6. SPD of light sources in luminaire B. Image
Image from GL Optics Spectis spectrometer. The major from GL Optics Spectis spectrometer. The major
peaks are in 612 nm(180mW/m²/nm) and 545nm distribution is around 600 nm. It peak is at 609 nm
(133mW/m²/nm). 480 nm is low of 9mW/m²/nm. (78mW/m²/nm) The short-wave spectra peaks at
453nm, (20mW/m²/nm) and a decrease to 10mW/m²
/nm around 480 nm.
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7.2 Patient room 2. (p2) Västervik hospital
Figure 7. The left images show p2 visualized with correct colors and furniture placement as in the original room. The three
right images show a plan view, a perspective view and a side view room dimensions and luminaire placement.
Figure 8. The measuring points numbers in red numbers 1-5 and luminaire letters A-D in blue. Measuring points 1 and 4
are measured horizontally 80 cm from the floor. Measure points 5, 2 and 3 are measured vertically, 120 cm from the floor.
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Figure 9. Luminaire A, B, D. A. 2964K, B: 2725K, D:
3017K. Ceiling mounted semi-globes. General light with Figure 10. Luminaire C. 2721K Wall mounted bed light.
diffused, widespread distribution. Two in the room, one Focused light, narrow distribution.
in the bathroom
Figure 11. SPD curve for light source in luminaire A, B, Figure 12. SPD curve for light source in Luminaire C.
D. Image from GL Optics Spectis spectrometer. The Image from GL Optics Spectis spectrometer. The major
major peak is at 605 nm (326mW/m²/nm). The short- peak is at 614 nm (809mW/m²/nm. The short-wave
wave spectra peaks at 456 nm (168mW/m²/nm), and a spectra peaks at 449nm (278mW/m²/nm) and a
decrease around 480 nm (86mW/m²/nm). decrease around 480 nm (106mW/m²/nm).
p1 and p2 are similar in size, approximately 15m², but p2 has a bathroom and p1 a closet. Both
contain a bed, a desk, a chair, and two windows see figures 2 and 7. The walls are painted in
saturated colors, p1 in green hues and p2 in blue hues. They each have three luminaires, p2 also
has one luminaire in the bathroom see figures 7 and 8, but it did not affect the measurements
since the door was closed. The luminaires are placed slightly differently, especially luminaire B that
is wall mounted in p1, see figure 5. The luminaires are all tamper and vandal resistance and made
in plastic. In both patient rooms, the color temperatures are warm and all light sources, but C in p2,
have soft, diffused, widespread light distribution. The spectral power distribution (SPD) curves of
the light sources are quite smooth except for light sources A and C in p1 with spiky curves;
see figures 4-6 and 11-12. They all contain short wavelengths, but most of them lack wavelengths
around 480 nm. The light sources of p1 show how the SPD can differ even if the color temperature
is similar (∼2700K); see figures 3-6.
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7.3 V/P-theory of the light situation in both patient rooms
The evaluation is made by the author with all luminaires on, from sitting position 4 in figure 2 and 8.
Figure 13. V/P-theory answered by the author, n=1. Each of the seven factors of light answers good to bad from 1-5
(shows in square shape), and each of the poles that are stronger from 1-5, e.g., dark-bright (shows in a circular shape).
The circles and squares do not show scale. The horizontal dotted line is the centerline.
In summary, the seven factors lean towards a negative (poor) visual experience see figure 13.
Reflections in p2 and levels of light are ranked highest. Due to the eye's ability to adapt, the room is
perceived as “good” simultaneously as the perceived level of light is dark. The most significant
difference between the two patient rooms is uniformity, where p1 is perceived as entirely varied, but
p2 is perceived as almost uniform.
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7.4 Measurements
The measurements are performed using a GL Optics Spectis spectrometer. Field study for p1 is
performed 2021-04-14 around 21.30. Field study p2 is performed 2021-04-07 around 14.30.
In p2, the daylight is partly blocked by blinds, and the affecting daylight is subtracted from
measurements. Measurements are made both vertically and horizontally, see figures 2 and 8 for
specifications. All results can be seen in the appendix.
Figure 14. The measuring points for illumination are 1. pillow height 2. Room center 3. Desk 4. Chair 5. Center of bed. Lux
levels from measure points compared to recommendations for both general patient rooms and recommendation from
behavior health rooms (The Society of Light and Lighting, 2019)
Figure 15. The measuring points for M-EDI levels are 1. pillow height 2. Room center 3. Desk 4. Chair 5. Center of bed.
M-EDI levels in the patient rooms are compared to recommendations for, daytime, evening, and night (Brown et al.,
2020).
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According to recommendations of illuminance, some levels are sufficient in the patient rooms, see
figure 14. 300 lux is recommended for general patient rooms are nearly achieved in p2 measure
point 2, but the other measure points are far from that level. In p2 all measuring points reach an
illumination of 100 lux, which is the recommendation for patient rooms in behavioral clinics. p1 fails
in all but one measuring point to reach 100 lux. No measuring point in neither room has low enough
illumination for the recommended night level of 5 lux. Maximum M-EDI is measured as 123 lux. 9
lux measured in p2 with multiple light sources from room center 2. Minimum M-EDI is measured
as 10.7 lux in p1 with a single light source.
The light sources in the patient rooms provide a frequency of 100Hz, a result of the Swedish 50Hz
AC (Knez 2014). No modulation of light is visible. Yet TLM beyond the Ecodesign recommended
maximum of 0.4 SVM (VISOsystem, 2021) is measured in all light sources but light source C in p1
with 0.35 SVM and light source C in p2 an SVM of 0.008. The FP is beyond the IEEE’s
recommendation (IEEE, 2015) of 8% in all but one light source, C in p2.
Figure 16 TLM-levels, SVM and FP, from measuring points 1-5 from both patient rooms,
compared to recommendations of SVM-levels from Ecodesign and FP-levels from IEEE.
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7.5 Evaluation of patient rooms
There are three luminaires in each room. In p1, the luminaries are the same but mounted differently
and with different light sources, making the SPD curves differ. In p2, only C differs. Therefore, they
do not vary in illumination levels or light distribution in any significant way. The directionality of the
luminaires is mainly from above, except the C and B in p1 and C in p2 that are wall-mounted,
hence vertically distributed. They do not reach recommended lux levels for generic hospital patient
rooms see figure 14 but reach the recommended levels of 150/50/5 lux recommendation for
mental hospitals (The Society of Light and Lighting, 2019). The M-EDI levels in the patient rooms
are far from reaching recommendations shown in figure 15. Daytime recommendation of 250 M-
EDI and evening recommendation of 10 M-EDI derives from the Manchester meeting’s conclusions
(Brown et al., 2020). Most of the luminaires in the room do not reach the recommended levels of
TLM. Figure 16 shows light sources A in p1 and p2 light source B in p2 are close to FP of 35% that
has previously shown to be a major trigger for headaches (IEEE, 2015).
All luminaires appear to be following the recommended security and hygiene aspects and the
majority of the light sources have a soft and even light distribution. The luminaires fail in having the
recommended non-institutional appearance.
7. Improved design for patient rooms
“It is the unqualified result of all my experience with the sick, that second only to their need of fresh air
is their need of light; that, after a close room, what hurts them most is a dark room. And that it is not
only light but direct sunlight they want. I had rather have the power of carrying my patient about after
the sun, according to the aspect of the rooms, if circumstances permit, than let him linger in a room
when the sun is off.”
(Nightingale, 2005)
The foundation for the improved design is a circadian light scheme with dynamic light that changes
through the day. The light design mimics the natural daylight inspired by Florence Nightingale’s
words above together with literature research.
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The size of the room designed is based on the approximate size of the two field study rooms. The
number of luminaires in the room is the same as in the field study. The number and type of
furniture pieces are similarly based on the furniture in the field study.
Figure 17. Improved light design for a patient room inhabited by bipolar patients. Three luminaire types, shown as
symbols. Luminaire type is stated but no specifications of brands.
8.1 Light intensity and direction of color
The base design of the total amount of light from all luminaires follows the Manchester
recommendation of minimum M-EDI 250 lux during the day, maximum M-EDI 10 lux during the
evening, and maximum M-EDI 1 lux, during the night (Brown et al., 2020). As the natural light
differs throughout the day, with different color temperatures of different times, so shall the color
temperatures of artificial light vary in the patient rooms. The light intensity of all luminaires is
changing from bright in the morning to gradually darker in the evening in a uniform manner. The
direction of light is similarly diverse from above and beyond, depending on the time of day. The
majority of light illuminates from above, bright and short wavelengths in the morning. The majority
of light illuminates from below in long wavelengths during the evening. All light illuminates from
below in only short wavelengths during the night. The cold colors are based on the knowledge of
ipRGC’s main triggers in short wavelength, peaking in 480 nm (Boyce, 2014). The later in the day,
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the less short wavelengths, and instead amber and warm temperatures as not to suppress the
melatonin in the night.
Color temperatures and direction
Figure 18. Shows the color scheduele of a day, similar to the movement and colorshift of the sun. In the morning the light
comes mainly from above high illumination and a short wavelegts, cold color temperatures, in the evening the light comes
mainly from below, with low illumination, long wavelengths and warm color temperature.
Color temperatures and Spectra Power Distribution
Figure 19. The upper image shows the color schedule of a day in a patient room, with approximately time in relation to
color temperature of the light. The lower images show the eligible SPD curves of each color temperature through the day.
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Light and color test
Figure 20. Shows a surface
illuminated by two luminaires, one
from a center position, one from
below. The two lower images show
the center luminaire in different Figure 21. Nine different color and light combinations, mimicking the color
intensities, mimicking the sun. and variety of the sky.
8.2 Suggested luminaires
The improved light design suggests using LED light sources, with an even SPD, as close to natural
light's SPD as possible. It suggests the LEDs are programmable, with an SPD that varies
throughout the day to achieve a varied light. Figure 19 shows a visionary scenario of how the SPD
varies.
All luminaires are temper and vandal resistant, and all visible parts are made of polycarbonate. The
use of polycarbonate creates uniform surfaces that simplify maintenance and hygiene aspects. The
ceiling luminaire and the bed luminaire figures 21 and 24 both have two light sources, enabling two
types of light distribution: direct and indirect. Hansen, a Danish professor in light design from
Aalborg University, has defined this duality of light as one of the main qualities of daylight. She titles
this double dynamic lighting (Hansen & Mathiasen, 2020). The artificial light in the patient room
provides variations of both color and light distribution to achieve double dynamic lighting.
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Ceiling Luminaire - Daytime lights
The primary purpose of the ceiling luminaire is to give a double dynamic general light to the patient
room, mainly during the daytime. It produces an indirect, diffuse light and a sharp, direct light that
projects a square that resembles a window reflection. During the evenings, it is also active but
rather as a reddish effect light than functional as an illuminator.
Figure 22. Shows a section view of the ceiling luminaire and its two light sources, creating a dual light distribution. The
direct light is achieved by a moving projector that enables the projection of a window reflection. The diffused light is
created by LEDs with widespread light distribution.
Figure 23. Shows snapshots of the ceiling luminaire. The light direct distributed is mimicking the sun entering a window,
projecting a sharp reflection. The reflection moves slowly throughout the room in a 12-hour pattern. The color is variable
according to the color schedule.
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Cove luminaire from above - Daytime lights
The primary purpose of the cove light is to create a second layer of light. The secondary objective is
to add to the total illumination levels of the room. The wall illumination creates vertical illumination.
Figure 24. The left image shows a section view, the right image, a front view of linear light, and the ceiling moldings.
Linear light in two directions towards the wall and towards the ceiling. The light color changeable according to schedule.
Figure 25 . Shows the different directionality of the linear light, along with the ceiling, along the wall, and combined.
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Cove luminaires from below - Evening lights
The primary purpose of the low cove light is to act as an evening light, with warm-colored light from
below.
Figure 26. The left image shows a section view, right image a front view of linear light along with the floor moldings. The
light color changeable according to the color schedule. The light is turned off during the night but turned on by censors if
movement appears.
Figure 27. Show snapshots of the cove luminaire in two red hues, blue depleted without 480 nm wavelength, maximum
ambient M-EDI 1 lux, during the night (Brown et al., 2020).
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Bed light
The bed light has a dual function by acting as a light therapy box and as a reading light. The
reading light is manually controlled by an on/off button reachable from the bed. When active, it
follows the overall color schedule.
Figure 28. Shows a section view and a front view of the bed light. Its double light sources create the possible bright
wakeup light and a conventional reading light with narrow distribution.
Figure 29. Show snapshots of the bed luminaire dual function of bright wake-up light and lower intensity reading light,
following the color schedule and total illumination levels depending on the patient’s needs. The wake-up light can be as
bright as a light therapy box of 10 000 lux, in a maximum of one hour (Boyce, 2014).
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8.3 Light program
Throughout a 24-hour day, the color of light and intensity of light will vary. It will happen in slow,
unnoticeable fades along the day. To fit the diversity of the patient group, the light design is
suggested to be divided into three different variations: one neutral state, one manic state, and one
depressive state. A panel on the wall is intended to turn on the program manually in relation to the
patient’s bedtime and depending on the state of the patient. In order not to suggest too clinical
terms, they are called Waking aid (for depressive state), Sleeping aid (for manic state), and then the
third option if the patient is neither, called Neutral.
Figure 30. A program can be decided depending on the patient’s state. In order not to suggest too clinical terms, they are
called Waking aid (for depressive state), Sleeping aid (for manic state), and then the third option if the patient is neither,
called Neutral. Due to the great variation of sensitivity, the maximum light output must be able to dim down. The image
shows an example of the Neutral program in use, dimmed to ca 70% intensity.
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Neutral state – Neutral program
The Neutral light program aims to sustain a healthy circadian rhythm by letting the artificial light
mimic daylight.
Figure 31. Shows the color schedule of a day in the neutral state. The background of the lower image is the primary color,
and the sun its double dynamic contrast that is achieved by the ceiling light. The sun also represents the light intensity,
expanding during the morning.
Morning Day Evening
10000-17000K in the morning 4600K throughout the day. 250 1800K in the evening at least 3
reaching minimum 250 M-EDI, M-EDI, with an SPD that is richer hours before bedtime reaching 10
with a majority of light peaking at in the shortwave spectra. M-EDI. With a SPD that is richer in
480 nm, 8 hours after sleep the longer wavelengths.
onset.
Night
1700 K 0- 5 lux during the night
Figure 32. Shows the desired SPDs of the total light output through the day. Full spectra with the peak in shortwaves
(especially 480) during the morning, an even, full spectra during the day, and longwave spectra during the evening.
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Daytime Evening
Figure 33. Shows
a symbol of a
dimming
possibility, that
enable patient to Figure 34. Two snapshots of a day scenario and an evening scenario. During the day, bright light
lower the light from above is employed, richer in the short wavelength spectra. During the evening, dimmed light
intensity of the mainly from below and with mostly long wavelengths.
entire light
program.
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Depressive state – Waking aid program
The purpose of the Waking aid program is to give equivalent bright daylight in the morning to a
depressive patient and sustain a healthy circadian rhythm.
Figure 35. Shows the author illuminated in blue light, symbolizing a depressive state, aiming for happiness.
Daytime Evening
Figure 36 Shows a
symbol of a
dimming possibility,
that enable patient
.
to lower the light
intensity of the Figure 37. Two snapshots of a day in the “Waking aid program.” A morning scenario with bed light
entire light of 10 000 lux and general light of cold temperature linear and the general luminaire of the double
program. dynamic of direct and diffused bright light. The right image shows an evening scenario with long
wavelengths of light, mainly in the lower regions of the room and low illumination levels.
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Figure 38. Shows the color schedule of a day in the depressive state. The background of the lower image is the primary
color, and the sun its double dynamic contrast that is achieved by the ceiling light. The sun also represents the light
intensity, expanding during the morning with a light therapy brightness in the morning.
Morning Day Evening
Bed light of 10 000 lux, 17000K 4600K throughout the day. 250 1800K in the evening at least 3h
with a majority of light peaking at M-EDI, with an SPD that is richer before bedtime reaching 10 M-EDI.
480nm for 1 hour, 8 hours after in the shortwave spectra. With an SPD that is richer in the
sleep onset. (Boyce, 2014) longer wavelengths.
Followed by general light of
10000-17000K during the rest of Night
the morning reaching minimum 1700 K 0- 5 lux during the night.
250 M-EDI, with a majority of maximum 5 M-EDI.
light peaking at 480nm.
Figure 39. Shows the desired SPDs of the total light output through the day in the waking aid program. Full spectra with
a clear peak in shortwaves (especially 480nm) during the morning, an even, full spectra during the day, and longwave
spectra during the evening.
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Manic state – sleeping aid
The purpose of the Sleeping aid program is to block short wavelengths in the latter part of the day
and to sustain a healthy circadian rhythm.
Figure 40. Shows the author illuminated in amber light, symbolizing a manic state, aiming for a dampened mood.
Daytime Evening
Figure 41. Shows
a symbol of a
dimming possibility,
that enable patient
to lower the light
Figure 42. Two snapshots from a day in the “Sleep aid program.” The morning scenario, with bright
intensity of the
light avoiding short wavelengths, especially 480nm. The evening scenario shows a low luminosity,
entire light
mainly long wavelengths, and light from a low direction.
program.
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Figure 43. Shows the color schedule of a day in the manic state. The background of the lower image is the primary color,
and the sun its double dynamic contrast that is achieved by the ceiling light. The sun also represents the light intensity,
expanding during the morning to reach the M-EDI recommendations. In the manic state, the blue mitigates already during
midday. The night is completely dark.
Morning Day
Evening
10000 K in the morning reaching 2700 K throughout the day. 250
No short wavelengths for 14 hours
maximum 250 M-EDI, 8 hours M-EDI, with an SPD that is richer
in the longwave spectra. Blocked Night
after sleep onset.
the 480 nm wavelengths and Total darkness, during a “normal”
decreased short wavelengths sleep time of about 8 hours.
(Kaplan, 2020).
Figure 44. Shows the desired SPDs of the total light output through the day in the sleeping aid program. Full spectra)
during the morning, and even long wavelengths during the day and only low spectra distribution in the short wave spectra
during the evening during the day, and longwave spectra during the evening.
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8.4 The improved patient room design visualized
Figure 45. A snapshot from the patient’s point of view on how the improved light design could appear in the middle of the
day.
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8. Discussion
9.1 Delimitations
The focus of the thesis is on bipolar patients and their lighting environment. There has not been
any literature review regarding light effects on other patient groups occupying the rooms, i.e.,
potential additional light needs are not being considered. Nevertheless, the light program in the
improved design provides a neutral state based on recommendation for circadian light for all
people, hence could be used for other patient groups.
Since access to the field study patient rooms is very limited, the measurements and evaluation are
only performed once in each room.
The influence of daylight in the patient rooms is not put into consideration. The variation of daylight
hours in Sweden is significant. Artificial light is a constant regardless of season, directionality, floor
level, and time of day. The thesis aims to provide a general recommendation on a light design for
bipolar patients- regardless of location is thereby focusing on the artificial light only. The fact that
Sweden carries out long hours of darkness during the winter season resulting in the dependency on
artificial light also motivates the limitation to artificial light.
The improved light design will only be taken to the concept phase of a design process, and
therefore no specifications of luminaire choices will be presented.
9.2 The improved design
Negative effects of sleep loss, together with the hypothesis that bipolar disease originates from
sleep disturbances (Gold & Sylvia, 2016), motivates the light design in a patient room to promote
sleep regularity. From a light design perspective, the most plausible approach to achieve this is by
addressing light that corresponds to circadian responses. One way of addressing circadian light is
to revert to the qualities of natural light. Nightingale realized the healing effect of sunlight in the
19th century (Nightingale, 2005), since then, its biological effect on the human body has been
explained by discovering the ipRGC photoreceptor. For bipolar patients, this is being confirmed, e.g.,
by the positive effects of depressed bipolar patients exposed to bright morning light (Benedetti,
Colombo, & et al., 2001).
The field study showed that the rooms are overall too dark. Even though p2 reaches some of the
recommended levels of behavioral patient room (The Society of Light and Lighting, 2019), see
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figure 10, light levels are far from reaching the recommendations of melatonin impact suggested
M-EDI daytime recommendations (Brown et al., 2020). The low light levels are also confirmed
through the perceived brightness level assessed in the V/P- evaluation. Both rooms have windows
with access to daylight, affecting the overall illumination. One field study was performed after
sunset and the other during daytime. The daylight illumination was subtracted from the
measurements but could not be ignored in the V/P-theory. Yet, one base of visual perception is its
adaption and relation to compound light impacts. The perception of light with no natural light is
affected by previous light exposure, hence the perception of e.g. darkness or brightness is relative
to the situation.
9.3 Sun-like design
The gathered information from the literature review leads to the assumption that light could have a
healing effect on bipolar patients and could therefore motivate a greater focus on light design in
behavior patient rooms. Even though clinical evidence is still scant according to the Swedish agency
for health technology assessment and assessment of social services (SBU, 2007), it is not
unreasonable to include a therapeutical aim in the light design for bipolar patient rooms. The
therapeutic aspiration stems from the knowledge of the ipRGCs’ relationship to light and the
triggering of physiological responses, and the positive effects of light variations from studies on
bipolar patients. Perhaps the impact of light could reduce the use of sleep-promoting medicine or
at least be used as a supplement.
Since the field study showed no similarities to a dynamic circadian light in the rooms, this is
suggested in the improved design. The use of circadian light incorporates the knowledge of
directionality and the spectra distribution on melatonin suppression (CIE, 2019). The improved light
design mimics the sun. Dim, long wavelengths illuminating from below simulates the warm sunset
light in the latter part of the day, and bright short-wavelength illumination from above imitates the
blue sky and zenithal sun during the day. Like natural light, the improved light design uses a
dynamic light where intensity and color subtly shift constantly throughout a day with a 24-hour
schedule.
10.4 Light program
CIE recommends “The right light at the right time” (CIE, 2019). The right light for bipolar patients
could be one that emphasizes a normal circadian cycle, as sleep is central to the condition. During
illness episodes, the sleep disturbances seem to peak after a previous escalation (Kaplan, 2020).
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Phase shifts corresponding to hyper sleep or sleep deprivation are thereby desirable. The right light
is also a dynamic light design as the needs in the different episodes differ significantly. A light
program for the different phases is therefore suggested. The light program has a Neutral state that
the two poles use as a starting point. The neutral program could potentially be used for other
patient groups occupying the patient rooms, but the main idea with the neutral program is to have a
base from where the other programs can be adjusted. The Neutral state uses a light schedule
following the Manchester M-EDI recommendations. The programs show recommended color
temperatures and light intensities. This is based on knowledge of light therapy light levels (Oishi,
Glaeson, & et al., 2019), but as seen in the field study, color temperature is insufficient to tell the
biological impact of light. Irradiance SPD curves might vary even when color temperatures are
similar see figure 3-6 as shown from the light sources in p1. This motivates to address the SPD
instead of color temperature. Since this is not common for light therapy, the improved light design
states both color temperature and SPD recommendations. As there is a significant variation in
photosensitivity (Brown et al., 2020), the improved design suggests a panel that can dim the entire
program percentage. The possibility is also an attempt to incorporate the idea of a sense of control,
which is declared by Ulrich, a researcher of health environment design (Andrade & Devlin, 2021).
9.5 Depression
The field study shows the low M-EDI levels in both patient rooms, meaning that the artificial light
has little effect on the circadian function. Since studies showed the importance of bright light in the
mornings for depressive bipolar patients (Benedetti et al., 2001), the improved design suggests a
bed light with dual function. First, the luminaire will act as a lightbox, illuminate 10 000 lux, used in
light therapy (Boyce, 2014). It will use a 17 000K temperature light, even though the color
temperature is rather irrelevant with higher illuminance levels (Boyce, 2014). Each small effect will
be counted for and therefore used in the design. After the hour-long light shower, the luminaire will
act as a regular bed light with an on/off button and follow the day's main color schedule.
The bright light in the morning and the short-wavelength light during the day attempt to stabilize
the possible circadian disruption, which will hopefully lead to improved sleep. Besides sleep aid, the
ipRGCs might also affect mood directly (Kaplan, 2020) and could therefore be good to trigger in a
depressive patient.
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9.6 Manic state light effects
Studies show that avoiding triggering the ipRGCs both leads to better sleep and perhaps also
stabilizing mood directly (Kaplan, 2020) (LeGates, 2014). Regarding ipRGC triggers, the light levels
and colors in the field study are quite suitable for a manic patient during the daytime. However,
since the luminaires are non-dimmable, they are too bright even for healthy persons according to
the maximum M-EDI of 10 lux during the evening (Brown et al., 2020). Therefore, the improved
design suggests a dynamic light that lowers its intensity during the second half of the day. As an
alternative to wearing blue-blocking glasses, the improved light design suggests a light that
excludes the sensitive short wavelengths fully during a period of 14 hours. The length is based on
the dark therapy method, where 14 hours of darkness is being used (Easaki, Objayashi, & et al.,
2020). Total darkness is also suggested, but only during desirable 8 hours of sleep. Keeping
patients in long periods of darkness could have a negative psychological impact and is probably not
needed since the blue-blocking light is employed.
9.7 Luminaires in the field study and the TLM
In the field study, all luminaires seemed to follow the safety and hygiene recommendations (The
Society of Light and Lighting, 2019). Similar functions should be applied in the improved light
design. But the improved light aims to also create luminaires that do not feel institutional but should
rather remind of nature. Another problematic aspect of the luminaires in the field study is their TLM
levels. Luminaire A and B in both patient rooms reached far above the US IEEE’s recommendations
of 8% FP (IEEE, 2015). Their values are also close to the 35% FP, which has been identified by
Wilkins as the peak for causing headaches from 100Hz fluorescents (IEEE, 2015). Searching the
literature for specific effects on bipolar patients from TLM has not yielded any results. But like for
the rest of the population, negative health effects from TLM are likely to appear. Considering the
measurement results, all luminaires except one in p2 should be replaced due to their TLM levels.
Since the improved light design provides a dynamic light, with all dimmable, color-changing LEDs,
there is a risk of more flicker; hence there must be a great consideration regarding this when
deciding upon luminaires and their drivers to avoid this consequence.
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